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/memnode.hpp"
  43 #include "opto/opaquenode.hpp"
  44 #include "opto/opcodes.hpp"
  45 #include "opto/parse.hpp"
  46 #include "opto/reachability.hpp"
  47 #include "opto/rootnode.hpp"
  48 #include "opto/runtime.hpp"
  49 #include "opto/subtypenode.hpp"
  50 #include "opto/type.hpp"
  51 #include "runtime/deoptimization.hpp"
  52 #include "runtime/sharedRuntime.hpp"
  53 #include "utilities/bitMap.inline.hpp"
  54 #include "utilities/growableArray.hpp"
  55 #include "utilities/powerOfTwo.hpp"
  56 
  57 //----------------------------GraphKit-----------------------------------------
  58 // Main utility constructor.
  59 GraphKit::GraphKit(JVMState* jvms)
  60   : Phase(Phase::Parser),
  61     _env(C->env()),
  62     _gvn(*C->initial_gvn()),
  63     _barrier_set(BarrierSet::barrier_set()->barrier_set_c2())
  64 {
  65   _exceptions = jvms->map()->next_exception();
  66   if (_exceptions != nullptr)  jvms->map()->set_next_exception(nullptr);
  67   set_jvms(jvms);
  68 }
  69 
  70 // Private constructor for parser.
  71 GraphKit::GraphKit()
  72   : Phase(Phase::Parser),
  73     _env(C->env()),
  74     _gvn(*C->initial_gvn()),
  75     _barrier_set(BarrierSet::barrier_set()->barrier_set_c2())
  76 {
  77   _exceptions = nullptr;
  78   set_map(nullptr);
  79   DEBUG_ONLY(_sp = -99);
  80   DEBUG_ONLY(set_bci(-99));
  81 }
  82 
  83 
  84 
  85 //---------------------------clean_stack---------------------------------------
  86 // Clear away rubbish from the stack area of the JVM state.
  87 // This destroys any arguments that may be waiting on the stack.
  88 void GraphKit::clean_stack(int from_sp) {
  89   SafePointNode* map      = this->map();
  90   JVMState*      jvms     = this->jvms();
  91   int            stk_size = jvms->stk_size();
  92   int            stkoff   = jvms->stkoff();
  93   Node*          top      = this->top();
  94   for (int i = from_sp; i < stk_size; i++) {
  95     if (map->in(stkoff + i) != top) {
  96       map->set_req(stkoff + i, top);
  97     }
  98   }
  99 }
 100 
 101 
 102 //--------------------------------sync_jvms-----------------------------------
 103 // Make sure our current jvms agrees with our parse state.
 104 JVMState* GraphKit::sync_jvms() const {
 105   JVMState* jvms = this->jvms();
 106   jvms->set_bci(bci());       // Record the new bci in the JVMState
 107   jvms->set_sp(sp());         // Record the new sp in the JVMState
 108   assert(jvms_in_sync(), "jvms is now in sync");
 109   return jvms;
 110 }
 111 
 112 //--------------------------------sync_jvms_for_reexecute---------------------
 113 // Make sure our current jvms agrees with our parse state.  This version
 114 // uses the reexecute_sp for reexecuting bytecodes.
 115 JVMState* GraphKit::sync_jvms_for_reexecute() {
 116   JVMState* jvms = this->jvms();
 117   jvms->set_bci(bci());          // Record the new bci in the JVMState
 118   jvms->set_sp(reexecute_sp());  // Record the new sp in the JVMState
 119   return jvms;
 120 }
 121 
 122 #ifdef ASSERT
 123 bool GraphKit::jvms_in_sync() const {
 124   Parse* parse = is_Parse();
 125   if (parse == nullptr) {
 126     if (bci() !=      jvms()->bci())          return false;
 127     if (sp()  != (int)jvms()->sp())           return false;
 128     return true;
 129   }
 130   if (jvms()->method() != parse->method())    return false;
 131   if (jvms()->bci()    != parse->bci())       return false;
 132   int jvms_sp = jvms()->sp();
 133   if (jvms_sp          != parse->sp())        return false;
 134   int jvms_depth = jvms()->depth();
 135   if (jvms_depth       != parse->depth())     return false;
 136   return true;
 137 }
 138 
 139 // Local helper checks for special internal merge points
 140 // used to accumulate and merge exception states.
 141 // They are marked by the region's in(0) edge being the map itself.
 142 // Such merge points must never "escape" into the parser at large,
 143 // until they have been handed to gvn.transform.
 144 static bool is_hidden_merge(Node* reg) {
 145   if (reg == nullptr)  return false;
 146   if (reg->is_Phi()) {
 147     reg = reg->in(0);
 148     if (reg == nullptr)  return false;
 149   }
 150   return reg->is_Region() && reg->in(0) != nullptr && reg->in(0)->is_Root();
 151 }
 152 
 153 void GraphKit::verify_map() const {
 154   if (map() == nullptr)  return;  // null map is OK
 155   assert(map()->req() <= jvms()->endoff(), "no extra garbage on map");
 156   assert(!map()->has_exceptions(),    "call add_exception_states_from 1st");
 157   assert(!is_hidden_merge(control()), "call use_exception_state, not set_map");
 158 }
 159 
 160 void GraphKit::verify_exception_state(SafePointNode* ex_map) {
 161   assert(ex_map->next_exception() == nullptr, "not already part of a chain");
 162   assert(has_saved_ex_oop(ex_map), "every exception state has an ex_oop");
 163 }
 164 #endif
 165 
 166 //---------------------------stop_and_kill_map---------------------------------
 167 // Set _map to null, signalling a stop to further bytecode execution.
 168 // First smash the current map's control to a constant, to mark it dead.
 169 void GraphKit::stop_and_kill_map() {
 170   SafePointNode* dead_map = stop();
 171   if (dead_map != nullptr) {
 172     dead_map->disconnect_inputs(C); // Mark the map as killed.
 173     assert(dead_map->is_killed(), "must be so marked");
 174   }
 175 }
 176 
 177 
 178 //--------------------------------stopped--------------------------------------
 179 // Tell if _map is null, or control is top.
 180 bool GraphKit::stopped() {
 181   if (map() == nullptr)        return true;
 182   else if (control() == top()) return true;
 183   else                         return false;
 184 }
 185 
 186 
 187 //-----------------------------has_exception_handler----------------------------------
 188 // Tell if this method or any caller method has exception handlers.
 189 bool GraphKit::has_exception_handler() {
 190   for (JVMState* jvmsp = jvms(); jvmsp != nullptr; jvmsp = jvmsp->caller()) {
 191     if (jvmsp->has_method() && jvmsp->method()->has_exception_handlers()) {
 192       return true;
 193     }
 194   }
 195   return false;
 196 }
 197 
 198 //------------------------------save_ex_oop------------------------------------
 199 // Save an exception without blowing stack contents or other JVM state.
 200 void GraphKit::set_saved_ex_oop(SafePointNode* ex_map, Node* ex_oop) {
 201   assert(!has_saved_ex_oop(ex_map), "clear ex-oop before setting again");
 202   ex_map->add_req(ex_oop);
 203   DEBUG_ONLY(verify_exception_state(ex_map));
 204 }
 205 
 206 inline static Node* common_saved_ex_oop(SafePointNode* ex_map, bool clear_it) {
 207   assert(GraphKit::has_saved_ex_oop(ex_map), "ex_oop must be there");
 208   Node* ex_oop = ex_map->in(ex_map->req()-1);
 209   if (clear_it)  ex_map->del_req(ex_map->req()-1);
 210   return ex_oop;
 211 }
 212 
 213 //-----------------------------saved_ex_oop------------------------------------
 214 // Recover a saved exception from its map.
 215 Node* GraphKit::saved_ex_oop(SafePointNode* ex_map) {
 216   return common_saved_ex_oop(ex_map, false);
 217 }
 218 
 219 //--------------------------clear_saved_ex_oop---------------------------------
 220 // Erase a previously saved exception from its map.
 221 Node* GraphKit::clear_saved_ex_oop(SafePointNode* ex_map) {
 222   return common_saved_ex_oop(ex_map, true);
 223 }
 224 
 225 #ifdef ASSERT
 226 //---------------------------has_saved_ex_oop----------------------------------
 227 // Erase a previously saved exception from its map.
 228 bool GraphKit::has_saved_ex_oop(SafePointNode* ex_map) {
 229   return ex_map->req() == ex_map->jvms()->endoff()+1;
 230 }
 231 #endif
 232 
 233 //-------------------------make_exception_state--------------------------------
 234 // Turn the current JVM state into an exception state, appending the ex_oop.
 235 SafePointNode* GraphKit::make_exception_state(Node* ex_oop) {
 236   sync_jvms();
 237   SafePointNode* ex_map = stop();  // do not manipulate this map any more
 238   set_saved_ex_oop(ex_map, ex_oop);
 239   return ex_map;
 240 }
 241 
 242 
 243 //--------------------------add_exception_state--------------------------------
 244 // Add an exception to my list of exceptions.
 245 void GraphKit::add_exception_state(SafePointNode* ex_map) {
 246   if (ex_map == nullptr || ex_map->control() == top()) {
 247     return;
 248   }
 249 #ifdef ASSERT
 250   verify_exception_state(ex_map);
 251   if (has_exceptions()) {
 252     assert(ex_map->jvms()->same_calls_as(_exceptions->jvms()), "all collected exceptions must come from the same place");
 253   }
 254 #endif
 255 
 256   // If there is already an exception of exactly this type, merge with it.
 257   // In particular, null-checks and other low-level exceptions common up here.
 258   Node*       ex_oop  = saved_ex_oop(ex_map);
 259   const Type* ex_type = _gvn.type(ex_oop);
 260   if (ex_oop == top()) {
 261     // No action needed.
 262     return;
 263   }
 264   assert(ex_type->isa_instptr(), "exception must be an instance");
 265   for (SafePointNode* e2 = _exceptions; e2 != nullptr; e2 = e2->next_exception()) {
 266     const Type* ex_type2 = _gvn.type(saved_ex_oop(e2));
 267     // We check sp also because call bytecodes can generate exceptions
 268     // both before and after arguments are popped!
 269     if (ex_type2 == ex_type
 270         && e2->_jvms->sp() == ex_map->_jvms->sp()) {
 271       combine_exception_states(ex_map, e2);
 272       return;
 273     }
 274   }
 275 
 276   // No pre-existing exception of the same type.  Chain it on the list.
 277   push_exception_state(ex_map);
 278 }
 279 
 280 //-----------------------add_exception_states_from-----------------------------
 281 void GraphKit::add_exception_states_from(JVMState* jvms) {
 282   SafePointNode* ex_map = jvms->map()->next_exception();
 283   if (ex_map != nullptr) {
 284     jvms->map()->set_next_exception(nullptr);
 285     for (SafePointNode* next_map; ex_map != nullptr; ex_map = next_map) {
 286       next_map = ex_map->next_exception();
 287       ex_map->set_next_exception(nullptr);
 288       add_exception_state(ex_map);
 289     }
 290   }
 291 }
 292 
 293 //-----------------------transfer_exceptions_into_jvms-------------------------
 294 JVMState* GraphKit::transfer_exceptions_into_jvms() {
 295   if (map() == nullptr) {
 296     // We need a JVMS to carry the exceptions, but the map has gone away.
 297     // Create a scratch JVMS, cloned from any of the exception states...
 298     if (has_exceptions()) {
 299       _map = _exceptions;
 300       _map = clone_map();
 301       _map->set_next_exception(nullptr);
 302       clear_saved_ex_oop(_map);
 303       DEBUG_ONLY(verify_map());
 304     } else {
 305       // ...or created from scratch
 306       JVMState* jvms = new (C) JVMState(_method, nullptr);
 307       jvms->set_bci(_bci);
 308       jvms->set_sp(_sp);
 309       jvms->set_map(new SafePointNode(TypeFunc::Parms, jvms));
 310       set_jvms(jvms);
 311       for (uint i = 0; i < map()->req(); i++)  map()->init_req(i, top());
 312       set_all_memory(top());
 313       while (map()->req() < jvms->endoff())  map()->add_req(top());
 314     }
 315     // (This is a kludge, in case you didn't notice.)
 316     set_control(top());
 317   }
 318   JVMState* jvms = sync_jvms();
 319   assert(!jvms->map()->has_exceptions(), "no exceptions on this map yet");
 320   jvms->map()->set_next_exception(_exceptions);
 321   _exceptions = nullptr;   // done with this set of exceptions
 322   return jvms;
 323 }
 324 
 325 static inline void add_n_reqs(Node* dstphi, Node* srcphi) {
 326   assert(is_hidden_merge(dstphi), "must be a special merge node");
 327   assert(is_hidden_merge(srcphi), "must be a special merge node");
 328   uint limit = srcphi->req();
 329   for (uint i = PhiNode::Input; i < limit; i++) {
 330     dstphi->add_req(srcphi->in(i));
 331   }
 332 }
 333 static inline void add_one_req(Node* dstphi, Node* src) {
 334   assert(is_hidden_merge(dstphi), "must be a special merge node");
 335   assert(!is_hidden_merge(src), "must not be a special merge node");
 336   dstphi->add_req(src);
 337 }
 338 
 339 //-----------------------combine_exception_states------------------------------
 340 // This helper function combines exception states by building phis on a
 341 // specially marked state-merging region.  These regions and phis are
 342 // untransformed, and can build up gradually.  The region is marked by
 343 // having a control input of its exception map, rather than null.  Such
 344 // regions do not appear except in this function, and in use_exception_state.
 345 void GraphKit::combine_exception_states(SafePointNode* ex_map, SafePointNode* phi_map) {
 346   if (failing_internal()) {
 347     return;  // dying anyway...
 348   }
 349   JVMState* ex_jvms = ex_map->_jvms;
 350   assert(ex_jvms->same_calls_as(phi_map->_jvms), "consistent call chains");
 351   assert(ex_jvms->stkoff() == phi_map->_jvms->stkoff(), "matching locals");
 352   assert(ex_jvms->sp() == phi_map->_jvms->sp(), "matching stack sizes");
 353   assert(ex_jvms->monoff() == phi_map->_jvms->monoff(), "matching JVMS");
 354   assert(ex_jvms->scloff() == phi_map->_jvms->scloff(), "matching scalar replaced objects");
 355   assert(ex_map->req() == phi_map->req(), "matching maps");
 356   uint tos = ex_jvms->stkoff() + ex_jvms->sp();
 357   Node*         hidden_merge_mark = root();
 358   Node*         region  = phi_map->control();
 359   MergeMemNode* phi_mem = phi_map->merged_memory();
 360   MergeMemNode* ex_mem  = ex_map->merged_memory();
 361   if (region->in(0) != hidden_merge_mark) {
 362     // The control input is not (yet) a specially-marked region in phi_map.
 363     // Make it so, and build some phis.
 364     region = new RegionNode(2);
 365     _gvn.set_type(region, Type::CONTROL);
 366     region->set_req(0, hidden_merge_mark);  // marks an internal ex-state
 367     region->init_req(1, phi_map->control());
 368     phi_map->set_control(region);
 369     Node* io_phi = PhiNode::make(region, phi_map->i_o(), Type::ABIO);
 370     record_for_igvn(io_phi);
 371     _gvn.set_type(io_phi, Type::ABIO);
 372     phi_map->set_i_o(io_phi);
 373     for (MergeMemStream mms(phi_mem); mms.next_non_empty(); ) {
 374       Node* m = mms.memory();
 375       Node* m_phi = PhiNode::make(region, m, Type::MEMORY, mms.adr_type(C));
 376       record_for_igvn(m_phi);
 377       _gvn.set_type(m_phi, Type::MEMORY);
 378       mms.set_memory(m_phi);
 379     }
 380   }
 381 
 382   // Either or both of phi_map and ex_map might already be converted into phis.
 383   Node* ex_control = ex_map->control();
 384   // if there is special marking on ex_map also, we add multiple edges from src
 385   bool add_multiple = (ex_control->in(0) == hidden_merge_mark);
 386   // how wide was the destination phi_map, originally?
 387   uint orig_width = region->req();
 388 
 389   if (add_multiple) {
 390     add_n_reqs(region, ex_control);
 391     add_n_reqs(phi_map->i_o(), ex_map->i_o());
 392   } else {
 393     // ex_map has no merges, so we just add single edges everywhere
 394     add_one_req(region, ex_control);
 395     add_one_req(phi_map->i_o(), ex_map->i_o());
 396   }
 397   for (MergeMemStream mms(phi_mem, ex_mem); mms.next_non_empty2(); ) {
 398     if (mms.is_empty()) {
 399       // get a copy of the base memory, and patch some inputs into it
 400       const TypePtr* adr_type = mms.adr_type(C);
 401       Node* phi = mms.force_memory()->as_Phi()->slice_memory(adr_type);
 402       assert(phi->as_Phi()->region() == mms.base_memory()->in(0), "");
 403       mms.set_memory(phi);
 404       // Prepare to append interesting stuff onto the newly sliced phi:
 405       while (phi->req() > orig_width)  phi->del_req(phi->req()-1);
 406     }
 407     // Append stuff from ex_map:
 408     if (add_multiple) {
 409       add_n_reqs(mms.memory(), mms.memory2());
 410     } else {
 411       add_one_req(mms.memory(), mms.memory2());
 412     }
 413   }
 414   uint limit = ex_map->req();
 415   for (uint i = TypeFunc::Parms; i < limit; i++) {
 416     // Skip everything in the JVMS after tos.  (The ex_oop follows.)
 417     if (i == tos)  i = ex_jvms->monoff();
 418     Node* src = ex_map->in(i);
 419     Node* dst = phi_map->in(i);
 420     if (src != dst) {
 421       PhiNode* phi;
 422       if (dst->in(0) != region) {
 423         dst = phi = PhiNode::make(region, dst, _gvn.type(dst));
 424         record_for_igvn(phi);
 425         _gvn.set_type(phi, phi->type());
 426         phi_map->set_req(i, dst);
 427         // Prepare to append interesting stuff onto the new phi:
 428         while (dst->req() > orig_width)  dst->del_req(dst->req()-1);
 429       } else {
 430         assert(dst->is_Phi(), "nobody else uses a hidden region");
 431         phi = dst->as_Phi();
 432       }
 433       if (add_multiple && src->in(0) == ex_control) {
 434         // Both are phis.
 435         add_n_reqs(dst, src);
 436       } else {
 437         while (dst->req() < region->req())  add_one_req(dst, src);
 438       }
 439       const Type* srctype = _gvn.type(src);
 440       if (phi->type() != srctype) {
 441         const Type* dsttype = phi->type()->meet_speculative(srctype);
 442         if (phi->type() != dsttype) {
 443           phi->set_type(dsttype);
 444           _gvn.set_type(phi, dsttype);
 445         }
 446       }
 447     }
 448   }
 449   phi_map->merge_replaced_nodes_with(ex_map);
 450 }
 451 
 452 //--------------------------use_exception_state--------------------------------
 453 Node* GraphKit::use_exception_state(SafePointNode* phi_map) {
 454   if (failing_internal()) { stop(); return top(); }
 455   Node* region = phi_map->control();
 456   Node* hidden_merge_mark = root();
 457   assert(phi_map->jvms()->map() == phi_map, "sanity: 1-1 relation");
 458   Node* ex_oop = clear_saved_ex_oop(phi_map);
 459   if (region->in(0) == hidden_merge_mark) {
 460     // Special marking for internal ex-states.  Process the phis now.
 461     region->set_req(0, region);  // now it's an ordinary region
 462     set_jvms(phi_map->jvms());   // ...so now we can use it as a map
 463     // Note: Setting the jvms also sets the bci and sp.
 464     set_control(_gvn.transform(region));
 465     uint tos = jvms()->stkoff() + sp();
 466     for (uint i = 1; i < tos; i++) {
 467       Node* x = phi_map->in(i);
 468       if (x->in(0) == region) {
 469         assert(x->is_Phi(), "expected a special phi");
 470         phi_map->set_req(i, _gvn.transform(x));
 471       }
 472     }
 473     for (MergeMemStream mms(merged_memory()); mms.next_non_empty(); ) {
 474       Node* x = mms.memory();
 475       if (x->in(0) == region) {
 476         assert(x->is_Phi(), "nobody else uses a hidden region");
 477         mms.set_memory(_gvn.transform(x));
 478       }
 479     }
 480     if (ex_oop->in(0) == region) {
 481       assert(ex_oop->is_Phi(), "expected a special phi");
 482       ex_oop = _gvn.transform(ex_oop);
 483     }
 484   } else {
 485     set_jvms(phi_map->jvms());
 486   }
 487 
 488   assert(!is_hidden_merge(phi_map->control()), "hidden ex. states cleared");
 489   assert(!is_hidden_merge(phi_map->i_o()), "hidden ex. states cleared");
 490   return ex_oop;
 491 }
 492 
 493 //---------------------------------java_bc-------------------------------------
 494 Bytecodes::Code GraphKit::java_bc() const {
 495   ciMethod* method = this->method();
 496   int       bci    = this->bci();
 497   if (method != nullptr && bci != InvocationEntryBci)
 498     return method->java_code_at_bci(bci);
 499   else
 500     return Bytecodes::_illegal;
 501 }
 502 
 503 void GraphKit::uncommon_trap_if_should_post_on_exceptions(Deoptimization::DeoptReason reason,
 504                                                           bool must_throw) {
 505     // if the exception capability is set, then we will generate code
 506     // to check the JavaThread.should_post_on_exceptions flag to see
 507     // if we actually need to report exception events (for this
 508     // thread).  If we don't need to report exception events, we will
 509     // take the normal fast path provided by add_exception_events.  If
 510     // exception event reporting is enabled for this thread, we will
 511     // take the uncommon_trap in the BuildCutout below.
 512 
 513     // first must access the should_post_on_exceptions_flag in this thread's JavaThread
 514     Node* jthread = _gvn.transform(new ThreadLocalNode());
 515     Node* adr = off_heap_plus_addr(jthread, in_bytes(JavaThread::should_post_on_exceptions_flag_offset()));
 516     Node* should_post_flag = make_load(control(), adr, TypeInt::INT, T_INT, MemNode::unordered);
 517 
 518     // Test the should_post_on_exceptions_flag vs. 0
 519     Node* chk = _gvn.transform( new CmpINode(should_post_flag, intcon(0)) );
 520     Node* tst = _gvn.transform( new BoolNode(chk, BoolTest::eq) );
 521 
 522     // Branch to slow_path if should_post_on_exceptions_flag was true
 523     { BuildCutout unless(this, tst, PROB_MAX);
 524       // Do not try anything fancy if we're notifying the VM on every throw.
 525       // Cf. case Bytecodes::_athrow in parse2.cpp.
 526       uncommon_trap(reason, Deoptimization::Action_none,
 527                     (ciKlass*)nullptr, (char*)nullptr, must_throw);
 528     }
 529 
 530 }
 531 
 532 //------------------------------builtin_throw----------------------------------
 533 void GraphKit::builtin_throw(Deoptimization::DeoptReason reason) {
 534   builtin_throw(reason, builtin_throw_exception(reason), /*allow_too_many_traps*/ true);
 535 }
 536 
 537 void GraphKit::builtin_throw(Deoptimization::DeoptReason reason,
 538                              ciInstance* ex_obj,
 539                              bool allow_too_many_traps) {
 540   // If this throw happens frequently, an uncommon trap might cause
 541   // a performance pothole.  If there is a local exception handler,
 542   // and if this particular bytecode appears to be deoptimizing often,
 543   // let us handle the throw inline, with a preconstructed instance.
 544   // Note:   If the deopt count has blown up, the uncommon trap
 545   // runtime is going to flush this nmethod, not matter what.
 546   if (is_builtin_throw_hot(reason)) {
 547     if (method()->can_omit_stack_trace() && ex_obj != nullptr) {
 548       // If the throw is local, we use a pre-existing instance and
 549       // punt on the backtrace.  This would lead to a missing backtrace
 550       // (a repeat of 4292742) if the backtrace object is ever asked
 551       // for its backtrace.
 552       // Fixing this remaining case of 4292742 requires some flavor of
 553       // escape analysis.  Leave that for the future.
 554       if (env()->jvmti_can_post_on_exceptions()) {
 555         // check if we must post exception events, take uncommon trap if so
 556         uncommon_trap_if_should_post_on_exceptions(reason, true /*must_throw*/);
 557         // here if should_post_on_exceptions is false
 558         // continue on with the normal codegen
 559       }
 560 
 561       // Cheat with a preallocated exception object.
 562       if (C->log() != nullptr)
 563         C->log()->elem("hot_throw preallocated='1' reason='%s'",
 564                        Deoptimization::trap_reason_name(reason));
 565       const TypeInstPtr* ex_con  = TypeInstPtr::make(ex_obj);
 566       Node*              ex_node = _gvn.transform(ConNode::make(ex_con));
 567 
 568       // Clear the detail message of the preallocated exception object.
 569       // Weblogic sometimes mutates the detail message of exceptions
 570       // using reflection.
 571       int offset = java_lang_Throwable::get_detailMessage_offset();
 572       const TypePtr* adr_typ = ex_con->add_offset(offset);
 573 
 574       Node *adr = basic_plus_adr(ex_node, ex_node, offset);
 575       const TypeOopPtr* val_type = TypeOopPtr::make_from_klass(env()->String_klass());
 576       Node *store = access_store_at(ex_node, adr, adr_typ, null(), val_type, T_OBJECT, IN_HEAP);
 577 
 578       if (!method()->has_exception_handlers()) {
 579         // We don't need to preserve the stack if there's no handler as the entire frame is going to be popped anyway.
 580         // This prevents issues with exception handling and late inlining.
 581         set_sp(0);
 582         clean_stack(0);
 583       }
 584 
 585       add_exception_state(make_exception_state(ex_node));
 586       return;
 587     } else if (builtin_throw_too_many_traps(reason, ex_obj)) {
 588       // We cannot afford to take too many traps here. Suffer in the interpreter instead.
 589       assert(allow_too_many_traps, "not allowed");
 590       if (C->log() != nullptr) {
 591         C->log()->elem("hot_throw preallocated='0' reason='%s' mcount='%d'",
 592                        Deoptimization::trap_reason_name(reason),
 593                        C->trap_count(reason));
 594       }
 595       uncommon_trap(reason, Deoptimization::Action_none,
 596                     (ciKlass*) nullptr, (char*) nullptr,
 597                     true /*must_throw*/);
 598       return;
 599     }
 600   }
 601 
 602   // %%% Maybe add entry to OptoRuntime which directly throws the exc.?
 603   // It won't be much cheaper than bailing to the interp., since we'll
 604   // have to pass up all the debug-info, and the runtime will have to
 605   // create the stack trace.
 606 
 607   // Usual case:  Bail to interpreter.
 608   // Reserve the right to recompile if we haven't seen anything yet.
 609 
 610   // "must_throw" prunes the JVM state to include only the stack, if there
 611   // are no local exception handlers.  This should cut down on register
 612   // allocation time and code size, by drastically reducing the number
 613   // of in-edges on the call to the uncommon trap.
 614   uncommon_trap(reason, Deoptimization::Action_maybe_recompile,
 615                 (ciKlass*) nullptr, (char*) nullptr,
 616                 true /*must_throw*/);
 617 }
 618 
 619 bool GraphKit::is_builtin_throw_hot(Deoptimization::DeoptReason reason) {
 620   // If this particular condition has not yet happened at this
 621   // bytecode, then use the uncommon trap mechanism, and allow for
 622   // a future recompilation if several traps occur here.
 623   // If the throw is hot, try to use a more complicated inline mechanism
 624   // which keeps execution inside the compiled code.
 625   if (ProfileTraps) {
 626     if (too_many_traps(reason)) {
 627       return true;
 628     }
 629     // (If there is no MDO at all, assume it is early in
 630     // execution, and that any deopts are part of the
 631     // startup transient, and don't need to be remembered.)
 632 
 633     // Also, if there is a local exception handler, treat all throws
 634     // as hot if there has been at least one in this method.
 635     if (C->trap_count(reason) != 0 &&
 636         method()->method_data()->trap_count(reason) != 0 &&
 637         has_exception_handler()) {
 638       return true;
 639     }
 640   }
 641   return false;
 642 }
 643 
 644 bool GraphKit::builtin_throw_too_many_traps(Deoptimization::DeoptReason reason,
 645                                             ciInstance* ex_obj) {
 646   if (is_builtin_throw_hot(reason)) {
 647     if (method()->can_omit_stack_trace() && ex_obj != nullptr) {
 648       return false; // no traps; throws preallocated exception instead
 649     }
 650     ciMethod* m = Deoptimization::reason_is_speculate(reason) ? C->method() : nullptr;
 651     if (method()->method_data()->trap_recompiled_at(bci(), m) ||
 652         C->too_many_traps(reason)) {
 653       return true;
 654     }
 655   }
 656   return false;
 657 }
 658 
 659 ciInstance* GraphKit::builtin_throw_exception(Deoptimization::DeoptReason reason) const {
 660   // Preallocated exception objects to use when we don't need the backtrace.
 661   switch (reason) {
 662   case Deoptimization::Reason_null_check:
 663     return env()->NullPointerException_instance();
 664   case Deoptimization::Reason_div0_check:
 665     return env()->ArithmeticException_instance();
 666   case Deoptimization::Reason_range_check:
 667     return env()->ArrayIndexOutOfBoundsException_instance();
 668   case Deoptimization::Reason_class_check:
 669     return env()->ClassCastException_instance();
 670   case Deoptimization::Reason_array_check:
 671     return env()->ArrayStoreException_instance();
 672   default:
 673     return nullptr;
 674   }
 675 }
 676 
 677 GraphKit::SavedState::SavedState(GraphKit* kit) :
 678   _kit(kit),
 679   _sp(kit->sp()),
 680   _jvms(kit->jvms()),
 681   _map(kit->clone_map()),
 682   _discarded(false)
 683 {
 684   for (DUIterator_Fast imax, i = kit->control()->fast_outs(imax); i < imax; i++) {
 685     Node* out = kit->control()->fast_out(i);
 686     if (out->is_CFG()) {
 687       _ctrl_succ.push(out);
 688     }
 689   }
 690 }
 691 
 692 GraphKit::SavedState::~SavedState() {
 693   if (_discarded) {
 694     _kit->destruct_map_clone(_map);
 695     return;
 696   }
 697   _kit->jvms()->set_map(_map);
 698   _kit->jvms()->set_sp(_sp);
 699   _map->set_jvms(_kit->jvms());
 700   _kit->set_map(_map);
 701   _kit->set_sp(_sp);
 702   for (DUIterator_Fast imax, i = _kit->control()->fast_outs(imax); i < imax; i++) {
 703     Node* out = _kit->control()->fast_out(i);
 704     if (out->is_CFG() && out->in(0) == _kit->control() && out != _kit->map() && !_ctrl_succ.member(out)) {
 705       _kit->_gvn.hash_delete(out);
 706       out->set_req(0, _kit->C->top());
 707       _kit->C->record_for_igvn(out);
 708       --i; --imax;
 709       _kit->_gvn.hash_find_insert(out);
 710     }
 711   }
 712 }
 713 
 714 void GraphKit::SavedState::discard() {
 715   _discarded = true;
 716 }
 717 
 718 
 719 //----------------------------PreserveJVMState---------------------------------
 720 PreserveJVMState::PreserveJVMState(GraphKit* kit, bool clone_map) {
 721   DEBUG_ONLY(kit->verify_map());
 722   _kit    = kit;
 723   _map    = kit->map();   // preserve the map
 724   _sp     = kit->sp();
 725   kit->set_map(clone_map ? kit->clone_map() : nullptr);
 726 #ifdef ASSERT
 727   _bci    = kit->bci();
 728   Parse* parser = kit->is_Parse();
 729   int block = (parser == nullptr || parser->block() == nullptr) ? -1 : parser->block()->rpo();
 730   _block  = block;
 731 #endif
 732 }
 733 PreserveJVMState::~PreserveJVMState() {
 734   GraphKit* kit = _kit;
 735 #ifdef ASSERT
 736   assert(kit->bci() == _bci, "bci must not shift");
 737   Parse* parser = kit->is_Parse();
 738   int block = (parser == nullptr || parser->block() == nullptr) ? -1 : parser->block()->rpo();
 739   assert(block == _block,    "block must not shift");
 740 #endif
 741   kit->set_map(_map);
 742   kit->set_sp(_sp);
 743 }
 744 
 745 
 746 //-----------------------------BuildCutout-------------------------------------
 747 BuildCutout::BuildCutout(GraphKit* kit, Node* p, float prob, float cnt)
 748   : PreserveJVMState(kit)
 749 {
 750   assert(p->is_Con() || p->is_Bool(), "test must be a bool");
 751   SafePointNode* outer_map = _map;   // preserved map is caller's
 752   SafePointNode* inner_map = kit->map();
 753   IfNode* iff = kit->create_and_map_if(outer_map->control(), p, prob, cnt);
 754   outer_map->set_control(kit->gvn().transform( new IfTrueNode(iff) ));
 755   inner_map->set_control(kit->gvn().transform( new IfFalseNode(iff) ));
 756 }
 757 BuildCutout::~BuildCutout() {
 758   GraphKit* kit = _kit;
 759   assert(kit->stopped(), "cutout code must stop, throw, return, etc.");
 760 }
 761 
 762 //---------------------------PreserveReexecuteState----------------------------
 763 PreserveReexecuteState::PreserveReexecuteState(GraphKit* kit) {
 764   assert(!kit->stopped(), "must call stopped() before");
 765   _kit    =    kit;
 766   _sp     =    kit->sp();
 767   _reexecute = kit->jvms()->_reexecute;
 768 }
 769 PreserveReexecuteState::~PreserveReexecuteState() {
 770   if (_kit->stopped()) return;
 771   _kit->jvms()->_reexecute = _reexecute;
 772   _kit->set_sp(_sp);
 773 }
 774 
 775 //------------------------------clone_map--------------------------------------
 776 // Implementation of PreserveJVMState
 777 //
 778 // Only clone_map(...) here. If this function is only used in the
 779 // PreserveJVMState class we may want to get rid of this extra
 780 // function eventually and do it all there.
 781 
 782 SafePointNode* GraphKit::clone_map() {
 783   if (map() == nullptr)  return nullptr;
 784 
 785   // Clone the memory edge first
 786   Node* mem = MergeMemNode::make(map()->memory());
 787   gvn().set_type_bottom(mem);
 788 
 789   SafePointNode *clonemap = (SafePointNode*)map()->clone();
 790   JVMState* jvms = this->jvms();
 791   JVMState* clonejvms = jvms->clone_shallow(C);
 792   clonemap->set_memory(mem);
 793   clonemap->set_jvms(clonejvms);
 794   clonejvms->set_map(clonemap);
 795   record_for_igvn(clonemap);
 796   gvn().set_type_bottom(clonemap);
 797   return clonemap;
 798 }
 799 
 800 //-----------------------------destruct_map_clone------------------------------
 801 //
 802 // Order of destruct is important to increase the likelyhood that memory can be re-used. We need
 803 // to destruct/free/delete in the exact opposite order as clone_map().
 804 void GraphKit::destruct_map_clone(SafePointNode* sfp) {
 805   if (sfp == nullptr) return;
 806 
 807   Node* mem = sfp->memory();
 808   JVMState* jvms = sfp->jvms();
 809 
 810   if (jvms != nullptr) {
 811     delete jvms;
 812   }
 813 
 814   remove_for_igvn(sfp);
 815   gvn().clear_type(sfp);
 816   sfp->destruct(&_gvn);
 817 
 818   if (mem != nullptr) {
 819     gvn().clear_type(mem);
 820     mem->destruct(&_gvn);
 821   }
 822 }
 823 
 824 //-----------------------------set_map_clone-----------------------------------
 825 void GraphKit::set_map_clone(SafePointNode* m) {
 826   _map = m;
 827   _map = clone_map();
 828   _map->set_next_exception(nullptr);
 829   DEBUG_ONLY(verify_map());
 830 }
 831 
 832 
 833 //----------------------------kill_dead_locals---------------------------------
 834 // Detect any locals which are known to be dead, and force them to top.
 835 void GraphKit::kill_dead_locals() {
 836   // Consult the liveness information for the locals.  If any
 837   // of them are unused, then they can be replaced by top().  This
 838   // should help register allocation time and cut down on the size
 839   // of the deoptimization information.
 840 
 841   // This call is made from many of the bytecode handling
 842   // subroutines called from the Big Switch in do_one_bytecode.
 843   // Every bytecode which might include a slow path is responsible
 844   // for killing its dead locals.  The more consistent we
 845   // are about killing deads, the fewer useless phis will be
 846   // constructed for them at various merge points.
 847 
 848   // bci can be -1 (InvocationEntryBci).  We return the entry
 849   // liveness for the method.
 850 
 851   if (method() == nullptr || method()->code_size() == 0) {
 852     // We are building a graph for a call to a native method.
 853     // All locals are live.
 854     return;
 855   }
 856 
 857   ResourceMark rm;
 858 
 859   // Consult the liveness information for the locals.  If any
 860   // of them are unused, then they can be replaced by top().  This
 861   // should help register allocation time and cut down on the size
 862   // of the deoptimization information.
 863   MethodLivenessResult live_locals = method()->liveness_at_bci(bci());
 864 
 865   int len = (int)live_locals.size();
 866   assert(len <= jvms()->loc_size(), "too many live locals");
 867   for (int local = 0; local < len; local++) {
 868     if (!live_locals.at(local)) {
 869       set_local(local, top());
 870     }
 871   }
 872 }
 873 
 874 #ifdef ASSERT
 875 //-------------------------dead_locals_are_killed------------------------------
 876 // Return true if all dead locals are set to top in the map.
 877 // Used to assert "clean" debug info at various points.
 878 bool GraphKit::dead_locals_are_killed() {
 879   if (method() == nullptr || method()->code_size() == 0) {
 880     // No locals need to be dead, so all is as it should be.
 881     return true;
 882   }
 883 
 884   // Make sure somebody called kill_dead_locals upstream.
 885   ResourceMark rm;
 886   for (JVMState* jvms = this->jvms(); jvms != nullptr; jvms = jvms->caller()) {
 887     if (jvms->loc_size() == 0)  continue;  // no locals to consult
 888     SafePointNode* map = jvms->map();
 889     ciMethod* method = jvms->method();
 890     int       bci    = jvms->bci();
 891     if (jvms == this->jvms()) {
 892       bci = this->bci();  // it might not yet be synched
 893     }
 894     MethodLivenessResult live_locals = method->liveness_at_bci(bci);
 895     int len = (int)live_locals.size();
 896     if (!live_locals.is_valid() || len == 0)
 897       // This method is trivial, or is poisoned by a breakpoint.
 898       return true;
 899     assert(len == jvms->loc_size(), "live map consistent with locals map");
 900     for (int local = 0; local < len; local++) {
 901       if (!live_locals.at(local) && map->local(jvms, local) != top()) {
 902         if (PrintMiscellaneous && (Verbose || WizardMode)) {
 903           tty->print_cr("Zombie local %d: ", local);
 904           jvms->dump();
 905         }
 906         return false;
 907       }
 908     }
 909   }
 910   return true;
 911 }
 912 
 913 #endif //ASSERT
 914 
 915 // Helper function for enforcing certain bytecodes to reexecute if deoptimization happens.
 916 static bool should_reexecute_implied_by_bytecode(JVMState *jvms, bool is_anewarray) {
 917   ciMethod* cur_method = jvms->method();
 918   int       cur_bci   = jvms->bci();
 919   if (cur_method != nullptr && cur_bci != InvocationEntryBci) {
 920     Bytecodes::Code code = cur_method->java_code_at_bci(cur_bci);
 921     return Interpreter::bytecode_should_reexecute(code) ||
 922            (is_anewarray && code == Bytecodes::_multianewarray);
 923     // Reexecute _multianewarray bytecode which was replaced with
 924     // sequence of [a]newarray. See Parse::do_multianewarray().
 925     //
 926     // Note: interpreter should not have it set since this optimization
 927     // is limited by dimensions and guarded by flag so in some cases
 928     // multianewarray() runtime calls will be generated and
 929     // the bytecode should not be reexecutes (stack will not be reset).
 930   } else {
 931     return false;
 932   }
 933 }
 934 
 935 // Helper function for adding JVMState and debug information to node
 936 void GraphKit::add_safepoint_edges(SafePointNode* call, bool must_throw) {
 937   // Add the safepoint edges to the call (or other safepoint).
 938 
 939   // Make sure dead locals are set to top.  This
 940   // should help register allocation time and cut down on the size
 941   // of the deoptimization information.
 942   assert(dead_locals_are_killed(), "garbage in debug info before safepoint");
 943 
 944   // Walk the inline list to fill in the correct set of JVMState's
 945   // Also fill in the associated edges for each JVMState.
 946 
 947   // If the bytecode needs to be reexecuted we need to put
 948   // the arguments back on the stack.
 949   const bool should_reexecute = jvms()->should_reexecute();
 950   JVMState* youngest_jvms = should_reexecute ? sync_jvms_for_reexecute() : sync_jvms();
 951 
 952   // NOTE: set_bci (called from sync_jvms) might reset the reexecute bit to
 953   // undefined if the bci is different.  This is normal for Parse but it
 954   // should not happen for LibraryCallKit because only one bci is processed.
 955   assert(!is_LibraryCallKit() || (jvms()->should_reexecute() == should_reexecute),
 956          "in LibraryCallKit the reexecute bit should not change");
 957 
 958   // If we are guaranteed to throw, we can prune everything but the
 959   // input to the current bytecode.
 960   bool can_prune_locals = false;
 961   uint stack_slots_not_pruned = 0;
 962   int inputs = 0, depth = 0;
 963   if (must_throw) {
 964     assert(method() == youngest_jvms->method(), "sanity");
 965     if (compute_stack_effects(inputs, depth)) {
 966       can_prune_locals = true;
 967       stack_slots_not_pruned = inputs;
 968     }
 969   }
 970 
 971   if (env()->should_retain_local_variables()) {
 972     // At any safepoint, this method can get breakpointed, which would
 973     // then require an immediate deoptimization.
 974     can_prune_locals = false;  // do not prune locals
 975     stack_slots_not_pruned = 0;
 976   }
 977 
 978   // do not scribble on the input jvms
 979   JVMState* out_jvms = youngest_jvms->clone_deep(C);
 980   call->set_jvms(out_jvms); // Start jvms list for call node
 981 
 982   // For a known set of bytecodes, the interpreter should reexecute them if
 983   // deoptimization happens. We set the reexecute state for them here
 984   if (out_jvms->is_reexecute_undefined() && //don't change if already specified
 985       should_reexecute_implied_by_bytecode(out_jvms, call->is_AllocateArray())) {
 986 #ifdef ASSERT
 987     int inputs = 0, not_used; // initialized by GraphKit::compute_stack_effects()
 988     assert(method() == youngest_jvms->method(), "sanity");
 989     assert(compute_stack_effects(inputs, not_used), "unknown bytecode: %s", Bytecodes::name(java_bc()));
 990     assert(out_jvms->sp() >= (uint)inputs, "not enough operands for reexecution");
 991 #endif // ASSERT
 992     out_jvms->set_should_reexecute(true); //NOTE: youngest_jvms not changed
 993   }
 994 
 995   // Presize the call:
 996   DEBUG_ONLY(uint non_debug_edges = call->req());
 997   call->add_req_batch(top(), youngest_jvms->debug_depth());
 998   assert(call->req() == non_debug_edges + youngest_jvms->debug_depth(), "");
 999 
1000   // Set up edges so that the call looks like this:
1001   //  Call [state:] ctl io mem fptr retadr
1002   //       [parms:] parm0 ... parmN
1003   //       [root:]  loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN
1004   //    [...mid:]   loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN [...]
1005   //       [young:] loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN
1006   // Note that caller debug info precedes callee debug info.
1007 
1008   // Fill pointer walks backwards from "young:" to "root:" in the diagram above:
1009   uint debug_ptr = call->req();
1010 
1011   // Loop over the map input edges associated with jvms, add them
1012   // to the call node, & reset all offsets to match call node array.
1013   for (JVMState* in_jvms = youngest_jvms; in_jvms != nullptr; ) {
1014     uint debug_end   = debug_ptr;
1015     uint debug_start = debug_ptr - in_jvms->debug_size();
1016     debug_ptr = debug_start;  // back up the ptr
1017 
1018     uint p = debug_start;  // walks forward in [debug_start, debug_end)
1019     uint j, k, l;
1020     SafePointNode* in_map = in_jvms->map();
1021     out_jvms->set_map(call);
1022 
1023     if (can_prune_locals) {
1024       assert(in_jvms->method() == out_jvms->method(), "sanity");
1025       // If the current throw can reach an exception handler in this JVMS,
1026       // then we must keep everything live that can reach that handler.
1027       // As a quick and dirty approximation, we look for any handlers at all.
1028       if (in_jvms->method()->has_exception_handlers()) {
1029         can_prune_locals = false;
1030       }
1031     }
1032 
1033     // Add the Locals
1034     k = in_jvms->locoff();
1035     l = in_jvms->loc_size();
1036     out_jvms->set_locoff(p);
1037     if (!can_prune_locals) {
1038       for (j = 0; j < l; j++)
1039         call->set_req(p++, in_map->in(k+j));
1040     } else {
1041       p += l;  // already set to top above by add_req_batch
1042     }
1043 
1044     // Add the Expression Stack
1045     k = in_jvms->stkoff();
1046     l = in_jvms->sp();
1047     out_jvms->set_stkoff(p);
1048     if (!can_prune_locals) {
1049       for (j = 0; j < l; j++)
1050         call->set_req(p++, in_map->in(k+j));
1051     } else if (can_prune_locals && stack_slots_not_pruned != 0) {
1052       // Divide stack into {S0,...,S1}, where S0 is set to top.
1053       uint s1 = stack_slots_not_pruned;
1054       stack_slots_not_pruned = 0;  // for next iteration
1055       if (s1 > l)  s1 = l;
1056       uint s0 = l - s1;
1057       p += s0;  // skip the tops preinstalled by add_req_batch
1058       for (j = s0; j < l; j++)
1059         call->set_req(p++, in_map->in(k+j));
1060     } else {
1061       p += l;  // already set to top above by add_req_batch
1062     }
1063 
1064     // Add the Monitors
1065     k = in_jvms->monoff();
1066     l = in_jvms->mon_size();
1067     out_jvms->set_monoff(p);
1068     for (j = 0; j < l; j++)
1069       call->set_req(p++, in_map->in(k+j));
1070 
1071     // Copy any scalar object fields.
1072     k = in_jvms->scloff();
1073     l = in_jvms->scl_size();
1074     out_jvms->set_scloff(p);
1075     for (j = 0; j < l; j++)
1076       call->set_req(p++, in_map->in(k+j));
1077 
1078     // Finish the new jvms.
1079     out_jvms->set_endoff(p);
1080 
1081     assert(out_jvms->endoff()     == debug_end,             "fill ptr must match");
1082     assert(out_jvms->depth()      == in_jvms->depth(),      "depth must match");
1083     assert(out_jvms->loc_size()   == in_jvms->loc_size(),   "size must match");
1084     assert(out_jvms->mon_size()   == in_jvms->mon_size(),   "size must match");
1085     assert(out_jvms->scl_size()   == in_jvms->scl_size(),   "size must match");
1086     assert(out_jvms->debug_size() == in_jvms->debug_size(), "size must match");
1087 
1088     // Update the two tail pointers in parallel.
1089     out_jvms = out_jvms->caller();
1090     in_jvms  = in_jvms->caller();
1091   }
1092 
1093   assert(debug_ptr == non_debug_edges, "debug info must fit exactly");
1094 
1095   // Test the correctness of JVMState::debug_xxx accessors:
1096   assert(call->jvms()->debug_start() == non_debug_edges, "");
1097   assert(call->jvms()->debug_end()   == call->req(), "");
1098   assert(call->jvms()->debug_depth() == call->req() - non_debug_edges, "");
1099 }
1100 
1101 bool GraphKit::compute_stack_effects(int& inputs, int& depth) {
1102   Bytecodes::Code code = java_bc();
1103   if (code == Bytecodes::_wide) {
1104     code = method()->java_code_at_bci(bci() + 1);
1105   }
1106 
1107   if (code != Bytecodes::_illegal) {
1108     depth = Bytecodes::depth(code); // checkcast=0, athrow=-1
1109   }
1110 
1111   auto rsize = [&]() {
1112     assert(code != Bytecodes::_illegal, "code is illegal!");
1113     BasicType rtype = Bytecodes::result_type(code); // checkcast=P, athrow=V
1114     return (rtype < T_CONFLICT) ? type2size[rtype] : 0;
1115   };
1116 
1117   switch (code) {
1118   case Bytecodes::_illegal:
1119     return false;
1120 
1121   case Bytecodes::_ldc:
1122   case Bytecodes::_ldc_w:
1123   case Bytecodes::_ldc2_w:
1124     inputs = 0;
1125     break;
1126 
1127   case Bytecodes::_dup:         inputs = 1;  break;
1128   case Bytecodes::_dup_x1:      inputs = 2;  break;
1129   case Bytecodes::_dup_x2:      inputs = 3;  break;
1130   case Bytecodes::_dup2:        inputs = 2;  break;
1131   case Bytecodes::_dup2_x1:     inputs = 3;  break;
1132   case Bytecodes::_dup2_x2:     inputs = 4;  break;
1133   case Bytecodes::_swap:        inputs = 2;  break;
1134   case Bytecodes::_arraylength: inputs = 1;  break;
1135 
1136   case Bytecodes::_getstatic:
1137   case Bytecodes::_putstatic:
1138   case Bytecodes::_getfield:
1139   case Bytecodes::_putfield:
1140     {
1141       bool ignored_will_link;
1142       ciField* field = method()->get_field_at_bci(bci(), ignored_will_link);
1143       int      size  = field->type()->size();
1144       bool is_get = (depth >= 0), is_static = (depth & 1);
1145       inputs = (is_static ? 0 : 1);
1146       if (is_get) {
1147         depth = size - inputs;
1148       } else {
1149         inputs += size;        // putxxx pops the value from the stack
1150         depth = - inputs;
1151       }
1152     }
1153     break;
1154 
1155   case Bytecodes::_invokevirtual:
1156   case Bytecodes::_invokespecial:
1157   case Bytecodes::_invokestatic:
1158   case Bytecodes::_invokedynamic:
1159   case Bytecodes::_invokeinterface:
1160     {
1161       bool ignored_will_link;
1162       ciSignature* declared_signature = nullptr;
1163       ciMethod* ignored_callee = method()->get_method_at_bci(bci(), ignored_will_link, &declared_signature);
1164       assert(declared_signature != nullptr, "cannot be null");
1165       inputs   = declared_signature->arg_size_for_bc(code);
1166       int size = declared_signature->return_type()->size();
1167       depth = size - inputs;
1168     }
1169     break;
1170 
1171   case Bytecodes::_multianewarray:
1172     {
1173       ciBytecodeStream iter(method());
1174       iter.reset_to_bci(bci());
1175       iter.next();
1176       inputs = iter.get_dimensions();
1177       assert(rsize() == 1, "");
1178       depth = 1 - inputs;
1179     }
1180     break;
1181 
1182   case Bytecodes::_ireturn:
1183   case Bytecodes::_lreturn:
1184   case Bytecodes::_freturn:
1185   case Bytecodes::_dreturn:
1186   case Bytecodes::_areturn:
1187     assert(rsize() == -depth, "");
1188     inputs = -depth;
1189     break;
1190 
1191   case Bytecodes::_jsr:
1192   case Bytecodes::_jsr_w:
1193     inputs = 0;
1194     depth  = 1;                  // S.B. depth=1, not zero
1195     break;
1196 
1197   default:
1198     // bytecode produces a typed result
1199     inputs = rsize() - depth;
1200     assert(inputs >= 0, "");
1201     break;
1202   }
1203 
1204 #ifdef ASSERT
1205   // spot check
1206   int outputs = depth + inputs;
1207   assert(outputs >= 0, "sanity");
1208   switch (code) {
1209   case Bytecodes::_checkcast: assert(inputs == 1 && outputs == 1, ""); break;
1210   case Bytecodes::_athrow:    assert(inputs == 1 && outputs == 0, ""); break;
1211   case Bytecodes::_aload_0:   assert(inputs == 0 && outputs == 1, ""); break;
1212   case Bytecodes::_return:    assert(inputs == 0 && outputs == 0, ""); break;
1213   case Bytecodes::_drem:      assert(inputs == 4 && outputs == 2, ""); break;
1214   default:                    break;
1215   }
1216 #endif //ASSERT
1217 
1218   return true;
1219 }
1220 
1221 
1222 
1223 //------------------------------basic_plus_adr---------------------------------
1224 Node* GraphKit::basic_plus_adr(Node* base, Node* ptr, Node* offset) {
1225   // short-circuit a common case
1226   if (offset == MakeConX(0)) {
1227     return ptr;
1228   }
1229 #ifdef ASSERT
1230   // Both 32-bit and 64-bit zeros should have been handled by the previous `if`
1231   // statement, so if we see either 32-bit or 64-bit zeros here, then we have a
1232   // problem.
1233   if (offset->is_Con()) {
1234     const Type* t = offset->bottom_type();
1235     bool is_zero_int = t->isa_int() && t->is_int()->get_con() == 0;
1236     bool is_zero_long = t->isa_long() && t->is_long()->get_con() == 0;
1237     assert(!is_zero_int && !is_zero_long,
1238            "Unexpected zero offset - should have matched MakeConX(0)");
1239   }
1240 #endif
1241   return _gvn.transform(AddPNode::make_with_base(base, ptr, offset));
1242 }
1243 
1244 Node* GraphKit::ConvI2L(Node* offset) {
1245   // short-circuit a common case
1246   jint offset_con = find_int_con(offset, Type::OffsetBot);
1247   if (offset_con != Type::OffsetBot) {
1248     return longcon((jlong) offset_con);
1249   }
1250   return _gvn.transform( new ConvI2LNode(offset));
1251 }
1252 
1253 Node* GraphKit::ConvI2UL(Node* offset) {
1254   juint offset_con = (juint) find_int_con(offset, Type::OffsetBot);
1255   if (offset_con != (juint) Type::OffsetBot) {
1256     return longcon((julong) offset_con);
1257   }
1258   Node* conv = _gvn.transform( new ConvI2LNode(offset));
1259   Node* mask = _gvn.transform(ConLNode::make((julong) max_juint));
1260   return _gvn.transform( new AndLNode(conv, mask) );
1261 }
1262 
1263 Node* GraphKit::ConvL2I(Node* offset) {
1264   // short-circuit a common case
1265   jlong offset_con = find_long_con(offset, (jlong)Type::OffsetBot);
1266   if (offset_con != (jlong)Type::OffsetBot) {
1267     return intcon((int) offset_con);
1268   }
1269   return _gvn.transform( new ConvL2INode(offset));
1270 }
1271 
1272 //-------------------------load_object_klass-----------------------------------
1273 Node* GraphKit::load_object_klass(Node* obj) {
1274   // Special-case a fresh allocation to avoid building nodes:
1275   Node* akls = AllocateNode::Ideal_klass(obj, &_gvn);
1276   if (akls != nullptr)  return akls;
1277   Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes());
1278   return _gvn.transform(LoadKlassNode::make(_gvn, immutable_memory(), k_adr, TypeInstPtr::KLASS));
1279 }
1280 
1281 //-------------------------load_array_length-----------------------------------
1282 Node* GraphKit::load_array_length(Node* array) {
1283   // Special-case a fresh allocation to avoid building nodes:
1284   AllocateArrayNode* alloc = AllocateArrayNode::Ideal_array_allocation(array);
1285   Node *alen;
1286   if (alloc == nullptr) {
1287     Node *r_adr = basic_plus_adr(array, arrayOopDesc::length_offset_in_bytes());
1288     alen = _gvn.transform( new LoadRangeNode(nullptr, immutable_memory(), r_adr, TypeInt::POS));
1289   } else {
1290     alen = array_ideal_length(alloc, _gvn.type(array)->is_oopptr(), false);
1291   }
1292   return alen;
1293 }
1294 
1295 Node* GraphKit::array_ideal_length(AllocateArrayNode* alloc,
1296                                    const TypeOopPtr* oop_type,
1297                                    bool replace_length_in_map) {
1298   Node* length = alloc->Ideal_length();
1299   if (replace_length_in_map == false || map()->find_edge(length) >= 0) {
1300     Node* ccast = alloc->make_ideal_length(oop_type, &_gvn);
1301     if (ccast != length) {
1302       // do not transform ccast here, it might convert to top node for
1303       // negative array length and break assumptions in parsing stage.
1304       _gvn.set_type_bottom(ccast);
1305       record_for_igvn(ccast);
1306       if (replace_length_in_map) {
1307         replace_in_map(length, ccast);
1308       }
1309       return ccast;
1310     }
1311   }
1312   return length;
1313 }
1314 
1315 //------------------------------do_null_check----------------------------------
1316 // Helper function to do a null pointer check.  Returned value is
1317 // the incoming address with null casted away.  You are allowed to use the
1318 // not-null value only if you are control dependent on the test.
1319 #ifndef PRODUCT
1320 extern uint explicit_null_checks_inserted,
1321             explicit_null_checks_elided;
1322 #endif
1323 Node* GraphKit::null_check_common(Node* value, BasicType type,
1324                                   // optional arguments for variations:
1325                                   bool assert_null,
1326                                   Node* *null_control,
1327                                   bool speculative) {
1328   assert(!assert_null || null_control == nullptr, "not both at once");
1329   if (stopped())  return top();
1330   NOT_PRODUCT(explicit_null_checks_inserted++);
1331 
1332   // Construct null check
1333   Node *chk = nullptr;
1334   switch(type) {
1335     case T_LONG   : chk = new CmpLNode(value, _gvn.zerocon(T_LONG)); break;
1336     case T_INT    : chk = new CmpINode(value, _gvn.intcon(0)); break;
1337     case T_ARRAY  : // fall through
1338       type = T_OBJECT;  // simplify further tests
1339     case T_OBJECT : {
1340       const Type *t = _gvn.type( value );
1341 
1342       const TypeOopPtr* tp = t->isa_oopptr();
1343       if (tp != nullptr && !tp->is_loaded()
1344           // Only for do_null_check, not any of its siblings:
1345           && !assert_null && null_control == nullptr) {
1346         // Usually, any field access or invocation on an unloaded oop type
1347         // will simply fail to link, since the statically linked class is
1348         // likely also to be unloaded.  However, in -Xcomp mode, sometimes
1349         // the static class is loaded but the sharper oop type is not.
1350         // Rather than checking for this obscure case in lots of places,
1351         // we simply observe that a null check on an unloaded class
1352         // will always be followed by a nonsense operation, so we
1353         // can just issue the uncommon trap here.
1354         // Our access to the unloaded class will only be correct
1355         // after it has been loaded and initialized, which requires
1356         // a trip through the interpreter.
1357         ciKlass* klass = tp->unloaded_klass();
1358 #ifndef PRODUCT
1359         if (WizardMode) { tty->print("Null check of unloaded "); klass->print(); tty->cr(); }
1360 #endif
1361         uncommon_trap(Deoptimization::Reason_unloaded,
1362                       Deoptimization::Action_reinterpret,
1363                       klass, "!loaded");
1364         return top();
1365       }
1366 
1367       if (assert_null) {
1368         // See if the type is contained in NULL_PTR.
1369         // If so, then the value is already null.
1370         if (t->higher_equal(TypePtr::NULL_PTR)) {
1371           NOT_PRODUCT(explicit_null_checks_elided++);
1372           return value;           // Elided null assert quickly!
1373         }
1374       } else {
1375         // See if mixing in the null pointer changes type.
1376         // If so, then the null pointer was not allowed in the original
1377         // type.  In other words, "value" was not-null.
1378         if (t->meet(TypePtr::NULL_PTR) != t->remove_speculative()) {
1379           // same as: if (!TypePtr::NULL_PTR->higher_equal(t)) ...
1380           NOT_PRODUCT(explicit_null_checks_elided++);
1381           return value;           // Elided null check quickly!
1382         }
1383       }
1384       chk = new CmpPNode( value, null() );
1385       break;
1386     }
1387 
1388     default:
1389       fatal("unexpected type: %s", type2name(type));
1390   }
1391   assert(chk != nullptr, "sanity check");
1392   chk = _gvn.transform(chk);
1393 
1394   BoolTest::mask btest = assert_null ? BoolTest::eq : BoolTest::ne;
1395   BoolNode *btst = new BoolNode( chk, btest);
1396   Node   *tst = _gvn.transform( btst );
1397 
1398   //-----------
1399   // if peephole optimizations occurred, a prior test existed.
1400   // If a prior test existed, maybe it dominates as we can avoid this test.
1401   if (tst != btst && type == T_OBJECT) {
1402     // At this point we want to scan up the CFG to see if we can
1403     // find an identical test (and so avoid this test altogether).
1404     Node *cfg = control();
1405     int depth = 0;
1406     while( depth < 16 ) {       // Limit search depth for speed
1407       if( cfg->Opcode() == Op_IfTrue &&
1408           cfg->in(0)->in(1) == tst ) {
1409         // Found prior test.  Use "cast_not_null" to construct an identical
1410         // CastPP (and hence hash to) as already exists for the prior test.
1411         // Return that casted value.
1412         if (assert_null) {
1413           replace_in_map(value, null());
1414           return null();  // do not issue the redundant test
1415         }
1416         Node *oldcontrol = control();
1417         set_control(cfg);
1418         Node *res = cast_not_null(value);
1419         set_control(oldcontrol);
1420         NOT_PRODUCT(explicit_null_checks_elided++);
1421         return res;
1422       }
1423       cfg = IfNode::up_one_dom(cfg, /*linear_only=*/ true);
1424       if (cfg == nullptr)  break;  // Quit at region nodes
1425       depth++;
1426     }
1427   }
1428 
1429   //-----------
1430   // Branch to failure if null
1431   float ok_prob = PROB_MAX;  // a priori estimate:  nulls never happen
1432   Deoptimization::DeoptReason reason;
1433   if (assert_null) {
1434     reason = Deoptimization::reason_null_assert(speculative);
1435   } else if (type == T_OBJECT) {
1436     reason = Deoptimization::reason_null_check(speculative);
1437   } else {
1438     reason = Deoptimization::Reason_div0_check;
1439   }
1440   // %%% Since Reason_unhandled is not recorded on a per-bytecode basis,
1441   // ciMethodData::has_trap_at will return a conservative -1 if any
1442   // must-be-null assertion has failed.  This could cause performance
1443   // problems for a method after its first do_null_assert failure.
1444   // Consider using 'Reason_class_check' instead?
1445 
1446   // To cause an implicit null check, we set the not-null probability
1447   // to the maximum (PROB_MAX).  For an explicit check the probability
1448   // is set to a smaller value.
1449   if (null_control != nullptr || too_many_traps(reason)) {
1450     // probability is less likely
1451     ok_prob =  PROB_LIKELY_MAG(3);
1452   } else if (!assert_null &&
1453              (ImplicitNullCheckThreshold > 0) &&
1454              method() != nullptr &&
1455              (method()->method_data()->trap_count(reason)
1456               >= (uint)ImplicitNullCheckThreshold)) {
1457     ok_prob =  PROB_LIKELY_MAG(3);
1458   }
1459 
1460   if (null_control != nullptr) {
1461     IfNode* iff = create_and_map_if(control(), tst, ok_prob, COUNT_UNKNOWN);
1462     Node* null_true = _gvn.transform( new IfFalseNode(iff));
1463     set_control(      _gvn.transform( new IfTrueNode(iff)));
1464 #ifndef PRODUCT
1465     if (null_true == top()) {
1466       explicit_null_checks_elided++;
1467     }
1468 #endif
1469     (*null_control) = null_true;
1470   } else {
1471     BuildCutout unless(this, tst, ok_prob);
1472     // Check for optimizer eliding test at parse time
1473     if (stopped()) {
1474       // Failure not possible; do not bother making uncommon trap.
1475       NOT_PRODUCT(explicit_null_checks_elided++);
1476     } else if (assert_null) {
1477       uncommon_trap(reason,
1478                     Deoptimization::Action_make_not_entrant,
1479                     nullptr, "assert_null");
1480     } else {
1481       replace_in_map(value, zerocon(type));
1482       builtin_throw(reason);
1483     }
1484   }
1485 
1486   // Must throw exception, fall-thru not possible?
1487   if (stopped()) {
1488     return top();               // No result
1489   }
1490 
1491   if (assert_null) {
1492     // Cast obj to null on this path.
1493     replace_in_map(value, zerocon(type));
1494     return zerocon(type);
1495   }
1496 
1497   // Cast obj to not-null on this path, if there is no null_control.
1498   // (If there is a null_control, a non-null value may come back to haunt us.)
1499   if (type == T_OBJECT) {
1500     Node* cast = cast_not_null(value, false);
1501     if (null_control == nullptr || (*null_control) == top())
1502       replace_in_map(value, cast);
1503     value = cast;
1504   }
1505 
1506   return value;
1507 }
1508 
1509 
1510 //------------------------------cast_not_null----------------------------------
1511 // Cast obj to not-null on this path
1512 Node* GraphKit::cast_not_null(Node* obj, bool do_replace_in_map) {
1513   const Type *t = _gvn.type(obj);
1514   const Type *t_not_null = t->join_speculative(TypePtr::NOTNULL);
1515   // Object is already not-null?
1516   if( t == t_not_null ) return obj;
1517 
1518   Node* cast = new CastPPNode(control(), obj,t_not_null);
1519   cast = _gvn.transform( cast );
1520 
1521   // Scan for instances of 'obj' in the current JVM mapping.
1522   // These instances are known to be not-null after the test.
1523   if (do_replace_in_map)
1524     replace_in_map(obj, cast);
1525 
1526   return cast;                  // Return casted value
1527 }
1528 
1529 // Sometimes in intrinsics, we implicitly know an object is not null
1530 // (there's no actual null check) so we can cast it to not null. In
1531 // the course of optimizations, the input to the cast can become null.
1532 // In that case that data path will die and we need the control path
1533 // to become dead as well to keep the graph consistent. So we have to
1534 // add a check for null for which one branch can't be taken. It uses
1535 // an OpaqueConstantBool node that will cause the check to be removed after loop
1536 // opts so the test goes away and the compiled code doesn't execute a
1537 // useless check.
1538 Node* GraphKit::must_be_not_null(Node* value, bool do_replace_in_map) {
1539   if (!TypePtr::NULL_PTR->higher_equal(_gvn.type(value))) {
1540     return value;
1541   }
1542   Node* chk = _gvn.transform(new CmpPNode(value, null()));
1543   Node* tst = _gvn.transform(new BoolNode(chk, BoolTest::ne));
1544   Node* opaq = _gvn.transform(new OpaqueConstantBoolNode(C, tst, true));
1545   IfNode* iff = new IfNode(control(), opaq, PROB_MAX, COUNT_UNKNOWN);
1546   _gvn.set_type(iff, iff->Value(&_gvn));
1547   if (!tst->is_Con()) {
1548     record_for_igvn(iff);
1549   }
1550   Node *if_f = _gvn.transform(new IfFalseNode(iff));
1551   Node *frame = _gvn.transform(new ParmNode(C->start(), TypeFunc::FramePtr));
1552   halt(if_f, frame, "unexpected null in intrinsic");
1553   Node *if_t = _gvn.transform(new IfTrueNode(iff));
1554   set_control(if_t);
1555   return cast_not_null(value, do_replace_in_map);
1556 }
1557 
1558 
1559 //--------------------------replace_in_map-------------------------------------
1560 void GraphKit::replace_in_map(Node* old, Node* neww) {
1561   if (old == neww) {
1562     return;
1563   }
1564 
1565   map()->replace_edge(old, neww);
1566 
1567   // Note: This operation potentially replaces any edge
1568   // on the map.  This includes locals, stack, and monitors
1569   // of the current (innermost) JVM state.
1570 
1571   // don't let inconsistent types from profiling escape this
1572   // method
1573 
1574   const Type* told = _gvn.type(old);
1575   const Type* tnew = _gvn.type(neww);
1576 
1577   if (!tnew->higher_equal(told)) {
1578     return;
1579   }
1580 
1581   map()->record_replaced_node(old, neww);
1582 }
1583 
1584 
1585 //=============================================================================
1586 //--------------------------------memory---------------------------------------
1587 Node* GraphKit::memory(uint alias_idx) {
1588   MergeMemNode* mem = merged_memory();
1589   Node* p = mem->memory_at(alias_idx);
1590   assert(p != mem->empty_memory(), "empty");
1591   _gvn.set_type(p, Type::MEMORY);  // must be mapped
1592   return p;
1593 }
1594 
1595 //-----------------------------reset_memory------------------------------------
1596 Node* GraphKit::reset_memory() {
1597   Node* mem = map()->memory();
1598   // do not use this node for any more parsing!
1599   DEBUG_ONLY( map()->set_memory((Node*)nullptr) );
1600   return _gvn.transform( mem );
1601 }
1602 
1603 //------------------------------set_all_memory---------------------------------
1604 void GraphKit::set_all_memory(Node* newmem) {
1605   Node* mergemem = MergeMemNode::make(newmem);
1606   gvn().set_type_bottom(mergemem);
1607   map()->set_memory(mergemem);
1608 }
1609 
1610 //------------------------------set_all_memory_call----------------------------
1611 void GraphKit::set_all_memory_call(Node* call, bool separate_io_proj) {
1612   Node* newmem = _gvn.transform( new ProjNode(call, TypeFunc::Memory, separate_io_proj) );
1613   set_all_memory(newmem);
1614 }
1615 
1616 //=============================================================================
1617 //
1618 // parser factory methods for MemNodes
1619 //
1620 // These are layered on top of the factory methods in LoadNode and StoreNode,
1621 // and integrate with the parser's memory state and _gvn engine.
1622 //
1623 
1624 // factory methods in "int adr_idx"
1625 Node* GraphKit::make_load(Node* ctl, Node* adr, const Type* t, BasicType bt,
1626                           MemNode::MemOrd mo,
1627                           LoadNode::ControlDependency control_dependency,
1628                           bool require_atomic_access,
1629                           bool unaligned,
1630                           bool mismatched,
1631                           bool unsafe,
1632                           uint8_t barrier_data) {
1633   int adr_idx = C->get_alias_index(_gvn.type(adr)->isa_ptr());
1634   assert(adr_idx != Compile::AliasIdxTop, "use other make_load factory" );
1635   const TypePtr* adr_type = nullptr; // debug-mode-only argument
1636   DEBUG_ONLY(adr_type = C->get_adr_type(adr_idx));
1637   Node* mem = memory(adr_idx);
1638   Node* ld = LoadNode::make(_gvn, ctl, mem, adr, adr_type, t, bt, mo, control_dependency, require_atomic_access, unaligned, mismatched, unsafe, barrier_data);
1639   ld = _gvn.transform(ld);
1640   if (((bt == T_OBJECT) && C->do_escape_analysis()) || C->eliminate_boxing()) {
1641     // Improve graph before escape analysis and boxing elimination.
1642     record_for_igvn(ld);
1643     if (ld->is_DecodeN()) {
1644       // Also record the actual load (LoadN) in case ld is DecodeN. In some
1645       // rare corner cases, ld->in(1) can be something other than LoadN (e.g.,
1646       // a Phi). Recording such cases is still perfectly sound, but may be
1647       // unnecessary and result in some minor IGVN overhead.
1648       record_for_igvn(ld->in(1));
1649     }
1650   }
1651   return ld;
1652 }
1653 
1654 Node* GraphKit::store_to_memory(Node* ctl, Node* adr, Node *val, BasicType bt,
1655                                 MemNode::MemOrd mo,
1656                                 bool require_atomic_access,
1657                                 bool unaligned,
1658                                 bool mismatched,
1659                                 bool unsafe,
1660                                 int barrier_data) {
1661   int adr_idx = C->get_alias_index(_gvn.type(adr)->isa_ptr());
1662   assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
1663   const TypePtr* adr_type = nullptr;
1664   DEBUG_ONLY(adr_type = C->get_adr_type(adr_idx));
1665   Node *mem = memory(adr_idx);
1666   Node* st = StoreNode::make(_gvn, ctl, mem, adr, adr_type, val, bt, mo, require_atomic_access);
1667   if (unaligned) {
1668     st->as_Store()->set_unaligned_access();
1669   }
1670   if (mismatched) {
1671     st->as_Store()->set_mismatched_access();
1672   }
1673   if (unsafe) {
1674     st->as_Store()->set_unsafe_access();
1675   }
1676   st->as_Store()->set_barrier_data(barrier_data);
1677   st = _gvn.transform(st);
1678   set_memory(st, adr_idx);
1679   // Back-to-back stores can only remove intermediate store with DU info
1680   // so push on worklist for optimizer.
1681   if (mem->req() > MemNode::Address && adr == mem->in(MemNode::Address))
1682     record_for_igvn(st);
1683 
1684   return st;
1685 }
1686 
1687 Node* GraphKit::access_store_at(Node* obj,
1688                                 Node* adr,
1689                                 const TypePtr* adr_type,
1690                                 Node* val,
1691                                 const Type* val_type,
1692                                 BasicType bt,
1693                                 DecoratorSet decorators) {
1694   // Transformation of a value which could be null pointer (CastPP #null)
1695   // could be delayed during Parse (for example, in adjust_map_after_if()).
1696   // Execute transformation here to avoid barrier generation in such case.
1697   if (_gvn.type(val) == TypePtr::NULL_PTR) {
1698     val = _gvn.makecon(TypePtr::NULL_PTR);
1699   }
1700 
1701   if (stopped()) {
1702     return top(); // Dead path ?
1703   }
1704 
1705   assert(val != nullptr, "not dead path");
1706 
1707   C2AccessValuePtr addr(adr, adr_type);
1708   C2AccessValue value(val, val_type);
1709   C2ParseAccess access(this, decorators | C2_WRITE_ACCESS, bt, obj, addr);
1710   if (access.is_raw()) {
1711     return _barrier_set->BarrierSetC2::store_at(access, value);
1712   } else {
1713     return _barrier_set->store_at(access, value);
1714   }
1715 }
1716 
1717 Node* GraphKit::access_load_at(Node* obj,   // containing obj
1718                                Node* adr,   // actual address to store val at
1719                                const TypePtr* adr_type,
1720                                const Type* val_type,
1721                                BasicType bt,
1722                                DecoratorSet decorators) {
1723   if (stopped()) {
1724     return top(); // Dead path ?
1725   }
1726 
1727   SavedState old_state(this);
1728   C2AccessValuePtr addr(adr, adr_type);
1729   C2ParseAccess access(this, decorators | C2_READ_ACCESS, bt, obj, addr);
1730   Node* load;
1731   if (access.is_raw()) {
1732     load = _barrier_set->BarrierSetC2::load_at(access, val_type);
1733   } else {
1734     load = _barrier_set->load_at(access, val_type);
1735   }
1736 
1737   // Restore the previous state only if the load got folded to a constant
1738   // and we can discard any barriers that might have been added.
1739   if (load == nullptr || !load->is_Con()) {
1740     old_state.discard();
1741   }
1742   return load;
1743 }
1744 
1745 Node* GraphKit::access_load(Node* adr,   // actual address to load val at
1746                             const Type* val_type,
1747                             BasicType bt,
1748                             DecoratorSet decorators) {
1749   if (stopped()) {
1750     return top(); // Dead path ?
1751   }
1752 
1753   SavedState old_state(this);
1754   C2AccessValuePtr addr(adr, adr->bottom_type()->is_ptr());
1755   C2ParseAccess access(this, decorators | C2_READ_ACCESS, bt, nullptr, addr);
1756   Node* load;
1757   if (access.is_raw()) {
1758     load = _barrier_set->BarrierSetC2::load_at(access, val_type);
1759   } else {
1760     load = _barrier_set->load_at(access, val_type);
1761   }
1762 
1763   // Restore the previous state only if the load got folded to a constant
1764   // and we can discard any barriers that might have been added.
1765   if (load == nullptr || !load->is_Con()) {
1766     old_state.discard();
1767   }
1768   return load;
1769 }
1770 
1771 Node* GraphKit::access_atomic_cmpxchg_val_at(Node* obj,
1772                                              Node* adr,
1773                                              const TypePtr* adr_type,
1774                                              int alias_idx,
1775                                              Node* expected_val,
1776                                              Node* new_val,
1777                                              const Type* value_type,
1778                                              BasicType bt,
1779                                              DecoratorSet decorators) {
1780   C2AccessValuePtr addr(adr, adr_type);
1781   C2AtomicParseAccess access(this, decorators | C2_READ_ACCESS | C2_WRITE_ACCESS,
1782                         bt, obj, addr, alias_idx);
1783   if (access.is_raw()) {
1784     return _barrier_set->BarrierSetC2::atomic_cmpxchg_val_at(access, expected_val, new_val, value_type);
1785   } else {
1786     return _barrier_set->atomic_cmpxchg_val_at(access, expected_val, new_val, value_type);
1787   }
1788 }
1789 
1790 Node* GraphKit::access_atomic_cmpxchg_bool_at(Node* obj,
1791                                               Node* adr,
1792                                               const TypePtr* adr_type,
1793                                               int alias_idx,
1794                                               Node* expected_val,
1795                                               Node* new_val,
1796                                               const Type* value_type,
1797                                               BasicType bt,
1798                                               DecoratorSet decorators) {
1799   C2AccessValuePtr addr(adr, adr_type);
1800   C2AtomicParseAccess access(this, decorators | C2_READ_ACCESS | C2_WRITE_ACCESS,
1801                         bt, obj, addr, alias_idx);
1802   if (access.is_raw()) {
1803     return _barrier_set->BarrierSetC2::atomic_cmpxchg_bool_at(access, expected_val, new_val, value_type);
1804   } else {
1805     return _barrier_set->atomic_cmpxchg_bool_at(access, expected_val, new_val, value_type);
1806   }
1807 }
1808 
1809 Node* GraphKit::access_atomic_xchg_at(Node* obj,
1810                                       Node* adr,
1811                                       const TypePtr* adr_type,
1812                                       int alias_idx,
1813                                       Node* new_val,
1814                                       const Type* value_type,
1815                                       BasicType bt,
1816                                       DecoratorSet decorators) {
1817   C2AccessValuePtr addr(adr, adr_type);
1818   C2AtomicParseAccess access(this, decorators | C2_READ_ACCESS | C2_WRITE_ACCESS,
1819                         bt, obj, addr, alias_idx);
1820   if (access.is_raw()) {
1821     return _barrier_set->BarrierSetC2::atomic_xchg_at(access, new_val, value_type);
1822   } else {
1823     return _barrier_set->atomic_xchg_at(access, new_val, value_type);
1824   }
1825 }
1826 
1827 Node* GraphKit::access_atomic_add_at(Node* obj,
1828                                      Node* adr,
1829                                      const TypePtr* adr_type,
1830                                      int alias_idx,
1831                                      Node* new_val,
1832                                      const Type* value_type,
1833                                      BasicType bt,
1834                                      DecoratorSet decorators) {
1835   C2AccessValuePtr addr(adr, adr_type);
1836   C2AtomicParseAccess access(this, decorators | C2_READ_ACCESS | C2_WRITE_ACCESS, bt, obj, addr, alias_idx);
1837   if (access.is_raw()) {
1838     return _barrier_set->BarrierSetC2::atomic_add_at(access, new_val, value_type);
1839   } else {
1840     return _barrier_set->atomic_add_at(access, new_val, value_type);
1841   }
1842 }
1843 
1844 void GraphKit::access_clone(Node* src, Node* dst, Node* size, bool is_array) {
1845   return _barrier_set->clone(this, src, dst, size, is_array);
1846 }
1847 
1848 //-------------------------array_element_address-------------------------
1849 Node* GraphKit::array_element_address(Node* ary, Node* idx, BasicType elembt,
1850                                       const TypeInt* sizetype, Node* ctrl) {
1851   uint shift  = exact_log2(type2aelembytes(elembt));
1852   uint header = arrayOopDesc::base_offset_in_bytes(elembt);
1853 
1854   // short-circuit a common case (saves lots of confusing waste motion)
1855   jint idx_con = find_int_con(idx, -1);
1856   if (idx_con >= 0) {
1857     intptr_t offset = header + ((intptr_t)idx_con << shift);
1858     return basic_plus_adr(ary, offset);
1859   }
1860 
1861   // must be correct type for alignment purposes
1862   Node* base  = basic_plus_adr(ary, header);
1863   idx = Compile::conv_I2X_index(&_gvn, idx, sizetype, ctrl);
1864   Node* scale = _gvn.transform( new LShiftXNode(idx, intcon(shift)) );
1865   return basic_plus_adr(ary, base, scale);
1866 }
1867 
1868 //-------------------------load_array_element-------------------------
1869 Node* GraphKit::load_array_element(Node* ary, Node* idx, const TypeAryPtr* arytype, bool set_ctrl) {
1870   const Type* elemtype = arytype->elem();
1871   BasicType elembt = elemtype->array_element_basic_type();
1872   Node* adr = array_element_address(ary, idx, elembt, arytype->size());
1873   if (elembt == T_NARROWOOP) {
1874     elembt = T_OBJECT; // To satisfy switch in LoadNode::make()
1875   }
1876   Node* ld = access_load_at(ary, adr, arytype, elemtype, elembt,
1877                             IN_HEAP | IS_ARRAY | (set_ctrl ? C2_CONTROL_DEPENDENT_LOAD : 0));
1878   return ld;
1879 }
1880 
1881 //-------------------------set_arguments_for_java_call-------------------------
1882 // Arguments (pre-popped from the stack) are taken from the JVMS.
1883 void GraphKit::set_arguments_for_java_call(CallJavaNode* call) {
1884   // Add the call arguments:
1885   uint nargs = call->method()->arg_size();
1886   for (uint i = 0; i < nargs; i++) {
1887     Node* arg = argument(i);
1888     call->init_req(i + TypeFunc::Parms, arg);
1889   }
1890 }
1891 
1892 //---------------------------set_edges_for_java_call---------------------------
1893 // Connect a newly created call into the current JVMS.
1894 // A return value node (if any) is returned from set_edges_for_java_call.
1895 void GraphKit::set_edges_for_java_call(CallJavaNode* call, bool must_throw, bool separate_io_proj) {
1896 
1897   // Add the predefined inputs:
1898   call->init_req( TypeFunc::Control, control() );
1899   call->init_req( TypeFunc::I_O    , i_o() );
1900   call->init_req( TypeFunc::Memory , reset_memory() );
1901   call->init_req( TypeFunc::FramePtr, frameptr() );
1902   call->init_req( TypeFunc::ReturnAdr, top() );
1903 
1904   add_safepoint_edges(call, must_throw);
1905 
1906   Node* xcall = _gvn.transform(call);
1907 
1908   if (xcall == top()) {
1909     set_control(top());
1910     return;
1911   }
1912   assert(xcall == call, "call identity is stable");
1913 
1914   // Re-use the current map to produce the result.
1915 
1916   set_control(_gvn.transform(new ProjNode(call, TypeFunc::Control)));
1917   set_i_o(    _gvn.transform(new ProjNode(call, TypeFunc::I_O    , separate_io_proj)));
1918   set_all_memory_call(xcall, separate_io_proj);
1919 
1920   //return xcall;   // no need, caller already has it
1921 }
1922 
1923 Node* GraphKit::set_results_for_java_call(CallJavaNode* call, bool separate_io_proj, bool deoptimize) {
1924   if (stopped())  return top();  // maybe the call folded up?
1925 
1926   // Capture the return value, if any.
1927   Node* ret;
1928   if (call->method() == nullptr ||
1929       call->method()->return_type()->basic_type() == T_VOID)
1930         ret = top();
1931   else  ret = _gvn.transform(new ProjNode(call, TypeFunc::Parms));
1932 
1933   // Note:  Since any out-of-line call can produce an exception,
1934   // we always insert an I_O projection from the call into the result.
1935 
1936   make_slow_call_ex(call, env()->Throwable_klass(), separate_io_proj, deoptimize);
1937 
1938   if (separate_io_proj) {
1939     // The caller requested separate projections be used by the fall
1940     // through and exceptional paths, so replace the projections for
1941     // the fall through path.
1942     set_i_o(_gvn.transform( new ProjNode(call, TypeFunc::I_O) ));
1943     set_all_memory(_gvn.transform( new ProjNode(call, TypeFunc::Memory) ));
1944   }
1945   return ret;
1946 }
1947 
1948 //--------------------set_predefined_input_for_runtime_call--------------------
1949 // Reading and setting the memory state is way conservative here.
1950 // The real problem is that I am not doing real Type analysis on memory,
1951 // so I cannot distinguish card mark stores from other stores.  Across a GC
1952 // point the Store Barrier and the card mark memory has to agree.  I cannot
1953 // have a card mark store and its barrier split across the GC point from
1954 // either above or below.  Here I get that to happen by reading ALL of memory.
1955 // A better answer would be to separate out card marks from other memory.
1956 // For now, return the input memory state, so that it can be reused
1957 // after the call, if this call has restricted memory effects.
1958 Node* GraphKit::set_predefined_input_for_runtime_call(SafePointNode* call, Node* narrow_mem) {
1959   // Set fixed predefined input arguments
1960   call->init_req(TypeFunc::Control, control());
1961   call->init_req(TypeFunc::I_O, top()); // does no i/o
1962   call->init_req(TypeFunc::ReturnAdr, top());
1963   if (call->is_CallLeafPure()) {
1964     call->init_req(TypeFunc::Memory, top());
1965     call->init_req(TypeFunc::FramePtr, top());
1966     return nullptr;
1967   } else {
1968     Node* memory = reset_memory();
1969     Node* m = narrow_mem == nullptr ? memory : narrow_mem;
1970     call->init_req(TypeFunc::Memory, m); // may gc ptrs
1971     call->init_req(TypeFunc::FramePtr, frameptr());
1972     return memory;
1973   }
1974 }
1975 
1976 //-------------------set_predefined_output_for_runtime_call--------------------
1977 // Set control and memory (not i_o) from the call.
1978 // If keep_mem is not null, use it for the output state,
1979 // except for the RawPtr output of the call, if hook_mem is TypeRawPtr::BOTTOM.
1980 // If hook_mem is null, this call produces no memory effects at all.
1981 // If hook_mem is a Java-visible memory slice (such as arraycopy operands),
1982 // then only that memory slice is taken from the call.
1983 // In the last case, we must put an appropriate memory barrier before
1984 // the call, so as to create the correct anti-dependencies on loads
1985 // preceding the call.
1986 void GraphKit::set_predefined_output_for_runtime_call(Node* call,
1987                                                       Node* keep_mem,
1988                                                       const TypePtr* hook_mem) {
1989   // no i/o
1990   set_control(_gvn.transform( new ProjNode(call,TypeFunc::Control) ));
1991   if (call->is_CallLeafPure()) {
1992     // Pure function have only control (for now) and data output, in particular
1993     // they don't touch the memory, so we don't want a memory proj that is set after.
1994     return;
1995   }
1996   if (keep_mem) {
1997     // First clone the existing memory state
1998     set_all_memory(keep_mem);
1999     if (hook_mem != nullptr) {
2000       // Make memory for the call
2001       Node* mem = _gvn.transform( new ProjNode(call, TypeFunc::Memory) );
2002       // Set the RawPtr memory state only.  This covers all the heap top/GC stuff
2003       // We also use hook_mem to extract specific effects from arraycopy stubs.
2004       set_memory(mem, hook_mem);
2005     }
2006     // ...else the call has NO memory effects.
2007 
2008     // Make sure the call advertises its memory effects precisely.
2009     // This lets us build accurate anti-dependences in gcm.cpp.
2010     assert(C->alias_type(call->adr_type()) == C->alias_type(hook_mem),
2011            "call node must be constructed correctly");
2012   } else {
2013     assert(hook_mem == nullptr, "");
2014     // This is not a "slow path" call; all memory comes from the call.
2015     set_all_memory_call(call);
2016   }
2017 }
2018 
2019 // Keep track of MergeMems feeding into other MergeMems
2020 static void add_mergemem_users_to_worklist(Unique_Node_List& wl, Node* mem) {
2021   if (!mem->is_MergeMem()) {
2022     return;
2023   }
2024   for (SimpleDUIterator i(mem); i.has_next(); i.next()) {
2025     Node* use = i.get();
2026     if (use->is_MergeMem()) {
2027       wl.push(use);
2028     }
2029   }
2030 }
2031 
2032 // Replace the call with the current state of the kit.
2033 void GraphKit::replace_call(CallNode* call, Node* result, bool do_replaced_nodes, bool do_asserts) {
2034   JVMState* ejvms = nullptr;
2035   if (has_exceptions()) {
2036     ejvms = transfer_exceptions_into_jvms();
2037   }
2038 
2039   ReplacedNodes replaced_nodes = map()->replaced_nodes();
2040   ReplacedNodes replaced_nodes_exception;
2041   Node* ex_ctl = top();
2042 
2043   SafePointNode* final_state = stop();
2044 
2045   // Find all the needed outputs of this call
2046   CallProjections callprojs;
2047   call->extract_projections(&callprojs, true, do_asserts);
2048 
2049   Unique_Node_List wl;
2050   Node* init_mem = call->in(TypeFunc::Memory);
2051   Node* final_mem = final_state->in(TypeFunc::Memory);
2052   Node* final_ctl = final_state->in(TypeFunc::Control);
2053   Node* final_io = final_state->in(TypeFunc::I_O);
2054 
2055   // Replace all the old call edges with the edges from the inlining result
2056   if (callprojs.fallthrough_catchproj != nullptr) {
2057     C->gvn_replace_by(callprojs.fallthrough_catchproj, final_ctl);
2058   }
2059   if (callprojs.fallthrough_memproj != nullptr) {
2060     if (final_mem->is_MergeMem()) {
2061       // Parser's exits MergeMem was not transformed but may be optimized
2062       final_mem = _gvn.transform(final_mem);
2063     }
2064     C->gvn_replace_by(callprojs.fallthrough_memproj,   final_mem);
2065     add_mergemem_users_to_worklist(wl, final_mem);
2066   }
2067   if (callprojs.fallthrough_ioproj != nullptr) {
2068     C->gvn_replace_by(callprojs.fallthrough_ioproj,    final_io);
2069   }
2070 
2071   // Replace the result with the new result if it exists and is used
2072   if (callprojs.resproj != nullptr && result != nullptr) {
2073     C->gvn_replace_by(callprojs.resproj, result);
2074   }
2075 
2076   if (ejvms == nullptr) {
2077     // No exception edges to simply kill off those paths
2078     if (callprojs.catchall_catchproj != nullptr) {
2079       C->gvn_replace_by(callprojs.catchall_catchproj, C->top());
2080     }
2081     if (callprojs.catchall_memproj != nullptr) {
2082       C->gvn_replace_by(callprojs.catchall_memproj,   C->top());
2083     }
2084     if (callprojs.catchall_ioproj != nullptr) {
2085       C->gvn_replace_by(callprojs.catchall_ioproj,    C->top());
2086     }
2087     // Replace the old exception object with top
2088     if (callprojs.exobj != nullptr) {
2089       C->gvn_replace_by(callprojs.exobj, C->top());
2090     }
2091   } else {
2092     GraphKit ekit(ejvms);
2093 
2094     // Load my combined exception state into the kit, with all phis transformed:
2095     SafePointNode* ex_map = ekit.combine_and_pop_all_exception_states();
2096     replaced_nodes_exception = ex_map->replaced_nodes();
2097 
2098     Node* ex_oop = ekit.use_exception_state(ex_map);
2099 
2100     if (callprojs.catchall_catchproj != nullptr) {
2101       C->gvn_replace_by(callprojs.catchall_catchproj, ekit.control());
2102       ex_ctl = ekit.control();
2103     }
2104     if (callprojs.catchall_memproj != nullptr) {
2105       Node* ex_mem = ekit.reset_memory();
2106       C->gvn_replace_by(callprojs.catchall_memproj,   ex_mem);
2107       add_mergemem_users_to_worklist(wl, ex_mem);
2108     }
2109     if (callprojs.catchall_ioproj != nullptr) {
2110       C->gvn_replace_by(callprojs.catchall_ioproj,    ekit.i_o());
2111     }
2112 
2113     // Replace the old exception object with the newly created one
2114     if (callprojs.exobj != nullptr) {
2115       C->gvn_replace_by(callprojs.exobj, ex_oop);
2116     }
2117   }
2118 
2119   // Disconnect the call from the graph
2120   call->disconnect_inputs(C);
2121   C->gvn_replace_by(call, C->top());
2122 
2123   // Clean up any MergeMems that feed other MergeMems since the
2124   // optimizer doesn't like that.
2125   while (wl.size() > 0) {
2126     _gvn.transform(wl.pop());
2127   }
2128 
2129   if (callprojs.fallthrough_catchproj != nullptr && !final_ctl->is_top() && do_replaced_nodes) {
2130     replaced_nodes.apply(C, final_ctl);
2131   }
2132   if (!ex_ctl->is_top() && do_replaced_nodes) {
2133     replaced_nodes_exception.apply(C, ex_ctl);
2134   }
2135 }
2136 
2137 
2138 //------------------------------increment_counter------------------------------
2139 // for statistics: increment a VM counter by 1
2140 
2141 void GraphKit::increment_counter(address counter_addr) {
2142   Node* adr1 = makecon(TypeRawPtr::make(counter_addr));
2143   increment_counter(adr1);
2144 }
2145 
2146 void GraphKit::increment_counter(Node* counter_addr) {
2147   Node* ctrl = control();
2148   Node* cnt  = make_load(ctrl, counter_addr, TypeLong::LONG, T_LONG, MemNode::unordered);
2149   Node* incr = _gvn.transform(new AddLNode(cnt, _gvn.longcon(1)));
2150   store_to_memory(ctrl, counter_addr, incr, T_LONG, MemNode::unordered);
2151 }
2152 
2153 void GraphKit::halt(Node* ctrl, Node* frameptr, const char* reason, bool generate_code_in_product) {
2154   Node* halt = new HaltNode(ctrl, frameptr, reason
2155                             PRODUCT_ONLY(COMMA generate_code_in_product));
2156   halt = _gvn.transform(halt);
2157   root()->add_req(halt);
2158 }
2159 
2160 //------------------------------uncommon_trap----------------------------------
2161 // Bail out to the interpreter in mid-method.  Implemented by calling the
2162 // uncommon_trap blob.  This helper function inserts a runtime call with the
2163 // right debug info.
2164 Node* GraphKit::uncommon_trap(int trap_request,
2165                              ciKlass* klass, const char* comment,
2166                              bool must_throw,
2167                              bool keep_exact_action) {
2168   if (failing_internal()) {
2169     stop();
2170   }
2171   if (stopped())  return nullptr; // trap reachable?
2172 
2173   // Note:  If ProfileTraps is true, and if a deopt. actually
2174   // occurs here, the runtime will make sure an MDO exists.  There is
2175   // no need to call method()->ensure_method_data() at this point.
2176 
2177   // Set the stack pointer to the right value for reexecution:
2178   set_sp(reexecute_sp());
2179 
2180 #ifdef ASSERT
2181   if (!must_throw) {
2182     // Make sure the stack has at least enough depth to execute
2183     // the current bytecode.
2184     int inputs, ignored_depth;
2185     if (compute_stack_effects(inputs, ignored_depth)) {
2186       assert(sp() >= inputs, "must have enough JVMS stack to execute %s: sp=%d, inputs=%d",
2187              Bytecodes::name(java_bc()), sp(), inputs);
2188     }
2189   }
2190 #endif
2191 
2192   Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(trap_request);
2193   Deoptimization::DeoptAction action = Deoptimization::trap_request_action(trap_request);
2194 
2195   switch (action) {
2196   case Deoptimization::Action_maybe_recompile:
2197   case Deoptimization::Action_reinterpret:
2198     // Temporary fix for 6529811 to allow virtual calls to be sure they
2199     // get the chance to go from mono->bi->mega
2200     if (!keep_exact_action &&
2201         Deoptimization::trap_request_index(trap_request) < 0 &&
2202         too_many_recompiles(reason)) {
2203       // This BCI is causing too many recompilations.
2204       if (C->log() != nullptr) {
2205         C->log()->elem("observe that='trap_action_change' reason='%s' from='%s' to='none'",
2206                 Deoptimization::trap_reason_name(reason),
2207                 Deoptimization::trap_action_name(action));
2208       }
2209       action = Deoptimization::Action_none;
2210       trap_request = Deoptimization::make_trap_request(reason, action);
2211     } else {
2212       C->set_trap_can_recompile(true);
2213     }
2214     break;
2215   case Deoptimization::Action_make_not_entrant:
2216     C->set_trap_can_recompile(true);
2217     break;
2218   case Deoptimization::Action_none:
2219   case Deoptimization::Action_make_not_compilable:
2220     break;
2221   default:
2222 #ifdef ASSERT
2223     fatal("unknown action %d: %s", action, Deoptimization::trap_action_name(action));
2224 #endif
2225     break;
2226   }
2227 
2228   if (TraceOptoParse) {
2229     char buf[100];
2230     tty->print_cr("Uncommon trap %s at bci:%d",
2231                   Deoptimization::format_trap_request(buf, sizeof(buf),
2232                                                       trap_request), bci());
2233   }
2234 
2235   CompileLog* log = C->log();
2236   if (log != nullptr) {
2237     int kid = (klass == nullptr)? -1: log->identify(klass);
2238     log->begin_elem("uncommon_trap bci='%d'", bci());
2239     char buf[100];
2240     log->print(" %s", Deoptimization::format_trap_request(buf, sizeof(buf),
2241                                                           trap_request));
2242     if (kid >= 0)         log->print(" klass='%d'", kid);
2243     if (comment != nullptr)  log->print(" comment='%s'", comment);
2244     log->end_elem();
2245   }
2246 
2247   // Make sure any guarding test views this path as very unlikely
2248   Node *i0 = control()->in(0);
2249   if (i0 != nullptr && i0->is_If()) {        // Found a guarding if test?
2250     IfNode *iff = i0->as_If();
2251     float f = iff->_prob;   // Get prob
2252     if (control()->Opcode() == Op_IfTrue) {
2253       if (f > PROB_UNLIKELY_MAG(4))
2254         iff->_prob = PROB_MIN;
2255     } else {
2256       if (f < PROB_LIKELY_MAG(4))
2257         iff->_prob = PROB_MAX;
2258     }
2259   }
2260 
2261   // Clear out dead values from the debug info.
2262   kill_dead_locals();
2263 
2264   // Now insert the uncommon trap subroutine call
2265   address call_addr = OptoRuntime::uncommon_trap_blob()->entry_point();
2266   const TypePtr* no_memory_effects = nullptr;
2267   // Pass the index of the class to be loaded
2268   Node* call = make_runtime_call(RC_NO_LEAF | RC_UNCOMMON |
2269                                  (must_throw ? RC_MUST_THROW : 0),
2270                                  OptoRuntime::uncommon_trap_Type(),
2271                                  call_addr, "uncommon_trap", no_memory_effects,
2272                                  intcon(trap_request));
2273   assert(call->as_CallStaticJava()->uncommon_trap_request() == trap_request,
2274          "must extract request correctly from the graph");
2275   assert(trap_request != 0, "zero value reserved by uncommon_trap_request");
2276 
2277   call->set_req(TypeFunc::ReturnAdr, returnadr());
2278   // The debug info is the only real input to this call.
2279 
2280   // Halt-and-catch fire here.  The above call should never return!
2281   // We only emit code for the HaltNode in debug, which is enough for
2282   // verifying correctness. In product, we don't want to emit it so
2283   // that we can save on code space. HaltNode often get folded because
2284   // the compiler can prove that the unreachable path is dead. But we
2285   // cannot generally expect that for uncommon traps, which are often
2286   // reachable and occasionally taken.
2287   halt(control(), frameptr(),
2288        "uncommon trap returned which should never happen",
2289        false /* don't emit code in product */);
2290   stop_and_kill_map();
2291   return call;
2292 }
2293 
2294 
2295 //--------------------------just_allocated_object------------------------------
2296 // Report the object that was just allocated.
2297 // It must be the case that there are no intervening safepoints.
2298 // We use this to determine if an object is so "fresh" that
2299 // it does not require card marks.
2300 Node* GraphKit::just_allocated_object(Node* current_control) {
2301   Node* ctrl = current_control;
2302   // Object::<init> is invoked after allocation, most of invoke nodes
2303   // will be reduced, but a region node is kept in parse time, we check
2304   // the pattern and skip the region node if it degraded to a copy.
2305   if (ctrl != nullptr && ctrl->is_Region() && ctrl->req() == 2 &&
2306       ctrl->as_Region()->is_copy()) {
2307     ctrl = ctrl->as_Region()->is_copy();
2308   }
2309   if (C->recent_alloc_ctl() == ctrl) {
2310    return C->recent_alloc_obj();
2311   }
2312   return nullptr;
2313 }
2314 
2315 
2316 /**
2317  * Record profiling data exact_kls for Node n with the type system so
2318  * that it can propagate it (speculation)
2319  *
2320  * @param n          node that the type applies to
2321  * @param exact_kls  type from profiling
2322  * @param maybe_null did profiling see null?
2323  *
2324  * @return           node with improved type
2325  */
2326 Node* GraphKit::record_profile_for_speculation(Node* n, ciKlass* exact_kls, ProfilePtrKind ptr_kind) {
2327   const Type* current_type = _gvn.type(n);
2328   assert(UseTypeSpeculation, "type speculation must be on");
2329 
2330   const TypePtr* speculative = current_type->speculative();
2331 
2332   // Should the klass from the profile be recorded in the speculative type?
2333   if (current_type->would_improve_type(exact_kls, jvms()->depth())) {
2334     const TypeKlassPtr* tklass = TypeKlassPtr::make(exact_kls, Type::trust_interfaces);
2335     const TypeOopPtr* xtype = tklass->as_instance_type();
2336     assert(xtype->klass_is_exact(), "Should be exact");
2337     // Any reason to believe n is not null (from this profiling or a previous one)?
2338     assert(ptr_kind != ProfileAlwaysNull, "impossible here");
2339     const TypePtr* ptr = (ptr_kind == ProfileMaybeNull && current_type->speculative_maybe_null()) ? TypePtr::BOTTOM : TypePtr::NOTNULL;
2340     // record the new speculative type's depth
2341     speculative = xtype->cast_to_ptr_type(ptr->ptr())->is_ptr();
2342     speculative = speculative->with_inline_depth(jvms()->depth());
2343   } else if (current_type->would_improve_ptr(ptr_kind)) {
2344     // Profiling report that null was never seen so we can change the
2345     // speculative type to non null ptr.
2346     if (ptr_kind == ProfileAlwaysNull) {
2347       speculative = TypePtr::NULL_PTR;
2348     } else {
2349       assert(ptr_kind == ProfileNeverNull, "nothing else is an improvement");
2350       const TypePtr* ptr = TypePtr::NOTNULL;
2351       if (speculative != nullptr) {
2352         speculative = speculative->cast_to_ptr_type(ptr->ptr())->is_ptr();
2353       } else {
2354         speculative = ptr;
2355       }
2356     }
2357   }
2358 
2359   if (speculative != current_type->speculative()) {
2360     // Build a type with a speculative type (what we think we know
2361     // about the type but will need a guard when we use it)
2362     const TypeOopPtr* spec_type = TypeOopPtr::make(TypePtr::BotPTR, Type::OffsetBot, TypeOopPtr::InstanceBot, speculative);
2363     // We're changing the type, we need a new CheckCast node to carry
2364     // the new type. The new type depends on the control: what
2365     // profiling tells us is only valid from here as far as we can
2366     // tell.
2367     Node* cast = new CheckCastPPNode(control(), n, current_type->remove_speculative()->join_speculative(spec_type));
2368     cast = _gvn.transform(cast);
2369     replace_in_map(n, cast);
2370     n = cast;
2371   }
2372 
2373   return n;
2374 }
2375 
2376 /**
2377  * Record profiling data from receiver profiling at an invoke with the
2378  * type system so that it can propagate it (speculation)
2379  *
2380  * @param n  receiver node
2381  *
2382  * @return   node with improved type
2383  */
2384 Node* GraphKit::record_profiled_receiver_for_speculation(Node* n) {
2385   if (!UseTypeSpeculation) {
2386     return n;
2387   }
2388   ciKlass* exact_kls = profile_has_unique_klass();
2389   ProfilePtrKind ptr_kind = ProfileMaybeNull;
2390   if ((java_bc() == Bytecodes::_checkcast ||
2391        java_bc() == Bytecodes::_instanceof ||
2392        java_bc() == Bytecodes::_aastore) &&
2393       method()->method_data()->is_mature()) {
2394     ciProfileData* data = method()->method_data()->bci_to_data(bci());
2395     if (data != nullptr) {
2396       if (!data->as_BitData()->null_seen()) {
2397         ptr_kind = ProfileNeverNull;
2398       } else {
2399         if (TypeProfileCasts) {
2400           assert(data->is_ReceiverTypeData(), "bad profile data type");
2401           ciReceiverTypeData* call = (ciReceiverTypeData*)data->as_ReceiverTypeData();
2402           uint i = 0;
2403           for (; i < call->row_limit(); i++) {
2404             ciKlass* receiver = call->receiver(i);
2405             if (receiver != nullptr) {
2406               break;
2407             }
2408           }
2409           ptr_kind = (i == call->row_limit()) ? ProfileAlwaysNull : ProfileMaybeNull;
2410         }
2411       }
2412     }
2413   }
2414   return record_profile_for_speculation(n, exact_kls, ptr_kind);
2415 }
2416 
2417 /**
2418  * Record profiling data from argument profiling at an invoke with the
2419  * type system so that it can propagate it (speculation)
2420  *
2421  * @param dest_method  target method for the call
2422  * @param bc           what invoke bytecode is this?
2423  */
2424 void GraphKit::record_profiled_arguments_for_speculation(ciMethod* dest_method, Bytecodes::Code bc) {
2425   if (!UseTypeSpeculation) {
2426     return;
2427   }
2428   const TypeFunc* tf    = TypeFunc::make(dest_method);
2429   int             nargs = tf->domain()->cnt() - TypeFunc::Parms;
2430   int skip = Bytecodes::has_receiver(bc) ? 1 : 0;
2431   for (int j = skip, i = 0; j < nargs && i < TypeProfileArgsLimit; j++) {
2432     const Type *targ = tf->domain()->field_at(j + TypeFunc::Parms);
2433     if (is_reference_type(targ->basic_type())) {
2434       ProfilePtrKind ptr_kind = ProfileMaybeNull;
2435       ciKlass* better_type = nullptr;
2436       if (method()->argument_profiled_type(bci(), i, better_type, ptr_kind)) {
2437         record_profile_for_speculation(argument(j), better_type, ptr_kind);
2438       }
2439       i++;
2440     }
2441   }
2442 }
2443 
2444 /**
2445  * Record profiling data from parameter profiling at an invoke with
2446  * the type system so that it can propagate it (speculation)
2447  */
2448 void GraphKit::record_profiled_parameters_for_speculation() {
2449   if (!UseTypeSpeculation) {
2450     return;
2451   }
2452   for (int i = 0, j = 0; i < method()->arg_size() ; i++) {
2453     if (_gvn.type(local(i))->isa_oopptr()) {
2454       ProfilePtrKind ptr_kind = ProfileMaybeNull;
2455       ciKlass* better_type = nullptr;
2456       if (method()->parameter_profiled_type(j, better_type, ptr_kind)) {
2457         record_profile_for_speculation(local(i), better_type, ptr_kind);
2458       }
2459       j++;
2460     }
2461   }
2462 }
2463 
2464 /**
2465  * Record profiling data from return value profiling at an invoke with
2466  * the type system so that it can propagate it (speculation)
2467  */
2468 void GraphKit::record_profiled_return_for_speculation() {
2469   if (!UseTypeSpeculation) {
2470     return;
2471   }
2472   ProfilePtrKind ptr_kind = ProfileMaybeNull;
2473   ciKlass* better_type = nullptr;
2474   if (method()->return_profiled_type(bci(), better_type, ptr_kind)) {
2475     // If profiling reports a single type for the return value,
2476     // feed it to the type system so it can propagate it as a
2477     // speculative type
2478     record_profile_for_speculation(stack(sp()-1), better_type, ptr_kind);
2479   }
2480 }
2481 
2482 
2483 //=============================================================================
2484 // Generate a fast path/slow path idiom.  Graph looks like:
2485 // [foo] indicates that 'foo' is a parameter
2486 //
2487 //              [in]     null
2488 //                 \    /
2489 //                  CmpP
2490 //                  Bool ne
2491 //                   If
2492 //                  /  \
2493 //              True    False-<2>
2494 //              / |
2495 //             /  cast_not_null
2496 //           Load  |    |   ^
2497 //        [fast_test]   |   |
2498 // gvn to   opt_test    |   |
2499 //          /    \      |  <1>
2500 //      True     False  |
2501 //        |         \\  |
2502 //   [slow_call]     \[fast_result]
2503 //    Ctl   Val       \      \
2504 //     |               \      \
2505 //    Catch       <1>   \      \
2506 //   /    \        ^     \      \
2507 //  Ex    No_Ex    |      \      \
2508 //  |       \   \  |       \ <2>  \
2509 //  ...      \  [slow_res] |  |    \   [null_result]
2510 //            \         \--+--+---  |  |
2511 //             \           | /    \ | /
2512 //              --------Region     Phi
2513 //
2514 //=============================================================================
2515 // Code is structured as a series of driver functions all called 'do_XXX' that
2516 // call a set of helper functions.  Helper functions first, then drivers.
2517 
2518 //------------------------------null_check_oop---------------------------------
2519 // Null check oop.  Set null-path control into Region in slot 3.
2520 // Make a cast-not-nullness use the other not-null control.  Return cast.
2521 Node* GraphKit::null_check_oop(Node* value, Node* *null_control,
2522                                bool never_see_null,
2523                                bool safe_for_replace,
2524                                bool speculative) {
2525   // Initial null check taken path
2526   (*null_control) = top();
2527   Node* cast = null_check_common(value, T_OBJECT, false, null_control, speculative);
2528 
2529   // Generate uncommon_trap:
2530   if (never_see_null && (*null_control) != top()) {
2531     // If we see an unexpected null at a check-cast we record it and force a
2532     // recompile; the offending check-cast will be compiled to handle nulls.
2533     // If we see more than one offending BCI, then all checkcasts in the
2534     // method will be compiled to handle nulls.
2535     PreserveJVMState pjvms(this);
2536     set_control(*null_control);
2537     replace_in_map(value, null());
2538     Deoptimization::DeoptReason reason = Deoptimization::reason_null_check(speculative);
2539     uncommon_trap(reason,
2540                   Deoptimization::Action_make_not_entrant);
2541     (*null_control) = top();    // null path is dead
2542   }
2543   if ((*null_control) == top() && safe_for_replace) {
2544     replace_in_map(value, cast);
2545   }
2546 
2547   // Cast away null-ness on the result
2548   return cast;
2549 }
2550 
2551 //------------------------------opt_iff----------------------------------------
2552 // Optimize the fast-check IfNode.  Set the fast-path region slot 2.
2553 // Return slow-path control.
2554 Node* GraphKit::opt_iff(Node* region, Node* iff) {
2555   IfNode *opt_iff = _gvn.transform(iff)->as_If();
2556 
2557   // Fast path taken; set region slot 2
2558   Node *fast_taken = _gvn.transform( new IfFalseNode(opt_iff) );
2559   region->init_req(2,fast_taken); // Capture fast-control
2560 
2561   // Fast path not-taken, i.e. slow path
2562   Node *slow_taken = _gvn.transform( new IfTrueNode(opt_iff) );
2563   return slow_taken;
2564 }
2565 
2566 //-----------------------------make_runtime_call-------------------------------
2567 Node* GraphKit::make_runtime_call(int flags,
2568                                   const TypeFunc* call_type, address call_addr,
2569                                   const char* call_name,
2570                                   const TypePtr* adr_type,
2571                                   // The following parms are all optional.
2572                                   // The first null ends the list.
2573                                   Node* parm0, Node* parm1,
2574                                   Node* parm2, Node* parm3,
2575                                   Node* parm4, Node* parm5,
2576                                   Node* parm6, Node* parm7) {
2577   assert(call_addr != nullptr, "must not call null targets");
2578 
2579   // Slow-path call
2580   bool is_leaf = !(flags & RC_NO_LEAF);
2581   bool has_io  = (!is_leaf && !(flags & RC_NO_IO));
2582   if (call_name == nullptr) {
2583     assert(!is_leaf, "must supply name for leaf");
2584     call_name = OptoRuntime::stub_name(call_addr);
2585   }
2586   CallNode* call;
2587   if (!is_leaf) {
2588     call = new CallStaticJavaNode(call_type, call_addr, call_name, adr_type);
2589   } else if (flags & RC_NO_FP) {
2590     call = new CallLeafNoFPNode(call_type, call_addr, call_name, adr_type);
2591   } else  if (flags & RC_VECTOR){
2592     uint num_bits = call_type->range()->field_at(TypeFunc::Parms)->is_vect()->length_in_bytes() * BitsPerByte;
2593     call = new CallLeafVectorNode(call_type, call_addr, call_name, adr_type, num_bits);
2594   } else if (flags & RC_PURE) {
2595     assert(adr_type == nullptr, "pure call does not touch memory");
2596     call = new CallLeafPureNode(call_type, call_addr, call_name);
2597   } else {
2598     call = new CallLeafNode(call_type, call_addr, call_name, adr_type);
2599   }
2600 
2601   // The following is similar to set_edges_for_java_call,
2602   // except that the memory effects of the call are restricted to AliasIdxRaw.
2603 
2604   // Slow path call has no side-effects, uses few values
2605   bool wide_in  = !(flags & RC_NARROW_MEM);
2606   bool wide_out = (C->get_alias_index(adr_type) == Compile::AliasIdxBot);
2607 
2608   Node* prev_mem = nullptr;
2609   if (wide_in) {
2610     prev_mem = set_predefined_input_for_runtime_call(call);
2611   } else {
2612     assert(!wide_out, "narrow in => narrow out");
2613     Node* narrow_mem = memory(adr_type);
2614     prev_mem = set_predefined_input_for_runtime_call(call, narrow_mem);
2615   }
2616 
2617   // Hook each parm in order.  Stop looking at the first null.
2618   if (parm0 != nullptr) { call->init_req(TypeFunc::Parms+0, parm0);
2619   if (parm1 != nullptr) { call->init_req(TypeFunc::Parms+1, parm1);
2620   if (parm2 != nullptr) { call->init_req(TypeFunc::Parms+2, parm2);
2621   if (parm3 != nullptr) { call->init_req(TypeFunc::Parms+3, parm3);
2622   if (parm4 != nullptr) { call->init_req(TypeFunc::Parms+4, parm4);
2623   if (parm5 != nullptr) { call->init_req(TypeFunc::Parms+5, parm5);
2624   if (parm6 != nullptr) { call->init_req(TypeFunc::Parms+6, parm6);
2625   if (parm7 != nullptr) { call->init_req(TypeFunc::Parms+7, parm7);
2626   /* close each nested if ===> */  } } } } } } } }
2627   assert(call->in(call->req()-1) != nullptr, "must initialize all parms");
2628 
2629   if (!is_leaf) {
2630     // Non-leaves can block and take safepoints:
2631     add_safepoint_edges(call, ((flags & RC_MUST_THROW) != 0));
2632   }
2633   // Non-leaves can throw exceptions:
2634   if (has_io) {
2635     call->set_req(TypeFunc::I_O, i_o());
2636   }
2637 
2638   if (flags & RC_UNCOMMON) {
2639     // Set the count to a tiny probability.  Cf. Estimate_Block_Frequency.
2640     // (An "if" probability corresponds roughly to an unconditional count.
2641     // Sort of.)
2642     call->set_cnt(PROB_UNLIKELY_MAG(4));
2643   }
2644 
2645   Node* c = _gvn.transform(call);
2646   assert(c == call, "cannot disappear");
2647 
2648   if (wide_out) {
2649     // Slow path call has full side-effects.
2650     set_predefined_output_for_runtime_call(call);
2651   } else {
2652     // Slow path call has few side-effects, and/or sets few values.
2653     set_predefined_output_for_runtime_call(call, prev_mem, adr_type);
2654   }
2655 
2656   if (has_io) {
2657     set_i_o(_gvn.transform(new ProjNode(call, TypeFunc::I_O)));
2658   }
2659   return call;
2660 
2661 }
2662 
2663 // i2b
2664 Node* GraphKit::sign_extend_byte(Node* in) {
2665   Node* tmp = _gvn.transform(new LShiftINode(in, _gvn.intcon(24)));
2666   return _gvn.transform(new RShiftINode(tmp, _gvn.intcon(24)));
2667 }
2668 
2669 // i2s
2670 Node* GraphKit::sign_extend_short(Node* in) {
2671   Node* tmp = _gvn.transform(new LShiftINode(in, _gvn.intcon(16)));
2672   return _gvn.transform(new RShiftINode(tmp, _gvn.intcon(16)));
2673 }
2674 
2675 //------------------------------merge_memory-----------------------------------
2676 // Merge memory from one path into the current memory state.
2677 void GraphKit::merge_memory(Node* new_mem, Node* region, int new_path) {
2678   for (MergeMemStream mms(merged_memory(), new_mem->as_MergeMem()); mms.next_non_empty2(); ) {
2679     Node* old_slice = mms.force_memory();
2680     Node* new_slice = mms.memory2();
2681     if (old_slice != new_slice) {
2682       PhiNode* phi;
2683       if (old_slice->is_Phi() && old_slice->as_Phi()->region() == region) {
2684         if (mms.is_empty()) {
2685           // clone base memory Phi's inputs for this memory slice
2686           assert(old_slice == mms.base_memory(), "sanity");
2687           phi = PhiNode::make(region, nullptr, Type::MEMORY, mms.adr_type(C));
2688           _gvn.set_type(phi, Type::MEMORY);
2689           for (uint i = 1; i < phi->req(); i++) {
2690             phi->init_req(i, old_slice->in(i));
2691           }
2692         } else {
2693           phi = old_slice->as_Phi(); // Phi was generated already
2694         }
2695       } else {
2696         phi = PhiNode::make(region, old_slice, Type::MEMORY, mms.adr_type(C));
2697         _gvn.set_type(phi, Type::MEMORY);
2698       }
2699       phi->set_req(new_path, new_slice);
2700       mms.set_memory(phi);
2701     }
2702   }
2703 }
2704 
2705 //------------------------------make_slow_call_ex------------------------------
2706 // Make the exception handler hookups for the slow call
2707 void GraphKit::make_slow_call_ex(Node* call, ciInstanceKlass* ex_klass, bool separate_io_proj, bool deoptimize) {
2708   if (stopped())  return;
2709 
2710   // Make a catch node with just two handlers:  fall-through and catch-all
2711   Node* i_o  = _gvn.transform( new ProjNode(call, TypeFunc::I_O, separate_io_proj) );
2712   Node* catc = _gvn.transform( new CatchNode(control(), i_o, 2) );
2713   Node* norm = new CatchProjNode(catc, CatchProjNode::fall_through_index, CatchProjNode::no_handler_bci);
2714   _gvn.set_type_bottom(norm);
2715   C->record_for_igvn(norm);
2716   Node* excp = _gvn.transform( new CatchProjNode(catc, CatchProjNode::catch_all_index,    CatchProjNode::no_handler_bci) );
2717 
2718   { PreserveJVMState pjvms(this);
2719     set_control(excp);
2720     set_i_o(i_o);
2721 
2722     if (excp != top()) {
2723       if (deoptimize) {
2724         // Deoptimize if an exception is caught. Don't construct exception state in this case.
2725         uncommon_trap(Deoptimization::Reason_unhandled,
2726                       Deoptimization::Action_none);
2727       } else {
2728         // Create an exception state also.
2729         // Use an exact type if the caller has a specific exception.
2730         const Type* ex_type = TypeOopPtr::make_from_klass_unique(ex_klass)->cast_to_ptr_type(TypePtr::NotNull);
2731         Node*       ex_oop  = new CreateExNode(ex_type, control(), i_o);
2732         add_exception_state(make_exception_state(_gvn.transform(ex_oop)));
2733       }
2734     }
2735   }
2736 
2737   // Get the no-exception control from the CatchNode.
2738   set_control(norm);
2739 }
2740 
2741 static IfNode* gen_subtype_check_compare(Node* ctrl, Node* in1, Node* in2, BoolTest::mask test, float p, PhaseGVN& gvn, BasicType bt) {
2742   Node* cmp = nullptr;
2743   switch(bt) {
2744   case T_INT: cmp = new CmpINode(in1, in2); break;
2745   case T_ADDRESS: cmp = new CmpPNode(in1, in2); break;
2746   default: fatal("unexpected comparison type %s", type2name(bt));
2747   }
2748   cmp = gvn.transform(cmp);
2749   Node* bol = gvn.transform(new BoolNode(cmp, test));
2750   IfNode* iff = new IfNode(ctrl, bol, p, COUNT_UNKNOWN);
2751   gvn.transform(iff);
2752   if (!bol->is_Con()) gvn.record_for_igvn(iff);
2753   return iff;
2754 }
2755 
2756 //-------------------------------gen_subtype_check-----------------------------
2757 // Generate a subtyping check.  Takes as input the subtype and supertype.
2758 // Returns 2 values: sets the default control() to the true path and returns
2759 // the false path.  Only reads invariant memory; sets no (visible) memory.
2760 // The PartialSubtypeCheckNode sets the hidden 1-word cache in the encoding
2761 // but that's not exposed to the optimizer.  This call also doesn't take in an
2762 // Object; if you wish to check an Object you need to load the Object's class
2763 // prior to coming here.
2764 Node* Phase::gen_subtype_check(Node* subklass, Node* superklass, Node** ctrl, Node* mem, PhaseGVN& gvn,
2765                                ciMethod* method, int bci) {
2766   Compile* C = gvn.C;
2767   if ((*ctrl)->is_top()) {
2768     return C->top();
2769   }
2770 
2771   // Fast check for identical types, perhaps identical constants.
2772   // The types can even be identical non-constants, in cases
2773   // involving Array.newInstance, Object.clone, etc.
2774   if (subklass == superklass)
2775     return C->top();             // false path is dead; no test needed.
2776 
2777   if (gvn.type(superklass)->singleton()) {
2778     const TypeKlassPtr* superk = gvn.type(superklass)->is_klassptr();
2779     const TypeKlassPtr* subk   = gvn.type(subklass)->is_klassptr();
2780 
2781     // In the common case of an exact superklass, try to fold up the
2782     // test before generating code.  You may ask, why not just generate
2783     // the code and then let it fold up?  The answer is that the generated
2784     // code will necessarily include null checks, which do not always
2785     // completely fold away.  If they are also needless, then they turn
2786     // into a performance loss.  Example:
2787     //    Foo[] fa = blah(); Foo x = fa[0]; fa[1] = x;
2788     // Here, the type of 'fa' is often exact, so the store check
2789     // of fa[1]=x will fold up, without testing the nullness of x.
2790     //
2791     // At macro expansion, we would have already folded the SubTypeCheckNode
2792     // being expanded here because we always perform the static sub type
2793     // check in SubTypeCheckNode::sub() regardless of whether
2794     // StressReflectiveCode is set or not. We can therefore skip this
2795     // static check when StressReflectiveCode is on.
2796     switch (C->static_subtype_check(superk, subk)) {
2797     case Compile::SSC_always_false:
2798       {
2799         Node* always_fail = *ctrl;
2800         *ctrl = gvn.C->top();
2801         return always_fail;
2802       }
2803     case Compile::SSC_always_true:
2804       return C->top();
2805     case Compile::SSC_easy_test:
2806       {
2807         // Just do a direct pointer compare and be done.
2808         IfNode* iff = gen_subtype_check_compare(*ctrl, subklass, superklass, BoolTest::eq, PROB_STATIC_FREQUENT, gvn, T_ADDRESS);
2809         *ctrl = gvn.transform(new IfTrueNode(iff));
2810         return gvn.transform(new IfFalseNode(iff));
2811       }
2812     case Compile::SSC_full_test:
2813       break;
2814     default:
2815       ShouldNotReachHere();
2816     }
2817   }
2818 
2819   // %%% Possible further optimization:  Even if the superklass is not exact,
2820   // if the subklass is the unique subtype of the superklass, the check
2821   // will always succeed.  We could leave a dependency behind to ensure this.
2822 
2823   // First load the super-klass's check-offset
2824   Node* p1 = gvn.transform(AddPNode::make_off_heap(superklass, gvn.MakeConX(in_bytes(Klass::super_check_offset_offset()))));
2825   Node* m = C->immutable_memory();
2826   Node* chk_off = gvn.transform(new LoadINode(nullptr, m, p1, gvn.type(p1)->is_ptr(), TypeInt::INT, MemNode::unordered));
2827   int cacheoff_con = in_bytes(Klass::secondary_super_cache_offset());
2828   const TypeInt* chk_off_t = chk_off->Value(&gvn)->isa_int();
2829   int chk_off_con = (chk_off_t != nullptr && chk_off_t->is_con()) ? chk_off_t->get_con() : cacheoff_con;
2830   bool might_be_cache = (chk_off_con == cacheoff_con);
2831 
2832   // Load from the sub-klass's super-class display list, or a 1-word cache of
2833   // the secondary superclass list, or a failing value with a sentinel offset
2834   // if the super-klass is an interface or exceptionally deep in the Java
2835   // hierarchy and we have to scan the secondary superclass list the hard way.
2836   // Worst-case type is a little odd: null is allowed as a result (usually
2837   // klass loads can never produce a null).
2838   Node *chk_off_X = chk_off;
2839 #ifdef _LP64
2840   chk_off_X = gvn.transform(new ConvI2LNode(chk_off_X));
2841 #endif
2842   Node* p2 = gvn.transform(AddPNode::make_off_heap(subklass, chk_off_X));
2843   // For some types like interfaces the following loadKlass is from a 1-word
2844   // cache which is mutable so can't use immutable memory.  Other
2845   // types load from the super-class display table which is immutable.
2846   Node* kmem = C->immutable_memory();
2847   // secondary_super_cache is not immutable but can be treated as such because:
2848   // - no ideal node writes to it in a way that could cause an
2849   //   incorrect/missed optimization of the following Load.
2850   // - it's a cache so, worse case, not reading the latest value
2851   //   wouldn't cause incorrect execution
2852   if (might_be_cache && mem != nullptr) {
2853     kmem = mem->is_MergeMem() ? mem->as_MergeMem()->memory_at(C->get_alias_index(gvn.type(p2)->is_ptr())) : mem;
2854   }
2855   Node* nkls = gvn.transform(LoadKlassNode::make(gvn, kmem, p2, gvn.type(p2)->is_ptr(), TypeInstKlassPtr::OBJECT_OR_NULL));
2856 
2857   // Compile speed common case: ARE a subtype and we canNOT fail
2858   if (superklass == nkls) {
2859     return C->top();             // false path is dead; no test needed.
2860   }
2861 
2862   // Gather the various success & failures here
2863   RegionNode* r_not_subtype = new RegionNode(3);
2864   gvn.record_for_igvn(r_not_subtype);
2865   RegionNode* r_ok_subtype = new RegionNode(4);
2866   gvn.record_for_igvn(r_ok_subtype);
2867 
2868   // If we might perform an expensive check, first try to take advantage of profile data that was attached to the
2869   // SubTypeCheck node
2870   if (might_be_cache && method != nullptr && VM_Version::profile_all_receivers_at_type_check()) {
2871     ciCallProfile profile = method->call_profile_at_bci(bci);
2872     float total_prob = 0;
2873     for (int i = 0; profile.has_receiver(i); ++i) {
2874       float prob = profile.receiver_prob(i);
2875       total_prob += prob;
2876     }
2877     if (total_prob * 100. >= TypeProfileSubTypeCheckCommonThreshold) {
2878       const TypeKlassPtr* superk = gvn.type(superklass)->is_klassptr();
2879       for (int i = 0; profile.has_receiver(i); ++i) {
2880         ciKlass* klass = profile.receiver(i);
2881         const TypeKlassPtr* klass_t = TypeKlassPtr::make(klass);
2882         Compile::SubTypeCheckResult result = C->static_subtype_check(superk, klass_t);
2883         if (result != Compile::SSC_always_true && result != Compile::SSC_always_false) {
2884           continue;
2885         }
2886         float prob = profile.receiver_prob(i);
2887         ConNode* klass_node = gvn.makecon(klass_t);
2888         IfNode* iff = gen_subtype_check_compare(*ctrl, subklass, klass_node, BoolTest::eq, prob, gvn, T_ADDRESS);
2889         Node* iftrue = gvn.transform(new IfTrueNode(iff));
2890 
2891         if (result == Compile::SSC_always_true) {
2892           r_ok_subtype->add_req(iftrue);
2893         } else {
2894           assert(result == Compile::SSC_always_false, "");
2895           r_not_subtype->add_req(iftrue);
2896         }
2897         *ctrl = gvn.transform(new IfFalseNode(iff));
2898       }
2899     }
2900   }
2901 
2902   // See if we get an immediate positive hit.  Happens roughly 83% of the
2903   // time.  Test to see if the value loaded just previously from the subklass
2904   // is exactly the superklass.
2905   IfNode *iff1 = gen_subtype_check_compare(*ctrl, superklass, nkls, BoolTest::eq, PROB_LIKELY(0.83f), gvn, T_ADDRESS);
2906   Node *iftrue1 = gvn.transform( new IfTrueNode (iff1));
2907   *ctrl = gvn.transform(new IfFalseNode(iff1));
2908 
2909   // Compile speed common case: Check for being deterministic right now.  If
2910   // chk_off is a constant and not equal to cacheoff then we are NOT a
2911   // subklass.  In this case we need exactly the 1 test above and we can
2912   // return those results immediately.
2913   if (!might_be_cache) {
2914     Node* not_subtype_ctrl = *ctrl;
2915     *ctrl = iftrue1; // We need exactly the 1 test above
2916     PhaseIterGVN* igvn = gvn.is_IterGVN();
2917     if (igvn != nullptr) {
2918       igvn->remove_globally_dead_node(r_ok_subtype, PhaseIterGVN::NodeOrigin::Speculative);
2919       igvn->remove_globally_dead_node(r_not_subtype, PhaseIterGVN::NodeOrigin::Speculative);
2920     }
2921     return not_subtype_ctrl;
2922   }
2923 
2924   r_ok_subtype->init_req(1, iftrue1);
2925 
2926   // Check for immediate negative hit.  Happens roughly 11% of the time (which
2927   // is roughly 63% of the remaining cases).  Test to see if the loaded
2928   // check-offset points into the subklass display list or the 1-element
2929   // cache.  If it points to the display (and NOT the cache) and the display
2930   // missed then it's not a subtype.
2931   Node *cacheoff = gvn.intcon(cacheoff_con);
2932   IfNode *iff2 = gen_subtype_check_compare(*ctrl, chk_off, cacheoff, BoolTest::ne, PROB_LIKELY(0.63f), gvn, T_INT);
2933   r_not_subtype->init_req(1, gvn.transform(new IfTrueNode (iff2)));
2934   *ctrl = gvn.transform(new IfFalseNode(iff2));
2935 
2936   // Check for self.  Very rare to get here, but it is taken 1/3 the time.
2937   // No performance impact (too rare) but allows sharing of secondary arrays
2938   // which has some footprint reduction.
2939   IfNode *iff3 = gen_subtype_check_compare(*ctrl, subklass, superklass, BoolTest::eq, PROB_LIKELY(0.36f), gvn, T_ADDRESS);
2940   r_ok_subtype->init_req(2, gvn.transform(new IfTrueNode(iff3)));
2941   *ctrl = gvn.transform(new IfFalseNode(iff3));
2942 
2943   // -- Roads not taken here: --
2944   // We could also have chosen to perform the self-check at the beginning
2945   // of this code sequence, as the assembler does.  This would not pay off
2946   // the same way, since the optimizer, unlike the assembler, can perform
2947   // static type analysis to fold away many successful self-checks.
2948   // Non-foldable self checks work better here in second position, because
2949   // the initial primary superclass check subsumes a self-check for most
2950   // types.  An exception would be a secondary type like array-of-interface,
2951   // which does not appear in its own primary supertype display.
2952   // Finally, we could have chosen to move the self-check into the
2953   // PartialSubtypeCheckNode, and from there out-of-line in a platform
2954   // dependent manner.  But it is worthwhile to have the check here,
2955   // where it can be perhaps be optimized.  The cost in code space is
2956   // small (register compare, branch).
2957 
2958   // Now do a linear scan of the secondary super-klass array.  Again, no real
2959   // performance impact (too rare) but it's gotta be done.
2960   // Since the code is rarely used, there is no penalty for moving it
2961   // out of line, and it can only improve I-cache density.
2962   // The decision to inline or out-of-line this final check is platform
2963   // dependent, and is found in the AD file definition of PartialSubtypeCheck.
2964   Node* psc = gvn.transform(
2965     new PartialSubtypeCheckNode(*ctrl, subklass, superklass));
2966 
2967   IfNode *iff4 = gen_subtype_check_compare(*ctrl, psc, gvn.zerocon(T_OBJECT), BoolTest::ne, PROB_FAIR, gvn, T_ADDRESS);
2968   r_not_subtype->init_req(2, gvn.transform(new IfTrueNode (iff4)));
2969   r_ok_subtype ->init_req(3, gvn.transform(new IfFalseNode(iff4)));
2970 
2971   // Return false path; set default control to true path.
2972   *ctrl = gvn.transform(r_ok_subtype);
2973   return gvn.transform(r_not_subtype);
2974 }
2975 
2976 Node* GraphKit::gen_subtype_check(Node* obj_or_subklass, Node* superklass) {
2977   bool expand_subtype_check = C->post_loop_opts_phase(); // macro node expansion is over
2978   if (expand_subtype_check) {
2979     MergeMemNode* mem = merged_memory();
2980     Node* ctrl = control();
2981     Node* subklass = obj_or_subklass;
2982     if (!_gvn.type(obj_or_subklass)->isa_klassptr()) {
2983       subklass = load_object_klass(obj_or_subklass);
2984     }
2985 
2986     Node* n = Phase::gen_subtype_check(subklass, superklass, &ctrl, mem, _gvn, method(), bci());
2987     set_control(ctrl);
2988     return n;
2989   }
2990 
2991   Node* check = _gvn.transform(new SubTypeCheckNode(C, obj_or_subklass, superklass, method(), bci()));
2992   Node* bol = _gvn.transform(new BoolNode(check, BoolTest::eq));
2993   IfNode* iff = create_and_xform_if(control(), bol, PROB_STATIC_FREQUENT, COUNT_UNKNOWN);
2994   set_control(_gvn.transform(new IfTrueNode(iff)));
2995   return _gvn.transform(new IfFalseNode(iff));
2996 }
2997 
2998 // Profile-driven exact type check:
2999 Node* GraphKit::type_check_receiver(Node* receiver, ciKlass* klass,
3000                                     float prob,
3001                                     Node* *casted_receiver) {
3002   assert(!klass->is_interface(), "no exact type check on interfaces");
3003 
3004   const TypeKlassPtr* tklass = TypeKlassPtr::make(klass, Type::trust_interfaces);
3005   Node* recv_klass = load_object_klass(receiver);
3006   Node* want_klass = makecon(tklass);
3007   Node* cmp = _gvn.transform(new CmpPNode(recv_klass, want_klass));
3008   Node* bol = _gvn.transform(new BoolNode(cmp, BoolTest::eq));
3009   IfNode* iff = create_and_xform_if(control(), bol, prob, COUNT_UNKNOWN);
3010   set_control( _gvn.transform(new IfTrueNode (iff)));
3011   Node* fail = _gvn.transform(new IfFalseNode(iff));
3012 
3013   if (!stopped()) {
3014     const TypeOopPtr* receiver_type = _gvn.type(receiver)->isa_oopptr();
3015     const TypeOopPtr* recvx_type = tklass->as_instance_type();
3016     assert(recvx_type->klass_is_exact(), "");
3017 
3018     if (!receiver_type->higher_equal(recvx_type)) { // ignore redundant casts
3019       // Subsume downstream occurrences of receiver with a cast to
3020       // recv_xtype, since now we know what the type will be.
3021       Node* cast = new CheckCastPPNode(control(), receiver, recvx_type);
3022       (*casted_receiver) = _gvn.transform(cast);
3023       assert(!(*casted_receiver)->is_top(), "that path should be unreachable");
3024       // (User must make the replace_in_map call.)
3025     }
3026   }
3027 
3028   return fail;
3029 }
3030 
3031 //------------------------------subtype_check_receiver-------------------------
3032 Node* GraphKit::subtype_check_receiver(Node* receiver, ciKlass* klass,
3033                                        Node** casted_receiver) {
3034   const TypeKlassPtr* tklass = TypeKlassPtr::make(klass, Type::trust_interfaces)->try_improve();
3035   Node* want_klass = makecon(tklass);
3036 
3037   Node* slow_ctl = gen_subtype_check(receiver, want_klass);
3038 
3039   // Ignore interface type information until interface types are properly tracked.
3040   if (!stopped() && !klass->is_interface()) {
3041     const TypeOopPtr* receiver_type = _gvn.type(receiver)->isa_oopptr();
3042     const TypeOopPtr* recv_type = tklass->cast_to_exactness(false)->is_klassptr()->as_instance_type();
3043     if (!receiver_type->higher_equal(recv_type)) { // ignore redundant casts
3044       Node* cast = new CheckCastPPNode(control(), receiver, recv_type);
3045       (*casted_receiver) = _gvn.transform(cast);
3046     }
3047   }
3048 
3049   return slow_ctl;
3050 }
3051 
3052 //------------------------------seems_never_null-------------------------------
3053 // Use null_seen information if it is available from the profile.
3054 // If we see an unexpected null at a type check we record it and force a
3055 // recompile; the offending check will be recompiled to handle nulls.
3056 // If we see several offending BCIs, then all checks in the
3057 // method will be recompiled.
3058 bool GraphKit::seems_never_null(Node* obj, ciProfileData* data, bool& speculating) {
3059   speculating = !_gvn.type(obj)->speculative_maybe_null();
3060   Deoptimization::DeoptReason reason = Deoptimization::reason_null_check(speculating);
3061   if (UncommonNullCast               // Cutout for this technique
3062       && obj != null()               // And not the -Xcomp stupid case?
3063       && !too_many_traps(reason)
3064       ) {
3065     if (speculating) {
3066       return true;
3067     }
3068     if (data == nullptr)
3069       // Edge case:  no mature data.  Be optimistic here.
3070       return true;
3071     // If the profile has not seen a null, assume it won't happen.
3072     assert(java_bc() == Bytecodes::_checkcast ||
3073            java_bc() == Bytecodes::_instanceof ||
3074            java_bc() == Bytecodes::_aastore, "MDO must collect null_seen bit here");
3075     return !data->as_BitData()->null_seen();
3076   }
3077   speculating = false;
3078   return false;
3079 }
3080 
3081 void GraphKit::guard_klass_being_initialized(Node* klass) {
3082   int init_state_off = in_bytes(InstanceKlass::init_state_offset());
3083   Node* adr = off_heap_plus_addr(klass, init_state_off);
3084   Node* init_state = LoadNode::make(_gvn, nullptr, immutable_memory(), adr,
3085                                     adr->bottom_type()->is_ptr(), TypeInt::BYTE,
3086                                     T_BYTE, MemNode::acquire);
3087   init_state = _gvn.transform(init_state);
3088 
3089   Node* being_initialized_state = makecon(TypeInt::make(InstanceKlass::being_initialized));
3090 
3091   Node* chk = _gvn.transform(new CmpINode(being_initialized_state, init_state));
3092   Node* tst = _gvn.transform(new BoolNode(chk, BoolTest::eq));
3093 
3094   { BuildCutout unless(this, tst, PROB_MAX);
3095     uncommon_trap(Deoptimization::Reason_initialized, Deoptimization::Action_reinterpret);
3096   }
3097 }
3098 
3099 void GraphKit::guard_init_thread(Node* klass) {
3100   int init_thread_off = in_bytes(InstanceKlass::init_thread_offset());
3101   Node* adr = off_heap_plus_addr(klass, init_thread_off);
3102 
3103   Node* init_thread = LoadNode::make(_gvn, nullptr, immutable_memory(), adr,
3104                                      adr->bottom_type()->is_ptr(), TypePtr::NOTNULL,
3105                                      T_ADDRESS, MemNode::unordered);
3106   init_thread = _gvn.transform(init_thread);
3107 
3108   Node* cur_thread = _gvn.transform(new ThreadLocalNode());
3109 
3110   Node* chk = _gvn.transform(new CmpPNode(cur_thread, init_thread));
3111   Node* tst = _gvn.transform(new BoolNode(chk, BoolTest::eq));
3112 
3113   { BuildCutout unless(this, tst, PROB_MAX);
3114     uncommon_trap(Deoptimization::Reason_uninitialized, Deoptimization::Action_none);
3115   }
3116 }
3117 
3118 void GraphKit::clinit_barrier(ciInstanceKlass* ik, ciMethod* context) {
3119   if (ik->is_being_initialized()) {
3120     if (C->needs_clinit_barrier(ik, context)) {
3121       Node* klass = makecon(TypeKlassPtr::make(ik));
3122       guard_klass_being_initialized(klass);
3123       guard_init_thread(klass);
3124       insert_mem_bar(Op_MemBarCPUOrder);
3125     }
3126   } else if (ik->is_initialized()) {
3127     return; // no barrier needed
3128   } else {
3129     uncommon_trap(Deoptimization::Reason_uninitialized,
3130                   Deoptimization::Action_reinterpret,
3131                   nullptr);
3132   }
3133 }
3134 
3135 //------------------------maybe_cast_profiled_receiver-------------------------
3136 // If the profile has seen exactly one type, narrow to exactly that type.
3137 // Subsequent type checks will always fold up.
3138 Node* GraphKit::maybe_cast_profiled_receiver(Node* not_null_obj,
3139                                              const TypeKlassPtr* require_klass,
3140                                              ciKlass* spec_klass,
3141                                              bool safe_for_replace) {
3142   if (!UseTypeProfile || !TypeProfileCasts) return nullptr;
3143 
3144   Deoptimization::DeoptReason reason = Deoptimization::reason_class_check(spec_klass != nullptr);
3145 
3146   // Make sure we haven't already deoptimized from this tactic.
3147   if (too_many_traps_or_recompiles(reason))
3148     return nullptr;
3149 
3150   // (No, this isn't a call, but it's enough like a virtual call
3151   // to use the same ciMethod accessor to get the profile info...)
3152   // If we have a speculative type use it instead of profiling (which
3153   // may not help us)
3154   ciKlass* exact_kls = spec_klass == nullptr ? profile_has_unique_klass() : spec_klass;
3155   if (exact_kls != nullptr) {// no cast failures here
3156     if (require_klass == nullptr ||
3157         C->static_subtype_check(require_klass, TypeKlassPtr::make(exact_kls, Type::trust_interfaces)) == Compile::SSC_always_true) {
3158       // If we narrow the type to match what the type profile sees or
3159       // the speculative type, we can then remove the rest of the
3160       // cast.
3161       // This is a win, even if the exact_kls is very specific,
3162       // because downstream operations, such as method calls,
3163       // will often benefit from the sharper type.
3164       Node* exact_obj = not_null_obj; // will get updated in place...
3165       Node* slow_ctl  = type_check_receiver(exact_obj, exact_kls, 1.0,
3166                                             &exact_obj);
3167       { PreserveJVMState pjvms(this);
3168         set_control(slow_ctl);
3169         uncommon_trap_exact(reason, Deoptimization::Action_maybe_recompile);
3170       }
3171       if (safe_for_replace) {
3172         replace_in_map(not_null_obj, exact_obj);
3173       }
3174       return exact_obj;
3175     }
3176     // assert(ssc == Compile::SSC_always_true)... except maybe the profile lied to us.
3177   }
3178 
3179   return nullptr;
3180 }
3181 
3182 /**
3183  * Cast obj to type and emit guard unless we had too many traps here
3184  * already
3185  *
3186  * @param obj       node being casted
3187  * @param type      type to cast the node to
3188  * @param not_null  true if we know node cannot be null
3189  */
3190 Node* GraphKit::maybe_cast_profiled_obj(Node* obj,
3191                                         ciKlass* type,
3192                                         bool not_null) {
3193   if (stopped()) {
3194     return obj;
3195   }
3196 
3197   // type is null if profiling tells us this object is always null
3198   if (type != nullptr) {
3199     Deoptimization::DeoptReason class_reason = Deoptimization::Reason_speculate_class_check;
3200     Deoptimization::DeoptReason null_reason = Deoptimization::Reason_speculate_null_check;
3201 
3202     if (!too_many_traps_or_recompiles(null_reason) &&
3203         !too_many_traps_or_recompiles(class_reason)) {
3204       Node* not_null_obj = nullptr;
3205       // not_null is true if we know the object is not null and
3206       // there's no need for a null check
3207       if (!not_null) {
3208         Node* null_ctl = top();
3209         not_null_obj = null_check_oop(obj, &null_ctl, true, true, true);
3210         assert(null_ctl->is_top(), "no null control here");
3211       } else {
3212         not_null_obj = obj;
3213       }
3214 
3215       Node* exact_obj = not_null_obj;
3216       ciKlass* exact_kls = type;
3217       Node* slow_ctl  = type_check_receiver(exact_obj, exact_kls, 1.0,
3218                                             &exact_obj);
3219       {
3220         PreserveJVMState pjvms(this);
3221         set_control(slow_ctl);
3222         uncommon_trap_exact(class_reason, Deoptimization::Action_maybe_recompile);
3223       }
3224       replace_in_map(not_null_obj, exact_obj);
3225       obj = exact_obj;
3226     }
3227   } else {
3228     if (!too_many_traps_or_recompiles(Deoptimization::Reason_null_assert)) {
3229       Node* exact_obj = null_assert(obj);
3230       replace_in_map(obj, exact_obj);
3231       obj = exact_obj;
3232     }
3233   }
3234   return obj;
3235 }
3236 
3237 //-------------------------------gen_instanceof--------------------------------
3238 // Generate an instance-of idiom.  Used by both the instance-of bytecode
3239 // and the reflective instance-of call.
3240 Node* GraphKit::gen_instanceof(Node* obj, Node* superklass, bool safe_for_replace) {
3241   kill_dead_locals();           // Benefit all the uncommon traps
3242   assert( !stopped(), "dead parse path should be checked in callers" );
3243   assert(!TypePtr::NULL_PTR->higher_equal(_gvn.type(superklass)->is_klassptr()),
3244          "must check for not-null not-dead klass in callers");
3245 
3246   // Make the merge point
3247   enum { _obj_path = 1, _fail_path, _null_path, PATH_LIMIT };
3248   RegionNode* region = new RegionNode(PATH_LIMIT);
3249   Node*       phi    = new PhiNode(region, TypeInt::BOOL);
3250   C->set_has_split_ifs(true); // Has chance for split-if optimization
3251 
3252   ciProfileData* data = nullptr;
3253   if (java_bc() == Bytecodes::_instanceof) {  // Only for the bytecode
3254     data = method()->method_data()->bci_to_data(bci());
3255   }
3256   bool speculative_not_null = false;
3257   bool never_see_null = (ProfileDynamicTypes  // aggressive use of profile
3258                          && seems_never_null(obj, data, speculative_not_null));
3259 
3260   // Null check; get casted pointer; set region slot 3
3261   Node* null_ctl = top();
3262   Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null, safe_for_replace, speculative_not_null);
3263 
3264   // If not_null_obj is dead, only null-path is taken
3265   if (stopped()) {              // Doing instance-of on a null?
3266     set_control(null_ctl);
3267     return intcon(0);
3268   }
3269   region->init_req(_null_path, null_ctl);
3270   phi   ->init_req(_null_path, intcon(0)); // Set null path value
3271   if (null_ctl == top()) {
3272     // Do this eagerly, so that pattern matches like is_diamond_phi
3273     // will work even during parsing.
3274     assert(_null_path == PATH_LIMIT-1, "delete last");
3275     region->del_req(_null_path);
3276     phi   ->del_req(_null_path);
3277   }
3278 
3279   // Do we know the type check always succeed?
3280   bool known_statically = false;
3281   if (_gvn.type(superklass)->singleton()) {
3282     const TypeKlassPtr* superk = _gvn.type(superklass)->is_klassptr();
3283     const TypeKlassPtr* subk = _gvn.type(obj)->is_oopptr()->as_klass_type();
3284     if (subk->is_loaded()) {
3285       int static_res = C->static_subtype_check(superk, subk);
3286       known_statically = (static_res == Compile::SSC_always_true || static_res == Compile::SSC_always_false);
3287     }
3288   }
3289 
3290   if (!known_statically) {
3291     const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
3292     // We may not have profiling here or it may not help us. If we
3293     // have a speculative type use it to perform an exact cast.
3294     ciKlass* spec_obj_type = obj_type->speculative_type();
3295     if (spec_obj_type != nullptr || (ProfileDynamicTypes && data != nullptr)) {
3296       Node* cast_obj = maybe_cast_profiled_receiver(not_null_obj, nullptr, spec_obj_type, safe_for_replace);
3297       if (stopped()) {            // Profile disagrees with this path.
3298         set_control(null_ctl);    // Null is the only remaining possibility.
3299         return intcon(0);
3300       }
3301       if (cast_obj != nullptr) {
3302         not_null_obj = cast_obj;
3303       }
3304     }
3305   }
3306 
3307   // Generate the subtype check
3308   Node* not_subtype_ctrl = gen_subtype_check(not_null_obj, superklass);
3309 
3310   // Plug in the success path to the general merge in slot 1.
3311   region->init_req(_obj_path, control());
3312   phi   ->init_req(_obj_path, intcon(1));
3313 
3314   // Plug in the failing path to the general merge in slot 2.
3315   region->init_req(_fail_path, not_subtype_ctrl);
3316   phi   ->init_req(_fail_path, intcon(0));
3317 
3318   // Return final merged results
3319   set_control( _gvn.transform(region) );
3320   record_for_igvn(region);
3321 
3322   // If we know the type check always succeeds then we don't use the
3323   // profiling data at this bytecode. Don't lose it, feed it to the
3324   // type system as a speculative type.
3325   if (safe_for_replace) {
3326     Node* casted_obj = record_profiled_receiver_for_speculation(obj);
3327     replace_in_map(obj, casted_obj);
3328   }
3329 
3330   return _gvn.transform(phi);
3331 }
3332 
3333 //-------------------------------gen_checkcast---------------------------------
3334 // Generate a checkcast idiom.  Used by both the checkcast bytecode and the
3335 // array store bytecode.  Stack must be as-if BEFORE doing the bytecode so the
3336 // uncommon-trap paths work.  Adjust stack after this call.
3337 // If failure_control is supplied and not null, it is filled in with
3338 // the control edge for the cast failure.  Otherwise, an appropriate
3339 // uncommon trap or exception is thrown.
3340 Node* GraphKit::gen_checkcast(Node *obj, Node* superklass,
3341                               Node* *failure_control) {
3342   kill_dead_locals();           // Benefit all the uncommon traps
3343   const TypeKlassPtr* klass_ptr_type = _gvn.type(superklass)->is_klassptr();
3344   const TypeKlassPtr* improved_klass_ptr_type = klass_ptr_type->try_improve();
3345   const TypeOopPtr* toop = improved_klass_ptr_type->cast_to_exactness(false)->as_instance_type();
3346 
3347   // Fast cutout:  Check the case that the cast is vacuously true.
3348   // This detects the common cases where the test will short-circuit
3349   // away completely.  We do this before we perform the null check,
3350   // because if the test is going to turn into zero code, we don't
3351   // want a residual null check left around.  (Causes a slowdown,
3352   // for example, in some objArray manipulations, such as a[i]=a[j].)
3353   if (improved_klass_ptr_type->singleton()) {
3354     const TypeOopPtr* objtp = _gvn.type(obj)->isa_oopptr();
3355     if (objtp != nullptr) {
3356       switch (C->static_subtype_check(improved_klass_ptr_type, objtp->as_klass_type())) {
3357       case Compile::SSC_always_true:
3358         // If we know the type check always succeed then we don't use
3359         // the profiling data at this bytecode. Don't lose it, feed it
3360         // to the type system as a speculative type.
3361         return record_profiled_receiver_for_speculation(obj);
3362       case Compile::SSC_always_false:
3363         // It needs a null check because a null will *pass* the cast check.
3364         // A non-null value will always produce an exception.
3365         if (!objtp->maybe_null()) {
3366           bool is_aastore = (java_bc() == Bytecodes::_aastore);
3367           Deoptimization::DeoptReason reason = is_aastore ?
3368             Deoptimization::Reason_array_check : Deoptimization::Reason_class_check;
3369           builtin_throw(reason);
3370           return top();
3371         } else if (!too_many_traps_or_recompiles(Deoptimization::Reason_null_assert)) {
3372           return null_assert(obj);
3373         }
3374         break; // Fall through to full check
3375       default:
3376         break;
3377       }
3378     }
3379   }
3380 
3381   ciProfileData* data = nullptr;
3382   bool safe_for_replace = false;
3383   if (failure_control == nullptr) {        // use MDO in regular case only
3384     assert(java_bc() == Bytecodes::_aastore ||
3385            java_bc() == Bytecodes::_checkcast,
3386            "interpreter profiles type checks only for these BCs");
3387     data = method()->method_data()->bci_to_data(bci());
3388     safe_for_replace = true;
3389   }
3390 
3391   // Make the merge point
3392   enum { _obj_path = 1, _null_path, PATH_LIMIT };
3393   RegionNode* region = new RegionNode(PATH_LIMIT);
3394   Node*       phi    = new PhiNode(region, toop);
3395   C->set_has_split_ifs(true); // Has chance for split-if optimization
3396 
3397   // Use null-cast information if it is available
3398   bool speculative_not_null = false;
3399   bool never_see_null = ((failure_control == nullptr)  // regular case only
3400                          && seems_never_null(obj, data, speculative_not_null));
3401 
3402   // Null check; get casted pointer; set region slot 3
3403   Node* null_ctl = top();
3404   Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null, false /*safe_for_replace*/, speculative_not_null);
3405 
3406   // If not_null_obj is dead, only null-path is taken
3407   if (stopped()) {              // Doing instance-of on a null?
3408     set_control(null_ctl);
3409     return null();
3410   }
3411   region->init_req(_null_path, null_ctl);
3412   phi   ->init_req(_null_path, null());  // Set null path value
3413   if (null_ctl == top()) {
3414     // Do this eagerly, so that pattern matches like is_diamond_phi
3415     // will work even during parsing.
3416     assert(_null_path == PATH_LIMIT-1, "delete last");
3417     region->del_req(_null_path);
3418     phi   ->del_req(_null_path);
3419   }
3420 
3421   Node* cast_obj = nullptr;
3422   if (improved_klass_ptr_type->klass_is_exact()) {
3423     // The following optimization tries to statically cast the speculative type of the object
3424     // (for example obtained during profiling) to the type of the superklass and then do a
3425     // dynamic check that the type of the object is what we expect. To work correctly
3426     // for checkcast and aastore the type of superklass should be exact.
3427     const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
3428     // We may not have profiling here or it may not help us. If we have
3429     // a speculative type use it to perform an exact cast.
3430     ciKlass* spec_obj_type = obj_type->speculative_type();
3431     if (spec_obj_type != nullptr || data != nullptr) {
3432       cast_obj = maybe_cast_profiled_receiver(not_null_obj, improved_klass_ptr_type, spec_obj_type, false /*safe_for_replace*/);
3433       if (cast_obj != nullptr) {
3434         if (failure_control != nullptr) // failure is now impossible
3435           (*failure_control) = top();
3436         // adjust the type of the phi to the exact klass:
3437         phi->raise_bottom_type(_gvn.type(cast_obj)->meet_speculative(TypePtr::NULL_PTR));
3438       }
3439     }
3440   }
3441 
3442   if (cast_obj == nullptr) {
3443     // Generate the subtype check
3444     Node* improved_superklass = superklass;
3445     if (improved_klass_ptr_type != klass_ptr_type && improved_klass_ptr_type->singleton()) {
3446       improved_superklass = makecon(improved_klass_ptr_type);
3447     }
3448     Node* not_subtype_ctrl = gen_subtype_check(not_null_obj, improved_superklass);
3449 
3450     // Plug in success path into the merge
3451     cast_obj = _gvn.transform(new CheckCastPPNode(control(), not_null_obj, toop));
3452     // Failure path ends in uncommon trap (or may be dead - failure impossible)
3453     if (failure_control == nullptr) {
3454       if (not_subtype_ctrl != top()) { // If failure is possible
3455         PreserveJVMState pjvms(this);
3456         set_control(not_subtype_ctrl);
3457         bool is_aastore = (java_bc() == Bytecodes::_aastore);
3458         Deoptimization::DeoptReason reason = is_aastore ?
3459           Deoptimization::Reason_array_check : Deoptimization::Reason_class_check;
3460         builtin_throw(reason);
3461       }
3462     } else {
3463       (*failure_control) = not_subtype_ctrl;
3464     }
3465   }
3466 
3467   region->init_req(_obj_path, control());
3468   phi   ->init_req(_obj_path, cast_obj);
3469 
3470   // Return final merged results
3471   set_control( _gvn.transform(region) );
3472   record_for_igvn(region);
3473 
3474   // A merge of null or Casted-NotNull obj
3475   Node* res = _gvn.transform(phi);
3476   res = record_profiled_receiver_for_speculation(res);
3477   if (safe_for_replace) {
3478     replace_in_map(obj, res);
3479   }
3480   return res;
3481 }
3482 
3483 //------------------------------next_monitor-----------------------------------
3484 // What number should be given to the next monitor?
3485 int GraphKit::next_monitor() {
3486   int current = jvms()->monitor_depth()* C->sync_stack_slots();
3487   int next = current + C->sync_stack_slots();
3488   // Keep the toplevel high water mark current:
3489   if (C->fixed_slots() < next)  C->set_fixed_slots(next);
3490   return current;
3491 }
3492 
3493 //------------------------------insert_mem_bar---------------------------------
3494 // Memory barrier to avoid floating things around
3495 // The membar serves as a pinch point between both control and all memory slices.
3496 Node* GraphKit::insert_mem_bar(int opcode, Node* precedent) {
3497   MemBarNode* mb = MemBarNode::make(C, opcode, Compile::AliasIdxBot, precedent);
3498   mb->init_req(TypeFunc::Control, control());
3499   mb->init_req(TypeFunc::Memory,  reset_memory());
3500   Node* membar = _gvn.transform(mb);
3501   record_for_igvn(membar);
3502   set_control(_gvn.transform(new ProjNode(membar, TypeFunc::Control)));
3503   set_all_memory_call(membar);
3504   return membar;
3505 }
3506 
3507 //-------------------------insert_mem_bar_volatile----------------------------
3508 // Memory barrier to avoid floating things around
3509 // The membar serves as a pinch point between both control and memory(alias_idx).
3510 // If you want to make a pinch point on all memory slices, do not use this
3511 // function (even with AliasIdxBot); use insert_mem_bar() instead.
3512 Node* GraphKit::insert_mem_bar_volatile(int opcode, int alias_idx, Node* precedent) {
3513   // When Parse::do_put_xxx updates a volatile field, it appends a series
3514   // of MemBarVolatile nodes, one for *each* volatile field alias category.
3515   // The first membar is on the same memory slice as the field store opcode.
3516   // This forces the membar to follow the store.  (Bug 6500685 broke this.)
3517   // All the other membars (for other volatile slices, including AliasIdxBot,
3518   // which stands for all unknown volatile slices) are control-dependent
3519   // on the first membar.  This prevents later volatile loads or stores
3520   // from sliding up past the just-emitted store.
3521 
3522   MemBarNode* mb = MemBarNode::make(C, opcode, alias_idx, precedent);
3523   mb->set_req(TypeFunc::Control,control());
3524   if (alias_idx == Compile::AliasIdxBot) {
3525     mb->set_req(TypeFunc::Memory, merged_memory()->base_memory());
3526   } else {
3527     assert(!(opcode == Op_Initialize && alias_idx != Compile::AliasIdxRaw), "fix caller");
3528     mb->set_req(TypeFunc::Memory, memory(alias_idx));
3529   }
3530   Node* membar = _gvn.transform(mb);
3531   record_for_igvn(membar);
3532   set_control(_gvn.transform(new ProjNode(membar, TypeFunc::Control)));
3533   if (alias_idx == Compile::AliasIdxBot) {
3534     merged_memory()->set_base_memory(_gvn.transform(new ProjNode(membar, TypeFunc::Memory)));
3535   } else {
3536     set_memory(_gvn.transform(new ProjNode(membar, TypeFunc::Memory)),alias_idx);
3537   }
3538   return membar;
3539 }
3540 
3541 //------------------------------insert_reachability_fence----------------------
3542 Node* GraphKit::insert_reachability_fence(Node* referent) {
3543   assert(!referent->is_top(), "");
3544   Node* rf = _gvn.transform(new ReachabilityFenceNode(C, control(), referent));
3545   set_control(rf);
3546   C->record_for_igvn(rf);
3547   return rf;
3548 }
3549 
3550 //------------------------------shared_lock------------------------------------
3551 // Emit locking code.
3552 FastLockNode* GraphKit::shared_lock(Node* obj) {
3553   // bci is either a monitorenter bc or InvocationEntryBci
3554   // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
3555   assert(SynchronizationEntryBCI == InvocationEntryBci, "");
3556 
3557   if (stopped())                // Dead monitor?
3558     return nullptr;
3559 
3560   assert(dead_locals_are_killed(), "should kill locals before sync. point");
3561 
3562   // Box the stack location
3563   Node* box = new BoxLockNode(next_monitor());
3564   // Check for bailout after new BoxLockNode
3565   if (failing()) { return nullptr; }
3566   box = _gvn.transform(box);
3567   Node* mem = reset_memory();
3568 
3569   FastLockNode * flock = _gvn.transform(new FastLockNode(nullptr, obj, box) )->as_FastLock();
3570 
3571   // Add monitor to debug info for the slow path.  If we block inside the
3572   // slow path and de-opt, we need the monitor hanging around
3573   map()->push_monitor( flock );
3574 
3575   const TypeFunc *tf = LockNode::lock_type();
3576   LockNode *lock = new LockNode(C, tf);
3577 
3578   lock->init_req( TypeFunc::Control, control() );
3579   lock->init_req( TypeFunc::Memory , mem );
3580   lock->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
3581   lock->init_req( TypeFunc::FramePtr, frameptr() );
3582   lock->init_req( TypeFunc::ReturnAdr, top() );
3583 
3584   lock->init_req(TypeFunc::Parms + 0, obj);
3585   lock->init_req(TypeFunc::Parms + 1, box);
3586   lock->init_req(TypeFunc::Parms + 2, flock);
3587   add_safepoint_edges(lock);
3588 
3589   lock = _gvn.transform( lock )->as_Lock();
3590 
3591   // lock has no side-effects, sets few values
3592   set_predefined_output_for_runtime_call(lock, mem, TypeRawPtr::BOTTOM);
3593 
3594   insert_mem_bar(Op_MemBarAcquireLock);
3595 
3596   // Add this to the worklist so that the lock can be eliminated
3597   record_for_igvn(lock);
3598 
3599 #ifndef PRODUCT
3600   if (PrintLockStatistics) {
3601     // Update the counter for this lock.  Don't bother using an atomic
3602     // operation since we don't require absolute accuracy.
3603     lock->create_lock_counter(map()->jvms());
3604     increment_counter(lock->counter()->addr());
3605   }
3606 #endif
3607 
3608   return flock;
3609 }
3610 
3611 
3612 //------------------------------shared_unlock----------------------------------
3613 // Emit unlocking code.
3614 void GraphKit::shared_unlock(Node* box, Node* obj) {
3615   // bci is either a monitorenter bc or InvocationEntryBci
3616   // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
3617   assert(SynchronizationEntryBCI == InvocationEntryBci, "");
3618 
3619   if (stopped()) {               // Dead monitor?
3620     map()->pop_monitor();        // Kill monitor from debug info
3621     return;
3622   }
3623 
3624   // Memory barrier to avoid floating things down past the locked region
3625   insert_mem_bar(Op_MemBarReleaseLock);
3626 
3627   const TypeFunc *tf = OptoRuntime::complete_monitor_exit_Type();
3628   UnlockNode *unlock = new UnlockNode(C, tf);
3629 #ifdef ASSERT
3630   unlock->set_dbg_jvms(sync_jvms());
3631 #endif
3632   uint raw_idx = Compile::AliasIdxRaw;
3633   unlock->init_req( TypeFunc::Control, control() );
3634   unlock->init_req( TypeFunc::Memory , memory(raw_idx) );
3635   unlock->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
3636   unlock->init_req( TypeFunc::FramePtr, frameptr() );
3637   unlock->init_req( TypeFunc::ReturnAdr, top() );
3638 
3639   unlock->init_req(TypeFunc::Parms + 0, obj);
3640   unlock->init_req(TypeFunc::Parms + 1, box);
3641   unlock = _gvn.transform(unlock)->as_Unlock();
3642 
3643   Node* mem = reset_memory();
3644 
3645   // unlock has no side-effects, sets few values
3646   set_predefined_output_for_runtime_call(unlock, mem, TypeRawPtr::BOTTOM);
3647 
3648   // Kill monitor from debug info
3649   map()->pop_monitor( );
3650 }
3651 
3652 //-------------------------------get_layout_helper-----------------------------
3653 // If the given klass is a constant or known to be an array,
3654 // fetch the constant layout helper value into constant_value
3655 // and return null.  Otherwise, load the non-constant
3656 // layout helper value, and return the node which represents it.
3657 // This two-faced routine is useful because allocation sites
3658 // almost always feature constant types.
3659 Node* GraphKit::get_layout_helper(Node* klass_node, jint& constant_value) {
3660   const TypeKlassPtr* klass_t = _gvn.type(klass_node)->isa_klassptr();
3661   if (!StressReflectiveCode && klass_t != nullptr) {
3662     bool xklass = klass_t->klass_is_exact();
3663     if (xklass || (klass_t->isa_aryklassptr() && klass_t->is_aryklassptr()->elem() != Type::BOTTOM)) {
3664       jint lhelper;
3665       if (klass_t->isa_aryklassptr()) {
3666         BasicType elem = klass_t->as_instance_type()->isa_aryptr()->elem()->array_element_basic_type();
3667         if (is_reference_type(elem, true)) {
3668           elem = T_OBJECT;
3669         }
3670         lhelper = Klass::array_layout_helper(elem);
3671       } else {
3672         lhelper = klass_t->is_instklassptr()->exact_klass()->layout_helper();
3673       }
3674       if (lhelper != Klass::_lh_neutral_value) {
3675         constant_value = lhelper;
3676         return (Node*) nullptr;
3677       }
3678     }
3679   }
3680   constant_value = Klass::_lh_neutral_value;  // put in a known value
3681   Node* lhp = off_heap_plus_addr(klass_node, in_bytes(Klass::layout_helper_offset()));
3682   return make_load(nullptr, lhp, TypeInt::INT, T_INT, MemNode::unordered);
3683 }
3684 
3685 // We just put in an allocate/initialize with a big raw-memory effect.
3686 // Hook selected additional alias categories on the initialization.
3687 static void hook_memory_on_init(GraphKit& kit, int alias_idx,
3688                                 MergeMemNode* init_in_merge,
3689                                 Node* init_out_raw) {
3690   DEBUG_ONLY(Node* init_in_raw = init_in_merge->base_memory());
3691   assert(init_in_merge->memory_at(alias_idx) == init_in_raw, "");
3692 
3693   Node* prevmem = kit.memory(alias_idx);
3694   init_in_merge->set_memory_at(alias_idx, prevmem);
3695   kit.set_memory(init_out_raw, alias_idx);
3696 }
3697 
3698 //---------------------------set_output_for_allocation-------------------------
3699 Node* GraphKit::set_output_for_allocation(AllocateNode* alloc,
3700                                           const TypeOopPtr* oop_type,
3701                                           bool deoptimize_on_exception) {
3702   int rawidx = Compile::AliasIdxRaw;
3703   alloc->set_req( TypeFunc::FramePtr, frameptr() );
3704   add_safepoint_edges(alloc);
3705   Node* allocx = _gvn.transform(alloc);
3706   set_control( _gvn.transform(new ProjNode(allocx, TypeFunc::Control) ) );
3707   // create memory projection for i_o
3708   set_memory ( _gvn.transform( new ProjNode(allocx, TypeFunc::Memory, true) ), rawidx );
3709   make_slow_call_ex(allocx, env()->Throwable_klass(), true, deoptimize_on_exception);
3710 
3711   // create a memory projection as for the normal control path
3712   Node* malloc = _gvn.transform(new ProjNode(allocx, TypeFunc::Memory));
3713   set_memory(malloc, rawidx);
3714 
3715   // a normal slow-call doesn't change i_o, but an allocation does
3716   // we create a separate i_o projection for the normal control path
3717   set_i_o(_gvn.transform( new ProjNode(allocx, TypeFunc::I_O, false) ) );
3718   Node* rawoop = _gvn.transform( new ProjNode(allocx, TypeFunc::Parms) );
3719 
3720   // put in an initialization barrier
3721   InitializeNode* init = insert_mem_bar_volatile(Op_Initialize, rawidx,
3722                                                  rawoop)->as_Initialize();
3723   assert(alloc->initialization() == init,  "2-way macro link must work");
3724   assert(init ->allocation()     == alloc, "2-way macro link must work");
3725   {
3726     // Extract memory strands which may participate in the new object's
3727     // initialization, and source them from the new InitializeNode.
3728     // This will allow us to observe initializations when they occur,
3729     // and link them properly (as a group) to the InitializeNode.
3730     assert(init->in(InitializeNode::Memory) == malloc, "");
3731     MergeMemNode* minit_in = MergeMemNode::make(malloc);
3732     init->set_req(InitializeNode::Memory, minit_in);
3733     record_for_igvn(minit_in); // fold it up later, if possible
3734     Node* minit_out = memory(rawidx);
3735     assert(minit_out->is_Proj() && minit_out->in(0) == init, "");
3736     int mark_idx = C->get_alias_index(oop_type->add_offset(oopDesc::mark_offset_in_bytes()));
3737     // Add an edge in the MergeMem for the header fields so an access to one of those has correct memory state.
3738     // Use one NarrowMemProjNode per slice to properly record the adr type of each slice. The Initialize node will have
3739     // multiple projections as a result.
3740     set_memory(_gvn.transform(new NarrowMemProjNode(init, C->get_adr_type(mark_idx))), mark_idx);
3741     int klass_idx = C->get_alias_index(oop_type->add_offset(oopDesc::klass_offset_in_bytes()));
3742     set_memory(_gvn.transform(new NarrowMemProjNode(init, C->get_adr_type(klass_idx))), klass_idx);
3743     if (oop_type->isa_aryptr()) {
3744       const TypePtr* telemref = oop_type->add_offset(Type::OffsetBot);
3745       int            elemidx  = C->get_alias_index(telemref);
3746       hook_memory_on_init(*this, elemidx, minit_in, _gvn.transform(new NarrowMemProjNode(init, C->get_adr_type(elemidx))));
3747     } else if (oop_type->isa_instptr()) {
3748       ciInstanceKlass* ik = oop_type->is_instptr()->instance_klass();
3749       for (int i = 0, len = ik->nof_nonstatic_fields(); i < len; i++) {
3750         ciField* field = ik->nonstatic_field_at(i);
3751         if (field->offset_in_bytes() >= TrackedInitializationLimit * HeapWordSize)
3752           continue;  // do not bother to track really large numbers of fields
3753         // Find (or create) the alias category for this field:
3754         int fieldidx = C->alias_type(field)->index();
3755         hook_memory_on_init(*this, fieldidx, minit_in, _gvn.transform(new NarrowMemProjNode(init, C->get_adr_type(fieldidx))));
3756       }
3757     }
3758   }
3759 
3760   // Cast raw oop to the real thing...
3761   Node* javaoop = new CheckCastPPNode(control(), rawoop, oop_type);
3762   javaoop = _gvn.transform(javaoop);
3763   C->set_recent_alloc(control(), javaoop);
3764   assert(just_allocated_object(control()) == javaoop, "just allocated");
3765 
3766 #ifdef ASSERT
3767   { // Verify that the AllocateNode::Ideal_allocation recognizers work:
3768     assert(AllocateNode::Ideal_allocation(rawoop) == alloc,
3769            "Ideal_allocation works");
3770     assert(AllocateNode::Ideal_allocation(javaoop) == alloc,
3771            "Ideal_allocation works");
3772     if (alloc->is_AllocateArray()) {
3773       assert(AllocateArrayNode::Ideal_array_allocation(rawoop) == alloc->as_AllocateArray(),
3774              "Ideal_allocation works");
3775       assert(AllocateArrayNode::Ideal_array_allocation(javaoop) == alloc->as_AllocateArray(),
3776              "Ideal_allocation works");
3777     } else {
3778       assert(alloc->in(AllocateNode::ALength)->is_top(), "no length, please");
3779     }
3780   }
3781 #endif //ASSERT
3782 
3783   return javaoop;
3784 }
3785 
3786 //---------------------------new_instance--------------------------------------
3787 // This routine takes a klass_node which may be constant (for a static type)
3788 // or may be non-constant (for reflective code).  It will work equally well
3789 // for either, and the graph will fold nicely if the optimizer later reduces
3790 // the type to a constant.
3791 // The optional arguments are for specialized use by intrinsics:
3792 //  - If 'extra_slow_test' if not null is an extra condition for the slow-path.
3793 //  - If 'return_size_val', report the total object size to the caller.
3794 //  - deoptimize_on_exception controls how Java exceptions are handled (rethrow vs deoptimize)
3795 Node* GraphKit::new_instance(Node* klass_node,
3796                              Node* extra_slow_test,
3797                              Node* *return_size_val,
3798                              bool deoptimize_on_exception) {
3799   // Compute size in doublewords
3800   // The size is always an integral number of doublewords, represented
3801   // as a positive bytewise size stored in the klass's layout_helper.
3802   // The layout_helper also encodes (in a low bit) the need for a slow path.
3803   jint  layout_con = Klass::_lh_neutral_value;
3804   Node* layout_val = get_layout_helper(klass_node, layout_con);
3805   int   layout_is_con = (layout_val == nullptr);
3806 
3807   if (extra_slow_test == nullptr)  extra_slow_test = intcon(0);
3808   // Generate the initial go-slow test.  It's either ALWAYS (return a
3809   // Node for 1) or NEVER (return a null) or perhaps (in the reflective
3810   // case) a computed value derived from the layout_helper.
3811   Node* initial_slow_test = nullptr;
3812   if (layout_is_con) {
3813     assert(!StressReflectiveCode, "stress mode does not use these paths");
3814     bool must_go_slow = Klass::layout_helper_needs_slow_path(layout_con);
3815     initial_slow_test = must_go_slow ? intcon(1) : extra_slow_test;
3816   } else {   // reflective case
3817     // This reflective path is used by Unsafe.allocateInstance.
3818     // (It may be stress-tested by specifying StressReflectiveCode.)
3819     // Basically, we want to get into the VM is there's an illegal argument.
3820     Node* bit = intcon(Klass::_lh_instance_slow_path_bit);
3821     initial_slow_test = _gvn.transform( new AndINode(layout_val, bit) );
3822     if (extra_slow_test != intcon(0)) {
3823       initial_slow_test = _gvn.transform( new OrINode(initial_slow_test, extra_slow_test) );
3824     }
3825     // (Macro-expander will further convert this to a Bool, if necessary.)
3826   }
3827 
3828   // Find the size in bytes.  This is easy; it's the layout_helper.
3829   // The size value must be valid even if the slow path is taken.
3830   Node* size = nullptr;
3831   if (layout_is_con) {
3832     size = MakeConX(Klass::layout_helper_size_in_bytes(layout_con));
3833   } else {   // reflective case
3834     // This reflective path is used by clone and Unsafe.allocateInstance.
3835     size = ConvI2X(layout_val);
3836 
3837     // Clear the low bits to extract layout_helper_size_in_bytes:
3838     assert((int)Klass::_lh_instance_slow_path_bit < BytesPerLong, "clear bit");
3839     Node* mask = MakeConX(~ (intptr_t)right_n_bits(LogBytesPerLong));
3840     size = _gvn.transform( new AndXNode(size, mask) );
3841   }
3842   if (return_size_val != nullptr) {
3843     (*return_size_val) = size;
3844   }
3845 
3846   // This is a precise notnull oop of the klass.
3847   // (Actually, it need not be precise if this is a reflective allocation.)
3848   // It's what we cast the result to.
3849   const TypeKlassPtr* tklass = _gvn.type(klass_node)->isa_klassptr();
3850   if (!tklass)  tklass = TypeInstKlassPtr::OBJECT;
3851   const TypeOopPtr* oop_type = tklass->as_instance_type();
3852 
3853   // Now generate allocation code
3854 
3855   // The entire memory state is needed for slow path of the allocation
3856   // since GC and deoptimization can happened.
3857   Node *mem = reset_memory();
3858   set_all_memory(mem); // Create new memory state
3859 
3860   AllocateNode* alloc = new AllocateNode(C, AllocateNode::alloc_type(Type::TOP),
3861                                          control(), mem, i_o(),
3862                                          size, klass_node,
3863                                          initial_slow_test);
3864 
3865   return set_output_for_allocation(alloc, oop_type, deoptimize_on_exception);
3866 }
3867 
3868 //-------------------------------new_array-------------------------------------
3869 // helper for both newarray and anewarray
3870 // The 'length' parameter is (obviously) the length of the array.
3871 // The optional arguments are for specialized use by intrinsics:
3872 //  - If 'return_size_val', report the non-padded array size (sum of header size
3873 //    and array body) to the caller.
3874 //  - deoptimize_on_exception controls how Java exceptions are handled (rethrow vs deoptimize)
3875 Node* GraphKit::new_array(Node* klass_node,     // array klass (maybe variable)
3876                           Node* length,         // number of array elements
3877                           int   nargs,          // number of arguments to push back for uncommon trap
3878                           Node* *return_size_val,
3879                           bool deoptimize_on_exception) {
3880   jint  layout_con = Klass::_lh_neutral_value;
3881   Node* layout_val = get_layout_helper(klass_node, layout_con);
3882   int   layout_is_con = (layout_val == nullptr);
3883 
3884   if (!layout_is_con && !StressReflectiveCode &&
3885       !too_many_traps(Deoptimization::Reason_class_check)) {
3886     // This is a reflective array creation site.
3887     // Optimistically assume that it is a subtype of Object[],
3888     // so that we can fold up all the address arithmetic.
3889     layout_con = Klass::array_layout_helper(T_OBJECT);
3890     Node* cmp_lh = _gvn.transform( new CmpINode(layout_val, intcon(layout_con)) );
3891     Node* bol_lh = _gvn.transform( new BoolNode(cmp_lh, BoolTest::eq) );
3892     { BuildCutout unless(this, bol_lh, PROB_MAX);
3893       inc_sp(nargs);
3894       uncommon_trap(Deoptimization::Reason_class_check,
3895                     Deoptimization::Action_maybe_recompile);
3896     }
3897     layout_val = nullptr;
3898     layout_is_con = true;
3899   }
3900 
3901   // Generate the initial go-slow test.  Make sure we do not overflow
3902   // if length is huge (near 2Gig) or negative!  We do not need
3903   // exact double-words here, just a close approximation of needed
3904   // double-words.  We can't add any offset or rounding bits, lest we
3905   // take a size -1 of bytes and make it positive.  Use an unsigned
3906   // compare, so negative sizes look hugely positive.
3907   int fast_size_limit = FastAllocateSizeLimit;
3908   if (layout_is_con) {
3909     assert(!StressReflectiveCode, "stress mode does not use these paths");
3910     // Increase the size limit if we have exact knowledge of array type.
3911     int log2_esize = Klass::layout_helper_log2_element_size(layout_con);
3912     assert(fast_size_limit == 0 || count_leading_zeros(fast_size_limit) > static_cast<unsigned>(LogBytesPerLong - log2_esize),
3913            "fast_size_limit (%d) overflow when shifted left by %d", fast_size_limit, LogBytesPerLong - log2_esize);
3914     fast_size_limit <<= (LogBytesPerLong - log2_esize);
3915   }
3916 
3917   Node* initial_slow_cmp  = _gvn.transform( new CmpUNode( length, intcon( fast_size_limit ) ) );
3918   Node* initial_slow_test = _gvn.transform( new BoolNode( initial_slow_cmp, BoolTest::gt ) );
3919 
3920   // --- Size Computation ---
3921   // array_size = round_to_heap(array_header + (length << elem_shift));
3922   // where round_to_heap(x) == align_to(x, MinObjAlignmentInBytes)
3923   // and align_to(x, y) == ((x + y-1) & ~(y-1))
3924   // The rounding mask is strength-reduced, if possible.
3925   int round_mask = MinObjAlignmentInBytes - 1;
3926   Node* header_size = nullptr;
3927   // (T_BYTE has the weakest alignment and size restrictions...)
3928   if (layout_is_con) {
3929     int       hsize  = Klass::layout_helper_header_size(layout_con);
3930     int       eshift = Klass::layout_helper_log2_element_size(layout_con);
3931     if ((round_mask & ~right_n_bits(eshift)) == 0)
3932       round_mask = 0;  // strength-reduce it if it goes away completely
3933     assert((hsize & right_n_bits(eshift)) == 0, "hsize is pre-rounded");
3934     int header_size_min = arrayOopDesc::base_offset_in_bytes(T_BYTE);
3935     assert(header_size_min <= hsize, "generic minimum is smallest");
3936     header_size = intcon(hsize);
3937   } else {
3938     Node* hss   = intcon(Klass::_lh_header_size_shift);
3939     Node* hsm   = intcon(Klass::_lh_header_size_mask);
3940     header_size = _gvn.transform(new URShiftINode(layout_val, hss));
3941     header_size = _gvn.transform(new AndINode(header_size, hsm));
3942   }
3943 
3944   Node* elem_shift = nullptr;
3945   if (layout_is_con) {
3946     int eshift = Klass::layout_helper_log2_element_size(layout_con);
3947     if (eshift != 0)
3948       elem_shift = intcon(eshift);
3949   } else {
3950     // There is no need to mask or shift this value.
3951     // The semantics of LShiftINode include an implicit mask to 0x1F.
3952     assert(Klass::_lh_log2_element_size_shift == 0, "use shift in place");
3953     elem_shift = layout_val;
3954   }
3955 
3956   // Transition to native address size for all offset calculations:
3957   Node* lengthx = ConvI2X(length);
3958   Node* headerx = ConvI2X(header_size);
3959 #ifdef _LP64
3960   { const TypeInt* tilen = _gvn.find_int_type(length);
3961     if (tilen != nullptr && tilen->_lo < 0) {
3962       // Add a manual constraint to a positive range.  Cf. array_element_address.
3963       jint size_max = fast_size_limit;
3964       if (size_max > tilen->_hi && tilen->_hi >= 0) {
3965         size_max = tilen->_hi;
3966       }
3967       const TypeInt* tlcon = TypeInt::make(0, size_max, Type::WidenMin);
3968 
3969       // Only do a narrow I2L conversion if the range check passed.
3970       IfNode* iff = new IfNode(control(), initial_slow_test, PROB_MIN, COUNT_UNKNOWN);
3971       _gvn.transform(iff);
3972       RegionNode* region = new RegionNode(3);
3973       _gvn.set_type(region, Type::CONTROL);
3974       lengthx = new PhiNode(region, TypeLong::LONG);
3975       _gvn.set_type(lengthx, TypeLong::LONG);
3976 
3977       // Range check passed. Use ConvI2L node with narrow type.
3978       Node* passed = IfFalse(iff);
3979       region->init_req(1, passed);
3980       // Make I2L conversion control dependent to prevent it from
3981       // floating above the range check during loop optimizations.
3982       lengthx->init_req(1, C->constrained_convI2L(&_gvn, length, tlcon, passed));
3983 
3984       // Range check failed. Use ConvI2L with wide type because length may be invalid.
3985       region->init_req(2, IfTrue(iff));
3986       lengthx->init_req(2, ConvI2X(length));
3987 
3988       set_control(region);
3989       record_for_igvn(region);
3990       record_for_igvn(lengthx);
3991     }
3992   }
3993 #endif
3994 
3995   // Combine header size and body size for the array copy part, then align (if
3996   // necessary) for the allocation part. This computation cannot overflow,
3997   // because it is used only in two places, one where the length is sharply
3998   // limited, and the other after a successful allocation.
3999   Node* abody = lengthx;
4000   if (elem_shift != nullptr) {
4001     abody = _gvn.transform(new LShiftXNode(lengthx, elem_shift));
4002   }
4003   Node* non_rounded_size = _gvn.transform(new AddXNode(headerx, abody));
4004 
4005   if (return_size_val != nullptr) {
4006     // This is the size
4007     (*return_size_val) = non_rounded_size;
4008   }
4009 
4010   Node* size = non_rounded_size;
4011   if (round_mask != 0) {
4012     Node* mask1 = MakeConX(round_mask);
4013     size = _gvn.transform(new AddXNode(size, mask1));
4014     Node* mask2 = MakeConX(~round_mask);
4015     size = _gvn.transform(new AndXNode(size, mask2));
4016   }
4017   // else if round_mask == 0, the size computation is self-rounding
4018 
4019   // Now generate allocation code
4020 
4021   // The entire memory state is needed for slow path of the allocation
4022   // since GC and deoptimization can happened.
4023   Node *mem = reset_memory();
4024   set_all_memory(mem); // Create new memory state
4025 
4026   if (initial_slow_test->is_Bool()) {
4027     // Hide it behind a CMoveI, or else PhaseIdealLoop::split_up will get sick.
4028     initial_slow_test = initial_slow_test->as_Bool()->as_int_value(&_gvn);
4029   }
4030 
4031   const TypeOopPtr* ary_type = _gvn.type(klass_node)->is_klassptr()->as_instance_type();
4032   Node* valid_length_test = _gvn.intcon(1);
4033   if (ary_type->isa_aryptr()) {
4034     BasicType bt = ary_type->isa_aryptr()->elem()->array_element_basic_type();
4035     jint max = TypeAryPtr::max_array_length(bt);
4036     Node* valid_length_cmp  = _gvn.transform(new CmpUNode(length, intcon(max)));
4037     valid_length_test = _gvn.transform(new BoolNode(valid_length_cmp, BoolTest::le));
4038   }
4039 
4040   // Create the AllocateArrayNode and its result projections
4041   AllocateArrayNode* alloc
4042     = new AllocateArrayNode(C, AllocateArrayNode::alloc_type(TypeInt::INT),
4043                             control(), mem, i_o(),
4044                             size, klass_node,
4045                             initial_slow_test,
4046                             length, valid_length_test);
4047 
4048   // Cast to correct type.  Note that the klass_node may be constant or not,
4049   // and in the latter case the actual array type will be inexact also.
4050   // (This happens via a non-constant argument to inline_native_newArray.)
4051   // In any case, the value of klass_node provides the desired array type.
4052   const TypeInt* length_type = _gvn.find_int_type(length);
4053   if (ary_type->isa_aryptr() && length_type != nullptr) {
4054     // Try to get a better type than POS for the size
4055     ary_type = ary_type->is_aryptr()->cast_to_size(length_type);
4056   }
4057 
4058   Node* javaoop = set_output_for_allocation(alloc, ary_type, deoptimize_on_exception);
4059 
4060   array_ideal_length(alloc, ary_type, true);
4061   return javaoop;
4062 }
4063 
4064 // The following "Ideal_foo" functions are placed here because they recognize
4065 // the graph shapes created by the functions immediately above.
4066 
4067 //---------------------------Ideal_allocation----------------------------------
4068 // Given an oop pointer or raw pointer, see if it feeds from an AllocateNode.
4069 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr) {
4070   if (ptr == nullptr) {     // reduce dumb test in callers
4071     return nullptr;
4072   }
4073 
4074   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
4075   ptr = bs->step_over_gc_barrier(ptr);
4076 
4077   if (ptr->is_CheckCastPP()) { // strip only one raw-to-oop cast
4078     ptr = ptr->in(1);
4079     if (ptr == nullptr) return nullptr;
4080   }
4081   // Return null for allocations with several casts:
4082   //   j.l.reflect.Array.newInstance(jobject, jint)
4083   //   Object.clone()
4084   // to keep more precise type from last cast.
4085   if (ptr->is_Proj()) {
4086     Node* allo = ptr->in(0);
4087     if (allo != nullptr && allo->is_Allocate()) {
4088       return allo->as_Allocate();
4089     }
4090   }
4091   // Report failure to match.
4092   return nullptr;
4093 }
4094 
4095 // Fancy version which also strips off an offset (and reports it to caller).
4096 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseValues* phase,
4097                                              intptr_t& offset) {
4098   Node* base = AddPNode::Ideal_base_and_offset(ptr, phase, offset);
4099   if (base == nullptr)  return nullptr;
4100   return Ideal_allocation(base);
4101 }
4102 
4103 // Trace Initialize <- Proj[Parm] <- Allocate
4104 AllocateNode* InitializeNode::allocation() {
4105   Node* rawoop = in(InitializeNode::RawAddress);
4106   if (rawoop->is_Proj()) {
4107     Node* alloc = rawoop->in(0);
4108     if (alloc->is_Allocate()) {
4109       return alloc->as_Allocate();
4110     }
4111   }
4112   return nullptr;
4113 }
4114 
4115 // Trace Allocate -> Proj[Parm] -> Initialize
4116 InitializeNode* AllocateNode::initialization() {
4117   ProjNode* rawoop = proj_out_or_null(AllocateNode::RawAddress);
4118   if (rawoop == nullptr)  return nullptr;
4119   for (DUIterator_Fast imax, i = rawoop->fast_outs(imax); i < imax; i++) {
4120     Node* init = rawoop->fast_out(i);
4121     if (init->is_Initialize()) {
4122       assert(init->as_Initialize()->allocation() == this, "2-way link");
4123       return init->as_Initialize();
4124     }
4125   }
4126   return nullptr;
4127 }
4128 
4129 // Add a Parse Predicate with an uncommon trap on the failing/false path. Normal control will continue on the true path.
4130 void GraphKit::add_parse_predicate(Deoptimization::DeoptReason reason, const int nargs) {
4131   // Too many traps seen?
4132   if (too_many_traps(reason)) {
4133 #ifdef ASSERT
4134     if (TraceLoopPredicate) {
4135       int tc = C->trap_count(reason);
4136       tty->print("too many traps=%s tcount=%d in ",
4137                     Deoptimization::trap_reason_name(reason), tc);
4138       method()->print(); // which method has too many predicate traps
4139       tty->cr();
4140     }
4141 #endif
4142     // We cannot afford to take more traps here,
4143     // do not generate Parse Predicate.
4144     return;
4145   }
4146 
4147   ParsePredicateNode* parse_predicate = new ParsePredicateNode(control(), reason, &_gvn);
4148   _gvn.set_type(parse_predicate, parse_predicate->Value(&_gvn));
4149   Node* if_false = _gvn.transform(new IfFalseNode(parse_predicate));
4150   {
4151     PreserveJVMState pjvms(this);
4152     set_control(if_false);
4153     inc_sp(nargs);
4154     uncommon_trap(reason, Deoptimization::Action_maybe_recompile);
4155   }
4156   Node* if_true = _gvn.transform(new IfTrueNode(parse_predicate));
4157   set_control(if_true);
4158 }
4159 
4160 // Add Parse Predicates which serve as placeholders to create new Runtime Predicates above them. All
4161 // Runtime Predicates inside a Runtime Predicate block share the same uncommon trap as the Parse Predicate.
4162 void GraphKit::add_parse_predicates(int nargs) {
4163   if (ShortRunningLongLoop) {
4164     // Will narrow the limit down with a cast node. Predicates added later may depend on the cast so should be last when
4165     // walking up from the loop.
4166     add_parse_predicate(Deoptimization::Reason_short_running_long_loop, nargs);
4167   }
4168   if (UseLoopPredicate) {
4169     add_parse_predicate(Deoptimization::Reason_predicate, nargs);
4170     if (UseProfiledLoopPredicate) {
4171       add_parse_predicate(Deoptimization::Reason_profile_predicate, nargs);
4172     }
4173   }
4174   if (UseAutoVectorizationPredicate) {
4175     add_parse_predicate(Deoptimization::Reason_auto_vectorization_check, nargs);
4176   }
4177   // Loop Limit Check Predicate should be near the loop.
4178   add_parse_predicate(Deoptimization::Reason_loop_limit_check, nargs);
4179 }
4180 
4181 void GraphKit::sync_kit(IdealKit& ideal) {
4182   set_all_memory(ideal.merged_memory());
4183   set_i_o(ideal.i_o());
4184   set_control(ideal.ctrl());
4185 }
4186 
4187 void GraphKit::final_sync(IdealKit& ideal) {
4188   // Final sync IdealKit and graphKit.
4189   sync_kit(ideal);
4190 }
4191 
4192 Node* GraphKit::load_String_length(Node* str, bool set_ctrl) {
4193   Node* len = load_array_length(load_String_value(str, set_ctrl));
4194   Node* coder = load_String_coder(str, set_ctrl);
4195   // Divide length by 2 if coder is UTF16
4196   return _gvn.transform(new RShiftINode(len, coder));
4197 }
4198 
4199 Node* GraphKit::load_String_value(Node* str, bool set_ctrl) {
4200   int value_offset = java_lang_String::value_offset();
4201   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4202                                                      false, nullptr, 0);
4203   const TypePtr* value_field_type = string_type->add_offset(value_offset);
4204   const TypeAryPtr* value_type = TypeAryPtr::make(TypePtr::BotPTR,
4205                                                   TypeAry::make(TypeInt::BYTE, TypeInt::POS),
4206                                                   ciTypeArrayKlass::make(T_BYTE), true, 0);
4207   Node* p = basic_plus_adr(str, str, value_offset);
4208   Node* load = access_load_at(str, p, value_field_type, value_type, T_OBJECT,
4209                               IN_HEAP | (set_ctrl ? C2_CONTROL_DEPENDENT_LOAD : 0) | MO_UNORDERED);
4210   return must_be_not_null(load, true);
4211 }
4212 
4213 Node* GraphKit::load_String_coder(Node* str, bool set_ctrl) {
4214   if (!CompactStrings) {
4215     return intcon(java_lang_String::CODER_UTF16);
4216   }
4217   int coder_offset = java_lang_String::coder_offset();
4218   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4219                                                      false, nullptr, 0);
4220   const TypePtr* coder_field_type = string_type->add_offset(coder_offset);
4221 
4222   Node* p = basic_plus_adr(str, str, coder_offset);
4223   Node* load = access_load_at(str, p, coder_field_type, TypeInt::BYTE, T_BYTE,
4224                               IN_HEAP | (set_ctrl ? C2_CONTROL_DEPENDENT_LOAD : 0) | MO_UNORDERED);
4225   return load;
4226 }
4227 
4228 void GraphKit::store_String_value(Node* str, Node* value) {
4229   int value_offset = java_lang_String::value_offset();
4230   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4231                                                      false, nullptr, 0);
4232   const TypePtr* value_field_type = string_type->add_offset(value_offset);
4233 
4234   access_store_at(str,  basic_plus_adr(str, value_offset), value_field_type,
4235                   value, TypeAryPtr::BYTES, T_OBJECT, IN_HEAP | MO_UNORDERED);
4236 }
4237 
4238 void GraphKit::store_String_coder(Node* str, Node* value) {
4239   int coder_offset = java_lang_String::coder_offset();
4240   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4241                                                      false, nullptr, 0);
4242   const TypePtr* coder_field_type = string_type->add_offset(coder_offset);
4243 
4244   access_store_at(str, basic_plus_adr(str, coder_offset), coder_field_type,
4245                   value, TypeInt::BYTE, T_BYTE, IN_HEAP | MO_UNORDERED);
4246 }
4247 
4248 // If input and output memory types differ, capture the whole memory to preserve
4249 // the dependency between preceding and subsequent loads/stores.
4250 // For example, the following program:
4251 //  StoreB
4252 //  compress_string
4253 //  LoadB
4254 // has this memory graph (use->def):
4255 //  LoadB -> compress_string -> CharMem
4256 //             ... -> StoreB -> ByteMem
4257 // The intrinsic hides the dependency between LoadB and StoreB, causing
4258 // the load to read from memory not containing the result of the StoreB.
4259 // The correct memory graph should look like this:
4260 //  LoadB -> compress_string -> MergeMem -> StoreB
4261 Node* GraphKit::capture_memory(const TypePtr*& combined_type, const TypePtr* src_type, const TypePtr* dst_type) {
4262   if (src_type == dst_type) {
4263     // Types are equal, we don't need a MergeMemNode
4264     combined_type = src_type;
4265     return memory(src_type);
4266   }
4267   Node* mem = reset_memory();
4268   set_all_memory(mem);
4269   combined_type = TypePtr::BOTTOM;
4270   return mem;
4271 }
4272 
4273 // If dst_type and src_type are different, str may have an anti-dependency with another node
4274 // consuming src_type.
4275 // For example:
4276 //  compress_string
4277 //  StoreC
4278 // has this memory graph (use->def):
4279 //  compress_string -> MergeMem -> CharMem
4280 //                       StoreC
4281 // The scheduler needs to ensure that compress_string is not executed after StoreC, or it will read
4282 // the wrong memory. For normal loads, the scheduler computes its anti-dependencies to ensure the
4283 // memory it reads from is not killed. Since we do not compute anti-dependencies for
4284 // StrCompressedCopyNode, manually insert a MemBar so the anti-dependency becomes use-def
4285 // dependency:
4286 //  StoreC -> MemBar -> MergeMem -> compress_string -> MergeMem -> CharMem
4287 //                               -------------------------------->
4288 void GraphKit::memory_effect(Node* res_mem, const TypePtr* src_type, const TypePtr* dst_type) {
4289   set_memory(res_mem, dst_type);
4290   if (src_type != dst_type) {
4291     Node* all_mem = reset_memory();
4292     set_all_memory(all_mem);
4293     Node* membar = new MemBarCPUOrderNode(C, C->get_alias_index(src_type), nullptr);
4294     membar->init_req(TypeFunc::Control, control());
4295     membar->init_req(TypeFunc::Memory, all_mem);
4296     membar = _gvn.transform(membar);
4297     set_control(_gvn.transform(new ProjNode(membar, TypeFunc::Control)));
4298     set_memory(_gvn.transform(new ProjNode(membar, TypeFunc::Memory)), src_type);
4299   }
4300 }
4301 
4302 Node* GraphKit::compress_string(Node* src, const TypeAryPtr* src_type, Node* dst, Node* count) {
4303   assert(Matcher::match_rule_supported(Op_StrCompressedCopy), "Intrinsic not supported");
4304   assert(src_type == TypeAryPtr::BYTES || src_type == TypeAryPtr::CHARS, "invalid source type");
4305   const TypePtr* dst_type = TypeAryPtr::BYTES;
4306   const TypePtr* adr_type;
4307   Node* mem = capture_memory(adr_type, src_type, dst_type);
4308   StrCompressedCopyNode* str = new StrCompressedCopyNode(control(), mem, adr_type, src, dst, count);
4309   Node* res_mem = _gvn.transform(new SCMemProjNode(_gvn.transform(str)));
4310   memory_effect(res_mem, src_type, dst_type);
4311   return str;
4312 }
4313 
4314 void GraphKit::inflate_string(Node* src, Node* dst, const TypeAryPtr* dst_type, Node* count) {
4315   assert(Matcher::match_rule_supported(Op_StrInflatedCopy), "Intrinsic not supported");
4316   assert(dst_type == TypeAryPtr::BYTES || dst_type == TypeAryPtr::CHARS, "invalid dest type");
4317   const TypePtr* src_type = TypeAryPtr::BYTES;
4318   const TypePtr* adr_type;
4319   Node* mem = capture_memory(adr_type, src_type, dst_type);
4320   StrInflatedCopyNode* str = new StrInflatedCopyNode(control(), mem, adr_type, src, dst, count);
4321   Node* res_mem = _gvn.transform(str);
4322   memory_effect(res_mem, src_type, dst_type);
4323 }
4324 
4325 void GraphKit::inflate_string_slow(Node* src, Node* dst, Node* start, Node* count) {
4326   /**
4327    * int i_char = start;
4328    * for (int i_byte = 0; i_byte < count; i_byte++) {
4329    *   dst[i_char++] = (char)(src[i_byte] & 0xff);
4330    * }
4331    */
4332   add_parse_predicates();
4333   C->set_has_loops(true);
4334 
4335   RegionNode* head = new RegionNode(3);
4336   head->init_req(1, control());
4337   gvn().set_type(head, Type::CONTROL);
4338   record_for_igvn(head);
4339 
4340   Node* i_byte = new PhiNode(head, TypeInt::INT);
4341   i_byte->init_req(1, intcon(0));
4342   gvn().set_type(i_byte, TypeInt::INT);
4343   record_for_igvn(i_byte);
4344 
4345   Node* i_char = new PhiNode(head, TypeInt::INT);
4346   i_char->init_req(1, start);
4347   gvn().set_type(i_char, TypeInt::INT);
4348   record_for_igvn(i_char);
4349 
4350   Node* mem = PhiNode::make(head, memory(TypeAryPtr::BYTES), Type::MEMORY, TypeAryPtr::BYTES);
4351   gvn().set_type(mem, Type::MEMORY);
4352   record_for_igvn(mem);
4353   set_control(head);
4354   set_memory(mem, TypeAryPtr::BYTES);
4355   Node* ch = load_array_element(src, i_byte, TypeAryPtr::BYTES, /* set_ctrl */ true);
4356   Node* st = store_to_memory(control(), array_element_address(dst, i_char, T_BYTE),
4357                              AndI(ch, intcon(0xff)), T_CHAR, MemNode::unordered, false,
4358                              false, true /* mismatched */);
4359 
4360   IfNode* iff = create_and_map_if(head, Bool(CmpI(i_byte, count), BoolTest::lt), PROB_FAIR, COUNT_UNKNOWN);
4361   head->init_req(2, IfTrue(iff));
4362   mem->init_req(2, st);
4363   i_byte->init_req(2, AddI(i_byte, intcon(1)));
4364   i_char->init_req(2, AddI(i_char, intcon(2)));
4365 
4366   set_control(IfFalse(iff));
4367   set_memory(st, TypeAryPtr::BYTES);
4368 }
4369 
4370 Node* GraphKit::make_constant_from_field(ciField* field, Node* obj) {
4371   if (!field->is_constant()) {
4372     return nullptr; // Field not marked as constant.
4373   }
4374   ciInstance* holder = nullptr;
4375   if (!field->is_static()) {
4376     ciObject* const_oop = obj->bottom_type()->is_oopptr()->const_oop();
4377     if (const_oop != nullptr && const_oop->is_instance()) {
4378       holder = const_oop->as_instance();
4379     }
4380   }
4381   const Type* con_type = Type::make_constant_from_field(field, holder, field->layout_type(),
4382                                                         /*is_unsigned_load=*/false);
4383   if (con_type != nullptr) {
4384     return makecon(con_type);
4385   }
4386   return nullptr;
4387 }
4388 
4389 Node* GraphKit::maybe_narrow_object_type(Node* obj, ciKlass* type) {
4390   const TypeOopPtr* obj_type = obj->bottom_type()->isa_oopptr();
4391   const TypeOopPtr* sig_type = TypeOopPtr::make_from_klass(type);
4392   if (obj_type != nullptr && sig_type->is_loaded() && !obj_type->higher_equal(sig_type)) {
4393     const Type* narrow_obj_type = obj_type->filter_speculative(sig_type); // keep speculative part
4394     Node* casted_obj = gvn().transform(new CheckCastPPNode(control(), obj, narrow_obj_type));
4395     return casted_obj;
4396   }
4397   return obj;
4398 }