1 /*
   2  * Copyright (c) 2001, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "ci/ciUtilities.hpp"
  27 #include "compiler/compileLog.hpp"
  28 #include "gc/shared/barrierSet.hpp"
  29 #include "gc/shared/c2/barrierSetC2.hpp"
  30 #include "interpreter/interpreter.hpp"
  31 #include "memory/resourceArea.hpp"
  32 #include "opto/addnode.hpp"
  33 #include "opto/castnode.hpp"
  34 #include "opto/convertnode.hpp"
  35 #include "opto/graphKit.hpp"
  36 #include "opto/idealKit.hpp"
  37 #include "opto/intrinsicnode.hpp"
  38 #include "opto/locknode.hpp"
  39 #include "opto/machnode.hpp"
  40 #include "opto/opaquenode.hpp"
  41 #include "opto/parse.hpp"
  42 #include "opto/rootnode.hpp"
  43 #include "opto/runtime.hpp"
  44 #include "runtime/deoptimization.hpp"
  45 #include "runtime/sharedRuntime.hpp"
  46 #include "utilities/macros.hpp"
  47 #if INCLUDE_SHENANDOAHGC
  48 #include "gc/shenandoah/c2/shenandoahBarrierSetC2.hpp"
  49 #endif
  50 
  51 //----------------------------GraphKit-----------------------------------------
  52 // Main utility constructor.
  53 GraphKit::GraphKit(JVMState* jvms)
  54   : Phase(Phase::Parser),
  55     _env(C->env()),
  56     _gvn(*C->initial_gvn()),
  57     _barrier_set(BarrierSet::barrier_set()->barrier_set_c2())
  58 {
  59   _exceptions = jvms->map()->next_exception();
  60   if (_exceptions != NULL)  jvms->map()->set_next_exception(NULL);
  61   set_jvms(jvms);
  62 }
  63 
  64 // Private constructor for parser.
  65 GraphKit::GraphKit()
  66   : Phase(Phase::Parser),
  67     _env(C->env()),
  68     _gvn(*C->initial_gvn()),
  69     _barrier_set(BarrierSet::barrier_set()->barrier_set_c2())
  70 {
  71   _exceptions = NULL;
  72   set_map(NULL);
  73   debug_only(_sp = -99);
  74   debug_only(set_bci(-99));
  75 }
  76 
  77 
  78 
  79 //---------------------------clean_stack---------------------------------------
  80 // Clear away rubbish from the stack area of the JVM state.
  81 // This destroys any arguments that may be waiting on the stack.
  82 void GraphKit::clean_stack(int from_sp) {
  83   SafePointNode* map      = this->map();
  84   JVMState*      jvms     = this->jvms();
  85   int            stk_size = jvms->stk_size();
  86   int            stkoff   = jvms->stkoff();
  87   Node*          top      = this->top();
  88   for (int i = from_sp; i < stk_size; i++) {
  89     if (map->in(stkoff + i) != top) {
  90       map->set_req(stkoff + i, top);
  91     }
  92   }
  93 }
  94 
  95 
  96 //--------------------------------sync_jvms-----------------------------------
  97 // Make sure our current jvms agrees with our parse state.
  98 JVMState* GraphKit::sync_jvms() const {
  99   JVMState* jvms = this->jvms();
 100   jvms->set_bci(bci());       // Record the new bci in the JVMState
 101   jvms->set_sp(sp());         // Record the new sp in the JVMState
 102   assert(jvms_in_sync(), "jvms is now in sync");
 103   return jvms;
 104 }
 105 
 106 //--------------------------------sync_jvms_for_reexecute---------------------
 107 // Make sure our current jvms agrees with our parse state.  This version
 108 // uses the reexecute_sp for reexecuting bytecodes.
 109 JVMState* GraphKit::sync_jvms_for_reexecute() {
 110   JVMState* jvms = this->jvms();
 111   jvms->set_bci(bci());          // Record the new bci in the JVMState
 112   jvms->set_sp(reexecute_sp());  // Record the new sp in the JVMState
 113   return jvms;
 114 }
 115 
 116 #ifdef ASSERT
 117 bool GraphKit::jvms_in_sync() const {
 118   Parse* parse = is_Parse();
 119   if (parse == NULL) {
 120     if (bci() !=      jvms()->bci())          return false;
 121     if (sp()  != (int)jvms()->sp())           return false;
 122     return true;
 123   }
 124   if (jvms()->method() != parse->method())    return false;
 125   if (jvms()->bci()    != parse->bci())       return false;
 126   int jvms_sp = jvms()->sp();
 127   if (jvms_sp          != parse->sp())        return false;
 128   int jvms_depth = jvms()->depth();
 129   if (jvms_depth       != parse->depth())     return false;
 130   return true;
 131 }
 132 
 133 // Local helper checks for special internal merge points
 134 // used to accumulate and merge exception states.
 135 // They are marked by the region's in(0) edge being the map itself.
 136 // Such merge points must never "escape" into the parser at large,
 137 // until they have been handed to gvn.transform.
 138 static bool is_hidden_merge(Node* reg) {
 139   if (reg == NULL)  return false;
 140   if (reg->is_Phi()) {
 141     reg = reg->in(0);
 142     if (reg == NULL)  return false;
 143   }
 144   return reg->is_Region() && reg->in(0) != NULL && reg->in(0)->is_Root();
 145 }
 146 
 147 void GraphKit::verify_map() const {
 148   if (map() == NULL)  return;  // null map is OK
 149   assert(map()->req() <= jvms()->endoff(), "no extra garbage on map");
 150   assert(!map()->has_exceptions(),    "call add_exception_states_from 1st");
 151   assert(!is_hidden_merge(control()), "call use_exception_state, not set_map");
 152 }
 153 
 154 void GraphKit::verify_exception_state(SafePointNode* ex_map) {
 155   assert(ex_map->next_exception() == NULL, "not already part of a chain");
 156   assert(has_saved_ex_oop(ex_map), "every exception state has an ex_oop");
 157 }
 158 #endif
 159 
 160 //---------------------------stop_and_kill_map---------------------------------
 161 // Set _map to NULL, signalling a stop to further bytecode execution.
 162 // First smash the current map's control to a constant, to mark it dead.
 163 void GraphKit::stop_and_kill_map() {
 164   SafePointNode* dead_map = stop();
 165   if (dead_map != NULL) {
 166     dead_map->disconnect_inputs(NULL, C); // Mark the map as killed.
 167     assert(dead_map->is_killed(), "must be so marked");
 168   }
 169 }
 170 
 171 
 172 //--------------------------------stopped--------------------------------------
 173 // Tell if _map is NULL, or control is top.
 174 bool GraphKit::stopped() {
 175   if (map() == NULL)           return true;
 176   else if (control() == top()) return true;
 177   else                         return false;
 178 }
 179 
 180 
 181 //-----------------------------has_ex_handler----------------------------------
 182 // Tell if this method or any caller method has exception handlers.
 183 bool GraphKit::has_ex_handler() {
 184   for (JVMState* jvmsp = jvms(); jvmsp != NULL; jvmsp = jvmsp->caller()) {
 185     if (jvmsp->has_method() && jvmsp->method()->has_exception_handlers()) {
 186       return true;
 187     }
 188   }
 189   return false;
 190 }
 191 
 192 //------------------------------save_ex_oop------------------------------------
 193 // Save an exception without blowing stack contents or other JVM state.
 194 void GraphKit::set_saved_ex_oop(SafePointNode* ex_map, Node* ex_oop) {
 195   assert(!has_saved_ex_oop(ex_map), "clear ex-oop before setting again");
 196   ex_map->add_req(ex_oop);
 197   debug_only(verify_exception_state(ex_map));
 198 }
 199 
 200 inline static Node* common_saved_ex_oop(SafePointNode* ex_map, bool clear_it) {
 201   assert(GraphKit::has_saved_ex_oop(ex_map), "ex_oop must be there");
 202   Node* ex_oop = ex_map->in(ex_map->req()-1);
 203   if (clear_it)  ex_map->del_req(ex_map->req()-1);
 204   return ex_oop;
 205 }
 206 
 207 //-----------------------------saved_ex_oop------------------------------------
 208 // Recover a saved exception from its map.
 209 Node* GraphKit::saved_ex_oop(SafePointNode* ex_map) {
 210   return common_saved_ex_oop(ex_map, false);
 211 }
 212 
 213 //--------------------------clear_saved_ex_oop---------------------------------
 214 // Erase a previously saved exception from its map.
 215 Node* GraphKit::clear_saved_ex_oop(SafePointNode* ex_map) {
 216   return common_saved_ex_oop(ex_map, true);
 217 }
 218 
 219 #ifdef ASSERT
 220 //---------------------------has_saved_ex_oop----------------------------------
 221 // Erase a previously saved exception from its map.
 222 bool GraphKit::has_saved_ex_oop(SafePointNode* ex_map) {
 223   return ex_map->req() == ex_map->jvms()->endoff()+1;
 224 }
 225 #endif
 226 
 227 //-------------------------make_exception_state--------------------------------
 228 // Turn the current JVM state into an exception state, appending the ex_oop.
 229 SafePointNode* GraphKit::make_exception_state(Node* ex_oop) {
 230   sync_jvms();
 231   SafePointNode* ex_map = stop();  // do not manipulate this map any more
 232   set_saved_ex_oop(ex_map, ex_oop);
 233   return ex_map;
 234 }
 235 
 236 
 237 //--------------------------add_exception_state--------------------------------
 238 // Add an exception to my list of exceptions.
 239 void GraphKit::add_exception_state(SafePointNode* ex_map) {
 240   if (ex_map == NULL || ex_map->control() == top()) {
 241     return;
 242   }
 243 #ifdef ASSERT
 244   verify_exception_state(ex_map);
 245   if (has_exceptions()) {
 246     assert(ex_map->jvms()->same_calls_as(_exceptions->jvms()), "all collected exceptions must come from the same place");
 247   }
 248 #endif
 249 
 250   // If there is already an exception of exactly this type, merge with it.
 251   // In particular, null-checks and other low-level exceptions common up here.
 252   Node*       ex_oop  = saved_ex_oop(ex_map);
 253   const Type* ex_type = _gvn.type(ex_oop);
 254   if (ex_oop == top()) {
 255     // No action needed.
 256     return;
 257   }
 258   assert(ex_type->isa_instptr(), "exception must be an instance");
 259   for (SafePointNode* e2 = _exceptions; e2 != NULL; e2 = e2->next_exception()) {
 260     const Type* ex_type2 = _gvn.type(saved_ex_oop(e2));
 261     // We check sp also because call bytecodes can generate exceptions
 262     // both before and after arguments are popped!
 263     if (ex_type2 == ex_type
 264         && e2->_jvms->sp() == ex_map->_jvms->sp()) {
 265       combine_exception_states(ex_map, e2);
 266       return;
 267     }
 268   }
 269 
 270   // No pre-existing exception of the same type.  Chain it on the list.
 271   push_exception_state(ex_map);
 272 }
 273 
 274 //-----------------------add_exception_states_from-----------------------------
 275 void GraphKit::add_exception_states_from(JVMState* jvms) {
 276   SafePointNode* ex_map = jvms->map()->next_exception();
 277   if (ex_map != NULL) {
 278     jvms->map()->set_next_exception(NULL);
 279     for (SafePointNode* next_map; ex_map != NULL; ex_map = next_map) {
 280       next_map = ex_map->next_exception();
 281       ex_map->set_next_exception(NULL);
 282       add_exception_state(ex_map);
 283     }
 284   }
 285 }
 286 
 287 //-----------------------transfer_exceptions_into_jvms-------------------------
 288 JVMState* GraphKit::transfer_exceptions_into_jvms() {
 289   if (map() == NULL) {
 290     // We need a JVMS to carry the exceptions, but the map has gone away.
 291     // Create a scratch JVMS, cloned from any of the exception states...
 292     if (has_exceptions()) {
 293       _map = _exceptions;
 294       _map = clone_map();
 295       _map->set_next_exception(NULL);
 296       clear_saved_ex_oop(_map);
 297       debug_only(verify_map());
 298     } else {
 299       // ...or created from scratch
 300       JVMState* jvms = new (C) JVMState(_method, NULL);
 301       jvms->set_bci(_bci);
 302       jvms->set_sp(_sp);
 303       jvms->set_map(new SafePointNode(TypeFunc::Parms, jvms));
 304       set_jvms(jvms);
 305       for (uint i = 0; i < map()->req(); i++)  map()->init_req(i, top());
 306       set_all_memory(top());
 307       while (map()->req() < jvms->endoff())  map()->add_req(top());
 308     }
 309     // (This is a kludge, in case you didn't notice.)
 310     set_control(top());
 311   }
 312   JVMState* jvms = sync_jvms();
 313   assert(!jvms->map()->has_exceptions(), "no exceptions on this map yet");
 314   jvms->map()->set_next_exception(_exceptions);
 315   _exceptions = NULL;   // done with this set of exceptions
 316   return jvms;
 317 }
 318 
 319 static inline void add_n_reqs(Node* dstphi, Node* srcphi) {
 320   assert(is_hidden_merge(dstphi), "must be a special merge node");
 321   assert(is_hidden_merge(srcphi), "must be a special merge node");
 322   uint limit = srcphi->req();
 323   for (uint i = PhiNode::Input; i < limit; i++) {
 324     dstphi->add_req(srcphi->in(i));
 325   }
 326 }
 327 static inline void add_one_req(Node* dstphi, Node* src) {
 328   assert(is_hidden_merge(dstphi), "must be a special merge node");
 329   assert(!is_hidden_merge(src), "must not be a special merge node");
 330   dstphi->add_req(src);
 331 }
 332 
 333 //-----------------------combine_exception_states------------------------------
 334 // This helper function combines exception states by building phis on a
 335 // specially marked state-merging region.  These regions and phis are
 336 // untransformed, and can build up gradually.  The region is marked by
 337 // having a control input of its exception map, rather than NULL.  Such
 338 // regions do not appear except in this function, and in use_exception_state.
 339 void GraphKit::combine_exception_states(SafePointNode* ex_map, SafePointNode* phi_map) {
 340   if (failing())  return;  // dying anyway...
 341   JVMState* ex_jvms = ex_map->_jvms;
 342   assert(ex_jvms->same_calls_as(phi_map->_jvms), "consistent call chains");
 343   assert(ex_jvms->stkoff() == phi_map->_jvms->stkoff(), "matching locals");
 344   assert(ex_jvms->sp() == phi_map->_jvms->sp(), "matching stack sizes");
 345   assert(ex_jvms->monoff() == phi_map->_jvms->monoff(), "matching JVMS");
 346   assert(ex_jvms->scloff() == phi_map->_jvms->scloff(), "matching scalar replaced objects");
 347   assert(ex_map->req() == phi_map->req(), "matching maps");
 348   uint tos = ex_jvms->stkoff() + ex_jvms->sp();
 349   Node*         hidden_merge_mark = root();
 350   Node*         region  = phi_map->control();
 351   MergeMemNode* phi_mem = phi_map->merged_memory();
 352   MergeMemNode* ex_mem  = ex_map->merged_memory();
 353   if (region->in(0) != hidden_merge_mark) {
 354     // The control input is not (yet) a specially-marked region in phi_map.
 355     // Make it so, and build some phis.
 356     region = new RegionNode(2);
 357     _gvn.set_type(region, Type::CONTROL);
 358     region->set_req(0, hidden_merge_mark);  // marks an internal ex-state
 359     region->init_req(1, phi_map->control());
 360     phi_map->set_control(region);
 361     Node* io_phi = PhiNode::make(region, phi_map->i_o(), Type::ABIO);
 362     record_for_igvn(io_phi);
 363     _gvn.set_type(io_phi, Type::ABIO);
 364     phi_map->set_i_o(io_phi);
 365     for (MergeMemStream mms(phi_mem); mms.next_non_empty(); ) {
 366       Node* m = mms.memory();
 367       Node* m_phi = PhiNode::make(region, m, Type::MEMORY, mms.adr_type(C));
 368       record_for_igvn(m_phi);
 369       _gvn.set_type(m_phi, Type::MEMORY);
 370       mms.set_memory(m_phi);
 371     }
 372   }
 373 
 374   // Either or both of phi_map and ex_map might already be converted into phis.
 375   Node* ex_control = ex_map->control();
 376   // if there is special marking on ex_map also, we add multiple edges from src
 377   bool add_multiple = (ex_control->in(0) == hidden_merge_mark);
 378   // how wide was the destination phi_map, originally?
 379   uint orig_width = region->req();
 380 
 381   if (add_multiple) {
 382     add_n_reqs(region, ex_control);
 383     add_n_reqs(phi_map->i_o(), ex_map->i_o());
 384   } else {
 385     // ex_map has no merges, so we just add single edges everywhere
 386     add_one_req(region, ex_control);
 387     add_one_req(phi_map->i_o(), ex_map->i_o());
 388   }
 389   for (MergeMemStream mms(phi_mem, ex_mem); mms.next_non_empty2(); ) {
 390     if (mms.is_empty()) {
 391       // get a copy of the base memory, and patch some inputs into it
 392       const TypePtr* adr_type = mms.adr_type(C);
 393       Node* phi = mms.force_memory()->as_Phi()->slice_memory(adr_type);
 394       assert(phi->as_Phi()->region() == mms.base_memory()->in(0), "");
 395       mms.set_memory(phi);
 396       // Prepare to append interesting stuff onto the newly sliced phi:
 397       while (phi->req() > orig_width)  phi->del_req(phi->req()-1);
 398     }
 399     // Append stuff from ex_map:
 400     if (add_multiple) {
 401       add_n_reqs(mms.memory(), mms.memory2());
 402     } else {
 403       add_one_req(mms.memory(), mms.memory2());
 404     }
 405   }
 406   uint limit = ex_map->req();
 407   for (uint i = TypeFunc::Parms; i < limit; i++) {
 408     // Skip everything in the JVMS after tos.  (The ex_oop follows.)
 409     if (i == tos)  i = ex_jvms->monoff();
 410     Node* src = ex_map->in(i);
 411     Node* dst = phi_map->in(i);
 412     if (src != dst) {
 413       PhiNode* phi;
 414       if (dst->in(0) != region) {
 415         dst = phi = PhiNode::make(region, dst, _gvn.type(dst));
 416         record_for_igvn(phi);
 417         _gvn.set_type(phi, phi->type());
 418         phi_map->set_req(i, dst);
 419         // Prepare to append interesting stuff onto the new phi:
 420         while (dst->req() > orig_width)  dst->del_req(dst->req()-1);
 421       } else {
 422         assert(dst->is_Phi(), "nobody else uses a hidden region");
 423         phi = dst->as_Phi();
 424       }
 425       if (add_multiple && src->in(0) == ex_control) {
 426         // Both are phis.
 427         add_n_reqs(dst, src);
 428       } else {
 429         while (dst->req() < region->req())  add_one_req(dst, src);
 430       }
 431       const Type* srctype = _gvn.type(src);
 432       if (phi->type() != srctype) {
 433         const Type* dsttype = phi->type()->meet_speculative(srctype);
 434         if (phi->type() != dsttype) {
 435           phi->set_type(dsttype);
 436           _gvn.set_type(phi, dsttype);
 437         }
 438       }
 439     }
 440   }
 441   phi_map->merge_replaced_nodes_with(ex_map);
 442 }
 443 
 444 //--------------------------use_exception_state--------------------------------
 445 Node* GraphKit::use_exception_state(SafePointNode* phi_map) {
 446   if (failing()) { stop(); return top(); }
 447   Node* region = phi_map->control();
 448   Node* hidden_merge_mark = root();
 449   assert(phi_map->jvms()->map() == phi_map, "sanity: 1-1 relation");
 450   Node* ex_oop = clear_saved_ex_oop(phi_map);
 451   if (region->in(0) == hidden_merge_mark) {
 452     // Special marking for internal ex-states.  Process the phis now.
 453     region->set_req(0, region);  // now it's an ordinary region
 454     set_jvms(phi_map->jvms());   // ...so now we can use it as a map
 455     // Note: Setting the jvms also sets the bci and sp.
 456     set_control(_gvn.transform(region));
 457     uint tos = jvms()->stkoff() + sp();
 458     for (uint i = 1; i < tos; i++) {
 459       Node* x = phi_map->in(i);
 460       if (x->in(0) == region) {
 461         assert(x->is_Phi(), "expected a special phi");
 462         phi_map->set_req(i, _gvn.transform(x));
 463       }
 464     }
 465     for (MergeMemStream mms(merged_memory()); mms.next_non_empty(); ) {
 466       Node* x = mms.memory();
 467       if (x->in(0) == region) {
 468         assert(x->is_Phi(), "nobody else uses a hidden region");
 469         mms.set_memory(_gvn.transform(x));
 470       }
 471     }
 472     if (ex_oop->in(0) == region) {
 473       assert(ex_oop->is_Phi(), "expected a special phi");
 474       ex_oop = _gvn.transform(ex_oop);
 475     }
 476   } else {
 477     set_jvms(phi_map->jvms());
 478   }
 479 
 480   assert(!is_hidden_merge(phi_map->control()), "hidden ex. states cleared");
 481   assert(!is_hidden_merge(phi_map->i_o()), "hidden ex. states cleared");
 482   return ex_oop;
 483 }
 484 
 485 //---------------------------------java_bc-------------------------------------
 486 Bytecodes::Code GraphKit::java_bc() const {
 487   ciMethod* method = this->method();
 488   int       bci    = this->bci();
 489   if (method != NULL && bci != InvocationEntryBci)
 490     return method->java_code_at_bci(bci);
 491   else
 492     return Bytecodes::_illegal;
 493 }
 494 
 495 void GraphKit::uncommon_trap_if_should_post_on_exceptions(Deoptimization::DeoptReason reason,
 496                                                           bool must_throw) {
 497     // if the exception capability is set, then we will generate code
 498     // to check the JavaThread.should_post_on_exceptions flag to see
 499     // if we actually need to report exception events (for this
 500     // thread).  If we don't need to report exception events, we will
 501     // take the normal fast path provided by add_exception_events.  If
 502     // exception event reporting is enabled for this thread, we will
 503     // take the uncommon_trap in the BuildCutout below.
 504 
 505     // first must access the should_post_on_exceptions_flag in this thread's JavaThread
 506     Node* jthread = _gvn.transform(new ThreadLocalNode());
 507     Node* adr = basic_plus_adr(top(), jthread, in_bytes(JavaThread::should_post_on_exceptions_flag_offset()));
 508     Node* should_post_flag = make_load(control(), adr, TypeInt::INT, T_INT, Compile::AliasIdxRaw, MemNode::unordered);
 509 
 510     // Test the should_post_on_exceptions_flag vs. 0
 511     Node* chk = _gvn.transform( new CmpINode(should_post_flag, intcon(0)) );
 512     Node* tst = _gvn.transform( new BoolNode(chk, BoolTest::eq) );
 513 
 514     // Branch to slow_path if should_post_on_exceptions_flag was true
 515     { BuildCutout unless(this, tst, PROB_MAX);
 516       // Do not try anything fancy if we're notifying the VM on every throw.
 517       // Cf. case Bytecodes::_athrow in parse2.cpp.
 518       uncommon_trap(reason, Deoptimization::Action_none,
 519                     (ciKlass*)NULL, (char*)NULL, must_throw);
 520     }
 521 
 522 }
 523 
 524 //------------------------------builtin_throw----------------------------------
 525 void GraphKit::builtin_throw(Deoptimization::DeoptReason reason, Node* arg) {
 526   bool must_throw = true;
 527 
 528   if (env()->jvmti_can_post_on_exceptions()) {
 529     // check if we must post exception events, take uncommon trap if so
 530     uncommon_trap_if_should_post_on_exceptions(reason, must_throw);
 531     // here if should_post_on_exceptions is false
 532     // continue on with the normal codegen
 533   }
 534 
 535   // If this particular condition has not yet happened at this
 536   // bytecode, then use the uncommon trap mechanism, and allow for
 537   // a future recompilation if several traps occur here.
 538   // If the throw is hot, try to use a more complicated inline mechanism
 539   // which keeps execution inside the compiled code.
 540   bool treat_throw_as_hot = false;
 541   ciMethodData* md = method()->method_data();
 542 
 543   if (ProfileTraps) {
 544     if (too_many_traps(reason)) {
 545       treat_throw_as_hot = true;
 546     }
 547     // (If there is no MDO at all, assume it is early in
 548     // execution, and that any deopts are part of the
 549     // startup transient, and don't need to be remembered.)
 550 
 551     // Also, if there is a local exception handler, treat all throws
 552     // as hot if there has been at least one in this method.
 553     if (C->trap_count(reason) != 0
 554         && method()->method_data()->trap_count(reason) != 0
 555         && has_ex_handler()) {
 556         treat_throw_as_hot = true;
 557     }
 558   }
 559 
 560   // If this throw happens frequently, an uncommon trap might cause
 561   // a performance pothole.  If there is a local exception handler,
 562   // and if this particular bytecode appears to be deoptimizing often,
 563   // let us handle the throw inline, with a preconstructed instance.
 564   // Note:   If the deopt count has blown up, the uncommon trap
 565   // runtime is going to flush this nmethod, not matter what.
 566   if (treat_throw_as_hot
 567       && (!StackTraceInThrowable || OmitStackTraceInFastThrow)) {
 568     // If the throw is local, we use a pre-existing instance and
 569     // punt on the backtrace.  This would lead to a missing backtrace
 570     // (a repeat of 4292742) if the backtrace object is ever asked
 571     // for its backtrace.
 572     // Fixing this remaining case of 4292742 requires some flavor of
 573     // escape analysis.  Leave that for the future.
 574     ciInstance* ex_obj = NULL;
 575     switch (reason) {
 576     case Deoptimization::Reason_null_check:
 577       ex_obj = env()->NullPointerException_instance();
 578       break;
 579     case Deoptimization::Reason_div0_check:
 580       ex_obj = env()->ArithmeticException_instance();
 581       break;
 582     case Deoptimization::Reason_range_check:
 583       ex_obj = env()->ArrayIndexOutOfBoundsException_instance();
 584       break;
 585     case Deoptimization::Reason_class_check:
 586       if (java_bc() == Bytecodes::_aastore) {
 587         ex_obj = env()->ArrayStoreException_instance();
 588       } else {
 589         ex_obj = env()->ClassCastException_instance();
 590       }
 591       break;
 592     default:
 593       break;
 594     }
 595     if (failing()) { stop(); return; }  // exception allocation might fail
 596     if (ex_obj != NULL) {
 597       // Cheat with a preallocated exception object.
 598       if (C->log() != NULL)
 599         C->log()->elem("hot_throw preallocated='1' reason='%s'",
 600                        Deoptimization::trap_reason_name(reason));
 601       const TypeInstPtr* ex_con  = TypeInstPtr::make(ex_obj);
 602       Node*              ex_node = _gvn.transform(ConNode::make(ex_con));
 603 
 604       // Clear the detail message of the preallocated exception object.
 605       // Weblogic sometimes mutates the detail message of exceptions
 606       // using reflection.
 607       int offset = java_lang_Throwable::get_detailMessage_offset();
 608       const TypePtr* adr_typ = ex_con->add_offset(offset);
 609 
 610       Node *adr = basic_plus_adr(ex_node, ex_node, offset);
 611       const TypeOopPtr* val_type = TypeOopPtr::make_from_klass(env()->String_klass());
 612       Node *store = access_store_at(control(), ex_node, adr, adr_typ, null(), val_type, T_OBJECT, IN_HEAP);
 613 
 614       add_exception_state(make_exception_state(ex_node));
 615       return;
 616     }
 617   }
 618 
 619   // %%% Maybe add entry to OptoRuntime which directly throws the exc.?
 620   // It won't be much cheaper than bailing to the interp., since we'll
 621   // have to pass up all the debug-info, and the runtime will have to
 622   // create the stack trace.
 623 
 624   // Usual case:  Bail to interpreter.
 625   // Reserve the right to recompile if we haven't seen anything yet.
 626 
 627   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? C->method() : NULL;
 628   Deoptimization::DeoptAction action = Deoptimization::Action_maybe_recompile;
 629   if (treat_throw_as_hot
 630       && (method()->method_data()->trap_recompiled_at(bci(), m)
 631           || C->too_many_traps(reason))) {
 632     // We cannot afford to take more traps here.  Suffer in the interpreter.
 633     if (C->log() != NULL)
 634       C->log()->elem("hot_throw preallocated='0' reason='%s' mcount='%d'",
 635                      Deoptimization::trap_reason_name(reason),
 636                      C->trap_count(reason));
 637     action = Deoptimization::Action_none;
 638   }
 639 
 640   // "must_throw" prunes the JVM state to include only the stack, if there
 641   // are no local exception handlers.  This should cut down on register
 642   // allocation time and code size, by drastically reducing the number
 643   // of in-edges on the call to the uncommon trap.
 644 
 645   uncommon_trap(reason, action, (ciKlass*)NULL, (char*)NULL, must_throw);
 646 }
 647 
 648 
 649 //----------------------------PreserveJVMState---------------------------------
 650 PreserveJVMState::PreserveJVMState(GraphKit* kit, bool clone_map) {
 651   debug_only(kit->verify_map());
 652   _kit    = kit;
 653   _map    = kit->map();   // preserve the map
 654   _sp     = kit->sp();
 655   kit->set_map(clone_map ? kit->clone_map() : NULL);
 656 #ifdef ASSERT
 657   _bci    = kit->bci();
 658   Parse* parser = kit->is_Parse();
 659   int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo();
 660   _block  = block;
 661 #endif
 662 }
 663 PreserveJVMState::~PreserveJVMState() {
 664   GraphKit* kit = _kit;
 665 #ifdef ASSERT
 666   assert(kit->bci() == _bci, "bci must not shift");
 667   Parse* parser = kit->is_Parse();
 668   int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo();
 669   assert(block == _block,    "block must not shift");
 670 #endif
 671   kit->set_map(_map);
 672   kit->set_sp(_sp);
 673 }
 674 
 675 
 676 //-----------------------------BuildCutout-------------------------------------
 677 BuildCutout::BuildCutout(GraphKit* kit, Node* p, float prob, float cnt)
 678   : PreserveJVMState(kit)
 679 {
 680   assert(p->is_Con() || p->is_Bool(), "test must be a bool");
 681   SafePointNode* outer_map = _map;   // preserved map is caller's
 682   SafePointNode* inner_map = kit->map();
 683   IfNode* iff = kit->create_and_map_if(outer_map->control(), p, prob, cnt);
 684   outer_map->set_control(kit->gvn().transform( new IfTrueNode(iff) ));
 685   inner_map->set_control(kit->gvn().transform( new IfFalseNode(iff) ));
 686 }
 687 BuildCutout::~BuildCutout() {
 688   GraphKit* kit = _kit;
 689   assert(kit->stopped(), "cutout code must stop, throw, return, etc.");
 690 }
 691 
 692 //---------------------------PreserveReexecuteState----------------------------
 693 PreserveReexecuteState::PreserveReexecuteState(GraphKit* kit) {
 694   assert(!kit->stopped(), "must call stopped() before");
 695   _kit    =    kit;
 696   _sp     =    kit->sp();
 697   _reexecute = kit->jvms()->_reexecute;
 698 }
 699 PreserveReexecuteState::~PreserveReexecuteState() {
 700   if (_kit->stopped()) return;
 701   _kit->jvms()->_reexecute = _reexecute;
 702   _kit->set_sp(_sp);
 703 }
 704 
 705 //------------------------------clone_map--------------------------------------
 706 // Implementation of PreserveJVMState
 707 //
 708 // Only clone_map(...) here. If this function is only used in the
 709 // PreserveJVMState class we may want to get rid of this extra
 710 // function eventually and do it all there.
 711 
 712 SafePointNode* GraphKit::clone_map() {
 713   if (map() == NULL)  return NULL;
 714 
 715   // Clone the memory edge first
 716   Node* mem = MergeMemNode::make(map()->memory());
 717   gvn().set_type_bottom(mem);
 718 
 719   SafePointNode *clonemap = (SafePointNode*)map()->clone();
 720   JVMState* jvms = this->jvms();
 721   JVMState* clonejvms = jvms->clone_shallow(C);
 722   clonemap->set_memory(mem);
 723   clonemap->set_jvms(clonejvms);
 724   clonejvms->set_map(clonemap);
 725   record_for_igvn(clonemap);
 726   gvn().set_type_bottom(clonemap);
 727   return clonemap;
 728 }
 729 
 730 
 731 //-----------------------------set_map_clone-----------------------------------
 732 void GraphKit::set_map_clone(SafePointNode* m) {
 733   _map = m;
 734   _map = clone_map();
 735   _map->set_next_exception(NULL);
 736   debug_only(verify_map());
 737 }
 738 
 739 
 740 //----------------------------kill_dead_locals---------------------------------
 741 // Detect any locals which are known to be dead, and force them to top.
 742 void GraphKit::kill_dead_locals() {
 743   // Consult the liveness information for the locals.  If any
 744   // of them are unused, then they can be replaced by top().  This
 745   // should help register allocation time and cut down on the size
 746   // of the deoptimization information.
 747 
 748   // This call is made from many of the bytecode handling
 749   // subroutines called from the Big Switch in do_one_bytecode.
 750   // Every bytecode which might include a slow path is responsible
 751   // for killing its dead locals.  The more consistent we
 752   // are about killing deads, the fewer useless phis will be
 753   // constructed for them at various merge points.
 754 
 755   // bci can be -1 (InvocationEntryBci).  We return the entry
 756   // liveness for the method.
 757 
 758   if (method() == NULL || method()->code_size() == 0) {
 759     // We are building a graph for a call to a native method.
 760     // All locals are live.
 761     return;
 762   }
 763 
 764   ResourceMark rm;
 765 
 766   // Consult the liveness information for the locals.  If any
 767   // of them are unused, then they can be replaced by top().  This
 768   // should help register allocation time and cut down on the size
 769   // of the deoptimization information.
 770   MethodLivenessResult live_locals = method()->liveness_at_bci(bci());
 771 
 772   int len = (int)live_locals.size();
 773   assert(len <= jvms()->loc_size(), "too many live locals");
 774   for (int local = 0; local < len; local++) {
 775     if (!live_locals.at(local)) {
 776       set_local(local, top());
 777     }
 778   }
 779 }
 780 
 781 #ifdef ASSERT
 782 //-------------------------dead_locals_are_killed------------------------------
 783 // Return true if all dead locals are set to top in the map.
 784 // Used to assert "clean" debug info at various points.
 785 bool GraphKit::dead_locals_are_killed() {
 786   if (method() == NULL || method()->code_size() == 0) {
 787     // No locals need to be dead, so all is as it should be.
 788     return true;
 789   }
 790 
 791   // Make sure somebody called kill_dead_locals upstream.
 792   ResourceMark rm;
 793   for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) {
 794     if (jvms->loc_size() == 0)  continue;  // no locals to consult
 795     SafePointNode* map = jvms->map();
 796     ciMethod* method = jvms->method();
 797     int       bci    = jvms->bci();
 798     if (jvms == this->jvms()) {
 799       bci = this->bci();  // it might not yet be synched
 800     }
 801     MethodLivenessResult live_locals = method->liveness_at_bci(bci);
 802     int len = (int)live_locals.size();
 803     if (!live_locals.is_valid() || len == 0)
 804       // This method is trivial, or is poisoned by a breakpoint.
 805       return true;
 806     assert(len == jvms->loc_size(), "live map consistent with locals map");
 807     for (int local = 0; local < len; local++) {
 808       if (!live_locals.at(local) && map->local(jvms, local) != top()) {
 809         if (PrintMiscellaneous && (Verbose || WizardMode)) {
 810           tty->print_cr("Zombie local %d: ", local);
 811           jvms->dump();
 812         }
 813         return false;
 814       }
 815     }
 816   }
 817   return true;
 818 }
 819 
 820 #endif //ASSERT
 821 
 822 // Helper function for enforcing certain bytecodes to reexecute if deoptimization happens.
 823 static bool should_reexecute_implied_by_bytecode(JVMState *jvms, bool is_anewarray) {
 824   ciMethod* cur_method = jvms->method();
 825   int       cur_bci   = jvms->bci();
 826   if (cur_method != NULL && cur_bci != InvocationEntryBci) {
 827     Bytecodes::Code code = cur_method->java_code_at_bci(cur_bci);
 828     return Interpreter::bytecode_should_reexecute(code) ||
 829            (is_anewarray && code == Bytecodes::_multianewarray);
 830     // Reexecute _multianewarray bytecode which was replaced with
 831     // sequence of [a]newarray. See Parse::do_multianewarray().
 832     //
 833     // Note: interpreter should not have it set since this optimization
 834     // is limited by dimensions and guarded by flag so in some cases
 835     // multianewarray() runtime calls will be generated and
 836     // the bytecode should not be reexecutes (stack will not be reset).
 837   } else {
 838     return false;
 839   }
 840 }
 841 
 842 // Helper function for adding JVMState and debug information to node
 843 void GraphKit::add_safepoint_edges(SafePointNode* call, bool must_throw) {
 844   // Add the safepoint edges to the call (or other safepoint).
 845 
 846   // Make sure dead locals are set to top.  This
 847   // should help register allocation time and cut down on the size
 848   // of the deoptimization information.
 849   assert(dead_locals_are_killed(), "garbage in debug info before safepoint");
 850 
 851   // Walk the inline list to fill in the correct set of JVMState's
 852   // Also fill in the associated edges for each JVMState.
 853 
 854   // If the bytecode needs to be reexecuted we need to put
 855   // the arguments back on the stack.
 856   const bool should_reexecute = jvms()->should_reexecute();
 857   JVMState* youngest_jvms = should_reexecute ? sync_jvms_for_reexecute() : sync_jvms();
 858 
 859   // NOTE: set_bci (called from sync_jvms) might reset the reexecute bit to
 860   // undefined if the bci is different.  This is normal for Parse but it
 861   // should not happen for LibraryCallKit because only one bci is processed.
 862   assert(!is_LibraryCallKit() || (jvms()->should_reexecute() == should_reexecute),
 863          "in LibraryCallKit the reexecute bit should not change");
 864 
 865   // If we are guaranteed to throw, we can prune everything but the
 866   // input to the current bytecode.
 867   bool can_prune_locals = false;
 868   uint stack_slots_not_pruned = 0;
 869   int inputs = 0, depth = 0;
 870   if (must_throw) {
 871     assert(method() == youngest_jvms->method(), "sanity");
 872     if (compute_stack_effects(inputs, depth)) {
 873       can_prune_locals = true;
 874       stack_slots_not_pruned = inputs;
 875     }
 876   }
 877 
 878   if (env()->should_retain_local_variables()) {
 879     // At any safepoint, this method can get breakpointed, which would
 880     // then require an immediate deoptimization.
 881     can_prune_locals = false;  // do not prune locals
 882     stack_slots_not_pruned = 0;
 883   }
 884 
 885   // do not scribble on the input jvms
 886   JVMState* out_jvms = youngest_jvms->clone_deep(C);
 887   call->set_jvms(out_jvms); // Start jvms list for call node
 888 
 889   // For a known set of bytecodes, the interpreter should reexecute them if
 890   // deoptimization happens. We set the reexecute state for them here
 891   if (out_jvms->is_reexecute_undefined() && //don't change if already specified
 892       should_reexecute_implied_by_bytecode(out_jvms, call->is_AllocateArray())) {
 893 #ifdef ASSERT
 894     int inputs = 0, not_used; // initialized by GraphKit::compute_stack_effects()
 895     assert(method() == youngest_jvms->method(), "sanity");
 896     assert(compute_stack_effects(inputs, not_used), "unknown bytecode: %s", Bytecodes::name(java_bc()));
 897     assert(out_jvms->sp() >= (uint)inputs, "not enough operands for reexecution");
 898 #endif // ASSERT
 899     out_jvms->set_should_reexecute(true); //NOTE: youngest_jvms not changed
 900   }
 901 
 902   // Presize the call:
 903   DEBUG_ONLY(uint non_debug_edges = call->req());
 904   call->add_req_batch(top(), youngest_jvms->debug_depth());
 905   assert(call->req() == non_debug_edges + youngest_jvms->debug_depth(), "");
 906 
 907   // Set up edges so that the call looks like this:
 908   //  Call [state:] ctl io mem fptr retadr
 909   //       [parms:] parm0 ... parmN
 910   //       [root:]  loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN
 911   //    [...mid:]   loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN [...]
 912   //       [young:] loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN
 913   // Note that caller debug info precedes callee debug info.
 914 
 915   // Fill pointer walks backwards from "young:" to "root:" in the diagram above:
 916   uint debug_ptr = call->req();
 917 
 918   // Loop over the map input edges associated with jvms, add them
 919   // to the call node, & reset all offsets to match call node array.
 920   for (JVMState* in_jvms = youngest_jvms; in_jvms != NULL; ) {
 921     uint debug_end   = debug_ptr;
 922     uint debug_start = debug_ptr - in_jvms->debug_size();
 923     debug_ptr = debug_start;  // back up the ptr
 924 
 925     uint p = debug_start;  // walks forward in [debug_start, debug_end)
 926     uint j, k, l;
 927     SafePointNode* in_map = in_jvms->map();
 928     out_jvms->set_map(call);
 929 
 930     if (can_prune_locals) {
 931       assert(in_jvms->method() == out_jvms->method(), "sanity");
 932       // If the current throw can reach an exception handler in this JVMS,
 933       // then we must keep everything live that can reach that handler.
 934       // As a quick and dirty approximation, we look for any handlers at all.
 935       if (in_jvms->method()->has_exception_handlers()) {
 936         can_prune_locals = false;
 937       }
 938     }
 939 
 940     // Add the Locals
 941     k = in_jvms->locoff();
 942     l = in_jvms->loc_size();
 943     out_jvms->set_locoff(p);
 944     if (!can_prune_locals) {
 945       for (j = 0; j < l; j++)
 946         call->set_req(p++, in_map->in(k+j));
 947     } else {
 948       p += l;  // already set to top above by add_req_batch
 949     }
 950 
 951     // Add the Expression Stack
 952     k = in_jvms->stkoff();
 953     l = in_jvms->sp();
 954     out_jvms->set_stkoff(p);
 955     if (!can_prune_locals) {
 956       for (j = 0; j < l; j++)
 957         call->set_req(p++, in_map->in(k+j));
 958     } else if (can_prune_locals && stack_slots_not_pruned != 0) {
 959       // Divide stack into {S0,...,S1}, where S0 is set to top.
 960       uint s1 = stack_slots_not_pruned;
 961       stack_slots_not_pruned = 0;  // for next iteration
 962       if (s1 > l)  s1 = l;
 963       uint s0 = l - s1;
 964       p += s0;  // skip the tops preinstalled by add_req_batch
 965       for (j = s0; j < l; j++)
 966         call->set_req(p++, in_map->in(k+j));
 967     } else {
 968       p += l;  // already set to top above by add_req_batch
 969     }
 970 
 971     // Add the Monitors
 972     k = in_jvms->monoff();
 973     l = in_jvms->mon_size();
 974     out_jvms->set_monoff(p);
 975     for (j = 0; j < l; j++)
 976       call->set_req(p++, in_map->in(k+j));
 977 
 978     // Copy any scalar object fields.
 979     k = in_jvms->scloff();
 980     l = in_jvms->scl_size();
 981     out_jvms->set_scloff(p);
 982     for (j = 0; j < l; j++)
 983       call->set_req(p++, in_map->in(k+j));
 984 
 985     // Finish the new jvms.
 986     out_jvms->set_endoff(p);
 987 
 988     assert(out_jvms->endoff()     == debug_end,             "fill ptr must match");
 989     assert(out_jvms->depth()      == in_jvms->depth(),      "depth must match");
 990     assert(out_jvms->loc_size()   == in_jvms->loc_size(),   "size must match");
 991     assert(out_jvms->mon_size()   == in_jvms->mon_size(),   "size must match");
 992     assert(out_jvms->scl_size()   == in_jvms->scl_size(),   "size must match");
 993     assert(out_jvms->debug_size() == in_jvms->debug_size(), "size must match");
 994 
 995     // Update the two tail pointers in parallel.
 996     out_jvms = out_jvms->caller();
 997     in_jvms  = in_jvms->caller();
 998   }
 999 
1000   assert(debug_ptr == non_debug_edges, "debug info must fit exactly");
1001 
1002   // Test the correctness of JVMState::debug_xxx accessors:
1003   assert(call->jvms()->debug_start() == non_debug_edges, "");
1004   assert(call->jvms()->debug_end()   == call->req(), "");
1005   assert(call->jvms()->debug_depth() == call->req() - non_debug_edges, "");
1006 }
1007 
1008 bool GraphKit::compute_stack_effects(int& inputs, int& depth) {
1009   Bytecodes::Code code = java_bc();
1010   if (code == Bytecodes::_wide) {
1011     code = method()->java_code_at_bci(bci() + 1);
1012   }
1013 
1014   BasicType rtype = T_ILLEGAL;
1015   int       rsize = 0;
1016 
1017   if (code != Bytecodes::_illegal) {
1018     depth = Bytecodes::depth(code); // checkcast=0, athrow=-1
1019     rtype = Bytecodes::result_type(code); // checkcast=P, athrow=V
1020     if (rtype < T_CONFLICT)
1021       rsize = type2size[rtype];
1022   }
1023 
1024   switch (code) {
1025   case Bytecodes::_illegal:
1026     return false;
1027 
1028   case Bytecodes::_ldc:
1029   case Bytecodes::_ldc_w:
1030   case Bytecodes::_ldc2_w:
1031     inputs = 0;
1032     break;
1033 
1034   case Bytecodes::_dup:         inputs = 1;  break;
1035   case Bytecodes::_dup_x1:      inputs = 2;  break;
1036   case Bytecodes::_dup_x2:      inputs = 3;  break;
1037   case Bytecodes::_dup2:        inputs = 2;  break;
1038   case Bytecodes::_dup2_x1:     inputs = 3;  break;
1039   case Bytecodes::_dup2_x2:     inputs = 4;  break;
1040   case Bytecodes::_swap:        inputs = 2;  break;
1041   case Bytecodes::_arraylength: inputs = 1;  break;
1042 
1043   case Bytecodes::_getstatic:
1044   case Bytecodes::_putstatic:
1045   case Bytecodes::_getfield:
1046   case Bytecodes::_putfield:
1047     {
1048       bool ignored_will_link;
1049       ciField* field = method()->get_field_at_bci(bci(), ignored_will_link);
1050       int      size  = field->type()->size();
1051       bool is_get = (depth >= 0), is_static = (depth & 1);
1052       inputs = (is_static ? 0 : 1);
1053       if (is_get) {
1054         depth = size - inputs;
1055       } else {
1056         inputs += size;        // putxxx pops the value from the stack
1057         depth = - inputs;
1058       }
1059     }
1060     break;
1061 
1062   case Bytecodes::_invokevirtual:
1063   case Bytecodes::_invokespecial:
1064   case Bytecodes::_invokestatic:
1065   case Bytecodes::_invokedynamic:
1066   case Bytecodes::_invokeinterface:
1067     {
1068       bool ignored_will_link;
1069       ciSignature* declared_signature = NULL;
1070       ciMethod* ignored_callee = method()->get_method_at_bci(bci(), ignored_will_link, &declared_signature);
1071       assert(declared_signature != NULL, "cannot be null");
1072       inputs   = declared_signature->arg_size_for_bc(code);
1073       int size = declared_signature->return_type()->size();
1074       depth = size - inputs;
1075     }
1076     break;
1077 
1078   case Bytecodes::_multianewarray:
1079     {
1080       ciBytecodeStream iter(method());
1081       iter.reset_to_bci(bci());
1082       iter.next();
1083       inputs = iter.get_dimensions();
1084       assert(rsize == 1, "");
1085       depth = rsize - inputs;
1086     }
1087     break;
1088 
1089   case Bytecodes::_ireturn:
1090   case Bytecodes::_lreturn:
1091   case Bytecodes::_freturn:
1092   case Bytecodes::_dreturn:
1093   case Bytecodes::_areturn:
1094     assert(rsize == -depth, "");
1095     inputs = rsize;
1096     break;
1097 
1098   case Bytecodes::_jsr:
1099   case Bytecodes::_jsr_w:
1100     inputs = 0;
1101     depth  = 1;                  // S.B. depth=1, not zero
1102     break;
1103 
1104   default:
1105     // bytecode produces a typed result
1106     inputs = rsize - depth;
1107     assert(inputs >= 0, "");
1108     break;
1109   }
1110 
1111 #ifdef ASSERT
1112   // spot check
1113   int outputs = depth + inputs;
1114   assert(outputs >= 0, "sanity");
1115   switch (code) {
1116   case Bytecodes::_checkcast: assert(inputs == 1 && outputs == 1, ""); break;
1117   case Bytecodes::_athrow:    assert(inputs == 1 && outputs == 0, ""); break;
1118   case Bytecodes::_aload_0:   assert(inputs == 0 && outputs == 1, ""); break;
1119   case Bytecodes::_return:    assert(inputs == 0 && outputs == 0, ""); break;
1120   case Bytecodes::_drem:      assert(inputs == 4 && outputs == 2, ""); break;
1121   default:                    break;
1122   }
1123 #endif //ASSERT
1124 
1125   return true;
1126 }
1127 
1128 
1129 
1130 //------------------------------basic_plus_adr---------------------------------
1131 Node* GraphKit::basic_plus_adr(Node* base, Node* ptr, Node* offset) {
1132   // short-circuit a common case
1133   if (offset == intcon(0))  return ptr;
1134   return _gvn.transform( new AddPNode(base, ptr, offset) );
1135 }
1136 
1137 Node* GraphKit::ConvI2L(Node* offset) {
1138   // short-circuit a common case
1139   jint offset_con = find_int_con(offset, Type::OffsetBot);
1140   if (offset_con != Type::OffsetBot) {
1141     return longcon((jlong) offset_con);
1142   }
1143   return _gvn.transform( new ConvI2LNode(offset));
1144 }
1145 
1146 Node* GraphKit::ConvI2UL(Node* offset) {
1147   juint offset_con = (juint) find_int_con(offset, Type::OffsetBot);
1148   if (offset_con != (juint) Type::OffsetBot) {
1149     return longcon((julong) offset_con);
1150   }
1151   Node* conv = _gvn.transform( new ConvI2LNode(offset));
1152   Node* mask = _gvn.transform(ConLNode::make((julong) max_juint));
1153   return _gvn.transform( new AndLNode(conv, mask) );
1154 }
1155 
1156 Node* GraphKit::ConvL2I(Node* offset) {
1157   // short-circuit a common case
1158   jlong offset_con = find_long_con(offset, (jlong)Type::OffsetBot);
1159   if (offset_con != (jlong)Type::OffsetBot) {
1160     return intcon((int) offset_con);
1161   }
1162   return _gvn.transform( new ConvL2INode(offset));
1163 }
1164 
1165 //-------------------------load_object_klass-----------------------------------
1166 Node* GraphKit::load_object_klass(Node* obj) {
1167   // Special-case a fresh allocation to avoid building nodes:
1168   Node* akls = AllocateNode::Ideal_klass(obj, &_gvn);
1169   if (akls != NULL)  return akls;
1170   Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes());
1171   return _gvn.transform(LoadKlassNode::make(_gvn, NULL, immutable_memory(), k_adr, TypeInstPtr::KLASS));
1172 }
1173 
1174 //-------------------------load_array_length-----------------------------------
1175 Node* GraphKit::load_array_length(Node* array) {
1176   // Special-case a fresh allocation to avoid building nodes:
1177   AllocateArrayNode* alloc = AllocateArrayNode::Ideal_array_allocation(array, &_gvn);
1178   Node *alen;
1179   if (alloc == NULL) {
1180     Node *r_adr = basic_plus_adr(array, arrayOopDesc::length_offset_in_bytes());
1181     alen = _gvn.transform( new LoadRangeNode(0, immutable_memory(), r_adr, TypeInt::POS));
1182   } else {
1183     alen = alloc->Ideal_length();
1184     Node* ccast = alloc->make_ideal_length(_gvn.type(array)->is_oopptr(), &_gvn);
1185     if (ccast != alen) {
1186       alen = _gvn.transform(ccast);
1187     }
1188   }
1189   return alen;
1190 }
1191 
1192 //------------------------------do_null_check----------------------------------
1193 // Helper function to do a NULL pointer check.  Returned value is
1194 // the incoming address with NULL casted away.  You are allowed to use the
1195 // not-null value only if you are control dependent on the test.
1196 #ifndef PRODUCT
1197 extern int explicit_null_checks_inserted,
1198            explicit_null_checks_elided;
1199 #endif
1200 Node* GraphKit::null_check_common(Node* value, BasicType type,
1201                                   // optional arguments for variations:
1202                                   bool assert_null,
1203                                   Node* *null_control,
1204                                   bool speculative) {
1205   assert(!assert_null || null_control == NULL, "not both at once");
1206   if (stopped())  return top();
1207   NOT_PRODUCT(explicit_null_checks_inserted++);
1208 
1209   // Construct NULL check
1210   Node *chk = NULL;
1211   switch(type) {
1212     case T_LONG   : chk = new CmpLNode(value, _gvn.zerocon(T_LONG)); break;
1213     case T_INT    : chk = new CmpINode(value, _gvn.intcon(0)); break;
1214     case T_ARRAY  : // fall through
1215       type = T_OBJECT;  // simplify further tests
1216     case T_OBJECT : {
1217       const Type *t = _gvn.type( value );
1218 
1219       const TypeOopPtr* tp = t->isa_oopptr();
1220       if (tp != NULL && tp->klass() != NULL && !tp->klass()->is_loaded()
1221           // Only for do_null_check, not any of its siblings:
1222           && !assert_null && null_control == NULL) {
1223         // Usually, any field access or invocation on an unloaded oop type
1224         // will simply fail to link, since the statically linked class is
1225         // likely also to be unloaded.  However, in -Xcomp mode, sometimes
1226         // the static class is loaded but the sharper oop type is not.
1227         // Rather than checking for this obscure case in lots of places,
1228         // we simply observe that a null check on an unloaded class
1229         // will always be followed by a nonsense operation, so we
1230         // can just issue the uncommon trap here.
1231         // Our access to the unloaded class will only be correct
1232         // after it has been loaded and initialized, which requires
1233         // a trip through the interpreter.
1234 #ifndef PRODUCT
1235         if (WizardMode) { tty->print("Null check of unloaded "); tp->klass()->print(); tty->cr(); }
1236 #endif
1237         uncommon_trap(Deoptimization::Reason_unloaded,
1238                       Deoptimization::Action_reinterpret,
1239                       tp->klass(), "!loaded");
1240         return top();
1241       }
1242 
1243       if (assert_null) {
1244         // See if the type is contained in NULL_PTR.
1245         // If so, then the value is already null.
1246         if (t->higher_equal(TypePtr::NULL_PTR)) {
1247           NOT_PRODUCT(explicit_null_checks_elided++);
1248           return value;           // Elided null assert quickly!
1249         }
1250       } else {
1251         // See if mixing in the NULL pointer changes type.
1252         // If so, then the NULL pointer was not allowed in the original
1253         // type.  In other words, "value" was not-null.
1254         if (t->meet(TypePtr::NULL_PTR) != t->remove_speculative()) {
1255           // same as: if (!TypePtr::NULL_PTR->higher_equal(t)) ...
1256           NOT_PRODUCT(explicit_null_checks_elided++);
1257           return value;           // Elided null check quickly!
1258         }
1259       }
1260       chk = new CmpPNode( value, null() );
1261       break;
1262     }
1263 
1264     default:
1265       fatal("unexpected type: %s", type2name(type));
1266   }
1267   assert(chk != NULL, "sanity check");
1268   chk = _gvn.transform(chk);
1269 
1270   BoolTest::mask btest = assert_null ? BoolTest::eq : BoolTest::ne;
1271   BoolNode *btst = new BoolNode( chk, btest);
1272   Node   *tst = _gvn.transform( btst );
1273 
1274   //-----------
1275   // if peephole optimizations occurred, a prior test existed.
1276   // If a prior test existed, maybe it dominates as we can avoid this test.
1277   if (tst != btst && type == T_OBJECT) {
1278     // At this point we want to scan up the CFG to see if we can
1279     // find an identical test (and so avoid this test altogether).
1280     Node *cfg = control();
1281     int depth = 0;
1282     while( depth < 16 ) {       // Limit search depth for speed
1283       if( cfg->Opcode() == Op_IfTrue &&
1284           cfg->in(0)->in(1) == tst ) {
1285         // Found prior test.  Use "cast_not_null" to construct an identical
1286         // CastPP (and hence hash to) as already exists for the prior test.
1287         // Return that casted value.
1288         if (assert_null) {
1289           replace_in_map(value, null());
1290           return null();  // do not issue the redundant test
1291         }
1292         Node *oldcontrol = control();
1293         set_control(cfg);
1294         Node *res = cast_not_null(value);
1295         set_control(oldcontrol);
1296         NOT_PRODUCT(explicit_null_checks_elided++);
1297         return res;
1298       }
1299       cfg = IfNode::up_one_dom(cfg, /*linear_only=*/ true);
1300       if (cfg == NULL)  break;  // Quit at region nodes
1301       depth++;
1302     }
1303   }
1304 
1305   //-----------
1306   // Branch to failure if null
1307   float ok_prob = PROB_MAX;  // a priori estimate:  nulls never happen
1308   Deoptimization::DeoptReason reason;
1309   if (assert_null) {
1310     reason = Deoptimization::reason_null_assert(speculative);
1311   } else if (type == T_OBJECT) {
1312     reason = Deoptimization::reason_null_check(speculative);
1313   } else {
1314     reason = Deoptimization::Reason_div0_check;
1315   }
1316   // %%% Since Reason_unhandled is not recorded on a per-bytecode basis,
1317   // ciMethodData::has_trap_at will return a conservative -1 if any
1318   // must-be-null assertion has failed.  This could cause performance
1319   // problems for a method after its first do_null_assert failure.
1320   // Consider using 'Reason_class_check' instead?
1321 
1322   // To cause an implicit null check, we set the not-null probability
1323   // to the maximum (PROB_MAX).  For an explicit check the probability
1324   // is set to a smaller value.
1325   if (null_control != NULL || too_many_traps(reason)) {
1326     // probability is less likely
1327     ok_prob =  PROB_LIKELY_MAG(3);
1328   } else if (!assert_null &&
1329              (ImplicitNullCheckThreshold > 0) &&
1330              method() != NULL &&
1331              (method()->method_data()->trap_count(reason)
1332               >= (uint)ImplicitNullCheckThreshold)) {
1333     ok_prob =  PROB_LIKELY_MAG(3);
1334   }
1335 
1336   if (null_control != NULL) {
1337     IfNode* iff = create_and_map_if(control(), tst, ok_prob, COUNT_UNKNOWN);
1338     Node* null_true = _gvn.transform( new IfFalseNode(iff));
1339     set_control(      _gvn.transform( new IfTrueNode(iff)));
1340 #ifndef PRODUCT
1341     if (null_true == top()) {
1342       explicit_null_checks_elided++;
1343     }
1344 #endif
1345     (*null_control) = null_true;
1346   } else {
1347     BuildCutout unless(this, tst, ok_prob);
1348     // Check for optimizer eliding test at parse time
1349     if (stopped()) {
1350       // Failure not possible; do not bother making uncommon trap.
1351       NOT_PRODUCT(explicit_null_checks_elided++);
1352     } else if (assert_null) {
1353       uncommon_trap(reason,
1354                     Deoptimization::Action_make_not_entrant,
1355                     NULL, "assert_null");
1356     } else {
1357       replace_in_map(value, zerocon(type));
1358       builtin_throw(reason);
1359     }
1360   }
1361 
1362   // Must throw exception, fall-thru not possible?
1363   if (stopped()) {
1364     return top();               // No result
1365   }
1366 
1367   if (assert_null) {
1368     // Cast obj to null on this path.
1369     replace_in_map(value, zerocon(type));
1370     return zerocon(type);
1371   }
1372 
1373   // Cast obj to not-null on this path, if there is no null_control.
1374   // (If there is a null_control, a non-null value may come back to haunt us.)
1375   if (type == T_OBJECT) {
1376     Node* cast = cast_not_null(value, false);
1377     if (null_control == NULL || (*null_control) == top())
1378       replace_in_map(value, cast);
1379     value = cast;
1380   }
1381 
1382   return value;
1383 }
1384 
1385 
1386 //------------------------------cast_not_null----------------------------------
1387 // Cast obj to not-null on this path
1388 Node* GraphKit::cast_not_null(Node* obj, bool do_replace_in_map) {
1389   const Type *t = _gvn.type(obj);
1390   const Type *t_not_null = t->join_speculative(TypePtr::NOTNULL);
1391   // Object is already not-null?
1392   if( t == t_not_null ) return obj;
1393 
1394   Node *cast = new CastPPNode(obj,t_not_null);
1395   cast->init_req(0, control());
1396   cast = _gvn.transform( cast );
1397 
1398   // Scan for instances of 'obj' in the current JVM mapping.
1399   // These instances are known to be not-null after the test.
1400   if (do_replace_in_map)
1401     replace_in_map(obj, cast);
1402 
1403   return cast;                  // Return casted value
1404 }
1405 
1406 // Sometimes in intrinsics, we implicitly know an object is not null
1407 // (there's no actual null check) so we can cast it to not null. In
1408 // the course of optimizations, the input to the cast can become null.
1409 // In that case that data path will die and we need the control path
1410 // to become dead as well to keep the graph consistent. So we have to
1411 // add a check for null for which one branch can't be taken. It uses
1412 // an Opaque4 node that will cause the check to be removed after loop
1413 // opts so the test goes away and the compiled code doesn't execute a
1414 // useless check.
1415 Node* GraphKit::must_be_not_null(Node* value, bool do_replace_in_map) {
1416   if (!TypePtr::NULL_PTR->higher_equal(_gvn.type(value))) {
1417     return value;
1418   }
1419   Node* chk = _gvn.transform(new CmpPNode(value, null()));
1420   Node *tst = _gvn.transform(new BoolNode(chk, BoolTest::ne));
1421   Node* opaq = _gvn.transform(new Opaque4Node(C, tst, intcon(1)));
1422   IfNode *iff = new IfNode(control(), opaq, PROB_MAX, COUNT_UNKNOWN);
1423   _gvn.set_type(iff, iff->Value(&_gvn));
1424   Node *if_f = _gvn.transform(new IfFalseNode(iff));
1425   Node *frame = _gvn.transform(new ParmNode(C->start(), TypeFunc::FramePtr));
1426   Node* halt = _gvn.transform(new HaltNode(if_f, frame, "unexpected null in intrinsic"));
1427   C->root()->add_req(halt);
1428   Node *if_t = _gvn.transform(new IfTrueNode(iff));
1429   set_control(if_t);
1430   return cast_not_null(value, do_replace_in_map);
1431 }
1432 
1433 
1434 //--------------------------replace_in_map-------------------------------------
1435 void GraphKit::replace_in_map(Node* old, Node* neww) {
1436   if (old == neww) {
1437     return;
1438   }
1439 
1440   map()->replace_edge(old, neww);
1441 
1442   // Note: This operation potentially replaces any edge
1443   // on the map.  This includes locals, stack, and monitors
1444   // of the current (innermost) JVM state.
1445 
1446   // don't let inconsistent types from profiling escape this
1447   // method
1448 
1449   const Type* told = _gvn.type(old);
1450   const Type* tnew = _gvn.type(neww);
1451 
1452   if (!tnew->higher_equal(told)) {
1453     return;
1454   }
1455 
1456   map()->record_replaced_node(old, neww);
1457 }
1458 
1459 
1460 //=============================================================================
1461 //--------------------------------memory---------------------------------------
1462 Node* GraphKit::memory(uint alias_idx) {
1463   MergeMemNode* mem = merged_memory();
1464   Node* p = mem->memory_at(alias_idx);
1465   _gvn.set_type(p, Type::MEMORY);  // must be mapped
1466   return p;
1467 }
1468 
1469 //-----------------------------reset_memory------------------------------------
1470 Node* GraphKit::reset_memory() {
1471   Node* mem = map()->memory();
1472   // do not use this node for any more parsing!
1473   debug_only( map()->set_memory((Node*)NULL) );
1474   return _gvn.transform( mem );
1475 }
1476 
1477 //------------------------------set_all_memory---------------------------------
1478 void GraphKit::set_all_memory(Node* newmem) {
1479   Node* mergemem = MergeMemNode::make(newmem);
1480   gvn().set_type_bottom(mergemem);
1481   map()->set_memory(mergemem);
1482 }
1483 
1484 //------------------------------set_all_memory_call----------------------------
1485 void GraphKit::set_all_memory_call(Node* call, bool separate_io_proj) {
1486   Node* newmem = _gvn.transform( new ProjNode(call, TypeFunc::Memory, separate_io_proj) );
1487   set_all_memory(newmem);
1488 }
1489 
1490 //=============================================================================
1491 //
1492 // parser factory methods for MemNodes
1493 //
1494 // These are layered on top of the factory methods in LoadNode and StoreNode,
1495 // and integrate with the parser's memory state and _gvn engine.
1496 //
1497 
1498 // factory methods in "int adr_idx"
1499 Node* GraphKit::make_load(Node* ctl, Node* adr, const Type* t, BasicType bt,
1500                           int adr_idx,
1501                           MemNode::MemOrd mo,
1502                           LoadNode::ControlDependency control_dependency,
1503                           bool require_atomic_access,
1504                           bool unaligned,
1505                           bool mismatched,
1506                           bool unsafe) {
1507   assert(adr_idx != Compile::AliasIdxTop, "use other make_load factory" );
1508   const TypePtr* adr_type = NULL; // debug-mode-only argument
1509   debug_only(adr_type = C->get_adr_type(adr_idx));
1510   Node* mem = memory(adr_idx);
1511   Node* ld;
1512   if (require_atomic_access && bt == T_LONG) {
1513     ld = LoadLNode::make_atomic(ctl, mem, adr, adr_type, t, mo, control_dependency, unaligned, mismatched, unsafe);
1514   } else if (require_atomic_access && bt == T_DOUBLE) {
1515     ld = LoadDNode::make_atomic(ctl, mem, adr, adr_type, t, mo, control_dependency, unaligned, mismatched, unsafe);
1516   } else {
1517     ld = LoadNode::make(_gvn, ctl, mem, adr, adr_type, t, bt, mo, control_dependency, unaligned, mismatched, unsafe);
1518   }
1519   ld = _gvn.transform(ld);
1520   if (((bt == T_OBJECT) && C->do_escape_analysis()) || C->eliminate_boxing()) {
1521     // Improve graph before escape analysis and boxing elimination.
1522     record_for_igvn(ld);
1523   }
1524   return ld;
1525 }
1526 
1527 Node* GraphKit::store_to_memory(Node* ctl, Node* adr, Node *val, BasicType bt,
1528                                 int adr_idx,
1529                                 MemNode::MemOrd mo,
1530                                 bool require_atomic_access,
1531                                 bool unaligned,
1532                                 bool mismatched,
1533                                 bool unsafe) {
1534   assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
1535   const TypePtr* adr_type = NULL;
1536   debug_only(adr_type = C->get_adr_type(adr_idx));
1537   Node *mem = memory(adr_idx);
1538   Node* st;
1539   if (require_atomic_access && bt == T_LONG) {
1540     st = StoreLNode::make_atomic(ctl, mem, adr, adr_type, val, mo);
1541   } else if (require_atomic_access && bt == T_DOUBLE) {
1542     st = StoreDNode::make_atomic(ctl, mem, adr, adr_type, val, mo);
1543   } else {
1544     st = StoreNode::make(_gvn, ctl, mem, adr, adr_type, val, bt, mo);
1545   }
1546   if (unaligned) {
1547     st->as_Store()->set_unaligned_access();
1548   }
1549   if (mismatched) {
1550     st->as_Store()->set_mismatched_access();
1551   }
1552   if (unsafe) {
1553     st->as_Store()->set_unsafe_access();
1554   }
1555   st = _gvn.transform(st);
1556   set_memory(st, adr_idx);
1557   // Back-to-back stores can only remove intermediate store with DU info
1558   // so push on worklist for optimizer.
1559   if (mem->req() > MemNode::Address && adr == mem->in(MemNode::Address))
1560     record_for_igvn(st);
1561 
1562   return st;
1563 }
1564 
1565 Node* GraphKit::access_store_at(Node* ctl,
1566                                 Node* obj,
1567                                 Node* adr,
1568                                 const TypePtr* adr_type,
1569                                 Node* val,
1570                                 const Type* val_type,
1571                                 BasicType bt,
1572                                 DecoratorSet decorators) {
1573   // Transformation of a value which could be NULL pointer (CastPP #NULL)
1574   // could be delayed during Parse (for example, in adjust_map_after_if()).
1575   // Execute transformation here to avoid barrier generation in such case.
1576   if (_gvn.type(val) == TypePtr::NULL_PTR) {
1577     val = _gvn.makecon(TypePtr::NULL_PTR);
1578   }
1579 
1580   set_control(ctl);
1581   if (stopped()) {
1582     return top(); // Dead path ?
1583   }
1584 
1585   assert(val != NULL, "not dead path");
1586 
1587   C2AccessValuePtr addr(adr, adr_type);
1588   C2AccessValue value(val, val_type);
1589   C2Access access(this, decorators | C2_WRITE_ACCESS, bt, obj, addr);
1590   if (access.is_raw()) {
1591     return _barrier_set->BarrierSetC2::store_at(access, value);
1592   } else {
1593     return _barrier_set->store_at(access, value);
1594   }
1595 }
1596 
1597 Node* GraphKit::access_load_at(Node* obj,   // containing obj
1598                                Node* adr,   // actual adress to store val at
1599                                const TypePtr* adr_type,
1600                                const Type* val_type,
1601                                BasicType bt,
1602                                DecoratorSet decorators) {
1603   if (stopped()) {
1604     return top(); // Dead path ?
1605   }
1606 
1607   C2AccessValuePtr addr(adr, adr_type);
1608   C2Access access(this, decorators | C2_READ_ACCESS, bt, obj, addr);
1609   if (access.is_raw()) {
1610     return _barrier_set->BarrierSetC2::load_at(access, val_type);
1611   } else {
1612     return _barrier_set->load_at(access, val_type);
1613   }
1614 }
1615 
1616 Node* GraphKit::access_load(Node* adr,   // actual adress to load val at
1617                             const Type* val_type,
1618                             BasicType bt,
1619                             DecoratorSet decorators) {
1620   if (stopped()) {
1621     return top(); // Dead path ?
1622   }
1623 
1624   C2AccessValuePtr addr(adr, NULL);
1625   C2Access access(this, decorators | C2_READ_ACCESS, bt, NULL, addr);
1626   if (access.is_raw()) {
1627     return _barrier_set->BarrierSetC2::load_at(access, val_type);
1628   } else {
1629     return _barrier_set->load_at(access, val_type);
1630   }
1631 }
1632 
1633 Node* GraphKit::access_atomic_cmpxchg_val_at(Node* ctl,
1634                                              Node* obj,
1635                                              Node* adr,
1636                                              const TypePtr* adr_type,
1637                                              int alias_idx,
1638                                              Node* expected_val,
1639                                              Node* new_val,
1640                                              const Type* value_type,
1641                                              BasicType bt,
1642                                              DecoratorSet decorators) {
1643   set_control(ctl);
1644   C2AccessValuePtr addr(adr, adr_type);
1645   C2AtomicAccess access(this, decorators | C2_READ_ACCESS | C2_WRITE_ACCESS,
1646                         bt, obj, addr, alias_idx);
1647   if (access.is_raw()) {
1648     return _barrier_set->BarrierSetC2::atomic_cmpxchg_val_at(access, expected_val, new_val, value_type);
1649   } else {
1650     return _barrier_set->atomic_cmpxchg_val_at(access, expected_val, new_val, value_type);
1651   }
1652 }
1653 
1654 Node* GraphKit::access_atomic_cmpxchg_bool_at(Node* ctl,
1655                                               Node* obj,
1656                                               Node* adr,
1657                                               const TypePtr* adr_type,
1658                                               int alias_idx,
1659                                               Node* expected_val,
1660                                               Node* new_val,
1661                                               const Type* value_type,
1662                                               BasicType bt,
1663                                               DecoratorSet decorators) {
1664   set_control(ctl);
1665   C2AccessValuePtr addr(adr, adr_type);
1666   C2AtomicAccess access(this, decorators | C2_READ_ACCESS | C2_WRITE_ACCESS,
1667                         bt, obj, addr, alias_idx);
1668   if (access.is_raw()) {
1669     return _barrier_set->BarrierSetC2::atomic_cmpxchg_bool_at(access, expected_val, new_val, value_type);
1670   } else {
1671     return _barrier_set->atomic_cmpxchg_bool_at(access, expected_val, new_val, value_type);
1672   }
1673 }
1674 
1675 Node* GraphKit::access_atomic_xchg_at(Node* ctl,
1676                                       Node* obj,
1677                                       Node* adr,
1678                                       const TypePtr* adr_type,
1679                                       int alias_idx,
1680                                       Node* new_val,
1681                                       const Type* value_type,
1682                                       BasicType bt,
1683                                       DecoratorSet decorators) {
1684   set_control(ctl);
1685   C2AccessValuePtr addr(adr, adr_type);
1686   C2AtomicAccess access(this, decorators | C2_READ_ACCESS | C2_WRITE_ACCESS,
1687                         bt, obj, addr, alias_idx);
1688   if (access.is_raw()) {
1689     return _barrier_set->BarrierSetC2::atomic_xchg_at(access, new_val, value_type);
1690   } else {
1691     return _barrier_set->atomic_xchg_at(access, new_val, value_type);
1692   }
1693 }
1694 
1695 Node* GraphKit::access_atomic_add_at(Node* ctl,
1696                                      Node* obj,
1697                                      Node* adr,
1698                                      const TypePtr* adr_type,
1699                                      int alias_idx,
1700                                      Node* new_val,
1701                                      const Type* value_type,
1702                                      BasicType bt,
1703                                      DecoratorSet decorators) {
1704   set_control(ctl);
1705   C2AccessValuePtr addr(adr, adr_type);
1706   C2AtomicAccess access(this, decorators | C2_READ_ACCESS | C2_WRITE_ACCESS, bt, obj, addr, alias_idx);
1707   if (access.is_raw()) {
1708     return _barrier_set->BarrierSetC2::atomic_add_at(access, new_val, value_type);
1709   } else {
1710     return _barrier_set->atomic_add_at(access, new_val, value_type);
1711   }
1712 }
1713 
1714 void GraphKit::access_clone(Node* ctl, Node* src, Node* dst, Node* size, bool is_array) {
1715   set_control(ctl);
1716   return _barrier_set->clone(this, src, dst, size, is_array);
1717 }
1718 
1719 //-------------------------array_element_address-------------------------
1720 Node* GraphKit::array_element_address(Node* ary, Node* idx, BasicType elembt,
1721                                       const TypeInt* sizetype, Node* ctrl) {
1722   uint shift  = exact_log2(type2aelembytes(elembt));
1723   uint header = arrayOopDesc::base_offset_in_bytes(elembt);
1724 
1725   // short-circuit a common case (saves lots of confusing waste motion)
1726   jint idx_con = find_int_con(idx, -1);
1727   if (idx_con >= 0) {
1728     intptr_t offset = header + ((intptr_t)idx_con << shift);
1729     return basic_plus_adr(ary, offset);
1730   }
1731 
1732   // must be correct type for alignment purposes
1733   Node* base  = basic_plus_adr(ary, header);
1734   idx = Compile::conv_I2X_index(&_gvn, idx, sizetype, ctrl);
1735   Node* scale = _gvn.transform( new LShiftXNode(idx, intcon(shift)) );
1736   return basic_plus_adr(ary, base, scale);
1737 }
1738 
1739 //-------------------------load_array_element-------------------------
1740 Node* GraphKit::load_array_element(Node* ctl, Node* ary, Node* idx, const TypeAryPtr* arytype) {
1741   const Type* elemtype = arytype->elem();
1742   BasicType elembt = elemtype->array_element_basic_type();
1743   Node* adr = array_element_address(ary, idx, elembt, arytype->size());
1744   if (elembt == T_NARROWOOP) {
1745     elembt = T_OBJECT; // To satisfy switch in LoadNode::make()
1746   }
1747   Node* ld = make_load(ctl, adr, elemtype, elembt, arytype, MemNode::unordered);
1748   return ld;
1749 }
1750 
1751 //-------------------------set_arguments_for_java_call-------------------------
1752 // Arguments (pre-popped from the stack) are taken from the JVMS.
1753 void GraphKit::set_arguments_for_java_call(CallJavaNode* call) {
1754   // Add the call arguments:
1755   uint nargs = call->method()->arg_size();
1756   for (uint i = 0; i < nargs; i++) {
1757     Node* arg = argument(i);
1758     call->init_req(i + TypeFunc::Parms, arg);
1759   }
1760 }
1761 
1762 //---------------------------set_edges_for_java_call---------------------------
1763 // Connect a newly created call into the current JVMS.
1764 // A return value node (if any) is returned from set_edges_for_java_call.
1765 void GraphKit::set_edges_for_java_call(CallJavaNode* call, bool must_throw, bool separate_io_proj) {
1766 
1767   // Add the predefined inputs:
1768   call->init_req( TypeFunc::Control, control() );
1769   call->init_req( TypeFunc::I_O    , i_o() );
1770   call->init_req( TypeFunc::Memory , reset_memory() );
1771   call->init_req( TypeFunc::FramePtr, frameptr() );
1772   call->init_req( TypeFunc::ReturnAdr, top() );
1773 
1774   add_safepoint_edges(call, must_throw);
1775 
1776   Node* xcall = _gvn.transform(call);
1777 
1778   if (xcall == top()) {
1779     set_control(top());
1780     return;
1781   }
1782   assert(xcall == call, "call identity is stable");
1783 
1784   // Re-use the current map to produce the result.
1785 
1786   set_control(_gvn.transform(new ProjNode(call, TypeFunc::Control)));
1787   set_i_o(    _gvn.transform(new ProjNode(call, TypeFunc::I_O    , separate_io_proj)));
1788   set_all_memory_call(xcall, separate_io_proj);
1789 
1790   //return xcall;   // no need, caller already has it
1791 }
1792 
1793 Node* GraphKit::set_results_for_java_call(CallJavaNode* call, bool separate_io_proj, bool deoptimize) {
1794   if (stopped())  return top();  // maybe the call folded up?
1795 
1796   // Capture the return value, if any.
1797   Node* ret;
1798   if (call->method() == NULL ||
1799       call->method()->return_type()->basic_type() == T_VOID)
1800         ret = top();
1801   else  ret = _gvn.transform(new ProjNode(call, TypeFunc::Parms));
1802 
1803   // Note:  Since any out-of-line call can produce an exception,
1804   // we always insert an I_O projection from the call into the result.
1805 
1806   make_slow_call_ex(call, env()->Throwable_klass(), separate_io_proj, deoptimize);
1807 
1808   if (separate_io_proj) {
1809     // The caller requested separate projections be used by the fall
1810     // through and exceptional paths, so replace the projections for
1811     // the fall through path.
1812     set_i_o(_gvn.transform( new ProjNode(call, TypeFunc::I_O) ));
1813     set_all_memory(_gvn.transform( new ProjNode(call, TypeFunc::Memory) ));
1814   }
1815   return ret;
1816 }
1817 
1818 //--------------------set_predefined_input_for_runtime_call--------------------
1819 // Reading and setting the memory state is way conservative here.
1820 // The real problem is that I am not doing real Type analysis on memory,
1821 // so I cannot distinguish card mark stores from other stores.  Across a GC
1822 // point the Store Barrier and the card mark memory has to agree.  I cannot
1823 // have a card mark store and its barrier split across the GC point from
1824 // either above or below.  Here I get that to happen by reading ALL of memory.
1825 // A better answer would be to separate out card marks from other memory.
1826 // For now, return the input memory state, so that it can be reused
1827 // after the call, if this call has restricted memory effects.
1828 Node* GraphKit::set_predefined_input_for_runtime_call(SafePointNode* call, Node* narrow_mem) {
1829   // Set fixed predefined input arguments
1830   Node* memory = reset_memory();
1831   Node* m = narrow_mem == NULL ? memory : narrow_mem;
1832   call->init_req( TypeFunc::Control,   control()  );
1833   call->init_req( TypeFunc::I_O,       top()      ); // does no i/o
1834   call->init_req( TypeFunc::Memory,    m          ); // may gc ptrs
1835   call->init_req( TypeFunc::FramePtr,  frameptr() );
1836   call->init_req( TypeFunc::ReturnAdr, top()      );
1837   return memory;
1838 }
1839 
1840 //-------------------set_predefined_output_for_runtime_call--------------------
1841 // Set control and memory (not i_o) from the call.
1842 // If keep_mem is not NULL, use it for the output state,
1843 // except for the RawPtr output of the call, if hook_mem is TypeRawPtr::BOTTOM.
1844 // If hook_mem is NULL, this call produces no memory effects at all.
1845 // If hook_mem is a Java-visible memory slice (such as arraycopy operands),
1846 // then only that memory slice is taken from the call.
1847 // In the last case, we must put an appropriate memory barrier before
1848 // the call, so as to create the correct anti-dependencies on loads
1849 // preceding the call.
1850 void GraphKit::set_predefined_output_for_runtime_call(Node* call,
1851                                                       Node* keep_mem,
1852                                                       const TypePtr* hook_mem) {
1853   // no i/o
1854   set_control(_gvn.transform( new ProjNode(call,TypeFunc::Control) ));
1855   if (keep_mem) {
1856     // First clone the existing memory state
1857     set_all_memory(keep_mem);
1858     if (hook_mem != NULL) {
1859       // Make memory for the call
1860       Node* mem = _gvn.transform( new ProjNode(call, TypeFunc::Memory) );
1861       // Set the RawPtr memory state only.  This covers all the heap top/GC stuff
1862       // We also use hook_mem to extract specific effects from arraycopy stubs.
1863       set_memory(mem, hook_mem);
1864     }
1865     // ...else the call has NO memory effects.
1866 
1867     // Make sure the call advertises its memory effects precisely.
1868     // This lets us build accurate anti-dependences in gcm.cpp.
1869     assert(C->alias_type(call->adr_type()) == C->alias_type(hook_mem),
1870            "call node must be constructed correctly");
1871   } else {
1872     assert(hook_mem == NULL, "");
1873     // This is not a "slow path" call; all memory comes from the call.
1874     set_all_memory_call(call);
1875   }
1876 }
1877 
1878 
1879 // Replace the call with the current state of the kit.
1880 void GraphKit::replace_call(CallNode* call, Node* result, bool do_replaced_nodes) {
1881   JVMState* ejvms = NULL;
1882   if (has_exceptions()) {
1883     ejvms = transfer_exceptions_into_jvms();
1884   }
1885 
1886   ReplacedNodes replaced_nodes = map()->replaced_nodes();
1887   ReplacedNodes replaced_nodes_exception;
1888   Node* ex_ctl = top();
1889 
1890   SafePointNode* final_state = stop();
1891 
1892   // Find all the needed outputs of this call
1893   CallProjections callprojs;
1894   call->extract_projections(&callprojs, true);
1895 
1896   Node* init_mem = call->in(TypeFunc::Memory);
1897   Node* final_mem = final_state->in(TypeFunc::Memory);
1898   Node* final_ctl = final_state->in(TypeFunc::Control);
1899   Node* final_io = final_state->in(TypeFunc::I_O);
1900 
1901   // Replace all the old call edges with the edges from the inlining result
1902   if (callprojs.fallthrough_catchproj != NULL) {
1903     C->gvn_replace_by(callprojs.fallthrough_catchproj, final_ctl);
1904   }
1905   if (callprojs.fallthrough_memproj != NULL) {
1906     if (final_mem->is_MergeMem()) {
1907       // Parser's exits MergeMem was not transformed but may be optimized
1908       final_mem = _gvn.transform(final_mem);
1909     }
1910     C->gvn_replace_by(callprojs.fallthrough_memproj,   final_mem);
1911   }
1912   if (callprojs.fallthrough_ioproj != NULL) {
1913     C->gvn_replace_by(callprojs.fallthrough_ioproj,    final_io);
1914   }
1915 
1916   // Replace the result with the new result if it exists and is used
1917   if (callprojs.resproj != NULL && result != NULL) {
1918     C->gvn_replace_by(callprojs.resproj, result);
1919   }
1920 
1921   if (ejvms == NULL) {
1922     // No exception edges to simply kill off those paths
1923     if (callprojs.catchall_catchproj != NULL) {
1924       C->gvn_replace_by(callprojs.catchall_catchproj, C->top());
1925     }
1926     if (callprojs.catchall_memproj != NULL) {
1927       C->gvn_replace_by(callprojs.catchall_memproj,   C->top());
1928     }
1929     if (callprojs.catchall_ioproj != NULL) {
1930       C->gvn_replace_by(callprojs.catchall_ioproj,    C->top());
1931     }
1932     // Replace the old exception object with top
1933     if (callprojs.exobj != NULL) {
1934       C->gvn_replace_by(callprojs.exobj, C->top());
1935     }
1936   } else {
1937     GraphKit ekit(ejvms);
1938 
1939     // Load my combined exception state into the kit, with all phis transformed:
1940     SafePointNode* ex_map = ekit.combine_and_pop_all_exception_states();
1941     replaced_nodes_exception = ex_map->replaced_nodes();
1942 
1943     Node* ex_oop = ekit.use_exception_state(ex_map);
1944 
1945     if (callprojs.catchall_catchproj != NULL) {
1946       C->gvn_replace_by(callprojs.catchall_catchproj, ekit.control());
1947       ex_ctl = ekit.control();
1948     }
1949     if (callprojs.catchall_memproj != NULL) {
1950       C->gvn_replace_by(callprojs.catchall_memproj,   ekit.reset_memory());
1951     }
1952     if (callprojs.catchall_ioproj != NULL) {
1953       C->gvn_replace_by(callprojs.catchall_ioproj,    ekit.i_o());
1954     }
1955 
1956     // Replace the old exception object with the newly created one
1957     if (callprojs.exobj != NULL) {
1958       C->gvn_replace_by(callprojs.exobj, ex_oop);
1959     }
1960   }
1961 
1962   // Disconnect the call from the graph
1963   call->disconnect_inputs(NULL, C);
1964   C->gvn_replace_by(call, C->top());
1965 
1966   // Clean up any MergeMems that feed other MergeMems since the
1967   // optimizer doesn't like that.
1968   if (final_mem->is_MergeMem()) {
1969     Node_List wl;
1970     for (SimpleDUIterator i(final_mem); i.has_next(); i.next()) {
1971       Node* m = i.get();
1972       if (m->is_MergeMem() && !wl.contains(m)) {
1973         wl.push(m);
1974       }
1975     }
1976     while (wl.size()  > 0) {
1977       _gvn.transform(wl.pop());
1978     }
1979   }
1980 
1981   if (callprojs.fallthrough_catchproj != NULL && !final_ctl->is_top() && do_replaced_nodes) {
1982     replaced_nodes.apply(C, final_ctl);
1983   }
1984   if (!ex_ctl->is_top() && do_replaced_nodes) {
1985     replaced_nodes_exception.apply(C, ex_ctl);
1986   }
1987 }
1988 
1989 
1990 //------------------------------increment_counter------------------------------
1991 // for statistics: increment a VM counter by 1
1992 
1993 void GraphKit::increment_counter(address counter_addr) {
1994   Node* adr1 = makecon(TypeRawPtr::make(counter_addr));
1995   increment_counter(adr1);
1996 }
1997 
1998 void GraphKit::increment_counter(Node* counter_addr) {
1999   int adr_type = Compile::AliasIdxRaw;
2000   Node* ctrl = control();
2001   Node* cnt  = make_load(ctrl, counter_addr, TypeInt::INT, T_INT, adr_type, MemNode::unordered);
2002   Node* incr = _gvn.transform(new AddINode(cnt, _gvn.intcon(1)));
2003   store_to_memory(ctrl, counter_addr, incr, T_INT, adr_type, MemNode::unordered);
2004 }
2005 
2006 
2007 //------------------------------uncommon_trap----------------------------------
2008 // Bail out to the interpreter in mid-method.  Implemented by calling the
2009 // uncommon_trap blob.  This helper function inserts a runtime call with the
2010 // right debug info.
2011 void GraphKit::uncommon_trap(int trap_request,
2012                              ciKlass* klass, const char* comment,
2013                              bool must_throw,
2014                              bool keep_exact_action) {
2015   if (failing())  stop();
2016   if (stopped())  return; // trap reachable?
2017 
2018   // Note:  If ProfileTraps is true, and if a deopt. actually
2019   // occurs here, the runtime will make sure an MDO exists.  There is
2020   // no need to call method()->ensure_method_data() at this point.
2021 
2022   // Set the stack pointer to the right value for reexecution:
2023   set_sp(reexecute_sp());
2024 
2025 #ifdef ASSERT
2026   if (!must_throw) {
2027     // Make sure the stack has at least enough depth to execute
2028     // the current bytecode.
2029     int inputs, ignored_depth;
2030     if (compute_stack_effects(inputs, ignored_depth)) {
2031       assert(sp() >= inputs, "must have enough JVMS stack to execute %s: sp=%d, inputs=%d",
2032              Bytecodes::name(java_bc()), sp(), inputs);
2033     }
2034   }
2035 #endif
2036 
2037   Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(trap_request);
2038   Deoptimization::DeoptAction action = Deoptimization::trap_request_action(trap_request);
2039 
2040   switch (action) {
2041   case Deoptimization::Action_maybe_recompile:
2042   case Deoptimization::Action_reinterpret:
2043     // Temporary fix for 6529811 to allow virtual calls to be sure they
2044     // get the chance to go from mono->bi->mega
2045     if (!keep_exact_action &&
2046         Deoptimization::trap_request_index(trap_request) < 0 &&
2047         too_many_recompiles(reason)) {
2048       // This BCI is causing too many recompilations.
2049       if (C->log() != NULL) {
2050         C->log()->elem("observe that='trap_action_change' reason='%s' from='%s' to='none'",
2051                 Deoptimization::trap_reason_name(reason),
2052                 Deoptimization::trap_action_name(action));
2053       }
2054       action = Deoptimization::Action_none;
2055       trap_request = Deoptimization::make_trap_request(reason, action);
2056     } else {
2057       C->set_trap_can_recompile(true);
2058     }
2059     break;
2060   case Deoptimization::Action_make_not_entrant:
2061     C->set_trap_can_recompile(true);
2062     break;
2063   case Deoptimization::Action_none:
2064   case Deoptimization::Action_make_not_compilable:
2065     break;
2066   default:
2067 #ifdef ASSERT
2068     fatal("unknown action %d: %s", action, Deoptimization::trap_action_name(action));
2069 #endif
2070     break;
2071   }
2072 
2073   if (TraceOptoParse) {
2074     char buf[100];
2075     tty->print_cr("Uncommon trap %s at bci:%d",
2076                   Deoptimization::format_trap_request(buf, sizeof(buf),
2077                                                       trap_request), bci());
2078   }
2079 
2080   CompileLog* log = C->log();
2081   if (log != NULL) {
2082     int kid = (klass == NULL)? -1: log->identify(klass);
2083     log->begin_elem("uncommon_trap bci='%d'", bci());
2084     char buf[100];
2085     log->print(" %s", Deoptimization::format_trap_request(buf, sizeof(buf),
2086                                                           trap_request));
2087     if (kid >= 0)         log->print(" klass='%d'", kid);
2088     if (comment != NULL)  log->print(" comment='%s'", comment);
2089     log->end_elem();
2090   }
2091 
2092   // Make sure any guarding test views this path as very unlikely
2093   Node *i0 = control()->in(0);
2094   if (i0 != NULL && i0->is_If()) {        // Found a guarding if test?
2095     IfNode *iff = i0->as_If();
2096     float f = iff->_prob;   // Get prob
2097     if (control()->Opcode() == Op_IfTrue) {
2098       if (f > PROB_UNLIKELY_MAG(4))
2099         iff->_prob = PROB_MIN;
2100     } else {
2101       if (f < PROB_LIKELY_MAG(4))
2102         iff->_prob = PROB_MAX;
2103     }
2104   }
2105 
2106   // Clear out dead values from the debug info.
2107   kill_dead_locals();
2108 
2109   // Now insert the uncommon trap subroutine call
2110   address call_addr = SharedRuntime::uncommon_trap_blob()->entry_point();
2111   const TypePtr* no_memory_effects = NULL;
2112   // Pass the index of the class to be loaded
2113   Node* call = make_runtime_call(RC_NO_LEAF | RC_UNCOMMON |
2114                                  (must_throw ? RC_MUST_THROW : 0),
2115                                  OptoRuntime::uncommon_trap_Type(),
2116                                  call_addr, "uncommon_trap", no_memory_effects,
2117                                  intcon(trap_request));
2118   assert(call->as_CallStaticJava()->uncommon_trap_request() == trap_request,
2119          "must extract request correctly from the graph");
2120   assert(trap_request != 0, "zero value reserved by uncommon_trap_request");
2121 
2122   call->set_req(TypeFunc::ReturnAdr, returnadr());
2123   // The debug info is the only real input to this call.
2124 
2125   // Halt-and-catch fire here.  The above call should never return!
2126   HaltNode* halt = new HaltNode(control(), frameptr(), "uncommon trap returned which should never happen"
2127                                                        PRODUCT_ONLY(COMMA /*reachable*/false));
2128   _gvn.set_type_bottom(halt);
2129   root()->add_req(halt);
2130 
2131   stop_and_kill_map();
2132 }
2133 
2134 
2135 //--------------------------just_allocated_object------------------------------
2136 // Report the object that was just allocated.
2137 // It must be the case that there are no intervening safepoints.
2138 // We use this to determine if an object is so "fresh" that
2139 // it does not require card marks.
2140 Node* GraphKit::just_allocated_object(Node* current_control) {
2141   if (C->recent_alloc_ctl() == current_control)
2142     return C->recent_alloc_obj();
2143   return NULL;
2144 }
2145 
2146 
2147 void GraphKit::round_double_arguments(ciMethod* dest_method) {
2148   // (Note:  TypeFunc::make has a cache that makes this fast.)
2149   const TypeFunc* tf    = TypeFunc::make(dest_method);
2150   int             nargs = tf->domain()->cnt() - TypeFunc::Parms;
2151   for (int j = 0; j < nargs; j++) {
2152     const Type *targ = tf->domain()->field_at(j + TypeFunc::Parms);
2153     if( targ->basic_type() == T_DOUBLE ) {
2154       // If any parameters are doubles, they must be rounded before
2155       // the call, dstore_rounding does gvn.transform
2156       Node *arg = argument(j);
2157       arg = dstore_rounding(arg);
2158       set_argument(j, arg);
2159     }
2160   }
2161 }
2162 
2163 /**
2164  * Record profiling data exact_kls for Node n with the type system so
2165  * that it can propagate it (speculation)
2166  *
2167  * @param n          node that the type applies to
2168  * @param exact_kls  type from profiling
2169  * @param maybe_null did profiling see null?
2170  *
2171  * @return           node with improved type
2172  */
2173 Node* GraphKit::record_profile_for_speculation(Node* n, ciKlass* exact_kls, ProfilePtrKind ptr_kind) {
2174   const Type* current_type = _gvn.type(n);
2175   assert(UseTypeSpeculation, "type speculation must be on");
2176 
2177   const TypePtr* speculative = current_type->speculative();
2178 
2179   // Should the klass from the profile be recorded in the speculative type?
2180   if (current_type->would_improve_type(exact_kls, jvms()->depth())) {
2181     const TypeKlassPtr* tklass = TypeKlassPtr::make(exact_kls);
2182     const TypeOopPtr* xtype = tklass->as_instance_type();
2183     assert(xtype->klass_is_exact(), "Should be exact");
2184     // Any reason to believe n is not null (from this profiling or a previous one)?
2185     assert(ptr_kind != ProfileAlwaysNull, "impossible here");
2186     const TypePtr* ptr = (ptr_kind == ProfileMaybeNull && current_type->speculative_maybe_null()) ? TypePtr::BOTTOM : TypePtr::NOTNULL;
2187     // record the new speculative type's depth
2188     speculative = xtype->cast_to_ptr_type(ptr->ptr())->is_ptr();
2189     speculative = speculative->with_inline_depth(jvms()->depth());
2190   } else if (current_type->would_improve_ptr(ptr_kind)) {
2191     // Profiling report that null was never seen so we can change the
2192     // speculative type to non null ptr.
2193     if (ptr_kind == ProfileAlwaysNull) {
2194       speculative = TypePtr::NULL_PTR;
2195     } else {
2196       assert(ptr_kind == ProfileNeverNull, "nothing else is an improvement");
2197       const TypePtr* ptr = TypePtr::NOTNULL;
2198       if (speculative != NULL) {
2199         speculative = speculative->cast_to_ptr_type(ptr->ptr())->is_ptr();
2200       } else {
2201         speculative = ptr;
2202       }
2203     }
2204   }
2205 
2206   if (speculative != current_type->speculative()) {
2207     // Build a type with a speculative type (what we think we know
2208     // about the type but will need a guard when we use it)
2209     const TypeOopPtr* spec_type = TypeOopPtr::make(TypePtr::BotPTR, Type::OffsetBot, TypeOopPtr::InstanceBot, speculative);
2210     // We're changing the type, we need a new CheckCast node to carry
2211     // the new type. The new type depends on the control: what
2212     // profiling tells us is only valid from here as far as we can
2213     // tell.
2214     Node* cast = new CheckCastPPNode(control(), n, current_type->remove_speculative()->join_speculative(spec_type));
2215     cast = _gvn.transform(cast);
2216     replace_in_map(n, cast);
2217     n = cast;
2218   }
2219 
2220   return n;
2221 }
2222 
2223 /**
2224  * Record profiling data from receiver profiling at an invoke with the
2225  * type system so that it can propagate it (speculation)
2226  *
2227  * @param n  receiver node
2228  *
2229  * @return   node with improved type
2230  */
2231 Node* GraphKit::record_profiled_receiver_for_speculation(Node* n) {
2232   if (!UseTypeSpeculation) {
2233     return n;
2234   }
2235   ciKlass* exact_kls = profile_has_unique_klass();
2236   ProfilePtrKind ptr_kind = ProfileMaybeNull;
2237   if ((java_bc() == Bytecodes::_checkcast ||
2238        java_bc() == Bytecodes::_instanceof ||
2239        java_bc() == Bytecodes::_aastore) &&
2240       method()->method_data()->is_mature()) {
2241     ciProfileData* data = method()->method_data()->bci_to_data(bci());
2242     if (data != NULL) {
2243       if (!data->as_BitData()->null_seen()) {
2244         ptr_kind = ProfileNeverNull;
2245       } else {
2246         assert(data->is_ReceiverTypeData(), "bad profile data type");
2247         ciReceiverTypeData* call = (ciReceiverTypeData*)data->as_ReceiverTypeData();
2248         uint i = 0;
2249         for (; i < call->row_limit(); i++) {
2250           ciKlass* receiver = call->receiver(i);
2251           if (receiver != NULL) {
2252             break;
2253           }
2254         }
2255         ptr_kind = (i == call->row_limit()) ? ProfileAlwaysNull : ProfileMaybeNull;
2256       }
2257     }
2258   }
2259   return record_profile_for_speculation(n, exact_kls, ptr_kind);
2260 }
2261 
2262 /**
2263  * Record profiling data from argument profiling at an invoke with the
2264  * type system so that it can propagate it (speculation)
2265  *
2266  * @param dest_method  target method for the call
2267  * @param bc           what invoke bytecode is this?
2268  */
2269 void GraphKit::record_profiled_arguments_for_speculation(ciMethod* dest_method, Bytecodes::Code bc) {
2270   if (!UseTypeSpeculation) {
2271     return;
2272   }
2273   const TypeFunc* tf    = TypeFunc::make(dest_method);
2274   int             nargs = tf->domain()->cnt() - TypeFunc::Parms;
2275   int skip = Bytecodes::has_receiver(bc) ? 1 : 0;
2276   for (int j = skip, i = 0; j < nargs && i < TypeProfileArgsLimit; j++) {
2277     const Type *targ = tf->domain()->field_at(j + TypeFunc::Parms);
2278     if (targ->basic_type() == T_OBJECT || targ->basic_type() == T_ARRAY) {
2279       ProfilePtrKind ptr_kind = ProfileMaybeNull;
2280       ciKlass* better_type = NULL;
2281       if (method()->argument_profiled_type(bci(), i, better_type, ptr_kind)) {
2282         record_profile_for_speculation(argument(j), better_type, ptr_kind);
2283       }
2284       i++;
2285     }
2286   }
2287 }
2288 
2289 /**
2290  * Record profiling data from parameter profiling at an invoke with
2291  * the type system so that it can propagate it (speculation)
2292  */
2293 void GraphKit::record_profiled_parameters_for_speculation() {
2294   if (!UseTypeSpeculation) {
2295     return;
2296   }
2297   for (int i = 0, j = 0; i < method()->arg_size() ; i++) {
2298     if (_gvn.type(local(i))->isa_oopptr()) {
2299       ProfilePtrKind ptr_kind = ProfileMaybeNull;
2300       ciKlass* better_type = NULL;
2301       if (method()->parameter_profiled_type(j, better_type, ptr_kind)) {
2302         record_profile_for_speculation(local(i), better_type, ptr_kind);
2303       }
2304       j++;
2305     }
2306   }
2307 }
2308 
2309 /**
2310  * Record profiling data from return value profiling at an invoke with
2311  * the type system so that it can propagate it (speculation)
2312  */
2313 void GraphKit::record_profiled_return_for_speculation() {
2314   if (!UseTypeSpeculation) {
2315     return;
2316   }
2317   ProfilePtrKind ptr_kind = ProfileMaybeNull;
2318   ciKlass* better_type = NULL;
2319   if (method()->return_profiled_type(bci(), better_type, ptr_kind)) {
2320     // If profiling reports a single type for the return value,
2321     // feed it to the type system so it can propagate it as a
2322     // speculative type
2323     record_profile_for_speculation(stack(sp()-1), better_type, ptr_kind);
2324   }
2325 }
2326 
2327 void GraphKit::round_double_result(ciMethod* dest_method) {
2328   // A non-strict method may return a double value which has an extended
2329   // exponent, but this must not be visible in a caller which is 'strict'
2330   // If a strict caller invokes a non-strict callee, round a double result
2331 
2332   BasicType result_type = dest_method->return_type()->basic_type();
2333   assert( method() != NULL, "must have caller context");
2334   if( result_type == T_DOUBLE && method()->is_strict() && !dest_method->is_strict() ) {
2335     // Destination method's return value is on top of stack
2336     // dstore_rounding() does gvn.transform
2337     Node *result = pop_pair();
2338     result = dstore_rounding(result);
2339     push_pair(result);
2340   }
2341 }
2342 
2343 // rounding for strict float precision conformance
2344 Node* GraphKit::precision_rounding(Node* n) {
2345   return UseStrictFP && _method->flags().is_strict()
2346     && UseSSE == 0 && Matcher::strict_fp_requires_explicit_rounding
2347     ? _gvn.transform( new RoundFloatNode(0, n) )
2348     : n;
2349 }
2350 
2351 // rounding for strict double precision conformance
2352 Node* GraphKit::dprecision_rounding(Node *n) {
2353   return UseStrictFP && _method->flags().is_strict()
2354     && UseSSE <= 1 && Matcher::strict_fp_requires_explicit_rounding
2355     ? _gvn.transform( new RoundDoubleNode(0, n) )
2356     : n;
2357 }
2358 
2359 // rounding for non-strict double stores
2360 Node* GraphKit::dstore_rounding(Node* n) {
2361   return Matcher::strict_fp_requires_explicit_rounding
2362     && UseSSE <= 1
2363     ? _gvn.transform( new RoundDoubleNode(0, n) )
2364     : n;
2365 }
2366 
2367 //=============================================================================
2368 // Generate a fast path/slow path idiom.  Graph looks like:
2369 // [foo] indicates that 'foo' is a parameter
2370 //
2371 //              [in]     NULL
2372 //                 \    /
2373 //                  CmpP
2374 //                  Bool ne
2375 //                   If
2376 //                  /  \
2377 //              True    False-<2>
2378 //              / |
2379 //             /  cast_not_null
2380 //           Load  |    |   ^
2381 //        [fast_test]   |   |
2382 // gvn to   opt_test    |   |
2383 //          /    \      |  <1>
2384 //      True     False  |
2385 //        |         \\  |
2386 //   [slow_call]     \[fast_result]
2387 //    Ctl   Val       \      \
2388 //     |               \      \
2389 //    Catch       <1>   \      \
2390 //   /    \        ^     \      \
2391 //  Ex    No_Ex    |      \      \
2392 //  |       \   \  |       \ <2>  \
2393 //  ...      \  [slow_res] |  |    \   [null_result]
2394 //            \         \--+--+---  |  |
2395 //             \           | /    \ | /
2396 //              --------Region     Phi
2397 //
2398 //=============================================================================
2399 // Code is structured as a series of driver functions all called 'do_XXX' that
2400 // call a set of helper functions.  Helper functions first, then drivers.
2401 
2402 //------------------------------null_check_oop---------------------------------
2403 // Null check oop.  Set null-path control into Region in slot 3.
2404 // Make a cast-not-nullness use the other not-null control.  Return cast.
2405 Node* GraphKit::null_check_oop(Node* value, Node* *null_control,
2406                                bool never_see_null,
2407                                bool safe_for_replace,
2408                                bool speculative) {
2409   // Initial NULL check taken path
2410   (*null_control) = top();
2411   Node* cast = null_check_common(value, T_OBJECT, false, null_control, speculative);
2412 
2413   // Generate uncommon_trap:
2414   if (never_see_null && (*null_control) != top()) {
2415     // If we see an unexpected null at a check-cast we record it and force a
2416     // recompile; the offending check-cast will be compiled to handle NULLs.
2417     // If we see more than one offending BCI, then all checkcasts in the
2418     // method will be compiled to handle NULLs.
2419     PreserveJVMState pjvms(this);
2420     set_control(*null_control);
2421     replace_in_map(value, null());
2422     Deoptimization::DeoptReason reason = Deoptimization::reason_null_check(speculative);
2423     uncommon_trap(reason,
2424                   Deoptimization::Action_make_not_entrant);
2425     (*null_control) = top();    // NULL path is dead
2426   }
2427   if ((*null_control) == top() && safe_for_replace) {
2428     replace_in_map(value, cast);
2429   }
2430 
2431   // Cast away null-ness on the result
2432   return cast;
2433 }
2434 
2435 //------------------------------opt_iff----------------------------------------
2436 // Optimize the fast-check IfNode.  Set the fast-path region slot 2.
2437 // Return slow-path control.
2438 Node* GraphKit::opt_iff(Node* region, Node* iff) {
2439   IfNode *opt_iff = _gvn.transform(iff)->as_If();
2440 
2441   // Fast path taken; set region slot 2
2442   Node *fast_taken = _gvn.transform( new IfFalseNode(opt_iff) );
2443   region->init_req(2,fast_taken); // Capture fast-control
2444 
2445   // Fast path not-taken, i.e. slow path
2446   Node *slow_taken = _gvn.transform( new IfTrueNode(opt_iff) );
2447   return slow_taken;
2448 }
2449 
2450 //-----------------------------make_runtime_call-------------------------------
2451 Node* GraphKit::make_runtime_call(int flags,
2452                                   const TypeFunc* call_type, address call_addr,
2453                                   const char* call_name,
2454                                   const TypePtr* adr_type,
2455                                   // The following parms are all optional.
2456                                   // The first NULL ends the list.
2457                                   Node* parm0, Node* parm1,
2458                                   Node* parm2, Node* parm3,
2459                                   Node* parm4, Node* parm5,
2460                                   Node* parm6, Node* parm7) {
2461   assert(call_addr != NULL, "must not call NULL targets");
2462 
2463   // Slow-path call
2464   bool is_leaf = !(flags & RC_NO_LEAF);
2465   bool has_io  = (!is_leaf && !(flags & RC_NO_IO));
2466   if (call_name == NULL) {
2467     assert(!is_leaf, "must supply name for leaf");
2468     call_name = OptoRuntime::stub_name(call_addr);
2469   }
2470   CallNode* call;
2471   if (!is_leaf) {
2472     call = new CallStaticJavaNode(call_type, call_addr, call_name,
2473                                            bci(), adr_type);
2474   } else if (flags & RC_NO_FP) {
2475     call = new CallLeafNoFPNode(call_type, call_addr, call_name, adr_type);
2476   } else {
2477     call = new CallLeafNode(call_type, call_addr, call_name, adr_type);
2478   }
2479 
2480   // The following is similar to set_edges_for_java_call,
2481   // except that the memory effects of the call are restricted to AliasIdxRaw.
2482 
2483   // Slow path call has no side-effects, uses few values
2484   bool wide_in  = !(flags & RC_NARROW_MEM);
2485   bool wide_out = (C->get_alias_index(adr_type) == Compile::AliasIdxBot);
2486 
2487   Node* prev_mem = NULL;
2488   if (wide_in) {
2489     prev_mem = set_predefined_input_for_runtime_call(call);
2490   } else {
2491     assert(!wide_out, "narrow in => narrow out");
2492     Node* narrow_mem = memory(adr_type);
2493     prev_mem = set_predefined_input_for_runtime_call(call, narrow_mem);
2494   }
2495 
2496   // Hook each parm in order.  Stop looking at the first NULL.
2497   if (parm0 != NULL) { call->init_req(TypeFunc::Parms+0, parm0);
2498   if (parm1 != NULL) { call->init_req(TypeFunc::Parms+1, parm1);
2499   if (parm2 != NULL) { call->init_req(TypeFunc::Parms+2, parm2);
2500   if (parm3 != NULL) { call->init_req(TypeFunc::Parms+3, parm3);
2501   if (parm4 != NULL) { call->init_req(TypeFunc::Parms+4, parm4);
2502   if (parm5 != NULL) { call->init_req(TypeFunc::Parms+5, parm5);
2503   if (parm6 != NULL) { call->init_req(TypeFunc::Parms+6, parm6);
2504   if (parm7 != NULL) { call->init_req(TypeFunc::Parms+7, parm7);
2505     /* close each nested if ===> */  } } } } } } } }
2506   assert(call->in(call->req()-1) != NULL, "must initialize all parms");
2507 
2508   if (!is_leaf) {
2509     // Non-leaves can block and take safepoints:
2510     add_safepoint_edges(call, ((flags & RC_MUST_THROW) != 0));
2511   }
2512   // Non-leaves can throw exceptions:
2513   if (has_io) {
2514     call->set_req(TypeFunc::I_O, i_o());
2515   }
2516 
2517   if (flags & RC_UNCOMMON) {
2518     // Set the count to a tiny probability.  Cf. Estimate_Block_Frequency.
2519     // (An "if" probability corresponds roughly to an unconditional count.
2520     // Sort of.)
2521     call->set_cnt(PROB_UNLIKELY_MAG(4));
2522   }
2523 
2524   Node* c = _gvn.transform(call);
2525   assert(c == call, "cannot disappear");
2526 
2527   if (wide_out) {
2528     // Slow path call has full side-effects.
2529     set_predefined_output_for_runtime_call(call);
2530   } else {
2531     // Slow path call has few side-effects, and/or sets few values.
2532     set_predefined_output_for_runtime_call(call, prev_mem, adr_type);
2533   }
2534 
2535   if (has_io) {
2536     set_i_o(_gvn.transform(new ProjNode(call, TypeFunc::I_O)));
2537   }
2538   return call;
2539 
2540 }
2541 
2542 //------------------------------merge_memory-----------------------------------
2543 // Merge memory from one path into the current memory state.
2544 void GraphKit::merge_memory(Node* new_mem, Node* region, int new_path) {
2545   for (MergeMemStream mms(merged_memory(), new_mem->as_MergeMem()); mms.next_non_empty2(); ) {
2546     Node* old_slice = mms.force_memory();
2547     Node* new_slice = mms.memory2();
2548     if (old_slice != new_slice) {
2549       PhiNode* phi;
2550       if (old_slice->is_Phi() && old_slice->as_Phi()->region() == region) {
2551         if (mms.is_empty()) {
2552           // clone base memory Phi's inputs for this memory slice
2553           assert(old_slice == mms.base_memory(), "sanity");
2554           phi = PhiNode::make(region, NULL, Type::MEMORY, mms.adr_type(C));
2555           _gvn.set_type(phi, Type::MEMORY);
2556           for (uint i = 1; i < phi->req(); i++) {
2557             phi->init_req(i, old_slice->in(i));
2558           }
2559         } else {
2560           phi = old_slice->as_Phi(); // Phi was generated already
2561         }
2562       } else {
2563         phi = PhiNode::make(region, old_slice, Type::MEMORY, mms.adr_type(C));
2564         _gvn.set_type(phi, Type::MEMORY);
2565       }
2566       phi->set_req(new_path, new_slice);
2567       mms.set_memory(phi);
2568     }
2569   }
2570 }
2571 
2572 //------------------------------make_slow_call_ex------------------------------
2573 // Make the exception handler hookups for the slow call
2574 void GraphKit::make_slow_call_ex(Node* call, ciInstanceKlass* ex_klass, bool separate_io_proj, bool deoptimize) {
2575   if (stopped())  return;
2576 
2577   // Make a catch node with just two handlers:  fall-through and catch-all
2578   Node* i_o  = _gvn.transform( new ProjNode(call, TypeFunc::I_O, separate_io_proj) );
2579   Node* catc = _gvn.transform( new CatchNode(control(), i_o, 2) );
2580   Node* norm = _gvn.transform( new CatchProjNode(catc, CatchProjNode::fall_through_index, CatchProjNode::no_handler_bci) );
2581   Node* excp = _gvn.transform( new CatchProjNode(catc, CatchProjNode::catch_all_index,    CatchProjNode::no_handler_bci) );
2582 
2583   { PreserveJVMState pjvms(this);
2584     set_control(excp);
2585     set_i_o(i_o);
2586 
2587     if (excp != top()) {
2588       if (deoptimize) {
2589         // Deoptimize if an exception is caught. Don't construct exception state in this case.
2590         uncommon_trap(Deoptimization::Reason_unhandled,
2591                       Deoptimization::Action_none);
2592       } else {
2593         // Create an exception state also.
2594         // Use an exact type if the caller has a specific exception.
2595         const Type* ex_type = TypeOopPtr::make_from_klass_unique(ex_klass)->cast_to_ptr_type(TypePtr::NotNull);
2596         Node*       ex_oop  = new CreateExNode(ex_type, control(), i_o);
2597         add_exception_state(make_exception_state(_gvn.transform(ex_oop)));
2598       }
2599     }
2600   }
2601 
2602   // Get the no-exception control from the CatchNode.
2603   set_control(norm);
2604 }
2605 
2606 static IfNode* gen_subtype_check_compare(Node* ctrl, Node* in1, Node* in2, BoolTest::mask test, float p, PhaseGVN* gvn, BasicType bt) {
2607   Node* cmp = NULL;
2608   switch(bt) {
2609   case T_INT: cmp = new CmpINode(in1, in2); break;
2610   case T_ADDRESS: cmp = new CmpPNode(in1, in2); break;
2611   default: fatal("unexpected comparison type %s", type2name(bt));
2612   }
2613   gvn->transform(cmp);
2614   Node* bol = gvn->transform(new BoolNode(cmp, test));
2615   IfNode* iff = new IfNode(ctrl, bol, p, COUNT_UNKNOWN);
2616   gvn->transform(iff);
2617   if (!bol->is_Con()) gvn->record_for_igvn(iff);
2618   return iff;
2619 }
2620 
2621 
2622 //-------------------------------gen_subtype_check-----------------------------
2623 // Generate a subtyping check.  Takes as input the subtype and supertype.
2624 // Returns 2 values: sets the default control() to the true path and returns
2625 // the false path.  Only reads invariant memory; sets no (visible) memory.
2626 // The PartialSubtypeCheckNode sets the hidden 1-word cache in the encoding
2627 // but that's not exposed to the optimizer.  This call also doesn't take in an
2628 // Object; if you wish to check an Object you need to load the Object's class
2629 // prior to coming here.
2630 Node* Phase::gen_subtype_check(Node* subklass, Node* superklass, Node** ctrl, MergeMemNode* mem, PhaseGVN* gvn) {
2631   Compile* C = gvn->C;
2632 
2633   if ((*ctrl)->is_top()) {
2634     return C->top();
2635   }
2636 
2637   // Fast check for identical types, perhaps identical constants.
2638   // The types can even be identical non-constants, in cases
2639   // involving Array.newInstance, Object.clone, etc.
2640   if (subklass == superklass)
2641     return C->top();             // false path is dead; no test needed.
2642 
2643   if (gvn->type(superklass)->singleton()) {
2644     ciKlass* superk = gvn->type(superklass)->is_klassptr()->klass();
2645     ciKlass* subk   = gvn->type(subklass)->is_klassptr()->klass();
2646 
2647     // In the common case of an exact superklass, try to fold up the
2648     // test before generating code.  You may ask, why not just generate
2649     // the code and then let it fold up?  The answer is that the generated
2650     // code will necessarily include null checks, which do not always
2651     // completely fold away.  If they are also needless, then they turn
2652     // into a performance loss.  Example:
2653     //    Foo[] fa = blah(); Foo x = fa[0]; fa[1] = x;
2654     // Here, the type of 'fa' is often exact, so the store check
2655     // of fa[1]=x will fold up, without testing the nullness of x.
2656     switch (C->static_subtype_check(superk, subk)) {
2657     case Compile::SSC_always_false:
2658       {
2659         Node* always_fail = *ctrl;
2660         *ctrl = gvn->C->top();
2661         return always_fail;
2662       }
2663     case Compile::SSC_always_true:
2664       return C->top();
2665     case Compile::SSC_easy_test:
2666       {
2667         // Just do a direct pointer compare and be done.
2668         IfNode* iff = gen_subtype_check_compare(*ctrl, subklass, superklass, BoolTest::eq, PROB_STATIC_FREQUENT, gvn, T_ADDRESS);
2669         *ctrl = gvn->transform(new IfTrueNode(iff));
2670         return gvn->transform(new IfFalseNode(iff));
2671       }
2672     case Compile::SSC_full_test:
2673       break;
2674     default:
2675       ShouldNotReachHere();
2676     }
2677   }
2678 
2679   // %%% Possible further optimization:  Even if the superklass is not exact,
2680   // if the subklass is the unique subtype of the superklass, the check
2681   // will always succeed.  We could leave a dependency behind to ensure this.
2682 
2683   // First load the super-klass's check-offset
2684   Node *p1 = gvn->transform(new AddPNode(superklass, superklass, gvn->MakeConX(in_bytes(Klass::super_check_offset_offset()))));
2685   Node* m = mem->memory_at(C->get_alias_index(gvn->type(p1)->is_ptr()));
2686   Node *chk_off = gvn->transform(new LoadINode(NULL, m, p1, gvn->type(p1)->is_ptr(), TypeInt::INT, MemNode::unordered));
2687   int cacheoff_con = in_bytes(Klass::secondary_super_cache_offset());
2688   bool might_be_cache = (gvn->find_int_con(chk_off, cacheoff_con) == cacheoff_con);
2689 
2690   // Load from the sub-klass's super-class display list, or a 1-word cache of
2691   // the secondary superclass list, or a failing value with a sentinel offset
2692   // if the super-klass is an interface or exceptionally deep in the Java
2693   // hierarchy and we have to scan the secondary superclass list the hard way.
2694   // Worst-case type is a little odd: NULL is allowed as a result (usually
2695   // klass loads can never produce a NULL).
2696   Node *chk_off_X = chk_off;
2697 #ifdef _LP64
2698   chk_off_X = gvn->transform(new ConvI2LNode(chk_off_X));
2699 #endif
2700   Node *p2 = gvn->transform(new AddPNode(subklass,subklass,chk_off_X));
2701   // For some types like interfaces the following loadKlass is from a 1-word
2702   // cache which is mutable so can't use immutable memory.  Other
2703   // types load from the super-class display table which is immutable.
2704   m = mem->memory_at(C->get_alias_index(gvn->type(p2)->is_ptr()));
2705   Node *kmem = might_be_cache ? m : C->immutable_memory();
2706   Node *nkls = gvn->transform(LoadKlassNode::make(*gvn, NULL, kmem, p2, gvn->type(p2)->is_ptr(), TypeKlassPtr::OBJECT_OR_NULL));
2707 
2708   // Compile speed common case: ARE a subtype and we canNOT fail
2709   if( superklass == nkls )
2710     return C->top();             // false path is dead; no test needed.
2711 
2712   // See if we get an immediate positive hit.  Happens roughly 83% of the
2713   // time.  Test to see if the value loaded just previously from the subklass
2714   // is exactly the superklass.
2715   IfNode *iff1 = gen_subtype_check_compare(*ctrl, superklass, nkls, BoolTest::eq, PROB_LIKELY(0.83f), gvn, T_ADDRESS);
2716   Node *iftrue1 = gvn->transform( new IfTrueNode (iff1));
2717   *ctrl = gvn->transform(new IfFalseNode(iff1));
2718 
2719   // Compile speed common case: Check for being deterministic right now.  If
2720   // chk_off is a constant and not equal to cacheoff then we are NOT a
2721   // subklass.  In this case we need exactly the 1 test above and we can
2722   // return those results immediately.
2723   if (!might_be_cache) {
2724     Node* not_subtype_ctrl = *ctrl;
2725     *ctrl = iftrue1; // We need exactly the 1 test above
2726     return not_subtype_ctrl;
2727   }
2728 
2729   // Gather the various success & failures here
2730   RegionNode *r_ok_subtype = new RegionNode(4);
2731   gvn->record_for_igvn(r_ok_subtype);
2732   RegionNode *r_not_subtype = new RegionNode(3);
2733   gvn->record_for_igvn(r_not_subtype);
2734 
2735   r_ok_subtype->init_req(1, iftrue1);
2736 
2737   // Check for immediate negative hit.  Happens roughly 11% of the time (which
2738   // is roughly 63% of the remaining cases).  Test to see if the loaded
2739   // check-offset points into the subklass display list or the 1-element
2740   // cache.  If it points to the display (and NOT the cache) and the display
2741   // missed then it's not a subtype.
2742   Node *cacheoff = gvn->intcon(cacheoff_con);
2743   IfNode *iff2 = gen_subtype_check_compare(*ctrl, chk_off, cacheoff, BoolTest::ne, PROB_LIKELY(0.63f), gvn, T_INT);
2744   r_not_subtype->init_req(1, gvn->transform(new IfTrueNode (iff2)));
2745   *ctrl = gvn->transform(new IfFalseNode(iff2));
2746 
2747   // Check for self.  Very rare to get here, but it is taken 1/3 the time.
2748   // No performance impact (too rare) but allows sharing of secondary arrays
2749   // which has some footprint reduction.
2750   IfNode *iff3 = gen_subtype_check_compare(*ctrl, subklass, superklass, BoolTest::eq, PROB_LIKELY(0.36f), gvn, T_ADDRESS);
2751   r_ok_subtype->init_req(2, gvn->transform(new IfTrueNode(iff3)));
2752   *ctrl = gvn->transform(new IfFalseNode(iff3));
2753 
2754   // -- Roads not taken here: --
2755   // We could also have chosen to perform the self-check at the beginning
2756   // of this code sequence, as the assembler does.  This would not pay off
2757   // the same way, since the optimizer, unlike the assembler, can perform
2758   // static type analysis to fold away many successful self-checks.
2759   // Non-foldable self checks work better here in second position, because
2760   // the initial primary superclass check subsumes a self-check for most
2761   // types.  An exception would be a secondary type like array-of-interface,
2762   // which does not appear in its own primary supertype display.
2763   // Finally, we could have chosen to move the self-check into the
2764   // PartialSubtypeCheckNode, and from there out-of-line in a platform
2765   // dependent manner.  But it is worthwhile to have the check here,
2766   // where it can be perhaps be optimized.  The cost in code space is
2767   // small (register compare, branch).
2768 
2769   // Now do a linear scan of the secondary super-klass array.  Again, no real
2770   // performance impact (too rare) but it's gotta be done.
2771   // Since the code is rarely used, there is no penalty for moving it
2772   // out of line, and it can only improve I-cache density.
2773   // The decision to inline or out-of-line this final check is platform
2774   // dependent, and is found in the AD file definition of PartialSubtypeCheck.
2775   Node* psc = gvn->transform(
2776     new PartialSubtypeCheckNode(*ctrl, subklass, superklass));
2777 
2778   IfNode *iff4 = gen_subtype_check_compare(*ctrl, psc, gvn->zerocon(T_OBJECT), BoolTest::ne, PROB_FAIR, gvn, T_ADDRESS);
2779   r_not_subtype->init_req(2, gvn->transform(new IfTrueNode (iff4)));
2780   r_ok_subtype ->init_req(3, gvn->transform(new IfFalseNode(iff4)));
2781 
2782   // Return false path; set default control to true path.
2783   *ctrl = gvn->transform(r_ok_subtype);
2784   return gvn->transform(r_not_subtype);
2785 }
2786 
2787 // Profile-driven exact type check:
2788 Node* GraphKit::type_check_receiver(Node* receiver, ciKlass* klass,
2789                                     float prob,
2790                                     Node* *casted_receiver) {
2791   const TypeKlassPtr* tklass = TypeKlassPtr::make(klass);
2792   Node* recv_klass = load_object_klass(receiver);
2793   Node* want_klass = makecon(tklass);
2794   Node* cmp = _gvn.transform( new CmpPNode(recv_klass, want_klass) );
2795   Node* bol = _gvn.transform( new BoolNode(cmp, BoolTest::eq) );
2796   IfNode* iff = create_and_xform_if(control(), bol, prob, COUNT_UNKNOWN);
2797   set_control( _gvn.transform( new IfTrueNode (iff) ));
2798   Node* fail = _gvn.transform( new IfFalseNode(iff) );
2799 
2800   const TypeOopPtr* recv_xtype = tklass->as_instance_type();
2801   assert(recv_xtype->klass_is_exact(), "");
2802 
2803   // Subsume downstream occurrences of receiver with a cast to
2804   // recv_xtype, since now we know what the type will be.
2805   Node* cast = new CheckCastPPNode(control(), receiver, recv_xtype);
2806   (*casted_receiver) = _gvn.transform(cast);
2807   // (User must make the replace_in_map call.)
2808 
2809   return fail;
2810 }
2811 
2812 
2813 //------------------------------seems_never_null-------------------------------
2814 // Use null_seen information if it is available from the profile.
2815 // If we see an unexpected null at a type check we record it and force a
2816 // recompile; the offending check will be recompiled to handle NULLs.
2817 // If we see several offending BCIs, then all checks in the
2818 // method will be recompiled.
2819 bool GraphKit::seems_never_null(Node* obj, ciProfileData* data, bool& speculating) {
2820   speculating = !_gvn.type(obj)->speculative_maybe_null();
2821   Deoptimization::DeoptReason reason = Deoptimization::reason_null_check(speculating);
2822   if (UncommonNullCast               // Cutout for this technique
2823       && obj != null()               // And not the -Xcomp stupid case?
2824       && !too_many_traps(reason)
2825       ) {
2826     if (speculating) {
2827       return true;
2828     }
2829     if (data == NULL)
2830       // Edge case:  no mature data.  Be optimistic here.
2831       return true;
2832     // If the profile has not seen a null, assume it won't happen.
2833     assert(java_bc() == Bytecodes::_checkcast ||
2834            java_bc() == Bytecodes::_instanceof ||
2835            java_bc() == Bytecodes::_aastore, "MDO must collect null_seen bit here");
2836     return !data->as_BitData()->null_seen();
2837   }
2838   speculating = false;
2839   return false;
2840 }
2841 
2842 //------------------------maybe_cast_profiled_receiver-------------------------
2843 // If the profile has seen exactly one type, narrow to exactly that type.
2844 // Subsequent type checks will always fold up.
2845 Node* GraphKit::maybe_cast_profiled_receiver(Node* not_null_obj,
2846                                              ciKlass* require_klass,
2847                                              ciKlass* spec_klass,
2848                                              bool safe_for_replace) {
2849   if (!UseTypeProfile || !TypeProfileCasts) return NULL;
2850 
2851   Deoptimization::DeoptReason reason = Deoptimization::reason_class_check(spec_klass != NULL);
2852 
2853   // Make sure we haven't already deoptimized from this tactic.
2854   if (too_many_traps_or_recompiles(reason))
2855     return NULL;
2856 
2857   // (No, this isn't a call, but it's enough like a virtual call
2858   // to use the same ciMethod accessor to get the profile info...)
2859   // If we have a speculative type use it instead of profiling (which
2860   // may not help us)
2861   ciKlass* exact_kls = spec_klass == NULL ? profile_has_unique_klass() : spec_klass;
2862   if (exact_kls != NULL) {// no cast failures here
2863     if (require_klass == NULL ||
2864         C->static_subtype_check(require_klass, exact_kls) == Compile::SSC_always_true) {
2865       // If we narrow the type to match what the type profile sees or
2866       // the speculative type, we can then remove the rest of the
2867       // cast.
2868       // This is a win, even if the exact_kls is very specific,
2869       // because downstream operations, such as method calls,
2870       // will often benefit from the sharper type.
2871       Node* exact_obj = not_null_obj; // will get updated in place...
2872       Node* slow_ctl  = type_check_receiver(exact_obj, exact_kls, 1.0,
2873                                             &exact_obj);
2874       { PreserveJVMState pjvms(this);
2875         set_control(slow_ctl);
2876         uncommon_trap_exact(reason, Deoptimization::Action_maybe_recompile);
2877       }
2878       if (safe_for_replace) {
2879         replace_in_map(not_null_obj, exact_obj);
2880       }
2881       return exact_obj;
2882     }
2883     // assert(ssc == Compile::SSC_always_true)... except maybe the profile lied to us.
2884   }
2885 
2886   return NULL;
2887 }
2888 
2889 /**
2890  * Cast obj to type and emit guard unless we had too many traps here
2891  * already
2892  *
2893  * @param obj       node being casted
2894  * @param type      type to cast the node to
2895  * @param not_null  true if we know node cannot be null
2896  */
2897 Node* GraphKit::maybe_cast_profiled_obj(Node* obj,
2898                                         ciKlass* type,
2899                                         bool not_null) {
2900   if (stopped()) {
2901     return obj;
2902   }
2903 
2904   // type == NULL if profiling tells us this object is always null
2905   if (type != NULL) {
2906     Deoptimization::DeoptReason class_reason = Deoptimization::Reason_speculate_class_check;
2907     Deoptimization::DeoptReason null_reason = Deoptimization::Reason_speculate_null_check;
2908 
2909     if (!too_many_traps_or_recompiles(null_reason) &&
2910         !too_many_traps_or_recompiles(class_reason)) {
2911       Node* not_null_obj = NULL;
2912       // not_null is true if we know the object is not null and
2913       // there's no need for a null check
2914       if (!not_null) {
2915         Node* null_ctl = top();
2916         not_null_obj = null_check_oop(obj, &null_ctl, true, true, true);
2917         assert(null_ctl->is_top(), "no null control here");
2918       } else {
2919         not_null_obj = obj;
2920       }
2921 
2922       Node* exact_obj = not_null_obj;
2923       ciKlass* exact_kls = type;
2924       Node* slow_ctl  = type_check_receiver(exact_obj, exact_kls, 1.0,
2925                                             &exact_obj);
2926       {
2927         PreserveJVMState pjvms(this);
2928         set_control(slow_ctl);
2929         uncommon_trap_exact(class_reason, Deoptimization::Action_maybe_recompile);
2930       }
2931       replace_in_map(not_null_obj, exact_obj);
2932       obj = exact_obj;
2933     }
2934   } else {
2935     if (!too_many_traps_or_recompiles(Deoptimization::Reason_null_assert)) {
2936       Node* exact_obj = null_assert(obj);
2937       replace_in_map(obj, exact_obj);
2938       obj = exact_obj;
2939     }
2940   }
2941   return obj;
2942 }
2943 
2944 //-------------------------------gen_instanceof--------------------------------
2945 // Generate an instance-of idiom.  Used by both the instance-of bytecode
2946 // and the reflective instance-of call.
2947 Node* GraphKit::gen_instanceof(Node* obj, Node* superklass, bool safe_for_replace) {
2948   kill_dead_locals();           // Benefit all the uncommon traps
2949   assert( !stopped(), "dead parse path should be checked in callers" );
2950   assert(!TypePtr::NULL_PTR->higher_equal(_gvn.type(superklass)->is_klassptr()),
2951          "must check for not-null not-dead klass in callers");
2952 
2953   // Make the merge point
2954   enum { _obj_path = 1, _fail_path, _null_path, PATH_LIMIT };
2955   RegionNode* region = new RegionNode(PATH_LIMIT);
2956   Node*       phi    = new PhiNode(region, TypeInt::BOOL);
2957   C->set_has_split_ifs(true); // Has chance for split-if optimization
2958 
2959   ciProfileData* data = NULL;
2960   if (java_bc() == Bytecodes::_instanceof) {  // Only for the bytecode
2961     data = method()->method_data()->bci_to_data(bci());
2962   }
2963   bool speculative_not_null = false;
2964   bool never_see_null = (ProfileDynamicTypes  // aggressive use of profile
2965                          && seems_never_null(obj, data, speculative_not_null));
2966 
2967   // Null check; get casted pointer; set region slot 3
2968   Node* null_ctl = top();
2969   Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null, safe_for_replace, speculative_not_null);
2970 
2971   // If not_null_obj is dead, only null-path is taken
2972   if (stopped()) {              // Doing instance-of on a NULL?
2973     set_control(null_ctl);
2974     return intcon(0);
2975   }
2976   region->init_req(_null_path, null_ctl);
2977   phi   ->init_req(_null_path, intcon(0)); // Set null path value
2978   if (null_ctl == top()) {
2979     // Do this eagerly, so that pattern matches like is_diamond_phi
2980     // will work even during parsing.
2981     assert(_null_path == PATH_LIMIT-1, "delete last");
2982     region->del_req(_null_path);
2983     phi   ->del_req(_null_path);
2984   }
2985 
2986   // Do we know the type check always succeed?
2987   bool known_statically = false;
2988   if (_gvn.type(superklass)->singleton()) {
2989     ciKlass* superk = _gvn.type(superklass)->is_klassptr()->klass();
2990     ciKlass* subk = _gvn.type(obj)->is_oopptr()->klass();
2991     if (subk != NULL && subk->is_loaded()) {
2992       int static_res = C->static_subtype_check(superk, subk);
2993       known_statically = (static_res == Compile::SSC_always_true || static_res == Compile::SSC_always_false);
2994     }
2995   }
2996 
2997   if (!known_statically) {
2998     const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
2999     // We may not have profiling here or it may not help us. If we
3000     // have a speculative type use it to perform an exact cast.
3001     ciKlass* spec_obj_type = obj_type->speculative_type();
3002     if (spec_obj_type != NULL || (ProfileDynamicTypes && data != NULL)) {
3003       Node* cast_obj = maybe_cast_profiled_receiver(not_null_obj, NULL, spec_obj_type, safe_for_replace);
3004       if (stopped()) {            // Profile disagrees with this path.
3005         set_control(null_ctl);    // Null is the only remaining possibility.
3006         return intcon(0);
3007       }
3008       if (cast_obj != NULL) {
3009         not_null_obj = cast_obj;
3010       }
3011     }
3012   }
3013 
3014   // Load the object's klass
3015   Node* obj_klass = load_object_klass(not_null_obj);
3016 
3017   // Generate the subtype check
3018   Node* not_subtype_ctrl = gen_subtype_check(obj_klass, superklass);
3019 
3020   // Plug in the success path to the general merge in slot 1.
3021   region->init_req(_obj_path, control());
3022   phi   ->init_req(_obj_path, intcon(1));
3023 
3024   // Plug in the failing path to the general merge in slot 2.
3025   region->init_req(_fail_path, not_subtype_ctrl);
3026   phi   ->init_req(_fail_path, intcon(0));
3027 
3028   // Return final merged results
3029   set_control( _gvn.transform(region) );
3030   record_for_igvn(region);
3031 
3032   // If we know the type check always succeeds then we don't use the
3033   // profiling data at this bytecode. Don't lose it, feed it to the
3034   // type system as a speculative type.
3035   if (safe_for_replace) {
3036     Node* casted_obj = record_profiled_receiver_for_speculation(obj);
3037     replace_in_map(obj, casted_obj);
3038   }
3039 
3040   return _gvn.transform(phi);
3041 }
3042 
3043 //-------------------------------gen_checkcast---------------------------------
3044 // Generate a checkcast idiom.  Used by both the checkcast bytecode and the
3045 // array store bytecode.  Stack must be as-if BEFORE doing the bytecode so the
3046 // uncommon-trap paths work.  Adjust stack after this call.
3047 // If failure_control is supplied and not null, it is filled in with
3048 // the control edge for the cast failure.  Otherwise, an appropriate
3049 // uncommon trap or exception is thrown.
3050 Node* GraphKit::gen_checkcast(Node *obj, Node* superklass,
3051                               Node* *failure_control) {
3052   kill_dead_locals();           // Benefit all the uncommon traps
3053   const TypeKlassPtr *tk = _gvn.type(superklass)->is_klassptr();
3054   const Type *toop = TypeOopPtr::make_from_klass(tk->klass());
3055 
3056   // Fast cutout:  Check the case that the cast is vacuously true.
3057   // This detects the common cases where the test will short-circuit
3058   // away completely.  We do this before we perform the null check,
3059   // because if the test is going to turn into zero code, we don't
3060   // want a residual null check left around.  (Causes a slowdown,
3061   // for example, in some objArray manipulations, such as a[i]=a[j].)
3062   if (tk->singleton()) {
3063     const TypeOopPtr* objtp = _gvn.type(obj)->isa_oopptr();
3064     if (objtp != NULL && objtp->klass() != NULL) {
3065       switch (C->static_subtype_check(tk->klass(), objtp->klass())) {
3066       case Compile::SSC_always_true:
3067         // If we know the type check always succeed then we don't use
3068         // the profiling data at this bytecode. Don't lose it, feed it
3069         // to the type system as a speculative type.
3070         return record_profiled_receiver_for_speculation(obj);
3071       case Compile::SSC_always_false:
3072         // It needs a null check because a null will *pass* the cast check.
3073         // A non-null value will always produce an exception.
3074         if (!objtp->maybe_null()) {
3075           builtin_throw(Deoptimization::Reason_class_check, makecon(TypeKlassPtr::make(objtp->klass())));
3076           return top();
3077         } else if (!too_many_traps_or_recompiles(Deoptimization::Reason_null_assert)) {
3078           return null_assert(obj);
3079         }
3080         break; // Fall through to full check
3081       }
3082     }
3083   }
3084 
3085   ciProfileData* data = NULL;
3086   bool safe_for_replace = false;
3087   if (failure_control == NULL) {        // use MDO in regular case only
3088     assert(java_bc() == Bytecodes::_aastore ||
3089            java_bc() == Bytecodes::_checkcast,
3090            "interpreter profiles type checks only for these BCs");
3091     data = method()->method_data()->bci_to_data(bci());
3092     safe_for_replace = true;
3093   }
3094 
3095   // Make the merge point
3096   enum { _obj_path = 1, _null_path, PATH_LIMIT };
3097   RegionNode* region = new RegionNode(PATH_LIMIT);
3098   Node*       phi    = new PhiNode(region, toop);
3099   C->set_has_split_ifs(true); // Has chance for split-if optimization
3100 
3101   // Use null-cast information if it is available
3102   bool speculative_not_null = false;
3103   bool never_see_null = ((failure_control == NULL)  // regular case only
3104                          && seems_never_null(obj, data, speculative_not_null));
3105 
3106   // Null check; get casted pointer; set region slot 3
3107   Node* null_ctl = top();
3108   Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null, safe_for_replace, speculative_not_null);
3109 
3110   // If not_null_obj is dead, only null-path is taken
3111   if (stopped()) {              // Doing instance-of on a NULL?
3112     set_control(null_ctl);
3113     return null();
3114   }
3115   region->init_req(_null_path, null_ctl);
3116   phi   ->init_req(_null_path, null());  // Set null path value
3117   if (null_ctl == top()) {
3118     // Do this eagerly, so that pattern matches like is_diamond_phi
3119     // will work even during parsing.
3120     assert(_null_path == PATH_LIMIT-1, "delete last");
3121     region->del_req(_null_path);
3122     phi   ->del_req(_null_path);
3123   }
3124 
3125   Node* cast_obj = NULL;
3126   if (tk->klass_is_exact()) {
3127     // The following optimization tries to statically cast the speculative type of the object
3128     // (for example obtained during profiling) to the type of the superklass and then do a
3129     // dynamic check that the type of the object is what we expect. To work correctly
3130     // for checkcast and aastore the type of superklass should be exact.
3131     const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
3132     // We may not have profiling here or it may not help us. If we have
3133     // a speculative type use it to perform an exact cast.
3134     ciKlass* spec_obj_type = obj_type->speculative_type();
3135     if (spec_obj_type != NULL || data != NULL) {
3136       cast_obj = maybe_cast_profiled_receiver(not_null_obj, tk->klass(), spec_obj_type, safe_for_replace);
3137       if (cast_obj != NULL) {
3138         if (failure_control != NULL) // failure is now impossible
3139           (*failure_control) = top();
3140         // adjust the type of the phi to the exact klass:
3141         phi->raise_bottom_type(_gvn.type(cast_obj)->meet_speculative(TypePtr::NULL_PTR));
3142       }
3143     }
3144   }
3145 
3146   if (cast_obj == NULL) {
3147     // Load the object's klass
3148     Node* obj_klass = load_object_klass(not_null_obj);
3149 
3150     // Generate the subtype check
3151     Node* not_subtype_ctrl = gen_subtype_check( obj_klass, superklass );
3152 
3153     // Plug in success path into the merge
3154     cast_obj = _gvn.transform(new CheckCastPPNode(control(), not_null_obj, toop));
3155     // Failure path ends in uncommon trap (or may be dead - failure impossible)
3156     if (failure_control == NULL) {
3157       if (not_subtype_ctrl != top()) { // If failure is possible
3158         PreserveJVMState pjvms(this);
3159         set_control(not_subtype_ctrl);
3160         builtin_throw(Deoptimization::Reason_class_check, obj_klass);
3161       }
3162     } else {
3163       (*failure_control) = not_subtype_ctrl;
3164     }
3165   }
3166 
3167   region->init_req(_obj_path, control());
3168   phi   ->init_req(_obj_path, cast_obj);
3169 
3170   // A merge of NULL or Casted-NotNull obj
3171   Node* res = _gvn.transform(phi);
3172 
3173   // Note I do NOT always 'replace_in_map(obj,result)' here.
3174   //  if( tk->klass()->can_be_primary_super()  )
3175     // This means that if I successfully store an Object into an array-of-String
3176     // I 'forget' that the Object is really now known to be a String.  I have to
3177     // do this because we don't have true union types for interfaces - if I store
3178     // a Baz into an array-of-Interface and then tell the optimizer it's an
3179     // Interface, I forget that it's also a Baz and cannot do Baz-like field
3180     // references to it.  FIX THIS WHEN UNION TYPES APPEAR!
3181   //  replace_in_map( obj, res );
3182 
3183   // Return final merged results
3184   set_control( _gvn.transform(region) );
3185   record_for_igvn(region);
3186 
3187   return record_profiled_receiver_for_speculation(res);
3188 }
3189 
3190 //------------------------------next_monitor-----------------------------------
3191 // What number should be given to the next monitor?
3192 int GraphKit::next_monitor() {
3193   int current = jvms()->monitor_depth()* C->sync_stack_slots();
3194   int next = current + C->sync_stack_slots();
3195   // Keep the toplevel high water mark current:
3196   if (C->fixed_slots() < next)  C->set_fixed_slots(next);
3197   return current;
3198 }
3199 
3200 //------------------------------insert_mem_bar---------------------------------
3201 // Memory barrier to avoid floating things around
3202 // The membar serves as a pinch point between both control and all memory slices.
3203 Node* GraphKit::insert_mem_bar(int opcode, Node* precedent) {
3204   MemBarNode* mb = MemBarNode::make(C, opcode, Compile::AliasIdxBot, precedent);
3205   mb->init_req(TypeFunc::Control, control());
3206   mb->init_req(TypeFunc::Memory,  reset_memory());
3207   Node* membar = _gvn.transform(mb);
3208   set_control(_gvn.transform(new ProjNode(membar, TypeFunc::Control)));
3209   set_all_memory_call(membar);
3210   return membar;
3211 }
3212 
3213 //-------------------------insert_mem_bar_volatile----------------------------
3214 // Memory barrier to avoid floating things around
3215 // The membar serves as a pinch point between both control and memory(alias_idx).
3216 // If you want to make a pinch point on all memory slices, do not use this
3217 // function (even with AliasIdxBot); use insert_mem_bar() instead.
3218 Node* GraphKit::insert_mem_bar_volatile(int opcode, int alias_idx, Node* precedent) {
3219   // When Parse::do_put_xxx updates a volatile field, it appends a series
3220   // of MemBarVolatile nodes, one for *each* volatile field alias category.
3221   // The first membar is on the same memory slice as the field store opcode.
3222   // This forces the membar to follow the store.  (Bug 6500685 broke this.)
3223   // All the other membars (for other volatile slices, including AliasIdxBot,
3224   // which stands for all unknown volatile slices) are control-dependent
3225   // on the first membar.  This prevents later volatile loads or stores
3226   // from sliding up past the just-emitted store.
3227 
3228   MemBarNode* mb = MemBarNode::make(C, opcode, alias_idx, precedent);
3229   mb->set_req(TypeFunc::Control,control());
3230   if (alias_idx == Compile::AliasIdxBot) {
3231     mb->set_req(TypeFunc::Memory, merged_memory()->base_memory());
3232   } else {
3233     assert(!(opcode == Op_Initialize && alias_idx != Compile::AliasIdxRaw), "fix caller");
3234     mb->set_req(TypeFunc::Memory, memory(alias_idx));
3235   }
3236   Node* membar = _gvn.transform(mb);
3237   set_control(_gvn.transform(new ProjNode(membar, TypeFunc::Control)));
3238   if (alias_idx == Compile::AliasIdxBot) {
3239     merged_memory()->set_base_memory(_gvn.transform(new ProjNode(membar, TypeFunc::Memory)));
3240   } else {
3241     set_memory(_gvn.transform(new ProjNode(membar, TypeFunc::Memory)),alias_idx);
3242   }
3243   return membar;
3244 }
3245 
3246 //------------------------------shared_lock------------------------------------
3247 // Emit locking code.
3248 FastLockNode* GraphKit::shared_lock(Node* obj) {
3249   // bci is either a monitorenter bc or InvocationEntryBci
3250   // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
3251   assert(SynchronizationEntryBCI == InvocationEntryBci, "");
3252 
3253   if( !GenerateSynchronizationCode )
3254     return NULL;                // Not locking things?
3255   if (stopped())                // Dead monitor?
3256     return NULL;
3257 
3258   assert(dead_locals_are_killed(), "should kill locals before sync. point");
3259 
3260   // Box the stack location
3261   Node* box = _gvn.transform(new BoxLockNode(next_monitor()));
3262   Node* mem = reset_memory();
3263 
3264   FastLockNode * flock = _gvn.transform(new FastLockNode(0, obj, box) )->as_FastLock();
3265   if (UseBiasedLocking && PrintPreciseBiasedLockingStatistics) {
3266     // Create the counters for this fast lock.
3267     flock->create_lock_counter(sync_jvms()); // sync_jvms used to get current bci
3268   }
3269 
3270   // Create the rtm counters for this fast lock if needed.
3271   flock->create_rtm_lock_counter(sync_jvms()); // sync_jvms used to get current bci
3272 
3273   // Add monitor to debug info for the slow path.  If we block inside the
3274   // slow path and de-opt, we need the monitor hanging around
3275   map()->push_monitor( flock );
3276 
3277   const TypeFunc *tf = LockNode::lock_type();
3278   LockNode *lock = new LockNode(C, tf);
3279 
3280   lock->init_req( TypeFunc::Control, control() );
3281   lock->init_req( TypeFunc::Memory , mem );
3282   lock->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
3283   lock->init_req( TypeFunc::FramePtr, frameptr() );
3284   lock->init_req( TypeFunc::ReturnAdr, top() );
3285 
3286   lock->init_req(TypeFunc::Parms + 0, obj);
3287   lock->init_req(TypeFunc::Parms + 1, box);
3288   lock->init_req(TypeFunc::Parms + 2, flock);
3289   add_safepoint_edges(lock);
3290 
3291   lock = _gvn.transform( lock )->as_Lock();
3292 
3293   // lock has no side-effects, sets few values
3294   set_predefined_output_for_runtime_call(lock, mem, TypeRawPtr::BOTTOM);
3295 
3296   insert_mem_bar(Op_MemBarAcquireLock);
3297 
3298   // Add this to the worklist so that the lock can be eliminated
3299   record_for_igvn(lock);
3300 
3301 #ifndef PRODUCT
3302   if (PrintLockStatistics) {
3303     // Update the counter for this lock.  Don't bother using an atomic
3304     // operation since we don't require absolute accuracy.
3305     lock->create_lock_counter(map()->jvms());
3306     increment_counter(lock->counter()->addr());
3307   }
3308 #endif
3309 
3310   return flock;
3311 }
3312 
3313 
3314 //------------------------------shared_unlock----------------------------------
3315 // Emit unlocking code.
3316 void GraphKit::shared_unlock(Node* box, Node* obj) {
3317   // bci is either a monitorenter bc or InvocationEntryBci
3318   // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
3319   assert(SynchronizationEntryBCI == InvocationEntryBci, "");
3320 
3321   if( !GenerateSynchronizationCode )
3322     return;
3323   if (stopped()) {               // Dead monitor?
3324     map()->pop_monitor();        // Kill monitor from debug info
3325     return;
3326   }
3327 
3328   // Memory barrier to avoid floating things down past the locked region
3329   insert_mem_bar(Op_MemBarReleaseLock);
3330 
3331   const TypeFunc *tf = OptoRuntime::complete_monitor_exit_Type();
3332   UnlockNode *unlock = new UnlockNode(C, tf);
3333 #ifdef ASSERT
3334   unlock->set_dbg_jvms(sync_jvms());
3335 #endif
3336   uint raw_idx = Compile::AliasIdxRaw;
3337   unlock->init_req( TypeFunc::Control, control() );
3338   unlock->init_req( TypeFunc::Memory , memory(raw_idx) );
3339   unlock->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
3340   unlock->init_req( TypeFunc::FramePtr, frameptr() );
3341   unlock->init_req( TypeFunc::ReturnAdr, top() );
3342 
3343   unlock->init_req(TypeFunc::Parms + 0, obj);
3344   unlock->init_req(TypeFunc::Parms + 1, box);
3345   unlock = _gvn.transform(unlock)->as_Unlock();
3346 
3347   Node* mem = reset_memory();
3348 
3349   // unlock has no side-effects, sets few values
3350   set_predefined_output_for_runtime_call(unlock, mem, TypeRawPtr::BOTTOM);
3351 
3352   // Kill monitor from debug info
3353   map()->pop_monitor( );
3354 }
3355 
3356 //-------------------------------get_layout_helper-----------------------------
3357 // If the given klass is a constant or known to be an array,
3358 // fetch the constant layout helper value into constant_value
3359 // and return (Node*)NULL.  Otherwise, load the non-constant
3360 // layout helper value, and return the node which represents it.
3361 // This two-faced routine is useful because allocation sites
3362 // almost always feature constant types.
3363 Node* GraphKit::get_layout_helper(Node* klass_node, jint& constant_value) {
3364   const TypeKlassPtr* inst_klass = _gvn.type(klass_node)->isa_klassptr();
3365   if (!StressReflectiveCode && inst_klass != NULL) {
3366     ciKlass* klass = inst_klass->klass();
3367     bool    xklass = inst_klass->klass_is_exact();
3368     if (xklass || klass->is_array_klass()) {
3369       jint lhelper = klass->layout_helper();
3370       if (lhelper != Klass::_lh_neutral_value) {
3371         constant_value = lhelper;
3372         return (Node*) NULL;
3373       }
3374     }
3375   }
3376   constant_value = Klass::_lh_neutral_value;  // put in a known value
3377   Node* lhp = basic_plus_adr(klass_node, klass_node, in_bytes(Klass::layout_helper_offset()));
3378   return make_load(NULL, lhp, TypeInt::INT, T_INT, MemNode::unordered);
3379 }
3380 
3381 // We just put in an allocate/initialize with a big raw-memory effect.
3382 // Hook selected additional alias categories on the initialization.
3383 static void hook_memory_on_init(GraphKit& kit, int alias_idx,
3384                                 MergeMemNode* init_in_merge,
3385                                 Node* init_out_raw) {
3386   DEBUG_ONLY(Node* init_in_raw = init_in_merge->base_memory());
3387   assert(init_in_merge->memory_at(alias_idx) == init_in_raw, "");
3388 
3389   Node* prevmem = kit.memory(alias_idx);
3390   init_in_merge->set_memory_at(alias_idx, prevmem);
3391   kit.set_memory(init_out_raw, alias_idx);
3392 }
3393 
3394 //---------------------------set_output_for_allocation-------------------------
3395 Node* GraphKit::set_output_for_allocation(AllocateNode* alloc,
3396                                           const TypeOopPtr* oop_type,
3397                                           bool deoptimize_on_exception) {
3398   int rawidx = Compile::AliasIdxRaw;
3399   alloc->set_req( TypeFunc::FramePtr, frameptr() );
3400   add_safepoint_edges(alloc);
3401   Node* allocx = _gvn.transform(alloc);
3402   set_control( _gvn.transform(new ProjNode(allocx, TypeFunc::Control) ) );
3403   // create memory projection for i_o
3404   set_memory ( _gvn.transform( new ProjNode(allocx, TypeFunc::Memory, true) ), rawidx );
3405   make_slow_call_ex(allocx, env()->Throwable_klass(), true, deoptimize_on_exception);
3406 
3407   // create a memory projection as for the normal control path
3408   Node* malloc = _gvn.transform(new ProjNode(allocx, TypeFunc::Memory));
3409   set_memory(malloc, rawidx);
3410 
3411   // a normal slow-call doesn't change i_o, but an allocation does
3412   // we create a separate i_o projection for the normal control path
3413   set_i_o(_gvn.transform( new ProjNode(allocx, TypeFunc::I_O, false) ) );
3414   Node* rawoop = _gvn.transform( new ProjNode(allocx, TypeFunc::Parms) );
3415 
3416   // put in an initialization barrier
3417   InitializeNode* init = insert_mem_bar_volatile(Op_Initialize, rawidx,
3418                                                  rawoop)->as_Initialize();
3419   assert(alloc->initialization() == init,  "2-way macro link must work");
3420   assert(init ->allocation()     == alloc, "2-way macro link must work");
3421   {
3422     // Extract memory strands which may participate in the new object's
3423     // initialization, and source them from the new InitializeNode.
3424     // This will allow us to observe initializations when they occur,
3425     // and link them properly (as a group) to the InitializeNode.
3426     assert(init->in(InitializeNode::Memory) == malloc, "");
3427     MergeMemNode* minit_in = MergeMemNode::make(malloc);
3428     init->set_req(InitializeNode::Memory, minit_in);
3429     record_for_igvn(minit_in); // fold it up later, if possible
3430     Node* minit_out = memory(rawidx);
3431     assert(minit_out->is_Proj() && minit_out->in(0) == init, "");
3432     // Add an edge in the MergeMem for the header fields so an access
3433     // to one of those has correct memory state
3434     set_memory(minit_out, C->get_alias_index(oop_type->add_offset(oopDesc::mark_offset_in_bytes())));
3435     set_memory(minit_out, C->get_alias_index(oop_type->add_offset(oopDesc::klass_offset_in_bytes())));
3436     if (oop_type->isa_aryptr()) {
3437       const TypePtr* telemref = oop_type->add_offset(Type::OffsetBot);
3438       int            elemidx  = C->get_alias_index(telemref);
3439       hook_memory_on_init(*this, elemidx, minit_in, minit_out);
3440     } else if (oop_type->isa_instptr()) {
3441       ciInstanceKlass* ik = oop_type->klass()->as_instance_klass();
3442       for (int i = 0, len = ik->nof_nonstatic_fields(); i < len; i++) {
3443         ciField* field = ik->nonstatic_field_at(i);
3444         if (field->offset() >= TrackedInitializationLimit * HeapWordSize)
3445           continue;  // do not bother to track really large numbers of fields
3446         // Find (or create) the alias category for this field:
3447         int fieldidx = C->alias_type(field)->index();
3448         hook_memory_on_init(*this, fieldidx, minit_in, minit_out);
3449       }
3450     }
3451   }
3452 
3453   // Cast raw oop to the real thing...
3454   Node* javaoop = new CheckCastPPNode(control(), rawoop, oop_type);
3455   javaoop = _gvn.transform(javaoop);
3456   C->set_recent_alloc(control(), javaoop);
3457   assert(just_allocated_object(control()) == javaoop, "just allocated");
3458 
3459 #ifdef ASSERT
3460   { // Verify that the AllocateNode::Ideal_allocation recognizers work:
3461     assert(AllocateNode::Ideal_allocation(rawoop, &_gvn) == alloc,
3462            "Ideal_allocation works");
3463     assert(AllocateNode::Ideal_allocation(javaoop, &_gvn) == alloc,
3464            "Ideal_allocation works");
3465     if (alloc->is_AllocateArray()) {
3466       assert(AllocateArrayNode::Ideal_array_allocation(rawoop, &_gvn) == alloc->as_AllocateArray(),
3467              "Ideal_allocation works");
3468       assert(AllocateArrayNode::Ideal_array_allocation(javaoop, &_gvn) == alloc->as_AllocateArray(),
3469              "Ideal_allocation works");
3470     } else {
3471       assert(alloc->in(AllocateNode::ALength)->is_top(), "no length, please");
3472     }
3473   }
3474 #endif //ASSERT
3475 
3476   return javaoop;
3477 }
3478 
3479 //---------------------------new_instance--------------------------------------
3480 // This routine takes a klass_node which may be constant (for a static type)
3481 // or may be non-constant (for reflective code).  It will work equally well
3482 // for either, and the graph will fold nicely if the optimizer later reduces
3483 // the type to a constant.
3484 // The optional arguments are for specialized use by intrinsics:
3485 //  - If 'extra_slow_test' if not null is an extra condition for the slow-path.
3486 //  - If 'return_size_val', report the the total object size to the caller.
3487 //  - deoptimize_on_exception controls how Java exceptions are handled (rethrow vs deoptimize)
3488 Node* GraphKit::new_instance(Node* klass_node,
3489                              Node* extra_slow_test,
3490                              Node* *return_size_val,
3491                              bool deoptimize_on_exception) {
3492   // Compute size in doublewords
3493   // The size is always an integral number of doublewords, represented
3494   // as a positive bytewise size stored in the klass's layout_helper.
3495   // The layout_helper also encodes (in a low bit) the need for a slow path.
3496   jint  layout_con = Klass::_lh_neutral_value;
3497   Node* layout_val = get_layout_helper(klass_node, layout_con);
3498   int   layout_is_con = (layout_val == NULL);
3499 
3500   if (extra_slow_test == NULL)  extra_slow_test = intcon(0);
3501   // Generate the initial go-slow test.  It's either ALWAYS (return a
3502   // Node for 1) or NEVER (return a NULL) or perhaps (in the reflective
3503   // case) a computed value derived from the layout_helper.
3504   Node* initial_slow_test = NULL;
3505   if (layout_is_con) {
3506     assert(!StressReflectiveCode, "stress mode does not use these paths");
3507     bool must_go_slow = Klass::layout_helper_needs_slow_path(layout_con);
3508     initial_slow_test = must_go_slow ? intcon(1) : extra_slow_test;
3509   } else {   // reflective case
3510     // This reflective path is used by Unsafe.allocateInstance.
3511     // (It may be stress-tested by specifying StressReflectiveCode.)
3512     // Basically, we want to get into the VM is there's an illegal argument.
3513     Node* bit = intcon(Klass::_lh_instance_slow_path_bit);
3514     initial_slow_test = _gvn.transform( new AndINode(layout_val, bit) );
3515     if (extra_slow_test != intcon(0)) {
3516       initial_slow_test = _gvn.transform( new OrINode(initial_slow_test, extra_slow_test) );
3517     }
3518     // (Macro-expander will further convert this to a Bool, if necessary.)
3519   }
3520 
3521   // Find the size in bytes.  This is easy; it's the layout_helper.
3522   // The size value must be valid even if the slow path is taken.
3523   Node* size = NULL;
3524   if (layout_is_con) {
3525     size = MakeConX(Klass::layout_helper_size_in_bytes(layout_con));
3526   } else {   // reflective case
3527     // This reflective path is used by clone and Unsafe.allocateInstance.
3528     size = ConvI2X(layout_val);
3529 
3530     // Clear the low bits to extract layout_helper_size_in_bytes:
3531     assert((int)Klass::_lh_instance_slow_path_bit < BytesPerLong, "clear bit");
3532     Node* mask = MakeConX(~ (intptr_t)right_n_bits(LogBytesPerLong));
3533     size = _gvn.transform( new AndXNode(size, mask) );
3534   }
3535   if (return_size_val != NULL) {
3536     (*return_size_val) = size;
3537   }
3538 
3539   // This is a precise notnull oop of the klass.
3540   // (Actually, it need not be precise if this is a reflective allocation.)
3541   // It's what we cast the result to.
3542   const TypeKlassPtr* tklass = _gvn.type(klass_node)->isa_klassptr();
3543   if (!tklass)  tklass = TypeKlassPtr::OBJECT;
3544   const TypeOopPtr* oop_type = tklass->as_instance_type();
3545 
3546   // Now generate allocation code
3547 
3548   // The entire memory state is needed for slow path of the allocation
3549   // since GC and deoptimization can happened.
3550   Node *mem = reset_memory();
3551   set_all_memory(mem); // Create new memory state
3552 
3553   AllocateNode* alloc = new AllocateNode(C, AllocateNode::alloc_type(Type::TOP),
3554                                          control(), mem, i_o(),
3555                                          size, klass_node,
3556                                          initial_slow_test);
3557 
3558   return set_output_for_allocation(alloc, oop_type, deoptimize_on_exception);
3559 }
3560 
3561 //-------------------------------new_array-------------------------------------
3562 // helper for both newarray and anewarray
3563 // The 'length' parameter is (obviously) the length of the array.
3564 // See comments on new_instance for the meaning of the other arguments.
3565 Node* GraphKit::new_array(Node* klass_node,     // array klass (maybe variable)
3566                           Node* length,         // number of array elements
3567                           int   nargs,          // number of arguments to push back for uncommon trap
3568                           Node* *return_size_val,
3569                           bool deoptimize_on_exception) {
3570   jint  layout_con = Klass::_lh_neutral_value;
3571   Node* layout_val = get_layout_helper(klass_node, layout_con);
3572   int   layout_is_con = (layout_val == NULL);
3573 
3574   if (!layout_is_con && !StressReflectiveCode &&
3575       !too_many_traps(Deoptimization::Reason_class_check)) {
3576     // This is a reflective array creation site.
3577     // Optimistically assume that it is a subtype of Object[],
3578     // so that we can fold up all the address arithmetic.
3579     layout_con = Klass::array_layout_helper(T_OBJECT);
3580     Node* cmp_lh = _gvn.transform( new CmpINode(layout_val, intcon(layout_con)) );
3581     Node* bol_lh = _gvn.transform( new BoolNode(cmp_lh, BoolTest::eq) );
3582     { BuildCutout unless(this, bol_lh, PROB_MAX);
3583       inc_sp(nargs);
3584       uncommon_trap(Deoptimization::Reason_class_check,
3585                     Deoptimization::Action_maybe_recompile);
3586     }
3587     layout_val = NULL;
3588     layout_is_con = true;
3589   }
3590 
3591   // Generate the initial go-slow test.  Make sure we do not overflow
3592   // if length is huge (near 2Gig) or negative!  We do not need
3593   // exact double-words here, just a close approximation of needed
3594   // double-words.  We can't add any offset or rounding bits, lest we
3595   // take a size -1 of bytes and make it positive.  Use an unsigned
3596   // compare, so negative sizes look hugely positive.
3597   int fast_size_limit = FastAllocateSizeLimit;
3598   if (layout_is_con) {
3599     assert(!StressReflectiveCode, "stress mode does not use these paths");
3600     // Increase the size limit if we have exact knowledge of array type.
3601     int log2_esize = Klass::layout_helper_log2_element_size(layout_con);
3602     fast_size_limit <<= (LogBytesPerLong - log2_esize);
3603   }
3604 
3605   Node* initial_slow_cmp  = _gvn.transform( new CmpUNode( length, intcon( fast_size_limit ) ) );
3606   Node* initial_slow_test = _gvn.transform( new BoolNode( initial_slow_cmp, BoolTest::gt ) );
3607 
3608   // --- Size Computation ---
3609   // array_size = round_to_heap(array_header + (length << elem_shift));
3610   // where round_to_heap(x) == align_to(x, MinObjAlignmentInBytes)
3611   // and align_to(x, y) == ((x + y-1) & ~(y-1))
3612   // The rounding mask is strength-reduced, if possible.
3613   int round_mask = MinObjAlignmentInBytes - 1;
3614   Node* header_size = NULL;
3615   int   header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
3616   // (T_BYTE has the weakest alignment and size restrictions...)
3617   if (layout_is_con) {
3618     int       hsize  = Klass::layout_helper_header_size(layout_con);
3619     int       eshift = Klass::layout_helper_log2_element_size(layout_con);
3620     BasicType etype  = Klass::layout_helper_element_type(layout_con);
3621     if ((round_mask & ~right_n_bits(eshift)) == 0)
3622       round_mask = 0;  // strength-reduce it if it goes away completely
3623     assert((hsize & right_n_bits(eshift)) == 0, "hsize is pre-rounded");
3624     assert(header_size_min <= hsize, "generic minimum is smallest");
3625     header_size_min = hsize;
3626     header_size = intcon(hsize + round_mask);
3627   } else {
3628     Node* hss   = intcon(Klass::_lh_header_size_shift);
3629     Node* hsm   = intcon(Klass::_lh_header_size_mask);
3630     Node* hsize = _gvn.transform( new URShiftINode(layout_val, hss) );
3631     hsize       = _gvn.transform( new AndINode(hsize, hsm) );
3632     Node* mask  = intcon(round_mask);
3633     header_size = _gvn.transform( new AddINode(hsize, mask) );
3634   }
3635 
3636   Node* elem_shift = NULL;
3637   if (layout_is_con) {
3638     int eshift = Klass::layout_helper_log2_element_size(layout_con);
3639     if (eshift != 0)
3640       elem_shift = intcon(eshift);
3641   } else {
3642     // There is no need to mask or shift this value.
3643     // The semantics of LShiftINode include an implicit mask to 0x1F.
3644     assert(Klass::_lh_log2_element_size_shift == 0, "use shift in place");
3645     elem_shift = layout_val;
3646   }
3647 
3648   // Transition to native address size for all offset calculations:
3649   Node* lengthx = ConvI2X(length);
3650   Node* headerx = ConvI2X(header_size);
3651 #ifdef _LP64
3652   { const TypeInt* tilen = _gvn.find_int_type(length);
3653     if (tilen != NULL && tilen->_lo < 0) {
3654       // Add a manual constraint to a positive range.  Cf. array_element_address.
3655       jint size_max = fast_size_limit;
3656       if (size_max > tilen->_hi)  size_max = tilen->_hi;
3657       const TypeInt* tlcon = TypeInt::make(0, size_max, Type::WidenMin);
3658 
3659       // Only do a narrow I2L conversion if the range check passed.
3660       IfNode* iff = new IfNode(control(), initial_slow_test, PROB_MIN, COUNT_UNKNOWN);
3661       _gvn.transform(iff);
3662       RegionNode* region = new RegionNode(3);
3663       _gvn.set_type(region, Type::CONTROL);
3664       lengthx = new PhiNode(region, TypeLong::LONG);
3665       _gvn.set_type(lengthx, TypeLong::LONG);
3666 
3667       // Range check passed. Use ConvI2L node with narrow type.
3668       Node* passed = IfFalse(iff);
3669       region->init_req(1, passed);
3670       // Make I2L conversion control dependent to prevent it from
3671       // floating above the range check during loop optimizations.
3672       lengthx->init_req(1, C->constrained_convI2L(&_gvn, length, tlcon, passed));
3673 
3674       // Range check failed. Use ConvI2L with wide type because length may be invalid.
3675       region->init_req(2, IfTrue(iff));
3676       lengthx->init_req(2, ConvI2X(length));
3677 
3678       set_control(region);
3679       record_for_igvn(region);
3680       record_for_igvn(lengthx);
3681     }
3682   }
3683 #endif
3684 
3685   // Combine header size (plus rounding) and body size.  Then round down.
3686   // This computation cannot overflow, because it is used only in two
3687   // places, one where the length is sharply limited, and the other
3688   // after a successful allocation.
3689   Node* abody = lengthx;
3690   if (elem_shift != NULL)
3691     abody     = _gvn.transform( new LShiftXNode(lengthx, elem_shift) );
3692   Node* size  = _gvn.transform( new AddXNode(headerx, abody) );
3693   if (round_mask != 0) {
3694     Node* mask = MakeConX(~round_mask);
3695     size       = _gvn.transform( new AndXNode(size, mask) );
3696   }
3697   // else if round_mask == 0, the size computation is self-rounding
3698 
3699   if (return_size_val != NULL) {
3700     // This is the size
3701     (*return_size_val) = size;
3702   }
3703 
3704   // Now generate allocation code
3705 
3706   // The entire memory state is needed for slow path of the allocation
3707   // since GC and deoptimization can happened.
3708   Node *mem = reset_memory();
3709   set_all_memory(mem); // Create new memory state
3710 
3711   if (initial_slow_test->is_Bool()) {
3712     // Hide it behind a CMoveI, or else PhaseIdealLoop::split_up will get sick.
3713     initial_slow_test = initial_slow_test->as_Bool()->as_int_value(&_gvn);
3714   }
3715 
3716   // Create the AllocateArrayNode and its result projections
3717   AllocateArrayNode* alloc
3718     = new AllocateArrayNode(C, AllocateArrayNode::alloc_type(TypeInt::INT),
3719                             control(), mem, i_o(),
3720                             size, klass_node,
3721                             initial_slow_test,
3722                             length);
3723 
3724   // Cast to correct type.  Note that the klass_node may be constant or not,
3725   // and in the latter case the actual array type will be inexact also.
3726   // (This happens via a non-constant argument to inline_native_newArray.)
3727   // In any case, the value of klass_node provides the desired array type.
3728   const TypeInt* length_type = _gvn.find_int_type(length);
3729   const TypeOopPtr* ary_type = _gvn.type(klass_node)->is_klassptr()->as_instance_type();
3730   if (ary_type->isa_aryptr() && length_type != NULL) {
3731     // Try to get a better type than POS for the size
3732     ary_type = ary_type->is_aryptr()->cast_to_size(length_type);
3733   }
3734 
3735   Node* javaoop = set_output_for_allocation(alloc, ary_type, deoptimize_on_exception);
3736 
3737   // Cast length on remaining path to be as narrow as possible
3738   if (map()->find_edge(length) >= 0) {
3739     Node* ccast = alloc->make_ideal_length(ary_type, &_gvn);
3740     if (ccast != length) {
3741       _gvn.set_type_bottom(ccast);
3742       record_for_igvn(ccast);
3743       replace_in_map(length, ccast);
3744     }
3745   }
3746 
3747   return javaoop;
3748 }
3749 
3750 // The following "Ideal_foo" functions are placed here because they recognize
3751 // the graph shapes created by the functions immediately above.
3752 
3753 //---------------------------Ideal_allocation----------------------------------
3754 // Given an oop pointer or raw pointer, see if it feeds from an AllocateNode.
3755 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase) {
3756   if (ptr == NULL) {     // reduce dumb test in callers
3757     return NULL;
3758   }
3759 
3760 #if INCLUDE_SHENANDOAHGC
3761   if (UseShenandoahGC) {
3762     BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
3763     ptr = bs->step_over_gc_barrier(ptr);
3764   }
3765 #endif
3766 
3767   if (ptr->is_CheckCastPP()) { // strip only one raw-to-oop cast
3768     ptr = ptr->in(1);
3769     if (ptr == NULL) return NULL;
3770   }
3771   // Return NULL for allocations with several casts:
3772   //   j.l.reflect.Array.newInstance(jobject, jint)
3773   //   Object.clone()
3774   // to keep more precise type from last cast.
3775   if (ptr->is_Proj()) {
3776     Node* allo = ptr->in(0);
3777     if (allo != NULL && allo->is_Allocate()) {
3778       return allo->as_Allocate();
3779     }
3780   }
3781   // Report failure to match.
3782   return NULL;
3783 }
3784 
3785 // Fancy version which also strips off an offset (and reports it to caller).
3786 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase,
3787                                              intptr_t& offset) {
3788   Node* base = AddPNode::Ideal_base_and_offset(ptr, phase, offset);
3789   if (base == NULL)  return NULL;
3790   return Ideal_allocation(base, phase);
3791 }
3792 
3793 // Trace Initialize <- Proj[Parm] <- Allocate
3794 AllocateNode* InitializeNode::allocation() {
3795   Node* rawoop = in(InitializeNode::RawAddress);
3796   if (rawoop->is_Proj()) {
3797     Node* alloc = rawoop->in(0);
3798     if (alloc->is_Allocate()) {
3799       return alloc->as_Allocate();
3800     }
3801   }
3802   return NULL;
3803 }
3804 
3805 // Trace Allocate -> Proj[Parm] -> Initialize
3806 InitializeNode* AllocateNode::initialization() {
3807   ProjNode* rawoop = proj_out_or_null(AllocateNode::RawAddress);
3808   if (rawoop == NULL)  return NULL;
3809   for (DUIterator_Fast imax, i = rawoop->fast_outs(imax); i < imax; i++) {
3810     Node* init = rawoop->fast_out(i);
3811     if (init->is_Initialize()) {
3812       assert(init->as_Initialize()->allocation() == this, "2-way link");
3813       return init->as_Initialize();
3814     }
3815   }
3816   return NULL;
3817 }
3818 
3819 //----------------------------- loop predicates ---------------------------
3820 
3821 //------------------------------add_predicate_impl----------------------------
3822 void GraphKit::add_empty_predicate_impl(Deoptimization::DeoptReason reason, int nargs) {
3823   // Too many traps seen?
3824   if (too_many_traps(reason)) {
3825 #ifdef ASSERT
3826     if (TraceLoopPredicate) {
3827       int tc = C->trap_count(reason);
3828       tty->print("too many traps=%s tcount=%d in ",
3829                     Deoptimization::trap_reason_name(reason), tc);
3830       method()->print(); // which method has too many predicate traps
3831       tty->cr();
3832     }
3833 #endif
3834     // We cannot afford to take more traps here,
3835     // do not generate predicate.
3836     return;
3837   }
3838 
3839   Node *cont    = _gvn.intcon(1);
3840   Node* opq     = _gvn.transform(new Opaque1Node(C, cont));
3841   Node *bol     = _gvn.transform(new Conv2BNode(opq));
3842   IfNode* iff   = create_and_map_if(control(), bol, PROB_MAX, COUNT_UNKNOWN);
3843   Node* iffalse = _gvn.transform(new IfFalseNode(iff));
3844   C->add_predicate_opaq(opq);
3845   {
3846     PreserveJVMState pjvms(this);
3847     set_control(iffalse);
3848     inc_sp(nargs);
3849     uncommon_trap(reason, Deoptimization::Action_maybe_recompile);
3850   }
3851   Node* iftrue = _gvn.transform(new IfTrueNode(iff));
3852   set_control(iftrue);
3853 }
3854 
3855 //------------------------------add_predicate---------------------------------
3856 void GraphKit::add_empty_predicates(int nargs) {
3857   // These loop predicates remain empty. All concrete loop predicates are inserted above the corresponding
3858   // empty loop predicate later by 'PhaseIdealLoop::create_new_if_for_predicate'. All concrete loop predicates of
3859   // a specific kind (normal, profile or limit check) share the same uncommon trap as the empty loop predicate.
3860   if (UseLoopPredicate) {
3861     add_empty_predicate_impl(Deoptimization::Reason_predicate, nargs);
3862   }
3863   if (UseProfiledLoopPredicate) {
3864     add_empty_predicate_impl(Deoptimization::Reason_profile_predicate, nargs);
3865   }
3866   // loop's limit check predicate should be near the loop.
3867   add_empty_predicate_impl(Deoptimization::Reason_loop_limit_check, nargs);
3868 }
3869 
3870 void GraphKit::sync_kit(IdealKit& ideal) {
3871   set_all_memory(ideal.merged_memory());
3872   set_i_o(ideal.i_o());
3873   set_control(ideal.ctrl());
3874 }
3875 
3876 void GraphKit::final_sync(IdealKit& ideal) {
3877   // Final sync IdealKit and graphKit.
3878   sync_kit(ideal);
3879 }
3880 
3881 Node* GraphKit::load_String_length(Node* ctrl, Node* str) {
3882   Node* len = load_array_length(load_String_value(ctrl, str));
3883   Node* coder = load_String_coder(ctrl, str);
3884   // Divide length by 2 if coder is UTF16
3885   return _gvn.transform(new RShiftINode(len, coder));
3886 }
3887 
3888 Node* GraphKit::load_String_value(Node* ctrl, Node* str) {
3889   int value_offset = java_lang_String::value_offset_in_bytes();
3890   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
3891                                                      false, NULL, 0);
3892   const TypePtr* value_field_type = string_type->add_offset(value_offset);
3893   const TypeAryPtr* value_type = TypeAryPtr::make(TypePtr::NotNull,
3894                                                   TypeAry::make(TypeInt::BYTE, TypeInt::POS),
3895                                                   ciTypeArrayKlass::make(T_BYTE), true, 0);
3896   Node* p = basic_plus_adr(str, str, value_offset);
3897   Node* load = access_load_at(str, p, value_field_type, value_type, T_OBJECT,
3898                               IN_HEAP | C2_CONTROL_DEPENDENT_LOAD);
3899   // String.value field is known to be @Stable.
3900   if (UseImplicitStableValues) {
3901     load = cast_array_to_stable(load, value_type);
3902   }
3903   return load;
3904 }
3905 
3906 Node* GraphKit::load_String_coder(Node* ctrl, Node* str) {
3907   if (!CompactStrings) {
3908     return intcon(java_lang_String::CODER_UTF16);
3909   }
3910   int coder_offset = java_lang_String::coder_offset_in_bytes();
3911   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
3912                                                      false, NULL, 0);
3913   const TypePtr* coder_field_type = string_type->add_offset(coder_offset);
3914   int coder_field_idx = C->get_alias_index(coder_field_type);
3915   return make_load(ctrl, basic_plus_adr(str, str, coder_offset),
3916                    TypeInt::BYTE, T_BYTE, coder_field_idx, MemNode::unordered);
3917 }
3918 
3919 void GraphKit::store_String_value(Node* ctrl, Node* str, Node* value) {
3920   int value_offset = java_lang_String::value_offset_in_bytes();
3921   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
3922                                                      false, NULL, 0);
3923   const TypePtr* value_field_type = string_type->add_offset(value_offset);
3924   access_store_at(ctrl, str,  basic_plus_adr(str, value_offset), value_field_type,
3925                   value, TypeAryPtr::BYTES, T_OBJECT, IN_HEAP);
3926 }
3927 
3928 void GraphKit::store_String_coder(Node* ctrl, Node* str, Node* value) {
3929   int coder_offset = java_lang_String::coder_offset_in_bytes();
3930   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
3931                                                      false, NULL, 0);
3932   const TypePtr* coder_field_type = string_type->add_offset(coder_offset);
3933   int coder_field_idx = C->get_alias_index(coder_field_type);
3934   store_to_memory(ctrl, basic_plus_adr(str, coder_offset),
3935                   value, T_BYTE, coder_field_idx, MemNode::unordered);
3936 }
3937 
3938 // Capture src and dst memory state with a MergeMemNode
3939 Node* GraphKit::capture_memory(const TypePtr* src_type, const TypePtr* dst_type) {
3940   if (src_type == dst_type) {
3941     // Types are equal, we don't need a MergeMemNode
3942     return memory(src_type);
3943   }
3944   MergeMemNode* merge = MergeMemNode::make(map()->memory());
3945   record_for_igvn(merge); // fold it up later, if possible
3946   int src_idx = C->get_alias_index(src_type);
3947   int dst_idx = C->get_alias_index(dst_type);
3948   merge->set_memory_at(src_idx, memory(src_idx));
3949   merge->set_memory_at(dst_idx, memory(dst_idx));
3950   return merge;
3951 }
3952 
3953 Node* GraphKit::compress_string(Node* src, const TypeAryPtr* src_type, Node* dst, Node* count) {
3954   assert(Matcher::match_rule_supported(Op_StrCompressedCopy), "Intrinsic not supported");
3955   assert(src_type == TypeAryPtr::BYTES || src_type == TypeAryPtr::CHARS, "invalid source type");
3956   // If input and output memory types differ, capture both states to preserve
3957   // the dependency between preceding and subsequent loads/stores.
3958   // For example, the following program:
3959   //  StoreB
3960   //  compress_string
3961   //  LoadB
3962   // has this memory graph (use->def):
3963   //  LoadB -> compress_string -> CharMem
3964   //             ... -> StoreB -> ByteMem
3965   // The intrinsic hides the dependency between LoadB and StoreB, causing
3966   // the load to read from memory not containing the result of the StoreB.
3967   // The correct memory graph should look like this:
3968   //  LoadB -> compress_string -> MergeMem(CharMem, StoreB(ByteMem))
3969   Node* mem = capture_memory(src_type, TypeAryPtr::BYTES);
3970   StrCompressedCopyNode* str = new StrCompressedCopyNode(control(), mem, src, dst, count);
3971   Node* res_mem = _gvn.transform(new SCMemProjNode(str));
3972   set_memory(res_mem, TypeAryPtr::BYTES);
3973   return str;
3974 }
3975 
3976 void GraphKit::inflate_string(Node* src, Node* dst, const TypeAryPtr* dst_type, Node* count) {
3977   assert(Matcher::match_rule_supported(Op_StrInflatedCopy), "Intrinsic not supported");
3978   assert(dst_type == TypeAryPtr::BYTES || dst_type == TypeAryPtr::CHARS, "invalid dest type");
3979   // Capture src and dst memory (see comment in 'compress_string').
3980   Node* mem = capture_memory(TypeAryPtr::BYTES, dst_type);
3981   StrInflatedCopyNode* str = new StrInflatedCopyNode(control(), mem, src, dst, count);
3982   set_memory(_gvn.transform(str), dst_type);
3983 }
3984 
3985 void GraphKit::inflate_string_slow(Node* src, Node* dst, Node* start, Node* count) {
3986   /**
3987    * int i_char = start;
3988    * for (int i_byte = 0; i_byte < count; i_byte++) {
3989    *   dst[i_char++] = (char)(src[i_byte] & 0xff);
3990    * }
3991    */
3992   add_empty_predicates();
3993   RegionNode* head = new RegionNode(3);
3994   head->init_req(1, control());
3995   gvn().set_type(head, Type::CONTROL);
3996   record_for_igvn(head);
3997 
3998   Node* i_byte = new PhiNode(head, TypeInt::INT);
3999   i_byte->init_req(1, intcon(0));
4000   gvn().set_type(i_byte, TypeInt::INT);
4001   record_for_igvn(i_byte);
4002 
4003   Node* i_char = new PhiNode(head, TypeInt::INT);
4004   i_char->init_req(1, start);
4005   gvn().set_type(i_char, TypeInt::INT);
4006   record_for_igvn(i_char);
4007 
4008   Node* mem = PhiNode::make(head, memory(TypeAryPtr::BYTES), Type::MEMORY, TypeAryPtr::BYTES);
4009   gvn().set_type(mem, Type::MEMORY);
4010   record_for_igvn(mem);
4011   set_control(head);
4012   set_memory(mem, TypeAryPtr::BYTES);
4013   Node* ch = load_array_element(control(), src, i_byte, TypeAryPtr::BYTES);
4014   Node* st = store_to_memory(control(), array_element_address(dst, i_char, T_BYTE),
4015                              AndI(ch, intcon(0xff)), T_CHAR, TypeAryPtr::BYTES, MemNode::unordered,
4016                              false, false, true /* mismatched */);
4017 
4018   IfNode* iff = create_and_map_if(head, Bool(CmpI(i_byte, count), BoolTest::lt), PROB_FAIR, COUNT_UNKNOWN);
4019   head->init_req(2, IfTrue(iff));
4020   mem->init_req(2, st);
4021   i_byte->init_req(2, AddI(i_byte, intcon(1)));
4022   i_char->init_req(2, AddI(i_char, intcon(2)));
4023 
4024   set_control(IfFalse(iff));
4025   set_memory(st, TypeAryPtr::BYTES);
4026 }
4027 
4028 Node* GraphKit::make_constant_from_field(ciField* field, Node* obj) {
4029   if (!field->is_constant()) {
4030     return NULL; // Field not marked as constant.
4031   }
4032   ciInstance* holder = NULL;
4033   if (!field->is_static()) {
4034     ciObject* const_oop = obj->bottom_type()->is_oopptr()->const_oop();
4035     if (const_oop != NULL && const_oop->is_instance()) {
4036       holder = const_oop->as_instance();
4037     }
4038   }
4039   const Type* con_type = Type::make_constant_from_field(field, holder, field->layout_type(),
4040                                                         /*is_unsigned_load=*/false);
4041   if (con_type != NULL) {
4042     return makecon(con_type);
4043   }
4044   return NULL;
4045 }
4046 
4047 Node* GraphKit::cast_array_to_stable(Node* ary, const TypeAryPtr* ary_type) {
4048   // Reify the property as a CastPP node in Ideal graph to comply with monotonicity
4049   // assumption of CCP analysis.
4050   return _gvn.transform(new CastPPNode(ary, ary_type->cast_to_stable(true)));
4051 }