1 /*
   2  * Copyright (c) 1997, 2023, 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 "precompiled.hpp"
  26 #include "asm/macroAssembler.hpp"
  27 #include "asm/macroAssembler.inline.hpp"
  28 #include "ci/ciReplay.hpp"
  29 #include "classfile/javaClasses.hpp"
  30 #include "code/exceptionHandlerTable.hpp"
  31 #include "code/nmethod.hpp"
  32 #include "compiler/compileBroker.hpp"
  33 #include "compiler/compileLog.hpp"
  34 #include "compiler/disassembler.hpp"
  35 #include "compiler/oopMap.hpp"
  36 #include "gc/shared/barrierSet.hpp"
  37 #include "gc/shared/c2/barrierSetC2.hpp"
  38 #include "jfr/jfrEvents.hpp"
  39 #include "jvm_io.h"
  40 #include "memory/allocation.hpp"
  41 #include "memory/resourceArea.hpp"
  42 #include "opto/addnode.hpp"
  43 #include "opto/block.hpp"
  44 #include "opto/c2compiler.hpp"
  45 #include "opto/callGenerator.hpp"
  46 #include "opto/callnode.hpp"
  47 #include "opto/castnode.hpp"
  48 #include "opto/cfgnode.hpp"
  49 #include "opto/chaitin.hpp"
  50 #include "opto/compile.hpp"
  51 #include "opto/connode.hpp"
  52 #include "opto/convertnode.hpp"
  53 #include "opto/divnode.hpp"
  54 #include "opto/escape.hpp"
  55 #include "opto/idealGraphPrinter.hpp"
  56 #include "opto/loopnode.hpp"
  57 #include "opto/machnode.hpp"
  58 #include "opto/macro.hpp"
  59 #include "opto/matcher.hpp"
  60 #include "opto/mathexactnode.hpp"
  61 #include "opto/memnode.hpp"
  62 #include "opto/mulnode.hpp"
  63 #include "opto/narrowptrnode.hpp"
  64 #include "opto/node.hpp"
  65 #include "opto/opcodes.hpp"
  66 #include "opto/output.hpp"
  67 #include "opto/parse.hpp"
  68 #include "opto/phaseX.hpp"
  69 #include "opto/rootnode.hpp"
  70 #include "opto/runtime.hpp"
  71 #include "opto/stringopts.hpp"
  72 #include "opto/type.hpp"
  73 #include "opto/vector.hpp"
  74 #include "opto/vectornode.hpp"
  75 #include "runtime/globals_extension.hpp"
  76 #include "runtime/sharedRuntime.hpp"
  77 #include "runtime/signature.hpp"
  78 #include "runtime/stubRoutines.hpp"
  79 #include "runtime/timer.hpp"
  80 #include "utilities/align.hpp"
  81 #include "utilities/copy.hpp"
  82 #include "utilities/macros.hpp"
  83 #include "utilities/resourceHash.hpp"
  84 
  85 // -------------------- Compile::mach_constant_base_node -----------------------
  86 // Constant table base node singleton.
  87 MachConstantBaseNode* Compile::mach_constant_base_node() {
  88   if (_mach_constant_base_node == nullptr) {
  89     _mach_constant_base_node = new MachConstantBaseNode();
  90     _mach_constant_base_node->add_req(C->root());
  91   }
  92   return _mach_constant_base_node;
  93 }
  94 
  95 
  96 /// Support for intrinsics.
  97 
  98 // Return the index at which m must be inserted (or already exists).
  99 // The sort order is by the address of the ciMethod, with is_virtual as minor key.
 100 class IntrinsicDescPair {
 101  private:
 102   ciMethod* _m;
 103   bool _is_virtual;
 104  public:
 105   IntrinsicDescPair(ciMethod* m, bool is_virtual) : _m(m), _is_virtual(is_virtual) {}
 106   static int compare(IntrinsicDescPair* const& key, CallGenerator* const& elt) {
 107     ciMethod* m= elt->method();
 108     ciMethod* key_m = key->_m;
 109     if (key_m < m)      return -1;
 110     else if (key_m > m) return 1;
 111     else {
 112       bool is_virtual = elt->is_virtual();
 113       bool key_virtual = key->_is_virtual;
 114       if (key_virtual < is_virtual)      return -1;
 115       else if (key_virtual > is_virtual) return 1;
 116       else                               return 0;
 117     }
 118   }
 119 };
 120 int Compile::intrinsic_insertion_index(ciMethod* m, bool is_virtual, bool& found) {
 121 #ifdef ASSERT
 122   for (int i = 1; i < _intrinsics.length(); i++) {
 123     CallGenerator* cg1 = _intrinsics.at(i-1);
 124     CallGenerator* cg2 = _intrinsics.at(i);
 125     assert(cg1->method() != cg2->method()
 126            ? cg1->method()     < cg2->method()
 127            : cg1->is_virtual() < cg2->is_virtual(),
 128            "compiler intrinsics list must stay sorted");
 129   }
 130 #endif
 131   IntrinsicDescPair pair(m, is_virtual);
 132   return _intrinsics.find_sorted<IntrinsicDescPair*, IntrinsicDescPair::compare>(&pair, found);
 133 }
 134 
 135 void Compile::register_intrinsic(CallGenerator* cg) {
 136   bool found = false;
 137   int index = intrinsic_insertion_index(cg->method(), cg->is_virtual(), found);
 138   assert(!found, "registering twice");
 139   _intrinsics.insert_before(index, cg);
 140   assert(find_intrinsic(cg->method(), cg->is_virtual()) == cg, "registration worked");
 141 }
 142 
 143 CallGenerator* Compile::find_intrinsic(ciMethod* m, bool is_virtual) {
 144   assert(m->is_loaded(), "don't try this on unloaded methods");
 145   if (_intrinsics.length() > 0) {
 146     bool found = false;
 147     int index = intrinsic_insertion_index(m, is_virtual, found);
 148      if (found) {
 149       return _intrinsics.at(index);
 150     }
 151   }
 152   // Lazily create intrinsics for intrinsic IDs well-known in the runtime.
 153   if (m->intrinsic_id() != vmIntrinsics::_none &&
 154       m->intrinsic_id() <= vmIntrinsics::LAST_COMPILER_INLINE) {
 155     CallGenerator* cg = make_vm_intrinsic(m, is_virtual);
 156     if (cg != nullptr) {
 157       // Save it for next time:
 158       register_intrinsic(cg);
 159       return cg;
 160     } else {
 161       gather_intrinsic_statistics(m->intrinsic_id(), is_virtual, _intrinsic_disabled);
 162     }
 163   }
 164   return nullptr;
 165 }
 166 
 167 // Compile::make_vm_intrinsic is defined in library_call.cpp.
 168 
 169 #ifndef PRODUCT
 170 // statistics gathering...
 171 
 172 juint  Compile::_intrinsic_hist_count[vmIntrinsics::number_of_intrinsics()] = {0};
 173 jubyte Compile::_intrinsic_hist_flags[vmIntrinsics::number_of_intrinsics()] = {0};
 174 
 175 inline int as_int(vmIntrinsics::ID id) {
 176   return vmIntrinsics::as_int(id);
 177 }
 178 
 179 bool Compile::gather_intrinsic_statistics(vmIntrinsics::ID id, bool is_virtual, int flags) {
 180   assert(id > vmIntrinsics::_none && id < vmIntrinsics::ID_LIMIT, "oob");
 181   int oflags = _intrinsic_hist_flags[as_int(id)];
 182   assert(flags != 0, "what happened?");
 183   if (is_virtual) {
 184     flags |= _intrinsic_virtual;
 185   }
 186   bool changed = (flags != oflags);
 187   if ((flags & _intrinsic_worked) != 0) {
 188     juint count = (_intrinsic_hist_count[as_int(id)] += 1);
 189     if (count == 1) {
 190       changed = true;           // first time
 191     }
 192     // increment the overall count also:
 193     _intrinsic_hist_count[as_int(vmIntrinsics::_none)] += 1;
 194   }
 195   if (changed) {
 196     if (((oflags ^ flags) & _intrinsic_virtual) != 0) {
 197       // Something changed about the intrinsic's virtuality.
 198       if ((flags & _intrinsic_virtual) != 0) {
 199         // This is the first use of this intrinsic as a virtual call.
 200         if (oflags != 0) {
 201           // We already saw it as a non-virtual, so note both cases.
 202           flags |= _intrinsic_both;
 203         }
 204       } else if ((oflags & _intrinsic_both) == 0) {
 205         // This is the first use of this intrinsic as a non-virtual
 206         flags |= _intrinsic_both;
 207       }
 208     }
 209     _intrinsic_hist_flags[as_int(id)] = (jubyte) (oflags | flags);
 210   }
 211   // update the overall flags also:
 212   _intrinsic_hist_flags[as_int(vmIntrinsics::_none)] |= (jubyte) flags;
 213   return changed;
 214 }
 215 
 216 static char* format_flags(int flags, char* buf) {
 217   buf[0] = 0;
 218   if ((flags & Compile::_intrinsic_worked) != 0)    strcat(buf, ",worked");
 219   if ((flags & Compile::_intrinsic_failed) != 0)    strcat(buf, ",failed");
 220   if ((flags & Compile::_intrinsic_disabled) != 0)  strcat(buf, ",disabled");
 221   if ((flags & Compile::_intrinsic_virtual) != 0)   strcat(buf, ",virtual");
 222   if ((flags & Compile::_intrinsic_both) != 0)      strcat(buf, ",nonvirtual");
 223   if (buf[0] == 0)  strcat(buf, ",");
 224   assert(buf[0] == ',', "must be");
 225   return &buf[1];
 226 }
 227 
 228 void Compile::print_intrinsic_statistics() {
 229   char flagsbuf[100];
 230   ttyLocker ttyl;
 231   if (xtty != nullptr)  xtty->head("statistics type='intrinsic'");
 232   tty->print_cr("Compiler intrinsic usage:");
 233   juint total = _intrinsic_hist_count[as_int(vmIntrinsics::_none)];
 234   if (total == 0)  total = 1;  // avoid div0 in case of no successes
 235   #define PRINT_STAT_LINE(name, c, f) \
 236     tty->print_cr("  %4d (%4.1f%%) %s (%s)", (int)(c), ((c) * 100.0) / total, name, f);
 237   for (auto id : EnumRange<vmIntrinsicID>{}) {
 238     int   flags = _intrinsic_hist_flags[as_int(id)];
 239     juint count = _intrinsic_hist_count[as_int(id)];
 240     if ((flags | count) != 0) {
 241       PRINT_STAT_LINE(vmIntrinsics::name_at(id), count, format_flags(flags, flagsbuf));
 242     }
 243   }
 244   PRINT_STAT_LINE("total", total, format_flags(_intrinsic_hist_flags[as_int(vmIntrinsics::_none)], flagsbuf));
 245   if (xtty != nullptr)  xtty->tail("statistics");
 246 }
 247 
 248 void Compile::print_statistics() {
 249   { ttyLocker ttyl;
 250     if (xtty != nullptr)  xtty->head("statistics type='opto'");
 251     Parse::print_statistics();
 252     PhaseStringOpts::print_statistics();
 253     PhaseCCP::print_statistics();
 254     PhaseRegAlloc::print_statistics();
 255     PhaseOutput::print_statistics();
 256     PhasePeephole::print_statistics();
 257     PhaseIdealLoop::print_statistics();
 258     ConnectionGraph::print_statistics();
 259     PhaseMacroExpand::print_statistics();
 260     if (xtty != nullptr)  xtty->tail("statistics");
 261   }
 262   if (_intrinsic_hist_flags[as_int(vmIntrinsics::_none)] != 0) {
 263     // put this under its own <statistics> element.
 264     print_intrinsic_statistics();
 265   }
 266 }
 267 #endif //PRODUCT
 268 
 269 void Compile::gvn_replace_by(Node* n, Node* nn) {
 270   for (DUIterator_Last imin, i = n->last_outs(imin); i >= imin; ) {
 271     Node* use = n->last_out(i);
 272     bool is_in_table = initial_gvn()->hash_delete(use);
 273     uint uses_found = 0;
 274     for (uint j = 0; j < use->len(); j++) {
 275       if (use->in(j) == n) {
 276         if (j < use->req())
 277           use->set_req(j, nn);
 278         else
 279           use->set_prec(j, nn);
 280         uses_found++;
 281       }
 282     }
 283     if (is_in_table) {
 284       // reinsert into table
 285       initial_gvn()->hash_find_insert(use);
 286     }
 287     record_for_igvn(use);
 288     i -= uses_found;    // we deleted 1 or more copies of this edge
 289   }
 290 }
 291 
 292 
 293 // Identify all nodes that are reachable from below, useful.
 294 // Use breadth-first pass that records state in a Unique_Node_List,
 295 // recursive traversal is slower.
 296 void Compile::identify_useful_nodes(Unique_Node_List &useful) {
 297   int estimated_worklist_size = live_nodes();
 298   useful.map( estimated_worklist_size, nullptr );  // preallocate space
 299 
 300   // Initialize worklist
 301   if (root() != nullptr)  { useful.push(root()); }
 302   // If 'top' is cached, declare it useful to preserve cached node
 303   if (cached_top_node())  { useful.push(cached_top_node()); }
 304 
 305   // Push all useful nodes onto the list, breadthfirst
 306   for( uint next = 0; next < useful.size(); ++next ) {
 307     assert( next < unique(), "Unique useful nodes < total nodes");
 308     Node *n  = useful.at(next);
 309     uint max = n->len();
 310     for( uint i = 0; i < max; ++i ) {
 311       Node *m = n->in(i);
 312       if (not_a_node(m))  continue;
 313       useful.push(m);
 314     }
 315   }
 316 }
 317 
 318 // Update dead_node_list with any missing dead nodes using useful
 319 // list. Consider all non-useful nodes to be useless i.e., dead nodes.
 320 void Compile::update_dead_node_list(Unique_Node_List &useful) {
 321   uint max_idx = unique();
 322   VectorSet& useful_node_set = useful.member_set();
 323 
 324   for (uint node_idx = 0; node_idx < max_idx; node_idx++) {
 325     // If node with index node_idx is not in useful set,
 326     // mark it as dead in dead node list.
 327     if (!useful_node_set.test(node_idx)) {
 328       record_dead_node(node_idx);
 329     }
 330   }
 331 }
 332 
 333 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Unique_Node_List &useful) {
 334   int shift = 0;
 335   for (int i = 0; i < inlines->length(); i++) {
 336     CallGenerator* cg = inlines->at(i);
 337     if (useful.member(cg->call_node())) {
 338       if (shift > 0) {
 339         inlines->at_put(i - shift, cg);
 340       }
 341     } else {
 342       shift++; // skip over the dead element
 343     }
 344   }
 345   if (shift > 0) {
 346     inlines->trunc_to(inlines->length() - shift); // remove last elements from compacted array
 347   }
 348 }
 349 
 350 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Node* dead) {
 351   assert(dead != nullptr && dead->is_Call(), "sanity");
 352   int found = 0;
 353   for (int i = 0; i < inlines->length(); i++) {
 354     if (inlines->at(i)->call_node() == dead) {
 355       inlines->remove_at(i);
 356       found++;
 357       NOT_DEBUG( break; ) // elements are unique, so exit early
 358     }
 359   }
 360   assert(found <= 1, "not unique");
 361 }
 362 
 363 void Compile::remove_useless_nodes(GrowableArray<Node*>& node_list, Unique_Node_List& useful) {
 364   for (int i = node_list.length() - 1; i >= 0; i--) {
 365     Node* n = node_list.at(i);
 366     if (!useful.member(n)) {
 367       node_list.delete_at(i); // replaces i-th with last element which is known to be useful (already processed)
 368     }
 369   }
 370 }
 371 
 372 void Compile::remove_useless_node(Node* dead) {
 373   remove_modified_node(dead);
 374 
 375   // Constant node that has no out-edges and has only one in-edge from
 376   // root is usually dead. However, sometimes reshaping walk makes
 377   // it reachable by adding use edges. So, we will NOT count Con nodes
 378   // as dead to be conservative about the dead node count at any
 379   // given time.
 380   if (!dead->is_Con()) {
 381     record_dead_node(dead->_idx);
 382   }
 383   if (dead->is_macro()) {
 384     remove_macro_node(dead);
 385   }
 386   if (dead->is_expensive()) {
 387     remove_expensive_node(dead);
 388   }
 389   if (dead->Opcode() == Op_Opaque4) {
 390     remove_template_assertion_predicate_opaq(dead);
 391   }
 392   if (dead->for_post_loop_opts_igvn()) {
 393     remove_from_post_loop_opts_igvn(dead);
 394   }
 395   if (dead->is_Call()) {
 396     remove_useless_late_inlines(                &_late_inlines, dead);
 397     remove_useless_late_inlines(         &_string_late_inlines, dead);
 398     remove_useless_late_inlines(         &_boxing_late_inlines, dead);
 399     remove_useless_late_inlines(&_vector_reboxing_late_inlines, dead);
 400 
 401     if (dead->is_CallStaticJava()) {
 402       remove_unstable_if_trap(dead->as_CallStaticJava(), false);
 403     }
 404   }
 405   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 406   bs->unregister_potential_barrier_node(dead);
 407 }
 408 
 409 // Disconnect all useless nodes by disconnecting those at the boundary.
 410 void Compile::disconnect_useless_nodes(Unique_Node_List& useful, Unique_Node_List& worklist) {
 411   uint next = 0;
 412   while (next < useful.size()) {
 413     Node *n = useful.at(next++);
 414     if (n->is_SafePoint()) {
 415       // We're done with a parsing phase. Replaced nodes are not valid
 416       // beyond that point.
 417       n->as_SafePoint()->delete_replaced_nodes();
 418     }
 419     // Use raw traversal of out edges since this code removes out edges
 420     int max = n->outcnt();
 421     for (int j = 0; j < max; ++j) {
 422       Node* child = n->raw_out(j);
 423       if (!useful.member(child)) {
 424         assert(!child->is_top() || child != top(),
 425                "If top is cached in Compile object it is in useful list");
 426         // Only need to remove this out-edge to the useless node
 427         n->raw_del_out(j);
 428         --j;
 429         --max;
 430       }
 431     }
 432     if (n->outcnt() == 1 && n->has_special_unique_user()) {
 433       assert(useful.member(n->unique_out()), "do not push a useless node");
 434       worklist.push(n->unique_out());
 435     }
 436   }
 437 
 438   remove_useless_nodes(_macro_nodes,        useful); // remove useless macro nodes
 439   remove_useless_nodes(_parse_predicate_opaqs, useful); // remove useless Parse Predicate opaque nodes
 440   remove_useless_nodes(_template_assertion_predicate_opaqs, useful); // remove useless Assertion Predicate opaque nodes
 441   remove_useless_nodes(_expensive_nodes,    useful); // remove useless expensive nodes
 442   remove_useless_nodes(_for_post_loop_igvn, useful); // remove useless node recorded for post loop opts IGVN pass
 443   remove_useless_unstable_if_traps(useful);          // remove useless unstable_if traps
 444   remove_useless_coarsened_locks(useful);            // remove useless coarsened locks nodes
 445 #ifdef ASSERT
 446   if (_modified_nodes != nullptr) {
 447     _modified_nodes->remove_useless_nodes(useful.member_set());
 448   }
 449 #endif
 450 
 451   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 452   bs->eliminate_useless_gc_barriers(useful, this);
 453   // clean up the late inline lists
 454   remove_useless_late_inlines(                &_late_inlines, useful);
 455   remove_useless_late_inlines(         &_string_late_inlines, useful);
 456   remove_useless_late_inlines(         &_boxing_late_inlines, useful);
 457   remove_useless_late_inlines(&_vector_reboxing_late_inlines, useful);
 458   debug_only(verify_graph_edges(true/*check for no_dead_code*/);)
 459 }
 460 
 461 // ============================================================================
 462 //------------------------------CompileWrapper---------------------------------
 463 class CompileWrapper : public StackObj {
 464   Compile *const _compile;
 465  public:
 466   CompileWrapper(Compile* compile);
 467 
 468   ~CompileWrapper();
 469 };
 470 
 471 CompileWrapper::CompileWrapper(Compile* compile) : _compile(compile) {
 472   // the Compile* pointer is stored in the current ciEnv:
 473   ciEnv* env = compile->env();
 474   assert(env == ciEnv::current(), "must already be a ciEnv active");
 475   assert(env->compiler_data() == nullptr, "compile already active?");
 476   env->set_compiler_data(compile);
 477   assert(compile == Compile::current(), "sanity");
 478 
 479   compile->set_type_dict(nullptr);
 480   compile->set_clone_map(new Dict(cmpkey, hashkey, _compile->comp_arena()));
 481   compile->clone_map().set_clone_idx(0);
 482   compile->set_type_last_size(0);
 483   compile->set_last_tf(nullptr, nullptr);
 484   compile->set_indexSet_arena(nullptr);
 485   compile->set_indexSet_free_block_list(nullptr);
 486   compile->init_type_arena();
 487   Type::Initialize(compile);
 488   _compile->begin_method();
 489   _compile->clone_map().set_debug(_compile->has_method() && _compile->directive()->CloneMapDebugOption);
 490 }
 491 CompileWrapper::~CompileWrapper() {
 492   // simulate crash during compilation
 493   assert(CICrashAt < 0 || _compile->compile_id() != CICrashAt, "just as planned");
 494 
 495   _compile->end_method();
 496   _compile->env()->set_compiler_data(nullptr);
 497 }
 498 
 499 
 500 //----------------------------print_compile_messages---------------------------
 501 void Compile::print_compile_messages() {
 502 #ifndef PRODUCT
 503   // Check if recompiling
 504   if (!subsume_loads() && PrintOpto) {
 505     // Recompiling without allowing machine instructions to subsume loads
 506     tty->print_cr("*********************************************************");
 507     tty->print_cr("** Bailout: Recompile without subsuming loads          **");
 508     tty->print_cr("*********************************************************");
 509   }
 510   if ((do_escape_analysis() != DoEscapeAnalysis) && PrintOpto) {
 511     // Recompiling without escape analysis
 512     tty->print_cr("*********************************************************");
 513     tty->print_cr("** Bailout: Recompile without escape analysis          **");
 514     tty->print_cr("*********************************************************");
 515   }
 516   if (do_iterative_escape_analysis() != DoEscapeAnalysis && PrintOpto) {
 517     // Recompiling without iterative escape analysis
 518     tty->print_cr("*********************************************************");
 519     tty->print_cr("** Bailout: Recompile without iterative escape analysis**");
 520     tty->print_cr("*********************************************************");
 521   }
 522   if ((eliminate_boxing() != EliminateAutoBox) && PrintOpto) {
 523     // Recompiling without boxing elimination
 524     tty->print_cr("*********************************************************");
 525     tty->print_cr("** Bailout: Recompile without boxing elimination       **");
 526     tty->print_cr("*********************************************************");
 527   }
 528   if ((do_locks_coarsening() != EliminateLocks) && PrintOpto) {
 529     // Recompiling without locks coarsening
 530     tty->print_cr("*********************************************************");
 531     tty->print_cr("** Bailout: Recompile without locks coarsening         **");
 532     tty->print_cr("*********************************************************");
 533   }
 534   if (env()->break_at_compile()) {
 535     // Open the debugger when compiling this method.
 536     tty->print("### Breaking when compiling: ");
 537     method()->print_short_name();
 538     tty->cr();
 539     BREAKPOINT;
 540   }
 541 
 542   if( PrintOpto ) {
 543     if (is_osr_compilation()) {
 544       tty->print("[OSR]%3d", _compile_id);
 545     } else {
 546       tty->print("%3d", _compile_id);
 547     }
 548   }
 549 #endif
 550 }
 551 
 552 #ifndef PRODUCT
 553 void Compile::print_ideal_ir(const char* phase_name) {
 554   ttyLocker ttyl;
 555   // keep the following output all in one block
 556   // This output goes directly to the tty, not the compiler log.
 557   // To enable tools to match it up with the compilation activity,
 558   // be sure to tag this tty output with the compile ID.
 559   if (xtty != nullptr) {
 560     xtty->head("ideal compile_id='%d'%s compile_phase='%s'",
 561                compile_id(),
 562                is_osr_compilation() ? " compile_kind='osr'" : "",
 563                phase_name);
 564   }
 565   if (_output == nullptr) {
 566     tty->print_cr("AFTER: %s", phase_name);
 567     // Print out all nodes in ascending order of index.
 568     root()->dump_bfs(MaxNodeLimit, nullptr, "+S$");
 569   } else {
 570     // Dump the node blockwise if we have a scheduling
 571     _output->print_scheduling();
 572   }
 573 
 574   if (xtty != nullptr) {
 575     xtty->tail("ideal");
 576   }
 577 }
 578 #endif
 579 
 580 // ============================================================================
 581 //------------------------------Compile standard-------------------------------
 582 
 583 // Compile a method.  entry_bci is -1 for normal compilations and indicates
 584 // the continuation bci for on stack replacement.
 585 
 586 
 587 Compile::Compile( ciEnv* ci_env, ciMethod* target, int osr_bci,
 588                   Options options, DirectiveSet* directive)
 589                 : Phase(Compiler),
 590                   _compile_id(ci_env->compile_id()),
 591                   _options(options),
 592                   _method(target),
 593                   _entry_bci(osr_bci),
 594                   _ilt(nullptr),
 595                   _stub_function(nullptr),
 596                   _stub_name(nullptr),
 597                   _stub_entry_point(nullptr),
 598                   _max_node_limit(MaxNodeLimit),
 599                   _post_loop_opts_phase(false),
 600                   _inlining_progress(false),
 601                   _inlining_incrementally(false),
 602                   _do_cleanup(false),
 603                   _has_reserved_stack_access(target->has_reserved_stack_access()),
 604 #ifndef PRODUCT
 605                   _igv_idx(0),
 606                   _trace_opto_output(directive->TraceOptoOutputOption),
 607 #endif
 608                   _has_method_handle_invokes(false),
 609                   _clinit_barrier_on_entry(false),
 610                   _stress_seed(0),
 611                   _comp_arena(mtCompiler),
 612                   _barrier_set_state(BarrierSet::barrier_set()->barrier_set_c2()->create_barrier_state(comp_arena())),
 613                   _env(ci_env),
 614                   _directive(directive),
 615                   _log(ci_env->log()),
 616                   _failure_reason(nullptr),
 617                   _intrinsics        (comp_arena(), 0, 0, nullptr),
 618                   _macro_nodes       (comp_arena(), 8, 0, nullptr),
 619                   _parse_predicate_opaqs (comp_arena(), 8, 0, nullptr),
 620                   _template_assertion_predicate_opaqs (comp_arena(), 8, 0, nullptr),
 621                   _expensive_nodes   (comp_arena(), 8, 0, nullptr),
 622                   _for_post_loop_igvn(comp_arena(), 8, 0, nullptr),
 623                   _unstable_if_traps (comp_arena(), 8, 0, nullptr),
 624                   _coarsened_locks   (comp_arena(), 8, 0, nullptr),
 625                   _congraph(nullptr),
 626                   NOT_PRODUCT(_igv_printer(nullptr) COMMA)
 627                   _dead_node_list(comp_arena()),
 628                   _dead_node_count(0),
 629                   _node_arena(mtCompiler),
 630                   _old_arena(mtCompiler),
 631                   _mach_constant_base_node(nullptr),
 632                   _Compile_types(mtCompiler),
 633                   _initial_gvn(nullptr),
 634                   _igvn_worklist(nullptr),
 635                   _types(nullptr),
 636                   _node_hash(nullptr),
 637                   _late_inlines(comp_arena(), 2, 0, nullptr),
 638                   _string_late_inlines(comp_arena(), 2, 0, nullptr),
 639                   _boxing_late_inlines(comp_arena(), 2, 0, nullptr),
 640                   _vector_reboxing_late_inlines(comp_arena(), 2, 0, nullptr),
 641                   _late_inlines_pos(0),
 642                   _number_of_mh_late_inlines(0),
 643                   _print_inlining_stream(new (mtCompiler) stringStream()),
 644                   _print_inlining_list(nullptr),
 645                   _print_inlining_idx(0),
 646                   _print_inlining_output(nullptr),
 647                   _replay_inline_data(nullptr),
 648                   _java_calls(0),
 649                   _inner_loops(0),
 650                   _interpreter_frame_size(0),
 651                   _output(nullptr)
 652 #ifndef PRODUCT
 653                   , _in_dump_cnt(0)
 654 #endif
 655 {
 656   C = this;
 657   CompileWrapper cw(this);
 658 
 659   if (CITimeVerbose) {
 660     tty->print(" ");
 661     target->holder()->name()->print();
 662     tty->print(".");
 663     target->print_short_name();
 664     tty->print("  ");
 665   }
 666   TraceTime t1("Total compilation time", &_t_totalCompilation, CITime, CITimeVerbose);
 667   TraceTime t2(nullptr, &_t_methodCompilation, CITime, false);
 668 
 669 #if defined(SUPPORT_ASSEMBLY) || defined(SUPPORT_ABSTRACT_ASSEMBLY)
 670   bool print_opto_assembly = directive->PrintOptoAssemblyOption;
 671   // We can always print a disassembly, either abstract (hex dump) or
 672   // with the help of a suitable hsdis library. Thus, we should not
 673   // couple print_assembly and print_opto_assembly controls.
 674   // But: always print opto and regular assembly on compile command 'print'.
 675   bool print_assembly = directive->PrintAssemblyOption;
 676   set_print_assembly(print_opto_assembly || print_assembly);
 677 #else
 678   set_print_assembly(false); // must initialize.
 679 #endif
 680 
 681 #ifndef PRODUCT
 682   set_parsed_irreducible_loop(false);
 683 #endif
 684 
 685   if (directive->ReplayInlineOption) {
 686     _replay_inline_data = ciReplay::load_inline_data(method(), entry_bci(), ci_env->comp_level());
 687   }
 688   set_print_inlining(directive->PrintInliningOption || PrintOptoInlining);
 689   set_print_intrinsics(directive->PrintIntrinsicsOption);
 690   set_has_irreducible_loop(true); // conservative until build_loop_tree() reset it
 691 
 692   if (ProfileTraps RTM_OPT_ONLY( || UseRTMLocking )) {
 693     // Make sure the method being compiled gets its own MDO,
 694     // so we can at least track the decompile_count().
 695     // Need MDO to record RTM code generation state.
 696     method()->ensure_method_data();
 697   }
 698 
 699   Init(/*do_aliasing=*/ true);
 700 
 701   print_compile_messages();
 702 
 703   _ilt = InlineTree::build_inline_tree_root();
 704 
 705   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
 706   assert(num_alias_types() >= AliasIdxRaw, "");
 707 
 708 #define MINIMUM_NODE_HASH  1023
 709 
 710   // GVN that will be run immediately on new nodes
 711   uint estimated_size = method()->code_size()*4+64;
 712   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
 713   _igvn_worklist = new (comp_arena()) Unique_Node_List(comp_arena());
 714   _types = new (comp_arena()) Type_Array(comp_arena());
 715   _node_hash = new (comp_arena()) NodeHash(comp_arena(), estimated_size);
 716   PhaseGVN gvn;
 717   set_initial_gvn(&gvn);
 718 
 719   print_inlining_init();
 720   { // Scope for timing the parser
 721     TracePhase tp("parse", &timers[_t_parser]);
 722 
 723     // Put top into the hash table ASAP.
 724     initial_gvn()->transform_no_reclaim(top());
 725 
 726     // Set up tf(), start(), and find a CallGenerator.
 727     CallGenerator* cg = nullptr;
 728     if (is_osr_compilation()) {
 729       const TypeTuple *domain = StartOSRNode::osr_domain();
 730       const TypeTuple *range = TypeTuple::make_range(method()->signature());
 731       init_tf(TypeFunc::make(domain, range));
 732       StartNode* s = new StartOSRNode(root(), domain);
 733       initial_gvn()->set_type_bottom(s);
 734       init_start(s);
 735       cg = CallGenerator::for_osr(method(), entry_bci());
 736     } else {
 737       // Normal case.
 738       init_tf(TypeFunc::make(method()));
 739       StartNode* s = new StartNode(root(), tf()->domain());
 740       initial_gvn()->set_type_bottom(s);
 741       init_start(s);
 742       if (method()->intrinsic_id() == vmIntrinsics::_Reference_get) {
 743         // With java.lang.ref.reference.get() we must go through the
 744         // intrinsic - even when get() is the root
 745         // method of the compile - so that, if necessary, the value in
 746         // the referent field of the reference object gets recorded by
 747         // the pre-barrier code.
 748         cg = find_intrinsic(method(), false);
 749       }
 750       if (cg == nullptr) {
 751         float past_uses = method()->interpreter_invocation_count();
 752         float expected_uses = past_uses;
 753         cg = CallGenerator::for_inline(method(), expected_uses);
 754       }
 755     }
 756     if (failing())  return;
 757     if (cg == nullptr) {
 758       const char* reason = InlineTree::check_can_parse(method());
 759       assert(reason != nullptr, "expect reason for parse failure");
 760       stringStream ss;
 761       ss.print("cannot parse method: %s", reason);
 762       record_method_not_compilable(ss.as_string());
 763       return;
 764     }
 765 
 766     gvn.set_type(root(), root()->bottom_type());
 767 
 768     JVMState* jvms = build_start_state(start(), tf());
 769     if ((jvms = cg->generate(jvms)) == nullptr) {
 770       if (!failure_reason_is(C2Compiler::retry_class_loading_during_parsing())) {
 771         assert(failure_reason() != nullptr, "expect reason for parse failure");
 772         stringStream ss;
 773         ss.print("method parse failed: %s", failure_reason());
 774         record_method_not_compilable(ss.as_string());
 775       }
 776       return;
 777     }
 778     GraphKit kit(jvms);
 779 
 780     if (!kit.stopped()) {
 781       // Accept return values, and transfer control we know not where.
 782       // This is done by a special, unique ReturnNode bound to root.
 783       return_values(kit.jvms());
 784     }
 785 
 786     if (kit.has_exceptions()) {
 787       // Any exceptions that escape from this call must be rethrown
 788       // to whatever caller is dynamically above us on the stack.
 789       // This is done by a special, unique RethrowNode bound to root.
 790       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
 791     }
 792 
 793     assert(IncrementalInline || (_late_inlines.length() == 0 && !has_mh_late_inlines()), "incremental inlining is off");
 794 
 795     if (_late_inlines.length() == 0 && !has_mh_late_inlines() && !failing() && has_stringbuilder()) {
 796       inline_string_calls(true);
 797     }
 798 
 799     if (failing())  return;
 800 
 801     print_method(PHASE_BEFORE_REMOVEUSELESS, 3);
 802 
 803     // Remove clutter produced by parsing.
 804     if (!failing()) {
 805       ResourceMark rm;
 806       PhaseRemoveUseless pru(initial_gvn(), *igvn_worklist());
 807     }
 808   }
 809 
 810   // Note:  Large methods are capped off in do_one_bytecode().
 811   if (failing())  return;
 812 
 813   // After parsing, node notes are no longer automagic.
 814   // They must be propagated by register_new_node_with_optimizer(),
 815   // clone(), or the like.
 816   set_default_node_notes(nullptr);
 817 
 818 #ifndef PRODUCT
 819   if (should_print_igv(1)) {
 820     _igv_printer->print_inlining();
 821   }
 822 #endif
 823 
 824   if (failing())  return;
 825   NOT_PRODUCT( verify_graph_edges(); )
 826 
 827   // If any phase is randomized for stress testing, seed random number
 828   // generation and log the seed for repeatability.
 829   if (StressLCM || StressGCM || StressIGVN || StressCCP) {
 830     if (FLAG_IS_DEFAULT(StressSeed) || (FLAG_IS_ERGO(StressSeed) && RepeatCompilation)) {
 831       _stress_seed = static_cast<uint>(Ticks::now().nanoseconds());
 832       FLAG_SET_ERGO(StressSeed, _stress_seed);
 833     } else {
 834       _stress_seed = StressSeed;
 835     }
 836     if (_log != nullptr) {
 837       _log->elem("stress_test seed='%u'", _stress_seed);
 838     }
 839   }
 840 
 841   // Now optimize
 842   Optimize();
 843   if (failing())  return;
 844   NOT_PRODUCT( verify_graph_edges(); )
 845 
 846 #ifndef PRODUCT
 847   if (should_print_ideal()) {
 848     print_ideal_ir("print_ideal");
 849   }
 850 #endif
 851 
 852 #ifdef ASSERT
 853   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 854   bs->verify_gc_barriers(this, BarrierSetC2::BeforeCodeGen);
 855 #endif
 856 
 857   // Dump compilation data to replay it.
 858   if (directive->DumpReplayOption) {
 859     env()->dump_replay_data(_compile_id);
 860   }
 861   if (directive->DumpInlineOption && (ilt() != nullptr)) {
 862     env()->dump_inline_data(_compile_id);
 863   }
 864 
 865   // Now that we know the size of all the monitors we can add a fixed slot
 866   // for the original deopt pc.
 867   int next_slot = fixed_slots() + (sizeof(address) / VMRegImpl::stack_slot_size);
 868   set_fixed_slots(next_slot);
 869 
 870   // Compute when to use implicit null checks. Used by matching trap based
 871   // nodes and NullCheck optimization.
 872   set_allowed_deopt_reasons();
 873 
 874   // Now generate code
 875   Code_Gen();
 876 }
 877 
 878 //------------------------------Compile----------------------------------------
 879 // Compile a runtime stub
 880 Compile::Compile( ciEnv* ci_env,
 881                   TypeFunc_generator generator,
 882                   address stub_function,
 883                   const char *stub_name,
 884                   int is_fancy_jump,
 885                   bool pass_tls,
 886                   bool return_pc,
 887                   DirectiveSet* directive)
 888   : Phase(Compiler),
 889     _compile_id(0),
 890     _options(Options::for_runtime_stub()),
 891     _method(nullptr),
 892     _entry_bci(InvocationEntryBci),
 893     _stub_function(stub_function),
 894     _stub_name(stub_name),
 895     _stub_entry_point(nullptr),
 896     _max_node_limit(MaxNodeLimit),
 897     _post_loop_opts_phase(false),
 898     _inlining_progress(false),
 899     _inlining_incrementally(false),
 900     _has_reserved_stack_access(false),
 901 #ifndef PRODUCT
 902     _igv_idx(0),
 903     _trace_opto_output(directive->TraceOptoOutputOption),
 904 #endif
 905     _has_method_handle_invokes(false),
 906     _clinit_barrier_on_entry(false),
 907     _stress_seed(0),
 908     _comp_arena(mtCompiler),
 909     _barrier_set_state(BarrierSet::barrier_set()->barrier_set_c2()->create_barrier_state(comp_arena())),
 910     _env(ci_env),
 911     _directive(directive),
 912     _log(ci_env->log()),
 913     _failure_reason(nullptr),
 914     _congraph(nullptr),
 915     NOT_PRODUCT(_igv_printer(nullptr) COMMA)
 916     _dead_node_list(comp_arena()),
 917     _dead_node_count(0),
 918     _node_arena(mtCompiler),
 919     _old_arena(mtCompiler),
 920     _mach_constant_base_node(nullptr),
 921     _Compile_types(mtCompiler),
 922     _initial_gvn(nullptr),
 923     _igvn_worklist(nullptr),
 924     _types(nullptr),
 925     _node_hash(nullptr),
 926     _number_of_mh_late_inlines(0),
 927     _print_inlining_stream(new (mtCompiler) stringStream()),
 928     _print_inlining_list(nullptr),
 929     _print_inlining_idx(0),
 930     _print_inlining_output(nullptr),
 931     _replay_inline_data(nullptr),
 932     _java_calls(0),
 933     _inner_loops(0),
 934     _interpreter_frame_size(0),
 935     _output(nullptr),
 936 #ifndef PRODUCT
 937     _in_dump_cnt(0),
 938 #endif
 939     _allowed_reasons(0) {
 940   C = this;
 941 
 942   TraceTime t1(nullptr, &_t_totalCompilation, CITime, false);
 943   TraceTime t2(nullptr, &_t_stubCompilation, CITime, false);
 944 
 945 #ifndef PRODUCT
 946   set_print_assembly(PrintFrameConverterAssembly);
 947   set_parsed_irreducible_loop(false);
 948 #else
 949   set_print_assembly(false); // Must initialize.
 950 #endif
 951   set_has_irreducible_loop(false); // no loops
 952 
 953   CompileWrapper cw(this);
 954   Init(/*do_aliasing=*/ false);
 955   init_tf((*generator)());
 956 
 957   _igvn_worklist = new (comp_arena()) Unique_Node_List(comp_arena());
 958   _types = new (comp_arena()) Type_Array(comp_arena());
 959   _node_hash = new (comp_arena()) NodeHash(comp_arena(), 255);
 960   {
 961     PhaseGVN gvn;
 962     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
 963     gvn.transform_no_reclaim(top());
 964 
 965     GraphKit kit;
 966     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
 967   }
 968 
 969   NOT_PRODUCT( verify_graph_edges(); )
 970 
 971   Code_Gen();
 972 }
 973 
 974 //------------------------------Init-------------------------------------------
 975 // Prepare for a single compilation
 976 void Compile::Init(bool aliasing) {
 977   _do_aliasing = aliasing;
 978   _unique  = 0;
 979   _regalloc = nullptr;
 980 
 981   _tf      = nullptr;  // filled in later
 982   _top     = nullptr;  // cached later
 983   _matcher = nullptr;  // filled in later
 984   _cfg     = nullptr;  // filled in later
 985 
 986   IA32_ONLY( set_24_bit_selection_and_mode(true, false); )
 987 
 988   _node_note_array = nullptr;
 989   _default_node_notes = nullptr;
 990   DEBUG_ONLY( _modified_nodes = nullptr; ) // Used in Optimize()
 991 
 992   _immutable_memory = nullptr; // filled in at first inquiry
 993 
 994 #ifdef ASSERT
 995   _phase_optimize_finished = false;
 996   _exception_backedge = false;
 997   _type_verify = nullptr;
 998 #endif
 999 
1000   // Globally visible Nodes
1001   // First set TOP to null to give safe behavior during creation of RootNode
1002   set_cached_top_node(nullptr);
1003   set_root(new RootNode());
1004   // Now that you have a Root to point to, create the real TOP
1005   set_cached_top_node( new ConNode(Type::TOP) );
1006   set_recent_alloc(nullptr, nullptr);
1007 
1008   // Create Debug Information Recorder to record scopes, oopmaps, etc.
1009   env()->set_oop_recorder(new OopRecorder(env()->arena()));
1010   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
1011   env()->set_dependencies(new Dependencies(env()));
1012 
1013   _fixed_slots = 0;
1014   set_has_split_ifs(false);
1015   set_has_loops(false); // first approximation
1016   set_has_stringbuilder(false);
1017   set_has_boxed_value(false);
1018   _trap_can_recompile = false;  // no traps emitted yet
1019   _major_progress = true; // start out assuming good things will happen
1020   set_has_unsafe_access(false);
1021   set_max_vector_size(0);
1022   set_clear_upper_avx(false);  //false as default for clear upper bits of ymm registers
1023   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
1024   set_decompile_count(0);
1025 
1026   set_do_freq_based_layout(_directive->BlockLayoutByFrequencyOption);
1027   _loop_opts_cnt = LoopOptsCount;
1028   set_do_inlining(Inline);
1029   set_max_inline_size(MaxInlineSize);
1030   set_freq_inline_size(FreqInlineSize);
1031   set_do_scheduling(OptoScheduling);
1032 
1033   set_do_vector_loop(false);
1034   set_has_monitors(false);
1035 
1036   if (AllowVectorizeOnDemand) {
1037     if (has_method() && (_directive->VectorizeOption || _directive->VectorizeDebugOption)) {
1038       set_do_vector_loop(true);
1039       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());})
1040     } else if (has_method() && method()->name() != 0 &&
1041                method()->intrinsic_id() == vmIntrinsics::_forEachRemaining) {
1042       set_do_vector_loop(true);
1043     }
1044   }
1045   set_use_cmove(UseCMoveUnconditionally /* || do_vector_loop()*/); //TODO: consider do_vector_loop() mandate use_cmove unconditionally
1046   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());})
1047 
1048   set_rtm_state(NoRTM); // No RTM lock eliding by default
1049   _max_node_limit = _directive->MaxNodeLimitOption;
1050 
1051 #if INCLUDE_RTM_OPT
1052   if (UseRTMLocking && has_method() && (method()->method_data_or_null() != nullptr)) {
1053     int rtm_state = method()->method_data()->rtm_state();
1054     if (method_has_option(CompileCommand::NoRTMLockEliding) || ((rtm_state & NoRTM) != 0)) {
1055       // Don't generate RTM lock eliding code.
1056       set_rtm_state(NoRTM);
1057     } else if (method_has_option(CompileCommand::UseRTMLockEliding) || ((rtm_state & UseRTM) != 0) || !UseRTMDeopt) {
1058       // Generate RTM lock eliding code without abort ratio calculation code.
1059       set_rtm_state(UseRTM);
1060     } else if (UseRTMDeopt) {
1061       // Generate RTM lock eliding code and include abort ratio calculation
1062       // code if UseRTMDeopt is on.
1063       set_rtm_state(ProfileRTM);
1064     }
1065   }
1066 #endif
1067   if (VM_Version::supports_fast_class_init_checks() && has_method() && !is_osr_compilation() && method()->needs_clinit_barrier()) {
1068     set_clinit_barrier_on_entry(true);
1069   }
1070   if (debug_info()->recording_non_safepoints()) {
1071     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
1072                         (comp_arena(), 8, 0, nullptr));
1073     set_default_node_notes(Node_Notes::make(this));
1074   }
1075 
1076   const int grow_ats = 16;
1077   _max_alias_types = grow_ats;
1078   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
1079   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
1080   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
1081   {
1082     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
1083   }
1084   // Initialize the first few types.
1085   _alias_types[AliasIdxTop]->Init(AliasIdxTop, nullptr);
1086   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
1087   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
1088   _num_alias_types = AliasIdxRaw+1;
1089   // Zero out the alias type cache.
1090   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
1091   // A null adr_type hits in the cache right away.  Preload the right answer.
1092   probe_alias_cache(nullptr)->_index = AliasIdxTop;
1093 }
1094 
1095 //---------------------------init_start----------------------------------------
1096 // Install the StartNode on this compile object.
1097 void Compile::init_start(StartNode* s) {
1098   if (failing())
1099     return; // already failing
1100   assert(s == start(), "");
1101 }
1102 
1103 /**
1104  * Return the 'StartNode'. We must not have a pending failure, since the ideal graph
1105  * can be in an inconsistent state, i.e., we can get segmentation faults when traversing
1106  * the ideal graph.
1107  */
1108 StartNode* Compile::start() const {
1109   assert (!failing(), "Must not have pending failure. Reason is: %s", failure_reason());
1110   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
1111     Node* start = root()->fast_out(i);
1112     if (start->is_Start()) {
1113       return start->as_Start();
1114     }
1115   }
1116   fatal("Did not find Start node!");
1117   return nullptr;
1118 }
1119 
1120 //-------------------------------immutable_memory-------------------------------------
1121 // Access immutable memory
1122 Node* Compile::immutable_memory() {
1123   if (_immutable_memory != nullptr) {
1124     return _immutable_memory;
1125   }
1126   StartNode* s = start();
1127   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
1128     Node *p = s->fast_out(i);
1129     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
1130       _immutable_memory = p;
1131       return _immutable_memory;
1132     }
1133   }
1134   ShouldNotReachHere();
1135   return nullptr;
1136 }
1137 
1138 //----------------------set_cached_top_node------------------------------------
1139 // Install the cached top node, and make sure Node::is_top works correctly.
1140 void Compile::set_cached_top_node(Node* tn) {
1141   if (tn != nullptr)  verify_top(tn);
1142   Node* old_top = _top;
1143   _top = tn;
1144   // Calling Node::setup_is_top allows the nodes the chance to adjust
1145   // their _out arrays.
1146   if (_top != nullptr)     _top->setup_is_top();
1147   if (old_top != nullptr)  old_top->setup_is_top();
1148   assert(_top == nullptr || top()->is_top(), "");
1149 }
1150 
1151 #ifdef ASSERT
1152 uint Compile::count_live_nodes_by_graph_walk() {
1153   Unique_Node_List useful(comp_arena());
1154   // Get useful node list by walking the graph.
1155   identify_useful_nodes(useful);
1156   return useful.size();
1157 }
1158 
1159 void Compile::print_missing_nodes() {
1160 
1161   // Return if CompileLog is null and PrintIdealNodeCount is false.
1162   if ((_log == nullptr) && (! PrintIdealNodeCount)) {
1163     return;
1164   }
1165 
1166   // This is an expensive function. It is executed only when the user
1167   // specifies VerifyIdealNodeCount option or otherwise knows the
1168   // additional work that needs to be done to identify reachable nodes
1169   // by walking the flow graph and find the missing ones using
1170   // _dead_node_list.
1171 
1172   Unique_Node_List useful(comp_arena());
1173   // Get useful node list by walking the graph.
1174   identify_useful_nodes(useful);
1175 
1176   uint l_nodes = C->live_nodes();
1177   uint l_nodes_by_walk = useful.size();
1178 
1179   if (l_nodes != l_nodes_by_walk) {
1180     if (_log != nullptr) {
1181       _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
1182       _log->stamp();
1183       _log->end_head();
1184     }
1185     VectorSet& useful_member_set = useful.member_set();
1186     int last_idx = l_nodes_by_walk;
1187     for (int i = 0; i < last_idx; i++) {
1188       if (useful_member_set.test(i)) {
1189         if (_dead_node_list.test(i)) {
1190           if (_log != nullptr) {
1191             _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
1192           }
1193           if (PrintIdealNodeCount) {
1194             // Print the log message to tty
1195               tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
1196               useful.at(i)->dump();
1197           }
1198         }
1199       }
1200       else if (! _dead_node_list.test(i)) {
1201         if (_log != nullptr) {
1202           _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
1203         }
1204         if (PrintIdealNodeCount) {
1205           // Print the log message to tty
1206           tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
1207         }
1208       }
1209     }
1210     if (_log != nullptr) {
1211       _log->tail("mismatched_nodes");
1212     }
1213   }
1214 }
1215 void Compile::record_modified_node(Node* n) {
1216   if (_modified_nodes != nullptr && !_inlining_incrementally && !n->is_Con()) {
1217     _modified_nodes->push(n);
1218   }
1219 }
1220 
1221 void Compile::remove_modified_node(Node* n) {
1222   if (_modified_nodes != nullptr) {
1223     _modified_nodes->remove(n);
1224   }
1225 }
1226 #endif
1227 
1228 #ifndef PRODUCT
1229 void Compile::verify_top(Node* tn) const {
1230   if (tn != nullptr) {
1231     assert(tn->is_Con(), "top node must be a constant");
1232     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
1233     assert(tn->in(0) != nullptr, "must have live top node");
1234   }
1235 }
1236 #endif
1237 
1238 
1239 ///-------------------Managing Per-Node Debug & Profile Info-------------------
1240 
1241 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
1242   guarantee(arr != nullptr, "");
1243   int num_blocks = arr->length();
1244   if (grow_by < num_blocks)  grow_by = num_blocks;
1245   int num_notes = grow_by * _node_notes_block_size;
1246   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
1247   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
1248   while (num_notes > 0) {
1249     arr->append(notes);
1250     notes     += _node_notes_block_size;
1251     num_notes -= _node_notes_block_size;
1252   }
1253   assert(num_notes == 0, "exact multiple, please");
1254 }
1255 
1256 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
1257   if (source == nullptr || dest == nullptr)  return false;
1258 
1259   if (dest->is_Con())
1260     return false;               // Do not push debug info onto constants.
1261 
1262 #ifdef ASSERT
1263   // Leave a bread crumb trail pointing to the original node:
1264   if (dest != nullptr && dest != source && dest->debug_orig() == nullptr) {
1265     dest->set_debug_orig(source);
1266   }
1267 #endif
1268 
1269   if (node_note_array() == nullptr)
1270     return false;               // Not collecting any notes now.
1271 
1272   // This is a copy onto a pre-existing node, which may already have notes.
1273   // If both nodes have notes, do not overwrite any pre-existing notes.
1274   Node_Notes* source_notes = node_notes_at(source->_idx);
1275   if (source_notes == nullptr || source_notes->is_clear())  return false;
1276   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
1277   if (dest_notes == nullptr || dest_notes->is_clear()) {
1278     return set_node_notes_at(dest->_idx, source_notes);
1279   }
1280 
1281   Node_Notes merged_notes = (*source_notes);
1282   // The order of operations here ensures that dest notes will win...
1283   merged_notes.update_from(dest_notes);
1284   return set_node_notes_at(dest->_idx, &merged_notes);
1285 }
1286 
1287 
1288 //--------------------------allow_range_check_smearing-------------------------
1289 // Gating condition for coalescing similar range checks.
1290 // Sometimes we try 'speculatively' replacing a series of a range checks by a
1291 // single covering check that is at least as strong as any of them.
1292 // If the optimization succeeds, the simplified (strengthened) range check
1293 // will always succeed.  If it fails, we will deopt, and then give up
1294 // on the optimization.
1295 bool Compile::allow_range_check_smearing() const {
1296   // If this method has already thrown a range-check,
1297   // assume it was because we already tried range smearing
1298   // and it failed.
1299   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
1300   return !already_trapped;
1301 }
1302 
1303 
1304 //------------------------------flatten_alias_type-----------------------------
1305 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
1306   assert(do_aliasing(), "Aliasing should be enabled");
1307   int offset = tj->offset();
1308   TypePtr::PTR ptr = tj->ptr();
1309 
1310   // Known instance (scalarizable allocation) alias only with itself.
1311   bool is_known_inst = tj->isa_oopptr() != nullptr &&
1312                        tj->is_oopptr()->is_known_instance();
1313 
1314   // Process weird unsafe references.
1315   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1316     assert(InlineUnsafeOps || StressReflectiveCode, "indeterminate pointers come only from unsafe ops");
1317     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
1318     tj = TypeOopPtr::BOTTOM;
1319     ptr = tj->ptr();
1320     offset = tj->offset();
1321   }
1322 
1323   // Array pointers need some flattening
1324   const TypeAryPtr* ta = tj->isa_aryptr();
1325   if (ta && ta->is_stable()) {
1326     // Erase stability property for alias analysis.
1327     tj = ta = ta->cast_to_stable(false);
1328   }
1329   if( ta && is_known_inst ) {
1330     if ( offset != Type::OffsetBot &&
1331          offset > arrayOopDesc::length_offset_in_bytes() ) {
1332       offset = Type::OffsetBot; // Flatten constant access into array body only
1333       tj = ta = ta->
1334               remove_speculative()->
1335               cast_to_ptr_type(ptr)->
1336               with_offset(offset);
1337     }
1338   } else if (ta) {
1339     // For arrays indexed by constant indices, we flatten the alias
1340     // space to include all of the array body.  Only the header, klass
1341     // and array length can be accessed un-aliased.
1342     if( offset != Type::OffsetBot ) {
1343       if( ta->const_oop() ) { // MethodData* or Method*
1344         offset = Type::OffsetBot;   // Flatten constant access into array body
1345         tj = ta = ta->
1346                 remove_speculative()->
1347                 cast_to_ptr_type(ptr)->
1348                 cast_to_exactness(false)->
1349                 with_offset(offset);
1350       } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
1351         // range is OK as-is.
1352         tj = ta = TypeAryPtr::RANGE;
1353       } else if( offset == oopDesc::klass_offset_in_bytes() ) {
1354         tj = TypeInstPtr::KLASS; // all klass loads look alike
1355         ta = TypeAryPtr::RANGE; // generic ignored junk
1356         ptr = TypePtr::BotPTR;
1357       } else if( offset == oopDesc::mark_offset_in_bytes() ) {
1358         tj = TypeInstPtr::MARK;
1359         ta = TypeAryPtr::RANGE; // generic ignored junk
1360         ptr = TypePtr::BotPTR;
1361       } else {                  // Random constant offset into array body
1362         offset = Type::OffsetBot;   // Flatten constant access into array body
1363         tj = ta = ta->
1364                 remove_speculative()->
1365                 cast_to_ptr_type(ptr)->
1366                 cast_to_exactness(false)->
1367                 with_offset(offset);
1368       }
1369     }
1370     // Arrays of fixed size alias with arrays of unknown size.
1371     if (ta->size() != TypeInt::POS) {
1372       const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
1373       tj = ta = ta->
1374               remove_speculative()->
1375               cast_to_ptr_type(ptr)->
1376               with_ary(tary)->
1377               cast_to_exactness(false);
1378     }
1379     // Arrays of known objects become arrays of unknown objects.
1380     if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
1381       const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
1382       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,nullptr,false,offset);
1383     }
1384     if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
1385       const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
1386       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,nullptr,false,offset);
1387     }
1388     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
1389     // cannot be distinguished by bytecode alone.
1390     if (ta->elem() == TypeInt::BOOL) {
1391       const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
1392       ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
1393       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,offset);
1394     }
1395     // During the 2nd round of IterGVN, NotNull castings are removed.
1396     // Make sure the Bottom and NotNull variants alias the same.
1397     // Also, make sure exact and non-exact variants alias the same.
1398     if (ptr == TypePtr::NotNull || ta->klass_is_exact() || ta->speculative() != nullptr) {
1399       tj = ta = ta->
1400               remove_speculative()->
1401               cast_to_ptr_type(TypePtr::BotPTR)->
1402               cast_to_exactness(false)->
1403               with_offset(offset);
1404     }
1405   }
1406 
1407   // Oop pointers need some flattening
1408   const TypeInstPtr *to = tj->isa_instptr();
1409   if (to && to != TypeOopPtr::BOTTOM) {
1410     ciInstanceKlass* ik = to->instance_klass();
1411     if( ptr == TypePtr::Constant ) {
1412       if (ik != ciEnv::current()->Class_klass() ||
1413           offset < ik->layout_helper_size_in_bytes()) {
1414         // No constant oop pointers (such as Strings); they alias with
1415         // unknown strings.
1416         assert(!is_known_inst, "not scalarizable allocation");
1417         tj = to = to->
1418                 cast_to_instance_id(TypeOopPtr::InstanceBot)->
1419                 remove_speculative()->
1420                 cast_to_ptr_type(TypePtr::BotPTR)->
1421                 cast_to_exactness(false);
1422       }
1423     } else if( is_known_inst ) {
1424       tj = to; // Keep NotNull and klass_is_exact for instance type
1425     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1426       // During the 2nd round of IterGVN, NotNull castings are removed.
1427       // Make sure the Bottom and NotNull variants alias the same.
1428       // Also, make sure exact and non-exact variants alias the same.
1429       tj = to = to->
1430               remove_speculative()->
1431               cast_to_instance_id(TypeOopPtr::InstanceBot)->
1432               cast_to_ptr_type(TypePtr::BotPTR)->
1433               cast_to_exactness(false);
1434     }
1435     if (to->speculative() != nullptr) {
1436       tj = to = to->remove_speculative();
1437     }
1438     // Canonicalize the holder of this field
1439     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1440       // First handle header references such as a LoadKlassNode, even if the
1441       // object's klass is unloaded at compile time (4965979).
1442       if (!is_known_inst) { // Do it only for non-instance types
1443         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, nullptr, offset);
1444       }
1445     } else if (offset < 0 || offset >= ik->layout_helper_size_in_bytes()) {
1446       // Static fields are in the space above the normal instance
1447       // fields in the java.lang.Class instance.
1448       if (ik != ciEnv::current()->Class_klass()) {
1449         to = nullptr;
1450         tj = TypeOopPtr::BOTTOM;
1451         offset = tj->offset();
1452       }
1453     } else {
1454       ciInstanceKlass *canonical_holder = ik->get_canonical_holder(offset);
1455       assert(offset < canonical_holder->layout_helper_size_in_bytes(), "");
1456       if (!ik->equals(canonical_holder) || tj->offset() != offset) {
1457         if( is_known_inst ) {
1458           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, true, nullptr, offset, to->instance_id());
1459         } else {
1460           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, nullptr, offset);
1461         }
1462       }
1463     }
1464   }
1465 
1466   // Klass pointers to object array klasses need some flattening
1467   const TypeKlassPtr *tk = tj->isa_klassptr();
1468   if( tk ) {
1469     // If we are referencing a field within a Klass, we need
1470     // to assume the worst case of an Object.  Both exact and
1471     // inexact types must flatten to the same alias class so
1472     // use NotNull as the PTR.
1473     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1474       tj = tk = TypeInstKlassPtr::make(TypePtr::NotNull,
1475                                        env()->Object_klass(),
1476                                        offset);
1477     }
1478 
1479     if (tk->isa_aryklassptr() && tk->is_aryklassptr()->elem()->isa_klassptr()) {
1480       ciKlass* k = ciObjArrayKlass::make(env()->Object_klass());
1481       if (!k || !k->is_loaded()) {                  // Only fails for some -Xcomp runs
1482         tj = tk = TypeInstKlassPtr::make(TypePtr::NotNull, env()->Object_klass(), offset);
1483       } else {
1484         tj = tk = TypeAryKlassPtr::make(TypePtr::NotNull, tk->is_aryklassptr()->elem(), k, offset);
1485       }
1486     }
1487 
1488     // Check for precise loads from the primary supertype array and force them
1489     // to the supertype cache alias index.  Check for generic array loads from
1490     // the primary supertype array and also force them to the supertype cache
1491     // alias index.  Since the same load can reach both, we need to merge
1492     // these 2 disparate memories into the same alias class.  Since the
1493     // primary supertype array is read-only, there's no chance of confusion
1494     // where we bypass an array load and an array store.
1495     int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
1496     if (offset == Type::OffsetBot ||
1497         (offset >= primary_supers_offset &&
1498          offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
1499         offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
1500       offset = in_bytes(Klass::secondary_super_cache_offset());
1501       tj = tk = tk->with_offset(offset);
1502     }
1503   }
1504 
1505   // Flatten all Raw pointers together.
1506   if (tj->base() == Type::RawPtr)
1507     tj = TypeRawPtr::BOTTOM;
1508 
1509   if (tj->base() == Type::AnyPtr)
1510     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
1511 
1512   offset = tj->offset();
1513   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
1514 
1515   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
1516           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
1517           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
1518           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
1519           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1520           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1521           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr),
1522           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
1523   assert( tj->ptr() != TypePtr::TopPTR &&
1524           tj->ptr() != TypePtr::AnyNull &&
1525           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
1526 //    assert( tj->ptr() != TypePtr::Constant ||
1527 //            tj->base() == Type::RawPtr ||
1528 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
1529 
1530   return tj;
1531 }
1532 
1533 void Compile::AliasType::Init(int i, const TypePtr* at) {
1534   assert(AliasIdxTop <= i && i < Compile::current()->_max_alias_types, "Invalid alias index");
1535   _index = i;
1536   _adr_type = at;
1537   _field = nullptr;
1538   _element = nullptr;
1539   _is_rewritable = true; // default
1540   const TypeOopPtr *atoop = (at != nullptr) ? at->isa_oopptr() : nullptr;
1541   if (atoop != nullptr && atoop->is_known_instance()) {
1542     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
1543     _general_index = Compile::current()->get_alias_index(gt);
1544   } else {
1545     _general_index = 0;
1546   }
1547 }
1548 
1549 BasicType Compile::AliasType::basic_type() const {
1550   if (element() != nullptr) {
1551     const Type* element = adr_type()->is_aryptr()->elem();
1552     return element->isa_narrowoop() ? T_OBJECT : element->array_element_basic_type();
1553   } if (field() != nullptr) {
1554     return field()->layout_type();
1555   } else {
1556     return T_ILLEGAL; // unknown
1557   }
1558 }
1559 
1560 //---------------------------------print_on------------------------------------
1561 #ifndef PRODUCT
1562 void Compile::AliasType::print_on(outputStream* st) {
1563   if (index() < 10)
1564         st->print("@ <%d> ", index());
1565   else  st->print("@ <%d>",  index());
1566   st->print(is_rewritable() ? "   " : " RO");
1567   int offset = adr_type()->offset();
1568   if (offset == Type::OffsetBot)
1569         st->print(" +any");
1570   else  st->print(" +%-3d", offset);
1571   st->print(" in ");
1572   adr_type()->dump_on(st);
1573   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
1574   if (field() != nullptr && tjp) {
1575     if (tjp->is_instptr()->instance_klass()  != field()->holder() ||
1576         tjp->offset() != field()->offset_in_bytes()) {
1577       st->print(" != ");
1578       field()->print();
1579       st->print(" ***");
1580     }
1581   }
1582 }
1583 
1584 void print_alias_types() {
1585   Compile* C = Compile::current();
1586   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
1587   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
1588     C->alias_type(idx)->print_on(tty);
1589     tty->cr();
1590   }
1591 }
1592 #endif
1593 
1594 
1595 //----------------------------probe_alias_cache--------------------------------
1596 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
1597   intptr_t key = (intptr_t) adr_type;
1598   key ^= key >> logAliasCacheSize;
1599   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1600 }
1601 
1602 
1603 //-----------------------------grow_alias_types--------------------------------
1604 void Compile::grow_alias_types() {
1605   const int old_ats  = _max_alias_types; // how many before?
1606   const int new_ats  = old_ats;          // how many more?
1607   const int grow_ats = old_ats+new_ats;  // how many now?
1608   _max_alias_types = grow_ats;
1609   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
1610   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1611   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1612   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
1613 }
1614 
1615 
1616 //--------------------------------find_alias_type------------------------------
1617 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field) {
1618   if (!do_aliasing()) {
1619     return alias_type(AliasIdxBot);
1620   }
1621 
1622   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1623   if (ace->_adr_type == adr_type) {
1624     return alias_type(ace->_index);
1625   }
1626 
1627   // Handle special cases.
1628   if (adr_type == nullptr)          return alias_type(AliasIdxTop);
1629   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
1630 
1631   // Do it the slow way.
1632   const TypePtr* flat = flatten_alias_type(adr_type);
1633 
1634 #ifdef ASSERT
1635   {
1636     ResourceMark rm;
1637     assert(flat == flatten_alias_type(flat), "not idempotent: adr_type = %s; flat = %s => %s",
1638            Type::str(adr_type), Type::str(flat), Type::str(flatten_alias_type(flat)));
1639     assert(flat != TypePtr::BOTTOM, "cannot alias-analyze an untyped ptr: adr_type = %s",
1640            Type::str(adr_type));
1641     if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1642       const TypeOopPtr* foop = flat->is_oopptr();
1643       // Scalarizable allocations have exact klass always.
1644       bool exact = !foop->klass_is_exact() || foop->is_known_instance();
1645       const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
1646       assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type: foop = %s; xoop = %s",
1647              Type::str(foop), Type::str(xoop));
1648     }
1649   }
1650 #endif
1651 
1652   int idx = AliasIdxTop;
1653   for (int i = 0; i < num_alias_types(); i++) {
1654     if (alias_type(i)->adr_type() == flat) {
1655       idx = i;
1656       break;
1657     }
1658   }
1659 
1660   if (idx == AliasIdxTop) {
1661     if (no_create)  return nullptr;
1662     // Grow the array if necessary.
1663     if (_num_alias_types == _max_alias_types)  grow_alias_types();
1664     // Add a new alias type.
1665     idx = _num_alias_types++;
1666     _alias_types[idx]->Init(idx, flat);
1667     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
1668     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
1669     if (flat->isa_instptr()) {
1670       if (flat->offset() == java_lang_Class::klass_offset()
1671           && flat->is_instptr()->instance_klass() == env()->Class_klass())
1672         alias_type(idx)->set_rewritable(false);
1673     }
1674     if (flat->isa_aryptr()) {
1675 #ifdef ASSERT
1676       const int header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1677       // (T_BYTE has the weakest alignment and size restrictions...)
1678       assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
1679 #endif
1680       if (flat->offset() == TypePtr::OffsetBot) {
1681         alias_type(idx)->set_element(flat->is_aryptr()->elem());
1682       }
1683     }
1684     if (flat->isa_klassptr()) {
1685       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1686         alias_type(idx)->set_rewritable(false);
1687       if (flat->offset() == in_bytes(Klass::modifier_flags_offset()))
1688         alias_type(idx)->set_rewritable(false);
1689       if (flat->offset() == in_bytes(Klass::access_flags_offset()))
1690         alias_type(idx)->set_rewritable(false);
1691       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1692         alias_type(idx)->set_rewritable(false);
1693       if (flat->offset() == in_bytes(Klass::secondary_super_cache_offset()))
1694         alias_type(idx)->set_rewritable(false);
1695     }
1696     // %%% (We would like to finalize JavaThread::threadObj_offset(),
1697     // but the base pointer type is not distinctive enough to identify
1698     // references into JavaThread.)
1699 
1700     // Check for final fields.
1701     const TypeInstPtr* tinst = flat->isa_instptr();
1702     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1703       ciField* field;
1704       if (tinst->const_oop() != nullptr &&
1705           tinst->instance_klass() == ciEnv::current()->Class_klass() &&
1706           tinst->offset() >= (tinst->instance_klass()->layout_helper_size_in_bytes())) {
1707         // static field
1708         ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
1709         field = k->get_field_by_offset(tinst->offset(), true);
1710       } else {
1711         ciInstanceKlass *k = tinst->instance_klass();
1712         field = k->get_field_by_offset(tinst->offset(), false);
1713       }
1714       assert(field == nullptr ||
1715              original_field == nullptr ||
1716              (field->holder() == original_field->holder() &&
1717               field->offset_in_bytes() == original_field->offset_in_bytes() &&
1718               field->is_static() == original_field->is_static()), "wrong field?");
1719       // Set field() and is_rewritable() attributes.
1720       if (field != nullptr)  alias_type(idx)->set_field(field);
1721     }
1722   }
1723 
1724   // Fill the cache for next time.
1725   ace->_adr_type = adr_type;
1726   ace->_index    = idx;
1727   assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
1728 
1729   // Might as well try to fill the cache for the flattened version, too.
1730   AliasCacheEntry* face = probe_alias_cache(flat);
1731   if (face->_adr_type == nullptr) {
1732     face->_adr_type = flat;
1733     face->_index    = idx;
1734     assert(alias_type(flat) == alias_type(idx), "flat type must work too");
1735   }
1736 
1737   return alias_type(idx);
1738 }
1739 
1740 
1741 Compile::AliasType* Compile::alias_type(ciField* field) {
1742   const TypeOopPtr* t;
1743   if (field->is_static())
1744     t = TypeInstPtr::make(field->holder()->java_mirror());
1745   else
1746     t = TypeOopPtr::make_from_klass_raw(field->holder());
1747   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
1748   assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
1749   return atp;
1750 }
1751 
1752 
1753 //------------------------------have_alias_type--------------------------------
1754 bool Compile::have_alias_type(const TypePtr* adr_type) {
1755   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1756   if (ace->_adr_type == adr_type) {
1757     return true;
1758   }
1759 
1760   // Handle special cases.
1761   if (adr_type == nullptr)             return true;
1762   if (adr_type == TypePtr::BOTTOM)  return true;
1763 
1764   return find_alias_type(adr_type, true, nullptr) != nullptr;
1765 }
1766 
1767 //-----------------------------must_alias--------------------------------------
1768 // True if all values of the given address type are in the given alias category.
1769 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
1770   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1771   if (adr_type == nullptr)              return true;  // null serves as TypePtr::TOP
1772   if (alias_idx == AliasIdxTop)         return false; // the empty category
1773   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
1774 
1775   // the only remaining possible overlap is identity
1776   int adr_idx = get_alias_index(adr_type);
1777   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1778   assert(adr_idx == alias_idx ||
1779          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
1780           && adr_type                       != TypeOopPtr::BOTTOM),
1781          "should not be testing for overlap with an unsafe pointer");
1782   return adr_idx == alias_idx;
1783 }
1784 
1785 //------------------------------can_alias--------------------------------------
1786 // True if any values of the given address type are in the given alias category.
1787 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
1788   if (alias_idx == AliasIdxTop)         return false; // the empty category
1789   if (adr_type == nullptr)              return false; // null serves as TypePtr::TOP
1790   // Known instance doesn't alias with bottom memory
1791   if (alias_idx == AliasIdxBot)         return !adr_type->is_known_instance();                   // the universal category
1792   if (adr_type->base() == Type::AnyPtr) return !C->get_adr_type(alias_idx)->is_known_instance(); // TypePtr::BOTTOM or its twins
1793 
1794   // the only remaining possible overlap is identity
1795   int adr_idx = get_alias_index(adr_type);
1796   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1797   return adr_idx == alias_idx;
1798 }
1799 
1800 // Remove the opaque nodes that protect the Parse Predicates so that all unused
1801 // checks and uncommon_traps will be eliminated from the ideal graph.
1802 void Compile::cleanup_parse_predicates(PhaseIterGVN& igvn) const {
1803   if (parse_predicate_count() == 0) {
1804     return;
1805   }
1806   for (int i = parse_predicate_count(); i > 0; i--) {
1807     Node* n = parse_predicate_opaque1_node(i - 1);
1808     assert(n->Opcode() == Op_Opaque1, "must be");
1809     igvn.replace_node(n, n->in(1));
1810   }
1811   assert(parse_predicate_count() == 0, "should be clean!");
1812 }
1813 
1814 void Compile::record_for_post_loop_opts_igvn(Node* n) {
1815   if (!n->for_post_loop_opts_igvn()) {
1816     assert(!_for_post_loop_igvn.contains(n), "duplicate");
1817     n->add_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
1818     _for_post_loop_igvn.append(n);
1819   }
1820 }
1821 
1822 void Compile::remove_from_post_loop_opts_igvn(Node* n) {
1823   n->remove_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
1824   _for_post_loop_igvn.remove(n);
1825 }
1826 
1827 void Compile::process_for_post_loop_opts_igvn(PhaseIterGVN& igvn) {
1828   // Verify that all previous optimizations produced a valid graph
1829   // at least to this point, even if no loop optimizations were done.
1830   PhaseIdealLoop::verify(igvn);
1831 
1832   C->set_post_loop_opts_phase(); // no more loop opts allowed
1833 
1834   assert(!C->major_progress(), "not cleared");
1835 
1836   if (_for_post_loop_igvn.length() > 0) {
1837     while (_for_post_loop_igvn.length() > 0) {
1838       Node* n = _for_post_loop_igvn.pop();
1839       n->remove_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
1840       igvn._worklist.push(n);
1841     }
1842     igvn.optimize();
1843     assert(_for_post_loop_igvn.length() == 0, "no more delayed nodes allowed");
1844 
1845     // Sometimes IGVN sets major progress (e.g., when processing loop nodes).
1846     if (C->major_progress()) {
1847       C->clear_major_progress(); // ensure that major progress is now clear
1848     }
1849   }
1850 }
1851 
1852 void Compile::record_unstable_if_trap(UnstableIfTrap* trap) {
1853   if (OptimizeUnstableIf) {
1854     _unstable_if_traps.append(trap);
1855   }
1856 }
1857 
1858 void Compile::remove_useless_unstable_if_traps(Unique_Node_List& useful) {
1859   for (int i = _unstable_if_traps.length() - 1; i >= 0; i--) {
1860     UnstableIfTrap* trap = _unstable_if_traps.at(i);
1861     Node* n = trap->uncommon_trap();
1862     if (!useful.member(n)) {
1863       _unstable_if_traps.delete_at(i); // replaces i-th with last element which is known to be useful (already processed)
1864     }
1865   }
1866 }
1867 
1868 // Remove the unstable if trap associated with 'unc' from candidates. It is either dead
1869 // or fold-compares case. Return true if succeed or not found.
1870 //
1871 // In rare cases, the found trap has been processed. It is too late to delete it. Return
1872 // false and ask fold-compares to yield.
1873 //
1874 // 'fold-compares' may use the uncommon_trap of the dominating IfNode to cover the fused
1875 // IfNode. This breaks the unstable_if trap invariant: control takes the unstable path
1876 // when deoptimization does happen.
1877 bool Compile::remove_unstable_if_trap(CallStaticJavaNode* unc, bool yield) {
1878   for (int i = 0; i < _unstable_if_traps.length(); ++i) {
1879     UnstableIfTrap* trap = _unstable_if_traps.at(i);
1880     if (trap->uncommon_trap() == unc) {
1881       if (yield && trap->modified()) {
1882         return false;
1883       }
1884       _unstable_if_traps.delete_at(i);
1885       break;
1886     }
1887   }
1888   return true;
1889 }
1890 
1891 // Re-calculate unstable_if traps with the liveness of next_bci, which points to the unlikely path.
1892 // It needs to be done after igvn because fold-compares may fuse uncommon_traps and before renumbering.
1893 void Compile::process_for_unstable_if_traps(PhaseIterGVN& igvn) {
1894   for (int i = _unstable_if_traps.length() - 1; i >= 0; --i) {
1895     UnstableIfTrap* trap = _unstable_if_traps.at(i);
1896     CallStaticJavaNode* unc = trap->uncommon_trap();
1897     int next_bci = trap->next_bci();
1898     bool modified = trap->modified();
1899 
1900     if (next_bci != -1 && !modified) {
1901       assert(!_dead_node_list.test(unc->_idx), "changing a dead node!");
1902       JVMState* jvms = unc->jvms();
1903       ciMethod* method = jvms->method();
1904       ciBytecodeStream iter(method);
1905 
1906       iter.force_bci(jvms->bci());
1907       assert(next_bci == iter.next_bci() || next_bci == iter.get_dest(), "wrong next_bci at unstable_if");
1908       Bytecodes::Code c = iter.cur_bc();
1909       Node* lhs = nullptr;
1910       Node* rhs = nullptr;
1911       if (c == Bytecodes::_if_acmpeq || c == Bytecodes::_if_acmpne) {
1912         lhs = unc->peek_operand(0);
1913         rhs = unc->peek_operand(1);
1914       } else if (c == Bytecodes::_ifnull || c == Bytecodes::_ifnonnull) {
1915         lhs = unc->peek_operand(0);
1916       }
1917 
1918       ResourceMark rm;
1919       const MethodLivenessResult& live_locals = method->liveness_at_bci(next_bci);
1920       assert(live_locals.is_valid(), "broken liveness info");
1921       int len = (int)live_locals.size();
1922 
1923       for (int i = 0; i < len; i++) {
1924         Node* local = unc->local(jvms, i);
1925         // kill local using the liveness of next_bci.
1926         // give up when the local looks like an operand to secure reexecution.
1927         if (!live_locals.at(i) && !local->is_top() && local != lhs && local!= rhs) {
1928           uint idx = jvms->locoff() + i;
1929 #ifdef ASSERT
1930           if (Verbose) {
1931             tty->print("[unstable_if] kill local#%d: ", idx);
1932             local->dump();
1933             tty->cr();
1934           }
1935 #endif
1936           igvn.replace_input_of(unc, idx, top());
1937           modified = true;
1938         }
1939       }
1940     }
1941 
1942     // keep the mondified trap for late query
1943     if (modified) {
1944       trap->set_modified();
1945     } else {
1946       _unstable_if_traps.delete_at(i);
1947     }
1948   }
1949   igvn.optimize();
1950 }
1951 
1952 // StringOpts and late inlining of string methods
1953 void Compile::inline_string_calls(bool parse_time) {
1954   {
1955     // remove useless nodes to make the usage analysis simpler
1956     ResourceMark rm;
1957     PhaseRemoveUseless pru(initial_gvn(), *igvn_worklist());
1958   }
1959 
1960   {
1961     ResourceMark rm;
1962     print_method(PHASE_BEFORE_STRINGOPTS, 3);
1963     PhaseStringOpts pso(initial_gvn());
1964     print_method(PHASE_AFTER_STRINGOPTS, 3);
1965   }
1966 
1967   // now inline anything that we skipped the first time around
1968   if (!parse_time) {
1969     _late_inlines_pos = _late_inlines.length();
1970   }
1971 
1972   while (_string_late_inlines.length() > 0) {
1973     CallGenerator* cg = _string_late_inlines.pop();
1974     cg->do_late_inline();
1975     if (failing())  return;
1976   }
1977   _string_late_inlines.trunc_to(0);
1978 }
1979 
1980 // Late inlining of boxing methods
1981 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
1982   if (_boxing_late_inlines.length() > 0) {
1983     assert(has_boxed_value(), "inconsistent");
1984 
1985     PhaseGVN* gvn = initial_gvn();
1986     set_inlining_incrementally(true);
1987 
1988     igvn_worklist()->ensure_empty(); // should be done with igvn
1989 
1990     _late_inlines_pos = _late_inlines.length();
1991 
1992     while (_boxing_late_inlines.length() > 0) {
1993       CallGenerator* cg = _boxing_late_inlines.pop();
1994       cg->do_late_inline();
1995       if (failing())  return;
1996     }
1997     _boxing_late_inlines.trunc_to(0);
1998 
1999     inline_incrementally_cleanup(igvn);
2000 
2001     set_inlining_incrementally(false);
2002   }
2003 }
2004 
2005 bool Compile::inline_incrementally_one() {
2006   assert(IncrementalInline, "incremental inlining should be on");
2007 
2008   TracePhase tp("incrementalInline_inline", &timers[_t_incrInline_inline]);
2009 
2010   set_inlining_progress(false);
2011   set_do_cleanup(false);
2012 
2013   for (int i = 0; i < _late_inlines.length(); i++) {
2014     _late_inlines_pos = i+1;
2015     CallGenerator* cg = _late_inlines.at(i);
2016     bool does_dispatch = cg->is_virtual_late_inline() || cg->is_mh_late_inline();
2017     if (inlining_incrementally() || does_dispatch) { // a call can be either inlined or strength-reduced to a direct call
2018       cg->do_late_inline();
2019       assert(_late_inlines.at(i) == cg, "no insertions before current position allowed");
2020       if (failing()) {
2021         return false;
2022       } else if (inlining_progress()) {
2023         _late_inlines_pos = i+1; // restore the position in case new elements were inserted
2024         print_method(PHASE_INCREMENTAL_INLINE_STEP, 3, cg->call_node());
2025         break; // process one call site at a time
2026       }
2027     } else {
2028       // Ignore late inline direct calls when inlining is not allowed.
2029       // They are left in the late inline list when node budget is exhausted until the list is fully drained.
2030     }
2031   }
2032   // Remove processed elements.
2033   _late_inlines.remove_till(_late_inlines_pos);
2034   _late_inlines_pos = 0;
2035 
2036   assert(inlining_progress() || _late_inlines.length() == 0, "no progress");
2037 
2038   bool needs_cleanup = do_cleanup() || over_inlining_cutoff();
2039 
2040   set_inlining_progress(false);
2041   set_do_cleanup(false);
2042 
2043   bool force_cleanup = directive()->IncrementalInlineForceCleanupOption;
2044   return (_late_inlines.length() > 0) && !needs_cleanup && !force_cleanup;
2045 }
2046 
2047 void Compile::inline_incrementally_cleanup(PhaseIterGVN& igvn) {
2048   {
2049     TracePhase tp("incrementalInline_pru", &timers[_t_incrInline_pru]);
2050     ResourceMark rm;
2051     PhaseRemoveUseless pru(initial_gvn(), *igvn_worklist());
2052   }
2053   {
2054     TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
2055     igvn.reset_from_gvn(initial_gvn());
2056     igvn.optimize();
2057   }
2058   print_method(PHASE_INCREMENTAL_INLINE_CLEANUP, 3);
2059 }
2060 
2061 // Perform incremental inlining until bound on number of live nodes is reached
2062 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
2063   TracePhase tp("incrementalInline", &timers[_t_incrInline]);
2064 
2065   set_inlining_incrementally(true);
2066   uint low_live_nodes = 0;
2067 
2068   while (_late_inlines.length() > 0) {
2069     if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2070       if (low_live_nodes < (uint)LiveNodeCountInliningCutoff * 8 / 10) {
2071         TracePhase tp("incrementalInline_ideal", &timers[_t_incrInline_ideal]);
2072         // PhaseIdealLoop is expensive so we only try it once we are
2073         // out of live nodes and we only try it again if the previous
2074         // helped got the number of nodes down significantly
2075         PhaseIdealLoop::optimize(igvn, LoopOptsNone);
2076         if (failing())  return;
2077         low_live_nodes = live_nodes();
2078         _major_progress = true;
2079       }
2080 
2081       if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2082         bool do_print_inlining = print_inlining() || print_intrinsics();
2083         if (do_print_inlining || log() != nullptr) {
2084           // Print inlining message for candidates that we couldn't inline for lack of space.
2085           for (int i = 0; i < _late_inlines.length(); i++) {
2086             CallGenerator* cg = _late_inlines.at(i);
2087             const char* msg = "live nodes > LiveNodeCountInliningCutoff";
2088             if (do_print_inlining) {
2089               cg->print_inlining_late(msg);
2090             }
2091             log_late_inline_failure(cg, msg);
2092           }
2093         }
2094         break; // finish
2095       }
2096     }
2097 
2098     igvn_worklist()->ensure_empty(); // should be done with igvn
2099 
2100     while (inline_incrementally_one()) {
2101       assert(!failing(), "inconsistent");
2102     }
2103     if (failing())  return;
2104 
2105     inline_incrementally_cleanup(igvn);
2106 
2107     print_method(PHASE_INCREMENTAL_INLINE_STEP, 3);
2108 
2109     if (failing())  return;
2110 
2111     if (_late_inlines.length() == 0) {
2112       break; // no more progress
2113     }
2114   }
2115 
2116   igvn_worklist()->ensure_empty(); // should be done with igvn
2117 
2118   if (_string_late_inlines.length() > 0) {
2119     assert(has_stringbuilder(), "inconsistent");
2120 
2121     inline_string_calls(false);
2122 
2123     if (failing())  return;
2124 
2125     inline_incrementally_cleanup(igvn);
2126   }
2127 
2128   set_inlining_incrementally(false);
2129 }
2130 
2131 void Compile::process_late_inline_calls_no_inline(PhaseIterGVN& igvn) {
2132   // "inlining_incrementally() == false" is used to signal that no inlining is allowed
2133   // (see LateInlineVirtualCallGenerator::do_late_inline_check() for details).
2134   // Tracking and verification of modified nodes is disabled by setting "_modified_nodes == nullptr"
2135   // as if "inlining_incrementally() == true" were set.
2136   assert(inlining_incrementally() == false, "not allowed");
2137   assert(_modified_nodes == nullptr, "not allowed");
2138   assert(_late_inlines.length() > 0, "sanity");
2139 
2140   while (_late_inlines.length() > 0) {
2141     igvn_worklist()->ensure_empty(); // should be done with igvn
2142 
2143     while (inline_incrementally_one()) {
2144       assert(!failing(), "inconsistent");
2145     }
2146     if (failing())  return;
2147 
2148     inline_incrementally_cleanup(igvn);
2149   }
2150 }
2151 
2152 bool Compile::optimize_loops(PhaseIterGVN& igvn, LoopOptsMode mode) {
2153   if (_loop_opts_cnt > 0) {
2154     while (major_progress() && (_loop_opts_cnt > 0)) {
2155       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2156       PhaseIdealLoop::optimize(igvn, mode);
2157       _loop_opts_cnt--;
2158       if (failing())  return false;
2159       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
2160     }
2161   }
2162   return true;
2163 }
2164 
2165 // Remove edges from "root" to each SafePoint at a backward branch.
2166 // They were inserted during parsing (see add_safepoint()) to make
2167 // infinite loops without calls or exceptions visible to root, i.e.,
2168 // useful.
2169 void Compile::remove_root_to_sfpts_edges(PhaseIterGVN& igvn) {
2170   Node *r = root();
2171   if (r != nullptr) {
2172     for (uint i = r->req(); i < r->len(); ++i) {
2173       Node *n = r->in(i);
2174       if (n != nullptr && n->is_SafePoint()) {
2175         r->rm_prec(i);
2176         if (n->outcnt() == 0) {
2177           igvn.remove_dead_node(n);
2178         }
2179         --i;
2180       }
2181     }
2182     // Parsing may have added top inputs to the root node (Path
2183     // leading to the Halt node proven dead). Make sure we get a
2184     // chance to clean them up.
2185     igvn._worklist.push(r);
2186     igvn.optimize();
2187   }
2188 }
2189 
2190 //------------------------------Optimize---------------------------------------
2191 // Given a graph, optimize it.
2192 void Compile::Optimize() {
2193   TracePhase tp("optimizer", &timers[_t_optimizer]);
2194 
2195 #ifndef PRODUCT
2196   if (env()->break_at_compile()) {
2197     BREAKPOINT;
2198   }
2199 
2200 #endif
2201 
2202   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
2203 #ifdef ASSERT
2204   bs->verify_gc_barriers(this, BarrierSetC2::BeforeOptimize);
2205 #endif
2206 
2207   ResourceMark rm;
2208 
2209   print_inlining_reinit();
2210 
2211   NOT_PRODUCT( verify_graph_edges(); )
2212 
2213   print_method(PHASE_AFTER_PARSING, 1);
2214 
2215  {
2216   // Iterative Global Value Numbering, including ideal transforms
2217   // Initialize IterGVN with types and values from parse-time GVN
2218   PhaseIterGVN igvn(initial_gvn());
2219 #ifdef ASSERT
2220   _modified_nodes = new (comp_arena()) Unique_Node_List(comp_arena());
2221 #endif
2222   {
2223     TracePhase tp("iterGVN", &timers[_t_iterGVN]);
2224     igvn.optimize();
2225   }
2226 
2227   if (failing())  return;
2228 
2229   print_method(PHASE_ITER_GVN1, 2);
2230 
2231   process_for_unstable_if_traps(igvn);
2232 
2233   inline_incrementally(igvn);
2234 
2235   print_method(PHASE_INCREMENTAL_INLINE, 2);
2236 
2237   if (failing())  return;
2238 
2239   if (eliminate_boxing()) {
2240     // Inline valueOf() methods now.
2241     inline_boxing_calls(igvn);
2242 
2243     if (AlwaysIncrementalInline) {
2244       inline_incrementally(igvn);
2245     }
2246 
2247     print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
2248 
2249     if (failing())  return;
2250   }
2251 
2252   // Remove the speculative part of types and clean up the graph from
2253   // the extra CastPP nodes whose only purpose is to carry them. Do
2254   // that early so that optimizations are not disrupted by the extra
2255   // CastPP nodes.
2256   remove_speculative_types(igvn);
2257 
2258   // No more new expensive nodes will be added to the list from here
2259   // so keep only the actual candidates for optimizations.
2260   cleanup_expensive_nodes(igvn);
2261 
2262   assert(EnableVectorSupport || !has_vbox_nodes(), "sanity");
2263   if (EnableVectorSupport && has_vbox_nodes()) {
2264     TracePhase tp("", &timers[_t_vector]);
2265     PhaseVector pv(igvn);
2266     pv.optimize_vector_boxes();
2267 
2268     print_method(PHASE_ITER_GVN_AFTER_VECTOR, 2);
2269   }
2270   assert(!has_vbox_nodes(), "sanity");
2271 
2272   if (!failing() && RenumberLiveNodes && live_nodes() + NodeLimitFudgeFactor < unique()) {
2273     Compile::TracePhase tp("", &timers[_t_renumberLive]);
2274     igvn_worklist()->ensure_empty(); // should be done with igvn
2275     {
2276       ResourceMark rm;
2277       PhaseRenumberLive prl(initial_gvn(), *igvn_worklist());
2278     }
2279     igvn.reset_from_gvn(initial_gvn());
2280     igvn.optimize();
2281   }
2282 
2283   // Now that all inlining is over and no PhaseRemoveUseless will run, cut edge from root to loop
2284   // safepoints
2285   remove_root_to_sfpts_edges(igvn);
2286 
2287   // Perform escape analysis
2288   if (do_escape_analysis() && ConnectionGraph::has_candidates(this)) {
2289     if (has_loops()) {
2290       // Cleanup graph (remove dead nodes).
2291       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2292       PhaseIdealLoop::optimize(igvn, LoopOptsMaxUnroll);
2293       if (major_progress()) print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
2294       if (failing())  return;
2295     }
2296     bool progress;
2297     do {
2298       ConnectionGraph::do_analysis(this, &igvn);
2299 
2300       if (failing())  return;
2301 
2302       int mcount = macro_count(); // Record number of allocations and locks before IGVN
2303 
2304       // Optimize out fields loads from scalar replaceable allocations.
2305       igvn.optimize();
2306       print_method(PHASE_ITER_GVN_AFTER_EA, 2);
2307 
2308       if (failing())  return;
2309 
2310       if (congraph() != nullptr && macro_count() > 0) {
2311         TracePhase tp("macroEliminate", &timers[_t_macroEliminate]);
2312         PhaseMacroExpand mexp(igvn);
2313         mexp.eliminate_macro_nodes();
2314         igvn.set_delay_transform(false);
2315 
2316         igvn.optimize();
2317         print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
2318 
2319         if (failing())  return;
2320       }
2321       progress = do_iterative_escape_analysis() &&
2322                  (macro_count() < mcount) &&
2323                  ConnectionGraph::has_candidates(this);
2324       // Try again if candidates exist and made progress
2325       // by removing some allocations and/or locks.
2326     } while (progress);
2327   }
2328 
2329   // Loop transforms on the ideal graph.  Range Check Elimination,
2330   // peeling, unrolling, etc.
2331 
2332   // Set loop opts counter
2333   if((_loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
2334     {
2335       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2336       PhaseIdealLoop::optimize(igvn, LoopOptsDefault);
2337       _loop_opts_cnt--;
2338       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
2339       if (failing())  return;
2340     }
2341     // Loop opts pass if partial peeling occurred in previous pass
2342     if(PartialPeelLoop && major_progress() && (_loop_opts_cnt > 0)) {
2343       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2344       PhaseIdealLoop::optimize(igvn, LoopOptsSkipSplitIf);
2345       _loop_opts_cnt--;
2346       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
2347       if (failing())  return;
2348     }
2349     // Loop opts pass for loop-unrolling before CCP
2350     if(major_progress() && (_loop_opts_cnt > 0)) {
2351       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2352       PhaseIdealLoop::optimize(igvn, LoopOptsSkipSplitIf);
2353       _loop_opts_cnt--;
2354       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
2355     }
2356     if (!failing()) {
2357       // Verify that last round of loop opts produced a valid graph
2358       PhaseIdealLoop::verify(igvn);
2359     }
2360   }
2361   if (failing())  return;
2362 
2363   // Conditional Constant Propagation;
2364   PhaseCCP ccp( &igvn );
2365   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
2366   {
2367     TracePhase tp("ccp", &timers[_t_ccp]);
2368     ccp.do_transform();
2369   }
2370   print_method(PHASE_CCP1, 2);
2371 
2372   assert( true, "Break here to ccp.dump_old2new_map()");
2373 
2374   // Iterative Global Value Numbering, including ideal transforms
2375   {
2376     TracePhase tp("iterGVN2", &timers[_t_iterGVN2]);
2377     igvn.reset_from_igvn(&ccp);
2378     igvn.optimize();
2379   }
2380   print_method(PHASE_ITER_GVN2, 2);
2381 
2382   if (failing())  return;
2383 
2384   // Loop transforms on the ideal graph.  Range Check Elimination,
2385   // peeling, unrolling, etc.
2386   if (!optimize_loops(igvn, LoopOptsDefault)) {
2387     return;
2388   }
2389 
2390   if (failing())  return;
2391 
2392   C->clear_major_progress(); // ensure that major progress is now clear
2393 
2394   process_for_post_loop_opts_igvn(igvn);
2395 
2396 #ifdef ASSERT
2397   bs->verify_gc_barriers(this, BarrierSetC2::BeforeMacroExpand);
2398 #endif
2399 
2400   {
2401     TracePhase tp("macroExpand", &timers[_t_macroExpand]);
2402     PhaseMacroExpand  mex(igvn);
2403     if (mex.expand_macro_nodes()) {
2404       assert(failing(), "must bail out w/ explicit message");
2405       return;
2406     }
2407     print_method(PHASE_MACRO_EXPANSION, 2);
2408   }
2409 
2410   {
2411     TracePhase tp("barrierExpand", &timers[_t_barrierExpand]);
2412     if (bs->expand_barriers(this, igvn)) {
2413       assert(failing(), "must bail out w/ explicit message");
2414       return;
2415     }
2416     print_method(PHASE_BARRIER_EXPANSION, 2);
2417   }
2418 
2419   if (C->max_vector_size() > 0) {
2420     C->optimize_logic_cones(igvn);
2421     igvn.optimize();
2422   }
2423 
2424   DEBUG_ONLY( _modified_nodes = nullptr; )
2425 
2426   assert(igvn._worklist.size() == 0, "not empty");
2427 
2428   assert(_late_inlines.length() == 0 || IncrementalInlineMH || IncrementalInlineVirtual, "not empty");
2429 
2430   if (_late_inlines.length() > 0) {
2431     // More opportunities to optimize virtual and MH calls.
2432     // Though it's maybe too late to perform inlining, strength-reducing them to direct calls is still an option.
2433     process_late_inline_calls_no_inline(igvn);
2434   }
2435  } // (End scope of igvn; run destructor if necessary for asserts.)
2436 
2437  check_no_dead_use();
2438 
2439  process_print_inlining();
2440 
2441  // We will never use the NodeHash table any more. Clear it so that final_graph_reshaping does not have
2442  // to remove hashes to unlock nodes for modifications.
2443  C->node_hash()->clear();
2444 
2445  // A method with only infinite loops has no edges entering loops from root
2446  {
2447    TracePhase tp("graphReshape", &timers[_t_graphReshaping]);
2448    if (final_graph_reshaping()) {
2449      assert(failing(), "must bail out w/ explicit message");
2450      return;
2451    }
2452  }
2453 
2454  print_method(PHASE_OPTIMIZE_FINISHED, 2);
2455  DEBUG_ONLY(set_phase_optimize_finished();)
2456 }
2457 
2458 #ifdef ASSERT
2459 void Compile::check_no_dead_use() const {
2460   ResourceMark rm;
2461   Unique_Node_List wq;
2462   wq.push(root());
2463   for (uint i = 0; i < wq.size(); ++i) {
2464     Node* n = wq.at(i);
2465     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
2466       Node* u = n->fast_out(j);
2467       if (u->outcnt() == 0 && !u->is_Con()) {
2468         u->dump();
2469         fatal("no reachable node should have no use");
2470       }
2471       wq.push(u);
2472     }
2473   }
2474 }
2475 #endif
2476 
2477 void Compile::inline_vector_reboxing_calls() {
2478   if (C->_vector_reboxing_late_inlines.length() > 0) {
2479     _late_inlines_pos = C->_late_inlines.length();
2480     while (_vector_reboxing_late_inlines.length() > 0) {
2481       CallGenerator* cg = _vector_reboxing_late_inlines.pop();
2482       cg->do_late_inline();
2483       if (failing())  return;
2484       print_method(PHASE_INLINE_VECTOR_REBOX, 3, cg->call_node());
2485     }
2486     _vector_reboxing_late_inlines.trunc_to(0);
2487   }
2488 }
2489 
2490 bool Compile::has_vbox_nodes() {
2491   if (C->_vector_reboxing_late_inlines.length() > 0) {
2492     return true;
2493   }
2494   for (int macro_idx = C->macro_count() - 1; macro_idx >= 0; macro_idx--) {
2495     Node * n = C->macro_node(macro_idx);
2496     assert(n->is_macro(), "only macro nodes expected here");
2497     if (n->Opcode() == Op_VectorUnbox || n->Opcode() == Op_VectorBox || n->Opcode() == Op_VectorBoxAllocate) {
2498       return true;
2499     }
2500   }
2501   return false;
2502 }
2503 
2504 //---------------------------- Bitwise operation packing optimization ---------------------------
2505 
2506 static bool is_vector_unary_bitwise_op(Node* n) {
2507   return n->Opcode() == Op_XorV &&
2508          VectorNode::is_vector_bitwise_not_pattern(n);
2509 }
2510 
2511 static bool is_vector_binary_bitwise_op(Node* n) {
2512   switch (n->Opcode()) {
2513     case Op_AndV:
2514     case Op_OrV:
2515       return true;
2516 
2517     case Op_XorV:
2518       return !is_vector_unary_bitwise_op(n);
2519 
2520     default:
2521       return false;
2522   }
2523 }
2524 
2525 static bool is_vector_ternary_bitwise_op(Node* n) {
2526   return n->Opcode() == Op_MacroLogicV;
2527 }
2528 
2529 static bool is_vector_bitwise_op(Node* n) {
2530   return is_vector_unary_bitwise_op(n)  ||
2531          is_vector_binary_bitwise_op(n) ||
2532          is_vector_ternary_bitwise_op(n);
2533 }
2534 
2535 static bool is_vector_bitwise_cone_root(Node* n) {
2536   if (n->bottom_type()->isa_vectmask() || !is_vector_bitwise_op(n)) {
2537     return false;
2538   }
2539   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2540     if (is_vector_bitwise_op(n->fast_out(i))) {
2541       return false;
2542     }
2543   }
2544   return true;
2545 }
2546 
2547 static uint collect_unique_inputs(Node* n, Unique_Node_List& inputs) {
2548   uint cnt = 0;
2549   if (is_vector_bitwise_op(n)) {
2550     uint inp_cnt = n->is_predicated_vector() ? n->req()-1 : n->req();
2551     if (VectorNode::is_vector_bitwise_not_pattern(n)) {
2552       for (uint i = 1; i < inp_cnt; i++) {
2553         Node* in = n->in(i);
2554         bool skip = VectorNode::is_all_ones_vector(in);
2555         if (!skip && !inputs.member(in)) {
2556           inputs.push(in);
2557           cnt++;
2558         }
2559       }
2560       assert(cnt <= 1, "not unary");
2561     } else {
2562       uint last_req = inp_cnt;
2563       if (is_vector_ternary_bitwise_op(n)) {
2564         last_req = inp_cnt - 1; // skip last input
2565       }
2566       for (uint i = 1; i < last_req; i++) {
2567         Node* def = n->in(i);
2568         if (!inputs.member(def)) {
2569           inputs.push(def);
2570           cnt++;
2571         }
2572       }
2573     }
2574   } else { // not a bitwise operations
2575     if (!inputs.member(n)) {
2576       inputs.push(n);
2577       cnt++;
2578     }
2579   }
2580   return cnt;
2581 }
2582 
2583 void Compile::collect_logic_cone_roots(Unique_Node_List& list) {
2584   Unique_Node_List useful_nodes;
2585   C->identify_useful_nodes(useful_nodes);
2586 
2587   for (uint i = 0; i < useful_nodes.size(); i++) {
2588     Node* n = useful_nodes.at(i);
2589     if (is_vector_bitwise_cone_root(n)) {
2590       list.push(n);
2591     }
2592   }
2593 }
2594 
2595 Node* Compile::xform_to_MacroLogicV(PhaseIterGVN& igvn,
2596                                     const TypeVect* vt,
2597                                     Unique_Node_List& partition,
2598                                     Unique_Node_List& inputs) {
2599   assert(partition.size() == 2 || partition.size() == 3, "not supported");
2600   assert(inputs.size()    == 2 || inputs.size()    == 3, "not supported");
2601   assert(Matcher::match_rule_supported_vector(Op_MacroLogicV, vt->length(), vt->element_basic_type()), "not supported");
2602 
2603   Node* in1 = inputs.at(0);
2604   Node* in2 = inputs.at(1);
2605   Node* in3 = (inputs.size() == 3 ? inputs.at(2) : in2);
2606 
2607   uint func = compute_truth_table(partition, inputs);
2608 
2609   Node* pn = partition.at(partition.size() - 1);
2610   Node* mask = pn->is_predicated_vector() ? pn->in(pn->req()-1) : nullptr;
2611   return igvn.transform(MacroLogicVNode::make(igvn, in1, in2, in3, mask, func, vt));
2612 }
2613 
2614 static uint extract_bit(uint func, uint pos) {
2615   return (func & (1 << pos)) >> pos;
2616 }
2617 
2618 //
2619 //  A macro logic node represents a truth table. It has 4 inputs,
2620 //  First three inputs corresponds to 3 columns of a truth table
2621 //  and fourth input captures the logic function.
2622 //
2623 //  eg.  fn = (in1 AND in2) OR in3;
2624 //
2625 //      MacroNode(in1,in2,in3,fn)
2626 //
2627 //  -----------------
2628 //  in1 in2 in3  fn
2629 //  -----------------
2630 //  0    0   0    0
2631 //  0    0   1    1
2632 //  0    1   0    0
2633 //  0    1   1    1
2634 //  1    0   0    0
2635 //  1    0   1    1
2636 //  1    1   0    1
2637 //  1    1   1    1
2638 //
2639 
2640 uint Compile::eval_macro_logic_op(uint func, uint in1 , uint in2, uint in3) {
2641   int res = 0;
2642   for (int i = 0; i < 8; i++) {
2643     int bit1 = extract_bit(in1, i);
2644     int bit2 = extract_bit(in2, i);
2645     int bit3 = extract_bit(in3, i);
2646 
2647     int func_bit_pos = (bit1 << 2 | bit2 << 1 | bit3);
2648     int func_bit = extract_bit(func, func_bit_pos);
2649 
2650     res |= func_bit << i;
2651   }
2652   return res;
2653 }
2654 
2655 static uint eval_operand(Node* n, ResourceHashtable<Node*,uint>& eval_map) {
2656   assert(n != nullptr, "");
2657   assert(eval_map.contains(n), "absent");
2658   return *(eval_map.get(n));
2659 }
2660 
2661 static void eval_operands(Node* n,
2662                           uint& func1, uint& func2, uint& func3,
2663                           ResourceHashtable<Node*,uint>& eval_map) {
2664   assert(is_vector_bitwise_op(n), "");
2665 
2666   if (is_vector_unary_bitwise_op(n)) {
2667     Node* opnd = n->in(1);
2668     if (VectorNode::is_vector_bitwise_not_pattern(n) && VectorNode::is_all_ones_vector(opnd)) {
2669       opnd = n->in(2);
2670     }
2671     func1 = eval_operand(opnd, eval_map);
2672   } else if (is_vector_binary_bitwise_op(n)) {
2673     func1 = eval_operand(n->in(1), eval_map);
2674     func2 = eval_operand(n->in(2), eval_map);
2675   } else {
2676     assert(is_vector_ternary_bitwise_op(n), "unknown operation");
2677     func1 = eval_operand(n->in(1), eval_map);
2678     func2 = eval_operand(n->in(2), eval_map);
2679     func3 = eval_operand(n->in(3), eval_map);
2680   }
2681 }
2682 
2683 uint Compile::compute_truth_table(Unique_Node_List& partition, Unique_Node_List& inputs) {
2684   assert(inputs.size() <= 3, "sanity");
2685   ResourceMark rm;
2686   uint res = 0;
2687   ResourceHashtable<Node*,uint> eval_map;
2688 
2689   // Populate precomputed functions for inputs.
2690   // Each input corresponds to one column of 3 input truth-table.
2691   uint input_funcs[] = { 0xAA,   // (_, _, c) -> c
2692                          0xCC,   // (_, b, _) -> b
2693                          0xF0 }; // (a, _, _) -> a
2694   for (uint i = 0; i < inputs.size(); i++) {
2695     eval_map.put(inputs.at(i), input_funcs[2-i]);
2696   }
2697 
2698   for (uint i = 0; i < partition.size(); i++) {
2699     Node* n = partition.at(i);
2700 
2701     uint func1 = 0, func2 = 0, func3 = 0;
2702     eval_operands(n, func1, func2, func3, eval_map);
2703 
2704     switch (n->Opcode()) {
2705       case Op_OrV:
2706         assert(func3 == 0, "not binary");
2707         res = func1 | func2;
2708         break;
2709       case Op_AndV:
2710         assert(func3 == 0, "not binary");
2711         res = func1 & func2;
2712         break;
2713       case Op_XorV:
2714         if (VectorNode::is_vector_bitwise_not_pattern(n)) {
2715           assert(func2 == 0 && func3 == 0, "not unary");
2716           res = (~func1) & 0xFF;
2717         } else {
2718           assert(func3 == 0, "not binary");
2719           res = func1 ^ func2;
2720         }
2721         break;
2722       case Op_MacroLogicV:
2723         // Ordering of inputs may change during evaluation of sub-tree
2724         // containing MacroLogic node as a child node, thus a re-evaluation
2725         // makes sure that function is evaluated in context of current
2726         // inputs.
2727         res = eval_macro_logic_op(n->in(4)->get_int(), func1, func2, func3);
2728         break;
2729 
2730       default: assert(false, "not supported: %s", n->Name());
2731     }
2732     assert(res <= 0xFF, "invalid");
2733     eval_map.put(n, res);
2734   }
2735   return res;
2736 }
2737 
2738 // Criteria under which nodes gets packed into a macro logic node:-
2739 //  1) Parent and both child nodes are all unmasked or masked with
2740 //     same predicates.
2741 //  2) Masked parent can be packed with left child if it is predicated
2742 //     and both have same predicates.
2743 //  3) Masked parent can be packed with right child if its un-predicated
2744 //     or has matching predication condition.
2745 //  4) An unmasked parent can be packed with an unmasked child.
2746 bool Compile::compute_logic_cone(Node* n, Unique_Node_List& partition, Unique_Node_List& inputs) {
2747   assert(partition.size() == 0, "not empty");
2748   assert(inputs.size() == 0, "not empty");
2749   if (is_vector_ternary_bitwise_op(n)) {
2750     return false;
2751   }
2752 
2753   bool is_unary_op = is_vector_unary_bitwise_op(n);
2754   if (is_unary_op) {
2755     assert(collect_unique_inputs(n, inputs) == 1, "not unary");
2756     return false; // too few inputs
2757   }
2758 
2759   bool pack_left_child = true;
2760   bool pack_right_child = true;
2761 
2762   bool left_child_LOP = is_vector_bitwise_op(n->in(1));
2763   bool right_child_LOP = is_vector_bitwise_op(n->in(2));
2764 
2765   int left_child_input_cnt = 0;
2766   int right_child_input_cnt = 0;
2767 
2768   bool parent_is_predicated = n->is_predicated_vector();
2769   bool left_child_predicated = n->in(1)->is_predicated_vector();
2770   bool right_child_predicated = n->in(2)->is_predicated_vector();
2771 
2772   Node* parent_pred = parent_is_predicated ? n->in(n->req()-1) : nullptr;
2773   Node* left_child_pred = left_child_predicated ? n->in(1)->in(n->in(1)->req()-1) : nullptr;
2774   Node* right_child_pred = right_child_predicated ? n->in(1)->in(n->in(1)->req()-1) : nullptr;
2775 
2776   do {
2777     if (pack_left_child && left_child_LOP &&
2778         ((!parent_is_predicated && !left_child_predicated) ||
2779         ((parent_is_predicated && left_child_predicated &&
2780           parent_pred == left_child_pred)))) {
2781        partition.push(n->in(1));
2782        left_child_input_cnt = collect_unique_inputs(n->in(1), inputs);
2783     } else {
2784        inputs.push(n->in(1));
2785        left_child_input_cnt = 1;
2786     }
2787 
2788     if (pack_right_child && right_child_LOP &&
2789         (!right_child_predicated ||
2790          (right_child_predicated && parent_is_predicated &&
2791           parent_pred == right_child_pred))) {
2792        partition.push(n->in(2));
2793        right_child_input_cnt = collect_unique_inputs(n->in(2), inputs);
2794     } else {
2795        inputs.push(n->in(2));
2796        right_child_input_cnt = 1;
2797     }
2798 
2799     if (inputs.size() > 3) {
2800       assert(partition.size() > 0, "");
2801       inputs.clear();
2802       partition.clear();
2803       if (left_child_input_cnt > right_child_input_cnt) {
2804         pack_left_child = false;
2805       } else {
2806         pack_right_child = false;
2807       }
2808     } else {
2809       break;
2810     }
2811   } while(true);
2812 
2813   if(partition.size()) {
2814     partition.push(n);
2815   }
2816 
2817   return (partition.size() == 2 || partition.size() == 3) &&
2818          (inputs.size()    == 2 || inputs.size()    == 3);
2819 }
2820 
2821 void Compile::process_logic_cone_root(PhaseIterGVN &igvn, Node *n, VectorSet &visited) {
2822   assert(is_vector_bitwise_op(n), "not a root");
2823 
2824   visited.set(n->_idx);
2825 
2826   // 1) Do a DFS walk over the logic cone.
2827   for (uint i = 1; i < n->req(); i++) {
2828     Node* in = n->in(i);
2829     if (!visited.test(in->_idx) && is_vector_bitwise_op(in)) {
2830       process_logic_cone_root(igvn, in, visited);
2831     }
2832   }
2833 
2834   // 2) Bottom up traversal: Merge node[s] with
2835   // the parent to form macro logic node.
2836   Unique_Node_List partition;
2837   Unique_Node_List inputs;
2838   if (compute_logic_cone(n, partition, inputs)) {
2839     const TypeVect* vt = n->bottom_type()->is_vect();
2840     Node* pn = partition.at(partition.size() - 1);
2841     Node* mask = pn->is_predicated_vector() ? pn->in(pn->req()-1) : nullptr;
2842     if (mask == nullptr ||
2843         Matcher::match_rule_supported_vector_masked(Op_MacroLogicV, vt->length(), vt->element_basic_type())) {
2844       Node* macro_logic = xform_to_MacroLogicV(igvn, vt, partition, inputs);
2845       VectorNode::trace_new_vector(macro_logic, "MacroLogic");
2846       igvn.replace_node(n, macro_logic);
2847     }
2848   }
2849 }
2850 
2851 void Compile::optimize_logic_cones(PhaseIterGVN &igvn) {
2852   ResourceMark rm;
2853   if (Matcher::match_rule_supported(Op_MacroLogicV)) {
2854     Unique_Node_List list;
2855     collect_logic_cone_roots(list);
2856 
2857     while (list.size() > 0) {
2858       Node* n = list.pop();
2859       const TypeVect* vt = n->bottom_type()->is_vect();
2860       bool supported = Matcher::match_rule_supported_vector(Op_MacroLogicV, vt->length(), vt->element_basic_type());
2861       if (supported) {
2862         VectorSet visited(comp_arena());
2863         process_logic_cone_root(igvn, n, visited);
2864       }
2865     }
2866   }
2867 }
2868 
2869 //------------------------------Code_Gen---------------------------------------
2870 // Given a graph, generate code for it
2871 void Compile::Code_Gen() {
2872   if (failing()) {
2873     return;
2874   }
2875 
2876   // Perform instruction selection.  You might think we could reclaim Matcher
2877   // memory PDQ, but actually the Matcher is used in generating spill code.
2878   // Internals of the Matcher (including some VectorSets) must remain live
2879   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
2880   // set a bit in reclaimed memory.
2881 
2882   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2883   // nodes.  Mapping is only valid at the root of each matched subtree.
2884   NOT_PRODUCT( verify_graph_edges(); )
2885 
2886   Matcher matcher;
2887   _matcher = &matcher;
2888   {
2889     TracePhase tp("matcher", &timers[_t_matcher]);
2890     matcher.match();
2891     if (failing()) {
2892       return;
2893     }
2894   }
2895   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2896   // nodes.  Mapping is only valid at the root of each matched subtree.
2897   NOT_PRODUCT( verify_graph_edges(); )
2898 
2899   // If you have too many nodes, or if matching has failed, bail out
2900   check_node_count(0, "out of nodes matching instructions");
2901   if (failing()) {
2902     return;
2903   }
2904 
2905   print_method(PHASE_MATCHING, 2);
2906 
2907   // Build a proper-looking CFG
2908   PhaseCFG cfg(node_arena(), root(), matcher);
2909   _cfg = &cfg;
2910   {
2911     TracePhase tp("scheduler", &timers[_t_scheduler]);
2912     bool success = cfg.do_global_code_motion();
2913     if (!success) {
2914       return;
2915     }
2916 
2917     print_method(PHASE_GLOBAL_CODE_MOTION, 2);
2918     NOT_PRODUCT( verify_graph_edges(); )
2919     cfg.verify();
2920   }
2921 
2922   PhaseChaitin regalloc(unique(), cfg, matcher, false);
2923   _regalloc = &regalloc;
2924   {
2925     TracePhase tp("regalloc", &timers[_t_registerAllocation]);
2926     // Perform register allocation.  After Chaitin, use-def chains are
2927     // no longer accurate (at spill code) and so must be ignored.
2928     // Node->LRG->reg mappings are still accurate.
2929     _regalloc->Register_Allocate();
2930 
2931     // Bail out if the allocator builds too many nodes
2932     if (failing()) {
2933       return;
2934     }
2935   }
2936 
2937   // Prior to register allocation we kept empty basic blocks in case the
2938   // the allocator needed a place to spill.  After register allocation we
2939   // are not adding any new instructions.  If any basic block is empty, we
2940   // can now safely remove it.
2941   {
2942     TracePhase tp("blockOrdering", &timers[_t_blockOrdering]);
2943     cfg.remove_empty_blocks();
2944     if (do_freq_based_layout()) {
2945       PhaseBlockLayout layout(cfg);
2946     } else {
2947       cfg.set_loop_alignment();
2948     }
2949     cfg.fixup_flow();
2950     cfg.remove_unreachable_blocks();
2951     cfg.verify_dominator_tree();
2952   }
2953 
2954   // Apply peephole optimizations
2955   if( OptoPeephole ) {
2956     TracePhase tp("peephole", &timers[_t_peephole]);
2957     PhasePeephole peep( _regalloc, cfg);
2958     peep.do_transform();
2959   }
2960 
2961   // Do late expand if CPU requires this.
2962   if (Matcher::require_postalloc_expand) {
2963     TracePhase tp("postalloc_expand", &timers[_t_postalloc_expand]);
2964     cfg.postalloc_expand(_regalloc);
2965   }
2966 
2967   // Convert Nodes to instruction bits in a buffer
2968   {
2969     TracePhase tp("output", &timers[_t_output]);
2970     PhaseOutput output;
2971     output.Output();
2972     if (failing())  return;
2973     output.install();
2974   }
2975 
2976   print_method(PHASE_FINAL_CODE, 1);
2977 
2978   // He's dead, Jim.
2979   _cfg     = (PhaseCFG*)((intptr_t)0xdeadbeef);
2980   _regalloc = (PhaseChaitin*)((intptr_t)0xdeadbeef);
2981 }
2982 
2983 //------------------------------Final_Reshape_Counts---------------------------
2984 // This class defines counters to help identify when a method
2985 // may/must be executed using hardware with only 24-bit precision.
2986 struct Final_Reshape_Counts : public StackObj {
2987   int  _call_count;             // count non-inlined 'common' calls
2988   int  _float_count;            // count float ops requiring 24-bit precision
2989   int  _double_count;           // count double ops requiring more precision
2990   int  _java_call_count;        // count non-inlined 'java' calls
2991   int  _inner_loop_count;       // count loops which need alignment
2992   VectorSet _visited;           // Visitation flags
2993   Node_List _tests;             // Set of IfNodes & PCTableNodes
2994 
2995   Final_Reshape_Counts() :
2996     _call_count(0), _float_count(0), _double_count(0),
2997     _java_call_count(0), _inner_loop_count(0) { }
2998 
2999   void inc_call_count  () { _call_count  ++; }
3000   void inc_float_count () { _float_count ++; }
3001   void inc_double_count() { _double_count++; }
3002   void inc_java_call_count() { _java_call_count++; }
3003   void inc_inner_loop_count() { _inner_loop_count++; }
3004 
3005   int  get_call_count  () const { return _call_count  ; }
3006   int  get_float_count () const { return _float_count ; }
3007   int  get_double_count() const { return _double_count; }
3008   int  get_java_call_count() const { return _java_call_count; }
3009   int  get_inner_loop_count() const { return _inner_loop_count; }
3010 };
3011 
3012 // Eliminate trivially redundant StoreCMs and accumulate their
3013 // precedence edges.
3014 void Compile::eliminate_redundant_card_marks(Node* n) {
3015   assert(n->Opcode() == Op_StoreCM, "expected StoreCM");
3016   if (n->in(MemNode::Address)->outcnt() > 1) {
3017     // There are multiple users of the same address so it might be
3018     // possible to eliminate some of the StoreCMs
3019     Node* mem = n->in(MemNode::Memory);
3020     Node* adr = n->in(MemNode::Address);
3021     Node* val = n->in(MemNode::ValueIn);
3022     Node* prev = n;
3023     bool done = false;
3024     // Walk the chain of StoreCMs eliminating ones that match.  As
3025     // long as it's a chain of single users then the optimization is
3026     // safe.  Eliminating partially redundant StoreCMs would require
3027     // cloning copies down the other paths.
3028     while (mem->Opcode() == Op_StoreCM && mem->outcnt() == 1 && !done) {
3029       if (adr == mem->in(MemNode::Address) &&
3030           val == mem->in(MemNode::ValueIn)) {
3031         // redundant StoreCM
3032         if (mem->req() > MemNode::OopStore) {
3033           // Hasn't been processed by this code yet.
3034           n->add_prec(mem->in(MemNode::OopStore));
3035         } else {
3036           // Already converted to precedence edge
3037           for (uint i = mem->req(); i < mem->len(); i++) {
3038             // Accumulate any precedence edges
3039             if (mem->in(i) != nullptr) {
3040               n->add_prec(mem->in(i));
3041             }
3042           }
3043           // Everything above this point has been processed.
3044           done = true;
3045         }
3046         // Eliminate the previous StoreCM
3047         prev->set_req(MemNode::Memory, mem->in(MemNode::Memory));
3048         assert(mem->outcnt() == 0, "should be dead");
3049         mem->disconnect_inputs(this);
3050       } else {
3051         prev = mem;
3052       }
3053       mem = prev->in(MemNode::Memory);
3054     }
3055   }
3056 }
3057 
3058 //------------------------------final_graph_reshaping_impl----------------------
3059 // Implement items 1-5 from final_graph_reshaping below.
3060 void Compile::final_graph_reshaping_impl(Node *n, Final_Reshape_Counts& frc, Unique_Node_List& dead_nodes) {
3061 
3062   if ( n->outcnt() == 0 ) return; // dead node
3063   uint nop = n->Opcode();
3064 
3065   // Check for 2-input instruction with "last use" on right input.
3066   // Swap to left input.  Implements item (2).
3067   if( n->req() == 3 &&          // two-input instruction
3068       n->in(1)->outcnt() > 1 && // left use is NOT a last use
3069       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
3070       n->in(2)->outcnt() == 1 &&// right use IS a last use
3071       !n->in(2)->is_Con() ) {   // right use is not a constant
3072     // Check for commutative opcode
3073     switch( nop ) {
3074     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
3075     case Op_MaxI:  case Op_MaxL:  case Op_MaxF:  case Op_MaxD:
3076     case Op_MinI:  case Op_MinL:  case Op_MinF:  case Op_MinD:
3077     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
3078     case Op_AndL:  case Op_XorL:  case Op_OrL:
3079     case Op_AndI:  case Op_XorI:  case Op_OrI: {
3080       // Move "last use" input to left by swapping inputs
3081       n->swap_edges(1, 2);
3082       break;
3083     }
3084     default:
3085       break;
3086     }
3087   }
3088 
3089 #ifdef ASSERT
3090   if( n->is_Mem() ) {
3091     int alias_idx = get_alias_index(n->as_Mem()->adr_type());
3092     assert( n->in(0) != nullptr || alias_idx != Compile::AliasIdxRaw ||
3093             // oop will be recorded in oop map if load crosses safepoint
3094             n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
3095                              LoadNode::is_immutable_value(n->in(MemNode::Address))),
3096             "raw memory operations should have control edge");
3097   }
3098   if (n->is_MemBar()) {
3099     MemBarNode* mb = n->as_MemBar();
3100     if (mb->trailing_store() || mb->trailing_load_store()) {
3101       assert(mb->leading_membar()->trailing_membar() == mb, "bad membar pair");
3102       Node* mem = BarrierSet::barrier_set()->barrier_set_c2()->step_over_gc_barrier(mb->in(MemBarNode::Precedent));
3103       assert((mb->trailing_store() && mem->is_Store() && mem->as_Store()->is_release()) ||
3104              (mb->trailing_load_store() && mem->is_LoadStore()), "missing mem op");
3105     } else if (mb->leading()) {
3106       assert(mb->trailing_membar()->leading_membar() == mb, "bad membar pair");
3107     }
3108   }
3109 #endif
3110   // Count FPU ops and common calls, implements item (3)
3111   bool gc_handled = BarrierSet::barrier_set()->barrier_set_c2()->final_graph_reshaping(this, n, nop, dead_nodes);
3112   if (!gc_handled) {
3113     final_graph_reshaping_main_switch(n, frc, nop, dead_nodes);
3114   }
3115 
3116   // Collect CFG split points
3117   if (n->is_MultiBranch() && !n->is_RangeCheck()) {
3118     frc._tests.push(n);
3119   }
3120 }
3121 
3122 void Compile::final_graph_reshaping_main_switch(Node* n, Final_Reshape_Counts& frc, uint nop, Unique_Node_List& dead_nodes) {
3123   switch( nop ) {
3124   // Count all float operations that may use FPU
3125   case Op_AddF:
3126   case Op_SubF:
3127   case Op_MulF:
3128   case Op_DivF:
3129   case Op_NegF:
3130   case Op_ModF:
3131   case Op_ConvI2F:
3132   case Op_ConF:
3133   case Op_CmpF:
3134   case Op_CmpF3:
3135   case Op_StoreF:
3136   case Op_LoadF:
3137   // case Op_ConvL2F: // longs are split into 32-bit halves
3138     frc.inc_float_count();
3139     break;
3140 
3141   case Op_ConvF2D:
3142   case Op_ConvD2F:
3143     frc.inc_float_count();
3144     frc.inc_double_count();
3145     break;
3146 
3147   // Count all double operations that may use FPU
3148   case Op_AddD:
3149   case Op_SubD:
3150   case Op_MulD:
3151   case Op_DivD:
3152   case Op_NegD:
3153   case Op_ModD:
3154   case Op_ConvI2D:
3155   case Op_ConvD2I:
3156   // case Op_ConvL2D: // handled by leaf call
3157   // case Op_ConvD2L: // handled by leaf call
3158   case Op_ConD:
3159   case Op_CmpD:
3160   case Op_CmpD3:
3161   case Op_StoreD:
3162   case Op_LoadD:
3163   case Op_LoadD_unaligned:
3164     frc.inc_double_count();
3165     break;
3166   case Op_Opaque1:              // Remove Opaque Nodes before matching
3167   case Op_Opaque3:
3168     n->subsume_by(n->in(1), this);
3169     break;
3170   case Op_CallStaticJava:
3171   case Op_CallJava:
3172   case Op_CallDynamicJava:
3173     frc.inc_java_call_count(); // Count java call site;
3174   case Op_CallRuntime:
3175   case Op_CallLeaf:
3176   case Op_CallLeafVector:
3177   case Op_CallLeafNoFP: {
3178     assert (n->is_Call(), "");
3179     CallNode *call = n->as_Call();
3180     // Count call sites where the FP mode bit would have to be flipped.
3181     // Do not count uncommon runtime calls:
3182     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
3183     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
3184     if (!call->is_CallStaticJava() || !call->as_CallStaticJava()->_name) {
3185       frc.inc_call_count();   // Count the call site
3186     } else {                  // See if uncommon argument is shared
3187       Node *n = call->in(TypeFunc::Parms);
3188       int nop = n->Opcode();
3189       // Clone shared simple arguments to uncommon calls, item (1).
3190       if (n->outcnt() > 1 &&
3191           !n->is_Proj() &&
3192           nop != Op_CreateEx &&
3193           nop != Op_CheckCastPP &&
3194           nop != Op_DecodeN &&
3195           nop != Op_DecodeNKlass &&
3196           !n->is_Mem() &&
3197           !n->is_Phi()) {
3198         Node *x = n->clone();
3199         call->set_req(TypeFunc::Parms, x);
3200       }
3201     }
3202     break;
3203   }
3204 
3205   case Op_StoreCM:
3206     {
3207       // Convert OopStore dependence into precedence edge
3208       Node* prec = n->in(MemNode::OopStore);
3209       n->del_req(MemNode::OopStore);
3210       n->add_prec(prec);
3211       eliminate_redundant_card_marks(n);
3212     }
3213 
3214     // fall through
3215 
3216   case Op_StoreB:
3217   case Op_StoreC:
3218   case Op_StoreI:
3219   case Op_StoreL:
3220   case Op_CompareAndSwapB:
3221   case Op_CompareAndSwapS:
3222   case Op_CompareAndSwapI:
3223   case Op_CompareAndSwapL:
3224   case Op_CompareAndSwapP:
3225   case Op_CompareAndSwapN:
3226   case Op_WeakCompareAndSwapB:
3227   case Op_WeakCompareAndSwapS:
3228   case Op_WeakCompareAndSwapI:
3229   case Op_WeakCompareAndSwapL:
3230   case Op_WeakCompareAndSwapP:
3231   case Op_WeakCompareAndSwapN:
3232   case Op_CompareAndExchangeB:
3233   case Op_CompareAndExchangeS:
3234   case Op_CompareAndExchangeI:
3235   case Op_CompareAndExchangeL:
3236   case Op_CompareAndExchangeP:
3237   case Op_CompareAndExchangeN:
3238   case Op_GetAndAddS:
3239   case Op_GetAndAddB:
3240   case Op_GetAndAddI:
3241   case Op_GetAndAddL:
3242   case Op_GetAndSetS:
3243   case Op_GetAndSetB:
3244   case Op_GetAndSetI:
3245   case Op_GetAndSetL:
3246   case Op_GetAndSetP:
3247   case Op_GetAndSetN:
3248   case Op_StoreP:
3249   case Op_StoreN:
3250   case Op_StoreNKlass:
3251   case Op_LoadB:
3252   case Op_LoadUB:
3253   case Op_LoadUS:
3254   case Op_LoadI:
3255   case Op_LoadKlass:
3256   case Op_LoadNKlass:
3257   case Op_LoadL:
3258   case Op_LoadL_unaligned:
3259   case Op_LoadP:
3260   case Op_LoadN:
3261   case Op_LoadRange:
3262   case Op_LoadS:
3263     break;
3264 
3265   case Op_AddP: {               // Assert sane base pointers
3266     Node *addp = n->in(AddPNode::Address);
3267     assert( !addp->is_AddP() ||
3268             addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
3269             addp->in(AddPNode::Base) == n->in(AddPNode::Base),
3270             "Base pointers must match (addp %u)", addp->_idx );
3271 #ifdef _LP64
3272     if ((UseCompressedOops || UseCompressedClassPointers) &&
3273         addp->Opcode() == Op_ConP &&
3274         addp == n->in(AddPNode::Base) &&
3275         n->in(AddPNode::Offset)->is_Con()) {
3276       // If the transformation of ConP to ConN+DecodeN is beneficial depends
3277       // on the platform and on the compressed oops mode.
3278       // Use addressing with narrow klass to load with offset on x86.
3279       // Some platforms can use the constant pool to load ConP.
3280       // Do this transformation here since IGVN will convert ConN back to ConP.
3281       const Type* t = addp->bottom_type();
3282       bool is_oop   = t->isa_oopptr() != nullptr;
3283       bool is_klass = t->isa_klassptr() != nullptr;
3284 
3285       if ((is_oop   && Matcher::const_oop_prefer_decode()  ) ||
3286           (is_klass && Matcher::const_klass_prefer_decode())) {
3287         Node* nn = nullptr;
3288 
3289         int op = is_oop ? Op_ConN : Op_ConNKlass;
3290 
3291         // Look for existing ConN node of the same exact type.
3292         Node* r  = root();
3293         uint cnt = r->outcnt();
3294         for (uint i = 0; i < cnt; i++) {
3295           Node* m = r->raw_out(i);
3296           if (m!= nullptr && m->Opcode() == op &&
3297               m->bottom_type()->make_ptr() == t) {
3298             nn = m;
3299             break;
3300           }
3301         }
3302         if (nn != nullptr) {
3303           // Decode a narrow oop to match address
3304           // [R12 + narrow_oop_reg<<3 + offset]
3305           if (is_oop) {
3306             nn = new DecodeNNode(nn, t);
3307           } else {
3308             nn = new DecodeNKlassNode(nn, t);
3309           }
3310           // Check for succeeding AddP which uses the same Base.
3311           // Otherwise we will run into the assertion above when visiting that guy.
3312           for (uint i = 0; i < n->outcnt(); ++i) {
3313             Node *out_i = n->raw_out(i);
3314             if (out_i && out_i->is_AddP() && out_i->in(AddPNode::Base) == addp) {
3315               out_i->set_req(AddPNode::Base, nn);
3316 #ifdef ASSERT
3317               for (uint j = 0; j < out_i->outcnt(); ++j) {
3318                 Node *out_j = out_i->raw_out(j);
3319                 assert(out_j == nullptr || !out_j->is_AddP() || out_j->in(AddPNode::Base) != addp,
3320                        "more than 2 AddP nodes in a chain (out_j %u)", out_j->_idx);
3321               }
3322 #endif
3323             }
3324           }
3325           n->set_req(AddPNode::Base, nn);
3326           n->set_req(AddPNode::Address, nn);
3327           if (addp->outcnt() == 0) {
3328             addp->disconnect_inputs(this);
3329           }
3330         }
3331       }
3332     }
3333 #endif
3334     break;
3335   }
3336 
3337   case Op_CastPP: {
3338     // Remove CastPP nodes to gain more freedom during scheduling but
3339     // keep the dependency they encode as control or precedence edges
3340     // (if control is set already) on memory operations. Some CastPP
3341     // nodes don't have a control (don't carry a dependency): skip
3342     // those.
3343     if (n->in(0) != nullptr) {
3344       ResourceMark rm;
3345       Unique_Node_List wq;
3346       wq.push(n);
3347       for (uint next = 0; next < wq.size(); ++next) {
3348         Node *m = wq.at(next);
3349         for (DUIterator_Fast imax, i = m->fast_outs(imax); i < imax; i++) {
3350           Node* use = m->fast_out(i);
3351           if (use->is_Mem() || use->is_EncodeNarrowPtr()) {
3352             use->ensure_control_or_add_prec(n->in(0));
3353           } else {
3354             switch(use->Opcode()) {
3355             case Op_AddP:
3356             case Op_DecodeN:
3357             case Op_DecodeNKlass:
3358             case Op_CheckCastPP:
3359             case Op_CastPP:
3360               wq.push(use);
3361               break;
3362             }
3363           }
3364         }
3365       }
3366     }
3367     const bool is_LP64 = LP64_ONLY(true) NOT_LP64(false);
3368     if (is_LP64 && n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
3369       Node* in1 = n->in(1);
3370       const Type* t = n->bottom_type();
3371       Node* new_in1 = in1->clone();
3372       new_in1->as_DecodeN()->set_type(t);
3373 
3374       if (!Matcher::narrow_oop_use_complex_address()) {
3375         //
3376         // x86, ARM and friends can handle 2 adds in addressing mode
3377         // and Matcher can fold a DecodeN node into address by using
3378         // a narrow oop directly and do implicit null check in address:
3379         //
3380         // [R12 + narrow_oop_reg<<3 + offset]
3381         // NullCheck narrow_oop_reg
3382         //
3383         // On other platforms (Sparc) we have to keep new DecodeN node and
3384         // use it to do implicit null check in address:
3385         //
3386         // decode_not_null narrow_oop_reg, base_reg
3387         // [base_reg + offset]
3388         // NullCheck base_reg
3389         //
3390         // Pin the new DecodeN node to non-null path on these platform (Sparc)
3391         // to keep the information to which null check the new DecodeN node
3392         // corresponds to use it as value in implicit_null_check().
3393         //
3394         new_in1->set_req(0, n->in(0));
3395       }
3396 
3397       n->subsume_by(new_in1, this);
3398       if (in1->outcnt() == 0) {
3399         in1->disconnect_inputs(this);
3400       }
3401     } else {
3402       n->subsume_by(n->in(1), this);
3403       if (n->outcnt() == 0) {
3404         n->disconnect_inputs(this);
3405       }
3406     }
3407     break;
3408   }
3409 #ifdef _LP64
3410   case Op_CmpP:
3411     // Do this transformation here to preserve CmpPNode::sub() and
3412     // other TypePtr related Ideal optimizations (for example, ptr nullness).
3413     if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
3414       Node* in1 = n->in(1);
3415       Node* in2 = n->in(2);
3416       if (!in1->is_DecodeNarrowPtr()) {
3417         in2 = in1;
3418         in1 = n->in(2);
3419       }
3420       assert(in1->is_DecodeNarrowPtr(), "sanity");
3421 
3422       Node* new_in2 = nullptr;
3423       if (in2->is_DecodeNarrowPtr()) {
3424         assert(in2->Opcode() == in1->Opcode(), "must be same node type");
3425         new_in2 = in2->in(1);
3426       } else if (in2->Opcode() == Op_ConP) {
3427         const Type* t = in2->bottom_type();
3428         if (t == TypePtr::NULL_PTR) {
3429           assert(in1->is_DecodeN(), "compare klass to null?");
3430           // Don't convert CmpP null check into CmpN if compressed
3431           // oops implicit null check is not generated.
3432           // This will allow to generate normal oop implicit null check.
3433           if (Matcher::gen_narrow_oop_implicit_null_checks())
3434             new_in2 = ConNode::make(TypeNarrowOop::NULL_PTR);
3435           //
3436           // This transformation together with CastPP transformation above
3437           // will generated code for implicit null checks for compressed oops.
3438           //
3439           // The original code after Optimize()
3440           //
3441           //    LoadN memory, narrow_oop_reg
3442           //    decode narrow_oop_reg, base_reg
3443           //    CmpP base_reg, nullptr
3444           //    CastPP base_reg // NotNull
3445           //    Load [base_reg + offset], val_reg
3446           //
3447           // after these transformations will be
3448           //
3449           //    LoadN memory, narrow_oop_reg
3450           //    CmpN narrow_oop_reg, nullptr
3451           //    decode_not_null narrow_oop_reg, base_reg
3452           //    Load [base_reg + offset], val_reg
3453           //
3454           // and the uncommon path (== nullptr) will use narrow_oop_reg directly
3455           // since narrow oops can be used in debug info now (see the code in
3456           // final_graph_reshaping_walk()).
3457           //
3458           // At the end the code will be matched to
3459           // on x86:
3460           //
3461           //    Load_narrow_oop memory, narrow_oop_reg
3462           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
3463           //    NullCheck narrow_oop_reg
3464           //
3465           // and on sparc:
3466           //
3467           //    Load_narrow_oop memory, narrow_oop_reg
3468           //    decode_not_null narrow_oop_reg, base_reg
3469           //    Load [base_reg + offset], val_reg
3470           //    NullCheck base_reg
3471           //
3472         } else if (t->isa_oopptr()) {
3473           new_in2 = ConNode::make(t->make_narrowoop());
3474         } else if (t->isa_klassptr()) {
3475           new_in2 = ConNode::make(t->make_narrowklass());
3476         }
3477       }
3478       if (new_in2 != nullptr) {
3479         Node* cmpN = new CmpNNode(in1->in(1), new_in2);
3480         n->subsume_by(cmpN, this);
3481         if (in1->outcnt() == 0) {
3482           in1->disconnect_inputs(this);
3483         }
3484         if (in2->outcnt() == 0) {
3485           in2->disconnect_inputs(this);
3486         }
3487       }
3488     }
3489     break;
3490 
3491   case Op_DecodeN:
3492   case Op_DecodeNKlass:
3493     assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
3494     // DecodeN could be pinned when it can't be fold into
3495     // an address expression, see the code for Op_CastPP above.
3496     assert(n->in(0) == nullptr || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
3497     break;
3498 
3499   case Op_EncodeP:
3500   case Op_EncodePKlass: {
3501     Node* in1 = n->in(1);
3502     if (in1->is_DecodeNarrowPtr()) {
3503       n->subsume_by(in1->in(1), this);
3504     } else if (in1->Opcode() == Op_ConP) {
3505       const Type* t = in1->bottom_type();
3506       if (t == TypePtr::NULL_PTR) {
3507         assert(t->isa_oopptr(), "null klass?");
3508         n->subsume_by(ConNode::make(TypeNarrowOop::NULL_PTR), this);
3509       } else if (t->isa_oopptr()) {
3510         n->subsume_by(ConNode::make(t->make_narrowoop()), this);
3511       } else if (t->isa_klassptr()) {
3512         n->subsume_by(ConNode::make(t->make_narrowklass()), this);
3513       }
3514     }
3515     if (in1->outcnt() == 0) {
3516       in1->disconnect_inputs(this);
3517     }
3518     break;
3519   }
3520 
3521   case Op_Proj: {
3522     if (OptimizeStringConcat || IncrementalInline) {
3523       ProjNode* proj = n->as_Proj();
3524       if (proj->_is_io_use) {
3525         assert(proj->_con == TypeFunc::I_O || proj->_con == TypeFunc::Memory, "");
3526         // Separate projections were used for the exception path which
3527         // are normally removed by a late inline.  If it wasn't inlined
3528         // then they will hang around and should just be replaced with
3529         // the original one. Merge them.
3530         Node* non_io_proj = proj->in(0)->as_Multi()->proj_out_or_null(proj->_con, false /*is_io_use*/);
3531         if (non_io_proj  != nullptr) {
3532           proj->subsume_by(non_io_proj , this);
3533         }
3534       }
3535     }
3536     break;
3537   }
3538 
3539   case Op_Phi:
3540     if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
3541       // The EncodeP optimization may create Phi with the same edges
3542       // for all paths. It is not handled well by Register Allocator.
3543       Node* unique_in = n->in(1);
3544       assert(unique_in != nullptr, "");
3545       uint cnt = n->req();
3546       for (uint i = 2; i < cnt; i++) {
3547         Node* m = n->in(i);
3548         assert(m != nullptr, "");
3549         if (unique_in != m)
3550           unique_in = nullptr;
3551       }
3552       if (unique_in != nullptr) {
3553         n->subsume_by(unique_in, this);
3554       }
3555     }
3556     break;
3557 
3558 #endif
3559 
3560 #ifdef ASSERT
3561   case Op_CastII:
3562     // Verify that all range check dependent CastII nodes were removed.
3563     if (n->isa_CastII()->has_range_check()) {
3564       n->dump(3);
3565       assert(false, "Range check dependent CastII node was not removed");
3566     }
3567     break;
3568 #endif
3569 
3570   case Op_ModI:
3571     if (UseDivMod) {
3572       // Check if a%b and a/b both exist
3573       Node* d = n->find_similar(Op_DivI);
3574       if (d) {
3575         // Replace them with a fused divmod if supported
3576         if (Matcher::has_match_rule(Op_DivModI)) {
3577           DivModINode* divmod = DivModINode::make(n);
3578           d->subsume_by(divmod->div_proj(), this);
3579           n->subsume_by(divmod->mod_proj(), this);
3580         } else {
3581           // replace a%b with a-((a/b)*b)
3582           Node* mult = new MulINode(d, d->in(2));
3583           Node* sub  = new SubINode(d->in(1), mult);
3584           n->subsume_by(sub, this);
3585         }
3586       }
3587     }
3588     break;
3589 
3590   case Op_ModL:
3591     if (UseDivMod) {
3592       // Check if a%b and a/b both exist
3593       Node* d = n->find_similar(Op_DivL);
3594       if (d) {
3595         // Replace them with a fused divmod if supported
3596         if (Matcher::has_match_rule(Op_DivModL)) {
3597           DivModLNode* divmod = DivModLNode::make(n);
3598           d->subsume_by(divmod->div_proj(), this);
3599           n->subsume_by(divmod->mod_proj(), this);
3600         } else {
3601           // replace a%b with a-((a/b)*b)
3602           Node* mult = new MulLNode(d, d->in(2));
3603           Node* sub  = new SubLNode(d->in(1), mult);
3604           n->subsume_by(sub, this);
3605         }
3606       }
3607     }
3608     break;
3609 
3610   case Op_UModI:
3611     if (UseDivMod) {
3612       // Check if a%b and a/b both exist
3613       Node* d = n->find_similar(Op_UDivI);
3614       if (d) {
3615         // Replace them with a fused unsigned divmod if supported
3616         if (Matcher::has_match_rule(Op_UDivModI)) {
3617           UDivModINode* divmod = UDivModINode::make(n);
3618           d->subsume_by(divmod->div_proj(), this);
3619           n->subsume_by(divmod->mod_proj(), this);
3620         } else {
3621           // replace a%b with a-((a/b)*b)
3622           Node* mult = new MulINode(d, d->in(2));
3623           Node* sub  = new SubINode(d->in(1), mult);
3624           n->subsume_by(sub, this);
3625         }
3626       }
3627     }
3628     break;
3629 
3630   case Op_UModL:
3631     if (UseDivMod) {
3632       // Check if a%b and a/b both exist
3633       Node* d = n->find_similar(Op_UDivL);
3634       if (d) {
3635         // Replace them with a fused unsigned divmod if supported
3636         if (Matcher::has_match_rule(Op_UDivModL)) {
3637           UDivModLNode* divmod = UDivModLNode::make(n);
3638           d->subsume_by(divmod->div_proj(), this);
3639           n->subsume_by(divmod->mod_proj(), this);
3640         } else {
3641           // replace a%b with a-((a/b)*b)
3642           Node* mult = new MulLNode(d, d->in(2));
3643           Node* sub  = new SubLNode(d->in(1), mult);
3644           n->subsume_by(sub, this);
3645         }
3646       }
3647     }
3648     break;
3649 
3650   case Op_LoadVector:
3651   case Op_StoreVector:
3652   case Op_LoadVectorGather:
3653   case Op_StoreVectorScatter:
3654   case Op_LoadVectorGatherMasked:
3655   case Op_StoreVectorScatterMasked:
3656   case Op_VectorCmpMasked:
3657   case Op_VectorMaskGen:
3658   case Op_LoadVectorMasked:
3659   case Op_StoreVectorMasked:
3660     break;
3661 
3662   case Op_AddReductionVI:
3663   case Op_AddReductionVL:
3664   case Op_AddReductionVF:
3665   case Op_AddReductionVD:
3666   case Op_MulReductionVI:
3667   case Op_MulReductionVL:
3668   case Op_MulReductionVF:
3669   case Op_MulReductionVD:
3670   case Op_MinReductionV:
3671   case Op_MaxReductionV:
3672   case Op_AndReductionV:
3673   case Op_OrReductionV:
3674   case Op_XorReductionV:
3675     break;
3676 
3677   case Op_PackB:
3678   case Op_PackS:
3679   case Op_PackI:
3680   case Op_PackF:
3681   case Op_PackL:
3682   case Op_PackD:
3683     if (n->req()-1 > 2) {
3684       // Replace many operand PackNodes with a binary tree for matching
3685       PackNode* p = (PackNode*) n;
3686       Node* btp = p->binary_tree_pack(1, n->req());
3687       n->subsume_by(btp, this);
3688     }
3689     break;
3690   case Op_Loop:
3691     assert(!n->as_Loop()->is_loop_nest_inner_loop() || _loop_opts_cnt == 0, "should have been turned into a counted loop");
3692   case Op_CountedLoop:
3693   case Op_LongCountedLoop:
3694   case Op_OuterStripMinedLoop:
3695     if (n->as_Loop()->is_inner_loop()) {
3696       frc.inc_inner_loop_count();
3697     }
3698     n->as_Loop()->verify_strip_mined(0);
3699     break;
3700   case Op_LShiftI:
3701   case Op_RShiftI:
3702   case Op_URShiftI:
3703   case Op_LShiftL:
3704   case Op_RShiftL:
3705   case Op_URShiftL:
3706     if (Matcher::need_masked_shift_count) {
3707       // The cpu's shift instructions don't restrict the count to the
3708       // lower 5/6 bits. We need to do the masking ourselves.
3709       Node* in2 = n->in(2);
3710       juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
3711       const TypeInt* t = in2->find_int_type();
3712       if (t != nullptr && t->is_con()) {
3713         juint shift = t->get_con();
3714         if (shift > mask) { // Unsigned cmp
3715           n->set_req(2, ConNode::make(TypeInt::make(shift & mask)));
3716         }
3717       } else {
3718         if (t == nullptr || t->_lo < 0 || t->_hi > (int)mask) {
3719           Node* shift = new AndINode(in2, ConNode::make(TypeInt::make(mask)));
3720           n->set_req(2, shift);
3721         }
3722       }
3723       if (in2->outcnt() == 0) { // Remove dead node
3724         in2->disconnect_inputs(this);
3725       }
3726     }
3727     break;
3728   case Op_MemBarStoreStore:
3729   case Op_MemBarRelease:
3730     // Break the link with AllocateNode: it is no longer useful and
3731     // confuses register allocation.
3732     if (n->req() > MemBarNode::Precedent) {
3733       n->set_req(MemBarNode::Precedent, top());
3734     }
3735     break;
3736   case Op_MemBarAcquire: {
3737     if (n->as_MemBar()->trailing_load() && n->req() > MemBarNode::Precedent) {
3738       // At parse time, the trailing MemBarAcquire for a volatile load
3739       // is created with an edge to the load. After optimizations,
3740       // that input may be a chain of Phis. If those phis have no
3741       // other use, then the MemBarAcquire keeps them alive and
3742       // register allocation can be confused.
3743       dead_nodes.push(n->in(MemBarNode::Precedent));
3744       n->set_req(MemBarNode::Precedent, top());
3745     }
3746     break;
3747   }
3748   case Op_Blackhole:
3749     break;
3750   case Op_RangeCheck: {
3751     RangeCheckNode* rc = n->as_RangeCheck();
3752     Node* iff = new IfNode(rc->in(0), rc->in(1), rc->_prob, rc->_fcnt);
3753     n->subsume_by(iff, this);
3754     frc._tests.push(iff);
3755     break;
3756   }
3757   case Op_ConvI2L: {
3758     if (!Matcher::convi2l_type_required) {
3759       // Code generation on some platforms doesn't need accurate
3760       // ConvI2L types. Widening the type can help remove redundant
3761       // address computations.
3762       n->as_Type()->set_type(TypeLong::INT);
3763       ResourceMark rm;
3764       Unique_Node_List wq;
3765       wq.push(n);
3766       for (uint next = 0; next < wq.size(); next++) {
3767         Node *m = wq.at(next);
3768 
3769         for(;;) {
3770           // Loop over all nodes with identical inputs edges as m
3771           Node* k = m->find_similar(m->Opcode());
3772           if (k == nullptr) {
3773             break;
3774           }
3775           // Push their uses so we get a chance to remove node made
3776           // redundant
3777           for (DUIterator_Fast imax, i = k->fast_outs(imax); i < imax; i++) {
3778             Node* u = k->fast_out(i);
3779             if (u->Opcode() == Op_LShiftL ||
3780                 u->Opcode() == Op_AddL ||
3781                 u->Opcode() == Op_SubL ||
3782                 u->Opcode() == Op_AddP) {
3783               wq.push(u);
3784             }
3785           }
3786           // Replace all nodes with identical edges as m with m
3787           k->subsume_by(m, this);
3788         }
3789       }
3790     }
3791     break;
3792   }
3793   case Op_CmpUL: {
3794     if (!Matcher::has_match_rule(Op_CmpUL)) {
3795       // No support for unsigned long comparisons
3796       ConINode* sign_pos = new ConINode(TypeInt::make(BitsPerLong - 1));
3797       Node* sign_bit_mask = new RShiftLNode(n->in(1), sign_pos);
3798       Node* orl = new OrLNode(n->in(1), sign_bit_mask);
3799       ConLNode* remove_sign_mask = new ConLNode(TypeLong::make(max_jlong));
3800       Node* andl = new AndLNode(orl, remove_sign_mask);
3801       Node* cmp = new CmpLNode(andl, n->in(2));
3802       n->subsume_by(cmp, this);
3803     }
3804     break;
3805   }
3806   default:
3807     assert(!n->is_Call(), "");
3808     assert(!n->is_Mem(), "");
3809     assert(nop != Op_ProfileBoolean, "should be eliminated during IGVN");
3810     break;
3811   }
3812 }
3813 
3814 //------------------------------final_graph_reshaping_walk---------------------
3815 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
3816 // requires that the walk visits a node's inputs before visiting the node.
3817 void Compile::final_graph_reshaping_walk(Node_Stack& nstack, Node* root, Final_Reshape_Counts& frc, Unique_Node_List& dead_nodes) {
3818   Unique_Node_List sfpt;
3819 
3820   frc._visited.set(root->_idx); // first, mark node as visited
3821   uint cnt = root->req();
3822   Node *n = root;
3823   uint  i = 0;
3824   while (true) {
3825     if (i < cnt) {
3826       // Place all non-visited non-null inputs onto stack
3827       Node* m = n->in(i);
3828       ++i;
3829       if (m != nullptr && !frc._visited.test_set(m->_idx)) {
3830         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != nullptr) {
3831           // compute worst case interpreter size in case of a deoptimization
3832           update_interpreter_frame_size(m->as_SafePoint()->jvms()->interpreter_frame_size());
3833 
3834           sfpt.push(m);
3835         }
3836         cnt = m->req();
3837         nstack.push(n, i); // put on stack parent and next input's index
3838         n = m;
3839         i = 0;
3840       }
3841     } else {
3842       // Now do post-visit work
3843       final_graph_reshaping_impl(n, frc, dead_nodes);
3844       if (nstack.is_empty())
3845         break;             // finished
3846       n = nstack.node();   // Get node from stack
3847       cnt = n->req();
3848       i = nstack.index();
3849       nstack.pop();        // Shift to the next node on stack
3850     }
3851   }
3852 
3853   // Skip next transformation if compressed oops are not used.
3854   if ((UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks()) ||
3855       (!UseCompressedOops && !UseCompressedClassPointers))
3856     return;
3857 
3858   // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
3859   // It could be done for an uncommon traps or any safepoints/calls
3860   // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
3861   while (sfpt.size() > 0) {
3862     n = sfpt.pop();
3863     JVMState *jvms = n->as_SafePoint()->jvms();
3864     assert(jvms != nullptr, "sanity");
3865     int start = jvms->debug_start();
3866     int end   = n->req();
3867     bool is_uncommon = (n->is_CallStaticJava() &&
3868                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
3869     for (int j = start; j < end; j++) {
3870       Node* in = n->in(j);
3871       if (in->is_DecodeNarrowPtr()) {
3872         bool safe_to_skip = true;
3873         if (!is_uncommon ) {
3874           // Is it safe to skip?
3875           for (uint i = 0; i < in->outcnt(); i++) {
3876             Node* u = in->raw_out(i);
3877             if (!u->is_SafePoint() ||
3878                 (u->is_Call() && u->as_Call()->has_non_debug_use(n))) {
3879               safe_to_skip = false;
3880             }
3881           }
3882         }
3883         if (safe_to_skip) {
3884           n->set_req(j, in->in(1));
3885         }
3886         if (in->outcnt() == 0) {
3887           in->disconnect_inputs(this);
3888         }
3889       }
3890     }
3891   }
3892 }
3893 
3894 //------------------------------final_graph_reshaping--------------------------
3895 // Final Graph Reshaping.
3896 //
3897 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
3898 //     and not commoned up and forced early.  Must come after regular
3899 //     optimizations to avoid GVN undoing the cloning.  Clone constant
3900 //     inputs to Loop Phis; these will be split by the allocator anyways.
3901 //     Remove Opaque nodes.
3902 // (2) Move last-uses by commutative operations to the left input to encourage
3903 //     Intel update-in-place two-address operations and better register usage
3904 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
3905 //     calls canonicalizing them back.
3906 // (3) Count the number of double-precision FP ops, single-precision FP ops
3907 //     and call sites.  On Intel, we can get correct rounding either by
3908 //     forcing singles to memory (requires extra stores and loads after each
3909 //     FP bytecode) or we can set a rounding mode bit (requires setting and
3910 //     clearing the mode bit around call sites).  The mode bit is only used
3911 //     if the relative frequency of single FP ops to calls is low enough.
3912 //     This is a key transform for SPEC mpeg_audio.
3913 // (4) Detect infinite loops; blobs of code reachable from above but not
3914 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
3915 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
3916 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
3917 //     Detection is by looking for IfNodes where only 1 projection is
3918 //     reachable from below or CatchNodes missing some targets.
3919 // (5) Assert for insane oop offsets in debug mode.
3920 
3921 bool Compile::final_graph_reshaping() {
3922   // an infinite loop may have been eliminated by the optimizer,
3923   // in which case the graph will be empty.
3924   if (root()->req() == 1) {
3925     // Do not compile method that is only a trivial infinite loop,
3926     // since the content of the loop may have been eliminated.
3927     record_method_not_compilable("trivial infinite loop");
3928     return true;
3929   }
3930 
3931   // Expensive nodes have their control input set to prevent the GVN
3932   // from freely commoning them. There's no GVN beyond this point so
3933   // no need to keep the control input. We want the expensive nodes to
3934   // be freely moved to the least frequent code path by gcm.
3935   assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
3936   for (int i = 0; i < expensive_count(); i++) {
3937     _expensive_nodes.at(i)->set_req(0, nullptr);
3938   }
3939 
3940   Final_Reshape_Counts frc;
3941 
3942   // Visit everybody reachable!
3943   // Allocate stack of size C->live_nodes()/2 to avoid frequent realloc
3944   Node_Stack nstack(live_nodes() >> 1);
3945   Unique_Node_List dead_nodes;
3946   final_graph_reshaping_walk(nstack, root(), frc, dead_nodes);
3947 
3948   // Check for unreachable (from below) code (i.e., infinite loops).
3949   for( uint i = 0; i < frc._tests.size(); i++ ) {
3950     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
3951     // Get number of CFG targets.
3952     // Note that PCTables include exception targets after calls.
3953     uint required_outcnt = n->required_outcnt();
3954     if (n->outcnt() != required_outcnt) {
3955       // Check for a few special cases.  Rethrow Nodes never take the
3956       // 'fall-thru' path, so expected kids is 1 less.
3957       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
3958         if (n->in(0)->in(0)->is_Call()) {
3959           CallNode* call = n->in(0)->in(0)->as_Call();
3960           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
3961             required_outcnt--;      // Rethrow always has 1 less kid
3962           } else if (call->req() > TypeFunc::Parms &&
3963                      call->is_CallDynamicJava()) {
3964             // Check for null receiver. In such case, the optimizer has
3965             // detected that the virtual call will always result in a null
3966             // pointer exception. The fall-through projection of this CatchNode
3967             // will not be populated.
3968             Node* arg0 = call->in(TypeFunc::Parms);
3969             if (arg0->is_Type() &&
3970                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
3971               required_outcnt--;
3972             }
3973           } else if (call->entry_point() == OptoRuntime::new_array_Java() ||
3974                      call->entry_point() == OptoRuntime::new_array_nozero_Java()) {
3975             // Check for illegal array length. In such case, the optimizer has
3976             // detected that the allocation attempt will always result in an
3977             // exception. There is no fall-through projection of this CatchNode .
3978             assert(call->is_CallStaticJava(), "static call expected");
3979             assert(call->req() == call->jvms()->endoff() + 1, "missing extra input");
3980             uint valid_length_test_input = call->req() - 1;
3981             Node* valid_length_test = call->in(valid_length_test_input);
3982             call->del_req(valid_length_test_input);
3983             if (valid_length_test->find_int_con(1) == 0) {
3984               required_outcnt--;
3985             }
3986             dead_nodes.push(valid_length_test);
3987             assert(n->outcnt() == required_outcnt, "malformed control flow");
3988             continue;
3989           }
3990         }
3991       }
3992 
3993       // Recheck with a better notion of 'required_outcnt'
3994       if (n->outcnt() != required_outcnt) {
3995         record_method_not_compilable("malformed control flow");
3996         return true;            // Not all targets reachable!
3997       }
3998     } else if (n->is_PCTable() && n->in(0) && n->in(0)->in(0) && n->in(0)->in(0)->is_Call()) {
3999       CallNode* call = n->in(0)->in(0)->as_Call();
4000       if (call->entry_point() == OptoRuntime::new_array_Java() ||
4001           call->entry_point() == OptoRuntime::new_array_nozero_Java()) {
4002         assert(call->is_CallStaticJava(), "static call expected");
4003         assert(call->req() == call->jvms()->endoff() + 1, "missing extra input");
4004         uint valid_length_test_input = call->req() - 1;
4005         dead_nodes.push(call->in(valid_length_test_input));
4006         call->del_req(valid_length_test_input); // valid length test useless now
4007       }
4008     }
4009     // Check that I actually visited all kids.  Unreached kids
4010     // must be infinite loops.
4011     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
4012       if (!frc._visited.test(n->fast_out(j)->_idx)) {
4013         record_method_not_compilable("infinite loop");
4014         return true;            // Found unvisited kid; must be unreach
4015       }
4016 
4017     // Here so verification code in final_graph_reshaping_walk()
4018     // always see an OuterStripMinedLoopEnd
4019     if (n->is_OuterStripMinedLoopEnd() || n->is_LongCountedLoopEnd()) {
4020       IfNode* init_iff = n->as_If();
4021       Node* iff = new IfNode(init_iff->in(0), init_iff->in(1), init_iff->_prob, init_iff->_fcnt);
4022       n->subsume_by(iff, this);
4023     }
4024   }
4025 
4026   while (dead_nodes.size() > 0) {
4027     Node* m = dead_nodes.pop();
4028     if (m->outcnt() == 0 && m != top()) {
4029       for (uint j = 0; j < m->req(); j++) {
4030         Node* in = m->in(j);
4031         if (in != nullptr) {
4032           dead_nodes.push(in);
4033         }
4034       }
4035       m->disconnect_inputs(this);
4036     }
4037   }
4038 
4039 #ifdef IA32
4040   // If original bytecodes contained a mixture of floats and doubles
4041   // check if the optimizer has made it homogeneous, item (3).
4042   if (UseSSE == 0 &&
4043       frc.get_float_count() > 32 &&
4044       frc.get_double_count() == 0 &&
4045       (10 * frc.get_call_count() < frc.get_float_count()) ) {
4046     set_24_bit_selection_and_mode(false, true);
4047   }
4048 #endif // IA32
4049 
4050   set_java_calls(frc.get_java_call_count());
4051   set_inner_loops(frc.get_inner_loop_count());
4052 
4053   // No infinite loops, no reason to bail out.
4054   return false;
4055 }
4056 
4057 //-----------------------------too_many_traps----------------------------------
4058 // Report if there are too many traps at the current method and bci.
4059 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
4060 bool Compile::too_many_traps(ciMethod* method,
4061                              int bci,
4062                              Deoptimization::DeoptReason reason) {
4063   ciMethodData* md = method->method_data();
4064   if (md->is_empty()) {
4065     // Assume the trap has not occurred, or that it occurred only
4066     // because of a transient condition during start-up in the interpreter.
4067     return false;
4068   }
4069   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : nullptr;
4070   if (md->has_trap_at(bci, m, reason) != 0) {
4071     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
4072     // Also, if there are multiple reasons, or if there is no per-BCI record,
4073     // assume the worst.
4074     if (log())
4075       log()->elem("observe trap='%s' count='%d'",
4076                   Deoptimization::trap_reason_name(reason),
4077                   md->trap_count(reason));
4078     return true;
4079   } else {
4080     // Ignore method/bci and see if there have been too many globally.
4081     return too_many_traps(reason, md);
4082   }
4083 }
4084 
4085 // Less-accurate variant which does not require a method and bci.
4086 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
4087                              ciMethodData* logmd) {
4088   if (trap_count(reason) >= Deoptimization::per_method_trap_limit(reason)) {
4089     // Too many traps globally.
4090     // Note that we use cumulative trap_count, not just md->trap_count.
4091     if (log()) {
4092       int mcount = (logmd == nullptr)? -1: (int)logmd->trap_count(reason);
4093       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
4094                   Deoptimization::trap_reason_name(reason),
4095                   mcount, trap_count(reason));
4096     }
4097     return true;
4098   } else {
4099     // The coast is clear.
4100     return false;
4101   }
4102 }
4103 
4104 //--------------------------too_many_recompiles--------------------------------
4105 // Report if there are too many recompiles at the current method and bci.
4106 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
4107 // Is not eager to return true, since this will cause the compiler to use
4108 // Action_none for a trap point, to avoid too many recompilations.
4109 bool Compile::too_many_recompiles(ciMethod* method,
4110                                   int bci,
4111                                   Deoptimization::DeoptReason reason) {
4112   ciMethodData* md = method->method_data();
4113   if (md->is_empty()) {
4114     // Assume the trap has not occurred, or that it occurred only
4115     // because of a transient condition during start-up in the interpreter.
4116     return false;
4117   }
4118   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
4119   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
4120   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
4121   Deoptimization::DeoptReason per_bc_reason
4122     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
4123   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : nullptr;
4124   if ((per_bc_reason == Deoptimization::Reason_none
4125        || md->has_trap_at(bci, m, reason) != 0)
4126       // The trap frequency measure we care about is the recompile count:
4127       && md->trap_recompiled_at(bci, m)
4128       && md->overflow_recompile_count() >= bc_cutoff) {
4129     // Do not emit a trap here if it has already caused recompilations.
4130     // Also, if there are multiple reasons, or if there is no per-BCI record,
4131     // assume the worst.
4132     if (log())
4133       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
4134                   Deoptimization::trap_reason_name(reason),
4135                   md->trap_count(reason),
4136                   md->overflow_recompile_count());
4137     return true;
4138   } else if (trap_count(reason) != 0
4139              && decompile_count() >= m_cutoff) {
4140     // Too many recompiles globally, and we have seen this sort of trap.
4141     // Use cumulative decompile_count, not just md->decompile_count.
4142     if (log())
4143       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
4144                   Deoptimization::trap_reason_name(reason),
4145                   md->trap_count(reason), trap_count(reason),
4146                   md->decompile_count(), decompile_count());
4147     return true;
4148   } else {
4149     // The coast is clear.
4150     return false;
4151   }
4152 }
4153 
4154 // Compute when not to trap. Used by matching trap based nodes and
4155 // NullCheck optimization.
4156 void Compile::set_allowed_deopt_reasons() {
4157   _allowed_reasons = 0;
4158   if (is_method_compilation()) {
4159     for (int rs = (int)Deoptimization::Reason_none+1; rs < Compile::trapHistLength; rs++) {
4160       assert(rs < BitsPerInt, "recode bit map");
4161       if (!too_many_traps((Deoptimization::DeoptReason) rs)) {
4162         _allowed_reasons |= nth_bit(rs);
4163       }
4164     }
4165   }
4166 }
4167 
4168 bool Compile::needs_clinit_barrier(ciMethod* method, ciMethod* accessing_method) {
4169   return method->is_static() && needs_clinit_barrier(method->holder(), accessing_method);
4170 }
4171 
4172 bool Compile::needs_clinit_barrier(ciField* field, ciMethod* accessing_method) {
4173   return field->is_static() && needs_clinit_barrier(field->holder(), accessing_method);
4174 }
4175 
4176 bool Compile::needs_clinit_barrier(ciInstanceKlass* holder, ciMethod* accessing_method) {
4177   if (holder->is_initialized()) {
4178     return false;
4179   }
4180   if (holder->is_being_initialized()) {
4181     if (accessing_method->holder() == holder) {
4182       // Access inside a class. The barrier can be elided when access happens in <clinit>,
4183       // <init>, or a static method. In all those cases, there was an initialization
4184       // barrier on the holder klass passed.
4185       if (accessing_method->is_static_initializer() ||
4186           accessing_method->is_object_initializer() ||
4187           accessing_method->is_static()) {
4188         return false;
4189       }
4190     } else if (accessing_method->holder()->is_subclass_of(holder)) {
4191       // Access from a subclass. The barrier can be elided only when access happens in <clinit>.
4192       // In case of <init> or a static method, the barrier is on the subclass is not enough:
4193       // child class can become fully initialized while its parent class is still being initialized.
4194       if (accessing_method->is_static_initializer()) {
4195         return false;
4196       }
4197     }
4198     ciMethod* root = method(); // the root method of compilation
4199     if (root != accessing_method) {
4200       return needs_clinit_barrier(holder, root); // check access in the context of compilation root
4201     }
4202   }
4203   return true;
4204 }
4205 
4206 #ifndef PRODUCT
4207 //------------------------------verify_bidirectional_edges---------------------
4208 // For each input edge to a node (ie - for each Use-Def edge), verify that
4209 // there is a corresponding Def-Use edge.
4210 void Compile::verify_bidirectional_edges(Unique_Node_List &visited) {
4211   // Allocate stack of size C->live_nodes()/16 to avoid frequent realloc
4212   uint stack_size = live_nodes() >> 4;
4213   Node_List nstack(MAX2(stack_size, (uint)OptoNodeListSize));
4214   nstack.push(_root);
4215 
4216   while (nstack.size() > 0) {
4217     Node* n = nstack.pop();
4218     if (visited.member(n)) {
4219       continue;
4220     }
4221     visited.push(n);
4222 
4223     // Walk over all input edges, checking for correspondence
4224     uint length = n->len();
4225     for (uint i = 0; i < length; i++) {
4226       Node* in = n->in(i);
4227       if (in != nullptr && !visited.member(in)) {
4228         nstack.push(in); // Put it on stack
4229       }
4230       if (in != nullptr && !in->is_top()) {
4231         // Count instances of `next`
4232         int cnt = 0;
4233         for (uint idx = 0; idx < in->_outcnt; idx++) {
4234           if (in->_out[idx] == n) {
4235             cnt++;
4236           }
4237         }
4238         assert(cnt > 0, "Failed to find Def-Use edge.");
4239         // Check for duplicate edges
4240         // walk the input array downcounting the input edges to n
4241         for (uint j = 0; j < length; j++) {
4242           if (n->in(j) == in) {
4243             cnt--;
4244           }
4245         }
4246         assert(cnt == 0, "Mismatched edge count.");
4247       } else if (in == nullptr) {
4248         assert(i == 0 || i >= n->req() ||
4249                n->is_Region() || n->is_Phi() || n->is_ArrayCopy() ||
4250                (n->is_Unlock() && i == (n->req() - 1)) ||
4251                (n->is_MemBar() && i == 5), // the precedence edge to a membar can be removed during macro node expansion
4252               "only region, phi, arraycopy, unlock or membar nodes have null data edges");
4253       } else {
4254         assert(in->is_top(), "sanity");
4255         // Nothing to check.
4256       }
4257     }
4258   }
4259 }
4260 
4261 //------------------------------verify_graph_edges---------------------------
4262 // Walk the Graph and verify that there is a one-to-one correspondence
4263 // between Use-Def edges and Def-Use edges in the graph.
4264 void Compile::verify_graph_edges(bool no_dead_code) {
4265   if (VerifyGraphEdges) {
4266     Unique_Node_List visited;
4267 
4268     // Call graph walk to check edges
4269     verify_bidirectional_edges(visited);
4270     if (no_dead_code) {
4271       // Now make sure that no visited node is used by an unvisited node.
4272       bool dead_nodes = false;
4273       Unique_Node_List checked;
4274       while (visited.size() > 0) {
4275         Node* n = visited.pop();
4276         checked.push(n);
4277         for (uint i = 0; i < n->outcnt(); i++) {
4278           Node* use = n->raw_out(i);
4279           if (checked.member(use))  continue;  // already checked
4280           if (visited.member(use))  continue;  // already in the graph
4281           if (use->is_Con())        continue;  // a dead ConNode is OK
4282           // At this point, we have found a dead node which is DU-reachable.
4283           if (!dead_nodes) {
4284             tty->print_cr("*** Dead nodes reachable via DU edges:");
4285             dead_nodes = true;
4286           }
4287           use->dump(2);
4288           tty->print_cr("---");
4289           checked.push(use);  // No repeats; pretend it is now checked.
4290         }
4291       }
4292       assert(!dead_nodes, "using nodes must be reachable from root");
4293     }
4294   }
4295 }
4296 #endif
4297 
4298 // The Compile object keeps track of failure reasons separately from the ciEnv.
4299 // This is required because there is not quite a 1-1 relation between the
4300 // ciEnv and its compilation task and the Compile object.  Note that one
4301 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
4302 // to backtrack and retry without subsuming loads.  Other than this backtracking
4303 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
4304 // by the logic in C2Compiler.
4305 void Compile::record_failure(const char* reason) {
4306   if (log() != nullptr) {
4307     log()->elem("failure reason='%s' phase='compile'", reason);
4308   }
4309   if (_failure_reason == nullptr) {
4310     // Record the first failure reason.
4311     _failure_reason = reason;
4312   }
4313 
4314   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
4315     C->print_method(PHASE_FAILURE, 1);
4316   }
4317   _root = nullptr;  // flush the graph, too
4318 }
4319 
4320 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator)
4321   : TraceTime(name, accumulator, CITime, CITimeVerbose),
4322     _phase_name(name), _dolog(CITimeVerbose)
4323 {
4324   if (_dolog) {
4325     C = Compile::current();
4326     _log = C->log();
4327   } else {
4328     C = nullptr;
4329     _log = nullptr;
4330   }
4331   if (_log != nullptr) {
4332     _log->begin_head("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
4333     _log->stamp();
4334     _log->end_head();
4335   }
4336 }
4337 
4338 Compile::TracePhase::~TracePhase() {
4339 
4340   C = Compile::current();
4341   if (_dolog) {
4342     _log = C->log();
4343   } else {
4344     _log = nullptr;
4345   }
4346 
4347 #ifdef ASSERT
4348   if (PrintIdealNodeCount) {
4349     tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
4350                   _phase_name, C->unique(), C->live_nodes(), C->count_live_nodes_by_graph_walk());
4351   }
4352 
4353   if (VerifyIdealNodeCount) {
4354     Compile::current()->print_missing_nodes();
4355   }
4356 #endif
4357 
4358   if (_log != nullptr) {
4359     _log->done("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
4360   }
4361 }
4362 
4363 //----------------------------static_subtype_check-----------------------------
4364 // Shortcut important common cases when superklass is exact:
4365 // (0) superklass is java.lang.Object (can occur in reflective code)
4366 // (1) subklass is already limited to a subtype of superklass => always ok
4367 // (2) subklass does not overlap with superklass => always fail
4368 // (3) superklass has NO subtypes and we can check with a simple compare.
4369 Compile::SubTypeCheckResult Compile::static_subtype_check(const TypeKlassPtr* superk, const TypeKlassPtr* subk, bool skip) {
4370   if (skip) {
4371     return SSC_full_test;       // Let caller generate the general case.
4372   }
4373 
4374   if (subk->is_java_subtype_of(superk)) {
4375     return SSC_always_true; // (0) and (1)  this test cannot fail
4376   }
4377 
4378   if (!subk->maybe_java_subtype_of(superk)) {
4379     return SSC_always_false; // (2) true path dead; no dynamic test needed
4380   }
4381 
4382   const Type* superelem = superk;
4383   if (superk->isa_aryklassptr()) {
4384     int ignored;
4385     superelem = superk->is_aryklassptr()->base_element_type(ignored);
4386   }
4387 
4388   if (superelem->isa_instklassptr()) {
4389     ciInstanceKlass* ik = superelem->is_instklassptr()->instance_klass();
4390     if (!ik->has_subklass()) {
4391       if (!ik->is_final()) {
4392         // Add a dependency if there is a chance of a later subclass.
4393         dependencies()->assert_leaf_type(ik);
4394       }
4395       if (!superk->maybe_java_subtype_of(subk)) {
4396         return SSC_always_false;
4397       }
4398       return SSC_easy_test;     // (3) caller can do a simple ptr comparison
4399     }
4400   } else {
4401     // A primitive array type has no subtypes.
4402     return SSC_easy_test;       // (3) caller can do a simple ptr comparison
4403   }
4404 
4405   return SSC_full_test;
4406 }
4407 
4408 Node* Compile::conv_I2X_index(PhaseGVN* phase, Node* idx, const TypeInt* sizetype, Node* ctrl) {
4409 #ifdef _LP64
4410   // The scaled index operand to AddP must be a clean 64-bit value.
4411   // Java allows a 32-bit int to be incremented to a negative
4412   // value, which appears in a 64-bit register as a large
4413   // positive number.  Using that large positive number as an
4414   // operand in pointer arithmetic has bad consequences.
4415   // On the other hand, 32-bit overflow is rare, and the possibility
4416   // can often be excluded, if we annotate the ConvI2L node with
4417   // a type assertion that its value is known to be a small positive
4418   // number.  (The prior range check has ensured this.)
4419   // This assertion is used by ConvI2LNode::Ideal.
4420   int index_max = max_jint - 1;  // array size is max_jint, index is one less
4421   if (sizetype != nullptr) index_max = sizetype->_hi - 1;
4422   const TypeInt* iidxtype = TypeInt::make(0, index_max, Type::WidenMax);
4423   idx = constrained_convI2L(phase, idx, iidxtype, ctrl);
4424 #endif
4425   return idx;
4426 }
4427 
4428 // Convert integer value to a narrowed long type dependent on ctrl (for example, a range check)
4429 Node* Compile::constrained_convI2L(PhaseGVN* phase, Node* value, const TypeInt* itype, Node* ctrl, bool carry_dependency) {
4430   if (ctrl != nullptr) {
4431     // Express control dependency by a CastII node with a narrow type.
4432     value = new CastIINode(value, itype, carry_dependency ? ConstraintCastNode::StrongDependency : ConstraintCastNode::RegularDependency, true /* range check dependency */);
4433     // Make the CastII node dependent on the control input to prevent the narrowed ConvI2L
4434     // node from floating above the range check during loop optimizations. Otherwise, the
4435     // ConvI2L node may be eliminated independently of the range check, causing the data path
4436     // to become TOP while the control path is still there (although it's unreachable).
4437     value->set_req(0, ctrl);
4438     value = phase->transform(value);
4439   }
4440   const TypeLong* ltype = TypeLong::make(itype->_lo, itype->_hi, itype->_widen);
4441   return phase->transform(new ConvI2LNode(value, ltype));
4442 }
4443 
4444 // The message about the current inlining is accumulated in
4445 // _print_inlining_stream and transferred into the _print_inlining_list
4446 // once we know whether inlining succeeds or not. For regular
4447 // inlining, messages are appended to the buffer pointed by
4448 // _print_inlining_idx in the _print_inlining_list. For late inlining,
4449 // a new buffer is added after _print_inlining_idx in the list. This
4450 // way we can update the inlining message for late inlining call site
4451 // when the inlining is attempted again.
4452 void Compile::print_inlining_init() {
4453   if (print_inlining() || print_intrinsics()) {
4454     // print_inlining_init is actually called several times.
4455     print_inlining_reset();
4456     _print_inlining_list = new (comp_arena())GrowableArray<PrintInliningBuffer*>(comp_arena(), 1, 1, new PrintInliningBuffer());
4457   }
4458 }
4459 
4460 void Compile::print_inlining_reinit() {
4461   if (print_inlining() || print_intrinsics()) {
4462     print_inlining_reset();
4463   }
4464 }
4465 
4466 void Compile::print_inlining_reset() {
4467   _print_inlining_stream->reset();
4468 }
4469 
4470 void Compile::print_inlining_commit() {
4471   assert(print_inlining() || print_intrinsics(), "PrintInlining off?");
4472   // Transfer the message from _print_inlining_stream to the current
4473   // _print_inlining_list buffer and clear _print_inlining_stream.
4474   _print_inlining_list->at(_print_inlining_idx)->ss()->write(_print_inlining_stream->base(), _print_inlining_stream->size());
4475   print_inlining_reset();
4476 }
4477 
4478 void Compile::print_inlining_push() {
4479   // Add new buffer to the _print_inlining_list at current position
4480   _print_inlining_idx++;
4481   _print_inlining_list->insert_before(_print_inlining_idx, new PrintInliningBuffer());
4482 }
4483 
4484 Compile::PrintInliningBuffer* Compile::print_inlining_current() {
4485   return _print_inlining_list->at(_print_inlining_idx);
4486 }
4487 
4488 void Compile::print_inlining_update(CallGenerator* cg) {
4489   if (print_inlining() || print_intrinsics()) {
4490     if (cg->is_late_inline()) {
4491       if (print_inlining_current()->cg() != cg &&
4492           (print_inlining_current()->cg() != nullptr ||
4493            print_inlining_current()->ss()->size() != 0)) {
4494         print_inlining_push();
4495       }
4496       print_inlining_commit();
4497       print_inlining_current()->set_cg(cg);
4498     } else {
4499       if (print_inlining_current()->cg() != nullptr) {
4500         print_inlining_push();
4501       }
4502       print_inlining_commit();
4503     }
4504   }
4505 }
4506 
4507 void Compile::print_inlining_move_to(CallGenerator* cg) {
4508   // We resume inlining at a late inlining call site. Locate the
4509   // corresponding inlining buffer so that we can update it.
4510   if (print_inlining() || print_intrinsics()) {
4511     for (int i = 0; i < _print_inlining_list->length(); i++) {
4512       if (_print_inlining_list->at(i)->cg() == cg) {
4513         _print_inlining_idx = i;
4514         return;
4515       }
4516     }
4517     ShouldNotReachHere();
4518   }
4519 }
4520 
4521 void Compile::print_inlining_update_delayed(CallGenerator* cg) {
4522   if (print_inlining() || print_intrinsics()) {
4523     assert(_print_inlining_stream->size() > 0, "missing inlining msg");
4524     assert(print_inlining_current()->cg() == cg, "wrong entry");
4525     // replace message with new message
4526     _print_inlining_list->at_put(_print_inlining_idx, new PrintInliningBuffer());
4527     print_inlining_commit();
4528     print_inlining_current()->set_cg(cg);
4529   }
4530 }
4531 
4532 void Compile::print_inlining_assert_ready() {
4533   assert(!_print_inlining || _print_inlining_stream->size() == 0, "losing data");
4534 }
4535 
4536 void Compile::process_print_inlining() {
4537   assert(_late_inlines.length() == 0, "not drained yet");
4538   if (print_inlining() || print_intrinsics()) {
4539     ResourceMark rm;
4540     stringStream ss;
4541     assert(_print_inlining_list != nullptr, "process_print_inlining should be called only once.");
4542     for (int i = 0; i < _print_inlining_list->length(); i++) {
4543       PrintInliningBuffer* pib = _print_inlining_list->at(i);
4544       ss.print("%s", pib->ss()->freeze());
4545       delete pib;
4546       DEBUG_ONLY(_print_inlining_list->at_put(i, nullptr));
4547     }
4548     // Reset _print_inlining_list, it only contains destructed objects.
4549     // It is on the arena, so it will be freed when the arena is reset.
4550     _print_inlining_list = nullptr;
4551     // _print_inlining_stream won't be used anymore, either.
4552     print_inlining_reset();
4553     size_t end = ss.size();
4554     _print_inlining_output = NEW_ARENA_ARRAY(comp_arena(), char, end+1);
4555     strncpy(_print_inlining_output, ss.freeze(), end+1);
4556     _print_inlining_output[end] = 0;
4557   }
4558 }
4559 
4560 void Compile::dump_print_inlining() {
4561   if (_print_inlining_output != nullptr) {
4562     tty->print_raw(_print_inlining_output);
4563   }
4564 }
4565 
4566 void Compile::log_late_inline(CallGenerator* cg) {
4567   if (log() != nullptr) {
4568     log()->head("late_inline method='%d'  inline_id='" JLONG_FORMAT "'", log()->identify(cg->method()),
4569                 cg->unique_id());
4570     JVMState* p = cg->call_node()->jvms();
4571     while (p != nullptr) {
4572       log()->elem("jvms bci='%d' method='%d'", p->bci(), log()->identify(p->method()));
4573       p = p->caller();
4574     }
4575     log()->tail("late_inline");
4576   }
4577 }
4578 
4579 void Compile::log_late_inline_failure(CallGenerator* cg, const char* msg) {
4580   log_late_inline(cg);
4581   if (log() != nullptr) {
4582     log()->inline_fail(msg);
4583   }
4584 }
4585 
4586 void Compile::log_inline_id(CallGenerator* cg) {
4587   if (log() != nullptr) {
4588     // The LogCompilation tool needs a unique way to identify late
4589     // inline call sites. This id must be unique for this call site in
4590     // this compilation. Try to have it unique across compilations as
4591     // well because it can be convenient when grepping through the log
4592     // file.
4593     // Distinguish OSR compilations from others in case CICountOSR is
4594     // on.
4595     jlong id = ((jlong)unique()) + (((jlong)compile_id()) << 33) + (CICountOSR && is_osr_compilation() ? ((jlong)1) << 32 : 0);
4596     cg->set_unique_id(id);
4597     log()->elem("inline_id id='" JLONG_FORMAT "'", id);
4598   }
4599 }
4600 
4601 void Compile::log_inline_failure(const char* msg) {
4602   if (C->log() != nullptr) {
4603     C->log()->inline_fail(msg);
4604   }
4605 }
4606 
4607 
4608 // Dump inlining replay data to the stream.
4609 // Don't change thread state and acquire any locks.
4610 void Compile::dump_inline_data(outputStream* out) {
4611   InlineTree* inl_tree = ilt();
4612   if (inl_tree != nullptr) {
4613     out->print(" inline %d", inl_tree->count());
4614     inl_tree->dump_replay_data(out);
4615   }
4616 }
4617 
4618 void Compile::dump_inline_data_reduced(outputStream* out) {
4619   assert(ReplayReduce, "");
4620 
4621   InlineTree* inl_tree = ilt();
4622   if (inl_tree == nullptr) {
4623     return;
4624   }
4625   // Enable iterative replay file reduction
4626   // Output "compile" lines for depth 1 subtrees,
4627   // simulating that those trees were compiled
4628   // instead of inlined.
4629   for (int i = 0; i < inl_tree->subtrees().length(); ++i) {
4630     InlineTree* sub = inl_tree->subtrees().at(i);
4631     if (sub->inline_level() != 1) {
4632       continue;
4633     }
4634 
4635     ciMethod* method = sub->method();
4636     int entry_bci = -1;
4637     int comp_level = env()->task()->comp_level();
4638     out->print("compile ");
4639     method->dump_name_as_ascii(out);
4640     out->print(" %d %d", entry_bci, comp_level);
4641     out->print(" inline %d", sub->count());
4642     sub->dump_replay_data(out, -1);
4643     out->cr();
4644   }
4645 }
4646 
4647 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
4648   if (n1->Opcode() < n2->Opcode())      return -1;
4649   else if (n1->Opcode() > n2->Opcode()) return 1;
4650 
4651   assert(n1->req() == n2->req(), "can't compare %s nodes: n1->req() = %d, n2->req() = %d", NodeClassNames[n1->Opcode()], n1->req(), n2->req());
4652   for (uint i = 1; i < n1->req(); i++) {
4653     if (n1->in(i) < n2->in(i))      return -1;
4654     else if (n1->in(i) > n2->in(i)) return 1;
4655   }
4656 
4657   return 0;
4658 }
4659 
4660 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
4661   Node* n1 = *n1p;
4662   Node* n2 = *n2p;
4663 
4664   return cmp_expensive_nodes(n1, n2);
4665 }
4666 
4667 void Compile::sort_expensive_nodes() {
4668   if (!expensive_nodes_sorted()) {
4669     _expensive_nodes.sort(cmp_expensive_nodes);
4670   }
4671 }
4672 
4673 bool Compile::expensive_nodes_sorted() const {
4674   for (int i = 1; i < _expensive_nodes.length(); i++) {
4675     if (cmp_expensive_nodes(_expensive_nodes.adr_at(i), _expensive_nodes.adr_at(i-1)) < 0) {
4676       return false;
4677     }
4678   }
4679   return true;
4680 }
4681 
4682 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
4683   if (_expensive_nodes.length() == 0) {
4684     return false;
4685   }
4686 
4687   assert(OptimizeExpensiveOps, "optimization off?");
4688 
4689   // Take this opportunity to remove dead nodes from the list
4690   int j = 0;
4691   for (int i = 0; i < _expensive_nodes.length(); i++) {
4692     Node* n = _expensive_nodes.at(i);
4693     if (!n->is_unreachable(igvn)) {
4694       assert(n->is_expensive(), "should be expensive");
4695       _expensive_nodes.at_put(j, n);
4696       j++;
4697     }
4698   }
4699   _expensive_nodes.trunc_to(j);
4700 
4701   // Then sort the list so that similar nodes are next to each other
4702   // and check for at least two nodes of identical kind with same data
4703   // inputs.
4704   sort_expensive_nodes();
4705 
4706   for (int i = 0; i < _expensive_nodes.length()-1; i++) {
4707     if (cmp_expensive_nodes(_expensive_nodes.adr_at(i), _expensive_nodes.adr_at(i+1)) == 0) {
4708       return true;
4709     }
4710   }
4711 
4712   return false;
4713 }
4714 
4715 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
4716   if (_expensive_nodes.length() == 0) {
4717     return;
4718   }
4719 
4720   assert(OptimizeExpensiveOps, "optimization off?");
4721 
4722   // Sort to bring similar nodes next to each other and clear the
4723   // control input of nodes for which there's only a single copy.
4724   sort_expensive_nodes();
4725 
4726   int j = 0;
4727   int identical = 0;
4728   int i = 0;
4729   bool modified = false;
4730   for (; i < _expensive_nodes.length()-1; i++) {
4731     assert(j <= i, "can't write beyond current index");
4732     if (_expensive_nodes.at(i)->Opcode() == _expensive_nodes.at(i+1)->Opcode()) {
4733       identical++;
4734       _expensive_nodes.at_put(j++, _expensive_nodes.at(i));
4735       continue;
4736     }
4737     if (identical > 0) {
4738       _expensive_nodes.at_put(j++, _expensive_nodes.at(i));
4739       identical = 0;
4740     } else {
4741       Node* n = _expensive_nodes.at(i);
4742       igvn.replace_input_of(n, 0, nullptr);
4743       igvn.hash_insert(n);
4744       modified = true;
4745     }
4746   }
4747   if (identical > 0) {
4748     _expensive_nodes.at_put(j++, _expensive_nodes.at(i));
4749   } else if (_expensive_nodes.length() >= 1) {
4750     Node* n = _expensive_nodes.at(i);
4751     igvn.replace_input_of(n, 0, nullptr);
4752     igvn.hash_insert(n);
4753     modified = true;
4754   }
4755   _expensive_nodes.trunc_to(j);
4756   if (modified) {
4757     igvn.optimize();
4758   }
4759 }
4760 
4761 void Compile::add_expensive_node(Node * n) {
4762   assert(!_expensive_nodes.contains(n), "duplicate entry in expensive list");
4763   assert(n->is_expensive(), "expensive nodes with non-null control here only");
4764   assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
4765   if (OptimizeExpensiveOps) {
4766     _expensive_nodes.append(n);
4767   } else {
4768     // Clear control input and let IGVN optimize expensive nodes if
4769     // OptimizeExpensiveOps is off.
4770     n->set_req(0, nullptr);
4771   }
4772 }
4773 
4774 /**
4775  * Track coarsened Lock and Unlock nodes.
4776  */
4777 
4778 class Lock_List : public Node_List {
4779   uint _origin_cnt;
4780 public:
4781   Lock_List(Arena *a, uint cnt) : Node_List(a), _origin_cnt(cnt) {}
4782   uint origin_cnt() const { return _origin_cnt; }
4783 };
4784 
4785 void Compile::add_coarsened_locks(GrowableArray<AbstractLockNode*>& locks) {
4786   int length = locks.length();
4787   if (length > 0) {
4788     // Have to keep this list until locks elimination during Macro nodes elimination.
4789     Lock_List* locks_list = new (comp_arena()) Lock_List(comp_arena(), length);
4790     for (int i = 0; i < length; i++) {
4791       AbstractLockNode* lock = locks.at(i);
4792       assert(lock->is_coarsened(), "expecting only coarsened AbstractLock nodes, but got '%s'[%d] node", lock->Name(), lock->_idx);
4793       locks_list->push(lock);
4794     }
4795     _coarsened_locks.append(locks_list);
4796   }
4797 }
4798 
4799 void Compile::remove_useless_coarsened_locks(Unique_Node_List& useful) {
4800   int count = coarsened_count();
4801   for (int i = 0; i < count; i++) {
4802     Node_List* locks_list = _coarsened_locks.at(i);
4803     for (uint j = 0; j < locks_list->size(); j++) {
4804       Node* lock = locks_list->at(j);
4805       assert(lock->is_AbstractLock(), "sanity");
4806       if (!useful.member(lock)) {
4807         locks_list->yank(lock);
4808       }
4809     }
4810   }
4811 }
4812 
4813 void Compile::remove_coarsened_lock(Node* n) {
4814   if (n->is_AbstractLock()) {
4815     int count = coarsened_count();
4816     for (int i = 0; i < count; i++) {
4817       Node_List* locks_list = _coarsened_locks.at(i);
4818       locks_list->yank(n);
4819     }
4820   }
4821 }
4822 
4823 bool Compile::coarsened_locks_consistent() {
4824   int count = coarsened_count();
4825   for (int i = 0; i < count; i++) {
4826     bool unbalanced = false;
4827     bool modified = false; // track locks kind modifications
4828     Lock_List* locks_list = (Lock_List*)_coarsened_locks.at(i);
4829     uint size = locks_list->size();
4830     if (size == 0) {
4831       unbalanced = false; // All locks were eliminated - good
4832     } else if (size != locks_list->origin_cnt()) {
4833       unbalanced = true; // Some locks were removed from list
4834     } else {
4835       for (uint j = 0; j < size; j++) {
4836         Node* lock = locks_list->at(j);
4837         // All nodes in group should have the same state (modified or not)
4838         if (!lock->as_AbstractLock()->is_coarsened()) {
4839           if (j == 0) {
4840             // first on list was modified, the rest should be too for consistency
4841             modified = true;
4842           } else if (!modified) {
4843             // this lock was modified but previous locks on the list were not
4844             unbalanced = true;
4845             break;
4846           }
4847         } else if (modified) {
4848           // previous locks on list were modified but not this lock
4849           unbalanced = true;
4850           break;
4851         }
4852       }
4853     }
4854     if (unbalanced) {
4855       // unbalanced monitor enter/exit - only some [un]lock nodes were removed or modified
4856 #ifdef ASSERT
4857       if (PrintEliminateLocks) {
4858         tty->print_cr("=== unbalanced coarsened locks ===");
4859         for (uint l = 0; l < size; l++) {
4860           locks_list->at(l)->dump();
4861         }
4862       }
4863 #endif
4864       record_failure(C2Compiler::retry_no_locks_coarsening());
4865       return false;
4866     }
4867   }
4868   return true;
4869 }
4870 
4871 /**
4872  * Remove the speculative part of types and clean up the graph
4873  */
4874 void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
4875   if (UseTypeSpeculation) {
4876     Unique_Node_List worklist;
4877     worklist.push(root());
4878     int modified = 0;
4879     // Go over all type nodes that carry a speculative type, drop the
4880     // speculative part of the type and enqueue the node for an igvn
4881     // which may optimize it out.
4882     for (uint next = 0; next < worklist.size(); ++next) {
4883       Node *n  = worklist.at(next);
4884       if (n->is_Type()) {
4885         TypeNode* tn = n->as_Type();
4886         const Type* t = tn->type();
4887         const Type* t_no_spec = t->remove_speculative();
4888         if (t_no_spec != t) {
4889           bool in_hash = igvn.hash_delete(n);
4890           assert(in_hash, "node should be in igvn hash table");
4891           tn->set_type(t_no_spec);
4892           igvn.hash_insert(n);
4893           igvn._worklist.push(n); // give it a chance to go away
4894           modified++;
4895         }
4896       }
4897       // Iterate over outs - endless loops is unreachable from below
4898       for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
4899         Node *m = n->fast_out(i);
4900         if (not_a_node(m)) {
4901           continue;
4902         }
4903         worklist.push(m);
4904       }
4905     }
4906     // Drop the speculative part of all types in the igvn's type table
4907     igvn.remove_speculative_types();
4908     if (modified > 0) {
4909       igvn.optimize();
4910     }
4911 #ifdef ASSERT
4912     // Verify that after the IGVN is over no speculative type has resurfaced
4913     worklist.clear();
4914     worklist.push(root());
4915     for (uint next = 0; next < worklist.size(); ++next) {
4916       Node *n  = worklist.at(next);
4917       const Type* t = igvn.type_or_null(n);
4918       assert((t == nullptr) || (t == t->remove_speculative()), "no more speculative types");
4919       if (n->is_Type()) {
4920         t = n->as_Type()->type();
4921         assert(t == t->remove_speculative(), "no more speculative types");
4922       }
4923       // Iterate over outs - endless loops is unreachable from below
4924       for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
4925         Node *m = n->fast_out(i);
4926         if (not_a_node(m)) {
4927           continue;
4928         }
4929         worklist.push(m);
4930       }
4931     }
4932     igvn.check_no_speculative_types();
4933 #endif
4934   }
4935 }
4936 
4937 // Auxiliary methods to support randomized stressing/fuzzing.
4938 
4939 int Compile::random() {
4940   _stress_seed = os::next_random(_stress_seed);
4941   return static_cast<int>(_stress_seed);
4942 }
4943 
4944 // This method can be called the arbitrary number of times, with current count
4945 // as the argument. The logic allows selecting a single candidate from the
4946 // running list of candidates as follows:
4947 //    int count = 0;
4948 //    Cand* selected = null;
4949 //    while(cand = cand->next()) {
4950 //      if (randomized_select(++count)) {
4951 //        selected = cand;
4952 //      }
4953 //    }
4954 //
4955 // Including count equalizes the chances any candidate is "selected".
4956 // This is useful when we don't have the complete list of candidates to choose
4957 // from uniformly. In this case, we need to adjust the randomicity of the
4958 // selection, or else we will end up biasing the selection towards the latter
4959 // candidates.
4960 //
4961 // Quick back-envelope calculation shows that for the list of n candidates
4962 // the equal probability for the candidate to persist as "best" can be
4963 // achieved by replacing it with "next" k-th candidate with the probability
4964 // of 1/k. It can be easily shown that by the end of the run, the
4965 // probability for any candidate is converged to 1/n, thus giving the
4966 // uniform distribution among all the candidates.
4967 //
4968 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
4969 #define RANDOMIZED_DOMAIN_POW 29
4970 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
4971 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
4972 bool Compile::randomized_select(int count) {
4973   assert(count > 0, "only positive");
4974   return (random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);
4975 }
4976 
4977 CloneMap&     Compile::clone_map()                 { return _clone_map; }
4978 void          Compile::set_clone_map(Dict* d)      { _clone_map._dict = d; }
4979 
4980 void NodeCloneInfo::dump() const {
4981   tty->print(" {%d:%d} ", idx(), gen());
4982 }
4983 
4984 void CloneMap::clone(Node* old, Node* nnn, int gen) {
4985   uint64_t val = value(old->_idx);
4986   NodeCloneInfo cio(val);
4987   assert(val != 0, "old node should be in the map");
4988   NodeCloneInfo cin(cio.idx(), gen + cio.gen());
4989   insert(nnn->_idx, cin.get());
4990 #ifndef PRODUCT
4991   if (is_debug()) {
4992     tty->print_cr("CloneMap::clone inserted node %d info {%d:%d} into CloneMap", nnn->_idx, cin.idx(), cin.gen());
4993   }
4994 #endif
4995 }
4996 
4997 void CloneMap::verify_insert_and_clone(Node* old, Node* nnn, int gen) {
4998   NodeCloneInfo cio(value(old->_idx));
4999   if (cio.get() == 0) {
5000     cio.set(old->_idx, 0);
5001     insert(old->_idx, cio.get());
5002 #ifndef PRODUCT
5003     if (is_debug()) {
5004       tty->print_cr("CloneMap::verify_insert_and_clone inserted node %d info {%d:%d} into CloneMap", old->_idx, cio.idx(), cio.gen());
5005     }
5006 #endif
5007   }
5008   clone(old, nnn, gen);
5009 }
5010 
5011 int CloneMap::max_gen() const {
5012   int g = 0;
5013   DictI di(_dict);
5014   for(; di.test(); ++di) {
5015     int t = gen(di._key);
5016     if (g < t) {
5017       g = t;
5018 #ifndef PRODUCT
5019       if (is_debug()) {
5020         tty->print_cr("CloneMap::max_gen() update max=%d from %d", g, _2_node_idx_t(di._key));
5021       }
5022 #endif
5023     }
5024   }
5025   return g;
5026 }
5027 
5028 void CloneMap::dump(node_idx_t key) const {
5029   uint64_t val = value(key);
5030   if (val != 0) {
5031     NodeCloneInfo ni(val);
5032     ni.dump();
5033   }
5034 }
5035 
5036 // Move Allocate nodes to the start of the list
5037 void Compile::sort_macro_nodes() {
5038   int count = macro_count();
5039   int allocates = 0;
5040   for (int i = 0; i < count; i++) {
5041     Node* n = macro_node(i);
5042     if (n->is_Allocate()) {
5043       if (i != allocates) {
5044         Node* tmp = macro_node(allocates);
5045         _macro_nodes.at_put(allocates, n);
5046         _macro_nodes.at_put(i, tmp);
5047       }
5048       allocates++;
5049     }
5050   }
5051 }
5052 
5053 void Compile::print_method(CompilerPhaseType cpt, int level, Node* n) {
5054   EventCompilerPhase event;
5055   if (event.should_commit()) {
5056     CompilerEvent::PhaseEvent::post(event, C->_latest_stage_start_counter, cpt, C->_compile_id, level);
5057   }
5058 #ifndef PRODUCT
5059   ResourceMark rm;
5060   stringStream ss;
5061   ss.print_raw(CompilerPhaseTypeHelper::to_description(cpt));
5062   if (n != nullptr) {
5063     ss.print(": %d %s ", n->_idx, NodeClassNames[n->Opcode()]);
5064   }
5065 
5066   const char* name = ss.as_string();
5067   if (should_print_igv(level)) {
5068     _igv_printer->print_method(name, level);
5069   }
5070   if (should_print_phase(cpt)) {
5071     print_ideal_ir(CompilerPhaseTypeHelper::to_name(cpt));
5072   }
5073 #endif
5074   C->_latest_stage_start_counter.stamp();
5075 }
5076 
5077 // Only used from CompileWrapper
5078 void Compile::begin_method() {
5079 #ifndef PRODUCT
5080   if (_method != nullptr && should_print_igv(1)) {
5081     _igv_printer->begin_method();
5082   }
5083 #endif
5084   C->_latest_stage_start_counter.stamp();
5085 }
5086 
5087 // Only used from CompileWrapper
5088 void Compile::end_method() {
5089   EventCompilerPhase event;
5090   if (event.should_commit()) {
5091     CompilerEvent::PhaseEvent::post(event, C->_latest_stage_start_counter, PHASE_END, C->_compile_id, 1);
5092   }
5093 
5094 #ifndef PRODUCT
5095   if (_method != nullptr && should_print_igv(1)) {
5096     _igv_printer->end_method();
5097   }
5098 #endif
5099 }
5100 
5101 bool Compile::should_print_phase(CompilerPhaseType cpt) {
5102 #ifndef PRODUCT
5103   if ((_directive->ideal_phase_mask() & CompilerPhaseTypeHelper::to_bitmask(cpt)) != 0) {
5104     return true;
5105   }
5106 #endif
5107   return false;
5108 }
5109 
5110 bool Compile::should_print_igv(int level) {
5111 #ifndef PRODUCT
5112   if (PrintIdealGraphLevel < 0) { // disabled by the user
5113     return false;
5114   }
5115 
5116   bool need = directive()->IGVPrintLevelOption >= level;
5117   if (need && !_igv_printer) {
5118     _igv_printer = IdealGraphPrinter::printer();
5119     _igv_printer->set_compile(this);
5120   }
5121   return need;
5122 #else
5123   return false;
5124 #endif
5125 }
5126 
5127 #ifndef PRODUCT
5128 IdealGraphPrinter* Compile::_debug_file_printer = nullptr;
5129 IdealGraphPrinter* Compile::_debug_network_printer = nullptr;
5130 
5131 // Called from debugger. Prints method to the default file with the default phase name.
5132 // This works regardless of any Ideal Graph Visualizer flags set or not.
5133 void igv_print() {
5134   Compile::current()->igv_print_method_to_file();
5135 }
5136 
5137 // Same as igv_print() above but with a specified phase name.
5138 void igv_print(const char* phase_name) {
5139   Compile::current()->igv_print_method_to_file(phase_name);
5140 }
5141 
5142 // Called from debugger. Prints method with the default phase name to the default network or the one specified with
5143 // the network flags for the Ideal Graph Visualizer, or to the default file depending on the 'network' argument.
5144 // This works regardless of any Ideal Graph Visualizer flags set or not.
5145 void igv_print(bool network) {
5146   if (network) {
5147     Compile::current()->igv_print_method_to_network();
5148   } else {
5149     Compile::current()->igv_print_method_to_file();
5150   }
5151 }
5152 
5153 // Same as igv_print(bool network) above but with a specified phase name.
5154 void igv_print(bool network, const char* phase_name) {
5155   if (network) {
5156     Compile::current()->igv_print_method_to_network(phase_name);
5157   } else {
5158     Compile::current()->igv_print_method_to_file(phase_name);
5159   }
5160 }
5161 
5162 // Called from debugger. Normal write to the default _printer. Only works if Ideal Graph Visualizer printing flags are set.
5163 void igv_print_default() {
5164   Compile::current()->print_method(PHASE_DEBUG, 0);
5165 }
5166 
5167 // Called from debugger, especially when replaying a trace in which the program state cannot be altered like with rr replay.
5168 // A method is appended to an existing default file with the default phase name. This means that igv_append() must follow
5169 // an earlier igv_print(*) call which sets up the file. This works regardless of any Ideal Graph Visualizer flags set or not.
5170 void igv_append() {
5171   Compile::current()->igv_print_method_to_file("Debug", true);
5172 }
5173 
5174 // Same as igv_append() above but with a specified phase name.
5175 void igv_append(const char* phase_name) {
5176   Compile::current()->igv_print_method_to_file(phase_name, true);
5177 }
5178 
5179 void Compile::igv_print_method_to_file(const char* phase_name, bool append) {
5180   const char* file_name = "custom_debug.xml";
5181   if (_debug_file_printer == nullptr) {
5182     _debug_file_printer = new IdealGraphPrinter(C, file_name, append);
5183   } else {
5184     _debug_file_printer->update_compiled_method(C->method());
5185   }
5186   tty->print_cr("Method %s to %s", append ? "appended" : "printed", file_name);
5187   _debug_file_printer->print(phase_name, (Node*)C->root());
5188 }
5189 
5190 void Compile::igv_print_method_to_network(const char* phase_name) {
5191   if (_debug_network_printer == nullptr) {
5192     _debug_network_printer = new IdealGraphPrinter(C);
5193   } else {
5194     _debug_network_printer->update_compiled_method(C->method());
5195   }
5196   tty->print_cr("Method printed over network stream to IGV");
5197   _debug_network_printer->print(phase_name, (Node*)C->root());
5198 }
5199 #endif
5200 
5201 Node* Compile::narrow_value(BasicType bt, Node* value, const Type* type, PhaseGVN* phase, bool transform_res) {
5202   if (type != nullptr && phase->type(value)->higher_equal(type)) {
5203     return value;
5204   }
5205   Node* result = nullptr;
5206   if (bt == T_BYTE) {
5207     result = phase->transform(new LShiftINode(value, phase->intcon(24)));
5208     result = new RShiftINode(result, phase->intcon(24));
5209   } else if (bt == T_BOOLEAN) {
5210     result = new AndINode(value, phase->intcon(0xFF));
5211   } else if (bt == T_CHAR) {
5212     result = new AndINode(value,phase->intcon(0xFFFF));
5213   } else {
5214     assert(bt == T_SHORT, "unexpected narrow type");
5215     result = phase->transform(new LShiftINode(value, phase->intcon(16)));
5216     result = new RShiftINode(result, phase->intcon(16));
5217   }
5218   if (transform_res) {
5219     result = phase->transform(result);
5220   }
5221   return result;
5222 }
5223