1 /*
   2  * Copyright (c) 2001, 2016, 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 "compiler/compileLog.hpp"
  27 #include "ci/ciValueKlass.hpp"
  28 #include "gc/g1/g1SATBCardTableModRefBS.hpp"
  29 #include "gc/g1/heapRegion.hpp"
  30 #include "gc/shared/barrierSet.hpp"
  31 #include "gc/shared/cardTableModRefBS.hpp"
  32 #include "gc/shared/collectedHeap.hpp"
  33 #include "memory/resourceArea.hpp"
  34 #include "opto/addnode.hpp"
  35 #include "opto/castnode.hpp"
  36 #include "opto/convertnode.hpp"
  37 #include "opto/graphKit.hpp"
  38 #include "opto/idealKit.hpp"
  39 #include "opto/intrinsicnode.hpp"
  40 #include "opto/locknode.hpp"
  41 #include "opto/machnode.hpp"
  42 #include "opto/opaquenode.hpp"
  43 #include "opto/parse.hpp"
  44 #include "opto/rootnode.hpp"
  45 #include "opto/runtime.hpp"
  46 #include "opto/valuetypenode.hpp"
  47 #include "runtime/deoptimization.hpp"
  48 #include "runtime/sharedRuntime.hpp"
  49 
  50 //----------------------------GraphKit-----------------------------------------
  51 // Main utility constructor.
  52 GraphKit::GraphKit(JVMState* jvms)
  53   : Phase(Phase::Parser),
  54     _env(C->env()),
  55     _gvn(*C->initial_gvn())
  56 {
  57   _exceptions = jvms->map()->next_exception();
  58   if (_exceptions != NULL)  jvms->map()->set_next_exception(NULL);
  59   set_jvms(jvms);
  60 }
  61 
  62 // Private constructor for parser.
  63 GraphKit::GraphKit()
  64   : Phase(Phase::Parser),
  65     _env(C->env()),
  66     _gvn(*C->initial_gvn())
  67 {
  68   _exceptions = NULL;
  69   set_map(NULL);
  70   debug_only(_sp = -99);
  71   debug_only(set_bci(-99));
  72 }
  73 
  74 
  75 
  76 //---------------------------clean_stack---------------------------------------
  77 // Clear away rubbish from the stack area of the JVM state.
  78 // This destroys any arguments that may be waiting on the stack.
  79 void GraphKit::clean_stack(int from_sp) {
  80   SafePointNode* map      = this->map();
  81   JVMState*      jvms     = this->jvms();
  82   int            stk_size = jvms->stk_size();
  83   int            stkoff   = jvms->stkoff();
  84   Node*          top      = this->top();
  85   for (int i = from_sp; i < stk_size; i++) {
  86     if (map->in(stkoff + i) != top) {
  87       map->set_req(stkoff + i, top);
  88     }
  89   }
  90 }
  91 
  92 
  93 //--------------------------------sync_jvms-----------------------------------
  94 // Make sure our current jvms agrees with our parse state.
  95 JVMState* GraphKit::sync_jvms() const {
  96   JVMState* jvms = this->jvms();
  97   jvms->set_bci(bci());       // Record the new bci in the JVMState
  98   jvms->set_sp(sp());         // Record the new sp in the JVMState
  99   assert(jvms_in_sync(), "jvms is now in sync");
 100   return jvms;
 101 }
 102 
 103 //--------------------------------sync_jvms_for_reexecute---------------------
 104 // Make sure our current jvms agrees with our parse state.  This version
 105 // uses the reexecute_sp for reexecuting bytecodes.
 106 JVMState* GraphKit::sync_jvms_for_reexecute() {
 107   JVMState* jvms = this->jvms();
 108   jvms->set_bci(bci());          // Record the new bci in the JVMState
 109   jvms->set_sp(reexecute_sp());  // Record the new sp in the JVMState
 110   return jvms;
 111 }
 112 
 113 #ifdef ASSERT
 114 bool GraphKit::jvms_in_sync() const {
 115   Parse* parse = is_Parse();
 116   if (parse == NULL) {
 117     if (bci() !=      jvms()->bci())          return false;
 118     if (sp()  != (int)jvms()->sp())           return false;
 119     return true;
 120   }
 121   if (jvms()->method() != parse->method())    return false;
 122   if (jvms()->bci()    != parse->bci())       return false;
 123   int jvms_sp = jvms()->sp();
 124   if (jvms_sp          != parse->sp())        return false;
 125   int jvms_depth = jvms()->depth();
 126   if (jvms_depth       != parse->depth())     return false;
 127   return true;
 128 }
 129 
 130 // Local helper checks for special internal merge points
 131 // used to accumulate and merge exception states.
 132 // They are marked by the region's in(0) edge being the map itself.
 133 // Such merge points must never "escape" into the parser at large,
 134 // until they have been handed to gvn.transform.
 135 static bool is_hidden_merge(Node* reg) {
 136   if (reg == NULL)  return false;
 137   if (reg->is_Phi()) {
 138     reg = reg->in(0);
 139     if (reg == NULL)  return false;
 140   }
 141   return reg->is_Region() && reg->in(0) != NULL && reg->in(0)->is_Root();
 142 }
 143 
 144 void GraphKit::verify_map() const {
 145   if (map() == NULL)  return;  // null map is OK
 146   assert(map()->req() <= jvms()->endoff(), "no extra garbage on map");
 147   assert(!map()->has_exceptions(),    "call add_exception_states_from 1st");
 148   assert(!is_hidden_merge(control()), "call use_exception_state, not set_map");
 149 }
 150 
 151 void GraphKit::verify_exception_state(SafePointNode* ex_map) {
 152   assert(ex_map->next_exception() == NULL, "not already part of a chain");
 153   assert(has_saved_ex_oop(ex_map), "every exception state has an ex_oop");
 154 }
 155 #endif
 156 
 157 //---------------------------stop_and_kill_map---------------------------------
 158 // Set _map to NULL, signalling a stop to further bytecode execution.
 159 // First smash the current map's control to a constant, to mark it dead.
 160 void GraphKit::stop_and_kill_map() {
 161   SafePointNode* dead_map = stop();
 162   if (dead_map != NULL) {
 163     dead_map->disconnect_inputs(NULL, C); // Mark the map as killed.
 164     assert(dead_map->is_killed(), "must be so marked");
 165   }
 166 }
 167 
 168 
 169 //--------------------------------stopped--------------------------------------
 170 // Tell if _map is NULL, or control is top.
 171 bool GraphKit::stopped() {
 172   if (map() == NULL)           return true;
 173   else if (control() == top()) return true;
 174   else                         return false;
 175 }
 176 
 177 
 178 //-----------------------------has_ex_handler----------------------------------
 179 // Tell if this method or any caller method has exception handlers.
 180 bool GraphKit::has_ex_handler() {
 181   for (JVMState* jvmsp = jvms(); jvmsp != NULL; jvmsp = jvmsp->caller()) {
 182     if (jvmsp->has_method() && jvmsp->method()->has_exception_handlers()) {
 183       return true;
 184     }
 185   }
 186   return false;
 187 }
 188 
 189 //------------------------------save_ex_oop------------------------------------
 190 // Save an exception without blowing stack contents or other JVM state.
 191 void GraphKit::set_saved_ex_oop(SafePointNode* ex_map, Node* ex_oop) {
 192   assert(!has_saved_ex_oop(ex_map), "clear ex-oop before setting again");
 193   ex_map->add_req(ex_oop);
 194   debug_only(verify_exception_state(ex_map));
 195 }
 196 
 197 inline static Node* common_saved_ex_oop(SafePointNode* ex_map, bool clear_it) {
 198   assert(GraphKit::has_saved_ex_oop(ex_map), "ex_oop must be there");
 199   Node* ex_oop = ex_map->in(ex_map->req()-1);
 200   if (clear_it)  ex_map->del_req(ex_map->req()-1);
 201   return ex_oop;
 202 }
 203 
 204 //-----------------------------saved_ex_oop------------------------------------
 205 // Recover a saved exception from its map.
 206 Node* GraphKit::saved_ex_oop(SafePointNode* ex_map) {
 207   return common_saved_ex_oop(ex_map, false);
 208 }
 209 
 210 //--------------------------clear_saved_ex_oop---------------------------------
 211 // Erase a previously saved exception from its map.
 212 Node* GraphKit::clear_saved_ex_oop(SafePointNode* ex_map) {
 213   return common_saved_ex_oop(ex_map, true);
 214 }
 215 
 216 #ifdef ASSERT
 217 //---------------------------has_saved_ex_oop----------------------------------
 218 // Erase a previously saved exception from its map.
 219 bool GraphKit::has_saved_ex_oop(SafePointNode* ex_map) {
 220   return ex_map->req() == ex_map->jvms()->endoff()+1;
 221 }
 222 #endif
 223 
 224 //-------------------------make_exception_state--------------------------------
 225 // Turn the current JVM state into an exception state, appending the ex_oop.
 226 SafePointNode* GraphKit::make_exception_state(Node* ex_oop) {
 227   sync_jvms();
 228   SafePointNode* ex_map = stop();  // do not manipulate this map any more
 229   set_saved_ex_oop(ex_map, ex_oop);
 230   return ex_map;
 231 }
 232 
 233 
 234 //--------------------------add_exception_state--------------------------------
 235 // Add an exception to my list of exceptions.
 236 void GraphKit::add_exception_state(SafePointNode* ex_map) {
 237   if (ex_map == NULL || ex_map->control() == top()) {
 238     return;
 239   }
 240 #ifdef ASSERT
 241   verify_exception_state(ex_map);
 242   if (has_exceptions()) {
 243     assert(ex_map->jvms()->same_calls_as(_exceptions->jvms()), "all collected exceptions must come from the same place");
 244   }
 245 #endif
 246 
 247   // If there is already an exception of exactly this type, merge with it.
 248   // In particular, null-checks and other low-level exceptions common up here.
 249   Node*       ex_oop  = saved_ex_oop(ex_map);
 250   const Type* ex_type = _gvn.type(ex_oop);
 251   if (ex_oop == top()) {
 252     // No action needed.
 253     return;
 254   }
 255   assert(ex_type->isa_instptr(), "exception must be an instance");
 256   for (SafePointNode* e2 = _exceptions; e2 != NULL; e2 = e2->next_exception()) {
 257     const Type* ex_type2 = _gvn.type(saved_ex_oop(e2));
 258     // We check sp also because call bytecodes can generate exceptions
 259     // both before and after arguments are popped!
 260     if (ex_type2 == ex_type
 261         && e2->_jvms->sp() == ex_map->_jvms->sp()) {
 262       combine_exception_states(ex_map, e2);
 263       return;
 264     }
 265   }
 266 
 267   // No pre-existing exception of the same type.  Chain it on the list.
 268   push_exception_state(ex_map);
 269 }
 270 
 271 //-----------------------add_exception_states_from-----------------------------
 272 void GraphKit::add_exception_states_from(JVMState* jvms) {
 273   SafePointNode* ex_map = jvms->map()->next_exception();
 274   if (ex_map != NULL) {
 275     jvms->map()->set_next_exception(NULL);
 276     for (SafePointNode* next_map; ex_map != NULL; ex_map = next_map) {
 277       next_map = ex_map->next_exception();
 278       ex_map->set_next_exception(NULL);
 279       add_exception_state(ex_map);
 280     }
 281   }
 282 }
 283 
 284 //-----------------------transfer_exceptions_into_jvms-------------------------
 285 JVMState* GraphKit::transfer_exceptions_into_jvms() {
 286   if (map() == NULL) {
 287     // We need a JVMS to carry the exceptions, but the map has gone away.
 288     // Create a scratch JVMS, cloned from any of the exception states...
 289     if (has_exceptions()) {
 290       _map = _exceptions;
 291       _map = clone_map();
 292       _map->set_next_exception(NULL);
 293       clear_saved_ex_oop(_map);
 294       debug_only(verify_map());
 295     } else {
 296       // ...or created from scratch
 297       JVMState* jvms = new (C) JVMState(_method, NULL);
 298       jvms->set_bci(_bci);
 299       jvms->set_sp(_sp);
 300       jvms->set_map(new SafePointNode(TypeFunc::Parms, jvms));
 301       set_jvms(jvms);
 302       for (uint i = 0; i < map()->req(); i++)  map()->init_req(i, top());
 303       set_all_memory(top());
 304       while (map()->req() < jvms->endoff())  map()->add_req(top());
 305     }
 306     // (This is a kludge, in case you didn't notice.)
 307     set_control(top());
 308   }
 309   JVMState* jvms = sync_jvms();
 310   assert(!jvms->map()->has_exceptions(), "no exceptions on this map yet");
 311   jvms->map()->set_next_exception(_exceptions);
 312   _exceptions = NULL;   // done with this set of exceptions
 313   return jvms;
 314 }
 315 
 316 static inline void add_n_reqs(Node* dstphi, Node* srcphi) {
 317   assert(is_hidden_merge(dstphi), "must be a special merge node");
 318   assert(is_hidden_merge(srcphi), "must be a special merge node");
 319   uint limit = srcphi->req();
 320   for (uint i = PhiNode::Input; i < limit; i++) {
 321     dstphi->add_req(srcphi->in(i));
 322   }
 323 }
 324 static inline void add_one_req(Node* dstphi, Node* src) {
 325   assert(is_hidden_merge(dstphi), "must be a special merge node");
 326   assert(!is_hidden_merge(src), "must not be a special merge node");
 327   dstphi->add_req(src);
 328 }
 329 
 330 //-----------------------combine_exception_states------------------------------
 331 // This helper function combines exception states by building phis on a
 332 // specially marked state-merging region.  These regions and phis are
 333 // untransformed, and can build up gradually.  The region is marked by
 334 // having a control input of its exception map, rather than NULL.  Such
 335 // regions do not appear except in this function, and in use_exception_state.
 336 void GraphKit::combine_exception_states(SafePointNode* ex_map, SafePointNode* phi_map) {
 337   if (failing())  return;  // dying anyway...
 338   JVMState* ex_jvms = ex_map->_jvms;
 339   assert(ex_jvms->same_calls_as(phi_map->_jvms), "consistent call chains");
 340   assert(ex_jvms->stkoff() == phi_map->_jvms->stkoff(), "matching locals");
 341   assert(ex_jvms->sp() == phi_map->_jvms->sp(), "matching stack sizes");
 342   assert(ex_jvms->monoff() == phi_map->_jvms->monoff(), "matching JVMS");
 343   assert(ex_jvms->scloff() == phi_map->_jvms->scloff(), "matching scalar replaced objects");
 344   assert(ex_map->req() == phi_map->req(), "matching maps");
 345   uint tos = ex_jvms->stkoff() + ex_jvms->sp();
 346   Node*         hidden_merge_mark = root();
 347   Node*         region  = phi_map->control();
 348   MergeMemNode* phi_mem = phi_map->merged_memory();
 349   MergeMemNode* ex_mem  = ex_map->merged_memory();
 350   if (region->in(0) != hidden_merge_mark) {
 351     // The control input is not (yet) a specially-marked region in phi_map.
 352     // Make it so, and build some phis.
 353     region = new RegionNode(2);
 354     _gvn.set_type(region, Type::CONTROL);
 355     region->set_req(0, hidden_merge_mark);  // marks an internal ex-state
 356     region->init_req(1, phi_map->control());
 357     phi_map->set_control(region);
 358     Node* io_phi = PhiNode::make(region, phi_map->i_o(), Type::ABIO);
 359     record_for_igvn(io_phi);
 360     _gvn.set_type(io_phi, Type::ABIO);
 361     phi_map->set_i_o(io_phi);
 362     for (MergeMemStream mms(phi_mem); mms.next_non_empty(); ) {
 363       Node* m = mms.memory();
 364       Node* m_phi = PhiNode::make(region, m, Type::MEMORY, mms.adr_type(C));
 365       record_for_igvn(m_phi);
 366       _gvn.set_type(m_phi, Type::MEMORY);
 367       mms.set_memory(m_phi);
 368     }
 369   }
 370 
 371   // Either or both of phi_map and ex_map might already be converted into phis.
 372   Node* ex_control = ex_map->control();
 373   // if there is special marking on ex_map also, we add multiple edges from src
 374   bool add_multiple = (ex_control->in(0) == hidden_merge_mark);
 375   // how wide was the destination phi_map, originally?
 376   uint orig_width = region->req();
 377 
 378   if (add_multiple) {
 379     add_n_reqs(region, ex_control);
 380     add_n_reqs(phi_map->i_o(), ex_map->i_o());
 381   } else {
 382     // ex_map has no merges, so we just add single edges everywhere
 383     add_one_req(region, ex_control);
 384     add_one_req(phi_map->i_o(), ex_map->i_o());
 385   }
 386   for (MergeMemStream mms(phi_mem, ex_mem); mms.next_non_empty2(); ) {
 387     if (mms.is_empty()) {
 388       // get a copy of the base memory, and patch some inputs into it
 389       const TypePtr* adr_type = mms.adr_type(C);
 390       Node* phi = mms.force_memory()->as_Phi()->slice_memory(adr_type);
 391       assert(phi->as_Phi()->region() == mms.base_memory()->in(0), "");
 392       mms.set_memory(phi);
 393       // Prepare to append interesting stuff onto the newly sliced phi:
 394       while (phi->req() > orig_width)  phi->del_req(phi->req()-1);
 395     }
 396     // Append stuff from ex_map:
 397     if (add_multiple) {
 398       add_n_reqs(mms.memory(), mms.memory2());
 399     } else {
 400       add_one_req(mms.memory(), mms.memory2());
 401     }
 402   }
 403   uint limit = ex_map->req();
 404   for (uint i = TypeFunc::Parms; i < limit; i++) {
 405     // Skip everything in the JVMS after tos.  (The ex_oop follows.)
 406     if (i == tos)  i = ex_jvms->monoff();
 407     Node* src = ex_map->in(i);
 408     Node* dst = phi_map->in(i);
 409     if (src != dst) {
 410       PhiNode* phi;
 411       if (dst->in(0) != region) {
 412         dst = phi = PhiNode::make(region, dst, _gvn.type(dst));
 413         record_for_igvn(phi);
 414         _gvn.set_type(phi, phi->type());
 415         phi_map->set_req(i, dst);
 416         // Prepare to append interesting stuff onto the new phi:
 417         while (dst->req() > orig_width)  dst->del_req(dst->req()-1);
 418       } else {
 419         assert(dst->is_Phi(), "nobody else uses a hidden region");
 420         phi = dst->as_Phi();
 421       }
 422       if (add_multiple && src->in(0) == ex_control) {
 423         // Both are phis.
 424         add_n_reqs(dst, src);
 425       } else {
 426         while (dst->req() < region->req())  add_one_req(dst, src);
 427       }
 428       const Type* srctype = _gvn.type(src);
 429       if (phi->type() != srctype) {
 430         const Type* dsttype = phi->type()->meet_speculative(srctype);
 431         if (phi->type() != dsttype) {
 432           phi->set_type(dsttype);
 433           _gvn.set_type(phi, dsttype);
 434         }
 435       }
 436     }
 437   }
 438   phi_map->merge_replaced_nodes_with(ex_map);
 439 }
 440 
 441 //--------------------------use_exception_state--------------------------------
 442 Node* GraphKit::use_exception_state(SafePointNode* phi_map) {
 443   if (failing()) { stop(); return top(); }
 444   Node* region = phi_map->control();
 445   Node* hidden_merge_mark = root();
 446   assert(phi_map->jvms()->map() == phi_map, "sanity: 1-1 relation");
 447   Node* ex_oop = clear_saved_ex_oop(phi_map);
 448   if (region->in(0) == hidden_merge_mark) {
 449     // Special marking for internal ex-states.  Process the phis now.
 450     region->set_req(0, region);  // now it's an ordinary region
 451     set_jvms(phi_map->jvms());   // ...so now we can use it as a map
 452     // Note: Setting the jvms also sets the bci and sp.
 453     set_control(_gvn.transform(region));
 454     uint tos = jvms()->stkoff() + sp();
 455     for (uint i = 1; i < tos; i++) {
 456       Node* x = phi_map->in(i);
 457       if (x->in(0) == region) {
 458         assert(x->is_Phi(), "expected a special phi");
 459         phi_map->set_req(i, _gvn.transform(x));
 460       }
 461     }
 462     for (MergeMemStream mms(merged_memory()); mms.next_non_empty(); ) {
 463       Node* x = mms.memory();
 464       if (x->in(0) == region) {
 465         assert(x->is_Phi(), "nobody else uses a hidden region");
 466         mms.set_memory(_gvn.transform(x));
 467       }
 468     }
 469     if (ex_oop->in(0) == region) {
 470       assert(ex_oop->is_Phi(), "expected a special phi");
 471       ex_oop = _gvn.transform(ex_oop);
 472     }
 473   } else {
 474     set_jvms(phi_map->jvms());
 475   }
 476 
 477   assert(!is_hidden_merge(phi_map->control()), "hidden ex. states cleared");
 478   assert(!is_hidden_merge(phi_map->i_o()), "hidden ex. states cleared");
 479   return ex_oop;
 480 }
 481 
 482 //---------------------------------java_bc-------------------------------------
 483 Bytecodes::Code GraphKit::java_bc() const {
 484   ciMethod* method = this->method();
 485   int       bci    = this->bci();
 486   if (method != NULL && bci != InvocationEntryBci)
 487     return method->java_code_at_bci(bci);
 488   else
 489     return Bytecodes::_illegal;
 490 }
 491 
 492 void GraphKit::uncommon_trap_if_should_post_on_exceptions(Deoptimization::DeoptReason reason,
 493                                                           bool must_throw) {
 494     // if the exception capability is set, then we will generate code
 495     // to check the JavaThread.should_post_on_exceptions flag to see
 496     // if we actually need to report exception events (for this
 497     // thread).  If we don't need to report exception events, we will
 498     // take the normal fast path provided by add_exception_events.  If
 499     // exception event reporting is enabled for this thread, we will
 500     // take the uncommon_trap in the BuildCutout below.
 501 
 502     // first must access the should_post_on_exceptions_flag in this thread's JavaThread
 503     Node* jthread = _gvn.transform(new ThreadLocalNode());
 504     Node* adr = basic_plus_adr(top(), jthread, in_bytes(JavaThread::should_post_on_exceptions_flag_offset()));
 505     Node* should_post_flag = make_load(control(), adr, TypeInt::INT, T_INT, Compile::AliasIdxRaw, MemNode::unordered);
 506 
 507     // Test the should_post_on_exceptions_flag vs. 0
 508     Node* chk = _gvn.transform( new CmpINode(should_post_flag, intcon(0)) );
 509     Node* tst = _gvn.transform( new BoolNode(chk, BoolTest::eq) );
 510 
 511     // Branch to slow_path if should_post_on_exceptions_flag was true
 512     { BuildCutout unless(this, tst, PROB_MAX);
 513       // Do not try anything fancy if we're notifying the VM on every throw.
 514       // Cf. case Bytecodes::_athrow in parse2.cpp.
 515       uncommon_trap(reason, Deoptimization::Action_none,
 516                     (ciKlass*)NULL, (char*)NULL, must_throw);
 517     }
 518 
 519 }
 520 
 521 //------------------------------builtin_throw----------------------------------
 522 void GraphKit::builtin_throw(Deoptimization::DeoptReason reason, Node* arg) {
 523   bool must_throw = true;
 524 
 525   if (env()->jvmti_can_post_on_exceptions()) {
 526     // check if we must post exception events, take uncommon trap if so
 527     uncommon_trap_if_should_post_on_exceptions(reason, must_throw);
 528     // here if should_post_on_exceptions is false
 529     // continue on with the normal codegen
 530   }
 531 
 532   // If this particular condition has not yet happened at this
 533   // bytecode, then use the uncommon trap mechanism, and allow for
 534   // a future recompilation if several traps occur here.
 535   // If the throw is hot, try to use a more complicated inline mechanism
 536   // which keeps execution inside the compiled code.
 537   bool treat_throw_as_hot = false;
 538   ciMethodData* md = method()->method_data();
 539 
 540   if (ProfileTraps) {
 541     if (too_many_traps(reason)) {
 542       treat_throw_as_hot = true;
 543     }
 544     // (If there is no MDO at all, assume it is early in
 545     // execution, and that any deopts are part of the
 546     // startup transient, and don't need to be remembered.)
 547 
 548     // Also, if there is a local exception handler, treat all throws
 549     // as hot if there has been at least one in this method.
 550     if (C->trap_count(reason) != 0
 551         && method()->method_data()->trap_count(reason) != 0
 552         && has_ex_handler()) {
 553         treat_throw_as_hot = true;
 554     }
 555   }
 556 
 557   // If this throw happens frequently, an uncommon trap might cause
 558   // a performance pothole.  If there is a local exception handler,
 559   // and if this particular bytecode appears to be deoptimizing often,
 560   // let us handle the throw inline, with a preconstructed instance.
 561   // Note:   If the deopt count has blown up, the uncommon trap
 562   // runtime is going to flush this nmethod, not matter what.
 563   if (treat_throw_as_hot
 564       && (!StackTraceInThrowable || OmitStackTraceInFastThrow)) {
 565     // If the throw is local, we use a pre-existing instance and
 566     // punt on the backtrace.  This would lead to a missing backtrace
 567     // (a repeat of 4292742) if the backtrace object is ever asked
 568     // for its backtrace.
 569     // Fixing this remaining case of 4292742 requires some flavor of
 570     // escape analysis.  Leave that for the future.
 571     ciInstance* ex_obj = NULL;
 572     switch (reason) {
 573     case Deoptimization::Reason_null_check:
 574       ex_obj = env()->NullPointerException_instance();
 575       break;
 576     case Deoptimization::Reason_div0_check:
 577       ex_obj = env()->ArithmeticException_instance();
 578       break;
 579     case Deoptimization::Reason_range_check:
 580       ex_obj = env()->ArrayIndexOutOfBoundsException_instance();
 581       break;
 582     case Deoptimization::Reason_class_check:
 583       if (java_bc() == Bytecodes::_aastore || java_bc() == Bytecodes::_vastore) {
 584         ex_obj = env()->ArrayStoreException_instance();
 585       } else {
 586         ex_obj = env()->ClassCastException_instance();
 587       }
 588       break;
 589     }
 590     if (failing()) { stop(); return; }  // exception allocation might fail
 591     if (ex_obj != NULL) {
 592       // Cheat with a preallocated exception object.
 593       if (C->log() != NULL)
 594         C->log()->elem("hot_throw preallocated='1' reason='%s'",
 595                        Deoptimization::trap_reason_name(reason));
 596       const TypeInstPtr* ex_con  = TypeInstPtr::make(ex_obj);
 597       Node*              ex_node = _gvn.transform(ConNode::make(ex_con));
 598 
 599       // Clear the detail message of the preallocated exception object.
 600       // Weblogic sometimes mutates the detail message of exceptions
 601       // using reflection.
 602       int offset = java_lang_Throwable::get_detailMessage_offset();
 603       const TypePtr* adr_typ = ex_con->add_offset(offset);
 604 
 605       Node *adr = basic_plus_adr(ex_node, ex_node, offset);
 606       const TypeOopPtr* val_type = TypeOopPtr::make_from_klass(env()->String_klass());
 607       // Conservatively release stores of object references.
 608       Node *store = store_oop_to_object(control(), ex_node, adr, adr_typ, null(), val_type, T_OBJECT, MemNode::release);
 609 
 610       add_exception_state(make_exception_state(ex_node));
 611       return;
 612     }
 613   }
 614 
 615   // %%% Maybe add entry to OptoRuntime which directly throws the exc.?
 616   // It won't be much cheaper than bailing to the interp., since we'll
 617   // have to pass up all the debug-info, and the runtime will have to
 618   // create the stack trace.
 619 
 620   // Usual case:  Bail to interpreter.
 621   // Reserve the right to recompile if we haven't seen anything yet.
 622 
 623   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? C->method() : NULL;
 624   Deoptimization::DeoptAction action = Deoptimization::Action_maybe_recompile;
 625   if (treat_throw_as_hot
 626       && (method()->method_data()->trap_recompiled_at(bci(), m)
 627           || C->too_many_traps(reason))) {
 628     // We cannot afford to take more traps here.  Suffer in the interpreter.
 629     if (C->log() != NULL)
 630       C->log()->elem("hot_throw preallocated='0' reason='%s' mcount='%d'",
 631                      Deoptimization::trap_reason_name(reason),
 632                      C->trap_count(reason));
 633     action = Deoptimization::Action_none;
 634   }
 635 
 636   // "must_throw" prunes the JVM state to include only the stack, if there
 637   // are no local exception handlers.  This should cut down on register
 638   // allocation time and code size, by drastically reducing the number
 639   // of in-edges on the call to the uncommon trap.
 640 
 641   uncommon_trap(reason, action, (ciKlass*)NULL, (char*)NULL, must_throw);
 642 }
 643 
 644 
 645 //----------------------------PreserveJVMState---------------------------------
 646 PreserveJVMState::PreserveJVMState(GraphKit* kit, bool clone_map) {
 647   debug_only(kit->verify_map());
 648   _kit    = kit;
 649   _map    = kit->map();   // preserve the map
 650   _sp     = kit->sp();
 651   kit->set_map(clone_map ? kit->clone_map() : NULL);
 652 #ifdef ASSERT
 653   _bci    = kit->bci();
 654   Parse* parser = kit->is_Parse();
 655   int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo();
 656   _block  = block;
 657 #endif
 658 }
 659 PreserveJVMState::~PreserveJVMState() {
 660   GraphKit* kit = _kit;
 661 #ifdef ASSERT
 662   assert(kit->bci() == _bci, "bci must not shift");
 663   Parse* parser = kit->is_Parse();
 664   int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo();
 665   assert(block == _block,    "block must not shift");
 666 #endif
 667   kit->set_map(_map);
 668   kit->set_sp(_sp);
 669 }
 670 
 671 
 672 //-----------------------------BuildCutout-------------------------------------
 673 BuildCutout::BuildCutout(GraphKit* kit, Node* p, float prob, float cnt)
 674   : PreserveJVMState(kit)
 675 {
 676   assert(p->is_Con() || p->is_Bool(), "test must be a bool");
 677   SafePointNode* outer_map = _map;   // preserved map is caller's
 678   SafePointNode* inner_map = kit->map();
 679   IfNode* iff = kit->create_and_map_if(outer_map->control(), p, prob, cnt);
 680   outer_map->set_control(kit->gvn().transform( new IfTrueNode(iff) ));
 681   inner_map->set_control(kit->gvn().transform( new IfFalseNode(iff) ));
 682 }
 683 BuildCutout::~BuildCutout() {
 684   GraphKit* kit = _kit;
 685   assert(kit->stopped(), "cutout code must stop, throw, return, etc.");
 686 }
 687 
 688 //---------------------------PreserveReexecuteState----------------------------
 689 PreserveReexecuteState::PreserveReexecuteState(GraphKit* kit) {
 690   assert(!kit->stopped(), "must call stopped() before");
 691   _kit    =    kit;
 692   _sp     =    kit->sp();
 693   _reexecute = kit->jvms()->_reexecute;
 694 }
 695 PreserveReexecuteState::~PreserveReexecuteState() {
 696   if (_kit->stopped()) return;
 697   _kit->jvms()->_reexecute = _reexecute;
 698   _kit->set_sp(_sp);
 699 }
 700 
 701 //------------------------------clone_map--------------------------------------
 702 // Implementation of PreserveJVMState
 703 //
 704 // Only clone_map(...) here. If this function is only used in the
 705 // PreserveJVMState class we may want to get rid of this extra
 706 // function eventually and do it all there.
 707 
 708 SafePointNode* GraphKit::clone_map() {
 709   if (map() == NULL)  return NULL;
 710 
 711   // Clone the memory edge first
 712   Node* mem = MergeMemNode::make(map()->memory());
 713   gvn().set_type_bottom(mem);
 714 
 715   SafePointNode *clonemap = (SafePointNode*)map()->clone();
 716   JVMState* jvms = this->jvms();
 717   JVMState* clonejvms = jvms->clone_shallow(C);
 718   clonemap->set_memory(mem);
 719   clonemap->set_jvms(clonejvms);
 720   clonejvms->set_map(clonemap);
 721   record_for_igvn(clonemap);
 722   gvn().set_type_bottom(clonemap);
 723   return clonemap;
 724 }
 725 
 726 
 727 //-----------------------------set_map_clone-----------------------------------
 728 void GraphKit::set_map_clone(SafePointNode* m) {
 729   _map = m;
 730   _map = clone_map();
 731   _map->set_next_exception(NULL);
 732   debug_only(verify_map());
 733 }
 734 
 735 
 736 //----------------------------kill_dead_locals---------------------------------
 737 // Detect any locals which are known to be dead, and force them to top.
 738 void GraphKit::kill_dead_locals() {
 739   // Consult the liveness information for the locals.  If any
 740   // of them are unused, then they can be replaced by top().  This
 741   // should help register allocation time and cut down on the size
 742   // of the deoptimization information.
 743 
 744   // This call is made from many of the bytecode handling
 745   // subroutines called from the Big Switch in do_one_bytecode.
 746   // Every bytecode which might include a slow path is responsible
 747   // for killing its dead locals.  The more consistent we
 748   // are about killing deads, the fewer useless phis will be
 749   // constructed for them at various merge points.
 750 
 751   // bci can be -1 (InvocationEntryBci).  We return the entry
 752   // liveness for the method.
 753 
 754   if (method() == NULL || method()->code_size() == 0) {
 755     // We are building a graph for a call to a native method.
 756     // All locals are live.
 757     return;
 758   }
 759 
 760   ResourceMark rm;
 761 
 762   // Consult the liveness information for the locals.  If any
 763   // of them are unused, then they can be replaced by top().  This
 764   // should help register allocation time and cut down on the size
 765   // of the deoptimization information.
 766   MethodLivenessResult live_locals = method()->liveness_at_bci(bci());
 767 
 768   int len = (int)live_locals.size();
 769   assert(len <= jvms()->loc_size(), "too many live locals");
 770   for (int local = 0; local < len; local++) {
 771     if (!live_locals.at(local)) {
 772       set_local(local, top());
 773     }
 774   }
 775 }
 776 
 777 #ifdef ASSERT
 778 //-------------------------dead_locals_are_killed------------------------------
 779 // Return true if all dead locals are set to top in the map.
 780 // Used to assert "clean" debug info at various points.
 781 bool GraphKit::dead_locals_are_killed() {
 782   if (method() == NULL || method()->code_size() == 0) {
 783     // No locals need to be dead, so all is as it should be.
 784     return true;
 785   }
 786 
 787   // Make sure somebody called kill_dead_locals upstream.
 788   ResourceMark rm;
 789   for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) {
 790     if (jvms->loc_size() == 0)  continue;  // no locals to consult
 791     SafePointNode* map = jvms->map();
 792     ciMethod* method = jvms->method();
 793     int       bci    = jvms->bci();
 794     if (jvms == this->jvms()) {
 795       bci = this->bci();  // it might not yet be synched
 796     }
 797     MethodLivenessResult live_locals = method->liveness_at_bci(bci);
 798     int len = (int)live_locals.size();
 799     if (!live_locals.is_valid() || len == 0)
 800       // This method is trivial, or is poisoned by a breakpoint.
 801       return true;
 802     assert(len == jvms->loc_size(), "live map consistent with locals map");
 803     for (int local = 0; local < len; local++) {
 804       if (!live_locals.at(local) && map->local(jvms, local) != top()) {
 805         if (PrintMiscellaneous && (Verbose || WizardMode)) {
 806           tty->print_cr("Zombie local %d: ", local);
 807           jvms->dump();
 808         }
 809         return false;
 810       }
 811     }
 812   }
 813   return true;
 814 }
 815 
 816 #endif //ASSERT
 817 
 818 // Helper function for adding JVMState and debug information to node
 819 void GraphKit::add_safepoint_edges(SafePointNode* call, bool must_throw) {
 820   // Add the safepoint edges to the call (or other safepoint).
 821 
 822   // Make sure dead locals are set to top.  This
 823   // should help register allocation time and cut down on the size
 824   // of the deoptimization information.
 825   assert(dead_locals_are_killed(), "garbage in debug info before safepoint");
 826 
 827   // Walk the inline list to fill in the correct set of JVMState's
 828   // Also fill in the associated edges for each JVMState.
 829 
 830   // If the bytecode needs to be reexecuted we need to put
 831   // the arguments back on the stack.
 832   const bool should_reexecute = jvms()->should_reexecute();
 833   JVMState* youngest_jvms = should_reexecute ? sync_jvms_for_reexecute() : sync_jvms();
 834 
 835   // NOTE: set_bci (called from sync_jvms) might reset the reexecute bit to
 836   // undefined if the bci is different.  This is normal for Parse but it
 837   // should not happen for LibraryCallKit because only one bci is processed.
 838   assert(!is_LibraryCallKit() || (jvms()->should_reexecute() == should_reexecute),
 839          "in LibraryCallKit the reexecute bit should not change");
 840 
 841   // If we are guaranteed to throw, we can prune everything but the
 842   // input to the current bytecode.
 843   bool can_prune_locals = false;
 844   uint stack_slots_not_pruned = 0;
 845   int inputs = 0, depth = 0;
 846   if (must_throw) {
 847     assert(method() == youngest_jvms->method(), "sanity");
 848     if (compute_stack_effects(inputs, depth)) {
 849       can_prune_locals = true;
 850       stack_slots_not_pruned = inputs;
 851     }
 852   }
 853 
 854   if (env()->should_retain_local_variables()) {
 855     // At any safepoint, this method can get breakpointed, which would
 856     // then require an immediate deoptimization.
 857     can_prune_locals = false;  // do not prune locals
 858     stack_slots_not_pruned = 0;
 859   }
 860 
 861   C->add_safepoint_edges(call, youngest_jvms, can_prune_locals, stack_slots_not_pruned);
 862 }
 863 
 864 bool GraphKit::compute_stack_effects(int& inputs, int& depth) {
 865   Bytecodes::Code code = java_bc();
 866   if (code == Bytecodes::_wide) {
 867     code = method()->java_code_at_bci(bci() + 1);
 868   }
 869 
 870   BasicType rtype = T_ILLEGAL;
 871   int       rsize = 0;
 872 
 873   if (code != Bytecodes::_illegal) {
 874     depth = Bytecodes::depth(code); // checkcast=0, athrow=-1
 875     rtype = Bytecodes::result_type(code); // checkcast=P, athrow=V
 876     if (rtype < T_CONFLICT)
 877       rsize = type2size[rtype];
 878   }
 879 
 880   switch (code) {
 881   case Bytecodes::_illegal:
 882     return false;
 883 
 884   case Bytecodes::_ldc:
 885   case Bytecodes::_ldc_w:
 886   case Bytecodes::_ldc2_w:
 887     inputs = 0;
 888     break;
 889 
 890   case Bytecodes::_dup:         inputs = 1;  break;
 891   case Bytecodes::_dup_x1:      inputs = 2;  break;
 892   case Bytecodes::_dup_x2:      inputs = 3;  break;
 893   case Bytecodes::_dup2:        inputs = 2;  break;
 894   case Bytecodes::_dup2_x1:     inputs = 3;  break;
 895   case Bytecodes::_dup2_x2:     inputs = 4;  break;
 896   case Bytecodes::_swap:        inputs = 2;  break;
 897   case Bytecodes::_arraylength: inputs = 1;  break;
 898 
 899   case Bytecodes::_getstatic:
 900   case Bytecodes::_putstatic:
 901   case Bytecodes::_getfield:
 902   case Bytecodes::_vgetfield:
 903   case Bytecodes::_putfield:
 904     {
 905       bool ignored_will_link;
 906       ciField* field = method()->get_field_at_bci(bci(), ignored_will_link);
 907       int      size  = field->type()->size();
 908       bool is_get = (depth >= 0), is_static = (depth & 1);
 909       inputs = (is_static ? 0 : 1);
 910       if (is_get) {
 911         depth = size - inputs;
 912       } else {
 913         inputs += size;        // putxxx pops the value from the stack
 914         depth = - inputs;
 915       }
 916     }
 917     break;
 918 
 919   case Bytecodes::_invokevirtual:
 920   case Bytecodes::_invokespecial:
 921   case Bytecodes::_invokestatic:
 922   case Bytecodes::_invokedynamic:
 923   case Bytecodes::_invokeinterface:
 924     {
 925       bool ignored_will_link;
 926       ciSignature* declared_signature = NULL;
 927       ciMethod* ignored_callee = method()->get_method_at_bci(bci(), ignored_will_link, &declared_signature);
 928       assert(declared_signature != NULL, "cannot be null");
 929       inputs   = declared_signature->arg_size_for_bc(code);
 930       int size = declared_signature->return_type()->size();
 931       depth = size - inputs;
 932     }
 933     break;
 934 
 935   case Bytecodes::_multianewarray:
 936     {
 937       ciBytecodeStream iter(method());
 938       iter.reset_to_bci(bci());
 939       iter.next();
 940       inputs = iter.get_dimensions();
 941       assert(rsize == 1, "");
 942       depth = rsize - inputs;
 943     }
 944     break;
 945 
 946   case Bytecodes::_vwithfield: {
 947     bool ignored_will_link;
 948     ciField* field = method()->get_field_at_bci(bci(), ignored_will_link);
 949     int      size  = field->type()->size();
 950     inputs = size+1;
 951     depth = rsize - inputs;
 952     break;
 953   }
 954 
 955   case Bytecodes::_ireturn:
 956   case Bytecodes::_lreturn:
 957   case Bytecodes::_freturn:
 958   case Bytecodes::_dreturn:
 959   case Bytecodes::_areturn:
 960   case Bytecodes::_vreturn:
 961     assert(rsize == -depth, "");
 962     inputs = rsize;
 963     break;
 964 
 965   case Bytecodes::_jsr:
 966   case Bytecodes::_jsr_w:
 967     inputs = 0;
 968     depth  = 1;                  // S.B. depth=1, not zero
 969     break;
 970 
 971   default:
 972     // bytecode produces a typed result
 973     inputs = rsize - depth;
 974     assert(inputs >= 0, "");
 975     break;
 976   }
 977 
 978 #ifdef ASSERT
 979   // spot check
 980   int outputs = depth + inputs;
 981   assert(outputs >= 0, "sanity");
 982   switch (code) {
 983   case Bytecodes::_checkcast: assert(inputs == 1 && outputs == 1, ""); break;
 984   case Bytecodes::_athrow:    assert(inputs == 1 && outputs == 0, ""); break;
 985   case Bytecodes::_aload_0:   assert(inputs == 0 && outputs == 1, ""); break;
 986   case Bytecodes::_return:    assert(inputs == 0 && outputs == 0, ""); break;
 987   case Bytecodes::_drem:      assert(inputs == 4 && outputs == 2, ""); break;
 988   }
 989 #endif //ASSERT
 990 
 991   return true;
 992 }
 993 
 994 
 995 
 996 //------------------------------basic_plus_adr---------------------------------
 997 Node* GraphKit::basic_plus_adr(Node* base, Node* ptr, Node* offset) {
 998   // short-circuit a common case
 999   if (offset == intcon(0))  return ptr;
1000   return _gvn.transform( new AddPNode(base, ptr, offset) );
1001 }
1002 
1003 Node* GraphKit::ConvI2L(Node* offset) {
1004   // short-circuit a common case
1005   jint offset_con = find_int_con(offset, Type::OffsetBot);
1006   if (offset_con != Type::OffsetBot) {
1007     return longcon((jlong) offset_con);
1008   }
1009   return _gvn.transform( new ConvI2LNode(offset));
1010 }
1011 
1012 Node* GraphKit::ConvI2UL(Node* offset) {
1013   juint offset_con = (juint) find_int_con(offset, Type::OffsetBot);
1014   if (offset_con != (juint) Type::OffsetBot) {
1015     return longcon((julong) offset_con);
1016   }
1017   Node* conv = _gvn.transform( new ConvI2LNode(offset));
1018   Node* mask = _gvn.transform(ConLNode::make((julong) max_juint));
1019   return _gvn.transform( new AndLNode(conv, mask) );
1020 }
1021 
1022 Node* GraphKit::ConvL2I(Node* offset) {
1023   // short-circuit a common case
1024   jlong offset_con = find_long_con(offset, (jlong)Type::OffsetBot);
1025   if (offset_con != (jlong)Type::OffsetBot) {
1026     return intcon((int) offset_con);
1027   }
1028   return _gvn.transform( new ConvL2INode(offset));
1029 }
1030 
1031 //-------------------------load_object_klass-----------------------------------
1032 Node* GraphKit::load_object_klass(Node* obj) {
1033   // Special-case a fresh allocation to avoid building nodes:
1034   Node* akls = AllocateNode::Ideal_klass(obj, &_gvn);
1035   if (akls != NULL)  return akls;
1036   Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes());
1037   return _gvn.transform(LoadKlassNode::make(_gvn, NULL, immutable_memory(), k_adr, TypeInstPtr::KLASS));
1038 }
1039 
1040 //-------------------------load_array_length-----------------------------------
1041 Node* GraphKit::load_array_length(Node* array) {
1042   // Special-case a fresh allocation to avoid building nodes:
1043   AllocateArrayNode* alloc = AllocateArrayNode::Ideal_array_allocation(array, &_gvn);
1044   Node *alen;
1045   if (alloc == NULL) {
1046     Node *r_adr = basic_plus_adr(array, arrayOopDesc::length_offset_in_bytes());
1047     alen = _gvn.transform( new LoadRangeNode(0, immutable_memory(), r_adr, TypeInt::POS));
1048   } else {
1049     alen = alloc->Ideal_length();
1050     Node* ccast = alloc->make_ideal_length(_gvn.type(array)->is_oopptr(), &_gvn);
1051     if (ccast != alen) {
1052       alen = _gvn.transform(ccast);
1053     }
1054   }
1055   return alen;
1056 }
1057 
1058 //------------------------------do_null_check----------------------------------
1059 // Helper function to do a NULL pointer check.  Returned value is
1060 // the incoming address with NULL casted away.  You are allowed to use the
1061 // not-null value only if you are control dependent on the test.
1062 #ifndef PRODUCT
1063 extern int explicit_null_checks_inserted,
1064            explicit_null_checks_elided;
1065 #endif
1066 Node* GraphKit::null_check_common(Node* value, BasicType type,
1067                                   // optional arguments for variations:
1068                                   bool assert_null,
1069                                   Node* *null_control,
1070                                   bool speculative) {
1071   assert(!assert_null || null_control == NULL, "not both at once");
1072   if (stopped())  return top();
1073   NOT_PRODUCT(explicit_null_checks_inserted++);
1074 
1075   // Construct NULL check
1076   Node *chk = NULL;
1077   switch(type) {
1078     case T_LONG   : chk = new CmpLNode(value, _gvn.zerocon(T_LONG)); break;
1079     case T_INT    : chk = new CmpINode(value, _gvn.intcon(0)); break;
1080     case T_VALUETYPE : // fall through
1081     case T_ARRAY  : // fall through
1082       type = T_OBJECT;  // simplify further tests
1083     case T_OBJECT : {
1084       const Type *t = _gvn.type( value );
1085 
1086       const TypeOopPtr* tp = t->isa_oopptr();
1087       if (tp != NULL && tp->klass() != NULL && !tp->klass()->is_loaded()
1088           // Only for do_null_check, not any of its siblings:
1089           && !assert_null && null_control == NULL) {
1090         // Usually, any field access or invocation on an unloaded oop type
1091         // will simply fail to link, since the statically linked class is
1092         // likely also to be unloaded.  However, in -Xcomp mode, sometimes
1093         // the static class is loaded but the sharper oop type is not.
1094         // Rather than checking for this obscure case in lots of places,
1095         // we simply observe that a null check on an unloaded class
1096         // will always be followed by a nonsense operation, so we
1097         // can just issue the uncommon trap here.
1098         // Our access to the unloaded class will only be correct
1099         // after it has been loaded and initialized, which requires
1100         // a trip through the interpreter.
1101 #ifndef PRODUCT
1102         if (WizardMode) { tty->print("Null check of unloaded "); tp->klass()->print(); tty->cr(); }
1103 #endif
1104         uncommon_trap(Deoptimization::Reason_unloaded,
1105                       Deoptimization::Action_reinterpret,
1106                       tp->klass(), "!loaded");
1107         return top();
1108       }
1109 
1110       if (assert_null) {
1111         // See if the type is contained in NULL_PTR.
1112         // If so, then the value is already null.
1113         if (t->higher_equal(TypePtr::NULL_PTR)) {
1114           NOT_PRODUCT(explicit_null_checks_elided++);
1115           return value;           // Elided null assert quickly!
1116         }
1117       } else {
1118         // See if mixing in the NULL pointer changes type.
1119         // If so, then the NULL pointer was not allowed in the original
1120         // type.  In other words, "value" was not-null.
1121         if (t->meet(TypePtr::NULL_PTR) != t->remove_speculative()) {
1122           // same as: if (!TypePtr::NULL_PTR->higher_equal(t)) ...
1123           NOT_PRODUCT(explicit_null_checks_elided++);
1124           return value;           // Elided null check quickly!
1125         }
1126       }
1127       chk = new CmpPNode( value, null() );
1128       break;
1129     }
1130 
1131     default:
1132       fatal("unexpected type: %s", type2name(type));
1133   }
1134   assert(chk != NULL, "sanity check");
1135   chk = _gvn.transform(chk);
1136 
1137   BoolTest::mask btest = assert_null ? BoolTest::eq : BoolTest::ne;
1138   BoolNode *btst = new BoolNode( chk, btest);
1139   Node   *tst = _gvn.transform( btst );
1140 
1141   //-----------
1142   // if peephole optimizations occurred, a prior test existed.
1143   // If a prior test existed, maybe it dominates as we can avoid this test.
1144   if (tst != btst && type == T_OBJECT) {
1145     // At this point we want to scan up the CFG to see if we can
1146     // find an identical test (and so avoid this test altogether).
1147     Node *cfg = control();
1148     int depth = 0;
1149     while( depth < 16 ) {       // Limit search depth for speed
1150       if( cfg->Opcode() == Op_IfTrue &&
1151           cfg->in(0)->in(1) == tst ) {
1152         // Found prior test.  Use "cast_not_null" to construct an identical
1153         // CastPP (and hence hash to) as already exists for the prior test.
1154         // Return that casted value.
1155         if (assert_null) {
1156           replace_in_map(value, null());
1157           return null();  // do not issue the redundant test
1158         }
1159         Node *oldcontrol = control();
1160         set_control(cfg);
1161         Node *res = cast_not_null(value);
1162         set_control(oldcontrol);
1163         NOT_PRODUCT(explicit_null_checks_elided++);
1164         return res;
1165       }
1166       cfg = IfNode::up_one_dom(cfg, /*linear_only=*/ true);
1167       if (cfg == NULL)  break;  // Quit at region nodes
1168       depth++;
1169     }
1170   }
1171 
1172   //-----------
1173   // Branch to failure if null
1174   float ok_prob = PROB_MAX;  // a priori estimate:  nulls never happen
1175   Deoptimization::DeoptReason reason;
1176   if (assert_null) {
1177     reason = Deoptimization::Reason_null_assert;
1178   } else if (type == T_OBJECT) {
1179     reason = Deoptimization::reason_null_check(speculative);
1180   } else {
1181     reason = Deoptimization::Reason_div0_check;
1182   }
1183   // %%% Since Reason_unhandled is not recorded on a per-bytecode basis,
1184   // ciMethodData::has_trap_at will return a conservative -1 if any
1185   // must-be-null assertion has failed.  This could cause performance
1186   // problems for a method after its first do_null_assert failure.
1187   // Consider using 'Reason_class_check' instead?
1188 
1189   // To cause an implicit null check, we set the not-null probability
1190   // to the maximum (PROB_MAX).  For an explicit check the probability
1191   // is set to a smaller value.
1192   if (null_control != NULL || too_many_traps(reason)) {
1193     // probability is less likely
1194     ok_prob =  PROB_LIKELY_MAG(3);
1195   } else if (!assert_null &&
1196              (ImplicitNullCheckThreshold > 0) &&
1197              method() != NULL &&
1198              (method()->method_data()->trap_count(reason)
1199               >= (uint)ImplicitNullCheckThreshold)) {
1200     ok_prob =  PROB_LIKELY_MAG(3);
1201   }
1202 
1203   if (null_control != NULL) {
1204     IfNode* iff = create_and_map_if(control(), tst, ok_prob, COUNT_UNKNOWN);
1205     Node* null_true = _gvn.transform( new IfFalseNode(iff));
1206     set_control(      _gvn.transform( new IfTrueNode(iff)));
1207 #ifndef PRODUCT
1208     if (null_true == top()) {
1209       explicit_null_checks_elided++;
1210     }
1211 #endif
1212     (*null_control) = null_true;
1213   } else {
1214     BuildCutout unless(this, tst, ok_prob);
1215     // Check for optimizer eliding test at parse time
1216     if (stopped()) {
1217       // Failure not possible; do not bother making uncommon trap.
1218       NOT_PRODUCT(explicit_null_checks_elided++);
1219     } else if (assert_null) {
1220       uncommon_trap(reason,
1221                     Deoptimization::Action_make_not_entrant,
1222                     NULL, "assert_null");
1223     } else {
1224       replace_in_map(value, zerocon(type));
1225       builtin_throw(reason);
1226     }
1227   }
1228 
1229   // Must throw exception, fall-thru not possible?
1230   if (stopped()) {
1231     return top();               // No result
1232   }
1233 
1234   if (assert_null) {
1235     // Cast obj to null on this path.
1236     replace_in_map(value, zerocon(type));
1237     return zerocon(type);
1238   }
1239 
1240   // Cast obj to not-null on this path, if there is no null_control.
1241   // (If there is a null_control, a non-null value may come back to haunt us.)
1242   if (type == T_OBJECT) {
1243     Node* cast = cast_not_null(value, false);
1244     if (null_control == NULL || (*null_control) == top())
1245       replace_in_map(value, cast);
1246     value = cast;
1247   }
1248 
1249   return value;
1250 }
1251 
1252 
1253 //------------------------------cast_not_null----------------------------------
1254 // Cast obj to not-null on this path
1255 Node* GraphKit::cast_not_null(Node* obj, bool do_replace_in_map) {
1256   const Type *t = _gvn.type(obj);
1257   const Type *t_not_null = t->join_speculative(TypePtr::NOTNULL);
1258   // Object is already not-null?
1259   if( t == t_not_null ) return obj;
1260 
1261   Node *cast = new CastPPNode(obj,t_not_null);
1262   cast->init_req(0, control());
1263   cast = _gvn.transform( cast );
1264 
1265   // Scan for instances of 'obj' in the current JVM mapping.
1266   // These instances are known to be not-null after the test.
1267   if (do_replace_in_map)
1268     replace_in_map(obj, cast);
1269 
1270   return cast;                  // Return casted value
1271 }
1272 
1273 
1274 //--------------------------replace_in_map-------------------------------------
1275 void GraphKit::replace_in_map(Node* old, Node* neww) {
1276   if (old == neww) {
1277     return;
1278   }
1279 
1280   map()->replace_edge(old, neww);
1281 
1282   // Note: This operation potentially replaces any edge
1283   // on the map.  This includes locals, stack, and monitors
1284   // of the current (innermost) JVM state.
1285 
1286   // don't let inconsistent types from profiling escape this
1287   // method
1288 
1289   const Type* told = _gvn.type(old);
1290   const Type* tnew = _gvn.type(neww);
1291 
1292   if (!tnew->higher_equal(told)) {
1293     return;
1294   }
1295 
1296   map()->record_replaced_node(old, neww);
1297 }
1298 
1299 
1300 //=============================================================================
1301 //--------------------------------memory---------------------------------------
1302 Node* GraphKit::memory(uint alias_idx) {
1303   MergeMemNode* mem = merged_memory();
1304   Node* p = mem->memory_at(alias_idx);
1305   _gvn.set_type(p, Type::MEMORY);  // must be mapped
1306   return p;
1307 }
1308 
1309 //-----------------------------reset_memory------------------------------------
1310 Node* GraphKit::reset_memory() {
1311   Node* mem = map()->memory();
1312   // do not use this node for any more parsing!
1313   debug_only( map()->set_memory((Node*)NULL) );
1314   return _gvn.transform( mem );
1315 }
1316 
1317 //------------------------------set_all_memory---------------------------------
1318 void GraphKit::set_all_memory(Node* newmem) {
1319   Node* mergemem = MergeMemNode::make(newmem);
1320   gvn().set_type_bottom(mergemem);
1321   map()->set_memory(mergemem);
1322 }
1323 
1324 //------------------------------set_all_memory_call----------------------------
1325 void GraphKit::set_all_memory_call(Node* call, bool separate_io_proj) {
1326   Node* newmem = _gvn.transform( new ProjNode(call, TypeFunc::Memory, separate_io_proj) );
1327   set_all_memory(newmem);
1328 }
1329 
1330 //=============================================================================
1331 //
1332 // parser factory methods for MemNodes
1333 //
1334 // These are layered on top of the factory methods in LoadNode and StoreNode,
1335 // and integrate with the parser's memory state and _gvn engine.
1336 //
1337 
1338 // factory methods in "int adr_idx"
1339 Node* GraphKit::make_load(Node* ctl, Node* adr, const Type* t, BasicType bt,
1340                           int adr_idx,
1341                           MemNode::MemOrd mo,
1342                           LoadNode::ControlDependency control_dependency,
1343                           bool require_atomic_access,
1344                           bool unaligned,
1345                           bool mismatched) {
1346   assert(adr_idx != Compile::AliasIdxTop, "use other make_load factory" );
1347   const TypePtr* adr_type = NULL; // debug-mode-only argument
1348   debug_only(adr_type = C->get_adr_type(adr_idx));
1349   Node* mem = memory(adr_idx);
1350   Node* ld;
1351   if (require_atomic_access && bt == T_LONG) {
1352     ld = LoadLNode::make_atomic(ctl, mem, adr, adr_type, t, mo, control_dependency, unaligned, mismatched);
1353   } else if (require_atomic_access && bt == T_DOUBLE) {
1354     ld = LoadDNode::make_atomic(ctl, mem, adr, adr_type, t, mo, control_dependency, unaligned, mismatched);
1355   } else {
1356     ld = LoadNode::make(_gvn, ctl, mem, adr, adr_type, t, bt, mo, control_dependency, unaligned, mismatched);
1357   }
1358   ld = _gvn.transform(ld);
1359 
1360   if (bt == T_VALUETYPE) {
1361     // Load non-flattened value type from memory. Add a null check and let the
1362     // interpreter take care of initializing the field to the default value type.
1363     Node* null_ctl = top();
1364     ld = null_check_common(ld, bt, false, &null_ctl, false);
1365     if (null_ctl != top()) {
1366       assert(!adr_type->isa_aryptr(), "value type array must be initialized");
1367       PreserveJVMState pjvms(this);
1368       set_control(null_ctl);
1369       uncommon_trap(Deoptimization::reason_null_check(false), Deoptimization::Action_maybe_recompile,
1370                     t->is_valuetypeptr()->value_type()->value_klass(), "uninitialized non-flattened value type");
1371     }
1372     ld = ValueTypeNode::make(gvn(), map()->memory(), ld);
1373   } else if ((bt == T_OBJECT) && C->do_escape_analysis() || C->eliminate_boxing()) {
1374     // Improve graph before escape analysis and boxing elimination.
1375     record_for_igvn(ld);
1376   }
1377   return ld;
1378 }
1379 
1380 Node* GraphKit::store_to_memory(Node* ctl, Node* adr, Node *val, BasicType bt,
1381                                 int adr_idx,
1382                                 MemNode::MemOrd mo,
1383                                 bool require_atomic_access,
1384                                 bool unaligned,
1385                                 bool mismatched) {
1386   assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
1387   const TypePtr* adr_type = NULL;
1388   debug_only(adr_type = C->get_adr_type(adr_idx));
1389   Node *mem = memory(adr_idx);
1390   Node* st;
1391   if (require_atomic_access && bt == T_LONG) {
1392     st = StoreLNode::make_atomic(ctl, mem, adr, adr_type, val, mo);
1393   } else if (require_atomic_access && bt == T_DOUBLE) {
1394     st = StoreDNode::make_atomic(ctl, mem, adr, adr_type, val, mo);
1395   } else {
1396     st = StoreNode::make(_gvn, ctl, mem, adr, adr_type, val, bt, mo);
1397   }
1398   if (unaligned) {
1399     st->as_Store()->set_unaligned_access();
1400   }
1401   if (mismatched) {
1402     st->as_Store()->set_mismatched_access();
1403   }
1404   st = _gvn.transform(st);
1405   set_memory(st, adr_idx);
1406   // Back-to-back stores can only remove intermediate store with DU info
1407   // so push on worklist for optimizer.
1408   if (mem->req() > MemNode::Address && adr == mem->in(MemNode::Address))
1409     record_for_igvn(st);
1410 
1411   return st;
1412 }
1413 
1414 
1415 void GraphKit::pre_barrier(bool do_load,
1416                            Node* ctl,
1417                            Node* obj,
1418                            Node* adr,
1419                            uint  adr_idx,
1420                            Node* val,
1421                            const TypeOopPtr* val_type,
1422                            Node* pre_val,
1423                            BasicType bt) {
1424 
1425   BarrierSet* bs = Universe::heap()->barrier_set();
1426   set_control(ctl);
1427   switch (bs->kind()) {
1428     case BarrierSet::G1SATBCTLogging:
1429       g1_write_barrier_pre(do_load, obj, adr, adr_idx, val, val_type, pre_val, bt);
1430       break;
1431 
1432     case BarrierSet::CardTableForRS:
1433     case BarrierSet::CardTableExtension:
1434     case BarrierSet::ModRef:
1435       break;
1436 
1437     default      :
1438       ShouldNotReachHere();
1439 
1440   }
1441 }
1442 
1443 bool GraphKit::can_move_pre_barrier() const {
1444   BarrierSet* bs = Universe::heap()->barrier_set();
1445   switch (bs->kind()) {
1446     case BarrierSet::G1SATBCTLogging:
1447       return true; // Can move it if no safepoint
1448 
1449     case BarrierSet::CardTableForRS:
1450     case BarrierSet::CardTableExtension:
1451     case BarrierSet::ModRef:
1452       return true; // There is no pre-barrier
1453 
1454     default      :
1455       ShouldNotReachHere();
1456   }
1457   return false;
1458 }
1459 
1460 void GraphKit::post_barrier(Node* ctl,
1461                             Node* store,
1462                             Node* obj,
1463                             Node* adr,
1464                             uint  adr_idx,
1465                             Node* val,
1466                             BasicType bt,
1467                             bool use_precise) {
1468   BarrierSet* bs = Universe::heap()->barrier_set();
1469   set_control(ctl);
1470   switch (bs->kind()) {
1471     case BarrierSet::G1SATBCTLogging:
1472       g1_write_barrier_post(store, obj, adr, adr_idx, val, bt, use_precise);
1473       break;
1474 
1475     case BarrierSet::CardTableForRS:
1476     case BarrierSet::CardTableExtension:
1477       write_barrier_post(store, obj, adr, adr_idx, val, use_precise);
1478       break;
1479 
1480     case BarrierSet::ModRef:
1481       break;
1482 
1483     default      :
1484       ShouldNotReachHere();
1485 
1486   }
1487 }
1488 
1489 Node* GraphKit::store_oop(Node* ctl,
1490                           Node* obj,
1491                           Node* adr,
1492                           const TypePtr* adr_type,
1493                           Node* val,
1494                           const TypeOopPtr* val_type,
1495                           BasicType bt,
1496                           bool use_precise,
1497                           MemNode::MemOrd mo,
1498                           bool mismatched) {
1499   // Transformation of a value which could be NULL pointer (CastPP #NULL)
1500   // could be delayed during Parse (for example, in adjust_map_after_if()).
1501   // Execute transformation here to avoid barrier generation in such case.
1502   if (_gvn.type(val) == TypePtr::NULL_PTR)
1503     val = _gvn.makecon(TypePtr::NULL_PTR);
1504 
1505   set_control(ctl);
1506   if (stopped()) return top(); // Dead path ?
1507 
1508   assert(bt == T_OBJECT || bt == T_VALUETYPE, "sanity");
1509   assert(val != NULL, "not dead path");
1510   uint adr_idx = C->get_alias_index(adr_type);
1511   assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
1512 
1513   if (bt == T_VALUETYPE) {
1514     // Allocate value type and store oop
1515     val = val->as_ValueType()->allocate(this);
1516   }
1517 
1518   pre_barrier(true /* do_load */,
1519               control(), obj, adr, adr_idx, val, val_type,
1520               NULL /* pre_val */,
1521               bt);
1522 
1523   Node* store = store_to_memory(control(), adr, val, bt, adr_idx, mo, mismatched);
1524   post_barrier(control(), store, obj, adr, adr_idx, val, bt, use_precise);
1525   return store;
1526 }
1527 
1528 // Could be an array or object we don't know at compile time (unsafe ref.)
1529 Node* GraphKit::store_oop_to_unknown(Node* ctl,
1530                              Node* obj,   // containing obj
1531                              Node* adr,  // actual adress to store val at
1532                              const TypePtr* adr_type,
1533                              Node* val,
1534                              BasicType bt,
1535                              MemNode::MemOrd mo,
1536                              bool mismatched) {
1537   Compile::AliasType* at = C->alias_type(adr_type);
1538   const TypeOopPtr* val_type = NULL;
1539   if (adr_type->isa_instptr()) {
1540     if (at->field() != NULL) {
1541       // known field.  This code is a copy of the do_put_xxx logic.
1542       ciField* field = at->field();
1543       if (!field->type()->is_loaded()) {
1544         val_type = TypeInstPtr::BOTTOM;
1545       } else {
1546         val_type = TypeOopPtr::make_from_klass(field->type()->as_klass());
1547       }
1548     }
1549   } else if (adr_type->isa_aryptr()) {
1550     val_type = adr_type->is_aryptr()->elem()->make_oopptr();
1551   }
1552   if (val_type == NULL) {
1553     val_type = TypeInstPtr::BOTTOM;
1554   }
1555   return store_oop(ctl, obj, adr, adr_type, val, val_type, bt, true, mo, mismatched);
1556 }
1557 
1558 
1559 //-------------------------array_element_address-------------------------
1560 Node* GraphKit::array_element_address(Node* ary, Node* idx, BasicType elembt,
1561                                       const TypeInt* sizetype, Node* ctrl) {
1562   uint shift  = exact_log2(type2aelembytes(elembt));
1563   ciKlass* arytype_klass = _gvn.type(ary)->is_aryptr()->klass();
1564   if (arytype_klass->is_value_array_klass()) {
1565     ciValueArrayKlass* vak = arytype_klass->as_value_array_klass();
1566     shift = vak->log2_element_size();
1567   }
1568   uint header = arrayOopDesc::base_offset_in_bytes(elembt);
1569 
1570   // short-circuit a common case (saves lots of confusing waste motion)
1571   jint idx_con = find_int_con(idx, -1);
1572   if (idx_con >= 0) {
1573     intptr_t offset = header + ((intptr_t)idx_con << shift);
1574     return basic_plus_adr(ary, offset);
1575   }
1576 
1577   // must be correct type for alignment purposes
1578   Node* base  = basic_plus_adr(ary, header);
1579   idx = Compile::conv_I2X_index(&_gvn, idx, sizetype, ctrl);
1580   Node* scale = _gvn.transform( new LShiftXNode(idx, intcon(shift)) );
1581   return basic_plus_adr(ary, base, scale);
1582 }
1583 
1584 //-------------------------load_array_element-------------------------
1585 Node* GraphKit::load_array_element(Node* ctl, Node* ary, Node* idx, const TypeAryPtr* arytype) {
1586   const Type* elemtype = arytype->elem();
1587   BasicType elembt = elemtype->array_element_basic_type();
1588   assert(elembt != T_VALUETYPE, "value types are not supported by this method");
1589   Node* adr = array_element_address(ary, idx, elembt, arytype->size());
1590   if (elembt == T_NARROWOOP) {
1591     elembt = T_OBJECT; // To satisfy switch in LoadNode::make()
1592   }
1593   Node* ld = make_load(ctl, adr, elemtype, elembt, arytype, MemNode::unordered);
1594   return ld;
1595 }
1596 
1597 //-------------------------set_arguments_for_java_call-------------------------
1598 // Arguments (pre-popped from the stack) are taken from the JVMS.
1599 void GraphKit::set_arguments_for_java_call(CallJavaNode* call) {
1600   // Add the call arguments:
1601   const TypeTuple* domain = call->tf()->domain_sig();
1602   uint nargs = domain->cnt();
1603   for (uint i = TypeFunc::Parms, idx = TypeFunc::Parms; i < nargs; i++) {
1604     Node* arg = argument(i-TypeFunc::Parms);
1605     if (ValueTypePassFieldsAsArgs) {
1606       if (arg->is_ValueType()) {
1607         ValueTypeNode* vt = arg->as_ValueType();
1608         if (domain->field_at(i)->is_valuetypeptr()->klass() != C->env()->___Value_klass()) {
1609           // We don't pass value type arguments by reference but instead
1610           // pass each field of the value type
1611           idx += vt->pass_fields(call, idx, *this);
1612           // If a value type argument is passed as fields, attach the Method* to the call site
1613           // to be able to access the extended signature later via attached_method_before_pc().
1614           // For example, see CompiledMethod::preserve_callee_argument_oops().
1615           call->set_override_symbolic_info(true);
1616         } else {
1617           arg = arg->as_ValueType()->allocate(this);
1618           call->init_req(idx, arg);
1619           idx++;
1620         }
1621       } else {
1622         call->init_req(idx, arg);
1623         idx++;
1624       }
1625     } else {
1626       if (arg->is_ValueType()) {
1627         // Pass value type argument via oop to callee
1628         arg = arg->as_ValueType()->allocate(this);
1629       }
1630       call->init_req(i, arg);
1631     }
1632   }
1633 }
1634 
1635 //---------------------------set_edges_for_java_call---------------------------
1636 // Connect a newly created call into the current JVMS.
1637 // A return value node (if any) is returned from set_edges_for_java_call.
1638 void GraphKit::set_edges_for_java_call(CallJavaNode* call, bool must_throw, bool separate_io_proj) {
1639 
1640   // Add the predefined inputs:
1641   call->init_req( TypeFunc::Control, control() );
1642   call->init_req( TypeFunc::I_O    , i_o() );
1643   call->init_req( TypeFunc::Memory , reset_memory() );
1644   call->init_req( TypeFunc::FramePtr, frameptr() );
1645   call->init_req( TypeFunc::ReturnAdr, top() );
1646 
1647   add_safepoint_edges(call, must_throw);
1648 
1649   Node* xcall = _gvn.transform(call);
1650 
1651   if (xcall == top()) {
1652     set_control(top());
1653     return;
1654   }
1655   assert(xcall == call, "call identity is stable");
1656 
1657   // Re-use the current map to produce the result.
1658 
1659   set_control(_gvn.transform(new ProjNode(call, TypeFunc::Control)));
1660   set_i_o(    _gvn.transform(new ProjNode(call, TypeFunc::I_O    , separate_io_proj)));
1661   set_all_memory_call(xcall, separate_io_proj);
1662 
1663   //return xcall;   // no need, caller already has it
1664 }
1665 
1666 Node* GraphKit::set_results_for_java_call(CallJavaNode* call, bool separate_io_proj) {
1667   if (stopped())  return top();  // maybe the call folded up?
1668 
1669   // Capture the return value, if any.
1670   Node* ret;
1671   if (call->method() == NULL ||
1672       call->method()->return_type()->basic_type() == T_VOID)
1673         ret = top();
1674   else {
1675     if (!call->tf()->returns_value_type_as_fields()) {
1676       ret = _gvn.transform(new ProjNode(call, TypeFunc::Parms));
1677     } else {
1678       // Return of multiple values (value type fields): we create a
1679       // ValueType node, each field is a projection from the call.
1680       const TypeTuple *range_sig = call->tf()->range_sig();
1681       const Type* t = range_sig->field_at(TypeFunc::Parms);
1682       assert(t->isa_valuetypeptr(), "only value types for multiple return values");
1683       ciValueKlass* vk = t->is_valuetypeptr()->value_type()->value_klass();
1684       ret = C->create_vt_node(call, vk, vk, 0, TypeFunc::Parms+1, false);
1685     }
1686   }
1687 
1688   // Note:  Since any out-of-line call can produce an exception,
1689   // we always insert an I_O projection from the call into the result.
1690 
1691   make_slow_call_ex(call, env()->Throwable_klass(), separate_io_proj);
1692 
1693   if (separate_io_proj) {
1694     // The caller requested separate projections be used by the fall
1695     // through and exceptional paths, so replace the projections for
1696     // the fall through path.
1697     set_i_o(_gvn.transform( new ProjNode(call, TypeFunc::I_O) ));
1698     set_all_memory(_gvn.transform( new ProjNode(call, TypeFunc::Memory) ));
1699   }
1700   return ret;
1701 }
1702 
1703 //--------------------set_predefined_input_for_runtime_call--------------------
1704 // Reading and setting the memory state is way conservative here.
1705 // The real problem is that I am not doing real Type analysis on memory,
1706 // so I cannot distinguish card mark stores from other stores.  Across a GC
1707 // point the Store Barrier and the card mark memory has to agree.  I cannot
1708 // have a card mark store and its barrier split across the GC point from
1709 // either above or below.  Here I get that to happen by reading ALL of memory.
1710 // A better answer would be to separate out card marks from other memory.
1711 // For now, return the input memory state, so that it can be reused
1712 // after the call, if this call has restricted memory effects.
1713 Node* GraphKit::set_predefined_input_for_runtime_call(SafePointNode* call) {
1714   // Set fixed predefined input arguments
1715   Node* memory = reset_memory();
1716   call->init_req( TypeFunc::Control,   control()  );
1717   call->init_req( TypeFunc::I_O,       top()      ); // does no i/o
1718   call->init_req( TypeFunc::Memory,    memory     ); // may gc ptrs
1719   call->init_req( TypeFunc::FramePtr,  frameptr() );
1720   call->init_req( TypeFunc::ReturnAdr, top()      );
1721   return memory;
1722 }
1723 
1724 //-------------------set_predefined_output_for_runtime_call--------------------
1725 // Set control and memory (not i_o) from the call.
1726 // If keep_mem is not NULL, use it for the output state,
1727 // except for the RawPtr output of the call, if hook_mem is TypeRawPtr::BOTTOM.
1728 // If hook_mem is NULL, this call produces no memory effects at all.
1729 // If hook_mem is a Java-visible memory slice (such as arraycopy operands),
1730 // then only that memory slice is taken from the call.
1731 // In the last case, we must put an appropriate memory barrier before
1732 // the call, so as to create the correct anti-dependencies on loads
1733 // preceding the call.
1734 void GraphKit::set_predefined_output_for_runtime_call(Node* call,
1735                                                       Node* keep_mem,
1736                                                       const TypePtr* hook_mem) {
1737   // no i/o
1738   set_control(_gvn.transform( new ProjNode(call,TypeFunc::Control) ));
1739   if (keep_mem) {
1740     // First clone the existing memory state
1741     set_all_memory(keep_mem);
1742     if (hook_mem != NULL) {
1743       // Make memory for the call
1744       Node* mem = _gvn.transform( new ProjNode(call, TypeFunc::Memory) );
1745       // Set the RawPtr memory state only.  This covers all the heap top/GC stuff
1746       // We also use hook_mem to extract specific effects from arraycopy stubs.
1747       set_memory(mem, hook_mem);
1748     }
1749     // ...else the call has NO memory effects.
1750 
1751     // Make sure the call advertises its memory effects precisely.
1752     // This lets us build accurate anti-dependences in gcm.cpp.
1753     assert(C->alias_type(call->adr_type()) == C->alias_type(hook_mem),
1754            "call node must be constructed correctly");
1755   } else {
1756     assert(hook_mem == NULL, "");
1757     // This is not a "slow path" call; all memory comes from the call.
1758     set_all_memory_call(call);
1759   }
1760 }
1761 
1762 
1763 // Replace the call with the current state of the kit.
1764 void GraphKit::replace_call(CallNode* call, Node* result, bool do_replaced_nodes) {
1765   JVMState* ejvms = NULL;
1766   if (has_exceptions()) {
1767     ejvms = transfer_exceptions_into_jvms();
1768   }
1769 
1770   ReplacedNodes replaced_nodes = map()->replaced_nodes();
1771   ReplacedNodes replaced_nodes_exception;
1772   Node* ex_ctl = top();
1773 
1774   SafePointNode* final_state = stop();
1775 
1776   // Find all the needed outputs of this call
1777   CallProjections callprojs;
1778   call->extract_projections(&callprojs, true);
1779 
1780   Node* init_mem = call->in(TypeFunc::Memory);
1781   Node* final_mem = final_state->in(TypeFunc::Memory);
1782   Node* final_ctl = final_state->in(TypeFunc::Control);
1783   Node* final_io = final_state->in(TypeFunc::I_O);
1784 
1785   // Replace all the old call edges with the edges from the inlining result
1786   if (callprojs.fallthrough_catchproj != NULL) {
1787     C->gvn_replace_by(callprojs.fallthrough_catchproj, final_ctl);
1788   }
1789   if (callprojs.fallthrough_memproj != NULL) {
1790     if (final_mem->is_MergeMem()) {
1791       // Parser's exits MergeMem was not transformed but may be optimized
1792       final_mem = _gvn.transform(final_mem);
1793     }
1794     C->gvn_replace_by(callprojs.fallthrough_memproj,   final_mem);
1795   }
1796   if (callprojs.fallthrough_ioproj != NULL) {
1797     C->gvn_replace_by(callprojs.fallthrough_ioproj,    final_io);
1798   }
1799 
1800   // Replace the result with the new result if it exists and is used
1801   if (callprojs.resproj != NULL && result != NULL) {
1802     C->gvn_replace_by(callprojs.resproj, result);
1803   }
1804 
1805   if (ejvms == NULL) {
1806     // No exception edges to simply kill off those paths
1807     if (callprojs.catchall_catchproj != NULL) {
1808       C->gvn_replace_by(callprojs.catchall_catchproj, C->top());
1809     }
1810     if (callprojs.catchall_memproj != NULL) {
1811       C->gvn_replace_by(callprojs.catchall_memproj,   C->top());
1812     }
1813     if (callprojs.catchall_ioproj != NULL) {
1814       C->gvn_replace_by(callprojs.catchall_ioproj,    C->top());
1815     }
1816     // Replace the old exception object with top
1817     if (callprojs.exobj != NULL) {
1818       C->gvn_replace_by(callprojs.exobj, C->top());
1819     }
1820   } else {
1821     GraphKit ekit(ejvms);
1822 
1823     // Load my combined exception state into the kit, with all phis transformed:
1824     SafePointNode* ex_map = ekit.combine_and_pop_all_exception_states();
1825     replaced_nodes_exception = ex_map->replaced_nodes();
1826 
1827     Node* ex_oop = ekit.use_exception_state(ex_map);
1828 
1829     if (callprojs.catchall_catchproj != NULL) {
1830       C->gvn_replace_by(callprojs.catchall_catchproj, ekit.control());
1831       ex_ctl = ekit.control();
1832     }
1833     if (callprojs.catchall_memproj != NULL) {
1834       C->gvn_replace_by(callprojs.catchall_memproj,   ekit.reset_memory());
1835     }
1836     if (callprojs.catchall_ioproj != NULL) {
1837       C->gvn_replace_by(callprojs.catchall_ioproj,    ekit.i_o());
1838     }
1839 
1840     // Replace the old exception object with the newly created one
1841     if (callprojs.exobj != NULL) {
1842       C->gvn_replace_by(callprojs.exobj, ex_oop);
1843     }
1844   }
1845 
1846   // Disconnect the call from the graph
1847   call->disconnect_inputs(NULL, C);
1848   C->gvn_replace_by(call, C->top());
1849 
1850   // Clean up any MergeMems that feed other MergeMems since the
1851   // optimizer doesn't like that.
1852   if (final_mem->is_MergeMem()) {
1853     Node_List wl;
1854     for (SimpleDUIterator i(final_mem); i.has_next(); i.next()) {
1855       Node* m = i.get();
1856       if (m->is_MergeMem() && !wl.contains(m)) {
1857         wl.push(m);
1858       }
1859     }
1860     while (wl.size()  > 0) {
1861       _gvn.transform(wl.pop());
1862     }
1863   }
1864 
1865   if (callprojs.fallthrough_catchproj != NULL && !final_ctl->is_top() && do_replaced_nodes) {
1866     replaced_nodes.apply(C, final_ctl);
1867   }
1868   if (!ex_ctl->is_top() && do_replaced_nodes) {
1869     replaced_nodes_exception.apply(C, ex_ctl);
1870   }
1871 }
1872 
1873 
1874 //------------------------------increment_counter------------------------------
1875 // for statistics: increment a VM counter by 1
1876 
1877 void GraphKit::increment_counter(address counter_addr) {
1878   Node* adr1 = makecon(TypeRawPtr::make(counter_addr));
1879   increment_counter(adr1);
1880 }
1881 
1882 void GraphKit::increment_counter(Node* counter_addr) {
1883   int adr_type = Compile::AliasIdxRaw;
1884   Node* ctrl = control();
1885   Node* cnt  = make_load(ctrl, counter_addr, TypeInt::INT, T_INT, adr_type, MemNode::unordered);
1886   Node* incr = _gvn.transform(new AddINode(cnt, _gvn.intcon(1)));
1887   store_to_memory(ctrl, counter_addr, incr, T_INT, adr_type, MemNode::unordered);
1888 }
1889 
1890 
1891 //------------------------------uncommon_trap----------------------------------
1892 // Bail out to the interpreter in mid-method.  Implemented by calling the
1893 // uncommon_trap blob.  This helper function inserts a runtime call with the
1894 // right debug info.
1895 void GraphKit::uncommon_trap(int trap_request,
1896                              ciKlass* klass, const char* comment,
1897                              bool must_throw,
1898                              bool keep_exact_action) {
1899   if (failing())  stop();
1900   if (stopped())  return; // trap reachable?
1901 
1902   // Note:  If ProfileTraps is true, and if a deopt. actually
1903   // occurs here, the runtime will make sure an MDO exists.  There is
1904   // no need to call method()->ensure_method_data() at this point.
1905 
1906   // Set the stack pointer to the right value for reexecution:
1907   set_sp(reexecute_sp());
1908 
1909 #ifdef ASSERT
1910   if (!must_throw) {
1911     // Make sure the stack has at least enough depth to execute
1912     // the current bytecode.
1913     int inputs, ignored_depth;
1914     if (compute_stack_effects(inputs, ignored_depth)) {
1915       assert(sp() >= inputs, "must have enough JVMS stack to execute %s: sp=%d, inputs=%d",
1916              Bytecodes::name(java_bc()), sp(), inputs);
1917     }
1918   }
1919 #endif
1920 
1921   Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(trap_request);
1922   Deoptimization::DeoptAction action = Deoptimization::trap_request_action(trap_request);
1923 
1924   switch (action) {
1925   case Deoptimization::Action_maybe_recompile:
1926   case Deoptimization::Action_reinterpret:
1927     // Temporary fix for 6529811 to allow virtual calls to be sure they
1928     // get the chance to go from mono->bi->mega
1929     if (!keep_exact_action &&
1930         Deoptimization::trap_request_index(trap_request) < 0 &&
1931         too_many_recompiles(reason)) {
1932       // This BCI is causing too many recompilations.
1933       if (C->log() != NULL) {
1934         C->log()->elem("observe that='trap_action_change' reason='%s' from='%s' to='none'",
1935                 Deoptimization::trap_reason_name(reason),
1936                 Deoptimization::trap_action_name(action));
1937       }
1938       action = Deoptimization::Action_none;
1939       trap_request = Deoptimization::make_trap_request(reason, action);
1940     } else {
1941       C->set_trap_can_recompile(true);
1942     }
1943     break;
1944   case Deoptimization::Action_make_not_entrant:
1945     C->set_trap_can_recompile(true);
1946     break;
1947 #ifdef ASSERT
1948   case Deoptimization::Action_none:
1949   case Deoptimization::Action_make_not_compilable:
1950     break;
1951   default:
1952     fatal("unknown action %d: %s", action, Deoptimization::trap_action_name(action));
1953     break;
1954 #endif
1955   }
1956 
1957   if (TraceOptoParse) {
1958     char buf[100];
1959     tty->print_cr("Uncommon trap %s at bci:%d",
1960                   Deoptimization::format_trap_request(buf, sizeof(buf),
1961                                                       trap_request), bci());
1962   }
1963 
1964   CompileLog* log = C->log();
1965   if (log != NULL) {
1966     int kid = (klass == NULL)? -1: log->identify(klass);
1967     log->begin_elem("uncommon_trap bci='%d'", bci());
1968     char buf[100];
1969     log->print(" %s", Deoptimization::format_trap_request(buf, sizeof(buf),
1970                                                           trap_request));
1971     if (kid >= 0)         log->print(" klass='%d'", kid);
1972     if (comment != NULL)  log->print(" comment='%s'", comment);
1973     log->end_elem();
1974   }
1975 
1976   // Make sure any guarding test views this path as very unlikely
1977   Node *i0 = control()->in(0);
1978   if (i0 != NULL && i0->is_If()) {        // Found a guarding if test?
1979     IfNode *iff = i0->as_If();
1980     float f = iff->_prob;   // Get prob
1981     if (control()->Opcode() == Op_IfTrue) {
1982       if (f > PROB_UNLIKELY_MAG(4))
1983         iff->_prob = PROB_MIN;
1984     } else {
1985       if (f < PROB_LIKELY_MAG(4))
1986         iff->_prob = PROB_MAX;
1987     }
1988   }
1989 
1990   // Clear out dead values from the debug info.
1991   kill_dead_locals();
1992 
1993   // Now insert the uncommon trap subroutine call
1994   address call_addr = SharedRuntime::uncommon_trap_blob()->entry_point();
1995   const TypePtr* no_memory_effects = NULL;
1996   // Pass the index of the class to be loaded
1997   Node* call = make_runtime_call(RC_NO_LEAF | RC_UNCOMMON |
1998                                  (must_throw ? RC_MUST_THROW : 0),
1999                                  OptoRuntime::uncommon_trap_Type(),
2000                                  call_addr, "uncommon_trap", no_memory_effects,
2001                                  intcon(trap_request));
2002   assert(call->as_CallStaticJava()->uncommon_trap_request() == trap_request,
2003          "must extract request correctly from the graph");
2004   assert(trap_request != 0, "zero value reserved by uncommon_trap_request");
2005 
2006   call->set_req(TypeFunc::ReturnAdr, returnadr());
2007   // The debug info is the only real input to this call.
2008 
2009   // Halt-and-catch fire here.  The above call should never return!
2010   HaltNode* halt = new HaltNode(control(), frameptr());
2011   _gvn.set_type_bottom(halt);
2012   root()->add_req(halt);
2013 
2014   stop_and_kill_map();
2015 }
2016 
2017 
2018 //--------------------------just_allocated_object------------------------------
2019 // Report the object that was just allocated.
2020 // It must be the case that there are no intervening safepoints.
2021 // We use this to determine if an object is so "fresh" that
2022 // it does not require card marks.
2023 Node* GraphKit::just_allocated_object(Node* current_control) {
2024   if (C->recent_alloc_ctl() == current_control)
2025     return C->recent_alloc_obj();
2026   return NULL;
2027 }
2028 
2029 
2030 void GraphKit::round_double_arguments(ciMethod* dest_method) {
2031   // (Note:  TypeFunc::make has a cache that makes this fast.)
2032   const TypeFunc* tf    = TypeFunc::make(dest_method);
2033   int             nargs = tf->domain_sig()->cnt() - TypeFunc::Parms;
2034   for (int j = 0; j < nargs; j++) {
2035     const Type *targ = tf->domain_sig()->field_at(j + TypeFunc::Parms);
2036     if( targ->basic_type() == T_DOUBLE ) {
2037       // If any parameters are doubles, they must be rounded before
2038       // the call, dstore_rounding does gvn.transform
2039       Node *arg = argument(j);
2040       arg = dstore_rounding(arg);
2041       set_argument(j, arg);
2042     }
2043   }
2044 }
2045 
2046 /**
2047  * Record profiling data exact_kls for Node n with the type system so
2048  * that it can propagate it (speculation)
2049  *
2050  * @param n          node that the type applies to
2051  * @param exact_kls  type from profiling
2052  * @param maybe_null did profiling see null?
2053  *
2054  * @return           node with improved type
2055  */
2056 Node* GraphKit::record_profile_for_speculation(Node* n, ciKlass* exact_kls, bool maybe_null) {
2057   const Type* current_type = _gvn.type(n);
2058   assert(UseTypeSpeculation, "type speculation must be on");
2059 
2060   const TypePtr* speculative = current_type->speculative();
2061 
2062   // Should the klass from the profile be recorded in the speculative type?
2063   if (current_type->would_improve_type(exact_kls, jvms()->depth())) {
2064     const TypeKlassPtr* tklass = TypeKlassPtr::make(exact_kls);
2065     const TypeOopPtr* xtype = tklass->as_instance_type();
2066     assert(xtype->klass_is_exact(), "Should be exact");
2067     // Any reason to believe n is not null (from this profiling or a previous one)?
2068     const TypePtr* ptr = (maybe_null && current_type->speculative_maybe_null()) ? TypePtr::BOTTOM : TypePtr::NOTNULL;
2069     // record the new speculative type's depth
2070     speculative = xtype->cast_to_ptr_type(ptr->ptr())->is_ptr();
2071     speculative = speculative->with_inline_depth(jvms()->depth());
2072   } else if (current_type->would_improve_ptr(maybe_null)) {
2073     // Profiling report that null was never seen so we can change the
2074     // speculative type to non null ptr.
2075     assert(!maybe_null, "nothing to improve");
2076     if (speculative == NULL) {
2077       speculative = TypePtr::NOTNULL;
2078     } else {
2079       const TypePtr* ptr = TypePtr::NOTNULL;
2080       speculative = speculative->cast_to_ptr_type(ptr->ptr())->is_ptr();
2081     }
2082   }
2083 
2084   if (speculative != current_type->speculative()) {
2085     // Build a type with a speculative type (what we think we know
2086     // about the type but will need a guard when we use it)
2087     const TypeOopPtr* spec_type = TypeOopPtr::make(TypePtr::BotPTR, Type::Offset::bottom, TypeOopPtr::InstanceBot, speculative);
2088     // We're changing the type, we need a new CheckCast node to carry
2089     // the new type. The new type depends on the control: what
2090     // profiling tells us is only valid from here as far as we can
2091     // tell.
2092     Node* cast = new CheckCastPPNode(control(), n, current_type->remove_speculative()->join_speculative(spec_type));
2093     cast = _gvn.transform(cast);
2094     replace_in_map(n, cast);
2095     n = cast;
2096   }
2097 
2098   return n;
2099 }
2100 
2101 /**
2102  * Record profiling data from receiver profiling at an invoke with the
2103  * type system so that it can propagate it (speculation)
2104  *
2105  * @param n  receiver node
2106  *
2107  * @return   node with improved type
2108  */
2109 Node* GraphKit::record_profiled_receiver_for_speculation(Node* n) {
2110   if (!UseTypeSpeculation) {
2111     return n;
2112   }
2113   ciKlass* exact_kls = profile_has_unique_klass();
2114   bool maybe_null = true;
2115   if (java_bc() == Bytecodes::_checkcast ||
2116       java_bc() == Bytecodes::_instanceof ||
2117       java_bc() == Bytecodes::_aastore) {
2118     ciProfileData* data = method()->method_data()->bci_to_data(bci());
2119     maybe_null = data == NULL ? true : data->as_BitData()->null_seen();
2120   }
2121   return record_profile_for_speculation(n, exact_kls, maybe_null);
2122 }
2123 
2124 /**
2125  * Record profiling data from argument profiling at an invoke with the
2126  * type system so that it can propagate it (speculation)
2127  *
2128  * @param dest_method  target method for the call
2129  * @param bc           what invoke bytecode is this?
2130  */
2131 void GraphKit::record_profiled_arguments_for_speculation(ciMethod* dest_method, Bytecodes::Code bc) {
2132   if (!UseTypeSpeculation) {
2133     return;
2134   }
2135   const TypeFunc* tf    = TypeFunc::make(dest_method);
2136   int             nargs = tf->domain_sig()->cnt() - TypeFunc::Parms;
2137   int skip = Bytecodes::has_receiver(bc) ? 1 : 0;
2138   for (int j = skip, i = 0; j < nargs && i < TypeProfileArgsLimit; j++) {
2139     const Type *targ = tf->domain_sig()->field_at(j + TypeFunc::Parms);
2140     if (targ->isa_oopptr() && !targ->isa_valuetypeptr()) {
2141       bool maybe_null = true;
2142       ciKlass* better_type = NULL;
2143       if (method()->argument_profiled_type(bci(), i, better_type, maybe_null)) {
2144         record_profile_for_speculation(argument(j), better_type, maybe_null);
2145       }
2146       i++;
2147     }
2148   }
2149 }
2150 
2151 /**
2152  * Record profiling data from parameter profiling at an invoke with
2153  * the type system so that it can propagate it (speculation)
2154  */
2155 void GraphKit::record_profiled_parameters_for_speculation() {
2156   if (!UseTypeSpeculation) {
2157     return;
2158   }
2159   for (int i = 0, j = 0; i < method()->arg_size() ; i++) {
2160     if (_gvn.type(local(i))->isa_oopptr()) {
2161       bool maybe_null = true;
2162       ciKlass* better_type = NULL;
2163       if (method()->parameter_profiled_type(j, better_type, maybe_null)) {
2164         record_profile_for_speculation(local(i), better_type, maybe_null);
2165       }
2166       j++;
2167     }
2168   }
2169 }
2170 
2171 /**
2172  * Record profiling data from return value profiling at an invoke with
2173  * the type system so that it can propagate it (speculation)
2174  */
2175 void GraphKit::record_profiled_return_for_speculation() {
2176   if (!UseTypeSpeculation) {
2177     return;
2178   }
2179   bool maybe_null = true;
2180   ciKlass* better_type = NULL;
2181   if (method()->return_profiled_type(bci(), better_type, maybe_null)) {
2182     // If profiling reports a single type for the return value,
2183     // feed it to the type system so it can propagate it as a
2184     // speculative type
2185     record_profile_for_speculation(stack(sp()-1), better_type, maybe_null);
2186   }
2187 }
2188 
2189 void GraphKit::round_double_result(ciMethod* dest_method) {
2190   // A non-strict method may return a double value which has an extended
2191   // exponent, but this must not be visible in a caller which is 'strict'
2192   // If a strict caller invokes a non-strict callee, round a double result
2193 
2194   BasicType result_type = dest_method->return_type()->basic_type();
2195   assert( method() != NULL, "must have caller context");
2196   if( result_type == T_DOUBLE && method()->is_strict() && !dest_method->is_strict() ) {
2197     // Destination method's return value is on top of stack
2198     // dstore_rounding() does gvn.transform
2199     Node *result = pop_pair();
2200     result = dstore_rounding(result);
2201     push_pair(result);
2202   }
2203 }
2204 
2205 // rounding for strict float precision conformance
2206 Node* GraphKit::precision_rounding(Node* n) {
2207   return UseStrictFP && _method->flags().is_strict()
2208     && UseSSE == 0 && Matcher::strict_fp_requires_explicit_rounding
2209     ? _gvn.transform( new RoundFloatNode(0, n) )
2210     : n;
2211 }
2212 
2213 // rounding for strict double precision conformance
2214 Node* GraphKit::dprecision_rounding(Node *n) {
2215   return UseStrictFP && _method->flags().is_strict()
2216     && UseSSE <= 1 && Matcher::strict_fp_requires_explicit_rounding
2217     ? _gvn.transform( new RoundDoubleNode(0, n) )
2218     : n;
2219 }
2220 
2221 // rounding for non-strict double stores
2222 Node* GraphKit::dstore_rounding(Node* n) {
2223   return Matcher::strict_fp_requires_explicit_rounding
2224     && UseSSE <= 1
2225     ? _gvn.transform( new RoundDoubleNode(0, n) )
2226     : n;
2227 }
2228 
2229 //=============================================================================
2230 // Generate a fast path/slow path idiom.  Graph looks like:
2231 // [foo] indicates that 'foo' is a parameter
2232 //
2233 //              [in]     NULL
2234 //                 \    /
2235 //                  CmpP
2236 //                  Bool ne
2237 //                   If
2238 //                  /  \
2239 //              True    False-<2>
2240 //              / |
2241 //             /  cast_not_null
2242 //           Load  |    |   ^
2243 //        [fast_test]   |   |
2244 // gvn to   opt_test    |   |
2245 //          /    \      |  <1>
2246 //      True     False  |
2247 //        |         \\  |
2248 //   [slow_call]     \[fast_result]
2249 //    Ctl   Val       \      \
2250 //     |               \      \
2251 //    Catch       <1>   \      \
2252 //   /    \        ^     \      \
2253 //  Ex    No_Ex    |      \      \
2254 //  |       \   \  |       \ <2>  \
2255 //  ...      \  [slow_res] |  |    \   [null_result]
2256 //            \         \--+--+---  |  |
2257 //             \           | /    \ | /
2258 //              --------Region     Phi
2259 //
2260 //=============================================================================
2261 // Code is structured as a series of driver functions all called 'do_XXX' that
2262 // call a set of helper functions.  Helper functions first, then drivers.
2263 
2264 //------------------------------null_check_oop---------------------------------
2265 // Null check oop.  Set null-path control into Region in slot 3.
2266 // Make a cast-not-nullness use the other not-null control.  Return cast.
2267 Node* GraphKit::null_check_oop(Node* value, Node* *null_control,
2268                                bool never_see_null,
2269                                bool safe_for_replace,
2270                                bool speculative) {
2271   // Initial NULL check taken path
2272   (*null_control) = top();
2273   Node* cast = null_check_common(value, T_OBJECT, false, null_control, speculative);
2274 
2275   // Generate uncommon_trap:
2276   if (never_see_null && (*null_control) != top()) {
2277     // If we see an unexpected null at a check-cast we record it and force a
2278     // recompile; the offending check-cast will be compiled to handle NULLs.
2279     // If we see more than one offending BCI, then all checkcasts in the
2280     // method will be compiled to handle NULLs.
2281     PreserveJVMState pjvms(this);
2282     set_control(*null_control);
2283     replace_in_map(value, null());
2284     Deoptimization::DeoptReason reason = Deoptimization::reason_null_check(speculative);
2285     uncommon_trap(reason,
2286                   Deoptimization::Action_make_not_entrant);
2287     (*null_control) = top();    // NULL path is dead
2288   }
2289   if ((*null_control) == top() && safe_for_replace) {
2290     replace_in_map(value, cast);
2291   }
2292 
2293   // Cast away null-ness on the result
2294   return cast;
2295 }
2296 
2297 //------------------------------opt_iff----------------------------------------
2298 // Optimize the fast-check IfNode.  Set the fast-path region slot 2.
2299 // Return slow-path control.
2300 Node* GraphKit::opt_iff(Node* region, Node* iff) {
2301   IfNode *opt_iff = _gvn.transform(iff)->as_If();
2302 
2303   // Fast path taken; set region slot 2
2304   Node *fast_taken = _gvn.transform( new IfFalseNode(opt_iff) );
2305   region->init_req(2,fast_taken); // Capture fast-control
2306 
2307   // Fast path not-taken, i.e. slow path
2308   Node *slow_taken = _gvn.transform( new IfTrueNode(opt_iff) );
2309   return slow_taken;
2310 }
2311 
2312 //-----------------------------make_runtime_call-------------------------------
2313 Node* GraphKit::make_runtime_call(int flags,
2314                                   const TypeFunc* call_type, address call_addr,
2315                                   const char* call_name,
2316                                   const TypePtr* adr_type,
2317                                   // The following parms are all optional.
2318                                   // The first NULL ends the list.
2319                                   Node* parm0, Node* parm1,
2320                                   Node* parm2, Node* parm3,
2321                                   Node* parm4, Node* parm5,
2322                                   Node* parm6, Node* parm7) {
2323   // Slow-path call
2324   bool is_leaf = !(flags & RC_NO_LEAF);
2325   bool has_io  = (!is_leaf && !(flags & RC_NO_IO));
2326   if (call_name == NULL) {
2327     assert(!is_leaf, "must supply name for leaf");
2328     call_name = OptoRuntime::stub_name(call_addr);
2329   }
2330   CallNode* call;
2331   if (!is_leaf) {
2332     call = new CallStaticJavaNode(call_type, call_addr, call_name,
2333                                            bci(), adr_type);
2334   } else if (flags & RC_NO_FP) {
2335     call = new CallLeafNoFPNode(call_type, call_addr, call_name, adr_type);
2336   } else {
2337     call = new CallLeafNode(call_type, call_addr, call_name, adr_type);
2338   }
2339 
2340   // The following is similar to set_edges_for_java_call,
2341   // except that the memory effects of the call are restricted to AliasIdxRaw.
2342 
2343   // Slow path call has no side-effects, uses few values
2344   bool wide_in  = !(flags & RC_NARROW_MEM);
2345   bool wide_out = (C->get_alias_index(adr_type) == Compile::AliasIdxBot);
2346 
2347   Node* prev_mem = NULL;
2348   if (wide_in) {
2349     prev_mem = set_predefined_input_for_runtime_call(call);
2350   } else {
2351     assert(!wide_out, "narrow in => narrow out");
2352     Node* narrow_mem = memory(adr_type);
2353     prev_mem = reset_memory();
2354     map()->set_memory(narrow_mem);
2355     set_predefined_input_for_runtime_call(call);
2356   }
2357 
2358   // Hook each parm in order.  Stop looking at the first NULL.
2359   if (parm0 != NULL) { call->init_req(TypeFunc::Parms+0, parm0);
2360   if (parm1 != NULL) { call->init_req(TypeFunc::Parms+1, parm1);
2361   if (parm2 != NULL) { call->init_req(TypeFunc::Parms+2, parm2);
2362   if (parm3 != NULL) { call->init_req(TypeFunc::Parms+3, parm3);
2363   if (parm4 != NULL) { call->init_req(TypeFunc::Parms+4, parm4);
2364   if (parm5 != NULL) { call->init_req(TypeFunc::Parms+5, parm5);
2365   if (parm6 != NULL) { call->init_req(TypeFunc::Parms+6, parm6);
2366   if (parm7 != NULL) { call->init_req(TypeFunc::Parms+7, parm7);
2367     /* close each nested if ===> */  } } } } } } } }
2368   assert(call->in(call->req()-1) != NULL, "must initialize all parms");
2369 
2370   if (!is_leaf) {
2371     // Non-leaves can block and take safepoints:
2372     add_safepoint_edges(call, ((flags & RC_MUST_THROW) != 0));
2373   }
2374   // Non-leaves can throw exceptions:
2375   if (has_io) {
2376     call->set_req(TypeFunc::I_O, i_o());
2377   }
2378 
2379   if (flags & RC_UNCOMMON) {
2380     // Set the count to a tiny probability.  Cf. Estimate_Block_Frequency.
2381     // (An "if" probability corresponds roughly to an unconditional count.
2382     // Sort of.)
2383     call->set_cnt(PROB_UNLIKELY_MAG(4));
2384   }
2385 
2386   Node* c = _gvn.transform(call);
2387   assert(c == call, "cannot disappear");
2388 
2389   if (wide_out) {
2390     // Slow path call has full side-effects.
2391     set_predefined_output_for_runtime_call(call);
2392   } else {
2393     // Slow path call has few side-effects, and/or sets few values.
2394     set_predefined_output_for_runtime_call(call, prev_mem, adr_type);
2395   }
2396 
2397   if (has_io) {
2398     set_i_o(_gvn.transform(new ProjNode(call, TypeFunc::I_O)));
2399   }
2400   return call;
2401 
2402 }
2403 
2404 //------------------------------merge_memory-----------------------------------
2405 // Merge memory from one path into the current memory state.
2406 void GraphKit::merge_memory(Node* new_mem, Node* region, int new_path) {
2407   for (MergeMemStream mms(merged_memory(), new_mem->as_MergeMem()); mms.next_non_empty2(); ) {
2408     Node* old_slice = mms.force_memory();
2409     Node* new_slice = mms.memory2();
2410     if (old_slice != new_slice) {
2411       PhiNode* phi;
2412       if (old_slice->is_Phi() && old_slice->as_Phi()->region() == region) {
2413         if (mms.is_empty()) {
2414           // clone base memory Phi's inputs for this memory slice
2415           assert(old_slice == mms.base_memory(), "sanity");
2416           phi = PhiNode::make(region, NULL, Type::MEMORY, mms.adr_type(C));
2417           _gvn.set_type(phi, Type::MEMORY);
2418           for (uint i = 1; i < phi->req(); i++) {
2419             phi->init_req(i, old_slice->in(i));
2420           }
2421         } else {
2422           phi = old_slice->as_Phi(); // Phi was generated already
2423         }
2424       } else {
2425         phi = PhiNode::make(region, old_slice, Type::MEMORY, mms.adr_type(C));
2426         _gvn.set_type(phi, Type::MEMORY);
2427       }
2428       phi->set_req(new_path, new_slice);
2429       mms.set_memory(phi);
2430     }
2431   }
2432 }
2433 
2434 //------------------------------make_slow_call_ex------------------------------
2435 // Make the exception handler hookups for the slow call
2436 void GraphKit::make_slow_call_ex(Node* call, ciInstanceKlass* ex_klass, bool separate_io_proj, bool deoptimize) {
2437   if (stopped())  return;
2438 
2439   // Make a catch node with just two handlers:  fall-through and catch-all
2440   Node* i_o  = _gvn.transform( new ProjNode(call, TypeFunc::I_O, separate_io_proj) );
2441   Node* catc = _gvn.transform( new CatchNode(control(), i_o, 2) );
2442   Node* norm = _gvn.transform( new CatchProjNode(catc, CatchProjNode::fall_through_index, CatchProjNode::no_handler_bci) );
2443   Node* excp = _gvn.transform( new CatchProjNode(catc, CatchProjNode::catch_all_index,    CatchProjNode::no_handler_bci) );
2444 
2445   { PreserveJVMState pjvms(this);
2446     set_control(excp);
2447     set_i_o(i_o);
2448 
2449     if (excp != top()) {
2450       if (deoptimize) {
2451         // Deoptimize if an exception is caught. Don't construct exception state in this case.
2452         uncommon_trap(Deoptimization::Reason_unhandled,
2453                       Deoptimization::Action_none);
2454       } else {
2455         // Create an exception state also.
2456         // Use an exact type if the caller has specified a specific exception.
2457         const Type* ex_type = TypeOopPtr::make_from_klass_unique(ex_klass)->cast_to_ptr_type(TypePtr::NotNull);
2458         Node*       ex_oop  = new CreateExNode(ex_type, control(), i_o);
2459         add_exception_state(make_exception_state(_gvn.transform(ex_oop)));
2460       }
2461     }
2462   }
2463 
2464   // Get the no-exception control from the CatchNode.
2465   set_control(norm);
2466 }
2467 
2468 static IfNode* gen_subtype_check_compare(Node* ctrl, Node* in1, Node* in2, BoolTest::mask test, float p, PhaseGVN* gvn, BasicType bt) {
2469   Node* cmp = NULL;
2470   switch(bt) {
2471   case T_INT: cmp = new CmpINode(in1, in2); break;
2472   case T_ADDRESS: cmp = new CmpPNode(in1, in2); break;
2473   default: fatal("unexpected comparison type %s", type2name(bt));
2474   }
2475   gvn->transform(cmp);
2476   Node* bol = gvn->transform(new BoolNode(cmp, test));
2477   IfNode* iff = new IfNode(ctrl, bol, p, COUNT_UNKNOWN);
2478   gvn->transform(iff);
2479   if (!bol->is_Con()) gvn->record_for_igvn(iff);
2480   return iff;
2481 }
2482 
2483 
2484 //-------------------------------gen_subtype_check-----------------------------
2485 // Generate a subtyping check.  Takes as input the subtype and supertype.
2486 // Returns 2 values: sets the default control() to the true path and returns
2487 // the false path.  Only reads invariant memory; sets no (visible) memory.
2488 // The PartialSubtypeCheckNode sets the hidden 1-word cache in the encoding
2489 // but that's not exposed to the optimizer.  This call also doesn't take in an
2490 // Object; if you wish to check an Object you need to load the Object's class
2491 // prior to coming here.
2492 Node* Phase::gen_subtype_check(Node* subklass, Node* superklass, Node** ctrl, MergeMemNode* mem, PhaseGVN* gvn) {
2493   Compile* C = gvn->C;
2494 
2495   if ((*ctrl)->is_top()) {
2496     return C->top();
2497   }
2498 
2499   // Fast check for identical types, perhaps identical constants.
2500   // The types can even be identical non-constants, in cases
2501   // involving Array.newInstance, Object.clone, etc.
2502   if (subklass == superklass)
2503     return C->top();             // false path is dead; no test needed.
2504 
2505   if (gvn->type(superklass)->singleton()) {
2506     ciKlass* superk = gvn->type(superklass)->is_klassptr()->klass();
2507     ciKlass* subk   = gvn->type(subklass)->is_klassptr()->klass();
2508 
2509     // In the common case of an exact superklass, try to fold up the
2510     // test before generating code.  You may ask, why not just generate
2511     // the code and then let it fold up?  The answer is that the generated
2512     // code will necessarily include null checks, which do not always
2513     // completely fold away.  If they are also needless, then they turn
2514     // into a performance loss.  Example:
2515     //    Foo[] fa = blah(); Foo x = fa[0]; fa[1] = x;
2516     // Here, the type of 'fa' is often exact, so the store check
2517     // of fa[1]=x will fold up, without testing the nullness of x.
2518     switch (C->static_subtype_check(superk, subk)) {
2519     case Compile::SSC_always_false:
2520       {
2521         Node* always_fail = *ctrl;
2522         *ctrl = gvn->C->top();
2523         return always_fail;
2524       }
2525     case Compile::SSC_always_true:
2526       return C->top();
2527     case Compile::SSC_easy_test:
2528       {
2529         // Just do a direct pointer compare and be done.
2530         IfNode* iff = gen_subtype_check_compare(*ctrl, subklass, superklass, BoolTest::eq, PROB_STATIC_FREQUENT, gvn, T_ADDRESS);
2531         *ctrl = gvn->transform(new IfTrueNode(iff));
2532         return gvn->transform(new IfFalseNode(iff));
2533       }
2534     case Compile::SSC_full_test:
2535       break;
2536     default:
2537       ShouldNotReachHere();
2538     }
2539   }
2540 
2541   // %%% Possible further optimization:  Even if the superklass is not exact,
2542   // if the subklass is the unique subtype of the superklass, the check
2543   // will always succeed.  We could leave a dependency behind to ensure this.
2544 
2545   // First load the super-klass's check-offset
2546   Node *p1 = gvn->transform(new AddPNode(superklass, superklass, gvn->MakeConX(in_bytes(Klass::super_check_offset_offset()))));
2547   Node* m = mem->memory_at(C->get_alias_index(gvn->type(p1)->is_ptr()));
2548   Node *chk_off = gvn->transform(new LoadINode(NULL, m, p1, gvn->type(p1)->is_ptr(), TypeInt::INT, MemNode::unordered));
2549   int cacheoff_con = in_bytes(Klass::secondary_super_cache_offset());
2550   bool might_be_cache = (gvn->find_int_con(chk_off, cacheoff_con) == cacheoff_con);
2551 
2552   // Load from the sub-klass's super-class display list, or a 1-word cache of
2553   // the secondary superclass list, or a failing value with a sentinel offset
2554   // if the super-klass is an interface or exceptionally deep in the Java
2555   // hierarchy and we have to scan the secondary superclass list the hard way.
2556   // Worst-case type is a little odd: NULL is allowed as a result (usually
2557   // klass loads can never produce a NULL).
2558   Node *chk_off_X = chk_off;
2559 #ifdef _LP64
2560   chk_off_X = gvn->transform(new ConvI2LNode(chk_off_X));
2561 #endif
2562   Node *p2 = gvn->transform(new AddPNode(subklass,subklass,chk_off_X));
2563   // For some types like interfaces the following loadKlass is from a 1-word
2564   // cache which is mutable so can't use immutable memory.  Other
2565   // types load from the super-class display table which is immutable.
2566   m = mem->memory_at(C->get_alias_index(gvn->type(p2)->is_ptr()));
2567   Node *kmem = might_be_cache ? m : C->immutable_memory();
2568   Node *nkls = gvn->transform(LoadKlassNode::make(*gvn, NULL, kmem, p2, gvn->type(p2)->is_ptr(), TypeKlassPtr::BOTTOM));
2569 
2570   // Compile speed common case: ARE a subtype and we canNOT fail
2571   if( superklass == nkls )
2572     return C->top();             // false path is dead; no test needed.
2573 
2574   // See if we get an immediate positive hit.  Happens roughly 83% of the
2575   // time.  Test to see if the value loaded just previously from the subklass
2576   // is exactly the superklass.
2577   IfNode *iff1 = gen_subtype_check_compare(*ctrl, superklass, nkls, BoolTest::eq, PROB_LIKELY(0.83f), gvn, T_ADDRESS);
2578   Node *iftrue1 = gvn->transform( new IfTrueNode (iff1));
2579   *ctrl = gvn->transform(new IfFalseNode(iff1));
2580 
2581   // Compile speed common case: Check for being deterministic right now.  If
2582   // chk_off is a constant and not equal to cacheoff then we are NOT a
2583   // subklass.  In this case we need exactly the 1 test above and we can
2584   // return those results immediately.
2585   if (!might_be_cache) {
2586     Node* not_subtype_ctrl = *ctrl;
2587     *ctrl = iftrue1; // We need exactly the 1 test above
2588     return not_subtype_ctrl;
2589   }
2590 
2591   // Gather the various success & failures here
2592   RegionNode *r_ok_subtype = new RegionNode(4);
2593   gvn->record_for_igvn(r_ok_subtype);
2594   RegionNode *r_not_subtype = new RegionNode(3);
2595   gvn->record_for_igvn(r_not_subtype);
2596 
2597   r_ok_subtype->init_req(1, iftrue1);
2598 
2599   // Check for immediate negative hit.  Happens roughly 11% of the time (which
2600   // is roughly 63% of the remaining cases).  Test to see if the loaded
2601   // check-offset points into the subklass display list or the 1-element
2602   // cache.  If it points to the display (and NOT the cache) and the display
2603   // missed then it's not a subtype.
2604   Node *cacheoff = gvn->intcon(cacheoff_con);
2605   IfNode *iff2 = gen_subtype_check_compare(*ctrl, chk_off, cacheoff, BoolTest::ne, PROB_LIKELY(0.63f), gvn, T_INT);
2606   r_not_subtype->init_req(1, gvn->transform(new IfTrueNode (iff2)));
2607   *ctrl = gvn->transform(new IfFalseNode(iff2));
2608 
2609   // Check for self.  Very rare to get here, but it is taken 1/3 the time.
2610   // No performance impact (too rare) but allows sharing of secondary arrays
2611   // which has some footprint reduction.
2612   IfNode *iff3 = gen_subtype_check_compare(*ctrl, subklass, superklass, BoolTest::eq, PROB_LIKELY(0.36f), gvn, T_ADDRESS);
2613   r_ok_subtype->init_req(2, gvn->transform(new IfTrueNode(iff3)));
2614   *ctrl = gvn->transform(new IfFalseNode(iff3));
2615 
2616   // -- Roads not taken here: --
2617   // We could also have chosen to perform the self-check at the beginning
2618   // of this code sequence, as the assembler does.  This would not pay off
2619   // the same way, since the optimizer, unlike the assembler, can perform
2620   // static type analysis to fold away many successful self-checks.
2621   // Non-foldable self checks work better here in second position, because
2622   // the initial primary superclass check subsumes a self-check for most
2623   // types.  An exception would be a secondary type like array-of-interface,
2624   // which does not appear in its own primary supertype display.
2625   // Finally, we could have chosen to move the self-check into the
2626   // PartialSubtypeCheckNode, and from there out-of-line in a platform
2627   // dependent manner.  But it is worthwhile to have the check here,
2628   // where it can be perhaps be optimized.  The cost in code space is
2629   // small (register compare, branch).
2630 
2631   // Now do a linear scan of the secondary super-klass array.  Again, no real
2632   // performance impact (too rare) but it's gotta be done.
2633   // Since the code is rarely used, there is no penalty for moving it
2634   // out of line, and it can only improve I-cache density.
2635   // The decision to inline or out-of-line this final check is platform
2636   // dependent, and is found in the AD file definition of PartialSubtypeCheck.
2637   Node* psc = gvn->transform(
2638     new PartialSubtypeCheckNode(*ctrl, subklass, superklass));
2639 
2640   IfNode *iff4 = gen_subtype_check_compare(*ctrl, psc, gvn->zerocon(T_OBJECT), BoolTest::ne, PROB_FAIR, gvn, T_ADDRESS);
2641   r_not_subtype->init_req(2, gvn->transform(new IfTrueNode (iff4)));
2642   r_ok_subtype ->init_req(3, gvn->transform(new IfFalseNode(iff4)));
2643 
2644   // Return false path; set default control to true path.
2645   *ctrl = gvn->transform(r_ok_subtype);
2646   return gvn->transform(r_not_subtype);
2647 }
2648 
2649 // Profile-driven exact type check:
2650 Node* GraphKit::type_check_receiver(Node* receiver, ciKlass* klass,
2651                                     float prob,
2652                                     Node* *casted_receiver) {
2653   const TypeKlassPtr* tklass = TypeKlassPtr::make(klass);
2654   Node* recv_klass = load_object_klass(receiver);
2655   Node* fail = type_check(recv_klass, tklass, prob);
2656   const TypeOopPtr* recv_xtype = tklass->as_instance_type();
2657   assert(recv_xtype->klass_is_exact(), "");
2658 
2659   // Subsume downstream occurrences of receiver with a cast to
2660   // recv_xtype, since now we know what the type will be.
2661   Node* cast = new CheckCastPPNode(control(), receiver, recv_xtype);
2662   (*casted_receiver) = _gvn.transform(cast);
2663   // (User must make the replace_in_map call.)
2664 
2665   return fail;
2666 }
2667 
2668 Node* GraphKit::type_check(Node* recv_klass, const TypeKlassPtr* tklass,
2669                            float prob) {
2670   //const TypeKlassPtr* tklass = TypeKlassPtr::make(klass);
2671   Node* want_klass = makecon(tklass);
2672   Node* cmp = _gvn.transform( new CmpPNode(recv_klass, want_klass));
2673   Node* bol = _gvn.transform( new BoolNode(cmp, BoolTest::eq) );
2674   IfNode* iff = create_and_xform_if(control(), bol, prob, COUNT_UNKNOWN);
2675   set_control(  _gvn.transform( new IfTrueNode (iff)));
2676   Node* fail = _gvn.transform( new IfFalseNode(iff));
2677   return fail;
2678 }
2679 
2680 
2681 //------------------------------seems_never_null-------------------------------
2682 // Use null_seen information if it is available from the profile.
2683 // If we see an unexpected null at a type check we record it and force a
2684 // recompile; the offending check will be recompiled to handle NULLs.
2685 // If we see several offending BCIs, then all checks in the
2686 // method will be recompiled.
2687 bool GraphKit::seems_never_null(Node* obj, ciProfileData* data, bool& speculating) {
2688   speculating = !_gvn.type(obj)->speculative_maybe_null();
2689   Deoptimization::DeoptReason reason = Deoptimization::reason_null_check(speculating);
2690   if (UncommonNullCast               // Cutout for this technique
2691       && obj != null()               // And not the -Xcomp stupid case?
2692       && !too_many_traps(reason)
2693       ) {
2694     if (speculating) {
2695       return true;
2696     }
2697     if (data == NULL)
2698       // Edge case:  no mature data.  Be optimistic here.
2699       return true;
2700     // If the profile has not seen a null, assume it won't happen.
2701     assert(java_bc() == Bytecodes::_checkcast ||
2702            java_bc() == Bytecodes::_instanceof ||
2703            java_bc() == Bytecodes::_aastore, "MDO must collect null_seen bit here");
2704     return !data->as_BitData()->null_seen();
2705   }
2706   speculating = false;
2707   return false;
2708 }
2709 
2710 //------------------------maybe_cast_profiled_receiver-------------------------
2711 // If the profile has seen exactly one type, narrow to exactly that type.
2712 // Subsequent type checks will always fold up.
2713 Node* GraphKit::maybe_cast_profiled_receiver(Node* not_null_obj,
2714                                              ciKlass* require_klass,
2715                                              ciKlass* spec_klass,
2716                                              bool safe_for_replace) {
2717   if (!UseTypeProfile || !TypeProfileCasts) return NULL;
2718 
2719   Deoptimization::DeoptReason reason = Deoptimization::reason_class_check(spec_klass != NULL);
2720 
2721   // Make sure we haven't already deoptimized from this tactic.
2722   if (too_many_traps(reason) || too_many_recompiles(reason))
2723     return NULL;
2724 
2725   // (No, this isn't a call, but it's enough like a virtual call
2726   // to use the same ciMethod accessor to get the profile info...)
2727   // If we have a speculative type use it instead of profiling (which
2728   // may not help us)
2729   ciKlass* exact_kls = spec_klass == NULL ? profile_has_unique_klass() : spec_klass;
2730   if (exact_kls != NULL) {// no cast failures here
2731     if (require_klass == NULL ||
2732         C->static_subtype_check(require_klass, exact_kls) == Compile::SSC_always_true) {
2733       // If we narrow the type to match what the type profile sees or
2734       // the speculative type, we can then remove the rest of the
2735       // cast.
2736       // This is a win, even if the exact_kls is very specific,
2737       // because downstream operations, such as method calls,
2738       // will often benefit from the sharper type.
2739       Node* exact_obj = not_null_obj; // will get updated in place...
2740       Node* slow_ctl  = type_check_receiver(exact_obj, exact_kls, 1.0,
2741                                             &exact_obj);
2742       { PreserveJVMState pjvms(this);
2743         set_control(slow_ctl);
2744         uncommon_trap_exact(reason, Deoptimization::Action_maybe_recompile);
2745       }
2746       if (safe_for_replace) {
2747         replace_in_map(not_null_obj, exact_obj);
2748       }
2749       return exact_obj;
2750     }
2751     // assert(ssc == Compile::SSC_always_true)... except maybe the profile lied to us.
2752   }
2753 
2754   return NULL;
2755 }
2756 
2757 /**
2758  * Cast obj to type and emit guard unless we had too many traps here
2759  * already
2760  *
2761  * @param obj       node being casted
2762  * @param type      type to cast the node to
2763  * @param not_null  true if we know node cannot be null
2764  */
2765 Node* GraphKit::maybe_cast_profiled_obj(Node* obj,
2766                                         ciKlass* type,
2767                                         bool not_null) {
2768   if (stopped()) {
2769     return obj;
2770   }
2771 
2772   // type == NULL if profiling tells us this object is always null
2773   if (type != NULL) {
2774     Deoptimization::DeoptReason class_reason = Deoptimization::Reason_speculate_class_check;
2775     Deoptimization::DeoptReason null_reason = Deoptimization::Reason_speculate_null_check;
2776 
2777     if (!too_many_traps(null_reason) && !too_many_recompiles(null_reason) &&
2778         !too_many_traps(class_reason) &&
2779         !too_many_recompiles(class_reason)) {
2780       Node* not_null_obj = NULL;
2781       // not_null is true if we know the object is not null and
2782       // there's no need for a null check
2783       if (!not_null) {
2784         Node* null_ctl = top();
2785         not_null_obj = null_check_oop(obj, &null_ctl, true, true, true);
2786         assert(null_ctl->is_top(), "no null control here");
2787       } else {
2788         not_null_obj = obj;
2789       }
2790 
2791       Node* exact_obj = not_null_obj;
2792       ciKlass* exact_kls = type;
2793       Node* slow_ctl  = type_check_receiver(exact_obj, exact_kls, 1.0,
2794                                             &exact_obj);
2795       {
2796         PreserveJVMState pjvms(this);
2797         set_control(slow_ctl);
2798         uncommon_trap_exact(class_reason, Deoptimization::Action_maybe_recompile);
2799       }
2800       replace_in_map(not_null_obj, exact_obj);
2801       obj = exact_obj;
2802     }
2803   } else {
2804     if (!too_many_traps(Deoptimization::Reason_null_assert) &&
2805         !too_many_recompiles(Deoptimization::Reason_null_assert)) {
2806       Node* exact_obj = null_assert(obj);
2807       replace_in_map(obj, exact_obj);
2808       obj = exact_obj;
2809     }
2810   }
2811   return obj;
2812 }
2813 
2814 //-------------------------------gen_instanceof--------------------------------
2815 // Generate an instance-of idiom.  Used by both the instance-of bytecode
2816 // and the reflective instance-of call.
2817 Node* GraphKit::gen_instanceof(Node* obj, Node* superklass, bool safe_for_replace) {
2818   kill_dead_locals();           // Benefit all the uncommon traps
2819   assert( !stopped(), "dead parse path should be checked in callers" );
2820   assert(!TypePtr::NULL_PTR->higher_equal(_gvn.type(superklass)->is_klassptr()),
2821          "must check for not-null not-dead klass in callers");
2822 
2823   // Make the merge point
2824   enum { _obj_path = 1, _fail_path, _null_path, PATH_LIMIT };
2825   RegionNode* region = new RegionNode(PATH_LIMIT);
2826   Node*       phi    = new PhiNode(region, TypeInt::BOOL);
2827   C->set_has_split_ifs(true); // Has chance for split-if optimization
2828 
2829   ciProfileData* data = NULL;
2830   if (java_bc() == Bytecodes::_instanceof) {  // Only for the bytecode
2831     data = method()->method_data()->bci_to_data(bci());
2832   }
2833   bool speculative_not_null = false;
2834   bool never_see_null = (ProfileDynamicTypes  // aggressive use of profile
2835                          && seems_never_null(obj, data, speculative_not_null));
2836 
2837   // Null check; get casted pointer; set region slot 3
2838   Node* null_ctl = top();
2839   Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null, safe_for_replace, speculative_not_null);
2840 
2841   // If not_null_obj is dead, only null-path is taken
2842   if (stopped()) {              // Doing instance-of on a NULL?
2843     set_control(null_ctl);
2844     return intcon(0);
2845   }
2846   region->init_req(_null_path, null_ctl);
2847   phi   ->init_req(_null_path, intcon(0)); // Set null path value
2848   if (null_ctl == top()) {
2849     // Do this eagerly, so that pattern matches like is_diamond_phi
2850     // will work even during parsing.
2851     assert(_null_path == PATH_LIMIT-1, "delete last");
2852     region->del_req(_null_path);
2853     phi   ->del_req(_null_path);
2854   }
2855 
2856   // Do we know the type check always succeed?
2857   bool known_statically = false;
2858   if (_gvn.type(superklass)->singleton()) {
2859     ciKlass* superk = _gvn.type(superklass)->is_klassptr()->klass();
2860     ciKlass* subk = _gvn.type(obj)->is_oopptr()->klass();
2861     if (subk != NULL && subk->is_loaded()) {
2862       int static_res = C->static_subtype_check(superk, subk);
2863       known_statically = (static_res == Compile::SSC_always_true || static_res == Compile::SSC_always_false);
2864     }
2865   }
2866 
2867   if (known_statically && UseTypeSpeculation) {
2868     // If we know the type check always succeeds then we don't use the
2869     // profiling data at this bytecode. Don't lose it, feed it to the
2870     // type system as a speculative type.
2871     not_null_obj = record_profiled_receiver_for_speculation(not_null_obj);
2872   } else {
2873     const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
2874     // We may not have profiling here or it may not help us. If we
2875     // have a speculative type use it to perform an exact cast.
2876     ciKlass* spec_obj_type = obj_type->speculative_type();
2877     if (spec_obj_type != NULL || (ProfileDynamicTypes && data != NULL)) {
2878       Node* cast_obj = maybe_cast_profiled_receiver(not_null_obj, NULL, spec_obj_type, safe_for_replace);
2879       if (stopped()) {            // Profile disagrees with this path.
2880         set_control(null_ctl);    // Null is the only remaining possibility.
2881         return intcon(0);
2882       }
2883       if (cast_obj != NULL) {
2884         not_null_obj = cast_obj;
2885       }
2886     }
2887   }
2888 
2889   // Load the object's klass
2890   Node* obj_klass = load_object_klass(not_null_obj);
2891 
2892   // Generate the subtype check
2893   Node* not_subtype_ctrl = gen_subtype_check(obj_klass, superklass);
2894 
2895   // Plug in the success path to the general merge in slot 1.
2896   region->init_req(_obj_path, control());
2897   phi   ->init_req(_obj_path, intcon(1));
2898 
2899   // Plug in the failing path to the general merge in slot 2.
2900   region->init_req(_fail_path, not_subtype_ctrl);
2901   phi   ->init_req(_fail_path, intcon(0));
2902 
2903   // Return final merged results
2904   set_control( _gvn.transform(region) );
2905   record_for_igvn(region);
2906   return _gvn.transform(phi);
2907 }
2908 
2909 //-------------------------------gen_checkcast---------------------------------
2910 // Generate a checkcast idiom.  Used by both the checkcast bytecode and the
2911 // array store bytecode.  Stack must be as-if BEFORE doing the bytecode so the
2912 // uncommon-trap paths work.  Adjust stack after this call.
2913 // If failure_control is supplied and not null, it is filled in with
2914 // the control edge for the cast failure.  Otherwise, an appropriate
2915 // uncommon trap or exception is thrown.
2916 Node* GraphKit::gen_checkcast(Node *obj, Node* superklass,
2917                               Node* *failure_control) {
2918   kill_dead_locals();           // Benefit all the uncommon traps
2919   const TypeKlassPtr *tk = _gvn.type(superklass)->is_klassptr();
2920   assert(tk->is_loaded(), "must be loaded");
2921   const Type *toop = TypeOopPtr::make_from_klass(tk->klass());
2922 
2923   // Fast cutout:  Check the case that the cast is vacuously true.
2924   // This detects the common cases where the test will short-circuit
2925   // away completely.  We do this before we perform the null check,
2926   // because if the test is going to turn into zero code, we don't
2927   // want a residual null check left around.  (Causes a slowdown,
2928   // for example, in some objArray manipulations, such as a[i]=a[j].)
2929   if (tk->singleton()) {
2930     const TypeOopPtr* objtp = _gvn.type(obj)->isa_oopptr();
2931     if (objtp != NULL && objtp->klass() != NULL) {
2932       switch (C->static_subtype_check(tk->klass(), objtp->klass())) {
2933       case Compile::SSC_always_true:
2934         // If we know the type check always succeed then we don't use
2935         // the profiling data at this bytecode. Don't lose it, feed it
2936         // to the type system as a speculative type.
2937         return record_profiled_receiver_for_speculation(obj);
2938       case Compile::SSC_always_false:
2939         // It needs a null check because a null will *pass* the cast check.
2940         // A non-null value will always produce an exception.
2941         return null_assert(obj);
2942       }
2943     }
2944   }
2945 
2946   ciProfileData* data = NULL;
2947   bool safe_for_replace = false;
2948   if (failure_control == NULL) {        // use MDO in regular case only
2949     assert(java_bc() == Bytecodes::_aastore ||
2950            java_bc() == Bytecodes::_checkcast,
2951            "interpreter profiles type checks only for these BCs");
2952     data = method()->method_data()->bci_to_data(bci());
2953     safe_for_replace = true;
2954   }
2955 
2956   // Make the merge point
2957   enum { _obj_path = 1, _null_path, PATH_LIMIT };
2958   RegionNode* region = new RegionNode(PATH_LIMIT);
2959   Node*       phi    = new PhiNode(region, toop);
2960   C->set_has_split_ifs(true); // Has chance for split-if optimization
2961 
2962   // Use null-cast information if it is available
2963   bool speculative_not_null = false;
2964   bool never_see_null = ((failure_control == NULL)  // regular case only
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 null();
2975   }
2976   region->init_req(_null_path, null_ctl);
2977   phi   ->init_req(_null_path, null());  // 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   Node* cast_obj = NULL;
2987   if (tk->klass_is_exact()) {
2988     // The following optimization tries to statically cast the speculative type of the object
2989     // (for example obtained during profiling) to the type of the superklass and then do a
2990     // dynamic check that the type of the object is what we expect. To work correctly
2991     // for checkcast and aastore the type of superklass should be exact.
2992     const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
2993     // We may not have profiling here or it may not help us. If we have
2994     // a speculative type use it to perform an exact cast.
2995     ciKlass* spec_obj_type = obj_type->speculative_type();
2996     if (spec_obj_type != NULL || data != NULL) {
2997       cast_obj = maybe_cast_profiled_receiver(not_null_obj, tk->klass(), spec_obj_type, safe_for_replace);
2998       if (cast_obj != NULL) {
2999         if (failure_control != NULL) // failure is now impossible
3000           (*failure_control) = top();
3001         // adjust the type of the phi to the exact klass:
3002         phi->raise_bottom_type(_gvn.type(cast_obj)->meet_speculative(TypePtr::NULL_PTR));
3003       }
3004     }
3005   }
3006 
3007   if (cast_obj == NULL) {
3008     // Load the object's klass
3009     Node* obj_klass = load_object_klass(not_null_obj);
3010 
3011     // Generate the subtype check
3012     Node* not_subtype_ctrl = gen_subtype_check( obj_klass, superklass );
3013 
3014     // Plug in success path into the merge
3015     cast_obj = _gvn.transform(new CheckCastPPNode(control(), not_null_obj, toop));
3016     // Failure path ends in uncommon trap (or may be dead - failure impossible)
3017     if (failure_control == NULL) {
3018       if (not_subtype_ctrl != top()) { // If failure is possible
3019         PreserveJVMState pjvms(this);
3020         set_control(not_subtype_ctrl);
3021         builtin_throw(Deoptimization::Reason_class_check, obj_klass);
3022       }
3023     } else {
3024       (*failure_control) = not_subtype_ctrl;
3025     }
3026   }
3027 
3028   region->init_req(_obj_path, control());
3029   phi   ->init_req(_obj_path, cast_obj);
3030 
3031   // A merge of NULL or Casted-NotNull obj
3032   Node* res = _gvn.transform(phi);
3033 
3034   // Note I do NOT always 'replace_in_map(obj,result)' here.
3035   //  if( tk->klass()->can_be_primary_super()  )
3036     // This means that if I successfully store an Object into an array-of-String
3037     // I 'forget' that the Object is really now known to be a String.  I have to
3038     // do this because we don't have true union types for interfaces - if I store
3039     // a Baz into an array-of-Interface and then tell the optimizer it's an
3040     // Interface, I forget that it's also a Baz and cannot do Baz-like field
3041     // references to it.  FIX THIS WHEN UNION TYPES APPEAR!
3042   //  replace_in_map( obj, res );
3043 
3044   // Return final merged results
3045   set_control( _gvn.transform(region) );
3046   record_for_igvn(region);
3047   return res;
3048 }
3049 
3050 //------------------------------next_monitor-----------------------------------
3051 // What number should be given to the next monitor?
3052 int GraphKit::next_monitor() {
3053   int current = jvms()->monitor_depth()* C->sync_stack_slots();
3054   int next = current + C->sync_stack_slots();
3055   // Keep the toplevel high water mark current:
3056   if (C->fixed_slots() < next)  C->set_fixed_slots(next);
3057   return current;
3058 }
3059 
3060 //------------------------------insert_mem_bar---------------------------------
3061 // Memory barrier to avoid floating things around
3062 // The membar serves as a pinch point between both control and all memory slices.
3063 Node* GraphKit::insert_mem_bar(int opcode, Node* precedent) {
3064   MemBarNode* mb = MemBarNode::make(C, opcode, Compile::AliasIdxBot, precedent);
3065   mb->init_req(TypeFunc::Control, control());
3066   mb->init_req(TypeFunc::Memory,  reset_memory());
3067   Node* membar = _gvn.transform(mb);
3068   set_control(_gvn.transform(new ProjNode(membar, TypeFunc::Control)));
3069   set_all_memory_call(membar);
3070   return membar;
3071 }
3072 
3073 //-------------------------insert_mem_bar_volatile----------------------------
3074 // Memory barrier to avoid floating things around
3075 // The membar serves as a pinch point between both control and memory(alias_idx).
3076 // If you want to make a pinch point on all memory slices, do not use this
3077 // function (even with AliasIdxBot); use insert_mem_bar() instead.
3078 Node* GraphKit::insert_mem_bar_volatile(int opcode, int alias_idx, Node* precedent) {
3079   // When Parse::do_put_xxx updates a volatile field, it appends a series
3080   // of MemBarVolatile nodes, one for *each* volatile field alias category.
3081   // The first membar is on the same memory slice as the field store opcode.
3082   // This forces the membar to follow the store.  (Bug 6500685 broke this.)
3083   // All the other membars (for other volatile slices, including AliasIdxBot,
3084   // which stands for all unknown volatile slices) are control-dependent
3085   // on the first membar.  This prevents later volatile loads or stores
3086   // from sliding up past the just-emitted store.
3087 
3088   MemBarNode* mb = MemBarNode::make(C, opcode, alias_idx, precedent);
3089   mb->set_req(TypeFunc::Control,control());
3090   if (alias_idx == Compile::AliasIdxBot) {
3091     mb->set_req(TypeFunc::Memory, merged_memory()->base_memory());
3092   } else {
3093     assert(!(opcode == Op_Initialize && alias_idx != Compile::AliasIdxRaw), "fix caller");
3094     mb->set_req(TypeFunc::Memory, memory(alias_idx));
3095   }
3096   Node* membar = _gvn.transform(mb);
3097   set_control(_gvn.transform(new ProjNode(membar, TypeFunc::Control)));
3098   if (alias_idx == Compile::AliasIdxBot) {
3099     merged_memory()->set_base_memory(_gvn.transform(new ProjNode(membar, TypeFunc::Memory)));
3100   } else {
3101     set_memory(_gvn.transform(new ProjNode(membar, TypeFunc::Memory)),alias_idx);
3102   }
3103   return membar;
3104 }
3105 
3106 //------------------------------shared_lock------------------------------------
3107 // Emit locking code.
3108 FastLockNode* GraphKit::shared_lock(Node* obj) {
3109   // bci is either a monitorenter bc or InvocationEntryBci
3110   // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
3111   assert(SynchronizationEntryBCI == InvocationEntryBci, "");
3112 
3113   if( !GenerateSynchronizationCode )
3114     return NULL;                // Not locking things?
3115   if (stopped())                // Dead monitor?
3116     return NULL;
3117 
3118   assert(dead_locals_are_killed(), "should kill locals before sync. point");
3119 
3120   // Box the stack location
3121   Node* box = _gvn.transform(new BoxLockNode(next_monitor()));
3122   Node* mem = reset_memory();
3123 
3124   FastLockNode * flock = _gvn.transform(new FastLockNode(0, obj, box) )->as_FastLock();
3125   if (UseBiasedLocking && PrintPreciseBiasedLockingStatistics) {
3126     // Create the counters for this fast lock.
3127     flock->create_lock_counter(sync_jvms()); // sync_jvms used to get current bci
3128   }
3129 
3130   // Create the rtm counters for this fast lock if needed.
3131   flock->create_rtm_lock_counter(sync_jvms()); // sync_jvms used to get current bci
3132 
3133   // Add monitor to debug info for the slow path.  If we block inside the
3134   // slow path and de-opt, we need the monitor hanging around
3135   map()->push_monitor( flock );
3136 
3137   const TypeFunc *tf = LockNode::lock_type();
3138   LockNode *lock = new LockNode(C, tf);
3139 
3140   lock->init_req( TypeFunc::Control, control() );
3141   lock->init_req( TypeFunc::Memory , mem );
3142   lock->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
3143   lock->init_req( TypeFunc::FramePtr, frameptr() );
3144   lock->init_req( TypeFunc::ReturnAdr, top() );
3145 
3146   lock->init_req(TypeFunc::Parms + 0, obj);
3147   lock->init_req(TypeFunc::Parms + 1, box);
3148   lock->init_req(TypeFunc::Parms + 2, flock);
3149   add_safepoint_edges(lock);
3150 
3151   lock = _gvn.transform( lock )->as_Lock();
3152 
3153   // lock has no side-effects, sets few values
3154   set_predefined_output_for_runtime_call(lock, mem, TypeRawPtr::BOTTOM);
3155 
3156   insert_mem_bar(Op_MemBarAcquireLock);
3157 
3158   // Add this to the worklist so that the lock can be eliminated
3159   record_for_igvn(lock);
3160 
3161 #ifndef PRODUCT
3162   if (PrintLockStatistics) {
3163     // Update the counter for this lock.  Don't bother using an atomic
3164     // operation since we don't require absolute accuracy.
3165     lock->create_lock_counter(map()->jvms());
3166     increment_counter(lock->counter()->addr());
3167   }
3168 #endif
3169 
3170   return flock;
3171 }
3172 
3173 
3174 //------------------------------shared_unlock----------------------------------
3175 // Emit unlocking code.
3176 void GraphKit::shared_unlock(Node* box, Node* obj) {
3177   // bci is either a monitorenter bc or InvocationEntryBci
3178   // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
3179   assert(SynchronizationEntryBCI == InvocationEntryBci, "");
3180 
3181   if( !GenerateSynchronizationCode )
3182     return;
3183   if (stopped()) {               // Dead monitor?
3184     map()->pop_monitor();        // Kill monitor from debug info
3185     return;
3186   }
3187 
3188   // Memory barrier to avoid floating things down past the locked region
3189   insert_mem_bar(Op_MemBarReleaseLock);
3190 
3191   const TypeFunc *tf = OptoRuntime::complete_monitor_exit_Type();
3192   UnlockNode *unlock = new UnlockNode(C, tf);
3193 #ifdef ASSERT
3194   unlock->set_dbg_jvms(sync_jvms());
3195 #endif
3196   uint raw_idx = Compile::AliasIdxRaw;
3197   unlock->init_req( TypeFunc::Control, control() );
3198   unlock->init_req( TypeFunc::Memory , memory(raw_idx) );
3199   unlock->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
3200   unlock->init_req( TypeFunc::FramePtr, frameptr() );
3201   unlock->init_req( TypeFunc::ReturnAdr, top() );
3202 
3203   unlock->init_req(TypeFunc::Parms + 0, obj);
3204   unlock->init_req(TypeFunc::Parms + 1, box);
3205   unlock = _gvn.transform(unlock)->as_Unlock();
3206 
3207   Node* mem = reset_memory();
3208 
3209   // unlock has no side-effects, sets few values
3210   set_predefined_output_for_runtime_call(unlock, mem, TypeRawPtr::BOTTOM);
3211 
3212   // Kill monitor from debug info
3213   map()->pop_monitor( );
3214 }
3215 
3216 //-------------------------------get_layout_helper-----------------------------
3217 // If the given klass is a constant or known to be an array,
3218 // fetch the constant layout helper value into constant_value
3219 // and return (Node*)NULL.  Otherwise, load the non-constant
3220 // layout helper value, and return the node which represents it.
3221 // This two-faced routine is useful because allocation sites
3222 // almost always feature constant types.
3223 Node* GraphKit::get_layout_helper(Node* klass_node, jint& constant_value) {
3224   const TypeKlassPtr* inst_klass = _gvn.type(klass_node)->isa_klassptr();
3225   if (!StressReflectiveCode && inst_klass != NULL) {
3226     ciKlass* klass = inst_klass->klass();
3227     assert(klass != NULL, "klass should not be NULL");
3228     bool    xklass = inst_klass->klass_is_exact();
3229     if (xklass || klass->is_array_klass()) {
3230       jint lhelper = klass->layout_helper();
3231       if (lhelper != Klass::_lh_neutral_value) {
3232         constant_value = lhelper;
3233         return (Node*) NULL;
3234       }
3235     }
3236   }
3237   constant_value = Klass::_lh_neutral_value;  // put in a known value
3238   Node* lhp = basic_plus_adr(klass_node, klass_node, in_bytes(Klass::layout_helper_offset()));
3239   return make_load(NULL, lhp, TypeInt::INT, T_INT, MemNode::unordered);
3240 }
3241 
3242 // We just put in an allocate/initialize with a big raw-memory effect.
3243 // Hook selected additional alias categories on the initialization.
3244 static void hook_memory_on_init(GraphKit& kit, int alias_idx,
3245                                 MergeMemNode* init_in_merge,
3246                                 Node* init_out_raw) {
3247   DEBUG_ONLY(Node* init_in_raw = init_in_merge->base_memory());
3248   assert(init_in_merge->memory_at(alias_idx) == init_in_raw, "");
3249 
3250   Node* prevmem = kit.memory(alias_idx);
3251   init_in_merge->set_memory_at(alias_idx, prevmem);
3252   kit.set_memory(init_out_raw, alias_idx);
3253 }
3254 
3255 //---------------------------set_output_for_allocation-------------------------
3256 Node* GraphKit::set_output_for_allocation(AllocateNode* alloc,
3257                                           const TypeOopPtr* oop_type,
3258                                           bool deoptimize_on_exception) {
3259   int rawidx = Compile::AliasIdxRaw;
3260   alloc->set_req( TypeFunc::FramePtr, frameptr() );
3261   add_safepoint_edges(alloc);
3262   Node* allocx = _gvn.transform(alloc);
3263   set_control( _gvn.transform(new ProjNode(allocx, TypeFunc::Control) ) );
3264   // create memory projection for i_o
3265   set_memory ( _gvn.transform( new ProjNode(allocx, TypeFunc::Memory, true) ), rawidx );
3266   make_slow_call_ex(allocx, env()->Throwable_klass(), true, deoptimize_on_exception);
3267 
3268   // create a memory projection as for the normal control path
3269   Node* malloc = _gvn.transform(new ProjNode(allocx, TypeFunc::Memory));
3270   set_memory(malloc, rawidx);
3271 
3272   // a normal slow-call doesn't change i_o, but an allocation does
3273   // we create a separate i_o projection for the normal control path
3274   set_i_o(_gvn.transform( new ProjNode(allocx, TypeFunc::I_O, false) ) );
3275   Node* rawoop = _gvn.transform( new ProjNode(allocx, TypeFunc::Parms) );
3276 
3277   // put in an initialization barrier
3278   InitializeNode* init = insert_mem_bar_volatile(Op_Initialize, rawidx,
3279                                                  rawoop)->as_Initialize();
3280   assert(alloc->initialization() == init,  "2-way macro link must work");
3281   assert(init ->allocation()     == alloc, "2-way macro link must work");
3282   {
3283     // Extract memory strands which may participate in the new object's
3284     // initialization, and source them from the new InitializeNode.
3285     // This will allow us to observe initializations when they occur,
3286     // and link them properly (as a group) to the InitializeNode.
3287     assert(init->in(InitializeNode::Memory) == malloc, "");
3288     MergeMemNode* minit_in = MergeMemNode::make(malloc);
3289     init->set_req(InitializeNode::Memory, minit_in);
3290     record_for_igvn(minit_in); // fold it up later, if possible
3291     Node* minit_out = memory(rawidx);
3292     assert(minit_out->is_Proj() && minit_out->in(0) == init, "");
3293     if (oop_type->isa_aryptr()) {
3294       const TypePtr* telemref = oop_type->add_offset(Type::OffsetBot);
3295       int            elemidx  = C->get_alias_index(telemref);
3296       hook_memory_on_init(*this, elemidx, minit_in, minit_out);
3297     } else if (oop_type->isa_instptr() || oop_type->isa_valuetypeptr()) {
3298       ciInstanceKlass* ik = oop_type->klass()->as_instance_klass();
3299       for (int i = 0, len = ik->nof_nonstatic_fields(); i < len; i++) {
3300         ciField* field = ik->nonstatic_field_at(i);
3301         if (field->offset() >= TrackedInitializationLimit * HeapWordSize)
3302           continue;  // do not bother to track really large numbers of fields
3303         // Find (or create) the alias category for this field:
3304         int fieldidx = C->alias_type(field)->index();
3305         hook_memory_on_init(*this, fieldidx, minit_in, minit_out);
3306       }
3307     }
3308   }
3309 
3310   // Cast raw oop to the real thing...
3311   Node* javaoop = new CheckCastPPNode(control(), rawoop, oop_type);
3312   javaoop = _gvn.transform(javaoop);
3313   C->set_recent_alloc(control(), javaoop);
3314   assert(just_allocated_object(control()) == javaoop, "just allocated");
3315 
3316 #ifdef ASSERT
3317   { // Verify that the AllocateNode::Ideal_allocation recognizers work:
3318     assert(AllocateNode::Ideal_allocation(rawoop, &_gvn) == alloc,
3319            "Ideal_allocation works");
3320     assert(AllocateNode::Ideal_allocation(javaoop, &_gvn) == alloc,
3321            "Ideal_allocation works");
3322     if (alloc->is_AllocateArray()) {
3323       assert(AllocateArrayNode::Ideal_array_allocation(rawoop, &_gvn) == alloc->as_AllocateArray(),
3324              "Ideal_allocation works");
3325       assert(AllocateArrayNode::Ideal_array_allocation(javaoop, &_gvn) == alloc->as_AllocateArray(),
3326              "Ideal_allocation works");
3327     } else {
3328       assert(alloc->in(AllocateNode::ALength)->is_top(), "no length, please");
3329     }
3330   }
3331 #endif //ASSERT
3332 
3333   return javaoop;
3334 }
3335 
3336 //---------------------------new_instance--------------------------------------
3337 // This routine takes a klass_node which may be constant (for a static type)
3338 // or may be non-constant (for reflective code).  It will work equally well
3339 // for either, and the graph will fold nicely if the optimizer later reduces
3340 // the type to a constant.
3341 // The optional arguments are for specialized use by intrinsics:
3342 //  - If 'extra_slow_test' if not null is an extra condition for the slow-path.
3343 //  - If 'return_size_val', report the the total object size to the caller.
3344 //  - deoptimize_on_exception controls how Java exceptions are handled (rethrow vs deoptimize)
3345 Node* GraphKit::new_instance(Node* klass_node,
3346                              Node* extra_slow_test,
3347                              Node* *return_size_val,
3348                              bool deoptimize_on_exception,
3349                              ValueTypeNode* value_node) {
3350   // Compute size in doublewords
3351   // The size is always an integral number of doublewords, represented
3352   // as a positive bytewise size stored in the klass's layout_helper.
3353   // The layout_helper also encodes (in a low bit) the need for a slow path.
3354   jint  layout_con = Klass::_lh_neutral_value;
3355   Node* layout_val = get_layout_helper(klass_node, layout_con);
3356   int   layout_is_con = (layout_val == NULL);
3357 
3358   if (extra_slow_test == NULL)  extra_slow_test = intcon(0);
3359   // Generate the initial go-slow test.  It's either ALWAYS (return a
3360   // Node for 1) or NEVER (return a NULL) or perhaps (in the reflective
3361   // case) a computed value derived from the layout_helper.
3362   Node* initial_slow_test = NULL;
3363   if (layout_is_con) {
3364     assert(!StressReflectiveCode, "stress mode does not use these paths");
3365     bool must_go_slow = Klass::layout_helper_needs_slow_path(layout_con);
3366     initial_slow_test = must_go_slow ? intcon(1) : extra_slow_test;
3367   } else {   // reflective case
3368     // This reflective path is used by Unsafe.allocateInstance.
3369     // (It may be stress-tested by specifying StressReflectiveCode.)
3370     // Basically, we want to get into the VM is there's an illegal argument.
3371     Node* bit = intcon(Klass::_lh_instance_slow_path_bit);
3372     initial_slow_test = _gvn.transform( new AndINode(layout_val, bit) );
3373     if (extra_slow_test != intcon(0)) {
3374       initial_slow_test = _gvn.transform( new OrINode(initial_slow_test, extra_slow_test) );
3375     }
3376     // (Macro-expander will further convert this to a Bool, if necessary.)
3377   }
3378 
3379   // Find the size in bytes.  This is easy; it's the layout_helper.
3380   // The size value must be valid even if the slow path is taken.
3381   Node* size = NULL;
3382   if (layout_is_con) {
3383     size = MakeConX(Klass::layout_helper_size_in_bytes(layout_con));
3384   } else {   // reflective case
3385     // This reflective path is used by clone and Unsafe.allocateInstance.
3386     size = ConvI2X(layout_val);
3387 
3388     // Clear the low bits to extract layout_helper_size_in_bytes:
3389     assert((int)Klass::_lh_instance_slow_path_bit < BytesPerLong, "clear bit");
3390     Node* mask = MakeConX(~ (intptr_t)right_n_bits(LogBytesPerLong));
3391     size = _gvn.transform( new AndXNode(size, mask) );
3392   }
3393   if (return_size_val != NULL) {
3394     (*return_size_val) = size;
3395   }
3396 
3397   // This is a precise notnull oop of the klass.
3398   // (Actually, it need not be precise if this is a reflective allocation.)
3399   // It's what we cast the result to.
3400   const TypeKlassPtr* tklass = _gvn.type(klass_node)->isa_klassptr();
3401   if (!tklass)  tklass = TypeKlassPtr::OBJECT;
3402   const TypeOopPtr* oop_type = tklass->as_instance_type();
3403 
3404   // Now generate allocation code
3405 
3406   // The entire memory state is needed for slow path of the allocation
3407   // since GC and deoptimization can happen.
3408   Node *mem = reset_memory();
3409   set_all_memory(mem); // Create new memory state
3410 
3411   AllocateNode* alloc = new AllocateNode(C, AllocateNode::alloc_type(Type::TOP),
3412                                          control(), mem, i_o(),
3413                                          size, klass_node,
3414                                          initial_slow_test, value_node);
3415 
3416   return set_output_for_allocation(alloc, oop_type, deoptimize_on_exception);
3417 }
3418 
3419 //-------------------------------new_array-------------------------------------
3420 // helper for newarray and anewarray
3421 // The 'length' parameter is (obviously) the length of the array.
3422 // See comments on new_instance for the meaning of the other arguments.
3423 Node* GraphKit::new_array(Node* klass_node,     // array klass (maybe variable)
3424                           Node* length,         // number of array elements
3425                           int   nargs,          // number of arguments to push back for uncommon trap
3426                           Node* *return_size_val,
3427                           bool deoptimize_on_exception) {
3428   jint  layout_con = Klass::_lh_neutral_value;
3429   Node* layout_val = get_layout_helper(klass_node, layout_con);
3430   int   layout_is_con = (layout_val == NULL);
3431 
3432   if (!layout_is_con && !StressReflectiveCode &&
3433       !too_many_traps(Deoptimization::Reason_class_check)) {
3434     // This is a reflective array creation site.
3435     // Optimistically assume that it is a subtype of Object[],
3436     // so that we can fold up all the address arithmetic.
3437     layout_con = Klass::array_layout_helper(T_OBJECT);
3438     Node* cmp_lh = _gvn.transform( new CmpINode(layout_val, intcon(layout_con)) );
3439     Node* bol_lh = _gvn.transform( new BoolNode(cmp_lh, BoolTest::eq) );
3440     { BuildCutout unless(this, bol_lh, PROB_MAX);
3441       inc_sp(nargs);
3442       uncommon_trap(Deoptimization::Reason_class_check,
3443                     Deoptimization::Action_maybe_recompile);
3444     }
3445     layout_val = NULL;
3446     layout_is_con = true;
3447   }
3448 
3449   // Generate the initial go-slow test.  Make sure we do not overflow
3450   // if length is huge (near 2Gig) or negative!  We do not need
3451   // exact double-words here, just a close approximation of needed
3452   // double-words.  We can't add any offset or rounding bits, lest we
3453   // take a size -1 of bytes and make it positive.  Use an unsigned
3454   // compare, so negative sizes look hugely positive.
3455   int fast_size_limit = FastAllocateSizeLimit;
3456   if (layout_is_con) {
3457     assert(!StressReflectiveCode, "stress mode does not use these paths");
3458     // Increase the size limit if we have exact knowledge of array type.
3459     int log2_esize = Klass::layout_helper_log2_element_size(layout_con);
3460     fast_size_limit <<= (LogBytesPerLong - log2_esize);
3461   }
3462 
3463   Node* initial_slow_cmp  = _gvn.transform( new CmpUNode( length, intcon( fast_size_limit ) ) );
3464   Node* initial_slow_test = _gvn.transform( new BoolNode( initial_slow_cmp, BoolTest::gt ) );
3465 
3466   // --- Size Computation ---
3467   // array_size = round_to_heap(array_header + (length << elem_shift));
3468   // where round_to_heap(x) == round_to(x, MinObjAlignmentInBytes)
3469   // and round_to(x, y) == ((x + y-1) & ~(y-1))
3470   // The rounding mask is strength-reduced, if possible.
3471   int round_mask = MinObjAlignmentInBytes - 1;
3472   Node* header_size = NULL;
3473   int   header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
3474   // (T_BYTE has the weakest alignment and size restrictions...)
3475   if (layout_is_con) {
3476     int       hsize  = Klass::layout_helper_header_size(layout_con);
3477     int       eshift = Klass::layout_helper_log2_element_size(layout_con);
3478     BasicType etype  = Klass::layout_helper_element_type(layout_con);
3479     bool is_value_array = Klass::layout_helper_is_valueArray(layout_con);
3480     if ((round_mask & ~right_n_bits(eshift)) == 0)
3481       round_mask = 0;  // strength-reduce it if it goes away completely
3482     assert(is_value_array || (hsize & right_n_bits(eshift)) == 0, "hsize is pre-rounded");
3483     assert(header_size_min <= hsize, "generic minimum is smallest");
3484     header_size_min = hsize;
3485     header_size = intcon(hsize + round_mask);
3486   } else {
3487     Node* hss   = intcon(Klass::_lh_header_size_shift);
3488     Node* hsm   = intcon(Klass::_lh_header_size_mask);
3489     Node* hsize = _gvn.transform( new URShiftINode(layout_val, hss) );
3490     hsize       = _gvn.transform( new AndINode(hsize, hsm) );
3491     Node* mask  = intcon(round_mask);
3492     header_size = _gvn.transform( new AddINode(hsize, mask) );
3493   }
3494 
3495   Node* elem_shift = NULL;
3496   if (layout_is_con) {
3497     int eshift = Klass::layout_helper_log2_element_size(layout_con);
3498     if (eshift != 0)
3499       elem_shift = intcon(eshift);
3500   } else {
3501     // There is no need to mask or shift this value.
3502     // The semantics of LShiftINode include an implicit mask to 0x1F.
3503     assert(Klass::_lh_log2_element_size_shift == 0, "use shift in place");
3504     elem_shift = layout_val;
3505   }
3506 
3507   // Transition to native address size for all offset calculations:
3508   Node* lengthx = ConvI2X(length);
3509   Node* headerx = ConvI2X(header_size);
3510 #ifdef _LP64
3511   { const TypeInt* tilen = _gvn.find_int_type(length);
3512     if (tilen != NULL && tilen->_lo < 0) {
3513       // Add a manual constraint to a positive range.  Cf. array_element_address.
3514       jint size_max = fast_size_limit;
3515       if (size_max > tilen->_hi)  size_max = tilen->_hi;
3516       const TypeInt* tlcon = TypeInt::make(0, size_max, Type::WidenMin);
3517 
3518       // Only do a narrow I2L conversion if the range check passed.
3519       IfNode* iff = new IfNode(control(), initial_slow_test, PROB_MIN, COUNT_UNKNOWN);
3520       _gvn.transform(iff);
3521       RegionNode* region = new RegionNode(3);
3522       _gvn.set_type(region, Type::CONTROL);
3523       lengthx = new PhiNode(region, TypeLong::LONG);
3524       _gvn.set_type(lengthx, TypeLong::LONG);
3525 
3526       // Range check passed. Use ConvI2L node with narrow type.
3527       Node* passed = IfFalse(iff);
3528       region->init_req(1, passed);
3529       // Make I2L conversion control dependent to prevent it from
3530       // floating above the range check during loop optimizations.
3531       lengthx->init_req(1, C->constrained_convI2L(&_gvn, length, tlcon, passed));
3532 
3533       // Range check failed. Use ConvI2L with wide type because length may be invalid.
3534       region->init_req(2, IfTrue(iff));
3535       lengthx->init_req(2, ConvI2X(length));
3536 
3537       set_control(region);
3538       record_for_igvn(region);
3539       record_for_igvn(lengthx);
3540     }
3541   }
3542 #endif
3543 
3544   // Combine header size (plus rounding) and body size.  Then round down.
3545   // This computation cannot overflow, because it is used only in two
3546   // places, one where the length is sharply limited, and the other
3547   // after a successful allocation.
3548   Node* abody = lengthx;
3549   if (elem_shift != NULL)
3550     abody     = _gvn.transform( new LShiftXNode(lengthx, elem_shift) );
3551   Node* size  = _gvn.transform( new AddXNode(headerx, abody) );
3552   if (round_mask != 0) {
3553     Node* mask = MakeConX(~round_mask);
3554     size       = _gvn.transform( new AndXNode(size, mask) );
3555   }
3556   // else if round_mask == 0, the size computation is self-rounding
3557 
3558   if (return_size_val != NULL) {
3559     // This is the size
3560     (*return_size_val) = size;
3561   }
3562 
3563   // Now generate allocation code
3564 
3565   // The entire memory state is needed for slow path of the allocation
3566   // since GC and deoptimization can happen.
3567   Node *mem = reset_memory();
3568   set_all_memory(mem); // Create new memory state
3569 
3570   if (initial_slow_test->is_Bool()) {
3571     // Hide it behind a CMoveI, or else PhaseIdealLoop::split_up will get sick.
3572     initial_slow_test = initial_slow_test->as_Bool()->as_int_value(&_gvn);
3573   }
3574 
3575   // Create the AllocateArrayNode and its result projections
3576   AllocateArrayNode* alloc
3577     = new AllocateArrayNode(C, AllocateArrayNode::alloc_type(TypeInt::INT),
3578                             control(), mem, i_o(),
3579                             size, klass_node,
3580                             initial_slow_test,
3581                             length);
3582 
3583   // Cast to correct type.  Note that the klass_node may be constant or not,
3584   // and in the latter case the actual array type will be inexact also.
3585   // (This happens via a non-constant argument to inline_native_newArray.)
3586   // In any case, the value of klass_node provides the desired array type.
3587   const TypeInt* length_type = _gvn.find_int_type(length);
3588   const TypeOopPtr* ary_type = _gvn.type(klass_node)->is_klassptr()->as_instance_type();
3589   if (ary_type->isa_aryptr() && length_type != NULL) {
3590     // Try to get a better type than POS for the size
3591     ary_type = ary_type->is_aryptr()->cast_to_size(length_type);
3592   }
3593 
3594   Node* javaoop = set_output_for_allocation(alloc, ary_type, deoptimize_on_exception);
3595 
3596   // Cast length on remaining path to be as narrow as possible
3597   if (map()->find_edge(length) >= 0) {
3598     Node* ccast = alloc->make_ideal_length(ary_type, &_gvn);
3599     if (ccast != length) {
3600       _gvn.set_type_bottom(ccast);
3601       record_for_igvn(ccast);
3602       replace_in_map(length, ccast);
3603     }
3604   }
3605 
3606   const TypeAryPtr* ary_ptr = ary_type->isa_aryptr();
3607   ciKlass* elem_klass = ary_ptr != NULL ? ary_ptr->klass()->as_array_klass()->element_klass() : NULL;
3608   if (elem_klass != NULL && elem_klass->is_valuetype()) {
3609     ciValueKlass* vk = elem_klass->as_value_klass();
3610     if (!vk->flatten_array()) {
3611       // Non-flattened value type arrays need to be initialized with default value type oops
3612       initialize_value_type_array(javaoop, length, elem_klass->as_value_klass(), nargs);
3613       InitializeNode* init = alloc->initialization();
3614       init->set_complete_with_arraycopy();
3615     }
3616   }
3617 
3618   return javaoop;
3619 }
3620 
3621 void GraphKit::initialize_value_type_array(Node* array, Node* length, ciValueKlass* vk, int nargs) {
3622   // Check for zero length
3623   Node* null_ctl = top();
3624   null_check_common(length, T_INT, false, &null_ctl, false);
3625   if (stopped()) {
3626     set_control(null_ctl); // Always zero
3627     return;
3628   }
3629 
3630   // Prepare for merging control and IO
3631   RegionNode* res_ctl = new RegionNode(3);
3632   res_ctl->init_req(1, null_ctl);
3633   gvn().set_type(res_ctl, Type::CONTROL);
3634   record_for_igvn(res_ctl);
3635   Node* res_io = PhiNode::make(res_ctl, i_o(), Type::ABIO);
3636   gvn().set_type(res_io, Type::ABIO);
3637   record_for_igvn(res_io);
3638 
3639   // TODO comment
3640   SafePointNode* loop_map = NULL;
3641   {
3642     PreserveJVMState pjvms(this);
3643     // Create default value type and store it to memory
3644     Node* oop = ValueTypeNode::make_default(gvn(), vk);
3645     oop = oop->as_ValueType()->allocate(this);
3646 
3647     length = SubI(length, intcon(1));
3648     add_predicate(nargs);
3649     RegionNode* loop = new RegionNode(3);
3650     loop->init_req(1, control());
3651     gvn().set_type(loop, Type::CONTROL);
3652     record_for_igvn(loop);
3653 
3654     Node* index = new PhiNode(loop, TypeInt::INT);
3655     index->init_req(1, intcon(0));
3656     gvn().set_type(index, TypeInt::INT);
3657     record_for_igvn(index);
3658 
3659     // TODO explain why we need to capture all memory
3660     PhiNode* mem = new PhiNode(loop, Type::MEMORY, TypePtr::BOTTOM);
3661     mem->init_req(1, reset_memory());
3662     gvn().set_type(mem, Type::MEMORY);
3663     record_for_igvn(mem);
3664     set_control(loop);
3665     set_all_memory(mem);
3666     // Initialize array element
3667     Node* adr = array_element_address(array, index, T_OBJECT);
3668     const TypeOopPtr* elemtype = TypeValueTypePtr::make(TypePtr::NotNull, vk);
3669     Node* store = store_oop_to_array(control(), array, adr, TypeAryPtr::OOPS, oop, elemtype, T_OBJECT, MemNode::release);
3670 
3671     IfNode* iff = create_and_map_if(control(), Bool(CmpI(index, length), BoolTest::lt), PROB_FAIR, COUNT_UNKNOWN);
3672     loop->init_req(2, IfTrue(iff));
3673     mem->init_req(2, merged_memory());
3674     index->init_req(2, AddI(index, intcon(1)));
3675 
3676     res_ctl->init_req(2, IfFalse(iff));
3677     res_io->set_req(2, i_o());
3678     loop_map = stop();
3679   }
3680   // Set merged control, IO and memory
3681   set_control(res_ctl);
3682   set_i_o(res_io);
3683   merge_memory(loop_map->merged_memory(), res_ctl, 2);
3684 
3685   // Transform new memory Phis.
3686   for (MergeMemStream mms(merged_memory()); mms.next_non_empty();) {
3687     Node* phi = mms.memory();
3688     if (phi->is_Phi() && phi->in(0) == res_ctl) {
3689       mms.set_memory(gvn().transform(phi));
3690     }
3691   }
3692 }
3693 
3694 // The following "Ideal_foo" functions are placed here because they recognize
3695 // the graph shapes created by the functions immediately above.
3696 
3697 //---------------------------Ideal_allocation----------------------------------
3698 // Given an oop pointer or raw pointer, see if it feeds from an AllocateNode.
3699 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase) {
3700   if (ptr == NULL) {     // reduce dumb test in callers
3701     return NULL;
3702   }
3703   if (ptr->is_CheckCastPP()) { // strip only one raw-to-oop cast
3704     ptr = ptr->in(1);
3705     if (ptr == NULL) return NULL;
3706   }
3707   // Return NULL for allocations with several casts:
3708   //   j.l.reflect.Array.newInstance(jobject, jint)
3709   //   Object.clone()
3710   // to keep more precise type from last cast.
3711   if (ptr->is_Proj()) {
3712     Node* allo = ptr->in(0);
3713     if (allo != NULL && allo->is_Allocate()) {
3714       return allo->as_Allocate();
3715     }
3716   }
3717   // Report failure to match.
3718   return NULL;
3719 }
3720 
3721 // Fancy version which also strips off an offset (and reports it to caller).
3722 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase,
3723                                              intptr_t& offset) {
3724   Node* base = AddPNode::Ideal_base_and_offset(ptr, phase, offset);
3725   if (base == NULL)  return NULL;
3726   return Ideal_allocation(base, phase);
3727 }
3728 
3729 // Trace Initialize <- Proj[Parm] <- Allocate
3730 AllocateNode* InitializeNode::allocation() {
3731   Node* rawoop = in(InitializeNode::RawAddress);
3732   if (rawoop->is_Proj()) {
3733     Node* alloc = rawoop->in(0);
3734     if (alloc->is_Allocate()) {
3735       return alloc->as_Allocate();
3736     }
3737   }
3738   return NULL;
3739 }
3740 
3741 // Trace Allocate -> Proj[Parm] -> Initialize
3742 InitializeNode* AllocateNode::initialization() {
3743   ProjNode* rawoop = proj_out(AllocateNode::RawAddress);
3744   if (rawoop == NULL)  return NULL;
3745   for (DUIterator_Fast imax, i = rawoop->fast_outs(imax); i < imax; i++) {
3746     Node* init = rawoop->fast_out(i);
3747     if (init->is_Initialize()) {
3748       assert(init->as_Initialize()->allocation() == this, "2-way link");
3749       return init->as_Initialize();
3750     }
3751   }
3752   return NULL;
3753 }
3754 
3755 //----------------------------- loop predicates ---------------------------
3756 
3757 //------------------------------add_predicate_impl----------------------------
3758 void GraphKit::add_predicate_impl(Deoptimization::DeoptReason reason, int nargs) {
3759   // Too many traps seen?
3760   if (too_many_traps(reason)) {
3761 #ifdef ASSERT
3762     if (TraceLoopPredicate) {
3763       int tc = C->trap_count(reason);
3764       tty->print("too many traps=%s tcount=%d in ",
3765                     Deoptimization::trap_reason_name(reason), tc);
3766       method()->print(); // which method has too many predicate traps
3767       tty->cr();
3768     }
3769 #endif
3770     // We cannot afford to take more traps here,
3771     // do not generate predicate.
3772     return;
3773   }
3774 
3775   Node *cont    = _gvn.intcon(1);
3776   Node* opq     = _gvn.transform(new Opaque1Node(C, cont));
3777   Node *bol     = _gvn.transform(new Conv2BNode(opq));
3778   IfNode* iff   = create_and_map_if(control(), bol, PROB_MAX, COUNT_UNKNOWN);
3779   Node* iffalse = _gvn.transform(new IfFalseNode(iff));
3780   C->add_predicate_opaq(opq);
3781   {
3782     PreserveJVMState pjvms(this);
3783     set_control(iffalse);
3784     inc_sp(nargs);
3785     uncommon_trap(reason, Deoptimization::Action_maybe_recompile);
3786   }
3787   Node* iftrue = _gvn.transform(new IfTrueNode(iff));
3788   set_control(iftrue);
3789 }
3790 
3791 //------------------------------add_predicate---------------------------------
3792 void GraphKit::add_predicate(int nargs) {
3793   if (UseLoopPredicate) {
3794     add_predicate_impl(Deoptimization::Reason_predicate, nargs);
3795   }
3796   // loop's limit check predicate should be near the loop.
3797   add_predicate_impl(Deoptimization::Reason_loop_limit_check, nargs);
3798 }
3799 
3800 //----------------------------- store barriers ----------------------------
3801 #define __ ideal.
3802 
3803 void GraphKit::sync_kit(IdealKit& ideal) {
3804   set_all_memory(__ merged_memory());
3805   set_i_o(__ i_o());
3806   set_control(__ ctrl());
3807 }
3808 
3809 void GraphKit::final_sync(IdealKit& ideal) {
3810   // Final sync IdealKit and graphKit.
3811   sync_kit(ideal);
3812 }
3813 
3814 Node* GraphKit::byte_map_base_node() {
3815   // Get base of card map
3816   CardTableModRefBS* ct =
3817     barrier_set_cast<CardTableModRefBS>(Universe::heap()->barrier_set());
3818   assert(sizeof(*ct->byte_map_base) == sizeof(jbyte), "adjust users of this code");
3819   if (ct->byte_map_base != NULL) {
3820     return makecon(TypeRawPtr::make((address)ct->byte_map_base));
3821   } else {
3822     return null();
3823   }
3824 }
3825 
3826 // vanilla/CMS post barrier
3827 // Insert a write-barrier store.  This is to let generational GC work; we have
3828 // to flag all oop-stores before the next GC point.
3829 void GraphKit::write_barrier_post(Node* oop_store,
3830                                   Node* obj,
3831                                   Node* adr,
3832                                   uint  adr_idx,
3833                                   Node* val,
3834                                   bool use_precise) {
3835   // No store check needed if we're storing a NULL or an old object
3836   // (latter case is probably a string constant). The concurrent
3837   // mark sweep garbage collector, however, needs to have all nonNull
3838   // oop updates flagged via card-marks.
3839   if (val != NULL && val->is_Con()) {
3840     // must be either an oop or NULL
3841     const Type* t = val->bottom_type();
3842     if (t == TypePtr::NULL_PTR || t == Type::TOP)
3843       // stores of null never (?) need barriers
3844       return;
3845   }
3846 
3847   if (use_ReduceInitialCardMarks()
3848       && obj == just_allocated_object(control())) {
3849     // We can skip marks on a freshly-allocated object in Eden.
3850     // Keep this code in sync with new_store_pre_barrier() in runtime.cpp.
3851     // That routine informs GC to take appropriate compensating steps,
3852     // upon a slow-path allocation, so as to make this card-mark
3853     // elision safe.
3854     return;
3855   }
3856 
3857   if (!use_precise) {
3858     // All card marks for a (non-array) instance are in one place:
3859     adr = obj;
3860   }
3861   // (Else it's an array (or unknown), and we want more precise card marks.)
3862   assert(adr != NULL, "");
3863 
3864   IdealKit ideal(this, true);
3865 
3866   // Convert the pointer to an int prior to doing math on it
3867   Node* cast = __ CastPX(__ ctrl(), adr);
3868 
3869   // Divide by card size
3870   assert(Universe::heap()->barrier_set()->is_a(BarrierSet::CardTableModRef),
3871          "Only one we handle so far.");
3872   Node* card_offset = __ URShiftX( cast, __ ConI(CardTableModRefBS::card_shift) );
3873 
3874   // Combine card table base and card offset
3875   Node* card_adr = __ AddP(__ top(), byte_map_base_node(), card_offset );
3876 
3877   // Get the alias_index for raw card-mark memory
3878   int adr_type = Compile::AliasIdxRaw;
3879   Node*   zero = __ ConI(0); // Dirty card value
3880   BasicType bt = T_BYTE;
3881 
3882   if (UseConcMarkSweepGC && UseCondCardMark) {
3883     insert_mem_bar(Op_MemBarVolatile);   // StoreLoad barrier
3884     __ sync_kit(this);
3885   }
3886 
3887   if (UseCondCardMark) {
3888     // The classic GC reference write barrier is typically implemented
3889     // as a store into the global card mark table.  Unfortunately
3890     // unconditional stores can result in false sharing and excessive
3891     // coherence traffic as well as false transactional aborts.
3892     // UseCondCardMark enables MP "polite" conditional card mark
3893     // stores.  In theory we could relax the load from ctrl() to
3894     // no_ctrl, but that doesn't buy much latitude.
3895     Node* card_val = __ load( __ ctrl(), card_adr, TypeInt::BYTE, bt, adr_type);
3896     __ if_then(card_val, BoolTest::ne, zero);
3897   }
3898 
3899   // Smash zero into card
3900   if( !UseConcMarkSweepGC ) {
3901     __ store(__ ctrl(), card_adr, zero, bt, adr_type, MemNode::unordered);
3902   } else {
3903     // Specialized path for CM store barrier
3904     __ storeCM(__ ctrl(), card_adr, zero, oop_store, adr_idx, bt, adr_type);
3905   }
3906 
3907   if (UseCondCardMark) {
3908     __ end_if();
3909   }
3910 
3911   // Final sync IdealKit and GraphKit.
3912   final_sync(ideal);
3913 }
3914 /*
3915  * Determine if the G1 pre-barrier can be removed. The pre-barrier is
3916  * required by SATB to make sure all objects live at the start of the
3917  * marking are kept alive, all reference updates need to any previous
3918  * reference stored before writing.
3919  *
3920  * If the previous value is NULL there is no need to save the old value.
3921  * References that are NULL are filtered during runtime by the barrier
3922  * code to avoid unnecessary queuing.
3923  *
3924  * However in the case of newly allocated objects it might be possible to
3925  * prove that the reference about to be overwritten is NULL during compile
3926  * time and avoid adding the barrier code completely.
3927  *
3928  * The compiler needs to determine that the object in which a field is about
3929  * to be written is newly allocated, and that no prior store to the same field
3930  * has happened since the allocation.
3931  *
3932  * Returns true if the pre-barrier can be removed
3933  */
3934 bool GraphKit::g1_can_remove_pre_barrier(PhaseTransform* phase, Node* adr,
3935                                          BasicType bt, uint adr_idx) {
3936   intptr_t offset = 0;
3937   Node* base = AddPNode::Ideal_base_and_offset(adr, phase, offset);
3938   AllocateNode* alloc = AllocateNode::Ideal_allocation(base, phase);
3939 
3940   if (offset == Type::OffsetBot) {
3941     return false; // cannot unalias unless there are precise offsets
3942   }
3943 
3944   if (alloc == NULL) {
3945     return false; // No allocation found
3946   }
3947 
3948   intptr_t size_in_bytes = type2aelembytes(bt);
3949 
3950   Node* mem = memory(adr_idx); // start searching here...
3951 
3952   for (int cnt = 0; cnt < 50; cnt++) {
3953 
3954     if (mem->is_Store()) {
3955 
3956       Node* st_adr = mem->in(MemNode::Address);
3957       intptr_t st_offset = 0;
3958       Node* st_base = AddPNode::Ideal_base_and_offset(st_adr, phase, st_offset);
3959 
3960       if (st_base == NULL) {
3961         break; // inscrutable pointer
3962       }
3963 
3964       // Break we have found a store with same base and offset as ours so break
3965       if (st_base == base && st_offset == offset) {
3966         break;
3967       }
3968 
3969       if (st_offset != offset && st_offset != Type::OffsetBot) {
3970         const int MAX_STORE = BytesPerLong;
3971         if (st_offset >= offset + size_in_bytes ||
3972             st_offset <= offset - MAX_STORE ||
3973             st_offset <= offset - mem->as_Store()->memory_size()) {
3974           // Success:  The offsets are provably independent.
3975           // (You may ask, why not just test st_offset != offset and be done?
3976           // The answer is that stores of different sizes can co-exist
3977           // in the same sequence of RawMem effects.  We sometimes initialize
3978           // a whole 'tile' of array elements with a single jint or jlong.)
3979           mem = mem->in(MemNode::Memory);
3980           continue; // advance through independent store memory
3981         }
3982       }
3983 
3984       if (st_base != base
3985           && MemNode::detect_ptr_independence(base, alloc, st_base,
3986                                               AllocateNode::Ideal_allocation(st_base, phase),
3987                                               phase)) {
3988         // Success:  The bases are provably independent.
3989         mem = mem->in(MemNode::Memory);
3990         continue; // advance through independent store memory
3991       }
3992     } else if (mem->is_Proj() && mem->in(0)->is_Initialize()) {
3993 
3994       InitializeNode* st_init = mem->in(0)->as_Initialize();
3995       AllocateNode* st_alloc = st_init->allocation();
3996 
3997       // Make sure that we are looking at the same allocation site.
3998       // The alloc variable is guaranteed to not be null here from earlier check.
3999       if (alloc == st_alloc) {
4000         // Check that the initialization is storing NULL so that no previous store
4001         // has been moved up and directly write a reference
4002         Node* captured_store = st_init->find_captured_store(offset,
4003                                                             type2aelembytes(T_OBJECT),
4004                                                             phase);
4005         if (captured_store == NULL || captured_store == st_init->zero_memory()) {
4006           return true;
4007         }
4008       }
4009     }
4010 
4011     // Unless there is an explicit 'continue', we must bail out here,
4012     // because 'mem' is an inscrutable memory state (e.g., a call).
4013     break;
4014   }
4015 
4016   return false;
4017 }
4018 
4019 // G1 pre/post barriers
4020 void GraphKit::g1_write_barrier_pre(bool do_load,
4021                                     Node* obj,
4022                                     Node* adr,
4023                                     uint alias_idx,
4024                                     Node* val,
4025                                     const TypeOopPtr* val_type,
4026                                     Node* pre_val,
4027                                     BasicType bt) {
4028 
4029   // Some sanity checks
4030   // Note: val is unused in this routine.
4031 
4032   if (do_load) {
4033     // We need to generate the load of the previous value
4034     assert(obj != NULL, "must have a base");
4035     assert(adr != NULL, "where are loading from?");
4036     assert(pre_val == NULL, "loaded already?");
4037     assert(val_type != NULL, "need a type");
4038 
4039     if (use_ReduceInitialCardMarks()
4040         && g1_can_remove_pre_barrier(&_gvn, adr, bt, alias_idx)) {
4041       return;
4042     }
4043 
4044   } else {
4045     // In this case both val_type and alias_idx are unused.
4046     assert(pre_val != NULL, "must be loaded already");
4047     // Nothing to be done if pre_val is null.
4048     if (pre_val->bottom_type() == TypePtr::NULL_PTR) return;
4049     assert(pre_val->bottom_type()->basic_type() == T_OBJECT, "or we shouldn't be here");
4050   }
4051   assert(bt == T_OBJECT || bt == T_VALUETYPE, "or we shouldn't be here");
4052 
4053   IdealKit ideal(this, true);
4054 
4055   Node* tls = __ thread(); // ThreadLocalStorage
4056 
4057   Node* no_ctrl = NULL;
4058   Node* no_base = __ top();
4059   Node* zero  = __ ConI(0);
4060   Node* zeroX = __ ConX(0);
4061 
4062   float likely  = PROB_LIKELY(0.999);
4063   float unlikely  = PROB_UNLIKELY(0.999);
4064 
4065   BasicType active_type = in_bytes(SATBMarkQueue::byte_width_of_active()) == 4 ? T_INT : T_BYTE;
4066   assert(in_bytes(SATBMarkQueue::byte_width_of_active()) == 4 || in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "flag width");
4067 
4068   // Offsets into the thread
4069   const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() +  // 648
4070                                           SATBMarkQueue::byte_offset_of_active());
4071   const int index_offset   = in_bytes(JavaThread::satb_mark_queue_offset() +  // 656
4072                                           SATBMarkQueue::byte_offset_of_index());
4073   const int buffer_offset  = in_bytes(JavaThread::satb_mark_queue_offset() +  // 652
4074                                           SATBMarkQueue::byte_offset_of_buf());
4075 
4076   // Now the actual pointers into the thread
4077   Node* marking_adr = __ AddP(no_base, tls, __ ConX(marking_offset));
4078   Node* buffer_adr  = __ AddP(no_base, tls, __ ConX(buffer_offset));
4079   Node* index_adr   = __ AddP(no_base, tls, __ ConX(index_offset));
4080 
4081   // Now some of the values
4082   Node* marking = __ load(__ ctrl(), marking_adr, TypeInt::INT, active_type, Compile::AliasIdxRaw);
4083 
4084   // if (!marking)
4085   __ if_then(marking, BoolTest::ne, zero, unlikely); {
4086     BasicType index_bt = TypeX_X->basic_type();
4087     assert(sizeof(size_t) == type2aelembytes(index_bt), "Loading G1 SATBMarkQueue::_index with wrong size.");
4088     Node* index   = __ load(__ ctrl(), index_adr, TypeX_X, index_bt, Compile::AliasIdxRaw);
4089 
4090     if (do_load) {
4091       // load original value
4092       // alias_idx correct??
4093       pre_val = __ load(__ ctrl(), adr, val_type, bt, alias_idx);
4094     }
4095 
4096     // if (pre_val != NULL)
4097     __ if_then(pre_val, BoolTest::ne, null()); {
4098       Node* buffer  = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
4099 
4100       // is the queue for this thread full?
4101       __ if_then(index, BoolTest::ne, zeroX, likely); {
4102 
4103         // decrement the index
4104         Node* next_index = _gvn.transform(new SubXNode(index, __ ConX(sizeof(intptr_t))));
4105 
4106         // Now get the buffer location we will log the previous value into and store it
4107         Node *log_addr = __ AddP(no_base, buffer, next_index);
4108         __ store(__ ctrl(), log_addr, pre_val, T_OBJECT, Compile::AliasIdxRaw, MemNode::unordered);
4109         // update the index
4110         __ store(__ ctrl(), index_adr, next_index, index_bt, Compile::AliasIdxRaw, MemNode::unordered);
4111 
4112       } __ else_(); {
4113 
4114         // logging buffer is full, call the runtime
4115         const TypeFunc *tf = OptoRuntime::g1_wb_pre_Type();
4116         __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_pre), "g1_wb_pre", pre_val, tls);
4117       } __ end_if();  // (!index)
4118     } __ end_if();  // (pre_val != NULL)
4119   } __ end_if();  // (!marking)
4120 
4121   // Final sync IdealKit and GraphKit.
4122   final_sync(ideal);
4123 }
4124 
4125 /*
4126  * G1 similar to any GC with a Young Generation requires a way to keep track of
4127  * references from Old Generation to Young Generation to make sure all live
4128  * objects are found. G1 also requires to keep track of object references
4129  * between different regions to enable evacuation of old regions, which is done
4130  * as part of mixed collections. References are tracked in remembered sets and
4131  * is continuously updated as reference are written to with the help of the
4132  * post-barrier.
4133  *
4134  * To reduce the number of updates to the remembered set the post-barrier
4135  * filters updates to fields in objects located in the Young Generation,
4136  * the same region as the reference, when the NULL is being written or
4137  * if the card is already marked as dirty by an earlier write.
4138  *
4139  * Under certain circumstances it is possible to avoid generating the
4140  * post-barrier completely if it is possible during compile time to prove
4141  * the object is newly allocated and that no safepoint exists between the
4142  * allocation and the store.
4143  *
4144  * In the case of slow allocation the allocation code must handle the barrier
4145  * as part of the allocation in the case the allocated object is not located
4146  * in the nursery, this would happen for humongous objects. This is similar to
4147  * how CMS is required to handle this case, see the comments for the method
4148  * CollectedHeap::new_store_pre_barrier and OptoRuntime::new_store_pre_barrier.
4149  * A deferred card mark is required for these objects and handled in the above
4150  * mentioned methods.
4151  *
4152  * Returns true if the post barrier can be removed
4153  */
4154 bool GraphKit::g1_can_remove_post_barrier(PhaseTransform* phase, Node* store,
4155                                           Node* adr) {
4156   intptr_t      offset = 0;
4157   Node*         base   = AddPNode::Ideal_base_and_offset(adr, phase, offset);
4158   AllocateNode* alloc  = AllocateNode::Ideal_allocation(base, phase);
4159 
4160   if (offset == Type::OffsetBot) {
4161     return false; // cannot unalias unless there are precise offsets
4162   }
4163 
4164   if (alloc == NULL) {
4165      return false; // No allocation found
4166   }
4167 
4168   // Start search from Store node
4169   Node* mem = store->in(MemNode::Control);
4170   if (mem->is_Proj() && mem->in(0)->is_Initialize()) {
4171 
4172     InitializeNode* st_init = mem->in(0)->as_Initialize();
4173     AllocateNode*  st_alloc = st_init->allocation();
4174 
4175     // Make sure we are looking at the same allocation
4176     if (alloc == st_alloc) {
4177       return true;
4178     }
4179   }
4180 
4181   return false;
4182 }
4183 
4184 //
4185 // Update the card table and add card address to the queue
4186 //
4187 void GraphKit::g1_mark_card(IdealKit& ideal,
4188                             Node* card_adr,
4189                             Node* oop_store,
4190                             uint oop_alias_idx,
4191                             Node* index,
4192                             Node* index_adr,
4193                             Node* buffer,
4194                             const TypeFunc* tf) {
4195 
4196   Node* zero  = __ ConI(0);
4197   Node* zeroX = __ ConX(0);
4198   Node* no_base = __ top();
4199   BasicType card_bt = T_BYTE;
4200   // Smash zero into card. MUST BE ORDERED WRT TO STORE
4201   __ storeCM(__ ctrl(), card_adr, zero, oop_store, oop_alias_idx, card_bt, Compile::AliasIdxRaw);
4202 
4203   //  Now do the queue work
4204   __ if_then(index, BoolTest::ne, zeroX); {
4205 
4206     Node* next_index = _gvn.transform(new SubXNode(index, __ ConX(sizeof(intptr_t))));
4207     Node* log_addr = __ AddP(no_base, buffer, next_index);
4208 
4209     // Order, see storeCM.
4210     __ store(__ ctrl(), log_addr, card_adr, T_ADDRESS, Compile::AliasIdxRaw, MemNode::unordered);
4211     __ store(__ ctrl(), index_adr, next_index, TypeX_X->basic_type(), Compile::AliasIdxRaw, MemNode::unordered);
4212 
4213   } __ else_(); {
4214     __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_post), "g1_wb_post", card_adr, __ thread());
4215   } __ end_if();
4216 
4217 }
4218 
4219 void GraphKit::g1_write_barrier_post(Node* oop_store,
4220                                      Node* obj,
4221                                      Node* adr,
4222                                      uint alias_idx,
4223                                      Node* val,
4224                                      BasicType bt,
4225                                      bool use_precise) {
4226   // If we are writing a NULL then we need no post barrier
4227 
4228   if (val != NULL && val->is_Con() && val->bottom_type() == TypePtr::NULL_PTR) {
4229     // Must be NULL
4230     const Type* t = val->bottom_type();
4231     assert(t == Type::TOP || t == TypePtr::NULL_PTR, "must be NULL");
4232     // No post barrier if writing NULLx
4233     return;
4234   }
4235 
4236   if (use_ReduceInitialCardMarks() && obj == just_allocated_object(control())) {
4237     // We can skip marks on a freshly-allocated object in Eden.
4238     // Keep this code in sync with new_store_pre_barrier() in runtime.cpp.
4239     // That routine informs GC to take appropriate compensating steps,
4240     // upon a slow-path allocation, so as to make this card-mark
4241     // elision safe.
4242     return;
4243   }
4244 
4245   if (use_ReduceInitialCardMarks()
4246       && g1_can_remove_post_barrier(&_gvn, oop_store, adr)) {
4247     return;
4248   }
4249 
4250   if (!use_precise) {
4251     // All card marks for a (non-array) instance are in one place:
4252     adr = obj;
4253   }
4254   // (Else it's an array (or unknown), and we want more precise card marks.)
4255   assert(adr != NULL, "");
4256 
4257   IdealKit ideal(this, true);
4258 
4259   Node* tls = __ thread(); // ThreadLocalStorage
4260 
4261   Node* no_base = __ top();
4262   float likely  = PROB_LIKELY(0.999);
4263   float unlikely  = PROB_UNLIKELY(0.999);
4264   Node* young_card = __ ConI((jint)G1SATBCardTableModRefBS::g1_young_card_val());
4265   Node* dirty_card = __ ConI((jint)CardTableModRefBS::dirty_card_val());
4266   Node* zeroX = __ ConX(0);
4267 
4268   // Get the alias_index for raw card-mark memory
4269   const TypePtr* card_type = TypeRawPtr::BOTTOM;
4270 
4271   const TypeFunc *tf = OptoRuntime::g1_wb_post_Type();
4272 
4273   // Offsets into the thread
4274   const int index_offset  = in_bytes(JavaThread::dirty_card_queue_offset() +
4275                                      DirtyCardQueue::byte_offset_of_index());
4276   const int buffer_offset = in_bytes(JavaThread::dirty_card_queue_offset() +
4277                                      DirtyCardQueue::byte_offset_of_buf());
4278 
4279   // Pointers into the thread
4280 
4281   Node* buffer_adr = __ AddP(no_base, tls, __ ConX(buffer_offset));
4282   Node* index_adr =  __ AddP(no_base, tls, __ ConX(index_offset));
4283 
4284   // Now some values
4285   // Use ctrl to avoid hoisting these values past a safepoint, which could
4286   // potentially reset these fields in the JavaThread.
4287   Node* index  = __ load(__ ctrl(), index_adr, TypeX_X, TypeX_X->basic_type(), Compile::AliasIdxRaw);
4288   Node* buffer = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
4289 
4290   // Convert the store obj pointer to an int prior to doing math on it
4291   // Must use ctrl to prevent "integerized oop" existing across safepoint
4292   Node* cast =  __ CastPX(__ ctrl(), adr);
4293 
4294   // Divide pointer by card size
4295   Node* card_offset = __ URShiftX( cast, __ ConI(CardTableModRefBS::card_shift) );
4296 
4297   // Combine card table base and card offset
4298   Node* card_adr = __ AddP(no_base, byte_map_base_node(), card_offset );
4299 
4300   // If we know the value being stored does it cross regions?
4301 
4302   if (val != NULL) {
4303     // Does the store cause us to cross regions?
4304 
4305     // Should be able to do an unsigned compare of region_size instead of
4306     // and extra shift. Do we have an unsigned compare??
4307     // Node* region_size = __ ConI(1 << HeapRegion::LogOfHRGrainBytes);
4308     Node* xor_res =  __ URShiftX ( __ XorX( cast,  __ CastPX(__ ctrl(), val)), __ ConI(HeapRegion::LogOfHRGrainBytes));
4309 
4310     // if (xor_res == 0) same region so skip
4311     __ if_then(xor_res, BoolTest::ne, zeroX); {
4312 
4313       // No barrier if we are storing a NULL
4314       __ if_then(val, BoolTest::ne, null(), unlikely); {
4315 
4316         // Ok must mark the card if not already dirty
4317 
4318         // load the original value of the card
4319         Node* card_val = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
4320 
4321         __ if_then(card_val, BoolTest::ne, young_card); {
4322           sync_kit(ideal);
4323           // Use Op_MemBarVolatile to achieve the effect of a StoreLoad barrier.
4324           insert_mem_bar(Op_MemBarVolatile, oop_store);
4325           __ sync_kit(this);
4326 
4327           Node* card_val_reload = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
4328           __ if_then(card_val_reload, BoolTest::ne, dirty_card); {
4329             g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
4330           } __ end_if();
4331         } __ end_if();
4332       } __ end_if();
4333     } __ end_if();
4334   } else {
4335     // The Object.clone() intrinsic uses this path if !ReduceInitialCardMarks.
4336     // We don't need a barrier here if the destination is a newly allocated object
4337     // in Eden. Otherwise, GC verification breaks because we assume that cards in Eden
4338     // are set to 'g1_young_gen' (see G1SATBCardTableModRefBS::verify_g1_young_region()).
4339     assert(!use_ReduceInitialCardMarks(), "can only happen with card marking");
4340     Node* card_val = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
4341     __ if_then(card_val, BoolTest::ne, young_card); {
4342       g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
4343     } __ end_if();
4344   }
4345 
4346   // Final sync IdealKit and GraphKit.
4347   final_sync(ideal);
4348 }
4349 #undef __
4350 
4351 
4352 Node* GraphKit::load_String_length(Node* ctrl, Node* str) {
4353   Node* len = load_array_length(load_String_value(ctrl, str));
4354   Node* coder = load_String_coder(ctrl, str);
4355   // Divide length by 2 if coder is UTF16
4356   return _gvn.transform(new RShiftINode(len, coder));
4357 }
4358 
4359 Node* GraphKit::load_String_value(Node* ctrl, Node* str) {
4360   int value_offset = java_lang_String::value_offset_in_bytes();
4361   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4362                                                      false, NULL, Type::Offset(0));
4363   const TypePtr* value_field_type = string_type->add_offset(value_offset);
4364   const TypeAryPtr* value_type = TypeAryPtr::make(TypePtr::NotNull,
4365                                                   TypeAry::make(TypeInt::BYTE, TypeInt::POS),
4366                                                   ciTypeArrayKlass::make(T_BYTE), true, Type::Offset(0));
4367   int value_field_idx = C->get_alias_index(value_field_type);
4368   Node* load = make_load(ctrl, basic_plus_adr(str, str, value_offset),
4369                          value_type, T_OBJECT, value_field_idx, MemNode::unordered);
4370   // String.value field is known to be @Stable.
4371   if (UseImplicitStableValues) {
4372     load = cast_array_to_stable(load, value_type);
4373   }
4374   return load;
4375 }
4376 
4377 Node* GraphKit::load_String_coder(Node* ctrl, Node* str) {
4378   if (!CompactStrings) {
4379     return intcon(java_lang_String::CODER_UTF16);
4380   }
4381   int coder_offset = java_lang_String::coder_offset_in_bytes();
4382   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4383                                                      false, NULL, Type::Offset(0));
4384   const TypePtr* coder_field_type = string_type->add_offset(coder_offset);
4385   int coder_field_idx = C->get_alias_index(coder_field_type);
4386   return make_load(ctrl, basic_plus_adr(str, str, coder_offset),
4387                    TypeInt::BYTE, T_BYTE, coder_field_idx, MemNode::unordered);
4388 }
4389 
4390 void GraphKit::store_String_value(Node* ctrl, Node* str, Node* value) {
4391   int value_offset = java_lang_String::value_offset_in_bytes();
4392   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4393                                                      false, NULL, Type::Offset(0));
4394   const TypePtr* value_field_type = string_type->add_offset(value_offset);
4395   store_oop_to_object(ctrl, str,  basic_plus_adr(str, value_offset), value_field_type,
4396       value, TypeAryPtr::BYTES, T_OBJECT, MemNode::unordered);
4397 }
4398 
4399 void GraphKit::store_String_coder(Node* ctrl, Node* str, Node* value) {
4400   int coder_offset = java_lang_String::coder_offset_in_bytes();
4401   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4402                                                      false, NULL, Type::Offset(0));
4403   const TypePtr* coder_field_type = string_type->add_offset(coder_offset);
4404   int coder_field_idx = C->get_alias_index(coder_field_type);
4405   store_to_memory(ctrl, basic_plus_adr(str, coder_offset),
4406                   value, T_BYTE, coder_field_idx, MemNode::unordered);
4407 }
4408 
4409 // Capture src and dst memory state with a MergeMemNode
4410 Node* GraphKit::capture_memory(const TypePtr* src_type, const TypePtr* dst_type) {
4411   if (src_type == dst_type) {
4412     // Types are equal, we don't need a MergeMemNode
4413     return memory(src_type);
4414   }
4415   MergeMemNode* merge = MergeMemNode::make(map()->memory());
4416   record_for_igvn(merge); // fold it up later, if possible
4417   int src_idx = C->get_alias_index(src_type);
4418   int dst_idx = C->get_alias_index(dst_type);
4419   merge->set_memory_at(src_idx, memory(src_idx));
4420   merge->set_memory_at(dst_idx, memory(dst_idx));
4421   return merge;
4422 }
4423 
4424 Node* GraphKit::compress_string(Node* src, const TypeAryPtr* src_type, Node* dst, Node* count) {
4425   assert(Matcher::match_rule_supported(Op_StrCompressedCopy), "Intrinsic not supported");
4426   assert(src_type == TypeAryPtr::BYTES || src_type == TypeAryPtr::CHARS, "invalid source type");
4427   // If input and output memory types differ, capture both states to preserve
4428   // the dependency between preceding and subsequent loads/stores.
4429   // For example, the following program:
4430   //  StoreB
4431   //  compress_string
4432   //  LoadB
4433   // has this memory graph (use->def):
4434   //  LoadB -> compress_string -> CharMem
4435   //             ... -> StoreB -> ByteMem
4436   // The intrinsic hides the dependency between LoadB and StoreB, causing
4437   // the load to read from memory not containing the result of the StoreB.
4438   // The correct memory graph should look like this:
4439   //  LoadB -> compress_string -> MergeMem(CharMem, StoreB(ByteMem))
4440   Node* mem = capture_memory(src_type, TypeAryPtr::BYTES);
4441   StrCompressedCopyNode* str = new StrCompressedCopyNode(control(), mem, src, dst, count);
4442   Node* res_mem = _gvn.transform(new SCMemProjNode(str));
4443   set_memory(res_mem, TypeAryPtr::BYTES);
4444   return str;
4445 }
4446 
4447 void GraphKit::inflate_string(Node* src, Node* dst, const TypeAryPtr* dst_type, Node* count) {
4448   assert(Matcher::match_rule_supported(Op_StrInflatedCopy), "Intrinsic not supported");
4449   assert(dst_type == TypeAryPtr::BYTES || dst_type == TypeAryPtr::CHARS, "invalid dest type");
4450   // Capture src and dst memory (see comment in 'compress_string').
4451   Node* mem = capture_memory(TypeAryPtr::BYTES, dst_type);
4452   StrInflatedCopyNode* str = new StrInflatedCopyNode(control(), mem, src, dst, count);
4453   set_memory(_gvn.transform(str), dst_type);
4454 }
4455 
4456 void GraphKit::inflate_string_slow(Node* src, Node* dst, Node* start, Node* count) {
4457   /**
4458    * int i_char = start;
4459    * for (int i_byte = 0; i_byte < count; i_byte++) {
4460    *   dst[i_char++] = (char)(src[i_byte] & 0xff);
4461    * }
4462    */
4463   add_predicate();
4464   RegionNode* head = new RegionNode(3);
4465   head->init_req(1, control());
4466   gvn().set_type(head, Type::CONTROL);
4467   record_for_igvn(head);
4468 
4469   Node* i_byte = new PhiNode(head, TypeInt::INT);
4470   i_byte->init_req(1, intcon(0));
4471   gvn().set_type(i_byte, TypeInt::INT);
4472   record_for_igvn(i_byte);
4473 
4474   Node* i_char = new PhiNode(head, TypeInt::INT);
4475   i_char->init_req(1, start);
4476   gvn().set_type(i_char, TypeInt::INT);
4477   record_for_igvn(i_char);
4478 
4479   Node* mem = PhiNode::make(head, memory(TypeAryPtr::BYTES), Type::MEMORY, TypeAryPtr::BYTES);
4480   gvn().set_type(mem, Type::MEMORY);
4481   record_for_igvn(mem);
4482   set_control(head);
4483   set_memory(mem, TypeAryPtr::BYTES);
4484   Node* ch = load_array_element(control(), src, i_byte, TypeAryPtr::BYTES);
4485   Node* st = store_to_memory(control(), array_element_address(dst, i_char, T_BYTE),
4486                              AndI(ch, intcon(0xff)), T_CHAR, TypeAryPtr::BYTES, MemNode::unordered,
4487                              false, false, true /* mismatched */);
4488 
4489   IfNode* iff = create_and_map_if(head, Bool(CmpI(i_byte, count), BoolTest::lt), PROB_FAIR, COUNT_UNKNOWN);
4490   head->init_req(2, IfTrue(iff));
4491   mem->init_req(2, st);
4492   i_byte->init_req(2, AddI(i_byte, intcon(1)));
4493   i_char->init_req(2, AddI(i_char, intcon(2)));
4494 
4495   set_control(IfFalse(iff));
4496   set_memory(st, TypeAryPtr::BYTES);
4497 }
4498 
4499 Node* GraphKit::make_constant_from_field(ciField* field, Node* obj) {
4500   if (!field->is_constant()) {
4501     return NULL; // Field not marked as constant.
4502   }
4503   ciInstance* holder = NULL;
4504   if (!field->is_static()) {
4505     ciObject* const_oop = obj->bottom_type()->is_oopptr()->const_oop();
4506     if (const_oop != NULL && const_oop->is_instance()) {
4507       holder = const_oop->as_instance();
4508     }
4509   }
4510   const Type* con_type = Type::make_constant_from_field(field, holder, field->layout_type(),
4511                                                         /*is_unsigned_load=*/false);
4512   if (con_type != NULL) {
4513     Node* con = makecon(con_type);
4514     if (field->layout_type() == T_VALUETYPE) {
4515       // Load value type from constant oop
4516       con = ValueTypeNode::make(gvn(), map()->memory(), con);
4517     }
4518     return con;
4519   }
4520   return NULL;
4521 }
4522 
4523 Node* GraphKit::cast_array_to_stable(Node* ary, const TypeAryPtr* ary_type) {
4524   // Reify the property as a CastPP node in Ideal graph to comply with monotonicity
4525   // assumption of CCP analysis.
4526   return _gvn.transform(new CastPPNode(ary, ary_type->cast_to_stable(true)));
4527 }