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