1 /*
   2  * Copyright (c) 2001, 2026, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "asm/register.hpp"
  26 #include "ci/ciObjArray.hpp"
  27 #include "ci/ciUtilities.hpp"
  28 #include "classfile/javaClasses.hpp"
  29 #include "compiler/compileLog.hpp"
  30 #include "gc/shared/barrierSet.hpp"
  31 #include "gc/shared/c2/barrierSetC2.hpp"
  32 #include "interpreter/interpreter.hpp"
  33 #include "memory/resourceArea.hpp"
  34 #include "opto/addnode.hpp"
  35 #include "opto/castnode.hpp"
  36 #include "opto/convertnode.hpp"
  37 #include "opto/graphKit.hpp"
  38 #include "opto/idealKit.hpp"
  39 #include "opto/intrinsicnode.hpp"
  40 #include "opto/locknode.hpp"
  41 #include "opto/machnode.hpp"
  42 #include "opto/opaquenode.hpp"
  43 #include "opto/parse.hpp"
  44 #include "opto/rootnode.hpp"
  45 #include "opto/runtime.hpp"
  46 #include "opto/subtypenode.hpp"
  47 #include "runtime/deoptimization.hpp"
  48 #include "runtime/sharedRuntime.hpp"
  49 #include "utilities/bitMap.inline.hpp"
  50 #include "utilities/growableArray.hpp"
  51 #include "utilities/powerOfTwo.hpp"
  52 
  53 //----------------------------GraphKit-----------------------------------------
  54 // Main utility constructor.
  55 GraphKit::GraphKit(JVMState* jvms)
  56   : Phase(Phase::Parser),
  57     _env(C->env()),
  58     _gvn(*C->initial_gvn()),
  59     _barrier_set(BarrierSet::barrier_set()->barrier_set_c2())
  60 {
  61   _exceptions = jvms->map()->next_exception();
  62   if (_exceptions != nullptr)  jvms->map()->set_next_exception(nullptr);
  63   set_jvms(jvms);
  64 }
  65 
  66 // Private constructor for parser.
  67 GraphKit::GraphKit()
  68   : Phase(Phase::Parser),
  69     _env(C->env()),
  70     _gvn(*C->initial_gvn()),
  71     _barrier_set(BarrierSet::barrier_set()->barrier_set_c2())
  72 {
  73   _exceptions = nullptr;
  74   set_map(nullptr);
  75   DEBUG_ONLY(_sp = -99);
  76   DEBUG_ONLY(set_bci(-99));
  77 }
  78 
  79 
  80 
  81 //---------------------------clean_stack---------------------------------------
  82 // Clear away rubbish from the stack area of the JVM state.
  83 // This destroys any arguments that may be waiting on the stack.
  84 void GraphKit::clean_stack(int from_sp) {
  85   SafePointNode* map      = this->map();
  86   JVMState*      jvms     = this->jvms();
  87   int            stk_size = jvms->stk_size();
  88   int            stkoff   = jvms->stkoff();
  89   Node*          top      = this->top();
  90   for (int i = from_sp; i < stk_size; i++) {
  91     if (map->in(stkoff + i) != top) {
  92       map->set_req(stkoff + i, top);
  93     }
  94   }
  95 }
  96 
  97 
  98 //--------------------------------sync_jvms-----------------------------------
  99 // Make sure our current jvms agrees with our parse state.
 100 JVMState* GraphKit::sync_jvms() const {
 101   JVMState* jvms = this->jvms();
 102   jvms->set_bci(bci());       // Record the new bci in the JVMState
 103   jvms->set_sp(sp());         // Record the new sp in the JVMState
 104   assert(jvms_in_sync(), "jvms is now in sync");
 105   return jvms;
 106 }
 107 
 108 //--------------------------------sync_jvms_for_reexecute---------------------
 109 // Make sure our current jvms agrees with our parse state.  This version
 110 // uses the reexecute_sp for reexecuting bytecodes.
 111 JVMState* GraphKit::sync_jvms_for_reexecute() {
 112   JVMState* jvms = this->jvms();
 113   jvms->set_bci(bci());          // Record the new bci in the JVMState
 114   jvms->set_sp(reexecute_sp());  // Record the new sp in the JVMState
 115   return jvms;
 116 }
 117 
 118 #ifdef ASSERT
 119 bool GraphKit::jvms_in_sync() const {
 120   Parse* parse = is_Parse();
 121   if (parse == nullptr) {
 122     if (bci() !=      jvms()->bci())          return false;
 123     if (sp()  != (int)jvms()->sp())           return false;
 124     return true;
 125   }
 126   if (jvms()->method() != parse->method())    return false;
 127   if (jvms()->bci()    != parse->bci())       return false;
 128   int jvms_sp = jvms()->sp();
 129   if (jvms_sp          != parse->sp())        return false;
 130   int jvms_depth = jvms()->depth();
 131   if (jvms_depth       != parse->depth())     return false;
 132   return true;
 133 }
 134 
 135 // Local helper checks for special internal merge points
 136 // used to accumulate and merge exception states.
 137 // They are marked by the region's in(0) edge being the map itself.
 138 // Such merge points must never "escape" into the parser at large,
 139 // until they have been handed to gvn.transform.
 140 static bool is_hidden_merge(Node* reg) {
 141   if (reg == nullptr)  return false;
 142   if (reg->is_Phi()) {
 143     reg = reg->in(0);
 144     if (reg == nullptr)  return false;
 145   }
 146   return reg->is_Region() && reg->in(0) != nullptr && reg->in(0)->is_Root();
 147 }
 148 
 149 void GraphKit::verify_map() const {
 150   if (map() == nullptr)  return;  // null map is OK
 151   assert(map()->req() <= jvms()->endoff(), "no extra garbage on map");
 152   assert(!map()->has_exceptions(),    "call add_exception_states_from 1st");
 153   assert(!is_hidden_merge(control()), "call use_exception_state, not set_map");
 154 }
 155 
 156 void GraphKit::verify_exception_state(SafePointNode* ex_map) {
 157   assert(ex_map->next_exception() == nullptr, "not already part of a chain");
 158   assert(has_saved_ex_oop(ex_map), "every exception state has an ex_oop");
 159 }
 160 #endif
 161 
 162 //---------------------------stop_and_kill_map---------------------------------
 163 // Set _map to null, signalling a stop to further bytecode execution.
 164 // First smash the current map's control to a constant, to mark it dead.
 165 void GraphKit::stop_and_kill_map() {
 166   SafePointNode* dead_map = stop();
 167   if (dead_map != nullptr) {
 168     dead_map->disconnect_inputs(C); // Mark the map as killed.
 169     assert(dead_map->is_killed(), "must be so marked");
 170   }
 171 }
 172 
 173 
 174 //--------------------------------stopped--------------------------------------
 175 // Tell if _map is null, or control is top.
 176 bool GraphKit::stopped() {
 177   if (map() == nullptr)        return true;
 178   else if (control() == top()) return true;
 179   else                         return false;
 180 }
 181 
 182 
 183 //-----------------------------has_exception_handler----------------------------------
 184 // Tell if this method or any caller method has exception handlers.
 185 bool GraphKit::has_exception_handler() {
 186   for (JVMState* jvmsp = jvms(); jvmsp != nullptr; jvmsp = jvmsp->caller()) {
 187     if (jvmsp->has_method() && jvmsp->method()->has_exception_handlers()) {
 188       return true;
 189     }
 190   }
 191   return false;
 192 }
 193 
 194 //------------------------------save_ex_oop------------------------------------
 195 // Save an exception without blowing stack contents or other JVM state.
 196 void GraphKit::set_saved_ex_oop(SafePointNode* ex_map, Node* ex_oop) {
 197   assert(!has_saved_ex_oop(ex_map), "clear ex-oop before setting again");
 198   ex_map->add_req(ex_oop);
 199   DEBUG_ONLY(verify_exception_state(ex_map));
 200 }
 201 
 202 inline static Node* common_saved_ex_oop(SafePointNode* ex_map, bool clear_it) {
 203   assert(GraphKit::has_saved_ex_oop(ex_map), "ex_oop must be there");
 204   Node* ex_oop = ex_map->in(ex_map->req()-1);
 205   if (clear_it)  ex_map->del_req(ex_map->req()-1);
 206   return ex_oop;
 207 }
 208 
 209 //-----------------------------saved_ex_oop------------------------------------
 210 // Recover a saved exception from its map.
 211 Node* GraphKit::saved_ex_oop(SafePointNode* ex_map) {
 212   return common_saved_ex_oop(ex_map, false);
 213 }
 214 
 215 //--------------------------clear_saved_ex_oop---------------------------------
 216 // Erase a previously saved exception from its map.
 217 Node* GraphKit::clear_saved_ex_oop(SafePointNode* ex_map) {
 218   return common_saved_ex_oop(ex_map, true);
 219 }
 220 
 221 #ifdef ASSERT
 222 //---------------------------has_saved_ex_oop----------------------------------
 223 // Erase a previously saved exception from its map.
 224 bool GraphKit::has_saved_ex_oop(SafePointNode* ex_map) {
 225   return ex_map->req() == ex_map->jvms()->endoff()+1;
 226 }
 227 #endif
 228 
 229 //-------------------------make_exception_state--------------------------------
 230 // Turn the current JVM state into an exception state, appending the ex_oop.
 231 SafePointNode* GraphKit::make_exception_state(Node* ex_oop) {
 232   sync_jvms();
 233   SafePointNode* ex_map = stop();  // do not manipulate this map any more
 234   set_saved_ex_oop(ex_map, ex_oop);
 235   return ex_map;
 236 }
 237 
 238 
 239 //--------------------------add_exception_state--------------------------------
 240 // Add an exception to my list of exceptions.
 241 void GraphKit::add_exception_state(SafePointNode* ex_map) {
 242   if (ex_map == nullptr || ex_map->control() == top()) {
 243     return;
 244   }
 245 #ifdef ASSERT
 246   verify_exception_state(ex_map);
 247   if (has_exceptions()) {
 248     assert(ex_map->jvms()->same_calls_as(_exceptions->jvms()), "all collected exceptions must come from the same place");
 249   }
 250 #endif
 251 
 252   // If there is already an exception of exactly this type, merge with it.
 253   // In particular, null-checks and other low-level exceptions common up here.
 254   Node*       ex_oop  = saved_ex_oop(ex_map);
 255   const Type* ex_type = _gvn.type(ex_oop);
 256   if (ex_oop == top()) {
 257     // No action needed.
 258     return;
 259   }
 260   assert(ex_type->isa_instptr(), "exception must be an instance");
 261   for (SafePointNode* e2 = _exceptions; e2 != nullptr; e2 = e2->next_exception()) {
 262     const Type* ex_type2 = _gvn.type(saved_ex_oop(e2));
 263     // We check sp also because call bytecodes can generate exceptions
 264     // both before and after arguments are popped!
 265     if (ex_type2 == ex_type
 266         && e2->_jvms->sp() == ex_map->_jvms->sp()) {
 267       combine_exception_states(ex_map, e2);
 268       return;
 269     }
 270   }
 271 
 272   // No pre-existing exception of the same type.  Chain it on the list.
 273   push_exception_state(ex_map);
 274 }
 275 
 276 //-----------------------add_exception_states_from-----------------------------
 277 void GraphKit::add_exception_states_from(JVMState* jvms) {
 278   SafePointNode* ex_map = jvms->map()->next_exception();
 279   if (ex_map != nullptr) {
 280     jvms->map()->set_next_exception(nullptr);
 281     for (SafePointNode* next_map; ex_map != nullptr; ex_map = next_map) {
 282       next_map = ex_map->next_exception();
 283       ex_map->set_next_exception(nullptr);
 284       add_exception_state(ex_map);
 285     }
 286   }
 287 }
 288 
 289 //-----------------------transfer_exceptions_into_jvms-------------------------
 290 JVMState* GraphKit::transfer_exceptions_into_jvms() {
 291   if (map() == nullptr) {
 292     // We need a JVMS to carry the exceptions, but the map has gone away.
 293     // Create a scratch JVMS, cloned from any of the exception states...
 294     if (has_exceptions()) {
 295       _map = _exceptions;
 296       _map = clone_map();
 297       _map->set_next_exception(nullptr);
 298       clear_saved_ex_oop(_map);
 299       DEBUG_ONLY(verify_map());
 300     } else {
 301       // ...or created from scratch
 302       JVMState* jvms = new (C) JVMState(_method, nullptr);
 303       jvms->set_bci(_bci);
 304       jvms->set_sp(_sp);
 305       jvms->set_map(new SafePointNode(TypeFunc::Parms, jvms));
 306       set_jvms(jvms);
 307       for (uint i = 0; i < map()->req(); i++)  map()->init_req(i, top());
 308       set_all_memory(top());
 309       while (map()->req() < jvms->endoff())  map()->add_req(top());
 310     }
 311     // (This is a kludge, in case you didn't notice.)
 312     set_control(top());
 313   }
 314   JVMState* jvms = sync_jvms();
 315   assert(!jvms->map()->has_exceptions(), "no exceptions on this map yet");
 316   jvms->map()->set_next_exception(_exceptions);
 317   _exceptions = nullptr;   // done with this set of exceptions
 318   return jvms;
 319 }
 320 
 321 static inline void add_n_reqs(Node* dstphi, Node* srcphi) {
 322   assert(is_hidden_merge(dstphi), "must be a special merge node");
 323   assert(is_hidden_merge(srcphi), "must be a special merge node");
 324   uint limit = srcphi->req();
 325   for (uint i = PhiNode::Input; i < limit; i++) {
 326     dstphi->add_req(srcphi->in(i));
 327   }
 328 }
 329 static inline void add_one_req(Node* dstphi, Node* src) {
 330   assert(is_hidden_merge(dstphi), "must be a special merge node");
 331   assert(!is_hidden_merge(src), "must not be a special merge node");
 332   dstphi->add_req(src);
 333 }
 334 
 335 //-----------------------combine_exception_states------------------------------
 336 // This helper function combines exception states by building phis on a
 337 // specially marked state-merging region.  These regions and phis are
 338 // untransformed, and can build up gradually.  The region is marked by
 339 // having a control input of its exception map, rather than null.  Such
 340 // regions do not appear except in this function, and in use_exception_state.
 341 void GraphKit::combine_exception_states(SafePointNode* ex_map, SafePointNode* phi_map) {
 342   if (failing_internal()) {
 343     return;  // dying anyway...
 344   }
 345   JVMState* ex_jvms = ex_map->_jvms;
 346   assert(ex_jvms->same_calls_as(phi_map->_jvms), "consistent call chains");
 347   assert(ex_jvms->stkoff() == phi_map->_jvms->stkoff(), "matching locals");
 348   assert(ex_jvms->sp() == phi_map->_jvms->sp(), "matching stack sizes");
 349   assert(ex_jvms->monoff() == phi_map->_jvms->monoff(), "matching JVMS");
 350   assert(ex_jvms->scloff() == phi_map->_jvms->scloff(), "matching scalar replaced objects");
 351   assert(ex_map->req() == phi_map->req(), "matching maps");
 352   uint tos = ex_jvms->stkoff() + ex_jvms->sp();
 353   Node*         hidden_merge_mark = root();
 354   Node*         region  = phi_map->control();
 355   MergeMemNode* phi_mem = phi_map->merged_memory();
 356   MergeMemNode* ex_mem  = ex_map->merged_memory();
 357   if (region->in(0) != hidden_merge_mark) {
 358     // The control input is not (yet) a specially-marked region in phi_map.
 359     // Make it so, and build some phis.
 360     region = new RegionNode(2);
 361     _gvn.set_type(region, Type::CONTROL);
 362     region->set_req(0, hidden_merge_mark);  // marks an internal ex-state
 363     region->init_req(1, phi_map->control());
 364     phi_map->set_control(region);
 365     Node* io_phi = PhiNode::make(region, phi_map->i_o(), Type::ABIO);
 366     record_for_igvn(io_phi);
 367     _gvn.set_type(io_phi, Type::ABIO);
 368     phi_map->set_i_o(io_phi);
 369     for (MergeMemStream mms(phi_mem); mms.next_non_empty(); ) {
 370       Node* m = mms.memory();
 371       Node* m_phi = PhiNode::make(region, m, Type::MEMORY, mms.adr_type(C));
 372       record_for_igvn(m_phi);
 373       _gvn.set_type(m_phi, Type::MEMORY);
 374       mms.set_memory(m_phi);
 375     }
 376   }
 377 
 378   // Either or both of phi_map and ex_map might already be converted into phis.
 379   Node* ex_control = ex_map->control();
 380   // if there is special marking on ex_map also, we add multiple edges from src
 381   bool add_multiple = (ex_control->in(0) == hidden_merge_mark);
 382   // how wide was the destination phi_map, originally?
 383   uint orig_width = region->req();
 384 
 385   if (add_multiple) {
 386     add_n_reqs(region, ex_control);
 387     add_n_reqs(phi_map->i_o(), ex_map->i_o());
 388   } else {
 389     // ex_map has no merges, so we just add single edges everywhere
 390     add_one_req(region, ex_control);
 391     add_one_req(phi_map->i_o(), ex_map->i_o());
 392   }
 393   for (MergeMemStream mms(phi_mem, ex_mem); mms.next_non_empty2(); ) {
 394     if (mms.is_empty()) {
 395       // get a copy of the base memory, and patch some inputs into it
 396       const TypePtr* adr_type = mms.adr_type(C);
 397       Node* phi = mms.force_memory()->as_Phi()->slice_memory(adr_type);
 398       assert(phi->as_Phi()->region() == mms.base_memory()->in(0), "");
 399       mms.set_memory(phi);
 400       // Prepare to append interesting stuff onto the newly sliced phi:
 401       while (phi->req() > orig_width)  phi->del_req(phi->req()-1);
 402     }
 403     // Append stuff from ex_map:
 404     if (add_multiple) {
 405       add_n_reqs(mms.memory(), mms.memory2());
 406     } else {
 407       add_one_req(mms.memory(), mms.memory2());
 408     }
 409   }
 410   uint limit = ex_map->req();
 411   for (uint i = TypeFunc::Parms; i < limit; i++) {
 412     // Skip everything in the JVMS after tos.  (The ex_oop follows.)
 413     if (i == tos)  i = ex_jvms->monoff();
 414     Node* src = ex_map->in(i);
 415     Node* dst = phi_map->in(i);
 416     if (src != dst) {
 417       PhiNode* phi;
 418       if (dst->in(0) != region) {
 419         dst = phi = PhiNode::make(region, dst, _gvn.type(dst));
 420         record_for_igvn(phi);
 421         _gvn.set_type(phi, phi->type());
 422         phi_map->set_req(i, dst);
 423         // Prepare to append interesting stuff onto the new phi:
 424         while (dst->req() > orig_width)  dst->del_req(dst->req()-1);
 425       } else {
 426         assert(dst->is_Phi(), "nobody else uses a hidden region");
 427         phi = dst->as_Phi();
 428       }
 429       if (add_multiple && src->in(0) == ex_control) {
 430         // Both are phis.
 431         add_n_reqs(dst, src);
 432       } else {
 433         while (dst->req() < region->req())  add_one_req(dst, src);
 434       }
 435       const Type* srctype = _gvn.type(src);
 436       if (phi->type() != srctype) {
 437         const Type* dsttype = phi->type()->meet_speculative(srctype);
 438         if (phi->type() != dsttype) {
 439           phi->set_type(dsttype);
 440           _gvn.set_type(phi, dsttype);
 441         }
 442       }
 443     }
 444   }
 445   phi_map->merge_replaced_nodes_with(ex_map);
 446 }
 447 
 448 //--------------------------use_exception_state--------------------------------
 449 Node* GraphKit::use_exception_state(SafePointNode* phi_map) {
 450   if (failing_internal()) { stop(); return top(); }
 451   Node* region = phi_map->control();
 452   Node* hidden_merge_mark = root();
 453   assert(phi_map->jvms()->map() == phi_map, "sanity: 1-1 relation");
 454   Node* ex_oop = clear_saved_ex_oop(phi_map);
 455   if (region->in(0) == hidden_merge_mark) {
 456     // Special marking for internal ex-states.  Process the phis now.
 457     region->set_req(0, region);  // now it's an ordinary region
 458     set_jvms(phi_map->jvms());   // ...so now we can use it as a map
 459     // Note: Setting the jvms also sets the bci and sp.
 460     set_control(_gvn.transform(region));
 461     uint tos = jvms()->stkoff() + sp();
 462     for (uint i = 1; i < tos; i++) {
 463       Node* x = phi_map->in(i);
 464       if (x->in(0) == region) {
 465         assert(x->is_Phi(), "expected a special phi");
 466         phi_map->set_req(i, _gvn.transform(x));
 467       }
 468     }
 469     for (MergeMemStream mms(merged_memory()); mms.next_non_empty(); ) {
 470       Node* x = mms.memory();
 471       if (x->in(0) == region) {
 472         assert(x->is_Phi(), "nobody else uses a hidden region");
 473         mms.set_memory(_gvn.transform(x));
 474       }
 475     }
 476     if (ex_oop->in(0) == region) {
 477       assert(ex_oop->is_Phi(), "expected a special phi");
 478       ex_oop = _gvn.transform(ex_oop);
 479     }
 480   } else {
 481     set_jvms(phi_map->jvms());
 482   }
 483 
 484   assert(!is_hidden_merge(phi_map->control()), "hidden ex. states cleared");
 485   assert(!is_hidden_merge(phi_map->i_o()), "hidden ex. states cleared");
 486   return ex_oop;
 487 }
 488 
 489 //---------------------------------java_bc-------------------------------------
 490 Bytecodes::Code GraphKit::java_bc() const {
 491   ciMethod* method = this->method();
 492   int       bci    = this->bci();
 493   if (method != nullptr && bci != InvocationEntryBci)
 494     return method->java_code_at_bci(bci);
 495   else
 496     return Bytecodes::_illegal;
 497 }
 498 
 499 void GraphKit::uncommon_trap_if_should_post_on_exceptions(Deoptimization::DeoptReason reason,
 500                                                           bool must_throw) {
 501     // if the exception capability is set, then we will generate code
 502     // to check the JavaThread.should_post_on_exceptions flag to see
 503     // if we actually need to report exception events (for this
 504     // thread).  If we don't need to report exception events, we will
 505     // take the normal fast path provided by add_exception_events.  If
 506     // exception event reporting is enabled for this thread, we will
 507     // take the uncommon_trap in the BuildCutout below.
 508 
 509     // first must access the should_post_on_exceptions_flag in this thread's JavaThread
 510     Node* jthread = _gvn.transform(new ThreadLocalNode());
 511     Node* adr = basic_plus_adr(top(), jthread, in_bytes(JavaThread::should_post_on_exceptions_flag_offset()));
 512     Node* should_post_flag = make_load(control(), adr, TypeInt::INT, T_INT, MemNode::unordered);
 513 
 514     // Test the should_post_on_exceptions_flag vs. 0
 515     Node* chk = _gvn.transform( new CmpINode(should_post_flag, intcon(0)) );
 516     Node* tst = _gvn.transform( new BoolNode(chk, BoolTest::eq) );
 517 
 518     // Branch to slow_path if should_post_on_exceptions_flag was true
 519     { BuildCutout unless(this, tst, PROB_MAX);
 520       // Do not try anything fancy if we're notifying the VM on every throw.
 521       // Cf. case Bytecodes::_athrow in parse2.cpp.
 522       uncommon_trap(reason, Deoptimization::Action_none,
 523                     (ciKlass*)nullptr, (char*)nullptr, must_throw);
 524     }
 525 
 526 }
 527 
 528 //------------------------------builtin_throw----------------------------------
 529 void GraphKit::builtin_throw(Deoptimization::DeoptReason reason) {
 530   builtin_throw(reason, builtin_throw_exception(reason), /*allow_too_many_traps*/ true);
 531 }
 532 
 533 void GraphKit::builtin_throw(Deoptimization::DeoptReason reason,
 534                              ciInstance* ex_obj,
 535                              bool allow_too_many_traps) {
 536   // If this throw happens frequently, an uncommon trap might cause
 537   // a performance pothole.  If there is a local exception handler,
 538   // and if this particular bytecode appears to be deoptimizing often,
 539   // let us handle the throw inline, with a preconstructed instance.
 540   // Note:   If the deopt count has blown up, the uncommon trap
 541   // runtime is going to flush this nmethod, not matter what.
 542   if (is_builtin_throw_hot(reason)) {
 543     if (method()->can_omit_stack_trace() && ex_obj != nullptr) {
 544       // If the throw is local, we use a pre-existing instance and
 545       // punt on the backtrace.  This would lead to a missing backtrace
 546       // (a repeat of 4292742) if the backtrace object is ever asked
 547       // for its backtrace.
 548       // Fixing this remaining case of 4292742 requires some flavor of
 549       // escape analysis.  Leave that for the future.
 550       if (env()->jvmti_can_post_on_exceptions()) {
 551         // check if we must post exception events, take uncommon trap if so
 552         uncommon_trap_if_should_post_on_exceptions(reason, true /*must_throw*/);
 553         // here if should_post_on_exceptions is false
 554         // continue on with the normal codegen
 555       }
 556 
 557       // Cheat with a preallocated exception object.
 558       if (C->log() != nullptr)
 559         C->log()->elem("hot_throw preallocated='1' reason='%s'",
 560                        Deoptimization::trap_reason_name(reason));
 561       const TypeInstPtr* ex_con  = TypeInstPtr::make(ex_obj);
 562       Node*              ex_node = _gvn.transform(ConNode::make(ex_con));
 563 
 564       // Clear the detail message of the preallocated exception object.
 565       // Weblogic sometimes mutates the detail message of exceptions
 566       // using reflection.
 567       int offset = java_lang_Throwable::get_detailMessage_offset();
 568       const TypePtr* adr_typ = ex_con->add_offset(offset);
 569 
 570       Node *adr = basic_plus_adr(ex_node, ex_node, offset);
 571       const TypeOopPtr* val_type = TypeOopPtr::make_from_klass(env()->String_klass());
 572       Node *store = access_store_at(ex_node, adr, adr_typ, null(), val_type, T_OBJECT, IN_HEAP);
 573 
 574       if (!method()->has_exception_handlers()) {
 575         // We don't need to preserve the stack if there's no handler as the entire frame is going to be popped anyway.
 576         // This prevents issues with exception handling and late inlining.
 577         set_sp(0);
 578         clean_stack(0);
 579       }
 580 
 581       add_exception_state(make_exception_state(ex_node));
 582       return;
 583     } else if (builtin_throw_too_many_traps(reason, ex_obj)) {
 584       // We cannot afford to take too many traps here. Suffer in the interpreter instead.
 585       assert(allow_too_many_traps, "not allowed");
 586       if (C->log() != nullptr) {
 587         C->log()->elem("hot_throw preallocated='0' reason='%s' mcount='%d'",
 588                        Deoptimization::trap_reason_name(reason),
 589                        C->trap_count(reason));
 590       }
 591       uncommon_trap(reason, Deoptimization::Action_none,
 592                     (ciKlass*) nullptr, (char*) nullptr,
 593                     true /*must_throw*/);
 594       return;
 595     }
 596   }
 597 
 598   // %%% Maybe add entry to OptoRuntime which directly throws the exc.?
 599   // It won't be much cheaper than bailing to the interp., since we'll
 600   // have to pass up all the debug-info, and the runtime will have to
 601   // create the stack trace.
 602 
 603   // Usual case:  Bail to interpreter.
 604   // Reserve the right to recompile if we haven't seen anything yet.
 605 
 606   // "must_throw" prunes the JVM state to include only the stack, if there
 607   // are no local exception handlers.  This should cut down on register
 608   // allocation time and code size, by drastically reducing the number
 609   // of in-edges on the call to the uncommon trap.
 610   uncommon_trap(reason, Deoptimization::Action_maybe_recompile,
 611                 (ciKlass*) nullptr, (char*) nullptr,
 612                 true /*must_throw*/);
 613 }
 614 
 615 bool GraphKit::is_builtin_throw_hot(Deoptimization::DeoptReason reason) {
 616   // If this particular condition has not yet happened at this
 617   // bytecode, then use the uncommon trap mechanism, and allow for
 618   // a future recompilation if several traps occur here.
 619   // If the throw is hot, try to use a more complicated inline mechanism
 620   // which keeps execution inside the compiled code.
 621   if (ProfileTraps) {
 622     if (too_many_traps(reason)) {
 623       return true;
 624     }
 625     // (If there is no MDO at all, assume it is early in
 626     // execution, and that any deopts are part of the
 627     // startup transient, and don't need to be remembered.)
 628 
 629     // Also, if there is a local exception handler, treat all throws
 630     // as hot if there has been at least one in this method.
 631     if (C->trap_count(reason) != 0 &&
 632         method()->method_data()->trap_count(reason) != 0 &&
 633         has_exception_handler()) {
 634       return true;
 635     }
 636   }
 637   return false;
 638 }
 639 
 640 bool GraphKit::builtin_throw_too_many_traps(Deoptimization::DeoptReason reason,
 641                                             ciInstance* ex_obj) {
 642   if (is_builtin_throw_hot(reason)) {
 643     if (method()->can_omit_stack_trace() && ex_obj != nullptr) {
 644       return false; // no traps; throws preallocated exception instead
 645     }
 646     ciMethod* m = Deoptimization::reason_is_speculate(reason) ? C->method() : nullptr;
 647     if (method()->method_data()->trap_recompiled_at(bci(), m) ||
 648         C->too_many_traps(reason)) {
 649       return true;
 650     }
 651   }
 652   return false;
 653 }
 654 
 655 ciInstance* GraphKit::builtin_throw_exception(Deoptimization::DeoptReason reason) const {
 656   // Preallocated exception objects to use when we don't need the backtrace.
 657   switch (reason) {
 658   case Deoptimization::Reason_null_check:
 659     return env()->NullPointerException_instance();
 660   case Deoptimization::Reason_div0_check:
 661     return env()->ArithmeticException_instance();
 662   case Deoptimization::Reason_range_check:
 663     return env()->ArrayIndexOutOfBoundsException_instance();
 664   case Deoptimization::Reason_class_check:
 665     return env()->ClassCastException_instance();
 666   case Deoptimization::Reason_array_check:
 667     return env()->ArrayStoreException_instance();
 668   default:
 669     return nullptr;
 670   }
 671 }
 672 
 673 //----------------------------PreserveJVMState---------------------------------
 674 PreserveJVMState::PreserveJVMState(GraphKit* kit, bool clone_map) {
 675   DEBUG_ONLY(kit->verify_map());
 676   _kit    = kit;
 677   _map    = kit->map();   // preserve the map
 678   _sp     = kit->sp();
 679   kit->set_map(clone_map ? kit->clone_map() : nullptr);
 680 #ifdef ASSERT
 681   _bci    = kit->bci();
 682   Parse* parser = kit->is_Parse();
 683   int block = (parser == nullptr || parser->block() == nullptr) ? -1 : parser->block()->rpo();
 684   _block  = block;
 685 #endif
 686 }
 687 PreserveJVMState::~PreserveJVMState() {
 688   GraphKit* kit = _kit;
 689 #ifdef ASSERT
 690   assert(kit->bci() == _bci, "bci must not shift");
 691   Parse* parser = kit->is_Parse();
 692   int block = (parser == nullptr || parser->block() == nullptr) ? -1 : parser->block()->rpo();
 693   assert(block == _block,    "block must not shift");
 694 #endif
 695   kit->set_map(_map);
 696   kit->set_sp(_sp);
 697 }
 698 
 699 
 700 //-----------------------------BuildCutout-------------------------------------
 701 BuildCutout::BuildCutout(GraphKit* kit, Node* p, float prob, float cnt)
 702   : PreserveJVMState(kit)
 703 {
 704   assert(p->is_Con() || p->is_Bool(), "test must be a bool");
 705   SafePointNode* outer_map = _map;   // preserved map is caller's
 706   SafePointNode* inner_map = kit->map();
 707   IfNode* iff = kit->create_and_map_if(outer_map->control(), p, prob, cnt);
 708   outer_map->set_control(kit->gvn().transform( new IfTrueNode(iff) ));
 709   inner_map->set_control(kit->gvn().transform( new IfFalseNode(iff) ));
 710 }
 711 BuildCutout::~BuildCutout() {
 712   GraphKit* kit = _kit;
 713   assert(kit->stopped(), "cutout code must stop, throw, return, etc.");
 714 }
 715 
 716 //---------------------------PreserveReexecuteState----------------------------
 717 PreserveReexecuteState::PreserveReexecuteState(GraphKit* kit) {
 718   assert(!kit->stopped(), "must call stopped() before");
 719   _kit    =    kit;
 720   _sp     =    kit->sp();
 721   _reexecute = kit->jvms()->_reexecute;
 722 }
 723 PreserveReexecuteState::~PreserveReexecuteState() {
 724   if (_kit->stopped()) return;
 725   _kit->jvms()->_reexecute = _reexecute;
 726   _kit->set_sp(_sp);
 727 }
 728 
 729 //------------------------------clone_map--------------------------------------
 730 // Implementation of PreserveJVMState
 731 //
 732 // Only clone_map(...) here. If this function is only used in the
 733 // PreserveJVMState class we may want to get rid of this extra
 734 // function eventually and do it all there.
 735 
 736 SafePointNode* GraphKit::clone_map() {
 737   if (map() == nullptr)  return nullptr;
 738 
 739   // Clone the memory edge first
 740   Node* mem = MergeMemNode::make(map()->memory());
 741   gvn().set_type_bottom(mem);
 742 
 743   SafePointNode *clonemap = (SafePointNode*)map()->clone();
 744   JVMState* jvms = this->jvms();
 745   JVMState* clonejvms = jvms->clone_shallow(C);
 746   clonemap->set_memory(mem);
 747   clonemap->set_jvms(clonejvms);
 748   clonejvms->set_map(clonemap);
 749   record_for_igvn(clonemap);
 750   gvn().set_type_bottom(clonemap);
 751   return clonemap;
 752 }
 753 
 754 //-----------------------------destruct_map_clone------------------------------
 755 //
 756 // Order of destruct is important to increase the likelyhood that memory can be re-used. We need
 757 // to destruct/free/delete in the exact opposite order as clone_map().
 758 void GraphKit::destruct_map_clone(SafePointNode* sfp) {
 759   if (sfp == nullptr) return;
 760 
 761   Node* mem = sfp->memory();
 762   JVMState* jvms = sfp->jvms();
 763 
 764   if (jvms != nullptr) {
 765     delete jvms;
 766   }
 767 
 768   remove_for_igvn(sfp);
 769   gvn().clear_type(sfp);
 770   sfp->destruct(&_gvn);
 771 
 772   if (mem != nullptr) {
 773     gvn().clear_type(mem);
 774     mem->destruct(&_gvn);
 775   }
 776 }
 777 
 778 //-----------------------------set_map_clone-----------------------------------
 779 void GraphKit::set_map_clone(SafePointNode* m) {
 780   _map = m;
 781   _map = clone_map();
 782   _map->set_next_exception(nullptr);
 783   DEBUG_ONLY(verify_map());
 784 }
 785 
 786 
 787 //----------------------------kill_dead_locals---------------------------------
 788 // Detect any locals which are known to be dead, and force them to top.
 789 void GraphKit::kill_dead_locals() {
 790   // Consult the liveness information for the locals.  If any
 791   // of them are unused, then they can be replaced by top().  This
 792   // should help register allocation time and cut down on the size
 793   // of the deoptimization information.
 794 
 795   // This call is made from many of the bytecode handling
 796   // subroutines called from the Big Switch in do_one_bytecode.
 797   // Every bytecode which might include a slow path is responsible
 798   // for killing its dead locals.  The more consistent we
 799   // are about killing deads, the fewer useless phis will be
 800   // constructed for them at various merge points.
 801 
 802   // bci can be -1 (InvocationEntryBci).  We return the entry
 803   // liveness for the method.
 804 
 805   if (method() == nullptr || method()->code_size() == 0) {
 806     // We are building a graph for a call to a native method.
 807     // All locals are live.
 808     return;
 809   }
 810 
 811   ResourceMark rm;
 812 
 813   // Consult the liveness information for the locals.  If any
 814   // of them are unused, then they can be replaced by top().  This
 815   // should help register allocation time and cut down on the size
 816   // of the deoptimization information.
 817   MethodLivenessResult live_locals = method()->liveness_at_bci(bci());
 818 
 819   int len = (int)live_locals.size();
 820   assert(len <= jvms()->loc_size(), "too many live locals");
 821   for (int local = 0; local < len; local++) {
 822     if (!live_locals.at(local)) {
 823       set_local(local, top());
 824     }
 825   }
 826 }
 827 
 828 #ifdef ASSERT
 829 //-------------------------dead_locals_are_killed------------------------------
 830 // Return true if all dead locals are set to top in the map.
 831 // Used to assert "clean" debug info at various points.
 832 bool GraphKit::dead_locals_are_killed() {
 833   if (method() == nullptr || method()->code_size() == 0) {
 834     // No locals need to be dead, so all is as it should be.
 835     return true;
 836   }
 837 
 838   // Make sure somebody called kill_dead_locals upstream.
 839   ResourceMark rm;
 840   for (JVMState* jvms = this->jvms(); jvms != nullptr; jvms = jvms->caller()) {
 841     if (jvms->loc_size() == 0)  continue;  // no locals to consult
 842     SafePointNode* map = jvms->map();
 843     ciMethod* method = jvms->method();
 844     int       bci    = jvms->bci();
 845     if (jvms == this->jvms()) {
 846       bci = this->bci();  // it might not yet be synched
 847     }
 848     MethodLivenessResult live_locals = method->liveness_at_bci(bci);
 849     int len = (int)live_locals.size();
 850     if (!live_locals.is_valid() || len == 0)
 851       // This method is trivial, or is poisoned by a breakpoint.
 852       return true;
 853     assert(len == jvms->loc_size(), "live map consistent with locals map");
 854     for (int local = 0; local < len; local++) {
 855       if (!live_locals.at(local) && map->local(jvms, local) != top()) {
 856         if (PrintMiscellaneous && (Verbose || WizardMode)) {
 857           tty->print_cr("Zombie local %d: ", local);
 858           jvms->dump();
 859         }
 860         return false;
 861       }
 862     }
 863   }
 864   return true;
 865 }
 866 
 867 #endif //ASSERT
 868 
 869 // Helper function for enforcing certain bytecodes to reexecute if deoptimization happens.
 870 static bool should_reexecute_implied_by_bytecode(JVMState *jvms, bool is_anewarray) {
 871   ciMethod* cur_method = jvms->method();
 872   int       cur_bci   = jvms->bci();
 873   if (cur_method != nullptr && cur_bci != InvocationEntryBci) {
 874     Bytecodes::Code code = cur_method->java_code_at_bci(cur_bci);
 875     return Interpreter::bytecode_should_reexecute(code) ||
 876            (is_anewarray && code == Bytecodes::_multianewarray);
 877     // Reexecute _multianewarray bytecode which was replaced with
 878     // sequence of [a]newarray. See Parse::do_multianewarray().
 879     //
 880     // Note: interpreter should not have it set since this optimization
 881     // is limited by dimensions and guarded by flag so in some cases
 882     // multianewarray() runtime calls will be generated and
 883     // the bytecode should not be reexecutes (stack will not be reset).
 884   } else {
 885     return false;
 886   }
 887 }
 888 
 889 // Helper function for adding JVMState and debug information to node
 890 void GraphKit::add_safepoint_edges(SafePointNode* call, bool must_throw) {
 891   // Add the safepoint edges to the call (or other safepoint).
 892 
 893   // Make sure dead locals are set to top.  This
 894   // should help register allocation time and cut down on the size
 895   // of the deoptimization information.
 896   assert(dead_locals_are_killed(), "garbage in debug info before safepoint");
 897 
 898   // Walk the inline list to fill in the correct set of JVMState's
 899   // Also fill in the associated edges for each JVMState.
 900 
 901   // If the bytecode needs to be reexecuted we need to put
 902   // the arguments back on the stack.
 903   const bool should_reexecute = jvms()->should_reexecute();
 904   JVMState* youngest_jvms = should_reexecute ? sync_jvms_for_reexecute() : sync_jvms();
 905 
 906   // NOTE: set_bci (called from sync_jvms) might reset the reexecute bit to
 907   // undefined if the bci is different.  This is normal for Parse but it
 908   // should not happen for LibraryCallKit because only one bci is processed.
 909   assert(!is_LibraryCallKit() || (jvms()->should_reexecute() == should_reexecute),
 910          "in LibraryCallKit the reexecute bit should not change");
 911 
 912   // If we are guaranteed to throw, we can prune everything but the
 913   // input to the current bytecode.
 914   bool can_prune_locals = false;
 915   uint stack_slots_not_pruned = 0;
 916   int inputs = 0, depth = 0;
 917   if (must_throw) {
 918     assert(method() == youngest_jvms->method(), "sanity");
 919     if (compute_stack_effects(inputs, depth)) {
 920       can_prune_locals = true;
 921       stack_slots_not_pruned = inputs;
 922     }
 923   }
 924 
 925   if (env()->should_retain_local_variables()) {
 926     // At any safepoint, this method can get breakpointed, which would
 927     // then require an immediate deoptimization.
 928     can_prune_locals = false;  // do not prune locals
 929     stack_slots_not_pruned = 0;
 930   }
 931 
 932   // do not scribble on the input jvms
 933   JVMState* out_jvms = youngest_jvms->clone_deep(C);
 934   call->set_jvms(out_jvms); // Start jvms list for call node
 935 
 936   // For a known set of bytecodes, the interpreter should reexecute them if
 937   // deoptimization happens. We set the reexecute state for them here
 938   if (out_jvms->is_reexecute_undefined() && //don't change if already specified
 939       should_reexecute_implied_by_bytecode(out_jvms, call->is_AllocateArray())) {
 940 #ifdef ASSERT
 941     int inputs = 0, not_used; // initialized by GraphKit::compute_stack_effects()
 942     assert(method() == youngest_jvms->method(), "sanity");
 943     assert(compute_stack_effects(inputs, not_used), "unknown bytecode: %s", Bytecodes::name(java_bc()));
 944     assert(out_jvms->sp() >= (uint)inputs, "not enough operands for reexecution");
 945 #endif // ASSERT
 946     out_jvms->set_should_reexecute(true); //NOTE: youngest_jvms not changed
 947   }
 948 
 949   // Presize the call:
 950   DEBUG_ONLY(uint non_debug_edges = call->req());
 951   call->add_req_batch(top(), youngest_jvms->debug_depth());
 952   assert(call->req() == non_debug_edges + youngest_jvms->debug_depth(), "");
 953 
 954   // Set up edges so that the call looks like this:
 955   //  Call [state:] ctl io mem fptr retadr
 956   //       [parms:] parm0 ... parmN
 957   //       [root:]  loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN
 958   //    [...mid:]   loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN [...]
 959   //       [young:] loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN
 960   // Note that caller debug info precedes callee debug info.
 961 
 962   // Fill pointer walks backwards from "young:" to "root:" in the diagram above:
 963   uint debug_ptr = call->req();
 964 
 965   // Loop over the map input edges associated with jvms, add them
 966   // to the call node, & reset all offsets to match call node array.
 967   for (JVMState* in_jvms = youngest_jvms; in_jvms != nullptr; ) {
 968     uint debug_end   = debug_ptr;
 969     uint debug_start = debug_ptr - in_jvms->debug_size();
 970     debug_ptr = debug_start;  // back up the ptr
 971 
 972     uint p = debug_start;  // walks forward in [debug_start, debug_end)
 973     uint j, k, l;
 974     SafePointNode* in_map = in_jvms->map();
 975     out_jvms->set_map(call);
 976 
 977     if (can_prune_locals) {
 978       assert(in_jvms->method() == out_jvms->method(), "sanity");
 979       // If the current throw can reach an exception handler in this JVMS,
 980       // then we must keep everything live that can reach that handler.
 981       // As a quick and dirty approximation, we look for any handlers at all.
 982       if (in_jvms->method()->has_exception_handlers()) {
 983         can_prune_locals = false;
 984       }
 985     }
 986 
 987     // Add the Locals
 988     k = in_jvms->locoff();
 989     l = in_jvms->loc_size();
 990     out_jvms->set_locoff(p);
 991     if (!can_prune_locals) {
 992       for (j = 0; j < l; j++)
 993         call->set_req(p++, in_map->in(k+j));
 994     } else {
 995       p += l;  // already set to top above by add_req_batch
 996     }
 997 
 998     // Add the Expression Stack
 999     k = in_jvms->stkoff();
1000     l = in_jvms->sp();
1001     out_jvms->set_stkoff(p);
1002     if (!can_prune_locals) {
1003       for (j = 0; j < l; j++)
1004         call->set_req(p++, in_map->in(k+j));
1005     } else if (can_prune_locals && stack_slots_not_pruned != 0) {
1006       // Divide stack into {S0,...,S1}, where S0 is set to top.
1007       uint s1 = stack_slots_not_pruned;
1008       stack_slots_not_pruned = 0;  // for next iteration
1009       if (s1 > l)  s1 = l;
1010       uint s0 = l - s1;
1011       p += s0;  // skip the tops preinstalled by add_req_batch
1012       for (j = s0; j < l; j++)
1013         call->set_req(p++, in_map->in(k+j));
1014     } else {
1015       p += l;  // already set to top above by add_req_batch
1016     }
1017 
1018     // Add the Monitors
1019     k = in_jvms->monoff();
1020     l = in_jvms->mon_size();
1021     out_jvms->set_monoff(p);
1022     for (j = 0; j < l; j++)
1023       call->set_req(p++, in_map->in(k+j));
1024 
1025     // Copy any scalar object fields.
1026     k = in_jvms->scloff();
1027     l = in_jvms->scl_size();
1028     out_jvms->set_scloff(p);
1029     for (j = 0; j < l; j++)
1030       call->set_req(p++, in_map->in(k+j));
1031 
1032     // Finish the new jvms.
1033     out_jvms->set_endoff(p);
1034 
1035     assert(out_jvms->endoff()     == debug_end,             "fill ptr must match");
1036     assert(out_jvms->depth()      == in_jvms->depth(),      "depth must match");
1037     assert(out_jvms->loc_size()   == in_jvms->loc_size(),   "size must match");
1038     assert(out_jvms->mon_size()   == in_jvms->mon_size(),   "size must match");
1039     assert(out_jvms->scl_size()   == in_jvms->scl_size(),   "size must match");
1040     assert(out_jvms->debug_size() == in_jvms->debug_size(), "size must match");
1041 
1042     // Update the two tail pointers in parallel.
1043     out_jvms = out_jvms->caller();
1044     in_jvms  = in_jvms->caller();
1045   }
1046 
1047   assert(debug_ptr == non_debug_edges, "debug info must fit exactly");
1048 
1049   // Test the correctness of JVMState::debug_xxx accessors:
1050   assert(call->jvms()->debug_start() == non_debug_edges, "");
1051   assert(call->jvms()->debug_end()   == call->req(), "");
1052   assert(call->jvms()->debug_depth() == call->req() - non_debug_edges, "");
1053 }
1054 
1055 bool GraphKit::compute_stack_effects(int& inputs, int& depth) {
1056   Bytecodes::Code code = java_bc();
1057   if (code == Bytecodes::_wide) {
1058     code = method()->java_code_at_bci(bci() + 1);
1059   }
1060 
1061   if (code != Bytecodes::_illegal) {
1062     depth = Bytecodes::depth(code); // checkcast=0, athrow=-1
1063   }
1064 
1065   auto rsize = [&]() {
1066     assert(code != Bytecodes::_illegal, "code is illegal!");
1067     BasicType rtype = Bytecodes::result_type(code); // checkcast=P, athrow=V
1068     return (rtype < T_CONFLICT) ? type2size[rtype] : 0;
1069   };
1070 
1071   switch (code) {
1072   case Bytecodes::_illegal:
1073     return false;
1074 
1075   case Bytecodes::_ldc:
1076   case Bytecodes::_ldc_w:
1077   case Bytecodes::_ldc2_w:
1078     inputs = 0;
1079     break;
1080 
1081   case Bytecodes::_dup:         inputs = 1;  break;
1082   case Bytecodes::_dup_x1:      inputs = 2;  break;
1083   case Bytecodes::_dup_x2:      inputs = 3;  break;
1084   case Bytecodes::_dup2:        inputs = 2;  break;
1085   case Bytecodes::_dup2_x1:     inputs = 3;  break;
1086   case Bytecodes::_dup2_x2:     inputs = 4;  break;
1087   case Bytecodes::_swap:        inputs = 2;  break;
1088   case Bytecodes::_arraylength: inputs = 1;  break;
1089 
1090   case Bytecodes::_getstatic:
1091   case Bytecodes::_putstatic:
1092   case Bytecodes::_getfield:
1093   case Bytecodes::_putfield:
1094     {
1095       bool ignored_will_link;
1096       ciField* field = method()->get_field_at_bci(bci(), ignored_will_link);
1097       int      size  = field->type()->size();
1098       bool is_get = (depth >= 0), is_static = (depth & 1);
1099       inputs = (is_static ? 0 : 1);
1100       if (is_get) {
1101         depth = size - inputs;
1102       } else {
1103         inputs += size;        // putxxx pops the value from the stack
1104         depth = - inputs;
1105       }
1106     }
1107     break;
1108 
1109   case Bytecodes::_invokevirtual:
1110   case Bytecodes::_invokespecial:
1111   case Bytecodes::_invokestatic:
1112   case Bytecodes::_invokedynamic:
1113   case Bytecodes::_invokeinterface:
1114     {
1115       bool ignored_will_link;
1116       ciSignature* declared_signature = nullptr;
1117       ciMethod* ignored_callee = method()->get_method_at_bci(bci(), ignored_will_link, &declared_signature);
1118       assert(declared_signature != nullptr, "cannot be null");
1119       inputs   = declared_signature->arg_size_for_bc(code);
1120       int size = declared_signature->return_type()->size();
1121       depth = size - inputs;
1122     }
1123     break;
1124 
1125   case Bytecodes::_multianewarray:
1126     {
1127       ciBytecodeStream iter(method());
1128       iter.reset_to_bci(bci());
1129       iter.next();
1130       inputs = iter.get_dimensions();
1131       assert(rsize() == 1, "");
1132       depth = 1 - inputs;
1133     }
1134     break;
1135 
1136   case Bytecodes::_ireturn:
1137   case Bytecodes::_lreturn:
1138   case Bytecodes::_freturn:
1139   case Bytecodes::_dreturn:
1140   case Bytecodes::_areturn:
1141     assert(rsize() == -depth, "");
1142     inputs = -depth;
1143     break;
1144 
1145   case Bytecodes::_jsr:
1146   case Bytecodes::_jsr_w:
1147     inputs = 0;
1148     depth  = 1;                  // S.B. depth=1, not zero
1149     break;
1150 
1151   default:
1152     // bytecode produces a typed result
1153     inputs = rsize() - depth;
1154     assert(inputs >= 0, "");
1155     break;
1156   }
1157 
1158 #ifdef ASSERT
1159   // spot check
1160   int outputs = depth + inputs;
1161   assert(outputs >= 0, "sanity");
1162   switch (code) {
1163   case Bytecodes::_checkcast: assert(inputs == 1 && outputs == 1, ""); break;
1164   case Bytecodes::_athrow:    assert(inputs == 1 && outputs == 0, ""); break;
1165   case Bytecodes::_aload_0:   assert(inputs == 0 && outputs == 1, ""); break;
1166   case Bytecodes::_return:    assert(inputs == 0 && outputs == 0, ""); break;
1167   case Bytecodes::_drem:      assert(inputs == 4 && outputs == 2, ""); break;
1168   default:                    break;
1169   }
1170 #endif //ASSERT
1171 
1172   return true;
1173 }
1174 
1175 
1176 
1177 //------------------------------basic_plus_adr---------------------------------
1178 Node* GraphKit::basic_plus_adr(Node* base, Node* ptr, Node* offset) {
1179   // short-circuit a common case
1180   if (offset == MakeConX(0)) {
1181     return ptr;
1182   }
1183 #ifdef ASSERT
1184   // Both 32-bit and 64-bit zeros should have been handled by the previous `if`
1185   // statement, so if we see either 32-bit or 64-bit zeros here, then we have a
1186   // problem.
1187   if (offset->is_Con()) {
1188     const Type* t = offset->bottom_type();
1189     bool is_zero_int = t->isa_int() && t->is_int()->get_con() == 0;
1190     bool is_zero_long = t->isa_long() && t->is_long()->get_con() == 0;
1191     assert(!is_zero_int && !is_zero_long,
1192            "Unexpected zero offset - should have matched MakeConX(0)");
1193   }
1194 #endif
1195   return _gvn.transform( new AddPNode(base, ptr, offset) );
1196 }
1197 
1198 Node* GraphKit::ConvI2L(Node* offset) {
1199   // short-circuit a common case
1200   jint offset_con = find_int_con(offset, Type::OffsetBot);
1201   if (offset_con != Type::OffsetBot) {
1202     return longcon((jlong) offset_con);
1203   }
1204   return _gvn.transform( new ConvI2LNode(offset));
1205 }
1206 
1207 Node* GraphKit::ConvI2UL(Node* offset) {
1208   juint offset_con = (juint) find_int_con(offset, Type::OffsetBot);
1209   if (offset_con != (juint) Type::OffsetBot) {
1210     return longcon((julong) offset_con);
1211   }
1212   Node* conv = _gvn.transform( new ConvI2LNode(offset));
1213   Node* mask = _gvn.transform(ConLNode::make((julong) max_juint));
1214   return _gvn.transform( new AndLNode(conv, mask) );
1215 }
1216 
1217 Node* GraphKit::ConvL2I(Node* offset) {
1218   // short-circuit a common case
1219   jlong offset_con = find_long_con(offset, (jlong)Type::OffsetBot);
1220   if (offset_con != (jlong)Type::OffsetBot) {
1221     return intcon((int) offset_con);
1222   }
1223   return _gvn.transform( new ConvL2INode(offset));
1224 }
1225 
1226 //-------------------------load_object_klass-----------------------------------
1227 Node* GraphKit::load_object_klass(Node* obj) {
1228   // Special-case a fresh allocation to avoid building nodes:
1229   Node* akls = AllocateNode::Ideal_klass(obj, &_gvn);
1230   if (akls != nullptr)  return akls;
1231   Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes());
1232   return _gvn.transform(LoadKlassNode::make(_gvn, immutable_memory(), k_adr, TypeInstPtr::KLASS));
1233 }
1234 
1235 //-------------------------load_array_length-----------------------------------
1236 Node* GraphKit::load_array_length(Node* array) {
1237   // Special-case a fresh allocation to avoid building nodes:
1238   AllocateArrayNode* alloc = AllocateArrayNode::Ideal_array_allocation(array);
1239   Node *alen;
1240   if (alloc == nullptr) {
1241     Node *r_adr = basic_plus_adr(array, arrayOopDesc::length_offset_in_bytes());
1242     alen = _gvn.transform( new LoadRangeNode(nullptr, immutable_memory(), r_adr, TypeInt::POS));
1243   } else {
1244     alen = array_ideal_length(alloc, _gvn.type(array)->is_oopptr(), false);
1245   }
1246   return alen;
1247 }
1248 
1249 Node* GraphKit::array_ideal_length(AllocateArrayNode* alloc,
1250                                    const TypeOopPtr* oop_type,
1251                                    bool replace_length_in_map) {
1252   Node* length = alloc->Ideal_length();
1253   if (replace_length_in_map == false || map()->find_edge(length) >= 0) {
1254     Node* ccast = alloc->make_ideal_length(oop_type, &_gvn);
1255     if (ccast != length) {
1256       // do not transform ccast here, it might convert to top node for
1257       // negative array length and break assumptions in parsing stage.
1258       _gvn.set_type_bottom(ccast);
1259       record_for_igvn(ccast);
1260       if (replace_length_in_map) {
1261         replace_in_map(length, ccast);
1262       }
1263       return ccast;
1264     }
1265   }
1266   return length;
1267 }
1268 
1269 //------------------------------do_null_check----------------------------------
1270 // Helper function to do a null pointer check.  Returned value is
1271 // the incoming address with null casted away.  You are allowed to use the
1272 // not-null value only if you are control dependent on the test.
1273 #ifndef PRODUCT
1274 extern uint explicit_null_checks_inserted,
1275             explicit_null_checks_elided;
1276 #endif
1277 Node* GraphKit::null_check_common(Node* value, BasicType type,
1278                                   // optional arguments for variations:
1279                                   bool assert_null,
1280                                   Node* *null_control,
1281                                   bool speculative) {
1282   assert(!assert_null || null_control == nullptr, "not both at once");
1283   if (stopped())  return top();
1284   NOT_PRODUCT(explicit_null_checks_inserted++);
1285 
1286   // Construct null check
1287   Node *chk = nullptr;
1288   switch(type) {
1289     case T_LONG   : chk = new CmpLNode(value, _gvn.zerocon(T_LONG)); break;
1290     case T_INT    : chk = new CmpINode(value, _gvn.intcon(0)); break;
1291     case T_ARRAY  : // fall through
1292       type = T_OBJECT;  // simplify further tests
1293     case T_OBJECT : {
1294       const Type *t = _gvn.type( value );
1295 
1296       const TypeOopPtr* tp = t->isa_oopptr();
1297       if (tp != nullptr && !tp->is_loaded()
1298           // Only for do_null_check, not any of its siblings:
1299           && !assert_null && null_control == nullptr) {
1300         // Usually, any field access or invocation on an unloaded oop type
1301         // will simply fail to link, since the statically linked class is
1302         // likely also to be unloaded.  However, in -Xcomp mode, sometimes
1303         // the static class is loaded but the sharper oop type is not.
1304         // Rather than checking for this obscure case in lots of places,
1305         // we simply observe that a null check on an unloaded class
1306         // will always be followed by a nonsense operation, so we
1307         // can just issue the uncommon trap here.
1308         // Our access to the unloaded class will only be correct
1309         // after it has been loaded and initialized, which requires
1310         // a trip through the interpreter.
1311         ciKlass* klass = tp->unloaded_klass();
1312 #ifndef PRODUCT
1313         if (WizardMode) { tty->print("Null check of unloaded "); klass->print(); tty->cr(); }
1314 #endif
1315         uncommon_trap(Deoptimization::Reason_unloaded,
1316                       Deoptimization::Action_reinterpret,
1317                       klass, "!loaded");
1318         return top();
1319       }
1320 
1321       if (assert_null) {
1322         // See if the type is contained in NULL_PTR.
1323         // If so, then the value is already null.
1324         if (t->higher_equal(TypePtr::NULL_PTR)) {
1325           NOT_PRODUCT(explicit_null_checks_elided++);
1326           return value;           // Elided null assert quickly!
1327         }
1328       } else {
1329         // See if mixing in the null pointer changes type.
1330         // If so, then the null pointer was not allowed in the original
1331         // type.  In other words, "value" was not-null.
1332         if (t->meet(TypePtr::NULL_PTR) != t->remove_speculative()) {
1333           // same as: if (!TypePtr::NULL_PTR->higher_equal(t)) ...
1334           NOT_PRODUCT(explicit_null_checks_elided++);
1335           return value;           // Elided null check quickly!
1336         }
1337       }
1338       chk = new CmpPNode( value, null() );
1339       break;
1340     }
1341 
1342     default:
1343       fatal("unexpected type: %s", type2name(type));
1344   }
1345   assert(chk != nullptr, "sanity check");
1346   chk = _gvn.transform(chk);
1347 
1348   BoolTest::mask btest = assert_null ? BoolTest::eq : BoolTest::ne;
1349   BoolNode *btst = new BoolNode( chk, btest);
1350   Node   *tst = _gvn.transform( btst );
1351 
1352   //-----------
1353   // if peephole optimizations occurred, a prior test existed.
1354   // If a prior test existed, maybe it dominates as we can avoid this test.
1355   if (tst != btst && type == T_OBJECT) {
1356     // At this point we want to scan up the CFG to see if we can
1357     // find an identical test (and so avoid this test altogether).
1358     Node *cfg = control();
1359     int depth = 0;
1360     while( depth < 16 ) {       // Limit search depth for speed
1361       if( cfg->Opcode() == Op_IfTrue &&
1362           cfg->in(0)->in(1) == tst ) {
1363         // Found prior test.  Use "cast_not_null" to construct an identical
1364         // CastPP (and hence hash to) as already exists for the prior test.
1365         // Return that casted value.
1366         if (assert_null) {
1367           replace_in_map(value, null());
1368           return null();  // do not issue the redundant test
1369         }
1370         Node *oldcontrol = control();
1371         set_control(cfg);
1372         Node *res = cast_not_null(value);
1373         set_control(oldcontrol);
1374         NOT_PRODUCT(explicit_null_checks_elided++);
1375         return res;
1376       }
1377       cfg = IfNode::up_one_dom(cfg, /*linear_only=*/ true);
1378       if (cfg == nullptr)  break;  // Quit at region nodes
1379       depth++;
1380     }
1381   }
1382 
1383   //-----------
1384   // Branch to failure if null
1385   float ok_prob = PROB_MAX;  // a priori estimate:  nulls never happen
1386   Deoptimization::DeoptReason reason;
1387   if (assert_null) {
1388     reason = Deoptimization::reason_null_assert(speculative);
1389   } else if (type == T_OBJECT) {
1390     reason = Deoptimization::reason_null_check(speculative);
1391   } else {
1392     reason = Deoptimization::Reason_div0_check;
1393   }
1394   // %%% Since Reason_unhandled is not recorded on a per-bytecode basis,
1395   // ciMethodData::has_trap_at will return a conservative -1 if any
1396   // must-be-null assertion has failed.  This could cause performance
1397   // problems for a method after its first do_null_assert failure.
1398   // Consider using 'Reason_class_check' instead?
1399 
1400   // To cause an implicit null check, we set the not-null probability
1401   // to the maximum (PROB_MAX).  For an explicit check the probability
1402   // is set to a smaller value.
1403   if (null_control != nullptr || too_many_traps(reason)) {
1404     // probability is less likely
1405     ok_prob =  PROB_LIKELY_MAG(3);
1406   } else if (!assert_null &&
1407              (ImplicitNullCheckThreshold > 0) &&
1408              method() != nullptr &&
1409              (method()->method_data()->trap_count(reason)
1410               >= (uint)ImplicitNullCheckThreshold)) {
1411     ok_prob =  PROB_LIKELY_MAG(3);
1412   }
1413 
1414   if (null_control != nullptr) {
1415     IfNode* iff = create_and_map_if(control(), tst, ok_prob, COUNT_UNKNOWN);
1416     Node* null_true = _gvn.transform( new IfFalseNode(iff));
1417     set_control(      _gvn.transform( new IfTrueNode(iff)));
1418 #ifndef PRODUCT
1419     if (null_true == top()) {
1420       explicit_null_checks_elided++;
1421     }
1422 #endif
1423     (*null_control) = null_true;
1424   } else {
1425     BuildCutout unless(this, tst, ok_prob);
1426     // Check for optimizer eliding test at parse time
1427     if (stopped()) {
1428       // Failure not possible; do not bother making uncommon trap.
1429       NOT_PRODUCT(explicit_null_checks_elided++);
1430     } else if (assert_null) {
1431       uncommon_trap(reason,
1432                     Deoptimization::Action_make_not_entrant,
1433                     nullptr, "assert_null");
1434     } else {
1435       replace_in_map(value, zerocon(type));
1436       builtin_throw(reason);
1437     }
1438   }
1439 
1440   // Must throw exception, fall-thru not possible?
1441   if (stopped()) {
1442     return top();               // No result
1443   }
1444 
1445   if (assert_null) {
1446     // Cast obj to null on this path.
1447     replace_in_map(value, zerocon(type));
1448     return zerocon(type);
1449   }
1450 
1451   // Cast obj to not-null on this path, if there is no null_control.
1452   // (If there is a null_control, a non-null value may come back to haunt us.)
1453   if (type == T_OBJECT) {
1454     Node* cast = cast_not_null(value, false);
1455     if (null_control == nullptr || (*null_control) == top())
1456       replace_in_map(value, cast);
1457     value = cast;
1458   }
1459 
1460   return value;
1461 }
1462 
1463 
1464 //------------------------------cast_not_null----------------------------------
1465 // Cast obj to not-null on this path
1466 Node* GraphKit::cast_not_null(Node* obj, bool do_replace_in_map) {
1467   const Type *t = _gvn.type(obj);
1468   const Type *t_not_null = t->join_speculative(TypePtr::NOTNULL);
1469   // Object is already not-null?
1470   if( t == t_not_null ) return obj;
1471 
1472   Node* cast = new CastPPNode(control(), obj,t_not_null);
1473   cast = _gvn.transform( cast );
1474 
1475   // Scan for instances of 'obj' in the current JVM mapping.
1476   // These instances are known to be not-null after the test.
1477   if (do_replace_in_map)
1478     replace_in_map(obj, cast);
1479 
1480   return cast;                  // Return casted value
1481 }
1482 
1483 // Sometimes in intrinsics, we implicitly know an object is not null
1484 // (there's no actual null check) so we can cast it to not null. In
1485 // the course of optimizations, the input to the cast can become null.
1486 // In that case that data path will die and we need the control path
1487 // to become dead as well to keep the graph consistent. So we have to
1488 // add a check for null for which one branch can't be taken. It uses
1489 // an OpaqueConstantBool node that will cause the check to be removed after loop
1490 // opts so the test goes away and the compiled code doesn't execute a
1491 // useless check.
1492 Node* GraphKit::must_be_not_null(Node* value, bool do_replace_in_map) {
1493   if (!TypePtr::NULL_PTR->higher_equal(_gvn.type(value))) {
1494     return value;
1495   }
1496   Node* chk = _gvn.transform(new CmpPNode(value, null()));
1497   Node* tst = _gvn.transform(new BoolNode(chk, BoolTest::ne));
1498   Node* opaq = _gvn.transform(new OpaqueConstantBoolNode(C, tst, true));
1499   IfNode* iff = new IfNode(control(), opaq, PROB_MAX, COUNT_UNKNOWN);
1500   _gvn.set_type(iff, iff->Value(&_gvn));
1501   if (!tst->is_Con()) {
1502     record_for_igvn(iff);
1503   }
1504   Node *if_f = _gvn.transform(new IfFalseNode(iff));
1505   Node *frame = _gvn.transform(new ParmNode(C->start(), TypeFunc::FramePtr));
1506   halt(if_f, frame, "unexpected null in intrinsic");
1507   Node *if_t = _gvn.transform(new IfTrueNode(iff));
1508   set_control(if_t);
1509   return cast_not_null(value, do_replace_in_map);
1510 }
1511 
1512 
1513 //--------------------------replace_in_map-------------------------------------
1514 void GraphKit::replace_in_map(Node* old, Node* neww) {
1515   if (old == neww) {
1516     return;
1517   }
1518 
1519   map()->replace_edge(old, neww);
1520 
1521   // Note: This operation potentially replaces any edge
1522   // on the map.  This includes locals, stack, and monitors
1523   // of the current (innermost) JVM state.
1524 
1525   // don't let inconsistent types from profiling escape this
1526   // method
1527 
1528   const Type* told = _gvn.type(old);
1529   const Type* tnew = _gvn.type(neww);
1530 
1531   if (!tnew->higher_equal(told)) {
1532     return;
1533   }
1534 
1535   map()->record_replaced_node(old, neww);
1536 }
1537 
1538 
1539 //=============================================================================
1540 //--------------------------------memory---------------------------------------
1541 Node* GraphKit::memory(uint alias_idx) {
1542   MergeMemNode* mem = merged_memory();
1543   Node* p = mem->memory_at(alias_idx);
1544   assert(p != mem->empty_memory(), "empty");
1545   _gvn.set_type(p, Type::MEMORY);  // must be mapped
1546   return p;
1547 }
1548 
1549 //-----------------------------reset_memory------------------------------------
1550 Node* GraphKit::reset_memory() {
1551   Node* mem = map()->memory();
1552   // do not use this node for any more parsing!
1553   DEBUG_ONLY( map()->set_memory((Node*)nullptr) );
1554   return _gvn.transform( mem );
1555 }
1556 
1557 //------------------------------set_all_memory---------------------------------
1558 void GraphKit::set_all_memory(Node* newmem) {
1559   Node* mergemem = MergeMemNode::make(newmem);
1560   gvn().set_type_bottom(mergemem);
1561   map()->set_memory(mergemem);
1562 }
1563 
1564 //------------------------------set_all_memory_call----------------------------
1565 void GraphKit::set_all_memory_call(Node* call, bool separate_io_proj) {
1566   Node* newmem = _gvn.transform( new ProjNode(call, TypeFunc::Memory, separate_io_proj) );
1567   set_all_memory(newmem);
1568 }
1569 
1570 //=============================================================================
1571 //
1572 // parser factory methods for MemNodes
1573 //
1574 // These are layered on top of the factory methods in LoadNode and StoreNode,
1575 // and integrate with the parser's memory state and _gvn engine.
1576 //
1577 
1578 // factory methods in "int adr_idx"
1579 Node* GraphKit::make_load(Node* ctl, Node* adr, const Type* t, BasicType bt,
1580                           MemNode::MemOrd mo,
1581                           LoadNode::ControlDependency control_dependency,
1582                           bool require_atomic_access,
1583                           bool unaligned,
1584                           bool mismatched,
1585                           bool unsafe,
1586                           uint8_t barrier_data) {
1587   int adr_idx = C->get_alias_index(_gvn.type(adr)->isa_ptr());
1588   assert(adr_idx != Compile::AliasIdxTop, "use other make_load factory" );
1589   const TypePtr* adr_type = nullptr; // debug-mode-only argument
1590   DEBUG_ONLY(adr_type = C->get_adr_type(adr_idx));
1591   Node* mem = memory(adr_idx);
1592   Node* ld = LoadNode::make(_gvn, ctl, mem, adr, adr_type, t, bt, mo, control_dependency, require_atomic_access, unaligned, mismatched, unsafe, barrier_data);
1593   ld = _gvn.transform(ld);
1594   if (((bt == T_OBJECT) && C->do_escape_analysis()) || C->eliminate_boxing()) {
1595     // Improve graph before escape analysis and boxing elimination.
1596     record_for_igvn(ld);
1597     if (ld->is_DecodeN()) {
1598       // Also record the actual load (LoadN) in case ld is DecodeN. In some
1599       // rare corner cases, ld->in(1) can be something other than LoadN (e.g.,
1600       // a Phi). Recording such cases is still perfectly sound, but may be
1601       // unnecessary and result in some minor IGVN overhead.
1602       record_for_igvn(ld->in(1));
1603     }
1604   }
1605   return ld;
1606 }
1607 
1608 Node* GraphKit::store_to_memory(Node* ctl, Node* adr, Node *val, BasicType bt,
1609                                 MemNode::MemOrd mo,
1610                                 bool require_atomic_access,
1611                                 bool unaligned,
1612                                 bool mismatched,
1613                                 bool unsafe,
1614                                 int barrier_data) {
1615   int adr_idx = C->get_alias_index(_gvn.type(adr)->isa_ptr());
1616   assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
1617   const TypePtr* adr_type = nullptr;
1618   DEBUG_ONLY(adr_type = C->get_adr_type(adr_idx));
1619   Node *mem = memory(adr_idx);
1620   Node* st = StoreNode::make(_gvn, ctl, mem, adr, adr_type, val, bt, mo, require_atomic_access);
1621   if (unaligned) {
1622     st->as_Store()->set_unaligned_access();
1623   }
1624   if (mismatched) {
1625     st->as_Store()->set_mismatched_access();
1626   }
1627   if (unsafe) {
1628     st->as_Store()->set_unsafe_access();
1629   }
1630   st->as_Store()->set_barrier_data(barrier_data);
1631   st = _gvn.transform(st);
1632   set_memory(st, adr_idx);
1633   // Back-to-back stores can only remove intermediate store with DU info
1634   // so push on worklist for optimizer.
1635   if (mem->req() > MemNode::Address && adr == mem->in(MemNode::Address))
1636     record_for_igvn(st);
1637 
1638   return st;
1639 }
1640 
1641 Node* GraphKit::access_store_at(Node* obj,
1642                                 Node* adr,
1643                                 const TypePtr* adr_type,
1644                                 Node* val,
1645                                 const Type* val_type,
1646                                 BasicType bt,
1647                                 DecoratorSet decorators) {
1648   // Transformation of a value which could be null pointer (CastPP #null)
1649   // could be delayed during Parse (for example, in adjust_map_after_if()).
1650   // Execute transformation here to avoid barrier generation in such case.
1651   if (_gvn.type(val) == TypePtr::NULL_PTR) {
1652     val = _gvn.makecon(TypePtr::NULL_PTR);
1653   }
1654 
1655   if (stopped()) {
1656     return top(); // Dead path ?
1657   }
1658 
1659   assert(val != nullptr, "not dead path");
1660 
1661   C2AccessValuePtr addr(adr, adr_type);
1662   C2AccessValue value(val, val_type);
1663   C2ParseAccess access(this, decorators | C2_WRITE_ACCESS, bt, obj, addr);
1664   if (access.is_raw()) {
1665     return _barrier_set->BarrierSetC2::store_at(access, value);
1666   } else {
1667     return _barrier_set->store_at(access, value);
1668   }
1669 }
1670 
1671 Node* GraphKit::access_load_at(Node* obj,   // containing obj
1672                                Node* adr,   // actual address to store val at
1673                                const TypePtr* adr_type,
1674                                const Type* val_type,
1675                                BasicType bt,
1676                                DecoratorSet decorators) {
1677   if (stopped()) {
1678     return top(); // Dead path ?
1679   }
1680 
1681   C2AccessValuePtr addr(adr, adr_type);
1682   C2ParseAccess access(this, decorators | C2_READ_ACCESS, bt, obj, addr);
1683   if (access.is_raw()) {
1684     return _barrier_set->BarrierSetC2::load_at(access, val_type);
1685   } else {
1686     return _barrier_set->load_at(access, val_type);
1687   }
1688 }
1689 
1690 Node* GraphKit::access_load(Node* adr,   // actual address to load val at
1691                             const Type* val_type,
1692                             BasicType bt,
1693                             DecoratorSet decorators) {
1694   if (stopped()) {
1695     return top(); // Dead path ?
1696   }
1697 
1698   C2AccessValuePtr addr(adr, adr->bottom_type()->is_ptr());
1699   C2ParseAccess access(this, decorators | C2_READ_ACCESS, bt, nullptr, addr);
1700   if (access.is_raw()) {
1701     return _barrier_set->BarrierSetC2::load_at(access, val_type);
1702   } else {
1703     return _barrier_set->load_at(access, val_type);
1704   }
1705 }
1706 
1707 Node* GraphKit::access_atomic_cmpxchg_val_at(Node* obj,
1708                                              Node* adr,
1709                                              const TypePtr* adr_type,
1710                                              int alias_idx,
1711                                              Node* expected_val,
1712                                              Node* new_val,
1713                                              const Type* value_type,
1714                                              BasicType bt,
1715                                              DecoratorSet decorators) {
1716   C2AccessValuePtr addr(adr, adr_type);
1717   C2AtomicParseAccess access(this, decorators | C2_READ_ACCESS | C2_WRITE_ACCESS,
1718                         bt, obj, addr, alias_idx);
1719   if (access.is_raw()) {
1720     return _barrier_set->BarrierSetC2::atomic_cmpxchg_val_at(access, expected_val, new_val, value_type);
1721   } else {
1722     return _barrier_set->atomic_cmpxchg_val_at(access, expected_val, new_val, value_type);
1723   }
1724 }
1725 
1726 Node* GraphKit::access_atomic_cmpxchg_bool_at(Node* obj,
1727                                               Node* adr,
1728                                               const TypePtr* adr_type,
1729                                               int alias_idx,
1730                                               Node* expected_val,
1731                                               Node* new_val,
1732                                               const Type* value_type,
1733                                               BasicType bt,
1734                                               DecoratorSet decorators) {
1735   C2AccessValuePtr addr(adr, adr_type);
1736   C2AtomicParseAccess access(this, decorators | C2_READ_ACCESS | C2_WRITE_ACCESS,
1737                         bt, obj, addr, alias_idx);
1738   if (access.is_raw()) {
1739     return _barrier_set->BarrierSetC2::atomic_cmpxchg_bool_at(access, expected_val, new_val, value_type);
1740   } else {
1741     return _barrier_set->atomic_cmpxchg_bool_at(access, expected_val, new_val, value_type);
1742   }
1743 }
1744 
1745 Node* GraphKit::access_atomic_xchg_at(Node* obj,
1746                                       Node* adr,
1747                                       const TypePtr* adr_type,
1748                                       int alias_idx,
1749                                       Node* new_val,
1750                                       const Type* value_type,
1751                                       BasicType bt,
1752                                       DecoratorSet decorators) {
1753   C2AccessValuePtr addr(adr, adr_type);
1754   C2AtomicParseAccess access(this, decorators | C2_READ_ACCESS | C2_WRITE_ACCESS,
1755                         bt, obj, addr, alias_idx);
1756   if (access.is_raw()) {
1757     return _barrier_set->BarrierSetC2::atomic_xchg_at(access, new_val, value_type);
1758   } else {
1759     return _barrier_set->atomic_xchg_at(access, new_val, value_type);
1760   }
1761 }
1762 
1763 Node* GraphKit::access_atomic_add_at(Node* obj,
1764                                      Node* adr,
1765                                      const TypePtr* adr_type,
1766                                      int alias_idx,
1767                                      Node* new_val,
1768                                      const Type* value_type,
1769                                      BasicType bt,
1770                                      DecoratorSet decorators) {
1771   C2AccessValuePtr addr(adr, adr_type);
1772   C2AtomicParseAccess access(this, decorators | C2_READ_ACCESS | C2_WRITE_ACCESS, bt, obj, addr, alias_idx);
1773   if (access.is_raw()) {
1774     return _barrier_set->BarrierSetC2::atomic_add_at(access, new_val, value_type);
1775   } else {
1776     return _barrier_set->atomic_add_at(access, new_val, value_type);
1777   }
1778 }
1779 
1780 void GraphKit::access_clone(Node* src, Node* dst, Node* size, bool is_array) {
1781   return _barrier_set->clone(this, src, dst, size, is_array);
1782 }
1783 
1784 //-------------------------array_element_address-------------------------
1785 Node* GraphKit::array_element_address(Node* ary, Node* idx, BasicType elembt,
1786                                       const TypeInt* sizetype, Node* ctrl) {
1787   uint shift  = exact_log2(type2aelembytes(elembt));
1788   uint header = arrayOopDesc::base_offset_in_bytes(elembt);
1789 
1790   // short-circuit a common case (saves lots of confusing waste motion)
1791   jint idx_con = find_int_con(idx, -1);
1792   if (idx_con >= 0) {
1793     intptr_t offset = header + ((intptr_t)idx_con << shift);
1794     return basic_plus_adr(ary, offset);
1795   }
1796 
1797   // must be correct type for alignment purposes
1798   Node* base  = basic_plus_adr(ary, header);
1799   idx = Compile::conv_I2X_index(&_gvn, idx, sizetype, ctrl);
1800   Node* scale = _gvn.transform( new LShiftXNode(idx, intcon(shift)) );
1801   return basic_plus_adr(ary, base, scale);
1802 }
1803 
1804 //-------------------------load_array_element-------------------------
1805 Node* GraphKit::load_array_element(Node* ary, Node* idx, const TypeAryPtr* arytype, bool set_ctrl) {
1806   const Type* elemtype = arytype->elem();
1807   BasicType elembt = elemtype->array_element_basic_type();
1808   Node* adr = array_element_address(ary, idx, elembt, arytype->size());
1809   if (elembt == T_NARROWOOP) {
1810     elembt = T_OBJECT; // To satisfy switch in LoadNode::make()
1811   }
1812   Node* ld = access_load_at(ary, adr, arytype, elemtype, elembt,
1813                             IN_HEAP | IS_ARRAY | (set_ctrl ? C2_CONTROL_DEPENDENT_LOAD : 0));
1814   return ld;
1815 }
1816 
1817 //-------------------------set_arguments_for_java_call-------------------------
1818 // Arguments (pre-popped from the stack) are taken from the JVMS.
1819 void GraphKit::set_arguments_for_java_call(CallJavaNode* call) {
1820   // Add the call arguments:
1821   uint nargs = call->method()->arg_size();
1822   for (uint i = 0; i < nargs; i++) {
1823     Node* arg = argument(i);
1824     call->init_req(i + TypeFunc::Parms, arg);
1825   }
1826 }
1827 
1828 //---------------------------set_edges_for_java_call---------------------------
1829 // Connect a newly created call into the current JVMS.
1830 // A return value node (if any) is returned from set_edges_for_java_call.
1831 void GraphKit::set_edges_for_java_call(CallJavaNode* call, bool must_throw, bool separate_io_proj) {
1832 
1833   // Add the predefined inputs:
1834   call->init_req( TypeFunc::Control, control() );
1835   call->init_req( TypeFunc::I_O    , i_o() );
1836   call->init_req( TypeFunc::Memory , reset_memory() );
1837   call->init_req( TypeFunc::FramePtr, frameptr() );
1838   call->init_req( TypeFunc::ReturnAdr, top() );
1839 
1840   add_safepoint_edges(call, must_throw);
1841 
1842   Node* xcall = _gvn.transform(call);
1843 
1844   if (xcall == top()) {
1845     set_control(top());
1846     return;
1847   }
1848   assert(xcall == call, "call identity is stable");
1849 
1850   // Re-use the current map to produce the result.
1851 
1852   set_control(_gvn.transform(new ProjNode(call, TypeFunc::Control)));
1853   set_i_o(    _gvn.transform(new ProjNode(call, TypeFunc::I_O    , separate_io_proj)));
1854   set_all_memory_call(xcall, separate_io_proj);
1855 
1856   //return xcall;   // no need, caller already has it
1857 }
1858 
1859 Node* GraphKit::set_results_for_java_call(CallJavaNode* call, bool separate_io_proj, bool deoptimize) {
1860   if (stopped())  return top();  // maybe the call folded up?
1861 
1862   // Capture the return value, if any.
1863   Node* ret;
1864   if (call->method() == nullptr ||
1865       call->method()->return_type()->basic_type() == T_VOID)
1866         ret = top();
1867   else  ret = _gvn.transform(new ProjNode(call, TypeFunc::Parms));
1868 
1869   // Note:  Since any out-of-line call can produce an exception,
1870   // we always insert an I_O projection from the call into the result.
1871 
1872   make_slow_call_ex(call, env()->Throwable_klass(), separate_io_proj, deoptimize);
1873 
1874   if (separate_io_proj) {
1875     // The caller requested separate projections be used by the fall
1876     // through and exceptional paths, so replace the projections for
1877     // the fall through path.
1878     set_i_o(_gvn.transform( new ProjNode(call, TypeFunc::I_O) ));
1879     set_all_memory(_gvn.transform( new ProjNode(call, TypeFunc::Memory) ));
1880   }
1881   return ret;
1882 }
1883 
1884 //--------------------set_predefined_input_for_runtime_call--------------------
1885 // Reading and setting the memory state is way conservative here.
1886 // The real problem is that I am not doing real Type analysis on memory,
1887 // so I cannot distinguish card mark stores from other stores.  Across a GC
1888 // point the Store Barrier and the card mark memory has to agree.  I cannot
1889 // have a card mark store and its barrier split across the GC point from
1890 // either above or below.  Here I get that to happen by reading ALL of memory.
1891 // A better answer would be to separate out card marks from other memory.
1892 // For now, return the input memory state, so that it can be reused
1893 // after the call, if this call has restricted memory effects.
1894 Node* GraphKit::set_predefined_input_for_runtime_call(SafePointNode* call, Node* narrow_mem) {
1895   // Set fixed predefined input arguments
1896   call->init_req(TypeFunc::Control, control());
1897   call->init_req(TypeFunc::I_O, top()); // does no i/o
1898   call->init_req(TypeFunc::ReturnAdr, top());
1899   if (call->is_CallLeafPure()) {
1900     call->init_req(TypeFunc::Memory, top());
1901     call->init_req(TypeFunc::FramePtr, top());
1902     return nullptr;
1903   } else {
1904     Node* memory = reset_memory();
1905     Node* m = narrow_mem == nullptr ? memory : narrow_mem;
1906     call->init_req(TypeFunc::Memory, m); // may gc ptrs
1907     call->init_req(TypeFunc::FramePtr, frameptr());
1908     return memory;
1909   }
1910 }
1911 
1912 //-------------------set_predefined_output_for_runtime_call--------------------
1913 // Set control and memory (not i_o) from the call.
1914 // If keep_mem is not null, use it for the output state,
1915 // except for the RawPtr output of the call, if hook_mem is TypeRawPtr::BOTTOM.
1916 // If hook_mem is null, this call produces no memory effects at all.
1917 // If hook_mem is a Java-visible memory slice (such as arraycopy operands),
1918 // then only that memory slice is taken from the call.
1919 // In the last case, we must put an appropriate memory barrier before
1920 // the call, so as to create the correct anti-dependencies on loads
1921 // preceding the call.
1922 void GraphKit::set_predefined_output_for_runtime_call(Node* call,
1923                                                       Node* keep_mem,
1924                                                       const TypePtr* hook_mem) {
1925   // no i/o
1926   set_control(_gvn.transform( new ProjNode(call,TypeFunc::Control) ));
1927   if (call->is_CallLeafPure()) {
1928     // Pure function have only control (for now) and data output, in particular
1929     // they don't touch the memory, so we don't want a memory proj that is set after.
1930     return;
1931   }
1932   if (keep_mem) {
1933     // First clone the existing memory state
1934     set_all_memory(keep_mem);
1935     if (hook_mem != nullptr) {
1936       // Make memory for the call
1937       Node* mem = _gvn.transform( new ProjNode(call, TypeFunc::Memory) );
1938       // Set the RawPtr memory state only.  This covers all the heap top/GC stuff
1939       // We also use hook_mem to extract specific effects from arraycopy stubs.
1940       set_memory(mem, hook_mem);
1941     }
1942     // ...else the call has NO memory effects.
1943 
1944     // Make sure the call advertises its memory effects precisely.
1945     // This lets us build accurate anti-dependences in gcm.cpp.
1946     assert(C->alias_type(call->adr_type()) == C->alias_type(hook_mem),
1947            "call node must be constructed correctly");
1948   } else {
1949     assert(hook_mem == nullptr, "");
1950     // This is not a "slow path" call; all memory comes from the call.
1951     set_all_memory_call(call);
1952   }
1953 }
1954 
1955 // Keep track of MergeMems feeding into other MergeMems
1956 static void add_mergemem_users_to_worklist(Unique_Node_List& wl, Node* mem) {
1957   if (!mem->is_MergeMem()) {
1958     return;
1959   }
1960   for (SimpleDUIterator i(mem); i.has_next(); i.next()) {
1961     Node* use = i.get();
1962     if (use->is_MergeMem()) {
1963       wl.push(use);
1964     }
1965   }
1966 }
1967 
1968 // Replace the call with the current state of the kit.
1969 void GraphKit::replace_call(CallNode* call, Node* result, bool do_replaced_nodes, bool do_asserts) {
1970   JVMState* ejvms = nullptr;
1971   if (has_exceptions()) {
1972     ejvms = transfer_exceptions_into_jvms();
1973   }
1974 
1975   ReplacedNodes replaced_nodes = map()->replaced_nodes();
1976   ReplacedNodes replaced_nodes_exception;
1977   Node* ex_ctl = top();
1978 
1979   SafePointNode* final_state = stop();
1980 
1981   // Find all the needed outputs of this call
1982   CallProjections callprojs;
1983   call->extract_projections(&callprojs, true, do_asserts);
1984 
1985   Unique_Node_List wl;
1986   Node* init_mem = call->in(TypeFunc::Memory);
1987   Node* final_mem = final_state->in(TypeFunc::Memory);
1988   Node* final_ctl = final_state->in(TypeFunc::Control);
1989   Node* final_io = final_state->in(TypeFunc::I_O);
1990 
1991   // Replace all the old call edges with the edges from the inlining result
1992   if (callprojs.fallthrough_catchproj != nullptr) {
1993     C->gvn_replace_by(callprojs.fallthrough_catchproj, final_ctl);
1994   }
1995   if (callprojs.fallthrough_memproj != nullptr) {
1996     if (final_mem->is_MergeMem()) {
1997       // Parser's exits MergeMem was not transformed but may be optimized
1998       final_mem = _gvn.transform(final_mem);
1999     }
2000     C->gvn_replace_by(callprojs.fallthrough_memproj,   final_mem);
2001     add_mergemem_users_to_worklist(wl, final_mem);
2002   }
2003   if (callprojs.fallthrough_ioproj != nullptr) {
2004     C->gvn_replace_by(callprojs.fallthrough_ioproj,    final_io);
2005   }
2006 
2007   // Replace the result with the new result if it exists and is used
2008   if (callprojs.resproj != nullptr && result != nullptr) {
2009     C->gvn_replace_by(callprojs.resproj, result);
2010   }
2011 
2012   if (ejvms == nullptr) {
2013     // No exception edges to simply kill off those paths
2014     if (callprojs.catchall_catchproj != nullptr) {
2015       C->gvn_replace_by(callprojs.catchall_catchproj, C->top());
2016     }
2017     if (callprojs.catchall_memproj != nullptr) {
2018       C->gvn_replace_by(callprojs.catchall_memproj,   C->top());
2019     }
2020     if (callprojs.catchall_ioproj != nullptr) {
2021       C->gvn_replace_by(callprojs.catchall_ioproj,    C->top());
2022     }
2023     // Replace the old exception object with top
2024     if (callprojs.exobj != nullptr) {
2025       C->gvn_replace_by(callprojs.exobj, C->top());
2026     }
2027   } else {
2028     GraphKit ekit(ejvms);
2029 
2030     // Load my combined exception state into the kit, with all phis transformed:
2031     SafePointNode* ex_map = ekit.combine_and_pop_all_exception_states();
2032     replaced_nodes_exception = ex_map->replaced_nodes();
2033 
2034     Node* ex_oop = ekit.use_exception_state(ex_map);
2035 
2036     if (callprojs.catchall_catchproj != nullptr) {
2037       C->gvn_replace_by(callprojs.catchall_catchproj, ekit.control());
2038       ex_ctl = ekit.control();
2039     }
2040     if (callprojs.catchall_memproj != nullptr) {
2041       Node* ex_mem = ekit.reset_memory();
2042       C->gvn_replace_by(callprojs.catchall_memproj,   ex_mem);
2043       add_mergemem_users_to_worklist(wl, ex_mem);
2044     }
2045     if (callprojs.catchall_ioproj != nullptr) {
2046       C->gvn_replace_by(callprojs.catchall_ioproj,    ekit.i_o());
2047     }
2048 
2049     // Replace the old exception object with the newly created one
2050     if (callprojs.exobj != nullptr) {
2051       C->gvn_replace_by(callprojs.exobj, ex_oop);
2052     }
2053   }
2054 
2055   // Disconnect the call from the graph
2056   call->disconnect_inputs(C);
2057   C->gvn_replace_by(call, C->top());
2058 
2059   // Clean up any MergeMems that feed other MergeMems since the
2060   // optimizer doesn't like that.
2061   while (wl.size() > 0) {
2062     _gvn.transform(wl.pop());
2063   }
2064 
2065   if (callprojs.fallthrough_catchproj != nullptr && !final_ctl->is_top() && do_replaced_nodes) {
2066     replaced_nodes.apply(C, final_ctl);
2067   }
2068   if (!ex_ctl->is_top() && do_replaced_nodes) {
2069     replaced_nodes_exception.apply(C, ex_ctl);
2070   }
2071 }
2072 
2073 
2074 //------------------------------increment_counter------------------------------
2075 // for statistics: increment a VM counter by 1
2076 
2077 void GraphKit::increment_counter(address counter_addr) {
2078   Node* adr1 = makecon(TypeRawPtr::make(counter_addr));
2079   increment_counter(adr1);
2080 }
2081 
2082 void GraphKit::increment_counter(Node* counter_addr) {
2083   Node* ctrl = control();
2084   Node* cnt  = make_load(ctrl, counter_addr, TypeLong::LONG, T_LONG, MemNode::unordered);
2085   Node* incr = _gvn.transform(new AddLNode(cnt, _gvn.longcon(1)));
2086   store_to_memory(ctrl, counter_addr, incr, T_LONG, MemNode::unordered);
2087 }
2088 
2089 void GraphKit::halt(Node* ctrl, Node* frameptr, const char* reason, bool generate_code_in_product) {
2090   Node* halt = new HaltNode(ctrl, frameptr, reason
2091                             PRODUCT_ONLY(COMMA generate_code_in_product));
2092   halt = _gvn.transform(halt);
2093   root()->add_req(halt);
2094 }
2095 
2096 //------------------------------uncommon_trap----------------------------------
2097 // Bail out to the interpreter in mid-method.  Implemented by calling the
2098 // uncommon_trap blob.  This helper function inserts a runtime call with the
2099 // right debug info.
2100 Node* GraphKit::uncommon_trap(int trap_request,
2101                              ciKlass* klass, const char* comment,
2102                              bool must_throw,
2103                              bool keep_exact_action) {
2104   if (failing_internal()) {
2105     stop();
2106   }
2107   if (stopped())  return nullptr; // trap reachable?
2108 
2109   // Note:  If ProfileTraps is true, and if a deopt. actually
2110   // occurs here, the runtime will make sure an MDO exists.  There is
2111   // no need to call method()->ensure_method_data() at this point.
2112 
2113   // Set the stack pointer to the right value for reexecution:
2114   set_sp(reexecute_sp());
2115 
2116 #ifdef ASSERT
2117   if (!must_throw) {
2118     // Make sure the stack has at least enough depth to execute
2119     // the current bytecode.
2120     int inputs, ignored_depth;
2121     if (compute_stack_effects(inputs, ignored_depth)) {
2122       assert(sp() >= inputs, "must have enough JVMS stack to execute %s: sp=%d, inputs=%d",
2123              Bytecodes::name(java_bc()), sp(), inputs);
2124     }
2125   }
2126 #endif
2127 
2128   Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(trap_request);
2129   Deoptimization::DeoptAction action = Deoptimization::trap_request_action(trap_request);
2130 
2131   switch (action) {
2132   case Deoptimization::Action_maybe_recompile:
2133   case Deoptimization::Action_reinterpret:
2134     // Temporary fix for 6529811 to allow virtual calls to be sure they
2135     // get the chance to go from mono->bi->mega
2136     if (!keep_exact_action &&
2137         Deoptimization::trap_request_index(trap_request) < 0 &&
2138         too_many_recompiles(reason)) {
2139       // This BCI is causing too many recompilations.
2140       if (C->log() != nullptr) {
2141         C->log()->elem("observe that='trap_action_change' reason='%s' from='%s' to='none'",
2142                 Deoptimization::trap_reason_name(reason),
2143                 Deoptimization::trap_action_name(action));
2144       }
2145       action = Deoptimization::Action_none;
2146       trap_request = Deoptimization::make_trap_request(reason, action);
2147     } else {
2148       C->set_trap_can_recompile(true);
2149     }
2150     break;
2151   case Deoptimization::Action_make_not_entrant:
2152     C->set_trap_can_recompile(true);
2153     break;
2154   case Deoptimization::Action_none:
2155   case Deoptimization::Action_make_not_compilable:
2156     break;
2157   default:
2158 #ifdef ASSERT
2159     fatal("unknown action %d: %s", action, Deoptimization::trap_action_name(action));
2160 #endif
2161     break;
2162   }
2163 
2164   if (TraceOptoParse) {
2165     char buf[100];
2166     tty->print_cr("Uncommon trap %s at bci:%d",
2167                   Deoptimization::format_trap_request(buf, sizeof(buf),
2168                                                       trap_request), bci());
2169   }
2170 
2171   CompileLog* log = C->log();
2172   if (log != nullptr) {
2173     int kid = (klass == nullptr)? -1: log->identify(klass);
2174     log->begin_elem("uncommon_trap bci='%d'", bci());
2175     char buf[100];
2176     log->print(" %s", Deoptimization::format_trap_request(buf, sizeof(buf),
2177                                                           trap_request));
2178     if (kid >= 0)         log->print(" klass='%d'", kid);
2179     if (comment != nullptr)  log->print(" comment='%s'", comment);
2180     log->end_elem();
2181   }
2182 
2183   // Make sure any guarding test views this path as very unlikely
2184   Node *i0 = control()->in(0);
2185   if (i0 != nullptr && i0->is_If()) {        // Found a guarding if test?
2186     IfNode *iff = i0->as_If();
2187     float f = iff->_prob;   // Get prob
2188     if (control()->Opcode() == Op_IfTrue) {
2189       if (f > PROB_UNLIKELY_MAG(4))
2190         iff->_prob = PROB_MIN;
2191     } else {
2192       if (f < PROB_LIKELY_MAG(4))
2193         iff->_prob = PROB_MAX;
2194     }
2195   }
2196 
2197   // Clear out dead values from the debug info.
2198   kill_dead_locals();
2199 
2200   // Now insert the uncommon trap subroutine call
2201   address call_addr = OptoRuntime::uncommon_trap_blob()->entry_point();
2202   const TypePtr* no_memory_effects = nullptr;
2203   // Pass the index of the class to be loaded
2204   Node* call = make_runtime_call(RC_NO_LEAF | RC_UNCOMMON |
2205                                  (must_throw ? RC_MUST_THROW : 0),
2206                                  OptoRuntime::uncommon_trap_Type(),
2207                                  call_addr, "uncommon_trap", no_memory_effects,
2208                                  intcon(trap_request));
2209   assert(call->as_CallStaticJava()->uncommon_trap_request() == trap_request,
2210          "must extract request correctly from the graph");
2211   assert(trap_request != 0, "zero value reserved by uncommon_trap_request");
2212 
2213   call->set_req(TypeFunc::ReturnAdr, returnadr());
2214   // The debug info is the only real input to this call.
2215 
2216   // Halt-and-catch fire here.  The above call should never return!
2217   // We only emit code for the HaltNode in debug, which is enough for
2218   // verifying correctness. In product, we don't want to emit it so
2219   // that we can save on code space. HaltNode often get folded because
2220   // the compiler can prove that the unreachable path is dead. But we
2221   // cannot generally expect that for uncommon traps, which are often
2222   // reachable and occasionally taken.
2223   halt(control(), frameptr(),
2224        "uncommon trap returned which should never happen",
2225        false /* don't emit code in product */);
2226   stop_and_kill_map();
2227   return call;
2228 }
2229 
2230 
2231 //--------------------------just_allocated_object------------------------------
2232 // Report the object that was just allocated.
2233 // It must be the case that there are no intervening safepoints.
2234 // We use this to determine if an object is so "fresh" that
2235 // it does not require card marks.
2236 Node* GraphKit::just_allocated_object(Node* current_control) {
2237   Node* ctrl = current_control;
2238   // Object::<init> is invoked after allocation, most of invoke nodes
2239   // will be reduced, but a region node is kept in parse time, we check
2240   // the pattern and skip the region node if it degraded to a copy.
2241   if (ctrl != nullptr && ctrl->is_Region() && ctrl->req() == 2 &&
2242       ctrl->as_Region()->is_copy()) {
2243     ctrl = ctrl->as_Region()->is_copy();
2244   }
2245   if (C->recent_alloc_ctl() == ctrl) {
2246    return C->recent_alloc_obj();
2247   }
2248   return nullptr;
2249 }
2250 
2251 
2252 /**
2253  * Record profiling data exact_kls for Node n with the type system so
2254  * that it can propagate it (speculation)
2255  *
2256  * @param n          node that the type applies to
2257  * @param exact_kls  type from profiling
2258  * @param maybe_null did profiling see null?
2259  *
2260  * @return           node with improved type
2261  */
2262 Node* GraphKit::record_profile_for_speculation(Node* n, ciKlass* exact_kls, ProfilePtrKind ptr_kind) {
2263   const Type* current_type = _gvn.type(n);
2264   assert(UseTypeSpeculation, "type speculation must be on");
2265 
2266   const TypePtr* speculative = current_type->speculative();
2267 
2268   // Should the klass from the profile be recorded in the speculative type?
2269   if (current_type->would_improve_type(exact_kls, jvms()->depth())) {
2270     const TypeKlassPtr* tklass = TypeKlassPtr::make(exact_kls, Type::trust_interfaces);
2271     const TypeOopPtr* xtype = tklass->as_instance_type();
2272     assert(xtype->klass_is_exact(), "Should be exact");
2273     // Any reason to believe n is not null (from this profiling or a previous one)?
2274     assert(ptr_kind != ProfileAlwaysNull, "impossible here");
2275     const TypePtr* ptr = (ptr_kind == ProfileMaybeNull && current_type->speculative_maybe_null()) ? TypePtr::BOTTOM : TypePtr::NOTNULL;
2276     // record the new speculative type's depth
2277     speculative = xtype->cast_to_ptr_type(ptr->ptr())->is_ptr();
2278     speculative = speculative->with_inline_depth(jvms()->depth());
2279   } else if (current_type->would_improve_ptr(ptr_kind)) {
2280     // Profiling report that null was never seen so we can change the
2281     // speculative type to non null ptr.
2282     if (ptr_kind == ProfileAlwaysNull) {
2283       speculative = TypePtr::NULL_PTR;
2284     } else {
2285       assert(ptr_kind == ProfileNeverNull, "nothing else is an improvement");
2286       const TypePtr* ptr = TypePtr::NOTNULL;
2287       if (speculative != nullptr) {
2288         speculative = speculative->cast_to_ptr_type(ptr->ptr())->is_ptr();
2289       } else {
2290         speculative = ptr;
2291       }
2292     }
2293   }
2294 
2295   if (speculative != current_type->speculative()) {
2296     // Build a type with a speculative type (what we think we know
2297     // about the type but will need a guard when we use it)
2298     const TypeOopPtr* spec_type = TypeOopPtr::make(TypePtr::BotPTR, Type::OffsetBot, TypeOopPtr::InstanceBot, speculative);
2299     // We're changing the type, we need a new CheckCast node to carry
2300     // the new type. The new type depends on the control: what
2301     // profiling tells us is only valid from here as far as we can
2302     // tell.
2303     Node* cast = new CheckCastPPNode(control(), n, current_type->remove_speculative()->join_speculative(spec_type));
2304     cast = _gvn.transform(cast);
2305     replace_in_map(n, cast);
2306     n = cast;
2307   }
2308 
2309   return n;
2310 }
2311 
2312 /**
2313  * Record profiling data from receiver profiling at an invoke with the
2314  * type system so that it can propagate it (speculation)
2315  *
2316  * @param n  receiver node
2317  *
2318  * @return   node with improved type
2319  */
2320 Node* GraphKit::record_profiled_receiver_for_speculation(Node* n) {
2321   if (!UseTypeSpeculation) {
2322     return n;
2323   }
2324   ciKlass* exact_kls = profile_has_unique_klass();
2325   ProfilePtrKind ptr_kind = ProfileMaybeNull;
2326   if ((java_bc() == Bytecodes::_checkcast ||
2327        java_bc() == Bytecodes::_instanceof ||
2328        java_bc() == Bytecodes::_aastore) &&
2329       method()->method_data()->is_mature()) {
2330     ciProfileData* data = method()->method_data()->bci_to_data(bci());
2331     if (data != nullptr) {
2332       if (!data->as_BitData()->null_seen()) {
2333         ptr_kind = ProfileNeverNull;
2334       } else {
2335         if (TypeProfileCasts) {
2336           assert(data->is_ReceiverTypeData(), "bad profile data type");
2337           ciReceiverTypeData* call = (ciReceiverTypeData*)data->as_ReceiverTypeData();
2338           uint i = 0;
2339           for (; i < call->row_limit(); i++) {
2340             ciKlass* receiver = call->receiver(i);
2341             if (receiver != nullptr) {
2342               break;
2343             }
2344           }
2345           ptr_kind = (i == call->row_limit()) ? ProfileAlwaysNull : ProfileMaybeNull;
2346         }
2347       }
2348     }
2349   }
2350   return record_profile_for_speculation(n, exact_kls, ptr_kind);
2351 }
2352 
2353 /**
2354  * Record profiling data from argument profiling at an invoke with the
2355  * type system so that it can propagate it (speculation)
2356  *
2357  * @param dest_method  target method for the call
2358  * @param bc           what invoke bytecode is this?
2359  */
2360 void GraphKit::record_profiled_arguments_for_speculation(ciMethod* dest_method, Bytecodes::Code bc) {
2361   if (!UseTypeSpeculation) {
2362     return;
2363   }
2364   const TypeFunc* tf    = TypeFunc::make(dest_method);
2365   int             nargs = tf->domain()->cnt() - TypeFunc::Parms;
2366   int skip = Bytecodes::has_receiver(bc) ? 1 : 0;
2367   for (int j = skip, i = 0; j < nargs && i < TypeProfileArgsLimit; j++) {
2368     const Type *targ = tf->domain()->field_at(j + TypeFunc::Parms);
2369     if (is_reference_type(targ->basic_type())) {
2370       ProfilePtrKind ptr_kind = ProfileMaybeNull;
2371       ciKlass* better_type = nullptr;
2372       if (method()->argument_profiled_type(bci(), i, better_type, ptr_kind)) {
2373         record_profile_for_speculation(argument(j), better_type, ptr_kind);
2374       }
2375       i++;
2376     }
2377   }
2378 }
2379 
2380 /**
2381  * Record profiling data from parameter profiling at an invoke with
2382  * the type system so that it can propagate it (speculation)
2383  */
2384 void GraphKit::record_profiled_parameters_for_speculation() {
2385   if (!UseTypeSpeculation) {
2386     return;
2387   }
2388   for (int i = 0, j = 0; i < method()->arg_size() ; i++) {
2389     if (_gvn.type(local(i))->isa_oopptr()) {
2390       ProfilePtrKind ptr_kind = ProfileMaybeNull;
2391       ciKlass* better_type = nullptr;
2392       if (method()->parameter_profiled_type(j, better_type, ptr_kind)) {
2393         record_profile_for_speculation(local(i), better_type, ptr_kind);
2394       }
2395       j++;
2396     }
2397   }
2398 }
2399 
2400 /**
2401  * Record profiling data from return value profiling at an invoke with
2402  * the type system so that it can propagate it (speculation)
2403  */
2404 void GraphKit::record_profiled_return_for_speculation() {
2405   if (!UseTypeSpeculation) {
2406     return;
2407   }
2408   ProfilePtrKind ptr_kind = ProfileMaybeNull;
2409   ciKlass* better_type = nullptr;
2410   if (method()->return_profiled_type(bci(), better_type, ptr_kind)) {
2411     // If profiling reports a single type for the return value,
2412     // feed it to the type system so it can propagate it as a
2413     // speculative type
2414     record_profile_for_speculation(stack(sp()-1), better_type, ptr_kind);
2415   }
2416 }
2417 
2418 
2419 //=============================================================================
2420 // Generate a fast path/slow path idiom.  Graph looks like:
2421 // [foo] indicates that 'foo' is a parameter
2422 //
2423 //              [in]     null
2424 //                 \    /
2425 //                  CmpP
2426 //                  Bool ne
2427 //                   If
2428 //                  /  \
2429 //              True    False-<2>
2430 //              / |
2431 //             /  cast_not_null
2432 //           Load  |    |   ^
2433 //        [fast_test]   |   |
2434 // gvn to   opt_test    |   |
2435 //          /    \      |  <1>
2436 //      True     False  |
2437 //        |         \\  |
2438 //   [slow_call]     \[fast_result]
2439 //    Ctl   Val       \      \
2440 //     |               \      \
2441 //    Catch       <1>   \      \
2442 //   /    \        ^     \      \
2443 //  Ex    No_Ex    |      \      \
2444 //  |       \   \  |       \ <2>  \
2445 //  ...      \  [slow_res] |  |    \   [null_result]
2446 //            \         \--+--+---  |  |
2447 //             \           | /    \ | /
2448 //              --------Region     Phi
2449 //
2450 //=============================================================================
2451 // Code is structured as a series of driver functions all called 'do_XXX' that
2452 // call a set of helper functions.  Helper functions first, then drivers.
2453 
2454 //------------------------------null_check_oop---------------------------------
2455 // Null check oop.  Set null-path control into Region in slot 3.
2456 // Make a cast-not-nullness use the other not-null control.  Return cast.
2457 Node* GraphKit::null_check_oop(Node* value, Node* *null_control,
2458                                bool never_see_null,
2459                                bool safe_for_replace,
2460                                bool speculative) {
2461   // Initial null check taken path
2462   (*null_control) = top();
2463   Node* cast = null_check_common(value, T_OBJECT, false, null_control, speculative);
2464 
2465   // Generate uncommon_trap:
2466   if (never_see_null && (*null_control) != top()) {
2467     // If we see an unexpected null at a check-cast we record it and force a
2468     // recompile; the offending check-cast will be compiled to handle nulls.
2469     // If we see more than one offending BCI, then all checkcasts in the
2470     // method will be compiled to handle nulls.
2471     PreserveJVMState pjvms(this);
2472     set_control(*null_control);
2473     replace_in_map(value, null());
2474     Deoptimization::DeoptReason reason = Deoptimization::reason_null_check(speculative);
2475     uncommon_trap(reason,
2476                   Deoptimization::Action_make_not_entrant);
2477     (*null_control) = top();    // null path is dead
2478   }
2479   if ((*null_control) == top() && safe_for_replace) {
2480     replace_in_map(value, cast);
2481   }
2482 
2483   // Cast away null-ness on the result
2484   return cast;
2485 }
2486 
2487 //------------------------------opt_iff----------------------------------------
2488 // Optimize the fast-check IfNode.  Set the fast-path region slot 2.
2489 // Return slow-path control.
2490 Node* GraphKit::opt_iff(Node* region, Node* iff) {
2491   IfNode *opt_iff = _gvn.transform(iff)->as_If();
2492 
2493   // Fast path taken; set region slot 2
2494   Node *fast_taken = _gvn.transform( new IfFalseNode(opt_iff) );
2495   region->init_req(2,fast_taken); // Capture fast-control
2496 
2497   // Fast path not-taken, i.e. slow path
2498   Node *slow_taken = _gvn.transform( new IfTrueNode(opt_iff) );
2499   return slow_taken;
2500 }
2501 
2502 //-----------------------------make_runtime_call-------------------------------
2503 Node* GraphKit::make_runtime_call(int flags,
2504                                   const TypeFunc* call_type, address call_addr,
2505                                   const char* call_name,
2506                                   const TypePtr* adr_type,
2507                                   // The following parms are all optional.
2508                                   // The first null ends the list.
2509                                   Node* parm0, Node* parm1,
2510                                   Node* parm2, Node* parm3,
2511                                   Node* parm4, Node* parm5,
2512                                   Node* parm6, Node* parm7) {
2513   assert(call_addr != nullptr, "must not call null targets");
2514 
2515   // Slow-path call
2516   bool is_leaf = !(flags & RC_NO_LEAF);
2517   bool has_io  = (!is_leaf && !(flags & RC_NO_IO));
2518   if (call_name == nullptr) {
2519     assert(!is_leaf, "must supply name for leaf");
2520     call_name = OptoRuntime::stub_name(call_addr);
2521   }
2522   CallNode* call;
2523   if (!is_leaf) {
2524     call = new CallStaticJavaNode(call_type, call_addr, call_name, adr_type);
2525   } else if (flags & RC_NO_FP) {
2526     call = new CallLeafNoFPNode(call_type, call_addr, call_name, adr_type);
2527   } else  if (flags & RC_VECTOR){
2528     uint num_bits = call_type->range()->field_at(TypeFunc::Parms)->is_vect()->length_in_bytes() * BitsPerByte;
2529     call = new CallLeafVectorNode(call_type, call_addr, call_name, adr_type, num_bits);
2530   } else if (flags & RC_PURE) {
2531     assert(adr_type == nullptr, "pure call does not touch memory");
2532     call = new CallLeafPureNode(call_type, call_addr, call_name);
2533   } else {
2534     call = new CallLeafNode(call_type, call_addr, call_name, adr_type);
2535   }
2536 
2537   // The following is similar to set_edges_for_java_call,
2538   // except that the memory effects of the call are restricted to AliasIdxRaw.
2539 
2540   // Slow path call has no side-effects, uses few values
2541   bool wide_in  = !(flags & RC_NARROW_MEM);
2542   bool wide_out = (C->get_alias_index(adr_type) == Compile::AliasIdxBot);
2543 
2544   Node* prev_mem = nullptr;
2545   if (wide_in) {
2546     prev_mem = set_predefined_input_for_runtime_call(call);
2547   } else {
2548     assert(!wide_out, "narrow in => narrow out");
2549     Node* narrow_mem = memory(adr_type);
2550     prev_mem = set_predefined_input_for_runtime_call(call, narrow_mem);
2551   }
2552 
2553   // Hook each parm in order.  Stop looking at the first null.
2554   if (parm0 != nullptr) { call->init_req(TypeFunc::Parms+0, parm0);
2555   if (parm1 != nullptr) { call->init_req(TypeFunc::Parms+1, parm1);
2556   if (parm2 != nullptr) { call->init_req(TypeFunc::Parms+2, parm2);
2557   if (parm3 != nullptr) { call->init_req(TypeFunc::Parms+3, parm3);
2558   if (parm4 != nullptr) { call->init_req(TypeFunc::Parms+4, parm4);
2559   if (parm5 != nullptr) { call->init_req(TypeFunc::Parms+5, parm5);
2560   if (parm6 != nullptr) { call->init_req(TypeFunc::Parms+6, parm6);
2561   if (parm7 != nullptr) { call->init_req(TypeFunc::Parms+7, parm7);
2562   /* close each nested if ===> */  } } } } } } } }
2563   assert(call->in(call->req()-1) != nullptr, "must initialize all parms");
2564 
2565   if (!is_leaf) {
2566     // Non-leaves can block and take safepoints:
2567     add_safepoint_edges(call, ((flags & RC_MUST_THROW) != 0));
2568   }
2569   // Non-leaves can throw exceptions:
2570   if (has_io) {
2571     call->set_req(TypeFunc::I_O, i_o());
2572   }
2573 
2574   if (flags & RC_UNCOMMON) {
2575     // Set the count to a tiny probability.  Cf. Estimate_Block_Frequency.
2576     // (An "if" probability corresponds roughly to an unconditional count.
2577     // Sort of.)
2578     call->set_cnt(PROB_UNLIKELY_MAG(4));
2579   }
2580 
2581   Node* c = _gvn.transform(call);
2582   assert(c == call, "cannot disappear");
2583 
2584   if (wide_out) {
2585     // Slow path call has full side-effects.
2586     set_predefined_output_for_runtime_call(call);
2587   } else {
2588     // Slow path call has few side-effects, and/or sets few values.
2589     set_predefined_output_for_runtime_call(call, prev_mem, adr_type);
2590   }
2591 
2592   if (has_io) {
2593     set_i_o(_gvn.transform(new ProjNode(call, TypeFunc::I_O)));
2594   }
2595   return call;
2596 
2597 }
2598 
2599 // i2b
2600 Node* GraphKit::sign_extend_byte(Node* in) {
2601   Node* tmp = _gvn.transform(new LShiftINode(in, _gvn.intcon(24)));
2602   return _gvn.transform(new RShiftINode(tmp, _gvn.intcon(24)));
2603 }
2604 
2605 // i2s
2606 Node* GraphKit::sign_extend_short(Node* in) {
2607   Node* tmp = _gvn.transform(new LShiftINode(in, _gvn.intcon(16)));
2608   return _gvn.transform(new RShiftINode(tmp, _gvn.intcon(16)));
2609 }
2610 
2611 //------------------------------merge_memory-----------------------------------
2612 // Merge memory from one path into the current memory state.
2613 void GraphKit::merge_memory(Node* new_mem, Node* region, int new_path) {
2614   for (MergeMemStream mms(merged_memory(), new_mem->as_MergeMem()); mms.next_non_empty2(); ) {
2615     Node* old_slice = mms.force_memory();
2616     Node* new_slice = mms.memory2();
2617     if (old_slice != new_slice) {
2618       PhiNode* phi;
2619       if (old_slice->is_Phi() && old_slice->as_Phi()->region() == region) {
2620         if (mms.is_empty()) {
2621           // clone base memory Phi's inputs for this memory slice
2622           assert(old_slice == mms.base_memory(), "sanity");
2623           phi = PhiNode::make(region, nullptr, Type::MEMORY, mms.adr_type(C));
2624           _gvn.set_type(phi, Type::MEMORY);
2625           for (uint i = 1; i < phi->req(); i++) {
2626             phi->init_req(i, old_slice->in(i));
2627           }
2628         } else {
2629           phi = old_slice->as_Phi(); // Phi was generated already
2630         }
2631       } else {
2632         phi = PhiNode::make(region, old_slice, Type::MEMORY, mms.adr_type(C));
2633         _gvn.set_type(phi, Type::MEMORY);
2634       }
2635       phi->set_req(new_path, new_slice);
2636       mms.set_memory(phi);
2637     }
2638   }
2639 }
2640 
2641 //------------------------------make_slow_call_ex------------------------------
2642 // Make the exception handler hookups for the slow call
2643 void GraphKit::make_slow_call_ex(Node* call, ciInstanceKlass* ex_klass, bool separate_io_proj, bool deoptimize) {
2644   if (stopped())  return;
2645 
2646   // Make a catch node with just two handlers:  fall-through and catch-all
2647   Node* i_o  = _gvn.transform( new ProjNode(call, TypeFunc::I_O, separate_io_proj) );
2648   Node* catc = _gvn.transform( new CatchNode(control(), i_o, 2) );
2649   Node* norm = new CatchProjNode(catc, CatchProjNode::fall_through_index, CatchProjNode::no_handler_bci);
2650   _gvn.set_type_bottom(norm);
2651   C->record_for_igvn(norm);
2652   Node* excp = _gvn.transform( new CatchProjNode(catc, CatchProjNode::catch_all_index,    CatchProjNode::no_handler_bci) );
2653 
2654   { PreserveJVMState pjvms(this);
2655     set_control(excp);
2656     set_i_o(i_o);
2657 
2658     if (excp != top()) {
2659       if (deoptimize) {
2660         // Deoptimize if an exception is caught. Don't construct exception state in this case.
2661         uncommon_trap(Deoptimization::Reason_unhandled,
2662                       Deoptimization::Action_none);
2663       } else {
2664         // Create an exception state also.
2665         // Use an exact type if the caller has a specific exception.
2666         const Type* ex_type = TypeOopPtr::make_from_klass_unique(ex_klass)->cast_to_ptr_type(TypePtr::NotNull);
2667         Node*       ex_oop  = new CreateExNode(ex_type, control(), i_o);
2668         add_exception_state(make_exception_state(_gvn.transform(ex_oop)));
2669       }
2670     }
2671   }
2672 
2673   // Get the no-exception control from the CatchNode.
2674   set_control(norm);
2675 }
2676 
2677 static IfNode* gen_subtype_check_compare(Node* ctrl, Node* in1, Node* in2, BoolTest::mask test, float p, PhaseGVN& gvn, BasicType bt) {
2678   Node* cmp = nullptr;
2679   switch(bt) {
2680   case T_INT: cmp = new CmpINode(in1, in2); break;
2681   case T_ADDRESS: cmp = new CmpPNode(in1, in2); break;
2682   default: fatal("unexpected comparison type %s", type2name(bt));
2683   }
2684   cmp = gvn.transform(cmp);
2685   Node* bol = gvn.transform(new BoolNode(cmp, test));
2686   IfNode* iff = new IfNode(ctrl, bol, p, COUNT_UNKNOWN);
2687   gvn.transform(iff);
2688   if (!bol->is_Con()) gvn.record_for_igvn(iff);
2689   return iff;
2690 }
2691 
2692 //-------------------------------gen_subtype_check-----------------------------
2693 // Generate a subtyping check.  Takes as input the subtype and supertype.
2694 // Returns 2 values: sets the default control() to the true path and returns
2695 // the false path.  Only reads invariant memory; sets no (visible) memory.
2696 // The PartialSubtypeCheckNode sets the hidden 1-word cache in the encoding
2697 // but that's not exposed to the optimizer.  This call also doesn't take in an
2698 // Object; if you wish to check an Object you need to load the Object's class
2699 // prior to coming here.
2700 Node* Phase::gen_subtype_check(Node* subklass, Node* superklass, Node** ctrl, Node* mem, PhaseGVN& gvn,
2701                                ciMethod* method, int bci) {
2702   Compile* C = gvn.C;
2703   if ((*ctrl)->is_top()) {
2704     return C->top();
2705   }
2706 
2707   // Fast check for identical types, perhaps identical constants.
2708   // The types can even be identical non-constants, in cases
2709   // involving Array.newInstance, Object.clone, etc.
2710   if (subklass == superklass)
2711     return C->top();             // false path is dead; no test needed.
2712 
2713   if (gvn.type(superklass)->singleton()) {
2714     const TypeKlassPtr* superk = gvn.type(superklass)->is_klassptr();
2715     const TypeKlassPtr* subk   = gvn.type(subklass)->is_klassptr();
2716 
2717     // In the common case of an exact superklass, try to fold up the
2718     // test before generating code.  You may ask, why not just generate
2719     // the code and then let it fold up?  The answer is that the generated
2720     // code will necessarily include null checks, which do not always
2721     // completely fold away.  If they are also needless, then they turn
2722     // into a performance loss.  Example:
2723     //    Foo[] fa = blah(); Foo x = fa[0]; fa[1] = x;
2724     // Here, the type of 'fa' is often exact, so the store check
2725     // of fa[1]=x will fold up, without testing the nullness of x.
2726     //
2727     // At macro expansion, we would have already folded the SubTypeCheckNode
2728     // being expanded here because we always perform the static sub type
2729     // check in SubTypeCheckNode::sub() regardless of whether
2730     // StressReflectiveCode is set or not. We can therefore skip this
2731     // static check when StressReflectiveCode is on.
2732     switch (C->static_subtype_check(superk, subk)) {
2733     case Compile::SSC_always_false:
2734       {
2735         Node* always_fail = *ctrl;
2736         *ctrl = gvn.C->top();
2737         return always_fail;
2738       }
2739     case Compile::SSC_always_true:
2740       return C->top();
2741     case Compile::SSC_easy_test:
2742       {
2743         // Just do a direct pointer compare and be done.
2744         IfNode* iff = gen_subtype_check_compare(*ctrl, subklass, superklass, BoolTest::eq, PROB_STATIC_FREQUENT, gvn, T_ADDRESS);
2745         *ctrl = gvn.transform(new IfTrueNode(iff));
2746         return gvn.transform(new IfFalseNode(iff));
2747       }
2748     case Compile::SSC_full_test:
2749       break;
2750     default:
2751       ShouldNotReachHere();
2752     }
2753   }
2754 
2755   // %%% Possible further optimization:  Even if the superklass is not exact,
2756   // if the subklass is the unique subtype of the superklass, the check
2757   // will always succeed.  We could leave a dependency behind to ensure this.
2758 
2759   // First load the super-klass's check-offset
2760   Node *p1 = gvn.transform(new AddPNode(C->top(), superklass, gvn.MakeConX(in_bytes(Klass::super_check_offset_offset()))));
2761   Node* m = C->immutable_memory();
2762   Node *chk_off = gvn.transform(new LoadINode(nullptr, m, p1, gvn.type(p1)->is_ptr(), TypeInt::INT, MemNode::unordered));
2763   int cacheoff_con = in_bytes(Klass::secondary_super_cache_offset());
2764   const TypeInt* chk_off_t = chk_off->Value(&gvn)->isa_int();
2765   int chk_off_con = (chk_off_t != nullptr && chk_off_t->is_con()) ? chk_off_t->get_con() : cacheoff_con;
2766   bool might_be_cache = (chk_off_con == cacheoff_con);
2767 
2768   // Load from the sub-klass's super-class display list, or a 1-word cache of
2769   // the secondary superclass list, or a failing value with a sentinel offset
2770   // if the super-klass is an interface or exceptionally deep in the Java
2771   // hierarchy and we have to scan the secondary superclass list the hard way.
2772   // Worst-case type is a little odd: null is allowed as a result (usually
2773   // klass loads can never produce a null).
2774   Node *chk_off_X = chk_off;
2775 #ifdef _LP64
2776   chk_off_X = gvn.transform(new ConvI2LNode(chk_off_X));
2777 #endif
2778   Node* p2 = gvn.transform(new AddPNode(C->top(), subklass, chk_off_X));
2779   // For some types like interfaces the following loadKlass is from a 1-word
2780   // cache which is mutable so can't use immutable memory.  Other
2781   // types load from the super-class display table which is immutable.
2782   Node *kmem = C->immutable_memory();
2783   // secondary_super_cache is not immutable but can be treated as such because:
2784   // - no ideal node writes to it in a way that could cause an
2785   //   incorrect/missed optimization of the following Load.
2786   // - it's a cache so, worse case, not reading the latest value
2787   //   wouldn't cause incorrect execution
2788   if (might_be_cache && mem != nullptr) {
2789     kmem = mem->is_MergeMem() ? mem->as_MergeMem()->memory_at(C->get_alias_index(gvn.type(p2)->is_ptr())) : mem;
2790   }
2791   Node* nkls = gvn.transform(LoadKlassNode::make(gvn, kmem, p2, gvn.type(p2)->is_ptr(), TypeInstKlassPtr::OBJECT_OR_NULL));
2792 
2793   // Compile speed common case: ARE a subtype and we canNOT fail
2794   if (superklass == nkls) {
2795     return C->top();             // false path is dead; no test needed.
2796   }
2797 
2798   // Gather the various success & failures here
2799   RegionNode* r_not_subtype = new RegionNode(3);
2800   gvn.record_for_igvn(r_not_subtype);
2801   RegionNode* r_ok_subtype = new RegionNode(4);
2802   gvn.record_for_igvn(r_ok_subtype);
2803 
2804   // If we might perform an expensive check, first try to take advantage of profile data that was attached to the
2805   // SubTypeCheck node
2806   if (might_be_cache && method != nullptr && VM_Version::profile_all_receivers_at_type_check()) {
2807     ciCallProfile profile = method->call_profile_at_bci(bci);
2808     float total_prob = 0;
2809     for (int i = 0; profile.has_receiver(i); ++i) {
2810       float prob = profile.receiver_prob(i);
2811       total_prob += prob;
2812     }
2813     if (total_prob * 100. >= TypeProfileSubTypeCheckCommonThreshold) {
2814       const TypeKlassPtr* superk = gvn.type(superklass)->is_klassptr();
2815       for (int i = 0; profile.has_receiver(i); ++i) {
2816         ciKlass* klass = profile.receiver(i);
2817         const TypeKlassPtr* klass_t = TypeKlassPtr::make(klass);
2818         Compile::SubTypeCheckResult result = C->static_subtype_check(superk, klass_t);
2819         if (result != Compile::SSC_always_true && result != Compile::SSC_always_false) {
2820           continue;
2821         }
2822         float prob = profile.receiver_prob(i);
2823         ConNode* klass_node = gvn.makecon(klass_t);
2824         IfNode* iff = gen_subtype_check_compare(*ctrl, subklass, klass_node, BoolTest::eq, prob, gvn, T_ADDRESS);
2825         Node* iftrue = gvn.transform(new IfTrueNode(iff));
2826 
2827         if (result == Compile::SSC_always_true) {
2828           r_ok_subtype->add_req(iftrue);
2829         } else {
2830           assert(result == Compile::SSC_always_false, "");
2831           r_not_subtype->add_req(iftrue);
2832         }
2833         *ctrl = gvn.transform(new IfFalseNode(iff));
2834       }
2835     }
2836   }
2837 
2838   // See if we get an immediate positive hit.  Happens roughly 83% of the
2839   // time.  Test to see if the value loaded just previously from the subklass
2840   // is exactly the superklass.
2841   IfNode *iff1 = gen_subtype_check_compare(*ctrl, superklass, nkls, BoolTest::eq, PROB_LIKELY(0.83f), gvn, T_ADDRESS);
2842   Node *iftrue1 = gvn.transform( new IfTrueNode (iff1));
2843   *ctrl = gvn.transform(new IfFalseNode(iff1));
2844 
2845   // Compile speed common case: Check for being deterministic right now.  If
2846   // chk_off is a constant and not equal to cacheoff then we are NOT a
2847   // subklass.  In this case we need exactly the 1 test above and we can
2848   // return those results immediately.
2849   if (!might_be_cache) {
2850     Node* not_subtype_ctrl = *ctrl;
2851     *ctrl = iftrue1; // We need exactly the 1 test above
2852     PhaseIterGVN* igvn = gvn.is_IterGVN();
2853     if (igvn != nullptr) {
2854       igvn->remove_globally_dead_node(r_ok_subtype);
2855       igvn->remove_globally_dead_node(r_not_subtype);
2856     }
2857     return not_subtype_ctrl;
2858   }
2859 
2860   r_ok_subtype->init_req(1, iftrue1);
2861 
2862   // Check for immediate negative hit.  Happens roughly 11% of the time (which
2863   // is roughly 63% of the remaining cases).  Test to see if the loaded
2864   // check-offset points into the subklass display list or the 1-element
2865   // cache.  If it points to the display (and NOT the cache) and the display
2866   // missed then it's not a subtype.
2867   Node *cacheoff = gvn.intcon(cacheoff_con);
2868   IfNode *iff2 = gen_subtype_check_compare(*ctrl, chk_off, cacheoff, BoolTest::ne, PROB_LIKELY(0.63f), gvn, T_INT);
2869   r_not_subtype->init_req(1, gvn.transform(new IfTrueNode (iff2)));
2870   *ctrl = gvn.transform(new IfFalseNode(iff2));
2871 
2872   // Check for self.  Very rare to get here, but it is taken 1/3 the time.
2873   // No performance impact (too rare) but allows sharing of secondary arrays
2874   // which has some footprint reduction.
2875   IfNode *iff3 = gen_subtype_check_compare(*ctrl, subklass, superklass, BoolTest::eq, PROB_LIKELY(0.36f), gvn, T_ADDRESS);
2876   r_ok_subtype->init_req(2, gvn.transform(new IfTrueNode(iff3)));
2877   *ctrl = gvn.transform(new IfFalseNode(iff3));
2878 
2879   // -- Roads not taken here: --
2880   // We could also have chosen to perform the self-check at the beginning
2881   // of this code sequence, as the assembler does.  This would not pay off
2882   // the same way, since the optimizer, unlike the assembler, can perform
2883   // static type analysis to fold away many successful self-checks.
2884   // Non-foldable self checks work better here in second position, because
2885   // the initial primary superclass check subsumes a self-check for most
2886   // types.  An exception would be a secondary type like array-of-interface,
2887   // which does not appear in its own primary supertype display.
2888   // Finally, we could have chosen to move the self-check into the
2889   // PartialSubtypeCheckNode, and from there out-of-line in a platform
2890   // dependent manner.  But it is worthwhile to have the check here,
2891   // where it can be perhaps be optimized.  The cost in code space is
2892   // small (register compare, branch).
2893 
2894   // Now do a linear scan of the secondary super-klass array.  Again, no real
2895   // performance impact (too rare) but it's gotta be done.
2896   // Since the code is rarely used, there is no penalty for moving it
2897   // out of line, and it can only improve I-cache density.
2898   // The decision to inline or out-of-line this final check is platform
2899   // dependent, and is found in the AD file definition of PartialSubtypeCheck.
2900   Node* psc = gvn.transform(
2901     new PartialSubtypeCheckNode(*ctrl, subklass, superklass));
2902 
2903   IfNode *iff4 = gen_subtype_check_compare(*ctrl, psc, gvn.zerocon(T_OBJECT), BoolTest::ne, PROB_FAIR, gvn, T_ADDRESS);
2904   r_not_subtype->init_req(2, gvn.transform(new IfTrueNode (iff4)));
2905   r_ok_subtype ->init_req(3, gvn.transform(new IfFalseNode(iff4)));
2906 
2907   // Return false path; set default control to true path.
2908   *ctrl = gvn.transform(r_ok_subtype);
2909   return gvn.transform(r_not_subtype);
2910 }
2911 
2912 Node* GraphKit::gen_subtype_check(Node* obj_or_subklass, Node* superklass) {
2913   bool expand_subtype_check = C->post_loop_opts_phase(); // macro node expansion is over
2914   if (expand_subtype_check) {
2915     MergeMemNode* mem = merged_memory();
2916     Node* ctrl = control();
2917     Node* subklass = obj_or_subklass;
2918     if (!_gvn.type(obj_or_subklass)->isa_klassptr()) {
2919       subklass = load_object_klass(obj_or_subklass);
2920     }
2921 
2922     Node* n = Phase::gen_subtype_check(subklass, superklass, &ctrl, mem, _gvn, method(), bci());
2923     set_control(ctrl);
2924     return n;
2925   }
2926 
2927   Node* check = _gvn.transform(new SubTypeCheckNode(C, obj_or_subklass, superklass, method(), bci()));
2928   Node* bol = _gvn.transform(new BoolNode(check, BoolTest::eq));
2929   IfNode* iff = create_and_xform_if(control(), bol, PROB_STATIC_FREQUENT, COUNT_UNKNOWN);
2930   set_control(_gvn.transform(new IfTrueNode(iff)));
2931   return _gvn.transform(new IfFalseNode(iff));
2932 }
2933 
2934 // Profile-driven exact type check:
2935 Node* GraphKit::type_check_receiver(Node* receiver, ciKlass* klass,
2936                                     float prob,
2937                                     Node* *casted_receiver) {
2938   assert(!klass->is_interface(), "no exact type check on interfaces");
2939 
2940   const TypeKlassPtr* tklass = TypeKlassPtr::make(klass, Type::trust_interfaces);
2941   Node* recv_klass = load_object_klass(receiver);
2942   Node* want_klass = makecon(tklass);
2943   Node* cmp = _gvn.transform(new CmpPNode(recv_klass, want_klass));
2944   Node* bol = _gvn.transform(new BoolNode(cmp, BoolTest::eq));
2945   IfNode* iff = create_and_xform_if(control(), bol, prob, COUNT_UNKNOWN);
2946   set_control( _gvn.transform(new IfTrueNode (iff)));
2947   Node* fail = _gvn.transform(new IfFalseNode(iff));
2948 
2949   if (!stopped()) {
2950     const TypeOopPtr* receiver_type = _gvn.type(receiver)->isa_oopptr();
2951     const TypeOopPtr* recvx_type = tklass->as_instance_type();
2952     assert(recvx_type->klass_is_exact(), "");
2953 
2954     if (!receiver_type->higher_equal(recvx_type)) { // ignore redundant casts
2955       // Subsume downstream occurrences of receiver with a cast to
2956       // recv_xtype, since now we know what the type will be.
2957       Node* cast = new CheckCastPPNode(control(), receiver, recvx_type);
2958       (*casted_receiver) = _gvn.transform(cast);
2959       assert(!(*casted_receiver)->is_top(), "that path should be unreachable");
2960       // (User must make the replace_in_map call.)
2961     }
2962   }
2963 
2964   return fail;
2965 }
2966 
2967 //------------------------------subtype_check_receiver-------------------------
2968 Node* GraphKit::subtype_check_receiver(Node* receiver, ciKlass* klass,
2969                                        Node** casted_receiver) {
2970   const TypeKlassPtr* tklass = TypeKlassPtr::make(klass, Type::trust_interfaces)->try_improve();
2971   Node* want_klass = makecon(tklass);
2972 
2973   Node* slow_ctl = gen_subtype_check(receiver, want_klass);
2974 
2975   // Ignore interface type information until interface types are properly tracked.
2976   if (!stopped() && !klass->is_interface()) {
2977     const TypeOopPtr* receiver_type = _gvn.type(receiver)->isa_oopptr();
2978     const TypeOopPtr* recv_type = tklass->cast_to_exactness(false)->is_klassptr()->as_instance_type();
2979     if (!receiver_type->higher_equal(recv_type)) { // ignore redundant casts
2980       Node* cast = new CheckCastPPNode(control(), receiver, recv_type);
2981       (*casted_receiver) = _gvn.transform(cast);
2982     }
2983   }
2984 
2985   return slow_ctl;
2986 }
2987 
2988 //------------------------------seems_never_null-------------------------------
2989 // Use null_seen information if it is available from the profile.
2990 // If we see an unexpected null at a type check we record it and force a
2991 // recompile; the offending check will be recompiled to handle nulls.
2992 // If we see several offending BCIs, then all checks in the
2993 // method will be recompiled.
2994 bool GraphKit::seems_never_null(Node* obj, ciProfileData* data, bool& speculating) {
2995   speculating = !_gvn.type(obj)->speculative_maybe_null();
2996   Deoptimization::DeoptReason reason = Deoptimization::reason_null_check(speculating);
2997   if (UncommonNullCast               // Cutout for this technique
2998       && obj != null()               // And not the -Xcomp stupid case?
2999       && !too_many_traps(reason)
3000       ) {
3001     if (speculating) {
3002       return true;
3003     }
3004     if (data == nullptr)
3005       // Edge case:  no mature data.  Be optimistic here.
3006       return true;
3007     // If the profile has not seen a null, assume it won't happen.
3008     assert(java_bc() == Bytecodes::_checkcast ||
3009            java_bc() == Bytecodes::_instanceof ||
3010            java_bc() == Bytecodes::_aastore, "MDO must collect null_seen bit here");
3011     return !data->as_BitData()->null_seen();
3012   }
3013   speculating = false;
3014   return false;
3015 }
3016 
3017 void GraphKit::guard_klass_being_initialized(Node* klass) {
3018   int init_state_off = in_bytes(InstanceKlass::init_state_offset());
3019   Node* adr = basic_plus_adr(top(), klass, init_state_off);
3020   Node* init_state = LoadNode::make(_gvn, nullptr, immutable_memory(), adr,
3021                                     adr->bottom_type()->is_ptr(), TypeInt::BYTE,
3022                                     T_BYTE, MemNode::acquire);
3023   init_state = _gvn.transform(init_state);
3024 
3025   Node* being_initialized_state = makecon(TypeInt::make(InstanceKlass::being_initialized));
3026 
3027   Node* chk = _gvn.transform(new CmpINode(being_initialized_state, init_state));
3028   Node* tst = _gvn.transform(new BoolNode(chk, BoolTest::eq));
3029 
3030   { BuildCutout unless(this, tst, PROB_MAX);
3031     uncommon_trap(Deoptimization::Reason_initialized, Deoptimization::Action_reinterpret);
3032   }
3033 }
3034 
3035 void GraphKit::guard_init_thread(Node* klass) {
3036   int init_thread_off = in_bytes(InstanceKlass::init_thread_offset());
3037   Node* adr = basic_plus_adr(top(), klass, init_thread_off);
3038 
3039   Node* init_thread = LoadNode::make(_gvn, nullptr, immutable_memory(), adr,
3040                                      adr->bottom_type()->is_ptr(), TypePtr::NOTNULL,
3041                                      T_ADDRESS, MemNode::unordered);
3042   init_thread = _gvn.transform(init_thread);
3043 
3044   Node* cur_thread = _gvn.transform(new ThreadLocalNode());
3045 
3046   Node* chk = _gvn.transform(new CmpPNode(cur_thread, init_thread));
3047   Node* tst = _gvn.transform(new BoolNode(chk, BoolTest::eq));
3048 
3049   { BuildCutout unless(this, tst, PROB_MAX);
3050     uncommon_trap(Deoptimization::Reason_uninitialized, Deoptimization::Action_none);
3051   }
3052 }
3053 
3054 void GraphKit::clinit_barrier(ciInstanceKlass* ik, ciMethod* context) {
3055   if (ik->is_being_initialized()) {
3056     if (C->needs_clinit_barrier(ik, context)) {
3057       Node* klass = makecon(TypeKlassPtr::make(ik));
3058       guard_klass_being_initialized(klass);
3059       guard_init_thread(klass);
3060       insert_mem_bar(Op_MemBarCPUOrder);
3061     }
3062   } else if (ik->is_initialized()) {
3063     return; // no barrier needed
3064   } else {
3065     uncommon_trap(Deoptimization::Reason_uninitialized,
3066                   Deoptimization::Action_reinterpret,
3067                   nullptr);
3068   }
3069 }
3070 
3071 //------------------------maybe_cast_profiled_receiver-------------------------
3072 // If the profile has seen exactly one type, narrow to exactly that type.
3073 // Subsequent type checks will always fold up.
3074 Node* GraphKit::maybe_cast_profiled_receiver(Node* not_null_obj,
3075                                              const TypeKlassPtr* require_klass,
3076                                              ciKlass* spec_klass,
3077                                              bool safe_for_replace) {
3078   if (!UseTypeProfile || !TypeProfileCasts) return nullptr;
3079 
3080   Deoptimization::DeoptReason reason = Deoptimization::reason_class_check(spec_klass != nullptr);
3081 
3082   // Make sure we haven't already deoptimized from this tactic.
3083   if (too_many_traps_or_recompiles(reason))
3084     return nullptr;
3085 
3086   // (No, this isn't a call, but it's enough like a virtual call
3087   // to use the same ciMethod accessor to get the profile info...)
3088   // If we have a speculative type use it instead of profiling (which
3089   // may not help us)
3090   ciKlass* exact_kls = spec_klass == nullptr ? profile_has_unique_klass() : spec_klass;
3091   if (exact_kls != nullptr) {// no cast failures here
3092     if (require_klass == nullptr ||
3093         C->static_subtype_check(require_klass, TypeKlassPtr::make(exact_kls, Type::trust_interfaces)) == Compile::SSC_always_true) {
3094       // If we narrow the type to match what the type profile sees or
3095       // the speculative type, we can then remove the rest of the
3096       // cast.
3097       // This is a win, even if the exact_kls is very specific,
3098       // because downstream operations, such as method calls,
3099       // will often benefit from the sharper type.
3100       Node* exact_obj = not_null_obj; // will get updated in place...
3101       Node* slow_ctl  = type_check_receiver(exact_obj, exact_kls, 1.0,
3102                                             &exact_obj);
3103       { PreserveJVMState pjvms(this);
3104         set_control(slow_ctl);
3105         uncommon_trap_exact(reason, Deoptimization::Action_maybe_recompile);
3106       }
3107       if (safe_for_replace) {
3108         replace_in_map(not_null_obj, exact_obj);
3109       }
3110       return exact_obj;
3111     }
3112     // assert(ssc == Compile::SSC_always_true)... except maybe the profile lied to us.
3113   }
3114 
3115   return nullptr;
3116 }
3117 
3118 /**
3119  * Cast obj to type and emit guard unless we had too many traps here
3120  * already
3121  *
3122  * @param obj       node being casted
3123  * @param type      type to cast the node to
3124  * @param not_null  true if we know node cannot be null
3125  */
3126 Node* GraphKit::maybe_cast_profiled_obj(Node* obj,
3127                                         ciKlass* type,
3128                                         bool not_null) {
3129   if (stopped()) {
3130     return obj;
3131   }
3132 
3133   // type is null if profiling tells us this object is always null
3134   if (type != nullptr) {
3135     Deoptimization::DeoptReason class_reason = Deoptimization::Reason_speculate_class_check;
3136     Deoptimization::DeoptReason null_reason = Deoptimization::Reason_speculate_null_check;
3137 
3138     if (!too_many_traps_or_recompiles(null_reason) &&
3139         !too_many_traps_or_recompiles(class_reason)) {
3140       Node* not_null_obj = nullptr;
3141       // not_null is true if we know the object is not null and
3142       // there's no need for a null check
3143       if (!not_null) {
3144         Node* null_ctl = top();
3145         not_null_obj = null_check_oop(obj, &null_ctl, true, true, true);
3146         assert(null_ctl->is_top(), "no null control here");
3147       } else {
3148         not_null_obj = obj;
3149       }
3150 
3151       Node* exact_obj = not_null_obj;
3152       ciKlass* exact_kls = type;
3153       Node* slow_ctl  = type_check_receiver(exact_obj, exact_kls, 1.0,
3154                                             &exact_obj);
3155       {
3156         PreserveJVMState pjvms(this);
3157         set_control(slow_ctl);
3158         uncommon_trap_exact(class_reason, Deoptimization::Action_maybe_recompile);
3159       }
3160       replace_in_map(not_null_obj, exact_obj);
3161       obj = exact_obj;
3162     }
3163   } else {
3164     if (!too_many_traps_or_recompiles(Deoptimization::Reason_null_assert)) {
3165       Node* exact_obj = null_assert(obj);
3166       replace_in_map(obj, exact_obj);
3167       obj = exact_obj;
3168     }
3169   }
3170   return obj;
3171 }
3172 
3173 //-------------------------------gen_instanceof--------------------------------
3174 // Generate an instance-of idiom.  Used by both the instance-of bytecode
3175 // and the reflective instance-of call.
3176 Node* GraphKit::gen_instanceof(Node* obj, Node* superklass, bool safe_for_replace) {
3177   kill_dead_locals();           // Benefit all the uncommon traps
3178   assert( !stopped(), "dead parse path should be checked in callers" );
3179   assert(!TypePtr::NULL_PTR->higher_equal(_gvn.type(superklass)->is_klassptr()),
3180          "must check for not-null not-dead klass in callers");
3181 
3182   // Make the merge point
3183   enum { _obj_path = 1, _fail_path, _null_path, PATH_LIMIT };
3184   RegionNode* region = new RegionNode(PATH_LIMIT);
3185   Node*       phi    = new PhiNode(region, TypeInt::BOOL);
3186   C->set_has_split_ifs(true); // Has chance for split-if optimization
3187 
3188   ciProfileData* data = nullptr;
3189   if (java_bc() == Bytecodes::_instanceof) {  // Only for the bytecode
3190     data = method()->method_data()->bci_to_data(bci());
3191   }
3192   bool speculative_not_null = false;
3193   bool never_see_null = (ProfileDynamicTypes  // aggressive use of profile
3194                          && seems_never_null(obj, data, speculative_not_null));
3195 
3196   // Null check; get casted pointer; set region slot 3
3197   Node* null_ctl = top();
3198   Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null, safe_for_replace, speculative_not_null);
3199 
3200   // If not_null_obj is dead, only null-path is taken
3201   if (stopped()) {              // Doing instance-of on a null?
3202     set_control(null_ctl);
3203     return intcon(0);
3204   }
3205   region->init_req(_null_path, null_ctl);
3206   phi   ->init_req(_null_path, intcon(0)); // Set null path value
3207   if (null_ctl == top()) {
3208     // Do this eagerly, so that pattern matches like is_diamond_phi
3209     // will work even during parsing.
3210     assert(_null_path == PATH_LIMIT-1, "delete last");
3211     region->del_req(_null_path);
3212     phi   ->del_req(_null_path);
3213   }
3214 
3215   // Do we know the type check always succeed?
3216   bool known_statically = false;
3217   if (_gvn.type(superklass)->singleton()) {
3218     const TypeKlassPtr* superk = _gvn.type(superklass)->is_klassptr();
3219     const TypeKlassPtr* subk = _gvn.type(obj)->is_oopptr()->as_klass_type();
3220     if (subk->is_loaded()) {
3221       int static_res = C->static_subtype_check(superk, subk);
3222       known_statically = (static_res == Compile::SSC_always_true || static_res == Compile::SSC_always_false);
3223     }
3224   }
3225 
3226   if (!known_statically) {
3227     const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
3228     // We may not have profiling here or it may not help us. If we
3229     // have a speculative type use it to perform an exact cast.
3230     ciKlass* spec_obj_type = obj_type->speculative_type();
3231     if (spec_obj_type != nullptr || (ProfileDynamicTypes && data != nullptr)) {
3232       Node* cast_obj = maybe_cast_profiled_receiver(not_null_obj, nullptr, spec_obj_type, safe_for_replace);
3233       if (stopped()) {            // Profile disagrees with this path.
3234         set_control(null_ctl);    // Null is the only remaining possibility.
3235         return intcon(0);
3236       }
3237       if (cast_obj != nullptr) {
3238         not_null_obj = cast_obj;
3239       }
3240     }
3241   }
3242 
3243   // Generate the subtype check
3244   Node* not_subtype_ctrl = gen_subtype_check(not_null_obj, superklass);
3245 
3246   // Plug in the success path to the general merge in slot 1.
3247   region->init_req(_obj_path, control());
3248   phi   ->init_req(_obj_path, intcon(1));
3249 
3250   // Plug in the failing path to the general merge in slot 2.
3251   region->init_req(_fail_path, not_subtype_ctrl);
3252   phi   ->init_req(_fail_path, intcon(0));
3253 
3254   // Return final merged results
3255   set_control( _gvn.transform(region) );
3256   record_for_igvn(region);
3257 
3258   // If we know the type check always succeeds then we don't use the
3259   // profiling data at this bytecode. Don't lose it, feed it to the
3260   // type system as a speculative type.
3261   if (safe_for_replace) {
3262     Node* casted_obj = record_profiled_receiver_for_speculation(obj);
3263     replace_in_map(obj, casted_obj);
3264   }
3265 
3266   return _gvn.transform(phi);
3267 }
3268 
3269 //-------------------------------gen_checkcast---------------------------------
3270 // Generate a checkcast idiom.  Used by both the checkcast bytecode and the
3271 // array store bytecode.  Stack must be as-if BEFORE doing the bytecode so the
3272 // uncommon-trap paths work.  Adjust stack after this call.
3273 // If failure_control is supplied and not null, it is filled in with
3274 // the control edge for the cast failure.  Otherwise, an appropriate
3275 // uncommon trap or exception is thrown.
3276 Node* GraphKit::gen_checkcast(Node *obj, Node* superklass,
3277                               Node* *failure_control) {
3278   kill_dead_locals();           // Benefit all the uncommon traps
3279   const TypeKlassPtr* klass_ptr_type = _gvn.type(superklass)->is_klassptr();
3280   const TypeKlassPtr* improved_klass_ptr_type = klass_ptr_type->try_improve();
3281   const TypeOopPtr* toop = improved_klass_ptr_type->cast_to_exactness(false)->as_instance_type();
3282 
3283   // Fast cutout:  Check the case that the cast is vacuously true.
3284   // This detects the common cases where the test will short-circuit
3285   // away completely.  We do this before we perform the null check,
3286   // because if the test is going to turn into zero code, we don't
3287   // want a residual null check left around.  (Causes a slowdown,
3288   // for example, in some objArray manipulations, such as a[i]=a[j].)
3289   if (improved_klass_ptr_type->singleton()) {
3290     const TypeOopPtr* objtp = _gvn.type(obj)->isa_oopptr();
3291     if (objtp != nullptr) {
3292       switch (C->static_subtype_check(improved_klass_ptr_type, objtp->as_klass_type())) {
3293       case Compile::SSC_always_true:
3294         // If we know the type check always succeed then we don't use
3295         // the profiling data at this bytecode. Don't lose it, feed it
3296         // to the type system as a speculative type.
3297         return record_profiled_receiver_for_speculation(obj);
3298       case Compile::SSC_always_false:
3299         // It needs a null check because a null will *pass* the cast check.
3300         // A non-null value will always produce an exception.
3301         if (!objtp->maybe_null()) {
3302           bool is_aastore = (java_bc() == Bytecodes::_aastore);
3303           Deoptimization::DeoptReason reason = is_aastore ?
3304             Deoptimization::Reason_array_check : Deoptimization::Reason_class_check;
3305           builtin_throw(reason);
3306           return top();
3307         } else if (!too_many_traps_or_recompiles(Deoptimization::Reason_null_assert)) {
3308           return null_assert(obj);
3309         }
3310         break; // Fall through to full check
3311       default:
3312         break;
3313       }
3314     }
3315   }
3316 
3317   ciProfileData* data = nullptr;
3318   bool safe_for_replace = false;
3319   if (failure_control == nullptr) {        // use MDO in regular case only
3320     assert(java_bc() == Bytecodes::_aastore ||
3321            java_bc() == Bytecodes::_checkcast,
3322            "interpreter profiles type checks only for these BCs");
3323     data = method()->method_data()->bci_to_data(bci());
3324     safe_for_replace = true;
3325   }
3326 
3327   // Make the merge point
3328   enum { _obj_path = 1, _null_path, PATH_LIMIT };
3329   RegionNode* region = new RegionNode(PATH_LIMIT);
3330   Node*       phi    = new PhiNode(region, toop);
3331   C->set_has_split_ifs(true); // Has chance for split-if optimization
3332 
3333   // Use null-cast information if it is available
3334   bool speculative_not_null = false;
3335   bool never_see_null = ((failure_control == nullptr)  // regular case only
3336                          && seems_never_null(obj, data, speculative_not_null));
3337 
3338   // Null check; get casted pointer; set region slot 3
3339   Node* null_ctl = top();
3340   Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null, safe_for_replace, speculative_not_null);
3341 
3342   // If not_null_obj is dead, only null-path is taken
3343   if (stopped()) {              // Doing instance-of on a null?
3344     set_control(null_ctl);
3345     return null();
3346   }
3347   region->init_req(_null_path, null_ctl);
3348   phi   ->init_req(_null_path, null());  // Set null path value
3349   if (null_ctl == top()) {
3350     // Do this eagerly, so that pattern matches like is_diamond_phi
3351     // will work even during parsing.
3352     assert(_null_path == PATH_LIMIT-1, "delete last");
3353     region->del_req(_null_path);
3354     phi   ->del_req(_null_path);
3355   }
3356 
3357   Node* cast_obj = nullptr;
3358   if (improved_klass_ptr_type->klass_is_exact()) {
3359     // The following optimization tries to statically cast the speculative type of the object
3360     // (for example obtained during profiling) to the type of the superklass and then do a
3361     // dynamic check that the type of the object is what we expect. To work correctly
3362     // for checkcast and aastore the type of superklass should be exact.
3363     const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
3364     // We may not have profiling here or it may not help us. If we have
3365     // a speculative type use it to perform an exact cast.
3366     ciKlass* spec_obj_type = obj_type->speculative_type();
3367     if (spec_obj_type != nullptr || data != nullptr) {
3368       cast_obj = maybe_cast_profiled_receiver(not_null_obj, improved_klass_ptr_type, spec_obj_type, safe_for_replace);
3369       if (cast_obj != nullptr) {
3370         if (failure_control != nullptr) // failure is now impossible
3371           (*failure_control) = top();
3372         // adjust the type of the phi to the exact klass:
3373         phi->raise_bottom_type(_gvn.type(cast_obj)->meet_speculative(TypePtr::NULL_PTR));
3374       }
3375     }
3376   }
3377 
3378   if (cast_obj == nullptr) {
3379     // Generate the subtype check
3380     Node* improved_superklass = superklass;
3381     if (improved_klass_ptr_type != klass_ptr_type && improved_klass_ptr_type->singleton()) {
3382       improved_superklass = makecon(improved_klass_ptr_type);
3383     }
3384     Node* not_subtype_ctrl = gen_subtype_check(not_null_obj, improved_superklass);
3385 
3386     // Plug in success path into the merge
3387     cast_obj = _gvn.transform(new CheckCastPPNode(control(), not_null_obj, toop));
3388     // Failure path ends in uncommon trap (or may be dead - failure impossible)
3389     if (failure_control == nullptr) {
3390       if (not_subtype_ctrl != top()) { // If failure is possible
3391         PreserveJVMState pjvms(this);
3392         set_control(not_subtype_ctrl);
3393         bool is_aastore = (java_bc() == Bytecodes::_aastore);
3394         Deoptimization::DeoptReason reason = is_aastore ?
3395           Deoptimization::Reason_array_check : Deoptimization::Reason_class_check;
3396         builtin_throw(reason);
3397       }
3398     } else {
3399       (*failure_control) = not_subtype_ctrl;
3400     }
3401   }
3402 
3403   region->init_req(_obj_path, control());
3404   phi   ->init_req(_obj_path, cast_obj);
3405 
3406   // A merge of null or Casted-NotNull obj
3407   Node* res = _gvn.transform(phi);
3408 
3409   // Note I do NOT always 'replace_in_map(obj,result)' here.
3410   //  if( tk->klass()->can_be_primary_super()  )
3411     // This means that if I successfully store an Object into an array-of-String
3412     // I 'forget' that the Object is really now known to be a String.  I have to
3413     // do this because we don't have true union types for interfaces - if I store
3414     // a Baz into an array-of-Interface and then tell the optimizer it's an
3415     // Interface, I forget that it's also a Baz and cannot do Baz-like field
3416     // references to it.  FIX THIS WHEN UNION TYPES APPEAR!
3417   //  replace_in_map( obj, res );
3418 
3419   // Return final merged results
3420   set_control( _gvn.transform(region) );
3421   record_for_igvn(region);
3422 
3423   return record_profiled_receiver_for_speculation(res);
3424 }
3425 
3426 //------------------------------next_monitor-----------------------------------
3427 // What number should be given to the next monitor?
3428 int GraphKit::next_monitor() {
3429   int current = jvms()->monitor_depth()* C->sync_stack_slots();
3430   int next = current + C->sync_stack_slots();
3431   // Keep the toplevel high water mark current:
3432   if (C->fixed_slots() < next)  C->set_fixed_slots(next);
3433   return current;
3434 }
3435 
3436 //------------------------------insert_mem_bar---------------------------------
3437 // Memory barrier to avoid floating things around
3438 // The membar serves as a pinch point between both control and all memory slices.
3439 Node* GraphKit::insert_mem_bar(int opcode, Node* precedent) {
3440   MemBarNode* mb = MemBarNode::make(C, opcode, Compile::AliasIdxBot, precedent);
3441   mb->init_req(TypeFunc::Control, control());
3442   mb->init_req(TypeFunc::Memory,  reset_memory());
3443   Node* membar = _gvn.transform(mb);
3444   record_for_igvn(membar);
3445   set_control(_gvn.transform(new ProjNode(membar, TypeFunc::Control)));
3446   set_all_memory_call(membar);
3447   return membar;
3448 }
3449 
3450 //-------------------------insert_mem_bar_volatile----------------------------
3451 // Memory barrier to avoid floating things around
3452 // The membar serves as a pinch point between both control and memory(alias_idx).
3453 // If you want to make a pinch point on all memory slices, do not use this
3454 // function (even with AliasIdxBot); use insert_mem_bar() instead.
3455 Node* GraphKit::insert_mem_bar_volatile(int opcode, int alias_idx, Node* precedent) {
3456   // When Parse::do_put_xxx updates a volatile field, it appends a series
3457   // of MemBarVolatile nodes, one for *each* volatile field alias category.
3458   // The first membar is on the same memory slice as the field store opcode.
3459   // This forces the membar to follow the store.  (Bug 6500685 broke this.)
3460   // All the other membars (for other volatile slices, including AliasIdxBot,
3461   // which stands for all unknown volatile slices) are control-dependent
3462   // on the first membar.  This prevents later volatile loads or stores
3463   // from sliding up past the just-emitted store.
3464 
3465   MemBarNode* mb = MemBarNode::make(C, opcode, alias_idx, precedent);
3466   mb->set_req(TypeFunc::Control,control());
3467   if (alias_idx == Compile::AliasIdxBot) {
3468     mb->set_req(TypeFunc::Memory, merged_memory()->base_memory());
3469   } else {
3470     assert(!(opcode == Op_Initialize && alias_idx != Compile::AliasIdxRaw), "fix caller");
3471     mb->set_req(TypeFunc::Memory, memory(alias_idx));
3472   }
3473   Node* membar = _gvn.transform(mb);
3474   record_for_igvn(membar);
3475   set_control(_gvn.transform(new ProjNode(membar, TypeFunc::Control)));
3476   if (alias_idx == Compile::AliasIdxBot) {
3477     merged_memory()->set_base_memory(_gvn.transform(new ProjNode(membar, TypeFunc::Memory)));
3478   } else {
3479     set_memory(_gvn.transform(new ProjNode(membar, TypeFunc::Memory)),alias_idx);
3480   }
3481   return membar;
3482 }
3483 
3484 //------------------------------shared_lock------------------------------------
3485 // Emit locking code.
3486 FastLockNode* GraphKit::shared_lock(Node* obj) {
3487   // bci is either a monitorenter bc or InvocationEntryBci
3488   // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
3489   assert(SynchronizationEntryBCI == InvocationEntryBci, "");
3490 
3491   if (stopped())                // Dead monitor?
3492     return nullptr;
3493 
3494   assert(dead_locals_are_killed(), "should kill locals before sync. point");
3495 
3496   // Box the stack location
3497   Node* box = new BoxLockNode(next_monitor());
3498   // Check for bailout after new BoxLockNode
3499   if (failing()) { return nullptr; }
3500   box = _gvn.transform(box);
3501   Node* mem = reset_memory();
3502 
3503   FastLockNode * flock = _gvn.transform(new FastLockNode(nullptr, obj, box) )->as_FastLock();
3504 
3505   // Add monitor to debug info for the slow path.  If we block inside the
3506   // slow path and de-opt, we need the monitor hanging around
3507   map()->push_monitor( flock );
3508 
3509   const TypeFunc *tf = LockNode::lock_type();
3510   LockNode *lock = new LockNode(C, tf);
3511 
3512   lock->init_req( TypeFunc::Control, control() );
3513   lock->init_req( TypeFunc::Memory , mem );
3514   lock->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
3515   lock->init_req( TypeFunc::FramePtr, frameptr() );
3516   lock->init_req( TypeFunc::ReturnAdr, top() );
3517 
3518   lock->init_req(TypeFunc::Parms + 0, obj);
3519   lock->init_req(TypeFunc::Parms + 1, box);
3520   lock->init_req(TypeFunc::Parms + 2, flock);
3521   add_safepoint_edges(lock);
3522 
3523   lock = _gvn.transform( lock )->as_Lock();
3524 
3525   // lock has no side-effects, sets few values
3526   set_predefined_output_for_runtime_call(lock, mem, TypeRawPtr::BOTTOM);
3527 
3528   insert_mem_bar(Op_MemBarAcquireLock);
3529 
3530   // Add this to the worklist so that the lock can be eliminated
3531   record_for_igvn(lock);
3532 
3533 #ifndef PRODUCT
3534   if (PrintLockStatistics) {
3535     // Update the counter for this lock.  Don't bother using an atomic
3536     // operation since we don't require absolute accuracy.
3537     lock->create_lock_counter(map()->jvms());
3538     increment_counter(lock->counter()->addr());
3539   }
3540 #endif
3541 
3542   return flock;
3543 }
3544 
3545 
3546 //------------------------------shared_unlock----------------------------------
3547 // Emit unlocking code.
3548 void GraphKit::shared_unlock(Node* box, Node* obj) {
3549   // bci is either a monitorenter bc or InvocationEntryBci
3550   // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
3551   assert(SynchronizationEntryBCI == InvocationEntryBci, "");
3552 
3553   if (stopped()) {               // Dead monitor?
3554     map()->pop_monitor();        // Kill monitor from debug info
3555     return;
3556   }
3557 
3558   // Memory barrier to avoid floating things down past the locked region
3559   insert_mem_bar(Op_MemBarReleaseLock);
3560 
3561   const TypeFunc *tf = OptoRuntime::complete_monitor_exit_Type();
3562   UnlockNode *unlock = new UnlockNode(C, tf);
3563 #ifdef ASSERT
3564   unlock->set_dbg_jvms(sync_jvms());
3565 #endif
3566   uint raw_idx = Compile::AliasIdxRaw;
3567   unlock->init_req( TypeFunc::Control, control() );
3568   unlock->init_req( TypeFunc::Memory , memory(raw_idx) );
3569   unlock->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
3570   unlock->init_req( TypeFunc::FramePtr, frameptr() );
3571   unlock->init_req( TypeFunc::ReturnAdr, top() );
3572 
3573   unlock->init_req(TypeFunc::Parms + 0, obj);
3574   unlock->init_req(TypeFunc::Parms + 1, box);
3575   unlock = _gvn.transform(unlock)->as_Unlock();
3576 
3577   Node* mem = reset_memory();
3578 
3579   // unlock has no side-effects, sets few values
3580   set_predefined_output_for_runtime_call(unlock, mem, TypeRawPtr::BOTTOM);
3581 
3582   // Kill monitor from debug info
3583   map()->pop_monitor( );
3584 }
3585 
3586 //-------------------------------get_layout_helper-----------------------------
3587 // If the given klass is a constant or known to be an array,
3588 // fetch the constant layout helper value into constant_value
3589 // and return null.  Otherwise, load the non-constant
3590 // layout helper value, and return the node which represents it.
3591 // This two-faced routine is useful because allocation sites
3592 // almost always feature constant types.
3593 Node* GraphKit::get_layout_helper(Node* klass_node, jint& constant_value) {
3594   const TypeKlassPtr* klass_t = _gvn.type(klass_node)->isa_klassptr();
3595   if (!StressReflectiveCode && klass_t != nullptr) {
3596     bool xklass = klass_t->klass_is_exact();
3597     if (xklass || (klass_t->isa_aryklassptr() && klass_t->is_aryklassptr()->elem() != Type::BOTTOM)) {
3598       jint lhelper;
3599       if (klass_t->isa_aryklassptr()) {
3600         BasicType elem = klass_t->as_instance_type()->isa_aryptr()->elem()->array_element_basic_type();
3601         if (is_reference_type(elem, true)) {
3602           elem = T_OBJECT;
3603         }
3604         lhelper = Klass::array_layout_helper(elem);
3605       } else {
3606         lhelper = klass_t->is_instklassptr()->exact_klass()->layout_helper();
3607       }
3608       if (lhelper != Klass::_lh_neutral_value) {
3609         constant_value = lhelper;
3610         return (Node*) nullptr;
3611       }
3612     }
3613   }
3614   constant_value = Klass::_lh_neutral_value;  // put in a known value
3615   Node* lhp = basic_plus_adr(top(), klass_node, in_bytes(Klass::layout_helper_offset()));
3616   return make_load(nullptr, lhp, TypeInt::INT, T_INT, MemNode::unordered);
3617 }
3618 
3619 // We just put in an allocate/initialize with a big raw-memory effect.
3620 // Hook selected additional alias categories on the initialization.
3621 static void hook_memory_on_init(GraphKit& kit, int alias_idx,
3622                                 MergeMemNode* init_in_merge,
3623                                 Node* init_out_raw) {
3624   DEBUG_ONLY(Node* init_in_raw = init_in_merge->base_memory());
3625   assert(init_in_merge->memory_at(alias_idx) == init_in_raw, "");
3626 
3627   Node* prevmem = kit.memory(alias_idx);
3628   init_in_merge->set_memory_at(alias_idx, prevmem);
3629   kit.set_memory(init_out_raw, alias_idx);
3630 }
3631 
3632 //---------------------------set_output_for_allocation-------------------------
3633 Node* GraphKit::set_output_for_allocation(AllocateNode* alloc,
3634                                           const TypeOopPtr* oop_type,
3635                                           bool deoptimize_on_exception) {
3636   int rawidx = Compile::AliasIdxRaw;
3637   alloc->set_req( TypeFunc::FramePtr, frameptr() );
3638   add_safepoint_edges(alloc);
3639   Node* allocx = _gvn.transform(alloc);
3640   set_control( _gvn.transform(new ProjNode(allocx, TypeFunc::Control) ) );
3641   // create memory projection for i_o
3642   set_memory ( _gvn.transform( new ProjNode(allocx, TypeFunc::Memory, true) ), rawidx );
3643   make_slow_call_ex(allocx, env()->Throwable_klass(), true, deoptimize_on_exception);
3644 
3645   // create a memory projection as for the normal control path
3646   Node* malloc = _gvn.transform(new ProjNode(allocx, TypeFunc::Memory));
3647   set_memory(malloc, rawidx);
3648 
3649   // a normal slow-call doesn't change i_o, but an allocation does
3650   // we create a separate i_o projection for the normal control path
3651   set_i_o(_gvn.transform( new ProjNode(allocx, TypeFunc::I_O, false) ) );
3652   Node* rawoop = _gvn.transform( new ProjNode(allocx, TypeFunc::Parms) );
3653 
3654   // put in an initialization barrier
3655   InitializeNode* init = insert_mem_bar_volatile(Op_Initialize, rawidx,
3656                                                  rawoop)->as_Initialize();
3657   assert(alloc->initialization() == init,  "2-way macro link must work");
3658   assert(init ->allocation()     == alloc, "2-way macro link must work");
3659   {
3660     // Extract memory strands which may participate in the new object's
3661     // initialization, and source them from the new InitializeNode.
3662     // This will allow us to observe initializations when they occur,
3663     // and link them properly (as a group) to the InitializeNode.
3664     assert(init->in(InitializeNode::Memory) == malloc, "");
3665     MergeMemNode* minit_in = MergeMemNode::make(malloc);
3666     init->set_req(InitializeNode::Memory, minit_in);
3667     record_for_igvn(minit_in); // fold it up later, if possible
3668     Node* minit_out = memory(rawidx);
3669     assert(minit_out->is_Proj() && minit_out->in(0) == init, "");
3670     int mark_idx = C->get_alias_index(oop_type->add_offset(oopDesc::mark_offset_in_bytes()));
3671     // Add an edge in the MergeMem for the header fields so an access to one of those has correct memory state.
3672     // Use one NarrowMemProjNode per slice to properly record the adr type of each slice. The Initialize node will have
3673     // multiple projections as a result.
3674     set_memory(_gvn.transform(new NarrowMemProjNode(init, C->get_adr_type(mark_idx))), mark_idx);
3675     int klass_idx = C->get_alias_index(oop_type->add_offset(oopDesc::klass_offset_in_bytes()));
3676     set_memory(_gvn.transform(new NarrowMemProjNode(init, C->get_adr_type(klass_idx))), klass_idx);
3677     if (oop_type->isa_aryptr()) {
3678       const TypePtr* telemref = oop_type->add_offset(Type::OffsetBot);
3679       int            elemidx  = C->get_alias_index(telemref);
3680       hook_memory_on_init(*this, elemidx, minit_in, _gvn.transform(new NarrowMemProjNode(init, C->get_adr_type(elemidx))));
3681     } else if (oop_type->isa_instptr()) {
3682       ciInstanceKlass* ik = oop_type->is_instptr()->instance_klass();
3683       for (int i = 0, len = ik->nof_nonstatic_fields(); i < len; i++) {
3684         ciField* field = ik->nonstatic_field_at(i);
3685         if (field->offset_in_bytes() >= TrackedInitializationLimit * HeapWordSize)
3686           continue;  // do not bother to track really large numbers of fields
3687         // Find (or create) the alias category for this field:
3688         int fieldidx = C->alias_type(field)->index();
3689         hook_memory_on_init(*this, fieldidx, minit_in, _gvn.transform(new NarrowMemProjNode(init, C->get_adr_type(fieldidx))));
3690       }
3691     }
3692   }
3693 
3694   // Cast raw oop to the real thing...
3695   Node* javaoop = new CheckCastPPNode(control(), rawoop, oop_type);
3696   javaoop = _gvn.transform(javaoop);
3697   C->set_recent_alloc(control(), javaoop);
3698   assert(just_allocated_object(control()) == javaoop, "just allocated");
3699 
3700 #ifdef ASSERT
3701   { // Verify that the AllocateNode::Ideal_allocation recognizers work:
3702     assert(AllocateNode::Ideal_allocation(rawoop) == alloc,
3703            "Ideal_allocation works");
3704     assert(AllocateNode::Ideal_allocation(javaoop) == alloc,
3705            "Ideal_allocation works");
3706     if (alloc->is_AllocateArray()) {
3707       assert(AllocateArrayNode::Ideal_array_allocation(rawoop) == alloc->as_AllocateArray(),
3708              "Ideal_allocation works");
3709       assert(AllocateArrayNode::Ideal_array_allocation(javaoop) == alloc->as_AllocateArray(),
3710              "Ideal_allocation works");
3711     } else {
3712       assert(alloc->in(AllocateNode::ALength)->is_top(), "no length, please");
3713     }
3714   }
3715 #endif //ASSERT
3716 
3717   return javaoop;
3718 }
3719 
3720 //---------------------------new_instance--------------------------------------
3721 // This routine takes a klass_node which may be constant (for a static type)
3722 // or may be non-constant (for reflective code).  It will work equally well
3723 // for either, and the graph will fold nicely if the optimizer later reduces
3724 // the type to a constant.
3725 // The optional arguments are for specialized use by intrinsics:
3726 //  - If 'extra_slow_test' if not null is an extra condition for the slow-path.
3727 //  - If 'return_size_val', report the total object size to the caller.
3728 //  - deoptimize_on_exception controls how Java exceptions are handled (rethrow vs deoptimize)
3729 Node* GraphKit::new_instance(Node* klass_node,
3730                              Node* extra_slow_test,
3731                              Node* *return_size_val,
3732                              bool deoptimize_on_exception) {
3733   // Compute size in doublewords
3734   // The size is always an integral number of doublewords, represented
3735   // as a positive bytewise size stored in the klass's layout_helper.
3736   // The layout_helper also encodes (in a low bit) the need for a slow path.
3737   jint  layout_con = Klass::_lh_neutral_value;
3738   Node* layout_val = get_layout_helper(klass_node, layout_con);
3739   int   layout_is_con = (layout_val == nullptr);
3740 
3741   if (extra_slow_test == nullptr)  extra_slow_test = intcon(0);
3742   // Generate the initial go-slow test.  It's either ALWAYS (return a
3743   // Node for 1) or NEVER (return a null) or perhaps (in the reflective
3744   // case) a computed value derived from the layout_helper.
3745   Node* initial_slow_test = nullptr;
3746   if (layout_is_con) {
3747     assert(!StressReflectiveCode, "stress mode does not use these paths");
3748     bool must_go_slow = Klass::layout_helper_needs_slow_path(layout_con);
3749     initial_slow_test = must_go_slow ? intcon(1) : extra_slow_test;
3750   } else {   // reflective case
3751     // This reflective path is used by Unsafe.allocateInstance.
3752     // (It may be stress-tested by specifying StressReflectiveCode.)
3753     // Basically, we want to get into the VM is there's an illegal argument.
3754     Node* bit = intcon(Klass::_lh_instance_slow_path_bit);
3755     initial_slow_test = _gvn.transform( new AndINode(layout_val, bit) );
3756     if (extra_slow_test != intcon(0)) {
3757       initial_slow_test = _gvn.transform( new OrINode(initial_slow_test, extra_slow_test) );
3758     }
3759     // (Macro-expander will further convert this to a Bool, if necessary.)
3760   }
3761 
3762   // Find the size in bytes.  This is easy; it's the layout_helper.
3763   // The size value must be valid even if the slow path is taken.
3764   Node* size = nullptr;
3765   if (layout_is_con) {
3766     size = MakeConX(Klass::layout_helper_size_in_bytes(layout_con));
3767   } else {   // reflective case
3768     // This reflective path is used by clone and Unsafe.allocateInstance.
3769     size = ConvI2X(layout_val);
3770 
3771     // Clear the low bits to extract layout_helper_size_in_bytes:
3772     assert((int)Klass::_lh_instance_slow_path_bit < BytesPerLong, "clear bit");
3773     Node* mask = MakeConX(~ (intptr_t)right_n_bits(LogBytesPerLong));
3774     size = _gvn.transform( new AndXNode(size, mask) );
3775   }
3776   if (return_size_val != nullptr) {
3777     (*return_size_val) = size;
3778   }
3779 
3780   // This is a precise notnull oop of the klass.
3781   // (Actually, it need not be precise if this is a reflective allocation.)
3782   // It's what we cast the result to.
3783   const TypeKlassPtr* tklass = _gvn.type(klass_node)->isa_klassptr();
3784   if (!tklass)  tklass = TypeInstKlassPtr::OBJECT;
3785   const TypeOopPtr* oop_type = tklass->as_instance_type();
3786 
3787   // Now generate allocation code
3788 
3789   // The entire memory state is needed for slow path of the allocation
3790   // since GC and deoptimization can happened.
3791   Node *mem = reset_memory();
3792   set_all_memory(mem); // Create new memory state
3793 
3794   AllocateNode* alloc = new AllocateNode(C, AllocateNode::alloc_type(Type::TOP),
3795                                          control(), mem, i_o(),
3796                                          size, klass_node,
3797                                          initial_slow_test);
3798 
3799   return set_output_for_allocation(alloc, oop_type, deoptimize_on_exception);
3800 }
3801 
3802 //-------------------------------new_array-------------------------------------
3803 // helper for both newarray and anewarray
3804 // The 'length' parameter is (obviously) the length of the array.
3805 // The optional arguments are for specialized use by intrinsics:
3806 //  - If 'return_size_val', report the non-padded array size (sum of header size
3807 //    and array body) to the caller.
3808 //  - deoptimize_on_exception controls how Java exceptions are handled (rethrow vs deoptimize)
3809 Node* GraphKit::new_array(Node* klass_node,     // array klass (maybe variable)
3810                           Node* length,         // number of array elements
3811                           int   nargs,          // number of arguments to push back for uncommon trap
3812                           Node* *return_size_val,
3813                           bool deoptimize_on_exception) {
3814   jint  layout_con = Klass::_lh_neutral_value;
3815   Node* layout_val = get_layout_helper(klass_node, layout_con);
3816   int   layout_is_con = (layout_val == nullptr);
3817 
3818   if (!layout_is_con && !StressReflectiveCode &&
3819       !too_many_traps(Deoptimization::Reason_class_check)) {
3820     // This is a reflective array creation site.
3821     // Optimistically assume that it is a subtype of Object[],
3822     // so that we can fold up all the address arithmetic.
3823     layout_con = Klass::array_layout_helper(T_OBJECT);
3824     Node* cmp_lh = _gvn.transform( new CmpINode(layout_val, intcon(layout_con)) );
3825     Node* bol_lh = _gvn.transform( new BoolNode(cmp_lh, BoolTest::eq) );
3826     { BuildCutout unless(this, bol_lh, PROB_MAX);
3827       inc_sp(nargs);
3828       uncommon_trap(Deoptimization::Reason_class_check,
3829                     Deoptimization::Action_maybe_recompile);
3830     }
3831     layout_val = nullptr;
3832     layout_is_con = true;
3833   }
3834 
3835   // Generate the initial go-slow test.  Make sure we do not overflow
3836   // if length is huge (near 2Gig) or negative!  We do not need
3837   // exact double-words here, just a close approximation of needed
3838   // double-words.  We can't add any offset or rounding bits, lest we
3839   // take a size -1 of bytes and make it positive.  Use an unsigned
3840   // compare, so negative sizes look hugely positive.
3841   int fast_size_limit = FastAllocateSizeLimit;
3842   if (layout_is_con) {
3843     assert(!StressReflectiveCode, "stress mode does not use these paths");
3844     // Increase the size limit if we have exact knowledge of array type.
3845     int log2_esize = Klass::layout_helper_log2_element_size(layout_con);
3846     assert(fast_size_limit == 0 || count_leading_zeros(fast_size_limit) > static_cast<unsigned>(LogBytesPerLong - log2_esize),
3847            "fast_size_limit (%d) overflow when shifted left by %d", fast_size_limit, LogBytesPerLong - log2_esize);
3848     fast_size_limit <<= (LogBytesPerLong - log2_esize);
3849   }
3850 
3851   Node* initial_slow_cmp  = _gvn.transform( new CmpUNode( length, intcon( fast_size_limit ) ) );
3852   Node* initial_slow_test = _gvn.transform( new BoolNode( initial_slow_cmp, BoolTest::gt ) );
3853 
3854   // --- Size Computation ---
3855   // array_size = round_to_heap(array_header + (length << elem_shift));
3856   // where round_to_heap(x) == align_to(x, MinObjAlignmentInBytes)
3857   // and align_to(x, y) == ((x + y-1) & ~(y-1))
3858   // The rounding mask is strength-reduced, if possible.
3859   int round_mask = MinObjAlignmentInBytes - 1;
3860   Node* header_size = nullptr;
3861   // (T_BYTE has the weakest alignment and size restrictions...)
3862   if (layout_is_con) {
3863     int       hsize  = Klass::layout_helper_header_size(layout_con);
3864     int       eshift = Klass::layout_helper_log2_element_size(layout_con);
3865     if ((round_mask & ~right_n_bits(eshift)) == 0)
3866       round_mask = 0;  // strength-reduce it if it goes away completely
3867     assert((hsize & right_n_bits(eshift)) == 0, "hsize is pre-rounded");
3868     int header_size_min = arrayOopDesc::base_offset_in_bytes(T_BYTE);
3869     assert(header_size_min <= hsize, "generic minimum is smallest");
3870     header_size = intcon(hsize);
3871   } else {
3872     Node* hss   = intcon(Klass::_lh_header_size_shift);
3873     Node* hsm   = intcon(Klass::_lh_header_size_mask);
3874     header_size = _gvn.transform(new URShiftINode(layout_val, hss));
3875     header_size = _gvn.transform(new AndINode(header_size, hsm));
3876   }
3877 
3878   Node* elem_shift = nullptr;
3879   if (layout_is_con) {
3880     int eshift = Klass::layout_helper_log2_element_size(layout_con);
3881     if (eshift != 0)
3882       elem_shift = intcon(eshift);
3883   } else {
3884     // There is no need to mask or shift this value.
3885     // The semantics of LShiftINode include an implicit mask to 0x1F.
3886     assert(Klass::_lh_log2_element_size_shift == 0, "use shift in place");
3887     elem_shift = layout_val;
3888   }
3889 
3890   // Transition to native address size for all offset calculations:
3891   Node* lengthx = ConvI2X(length);
3892   Node* headerx = ConvI2X(header_size);
3893 #ifdef _LP64
3894   { const TypeInt* tilen = _gvn.find_int_type(length);
3895     if (tilen != nullptr && tilen->_lo < 0) {
3896       // Add a manual constraint to a positive range.  Cf. array_element_address.
3897       jint size_max = fast_size_limit;
3898       if (size_max > tilen->_hi && tilen->_hi >= 0) {
3899         size_max = tilen->_hi;
3900       }
3901       const TypeInt* tlcon = TypeInt::make(0, size_max, Type::WidenMin);
3902 
3903       // Only do a narrow I2L conversion if the range check passed.
3904       IfNode* iff = new IfNode(control(), initial_slow_test, PROB_MIN, COUNT_UNKNOWN);
3905       _gvn.transform(iff);
3906       RegionNode* region = new RegionNode(3);
3907       _gvn.set_type(region, Type::CONTROL);
3908       lengthx = new PhiNode(region, TypeLong::LONG);
3909       _gvn.set_type(lengthx, TypeLong::LONG);
3910 
3911       // Range check passed. Use ConvI2L node with narrow type.
3912       Node* passed = IfFalse(iff);
3913       region->init_req(1, passed);
3914       // Make I2L conversion control dependent to prevent it from
3915       // floating above the range check during loop optimizations.
3916       lengthx->init_req(1, C->constrained_convI2L(&_gvn, length, tlcon, passed));
3917 
3918       // Range check failed. Use ConvI2L with wide type because length may be invalid.
3919       region->init_req(2, IfTrue(iff));
3920       lengthx->init_req(2, ConvI2X(length));
3921 
3922       set_control(region);
3923       record_for_igvn(region);
3924       record_for_igvn(lengthx);
3925     }
3926   }
3927 #endif
3928 
3929   // Combine header size and body size for the array copy part, then align (if
3930   // necessary) for the allocation part. This computation cannot overflow,
3931   // because it is used only in two places, one where the length is sharply
3932   // limited, and the other after a successful allocation.
3933   Node* abody = lengthx;
3934   if (elem_shift != nullptr) {
3935     abody = _gvn.transform(new LShiftXNode(lengthx, elem_shift));
3936   }
3937   Node* non_rounded_size = _gvn.transform(new AddXNode(headerx, abody));
3938 
3939   if (return_size_val != nullptr) {
3940     // This is the size
3941     (*return_size_val) = non_rounded_size;
3942   }
3943 
3944   Node* size = non_rounded_size;
3945   if (round_mask != 0) {
3946     Node* mask1 = MakeConX(round_mask);
3947     size = _gvn.transform(new AddXNode(size, mask1));
3948     Node* mask2 = MakeConX(~round_mask);
3949     size = _gvn.transform(new AndXNode(size, mask2));
3950   }
3951   // else if round_mask == 0, the size computation is self-rounding
3952 
3953   // Now generate allocation code
3954 
3955   // The entire memory state is needed for slow path of the allocation
3956   // since GC and deoptimization can happened.
3957   Node *mem = reset_memory();
3958   set_all_memory(mem); // Create new memory state
3959 
3960   if (initial_slow_test->is_Bool()) {
3961     // Hide it behind a CMoveI, or else PhaseIdealLoop::split_up will get sick.
3962     initial_slow_test = initial_slow_test->as_Bool()->as_int_value(&_gvn);
3963   }
3964 
3965   const TypeOopPtr* ary_type = _gvn.type(klass_node)->is_klassptr()->as_instance_type();
3966   Node* valid_length_test = _gvn.intcon(1);
3967   if (ary_type->isa_aryptr()) {
3968     BasicType bt = ary_type->isa_aryptr()->elem()->array_element_basic_type();
3969     jint max = TypeAryPtr::max_array_length(bt);
3970     Node* valid_length_cmp  = _gvn.transform(new CmpUNode(length, intcon(max)));
3971     valid_length_test = _gvn.transform(new BoolNode(valid_length_cmp, BoolTest::le));
3972   }
3973 
3974   // Create the AllocateArrayNode and its result projections
3975   AllocateArrayNode* alloc
3976     = new AllocateArrayNode(C, AllocateArrayNode::alloc_type(TypeInt::INT),
3977                             control(), mem, i_o(),
3978                             size, klass_node,
3979                             initial_slow_test,
3980                             length, valid_length_test);
3981 
3982   // Cast to correct type.  Note that the klass_node may be constant or not,
3983   // and in the latter case the actual array type will be inexact also.
3984   // (This happens via a non-constant argument to inline_native_newArray.)
3985   // In any case, the value of klass_node provides the desired array type.
3986   const TypeInt* length_type = _gvn.find_int_type(length);
3987   if (ary_type->isa_aryptr() && length_type != nullptr) {
3988     // Try to get a better type than POS for the size
3989     ary_type = ary_type->is_aryptr()->cast_to_size(length_type);
3990   }
3991 
3992   Node* javaoop = set_output_for_allocation(alloc, ary_type, deoptimize_on_exception);
3993 
3994   array_ideal_length(alloc, ary_type, true);
3995   return javaoop;
3996 }
3997 
3998 // The following "Ideal_foo" functions are placed here because they recognize
3999 // the graph shapes created by the functions immediately above.
4000 
4001 //---------------------------Ideal_allocation----------------------------------
4002 // Given an oop pointer or raw pointer, see if it feeds from an AllocateNode.
4003 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr) {
4004   if (ptr == nullptr) {     // reduce dumb test in callers
4005     return nullptr;
4006   }
4007 
4008   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
4009   ptr = bs->step_over_gc_barrier(ptr);
4010 
4011   if (ptr->is_CheckCastPP()) { // strip only one raw-to-oop cast
4012     ptr = ptr->in(1);
4013     if (ptr == nullptr) return nullptr;
4014   }
4015   // Return null for allocations with several casts:
4016   //   j.l.reflect.Array.newInstance(jobject, jint)
4017   //   Object.clone()
4018   // to keep more precise type from last cast.
4019   if (ptr->is_Proj()) {
4020     Node* allo = ptr->in(0);
4021     if (allo != nullptr && allo->is_Allocate()) {
4022       return allo->as_Allocate();
4023     }
4024   }
4025   // Report failure to match.
4026   return nullptr;
4027 }
4028 
4029 // Fancy version which also strips off an offset (and reports it to caller).
4030 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseValues* phase,
4031                                              intptr_t& offset) {
4032   Node* base = AddPNode::Ideal_base_and_offset(ptr, phase, offset);
4033   if (base == nullptr)  return nullptr;
4034   return Ideal_allocation(base);
4035 }
4036 
4037 // Trace Initialize <- Proj[Parm] <- Allocate
4038 AllocateNode* InitializeNode::allocation() {
4039   Node* rawoop = in(InitializeNode::RawAddress);
4040   if (rawoop->is_Proj()) {
4041     Node* alloc = rawoop->in(0);
4042     if (alloc->is_Allocate()) {
4043       return alloc->as_Allocate();
4044     }
4045   }
4046   return nullptr;
4047 }
4048 
4049 // Trace Allocate -> Proj[Parm] -> Initialize
4050 InitializeNode* AllocateNode::initialization() {
4051   ProjNode* rawoop = proj_out_or_null(AllocateNode::RawAddress);
4052   if (rawoop == nullptr)  return nullptr;
4053   for (DUIterator_Fast imax, i = rawoop->fast_outs(imax); i < imax; i++) {
4054     Node* init = rawoop->fast_out(i);
4055     if (init->is_Initialize()) {
4056       assert(init->as_Initialize()->allocation() == this, "2-way link");
4057       return init->as_Initialize();
4058     }
4059   }
4060   return nullptr;
4061 }
4062 
4063 // Add a Parse Predicate with an uncommon trap on the failing/false path. Normal control will continue on the true path.
4064 void GraphKit::add_parse_predicate(Deoptimization::DeoptReason reason, const int nargs) {
4065   // Too many traps seen?
4066   if (too_many_traps(reason)) {
4067 #ifdef ASSERT
4068     if (TraceLoopPredicate) {
4069       int tc = C->trap_count(reason);
4070       tty->print("too many traps=%s tcount=%d in ",
4071                     Deoptimization::trap_reason_name(reason), tc);
4072       method()->print(); // which method has too many predicate traps
4073       tty->cr();
4074     }
4075 #endif
4076     // We cannot afford to take more traps here,
4077     // do not generate Parse Predicate.
4078     return;
4079   }
4080 
4081   ParsePredicateNode* parse_predicate = new ParsePredicateNode(control(), reason, &_gvn);
4082   _gvn.set_type(parse_predicate, parse_predicate->Value(&_gvn));
4083   Node* if_false = _gvn.transform(new IfFalseNode(parse_predicate));
4084   {
4085     PreserveJVMState pjvms(this);
4086     set_control(if_false);
4087     inc_sp(nargs);
4088     uncommon_trap(reason, Deoptimization::Action_maybe_recompile);
4089   }
4090   Node* if_true = _gvn.transform(new IfTrueNode(parse_predicate));
4091   set_control(if_true);
4092 }
4093 
4094 // Add Parse Predicates which serve as placeholders to create new Runtime Predicates above them. All
4095 // Runtime Predicates inside a Runtime Predicate block share the same uncommon trap as the Parse Predicate.
4096 void GraphKit::add_parse_predicates(int nargs) {
4097   if (ShortRunningLongLoop) {
4098     // Will narrow the limit down with a cast node. Predicates added later may depend on the cast so should be last when
4099     // walking up from the loop.
4100     add_parse_predicate(Deoptimization::Reason_short_running_long_loop, nargs);
4101   }
4102   if (UseLoopPredicate) {
4103     add_parse_predicate(Deoptimization::Reason_predicate, nargs);
4104     if (UseProfiledLoopPredicate) {
4105       add_parse_predicate(Deoptimization::Reason_profile_predicate, nargs);
4106     }
4107   }
4108   if (UseAutoVectorizationPredicate) {
4109     add_parse_predicate(Deoptimization::Reason_auto_vectorization_check, nargs);
4110   }
4111   // Loop Limit Check Predicate should be near the loop.
4112   add_parse_predicate(Deoptimization::Reason_loop_limit_check, nargs);
4113 }
4114 
4115 void GraphKit::sync_kit(IdealKit& ideal) {
4116   set_all_memory(ideal.merged_memory());
4117   set_i_o(ideal.i_o());
4118   set_control(ideal.ctrl());
4119 }
4120 
4121 void GraphKit::final_sync(IdealKit& ideal) {
4122   // Final sync IdealKit and graphKit.
4123   sync_kit(ideal);
4124 }
4125 
4126 Node* GraphKit::load_String_length(Node* str, bool set_ctrl) {
4127   Node* len = load_array_length(load_String_value(str, set_ctrl));
4128   Node* coder = load_String_coder(str, set_ctrl);
4129   // Divide length by 2 if coder is UTF16
4130   return _gvn.transform(new RShiftINode(len, coder));
4131 }
4132 
4133 Node* GraphKit::load_String_value(Node* str, bool set_ctrl) {
4134   int value_offset = java_lang_String::value_offset();
4135   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4136                                                      false, nullptr, 0);
4137   const TypePtr* value_field_type = string_type->add_offset(value_offset);
4138   const TypeAryPtr* value_type = TypeAryPtr::make(TypePtr::NotNull,
4139                                                   TypeAry::make(TypeInt::BYTE, TypeInt::POS),
4140                                                   ciTypeArrayKlass::make(T_BYTE), true, 0);
4141   Node* p = basic_plus_adr(str, str, value_offset);
4142   Node* load = access_load_at(str, p, value_field_type, value_type, T_OBJECT,
4143                               IN_HEAP | (set_ctrl ? C2_CONTROL_DEPENDENT_LOAD : 0) | MO_UNORDERED);
4144   return load;
4145 }
4146 
4147 Node* GraphKit::load_String_coder(Node* str, bool set_ctrl) {
4148   if (!CompactStrings) {
4149     return intcon(java_lang_String::CODER_UTF16);
4150   }
4151   int coder_offset = java_lang_String::coder_offset();
4152   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4153                                                      false, nullptr, 0);
4154   const TypePtr* coder_field_type = string_type->add_offset(coder_offset);
4155 
4156   Node* p = basic_plus_adr(str, str, coder_offset);
4157   Node* load = access_load_at(str, p, coder_field_type, TypeInt::BYTE, T_BYTE,
4158                               IN_HEAP | (set_ctrl ? C2_CONTROL_DEPENDENT_LOAD : 0) | MO_UNORDERED);
4159   return load;
4160 }
4161 
4162 void GraphKit::store_String_value(Node* str, Node* value) {
4163   int value_offset = java_lang_String::value_offset();
4164   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4165                                                      false, nullptr, 0);
4166   const TypePtr* value_field_type = string_type->add_offset(value_offset);
4167 
4168   access_store_at(str,  basic_plus_adr(str, value_offset), value_field_type,
4169                   value, TypeAryPtr::BYTES, T_OBJECT, IN_HEAP | MO_UNORDERED);
4170 }
4171 
4172 void GraphKit::store_String_coder(Node* str, Node* value) {
4173   int coder_offset = java_lang_String::coder_offset();
4174   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4175                                                      false, nullptr, 0);
4176   const TypePtr* coder_field_type = string_type->add_offset(coder_offset);
4177 
4178   access_store_at(str, basic_plus_adr(str, coder_offset), coder_field_type,
4179                   value, TypeInt::BYTE, T_BYTE, IN_HEAP | MO_UNORDERED);
4180 }
4181 
4182 // Capture src and dst memory state with a MergeMemNode
4183 Node* GraphKit::capture_memory(const TypePtr* src_type, const TypePtr* dst_type) {
4184   if (src_type == dst_type) {
4185     // Types are equal, we don't need a MergeMemNode
4186     return memory(src_type);
4187   }
4188   MergeMemNode* merge = MergeMemNode::make(map()->memory());
4189   record_for_igvn(merge); // fold it up later, if possible
4190   int src_idx = C->get_alias_index(src_type);
4191   int dst_idx = C->get_alias_index(dst_type);
4192   merge->set_memory_at(src_idx, memory(src_idx));
4193   merge->set_memory_at(dst_idx, memory(dst_idx));
4194   return merge;
4195 }
4196 
4197 Node* GraphKit::compress_string(Node* src, const TypeAryPtr* src_type, Node* dst, Node* count) {
4198   assert(Matcher::match_rule_supported(Op_StrCompressedCopy), "Intrinsic not supported");
4199   assert(src_type == TypeAryPtr::BYTES || src_type == TypeAryPtr::CHARS, "invalid source type");
4200   // If input and output memory types differ, capture both states to preserve
4201   // the dependency between preceding and subsequent loads/stores.
4202   // For example, the following program:
4203   //  StoreB
4204   //  compress_string
4205   //  LoadB
4206   // has this memory graph (use->def):
4207   //  LoadB -> compress_string -> CharMem
4208   //             ... -> StoreB -> ByteMem
4209   // The intrinsic hides the dependency between LoadB and StoreB, causing
4210   // the load to read from memory not containing the result of the StoreB.
4211   // The correct memory graph should look like this:
4212   //  LoadB -> compress_string -> MergeMem(CharMem, StoreB(ByteMem))
4213   Node* mem = capture_memory(src_type, TypeAryPtr::BYTES);
4214   StrCompressedCopyNode* str = new StrCompressedCopyNode(control(), mem, src, dst, count);
4215   Node* res_mem = _gvn.transform(new SCMemProjNode(_gvn.transform(str)));
4216   set_memory(res_mem, TypeAryPtr::BYTES);
4217   return str;
4218 }
4219 
4220 void GraphKit::inflate_string(Node* src, Node* dst, const TypeAryPtr* dst_type, Node* count) {
4221   assert(Matcher::match_rule_supported(Op_StrInflatedCopy), "Intrinsic not supported");
4222   assert(dst_type == TypeAryPtr::BYTES || dst_type == TypeAryPtr::CHARS, "invalid dest type");
4223   // Capture src and dst memory (see comment in 'compress_string').
4224   Node* mem = capture_memory(TypeAryPtr::BYTES, dst_type);
4225   StrInflatedCopyNode* str = new StrInflatedCopyNode(control(), mem, src, dst, count);
4226   set_memory(_gvn.transform(str), dst_type);
4227 }
4228 
4229 void GraphKit::inflate_string_slow(Node* src, Node* dst, Node* start, Node* count) {
4230   /**
4231    * int i_char = start;
4232    * for (int i_byte = 0; i_byte < count; i_byte++) {
4233    *   dst[i_char++] = (char)(src[i_byte] & 0xff);
4234    * }
4235    */
4236   add_parse_predicates();
4237   C->set_has_loops(true);
4238 
4239   RegionNode* head = new RegionNode(3);
4240   head->init_req(1, control());
4241   gvn().set_type(head, Type::CONTROL);
4242   record_for_igvn(head);
4243 
4244   Node* i_byte = new PhiNode(head, TypeInt::INT);
4245   i_byte->init_req(1, intcon(0));
4246   gvn().set_type(i_byte, TypeInt::INT);
4247   record_for_igvn(i_byte);
4248 
4249   Node* i_char = new PhiNode(head, TypeInt::INT);
4250   i_char->init_req(1, start);
4251   gvn().set_type(i_char, TypeInt::INT);
4252   record_for_igvn(i_char);
4253 
4254   Node* mem = PhiNode::make(head, memory(TypeAryPtr::BYTES), Type::MEMORY, TypeAryPtr::BYTES);
4255   gvn().set_type(mem, Type::MEMORY);
4256   record_for_igvn(mem);
4257   set_control(head);
4258   set_memory(mem, TypeAryPtr::BYTES);
4259   Node* ch = load_array_element(src, i_byte, TypeAryPtr::BYTES, /* set_ctrl */ true);
4260   Node* st = store_to_memory(control(), array_element_address(dst, i_char, T_BYTE),
4261                              AndI(ch, intcon(0xff)), T_CHAR, MemNode::unordered, false,
4262                              false, true /* mismatched */);
4263 
4264   IfNode* iff = create_and_map_if(head, Bool(CmpI(i_byte, count), BoolTest::lt), PROB_FAIR, COUNT_UNKNOWN);
4265   head->init_req(2, IfTrue(iff));
4266   mem->init_req(2, st);
4267   i_byte->init_req(2, AddI(i_byte, intcon(1)));
4268   i_char->init_req(2, AddI(i_char, intcon(2)));
4269 
4270   set_control(IfFalse(iff));
4271   set_memory(st, TypeAryPtr::BYTES);
4272 }
4273 
4274 Node* GraphKit::make_constant_from_field(ciField* field, Node* obj) {
4275   if (!field->is_constant()) {
4276     return nullptr; // Field not marked as constant.
4277   }
4278   ciInstance* holder = nullptr;
4279   if (!field->is_static()) {
4280     ciObject* const_oop = obj->bottom_type()->is_oopptr()->const_oop();
4281     if (const_oop != nullptr && const_oop->is_instance()) {
4282       holder = const_oop->as_instance();
4283     }
4284   }
4285   const Type* con_type = Type::make_constant_from_field(field, holder, field->layout_type(),
4286                                                         /*is_unsigned_load=*/false);
4287   if (con_type != nullptr) {
4288     return makecon(con_type);
4289   }
4290   return nullptr;
4291 }
4292 
4293 Node* GraphKit::maybe_narrow_object_type(Node* obj, ciKlass* type) {
4294   const TypeOopPtr* obj_type = obj->bottom_type()->isa_oopptr();
4295   const TypeOopPtr* sig_type = TypeOopPtr::make_from_klass(type);
4296   if (obj_type != nullptr && sig_type->is_loaded() && !obj_type->higher_equal(sig_type)) {
4297     const Type* narrow_obj_type = obj_type->filter_speculative(sig_type); // keep speculative part
4298     Node* casted_obj = gvn().transform(new CheckCastPPNode(control(), obj, narrow_obj_type));
4299     return casted_obj;
4300   }
4301   return obj;
4302 }