1 /*
   2  * Copyright (c) 2001, 2017, 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, PhaseGVN* gvn)
  53   : Phase(Phase::Parser),
  54     _env(C->env()),
  55     _gvn((gvn != NULL) ? *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 #ifdef ASSERT
  61   if (_gvn.is_IterGVN() != NULL) {
  62     assert(_gvn.is_IterGVN()->delay_transform(), "Transformation must be delayed if IterGVN is used");
  63     // Save the initial size of _for_igvn worklist for verification (see ~GraphKit)
  64     _worklist_size = _gvn.C->for_igvn()->size();
  65   }
  66 #endif
  67 }
  68 
  69 // Private constructor for parser.
  70 GraphKit::GraphKit()
  71   : Phase(Phase::Parser),
  72     _env(C->env()),
  73     _gvn(*C->initial_gvn())
  74 {
  75   _exceptions = NULL;
  76   set_map(NULL);
  77   debug_only(_sp = -99);
  78   debug_only(set_bci(-99));
  79 }
  80 
  81 
  82 
  83 //---------------------------clean_stack---------------------------------------
  84 // Clear away rubbish from the stack area of the JVM state.
  85 // This destroys any arguments that may be waiting on the stack.
  86 void GraphKit::clean_stack(int from_sp) {
  87   SafePointNode* map      = this->map();
  88   JVMState*      jvms     = this->jvms();
  89   int            stk_size = jvms->stk_size();
  90   int            stkoff   = jvms->stkoff();
  91   Node*          top      = this->top();
  92   for (int i = from_sp; i < stk_size; i++) {
  93     if (map->in(stkoff + i) != top) {
  94       map->set_req(stkoff + i, top);
  95     }
  96   }
  97 }
  98 
  99 
 100 //--------------------------------sync_jvms-----------------------------------
 101 // Make sure our current jvms agrees with our parse state.
 102 JVMState* GraphKit::sync_jvms() const {
 103   JVMState* jvms = this->jvms();
 104   jvms->set_bci(bci());       // Record the new bci in the JVMState
 105   jvms->set_sp(sp());         // Record the new sp in the JVMState
 106   assert(jvms_in_sync(), "jvms is now in sync");
 107   return jvms;
 108 }
 109 
 110 //--------------------------------sync_jvms_for_reexecute---------------------
 111 // Make sure our current jvms agrees with our parse state.  This version
 112 // uses the reexecute_sp for reexecuting bytecodes.
 113 JVMState* GraphKit::sync_jvms_for_reexecute() {
 114   JVMState* jvms = this->jvms();
 115   jvms->set_bci(bci());          // Record the new bci in the JVMState
 116   jvms->set_sp(reexecute_sp());  // Record the new sp in the JVMState
 117   return jvms;
 118 }
 119 
 120 #ifdef ASSERT
 121 bool GraphKit::jvms_in_sync() const {
 122   Parse* parse = is_Parse();
 123   if (parse == NULL) {
 124     if (bci() !=      jvms()->bci())          return false;
 125     if (sp()  != (int)jvms()->sp())           return false;
 126     return true;
 127   }
 128   if (jvms()->method() != parse->method())    return false;
 129   if (jvms()->bci()    != parse->bci())       return false;
 130   int jvms_sp = jvms()->sp();
 131   if (jvms_sp          != parse->sp())        return false;
 132   int jvms_depth = jvms()->depth();
 133   if (jvms_depth       != parse->depth())     return false;
 134   return true;
 135 }
 136 
 137 // Local helper checks for special internal merge points
 138 // used to accumulate and merge exception states.
 139 // They are marked by the region's in(0) edge being the map itself.
 140 // Such merge points must never "escape" into the parser at large,
 141 // until they have been handed to gvn.transform.
 142 static bool is_hidden_merge(Node* reg) {
 143   if (reg == NULL)  return false;
 144   if (reg->is_Phi()) {
 145     reg = reg->in(0);
 146     if (reg == NULL)  return false;
 147   }
 148   return reg->is_Region() && reg->in(0) != NULL && reg->in(0)->is_Root();
 149 }
 150 
 151 void GraphKit::verify_map() const {
 152   if (map() == NULL)  return;  // null map is OK
 153   assert(map()->req() <= jvms()->endoff(), "no extra garbage on map");
 154   assert(!map()->has_exceptions(),    "call add_exception_states_from 1st");
 155   assert(!is_hidden_merge(control()), "call use_exception_state, not set_map");
 156 }
 157 
 158 void GraphKit::verify_exception_state(SafePointNode* ex_map) {
 159   assert(ex_map->next_exception() == NULL, "not already part of a chain");
 160   assert(has_saved_ex_oop(ex_map), "every exception state has an ex_oop");
 161 }
 162 #endif
 163 
 164 //---------------------------stop_and_kill_map---------------------------------
 165 // Set _map to NULL, signalling a stop to further bytecode execution.
 166 // First smash the current map's control to a constant, to mark it dead.
 167 void GraphKit::stop_and_kill_map() {
 168   SafePointNode* dead_map = stop();
 169   if (dead_map != NULL) {
 170     dead_map->disconnect_inputs(NULL, C); // Mark the map as killed.
 171     assert(dead_map->is_killed(), "must be so marked");
 172   }
 173 }
 174 
 175 
 176 //--------------------------------stopped--------------------------------------
 177 // Tell if _map is NULL, or control is top.
 178 bool GraphKit::stopped() {
 179   if (map() == NULL)           return true;
 180   else if (control() == top()) return true;
 181   else                         return false;
 182 }
 183 
 184 
 185 //-----------------------------has_ex_handler----------------------------------
 186 // Tell if this method or any caller method has exception handlers.
 187 bool GraphKit::has_ex_handler() {
 188   for (JVMState* jvmsp = jvms(); jvmsp != NULL; jvmsp = jvmsp->caller()) {
 189     if (jvmsp->has_method() && jvmsp->method()->has_exception_handlers()) {
 190       return true;
 191     }
 192   }
 193   return false;
 194 }
 195 
 196 //------------------------------save_ex_oop------------------------------------
 197 // Save an exception without blowing stack contents or other JVM state.
 198 void GraphKit::set_saved_ex_oop(SafePointNode* ex_map, Node* ex_oop) {
 199   assert(!has_saved_ex_oop(ex_map), "clear ex-oop before setting again");
 200   ex_map->add_req(ex_oop);
 201   debug_only(verify_exception_state(ex_map));
 202 }
 203 
 204 inline static Node* common_saved_ex_oop(SafePointNode* ex_map, bool clear_it) {
 205   assert(GraphKit::has_saved_ex_oop(ex_map), "ex_oop must be there");
 206   Node* ex_oop = ex_map->in(ex_map->req()-1);
 207   if (clear_it)  ex_map->del_req(ex_map->req()-1);
 208   return ex_oop;
 209 }
 210 
 211 //-----------------------------saved_ex_oop------------------------------------
 212 // Recover a saved exception from its map.
 213 Node* GraphKit::saved_ex_oop(SafePointNode* ex_map) {
 214   return common_saved_ex_oop(ex_map, false);
 215 }
 216 
 217 //--------------------------clear_saved_ex_oop---------------------------------
 218 // Erase a previously saved exception from its map.
 219 Node* GraphKit::clear_saved_ex_oop(SafePointNode* ex_map) {
 220   return common_saved_ex_oop(ex_map, true);
 221 }
 222 
 223 #ifdef ASSERT
 224 //---------------------------has_saved_ex_oop----------------------------------
 225 // Erase a previously saved exception from its map.
 226 bool GraphKit::has_saved_ex_oop(SafePointNode* ex_map) {
 227   return ex_map->req() == ex_map->jvms()->endoff()+1;
 228 }
 229 #endif
 230 
 231 //-------------------------make_exception_state--------------------------------
 232 // Turn the current JVM state into an exception state, appending the ex_oop.
 233 SafePointNode* GraphKit::make_exception_state(Node* ex_oop) {
 234   sync_jvms();
 235   SafePointNode* ex_map = stop();  // do not manipulate this map any more
 236   set_saved_ex_oop(ex_map, ex_oop);
 237   return ex_map;
 238 }
 239 
 240 
 241 //--------------------------add_exception_state--------------------------------
 242 // Add an exception to my list of exceptions.
 243 void GraphKit::add_exception_state(SafePointNode* ex_map) {
 244   if (ex_map == NULL || ex_map->control() == top()) {
 245     return;
 246   }
 247 #ifdef ASSERT
 248   verify_exception_state(ex_map);
 249   if (has_exceptions()) {
 250     assert(ex_map->jvms()->same_calls_as(_exceptions->jvms()), "all collected exceptions must come from the same place");
 251   }
 252 #endif
 253 
 254   // If there is already an exception of exactly this type, merge with it.
 255   // In particular, null-checks and other low-level exceptions common up here.
 256   Node*       ex_oop  = saved_ex_oop(ex_map);
 257   const Type* ex_type = _gvn.type(ex_oop);
 258   if (ex_oop == top()) {
 259     // No action needed.
 260     return;
 261   }
 262   assert(ex_type->isa_instptr(), "exception must be an instance");
 263   for (SafePointNode* e2 = _exceptions; e2 != NULL; e2 = e2->next_exception()) {
 264     const Type* ex_type2 = _gvn.type(saved_ex_oop(e2));
 265     // We check sp also because call bytecodes can generate exceptions
 266     // both before and after arguments are popped!
 267     if (ex_type2 == ex_type
 268         && e2->_jvms->sp() == ex_map->_jvms->sp()) {
 269       combine_exception_states(ex_map, e2);
 270       return;
 271     }
 272   }
 273 
 274   // No pre-existing exception of the same type.  Chain it on the list.
 275   push_exception_state(ex_map);
 276 }
 277 
 278 //-----------------------add_exception_states_from-----------------------------
 279 void GraphKit::add_exception_states_from(JVMState* jvms) {
 280   SafePointNode* ex_map = jvms->map()->next_exception();
 281   if (ex_map != NULL) {
 282     jvms->map()->set_next_exception(NULL);
 283     for (SafePointNode* next_map; ex_map != NULL; ex_map = next_map) {
 284       next_map = ex_map->next_exception();
 285       ex_map->set_next_exception(NULL);
 286       add_exception_state(ex_map);
 287     }
 288   }
 289 }
 290 
 291 //-----------------------transfer_exceptions_into_jvms-------------------------
 292 JVMState* GraphKit::transfer_exceptions_into_jvms() {
 293   if (map() == NULL) {
 294     // We need a JVMS to carry the exceptions, but the map has gone away.
 295     // Create a scratch JVMS, cloned from any of the exception states...
 296     if (has_exceptions()) {
 297       _map = _exceptions;
 298       _map = clone_map();
 299       _map->set_next_exception(NULL);
 300       clear_saved_ex_oop(_map);
 301       debug_only(verify_map());
 302     } else {
 303       // ...or created from scratch
 304       JVMState* jvms = new (C) JVMState(_method, NULL);
 305       jvms->set_bci(_bci);
 306       jvms->set_sp(_sp);
 307       jvms->set_map(new SafePointNode(TypeFunc::Parms, jvms));
 308       set_jvms(jvms);
 309       for (uint i = 0; i < map()->req(); i++)  map()->init_req(i, top());
 310       set_all_memory(top());
 311       while (map()->req() < jvms->endoff())  map()->add_req(top());
 312     }
 313     // (This is a kludge, in case you didn't notice.)
 314     set_control(top());
 315   }
 316   JVMState* jvms = sync_jvms();
 317   assert(!jvms->map()->has_exceptions(), "no exceptions on this map yet");
 318   jvms->map()->set_next_exception(_exceptions);
 319   _exceptions = NULL;   // done with this set of exceptions
 320   return jvms;
 321 }
 322 
 323 static inline void add_n_reqs(Node* dstphi, Node* srcphi) {
 324   assert(is_hidden_merge(dstphi), "must be a special merge node");
 325   assert(is_hidden_merge(srcphi), "must be a special merge node");
 326   uint limit = srcphi->req();
 327   for (uint i = PhiNode::Input; i < limit; i++) {
 328     dstphi->add_req(srcphi->in(i));
 329   }
 330 }
 331 static inline void add_one_req(Node* dstphi, Node* src) {
 332   assert(is_hidden_merge(dstphi), "must be a special merge node");
 333   assert(!is_hidden_merge(src), "must not be a special merge node");
 334   dstphi->add_req(src);
 335 }
 336 
 337 //-----------------------combine_exception_states------------------------------
 338 // This helper function combines exception states by building phis on a
 339 // specially marked state-merging region.  These regions and phis are
 340 // untransformed, and can build up gradually.  The region is marked by
 341 // having a control input of its exception map, rather than NULL.  Such
 342 // regions do not appear except in this function, and in use_exception_state.
 343 void GraphKit::combine_exception_states(SafePointNode* ex_map, SafePointNode* phi_map) {
 344   if (failing())  return;  // dying anyway...
 345   JVMState* ex_jvms = ex_map->_jvms;
 346   assert(ex_jvms->same_calls_as(phi_map->_jvms), "consistent call chains");
 347   assert(ex_jvms->stkoff() == phi_map->_jvms->stkoff(), "matching locals");
 348   assert(ex_jvms->sp() == phi_map->_jvms->sp(), "matching stack sizes");
 349   assert(ex_jvms->monoff() == phi_map->_jvms->monoff(), "matching JVMS");
 350   assert(ex_jvms->scloff() == phi_map->_jvms->scloff(), "matching scalar replaced objects");
 351   assert(ex_map->req() == phi_map->req(), "matching maps");
 352   uint tos = ex_jvms->stkoff() + ex_jvms->sp();
 353   Node*         hidden_merge_mark = root();
 354   Node*         region  = phi_map->control();
 355   MergeMemNode* phi_mem = phi_map->merged_memory();
 356   MergeMemNode* ex_mem  = ex_map->merged_memory();
 357   if (region->in(0) != hidden_merge_mark) {
 358     // The control input is not (yet) a specially-marked region in phi_map.
 359     // Make it so, and build some phis.
 360     region = new RegionNode(2);
 361     _gvn.set_type(region, Type::CONTROL);
 362     region->set_req(0, hidden_merge_mark);  // marks an internal ex-state
 363     region->init_req(1, phi_map->control());
 364     phi_map->set_control(region);
 365     Node* io_phi = PhiNode::make(region, phi_map->i_o(), Type::ABIO);
 366     record_for_igvn(io_phi);
 367     _gvn.set_type(io_phi, Type::ABIO);
 368     phi_map->set_i_o(io_phi);
 369     for (MergeMemStream mms(phi_mem); mms.next_non_empty(); ) {
 370       Node* m = mms.memory();
 371       Node* m_phi = PhiNode::make(region, m, Type::MEMORY, mms.adr_type(C));
 372       record_for_igvn(m_phi);
 373       _gvn.set_type(m_phi, Type::MEMORY);
 374       mms.set_memory(m_phi);
 375     }
 376   }
 377 
 378   // Either or both of phi_map and ex_map might already be converted into phis.
 379   Node* ex_control = ex_map->control();
 380   // if there is special marking on ex_map also, we add multiple edges from src
 381   bool add_multiple = (ex_control->in(0) == hidden_merge_mark);
 382   // how wide was the destination phi_map, originally?
 383   uint orig_width = region->req();
 384 
 385   if (add_multiple) {
 386     add_n_reqs(region, ex_control);
 387     add_n_reqs(phi_map->i_o(), ex_map->i_o());
 388   } else {
 389     // ex_map has no merges, so we just add single edges everywhere
 390     add_one_req(region, ex_control);
 391     add_one_req(phi_map->i_o(), ex_map->i_o());
 392   }
 393   for (MergeMemStream mms(phi_mem, ex_mem); mms.next_non_empty2(); ) {
 394     if (mms.is_empty()) {
 395       // get a copy of the base memory, and patch some inputs into it
 396       const TypePtr* adr_type = mms.adr_type(C);
 397       Node* phi = mms.force_memory()->as_Phi()->slice_memory(adr_type);
 398       assert(phi->as_Phi()->region() == mms.base_memory()->in(0), "");
 399       mms.set_memory(phi);
 400       // Prepare to append interesting stuff onto the newly sliced phi:
 401       while (phi->req() > orig_width)  phi->del_req(phi->req()-1);
 402     }
 403     // Append stuff from ex_map:
 404     if (add_multiple) {
 405       add_n_reqs(mms.memory(), mms.memory2());
 406     } else {
 407       add_one_req(mms.memory(), mms.memory2());
 408     }
 409   }
 410   uint limit = ex_map->req();
 411   for (uint i = TypeFunc::Parms; i < limit; i++) {
 412     // Skip everything in the JVMS after tos.  (The ex_oop follows.)
 413     if (i == tos)  i = ex_jvms->monoff();
 414     Node* src = ex_map->in(i);
 415     Node* dst = phi_map->in(i);
 416     if (src != dst) {
 417       PhiNode* phi;
 418       if (dst->in(0) != region) {
 419         dst = phi = PhiNode::make(region, dst, _gvn.type(dst));
 420         record_for_igvn(phi);
 421         _gvn.set_type(phi, phi->type());
 422         phi_map->set_req(i, dst);
 423         // Prepare to append interesting stuff onto the new phi:
 424         while (dst->req() > orig_width)  dst->del_req(dst->req()-1);
 425       } else {
 426         assert(dst->is_Phi(), "nobody else uses a hidden region");
 427         phi = dst->as_Phi();
 428       }
 429       if (add_multiple && src->in(0) == ex_control) {
 430         // Both are phis.
 431         add_n_reqs(dst, src);
 432       } else {
 433         while (dst->req() < region->req())  add_one_req(dst, src);
 434       }
 435       const Type* srctype = _gvn.type(src);
 436       if (phi->type() != srctype) {
 437         const Type* dsttype = phi->type()->meet_speculative(srctype);
 438         if (phi->type() != dsttype) {
 439           phi->set_type(dsttype);
 440           _gvn.set_type(phi, dsttype);
 441         }
 442       }
 443     }
 444   }
 445   phi_map->merge_replaced_nodes_with(ex_map);
 446 }
 447 
 448 //--------------------------use_exception_state--------------------------------
 449 Node* GraphKit::use_exception_state(SafePointNode* phi_map) {
 450   if (failing()) { stop(); return top(); }
 451   Node* region = phi_map->control();
 452   Node* hidden_merge_mark = root();
 453   assert(phi_map->jvms()->map() == phi_map, "sanity: 1-1 relation");
 454   Node* ex_oop = clear_saved_ex_oop(phi_map);
 455   if (region->in(0) == hidden_merge_mark) {
 456     // Special marking for internal ex-states.  Process the phis now.
 457     region->set_req(0, region);  // now it's an ordinary region
 458     set_jvms(phi_map->jvms());   // ...so now we can use it as a map
 459     // Note: Setting the jvms also sets the bci and sp.
 460     set_control(_gvn.transform(region));
 461     uint tos = jvms()->stkoff() + sp();
 462     for (uint i = 1; i < tos; i++) {
 463       Node* x = phi_map->in(i);
 464       if (x->in(0) == region) {
 465         assert(x->is_Phi(), "expected a special phi");
 466         phi_map->set_req(i, _gvn.transform(x));
 467       }
 468     }
 469     for (MergeMemStream mms(merged_memory()); mms.next_non_empty(); ) {
 470       Node* x = mms.memory();
 471       if (x->in(0) == region) {
 472         assert(x->is_Phi(), "nobody else uses a hidden region");
 473         mms.set_memory(_gvn.transform(x));
 474       }
 475     }
 476     if (ex_oop->in(0) == region) {
 477       assert(ex_oop->is_Phi(), "expected a special phi");
 478       ex_oop = _gvn.transform(ex_oop);
 479     }
 480   } else {
 481     set_jvms(phi_map->jvms());
 482   }
 483 
 484   assert(!is_hidden_merge(phi_map->control()), "hidden ex. states cleared");
 485   assert(!is_hidden_merge(phi_map->i_o()), "hidden ex. states cleared");
 486   return ex_oop;
 487 }
 488 
 489 //---------------------------------java_bc-------------------------------------
 490 Bytecodes::Code GraphKit::java_bc() const {
 491   ciMethod* method = this->method();
 492   int       bci    = this->bci();
 493   if (method != NULL && bci != InvocationEntryBci)
 494     return method->java_code_at_bci(bci);
 495   else
 496     return Bytecodes::_illegal;
 497 }
 498 
 499 void GraphKit::uncommon_trap_if_should_post_on_exceptions(Deoptimization::DeoptReason reason,
 500                                                           bool must_throw) {
 501     // if the exception capability is set, then we will generate code
 502     // to check the JavaThread.should_post_on_exceptions flag to see
 503     // if we actually need to report exception events (for this
 504     // thread).  If we don't need to report exception events, we will
 505     // take the normal fast path provided by add_exception_events.  If
 506     // exception event reporting is enabled for this thread, we will
 507     // take the uncommon_trap in the BuildCutout below.
 508 
 509     // first must access the should_post_on_exceptions_flag in this thread's JavaThread
 510     Node* jthread = _gvn.transform(new ThreadLocalNode());
 511     Node* adr = basic_plus_adr(top(), jthread, in_bytes(JavaThread::should_post_on_exceptions_flag_offset()));
 512     Node* should_post_flag = make_load(control(), adr, TypeInt::INT, T_INT, Compile::AliasIdxRaw, MemNode::unordered);
 513 
 514     // Test the should_post_on_exceptions_flag vs. 0
 515     Node* chk = _gvn.transform( new CmpINode(should_post_flag, intcon(0)) );
 516     Node* tst = _gvn.transform( new BoolNode(chk, BoolTest::eq) );
 517 
 518     // Branch to slow_path if should_post_on_exceptions_flag was true
 519     { BuildCutout unless(this, tst, PROB_MAX);
 520       // Do not try anything fancy if we're notifying the VM on every throw.
 521       // Cf. case Bytecodes::_athrow in parse2.cpp.
 522       uncommon_trap(reason, Deoptimization::Action_none,
 523                     (ciKlass*)NULL, (char*)NULL, must_throw);
 524     }
 525 
 526 }
 527 
 528 //------------------------------builtin_throw----------------------------------
 529 void GraphKit::builtin_throw(Deoptimization::DeoptReason reason, Node* arg) {
 530   bool must_throw = true;
 531 
 532   if (env()->jvmti_can_post_on_exceptions()) {
 533     // check if we must post exception events, take uncommon trap if so
 534     uncommon_trap_if_should_post_on_exceptions(reason, must_throw);
 535     // here if should_post_on_exceptions is false
 536     // continue on with the normal codegen
 537   }
 538 
 539   // If this particular condition has not yet happened at this
 540   // bytecode, then use the uncommon trap mechanism, and allow for
 541   // a future recompilation if several traps occur here.
 542   // If the throw is hot, try to use a more complicated inline mechanism
 543   // which keeps execution inside the compiled code.
 544   bool treat_throw_as_hot = false;
 545   ciMethodData* md = method()->method_data();
 546 
 547   if (ProfileTraps) {
 548     if (too_many_traps(reason)) {
 549       treat_throw_as_hot = true;
 550     }
 551     // (If there is no MDO at all, assume it is early in
 552     // execution, and that any deopts are part of the
 553     // startup transient, and don't need to be remembered.)
 554 
 555     // Also, if there is a local exception handler, treat all throws
 556     // as hot if there has been at least one in this method.
 557     if (C->trap_count(reason) != 0
 558         && method()->method_data()->trap_count(reason) != 0
 559         && has_ex_handler()) {
 560         treat_throw_as_hot = true;
 561     }
 562   }
 563 
 564   // If this throw happens frequently, an uncommon trap might cause
 565   // a performance pothole.  If there is a local exception handler,
 566   // and if this particular bytecode appears to be deoptimizing often,
 567   // let us handle the throw inline, with a preconstructed instance.
 568   // Note:   If the deopt count has blown up, the uncommon trap
 569   // runtime is going to flush this nmethod, not matter what.
 570   if (treat_throw_as_hot
 571       && (!StackTraceInThrowable || OmitStackTraceInFastThrow)) {
 572     // If the throw is local, we use a pre-existing instance and
 573     // punt on the backtrace.  This would lead to a missing backtrace
 574     // (a repeat of 4292742) if the backtrace object is ever asked
 575     // for its backtrace.
 576     // Fixing this remaining case of 4292742 requires some flavor of
 577     // escape analysis.  Leave that for the future.
 578     ciInstance* ex_obj = NULL;
 579     switch (reason) {
 580     case Deoptimization::Reason_null_check:
 581       ex_obj = env()->NullPointerException_instance();
 582       break;
 583     case Deoptimization::Reason_div0_check:
 584       ex_obj = env()->ArithmeticException_instance();
 585       break;
 586     case Deoptimization::Reason_range_check:
 587       ex_obj = env()->ArrayIndexOutOfBoundsException_instance();
 588       break;
 589     case Deoptimization::Reason_class_check:
 590       if (java_bc() == Bytecodes::_aastore || java_bc() == Bytecodes::_vastore) {
 591         ex_obj = env()->ArrayStoreException_instance();
 592       } else {
 593         ex_obj = env()->ClassCastException_instance();
 594       }
 595       break;
 596     default:
 597       break;
 598     }
 599     if (failing()) { stop(); return; }  // exception allocation might fail
 600     if (ex_obj != NULL) {
 601       // Cheat with a preallocated exception object.
 602       if (C->log() != NULL)
 603         C->log()->elem("hot_throw preallocated='1' reason='%s'",
 604                        Deoptimization::trap_reason_name(reason));
 605       const TypeInstPtr* ex_con  = TypeInstPtr::make(ex_obj);
 606       Node*              ex_node = _gvn.transform(ConNode::make(ex_con));
 607 
 608       // Clear the detail message of the preallocated exception object.
 609       // Weblogic sometimes mutates the detail message of exceptions
 610       // using reflection.
 611       int offset = java_lang_Throwable::get_detailMessage_offset();
 612       const TypePtr* adr_typ = ex_con->add_offset(offset);
 613 
 614       Node *adr = basic_plus_adr(ex_node, ex_node, offset);
 615       const TypeOopPtr* val_type = TypeOopPtr::make_from_klass(env()->String_klass());
 616       // Conservatively release stores of object references.
 617       Node *store = store_oop_to_object(control(), ex_node, adr, adr_typ, null(), val_type, T_OBJECT, MemNode::release);
 618 
 619       add_exception_state(make_exception_state(ex_node));
 620       return;
 621     }
 622   }
 623 
 624   // %%% Maybe add entry to OptoRuntime which directly throws the exc.?
 625   // It won't be much cheaper than bailing to the interp., since we'll
 626   // have to pass up all the debug-info, and the runtime will have to
 627   // create the stack trace.
 628 
 629   // Usual case:  Bail to interpreter.
 630   // Reserve the right to recompile if we haven't seen anything yet.
 631 
 632   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? C->method() : NULL;
 633   Deoptimization::DeoptAction action = Deoptimization::Action_maybe_recompile;
 634   if (treat_throw_as_hot
 635       && (method()->method_data()->trap_recompiled_at(bci(), m)
 636           || C->too_many_traps(reason))) {
 637     // We cannot afford to take more traps here.  Suffer in the interpreter.
 638     if (C->log() != NULL)
 639       C->log()->elem("hot_throw preallocated='0' reason='%s' mcount='%d'",
 640                      Deoptimization::trap_reason_name(reason),
 641                      C->trap_count(reason));
 642     action = Deoptimization::Action_none;
 643   }
 644 
 645   // "must_throw" prunes the JVM state to include only the stack, if there
 646   // are no local exception handlers.  This should cut down on register
 647   // allocation time and code size, by drastically reducing the number
 648   // of in-edges on the call to the uncommon trap.
 649 
 650   uncommon_trap(reason, action, (ciKlass*)NULL, (char*)NULL, must_throw);
 651 }
 652 
 653 
 654 //----------------------------PreserveJVMState---------------------------------
 655 PreserveJVMState::PreserveJVMState(GraphKit* kit, bool clone_map) {
 656   debug_only(kit->verify_map());
 657   _kit    = kit;
 658   _map    = kit->map();   // preserve the map
 659   _sp     = kit->sp();
 660   kit->set_map(clone_map ? kit->clone_map() : NULL);
 661 #ifdef ASSERT
 662   _bci    = kit->bci();
 663   Parse* parser = kit->is_Parse();
 664   int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo();
 665   _block  = block;
 666 #endif
 667 }
 668 PreserveJVMState::~PreserveJVMState() {
 669   GraphKit* kit = _kit;
 670 #ifdef ASSERT
 671   assert(kit->bci() == _bci, "bci must not shift");
 672   Parse* parser = kit->is_Parse();
 673   int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo();
 674   assert(block == _block,    "block must not shift");
 675 #endif
 676   kit->set_map(_map);
 677   kit->set_sp(_sp);
 678 }
 679 
 680 
 681 //-----------------------------BuildCutout-------------------------------------
 682 BuildCutout::BuildCutout(GraphKit* kit, Node* p, float prob, float cnt)
 683   : PreserveJVMState(kit)
 684 {
 685   assert(p->is_Con() || p->is_Bool(), "test must be a bool");
 686   SafePointNode* outer_map = _map;   // preserved map is caller's
 687   SafePointNode* inner_map = kit->map();
 688   IfNode* iff = kit->create_and_map_if(outer_map->control(), p, prob, cnt);
 689   outer_map->set_control(kit->gvn().transform( new IfTrueNode(iff) ));
 690   inner_map->set_control(kit->gvn().transform( new IfFalseNode(iff) ));
 691 }
 692 BuildCutout::~BuildCutout() {
 693   GraphKit* kit = _kit;
 694   assert(kit->stopped(), "cutout code must stop, throw, return, etc.");
 695 }
 696 
 697 //---------------------------PreserveReexecuteState----------------------------
 698 PreserveReexecuteState::PreserveReexecuteState(GraphKit* kit) {
 699   assert(!kit->stopped(), "must call stopped() before");
 700   _kit    =    kit;
 701   _sp     =    kit->sp();
 702   _reexecute = kit->jvms()->_reexecute;
 703 }
 704 PreserveReexecuteState::~PreserveReexecuteState() {
 705   if (_kit->stopped()) return;
 706   _kit->jvms()->_reexecute = _reexecute;
 707   _kit->set_sp(_sp);
 708 }
 709 
 710 //------------------------------clone_map--------------------------------------
 711 // Implementation of PreserveJVMState
 712 //
 713 // Only clone_map(...) here. If this function is only used in the
 714 // PreserveJVMState class we may want to get rid of this extra
 715 // function eventually and do it all there.
 716 
 717 SafePointNode* GraphKit::clone_map() {
 718   if (map() == NULL)  return NULL;
 719 
 720   // Clone the memory edge first
 721   Node* mem = MergeMemNode::make(map()->memory());
 722   gvn().set_type_bottom(mem);
 723 
 724   SafePointNode *clonemap = (SafePointNode*)map()->clone();
 725   JVMState* jvms = this->jvms();
 726   JVMState* clonejvms = jvms->clone_shallow(C);
 727   clonemap->set_memory(mem);
 728   clonemap->set_jvms(clonejvms);
 729   clonejvms->set_map(clonemap);
 730   record_for_igvn(clonemap);
 731   gvn().set_type_bottom(clonemap);
 732   return clonemap;
 733 }
 734 
 735 
 736 //-----------------------------set_map_clone-----------------------------------
 737 void GraphKit::set_map_clone(SafePointNode* m) {
 738   _map = m;
 739   _map = clone_map();
 740   _map->set_next_exception(NULL);
 741   debug_only(verify_map());
 742 }
 743 
 744 
 745 //----------------------------kill_dead_locals---------------------------------
 746 // Detect any locals which are known to be dead, and force them to top.
 747 void GraphKit::kill_dead_locals() {
 748   // Consult the liveness information for the locals.  If any
 749   // of them are unused, then they can be replaced by top().  This
 750   // should help register allocation time and cut down on the size
 751   // of the deoptimization information.
 752 
 753   // This call is made from many of the bytecode handling
 754   // subroutines called from the Big Switch in do_one_bytecode.
 755   // Every bytecode which might include a slow path is responsible
 756   // for killing its dead locals.  The more consistent we
 757   // are about killing deads, the fewer useless phis will be
 758   // constructed for them at various merge points.
 759 
 760   // bci can be -1 (InvocationEntryBci).  We return the entry
 761   // liveness for the method.
 762 
 763   if (method() == NULL || method()->code_size() == 0) {
 764     // We are building a graph for a call to a native method.
 765     // All locals are live.
 766     return;
 767   }
 768 
 769   ResourceMark rm;
 770 
 771   // Consult the liveness information for the locals.  If any
 772   // of them are unused, then they can be replaced by top().  This
 773   // should help register allocation time and cut down on the size
 774   // of the deoptimization information.
 775   MethodLivenessResult live_locals = method()->liveness_at_bci(bci());
 776 
 777   int len = (int)live_locals.size();
 778   assert(len <= jvms()->loc_size(), "too many live locals");
 779   for (int local = 0; local < len; local++) {
 780     if (!live_locals.at(local)) {
 781       set_local(local, top());
 782     }
 783   }
 784 }
 785 
 786 #ifdef ASSERT
 787 //-------------------------dead_locals_are_killed------------------------------
 788 // Return true if all dead locals are set to top in the map.
 789 // Used to assert "clean" debug info at various points.
 790 bool GraphKit::dead_locals_are_killed() {
 791   if (method() == NULL || method()->code_size() == 0) {
 792     // No locals need to be dead, so all is as it should be.
 793     return true;
 794   }
 795 
 796   // Make sure somebody called kill_dead_locals upstream.
 797   ResourceMark rm;
 798   for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) {
 799     if (jvms->loc_size() == 0)  continue;  // no locals to consult
 800     SafePointNode* map = jvms->map();
 801     ciMethod* method = jvms->method();
 802     int       bci    = jvms->bci();
 803     if (jvms == this->jvms()) {
 804       bci = this->bci();  // it might not yet be synched
 805     }
 806     MethodLivenessResult live_locals = method->liveness_at_bci(bci);
 807     int len = (int)live_locals.size();
 808     if (!live_locals.is_valid() || len == 0)
 809       // This method is trivial, or is poisoned by a breakpoint.
 810       return true;
 811     assert(len == jvms->loc_size(), "live map consistent with locals map");
 812     for (int local = 0; local < len; local++) {
 813       if (!live_locals.at(local) && map->local(jvms, local) != top()) {
 814         if (PrintMiscellaneous && (Verbose || WizardMode)) {
 815           tty->print_cr("Zombie local %d: ", local);
 816           jvms->dump();
 817         }
 818         return false;
 819       }
 820     }
 821   }
 822   return true;
 823 }
 824 
 825 #endif //ASSERT
 826 
 827 // Helper function for adding JVMState and debug information to node
 828 void GraphKit::add_safepoint_edges(SafePointNode* call, bool must_throw) {
 829   // Add the safepoint edges to the call (or other safepoint).
 830 
 831   // Make sure dead locals are set to top.  This
 832   // should help register allocation time and cut down on the size
 833   // of the deoptimization information.
 834   assert(dead_locals_are_killed(), "garbage in debug info before safepoint");
 835 
 836   // Walk the inline list to fill in the correct set of JVMState's
 837   // Also fill in the associated edges for each JVMState.
 838 
 839   // If the bytecode needs to be reexecuted we need to put
 840   // the arguments back on the stack.
 841   const bool should_reexecute = jvms()->should_reexecute();
 842   JVMState* youngest_jvms = should_reexecute ? sync_jvms_for_reexecute() : sync_jvms();
 843 
 844   // NOTE: set_bci (called from sync_jvms) might reset the reexecute bit to
 845   // undefined if the bci is different.  This is normal for Parse but it
 846   // should not happen for LibraryCallKit because only one bci is processed.
 847   assert(!is_LibraryCallKit() || (jvms()->should_reexecute() == should_reexecute),
 848          "in LibraryCallKit the reexecute bit should not change");
 849 
 850   // If we are guaranteed to throw, we can prune everything but the
 851   // input to the current bytecode.
 852   bool can_prune_locals = false;
 853   uint stack_slots_not_pruned = 0;
 854   int inputs = 0, depth = 0;
 855   if (must_throw) {
 856     assert(method() == youngest_jvms->method(), "sanity");
 857     if (compute_stack_effects(inputs, depth)) {
 858       can_prune_locals = true;
 859       stack_slots_not_pruned = inputs;
 860     }
 861   }
 862 
 863   if (env()->should_retain_local_variables()) {
 864     // At any safepoint, this method can get breakpointed, which would
 865     // then require an immediate deoptimization.
 866     can_prune_locals = false;  // do not prune locals
 867     stack_slots_not_pruned = 0;
 868   }
 869 
 870   C->add_safepoint_edges(call, youngest_jvms, can_prune_locals, stack_slots_not_pruned);
 871 }
 872 
 873 bool GraphKit::compute_stack_effects(int& inputs, int& depth) {
 874   Bytecodes::Code code = java_bc();
 875   if (code == Bytecodes::_wide) {
 876     code = method()->java_code_at_bci(bci() + 1);
 877   }
 878 
 879   BasicType rtype = T_ILLEGAL;
 880   int       rsize = 0;
 881 
 882   if (code != Bytecodes::_illegal) {
 883     depth = Bytecodes::depth(code); // checkcast=0, athrow=-1
 884     rtype = Bytecodes::result_type(code); // checkcast=P, athrow=V
 885     if (rtype < T_CONFLICT)
 886       rsize = type2size[rtype];
 887   }
 888 
 889   switch (code) {
 890   case Bytecodes::_illegal:
 891     return false;
 892 
 893   case Bytecodes::_ldc:
 894   case Bytecodes::_ldc_w:
 895   case Bytecodes::_ldc2_w:
 896     inputs = 0;
 897     break;
 898 
 899   case Bytecodes::_dup:         inputs = 1;  break;
 900   case Bytecodes::_dup_x1:      inputs = 2;  break;
 901   case Bytecodes::_dup_x2:      inputs = 3;  break;
 902   case Bytecodes::_dup2:        inputs = 2;  break;
 903   case Bytecodes::_dup2_x1:     inputs = 3;  break;
 904   case Bytecodes::_dup2_x2:     inputs = 4;  break;
 905   case Bytecodes::_swap:        inputs = 2;  break;
 906   case Bytecodes::_arraylength: inputs = 1;  break;
 907 
 908   case Bytecodes::_getstatic:
 909   case Bytecodes::_putstatic:
 910   case Bytecodes::_getfield:
 911   case Bytecodes::_putfield:
 912     {
 913       bool ignored_will_link;
 914       ciField* field = method()->get_field_at_bci(bci(), ignored_will_link);
 915       int      size  = field->type()->size();
 916       bool is_get = (depth >= 0), is_static = (depth & 1);
 917       inputs = (is_static ? 0 : 1);
 918       if (is_get) {
 919         depth = size - inputs;
 920       } else {
 921         inputs += size;        // putxxx pops the value from the stack
 922         depth = - inputs;
 923       }
 924     }
 925     break;
 926 
 927   case Bytecodes::_invokevirtual:
 928   case Bytecodes::_invokespecial:
 929   case Bytecodes::_invokestatic:
 930   case Bytecodes::_invokedynamic:
 931   case Bytecodes::_invokeinterface:
 932     {
 933       bool ignored_will_link;
 934       ciSignature* declared_signature = NULL;
 935       ciMethod* ignored_callee = method()->get_method_at_bci(bci(), ignored_will_link, &declared_signature);
 936       assert(declared_signature != NULL, "cannot be null");
 937       inputs   = declared_signature->arg_size_for_bc(code);
 938       int size = declared_signature->return_type()->size();
 939       depth = size - inputs;
 940     }
 941     break;
 942 
 943   case Bytecodes::_multianewarray:
 944     {
 945       ciBytecodeStream iter(method());
 946       iter.reset_to_bci(bci());
 947       iter.next();
 948       inputs = iter.get_dimensions();
 949       assert(rsize == 1, "");
 950       depth = rsize - inputs;
 951     }
 952     break;
 953 
 954   case Bytecodes::_vwithfield: {
 955     bool ignored_will_link;
 956     ciField* field = method()->get_field_at_bci(bci(), ignored_will_link);
 957     int      size  = field->type()->size();
 958     inputs = size+1;
 959     depth = rsize - inputs;
 960     break;
 961   }
 962 
 963   case Bytecodes::_ireturn:
 964   case Bytecodes::_lreturn:
 965   case Bytecodes::_freturn:
 966   case Bytecodes::_dreturn:
 967   case Bytecodes::_areturn:
 968   case Bytecodes::_vreturn:
 969     assert(rsize == -depth, "");
 970     inputs = rsize;
 971     break;
 972 
 973   case Bytecodes::_jsr:
 974   case Bytecodes::_jsr_w:
 975     inputs = 0;
 976     depth  = 1;                  // S.B. depth=1, not zero
 977     break;
 978 
 979   default:
 980     // bytecode produces a typed result
 981     inputs = rsize - depth;
 982     assert(inputs >= 0, "");
 983     break;
 984   }
 985 
 986 #ifdef ASSERT
 987   // spot check
 988   int outputs = depth + inputs;
 989   assert(outputs >= 0, "sanity");
 990   switch (code) {
 991   case Bytecodes::_checkcast: assert(inputs == 1 && outputs == 1, ""); break;
 992   case Bytecodes::_athrow:    assert(inputs == 1 && outputs == 0, ""); break;
 993   case Bytecodes::_aload_0:   assert(inputs == 0 && outputs == 1, ""); break;
 994   case Bytecodes::_return:    assert(inputs == 0 && outputs == 0, ""); break;
 995   case Bytecodes::_drem:      assert(inputs == 4 && outputs == 2, ""); break;
 996   default:                    break;
 997   }
 998 #endif //ASSERT
 999 
1000   return true;
1001 }
1002 
1003 
1004 
1005 //------------------------------basic_plus_adr---------------------------------
1006 Node* GraphKit::basic_plus_adr(Node* base, Node* ptr, Node* offset) {
1007   // short-circuit a common case
1008   if (offset == intcon(0))  return ptr;
1009   return _gvn.transform( new AddPNode(base, ptr, offset) );
1010 }
1011 
1012 Node* GraphKit::ConvI2L(Node* offset) {
1013   // short-circuit a common case
1014   jint offset_con = find_int_con(offset, Type::OffsetBot);
1015   if (offset_con != Type::OffsetBot) {
1016     return longcon((jlong) offset_con);
1017   }
1018   return _gvn.transform( new ConvI2LNode(offset));
1019 }
1020 
1021 Node* GraphKit::ConvI2UL(Node* offset) {
1022   juint offset_con = (juint) find_int_con(offset, Type::OffsetBot);
1023   if (offset_con != (juint) Type::OffsetBot) {
1024     return longcon((julong) offset_con);
1025   }
1026   Node* conv = _gvn.transform( new ConvI2LNode(offset));
1027   Node* mask = _gvn.transform(ConLNode::make((julong) max_juint));
1028   return _gvn.transform( new AndLNode(conv, mask) );
1029 }
1030 
1031 Node* GraphKit::ConvL2I(Node* offset) {
1032   // short-circuit a common case
1033   jlong offset_con = find_long_con(offset, (jlong)Type::OffsetBot);
1034   if (offset_con != (jlong)Type::OffsetBot) {
1035     return intcon((int) offset_con);
1036   }
1037   return _gvn.transform( new ConvL2INode(offset));
1038 }
1039 
1040 //-------------------------load_object_klass-----------------------------------
1041 Node* GraphKit::load_object_klass(Node* obj) {
1042   // Special-case a fresh allocation to avoid building nodes:
1043   Node* akls = AllocateNode::Ideal_klass(obj, &_gvn);
1044   if (akls != NULL)  return akls;
1045   Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes());
1046   return _gvn.transform(LoadKlassNode::make(_gvn, NULL, immutable_memory(), k_adr, TypeInstPtr::KLASS));
1047 }
1048 
1049 //-------------------------load_array_length-----------------------------------
1050 Node* GraphKit::load_array_length(Node* array) {
1051   // Special-case a fresh allocation to avoid building nodes:
1052   AllocateArrayNode* alloc = AllocateArrayNode::Ideal_array_allocation(array, &_gvn);
1053   Node *alen;
1054   if (alloc == NULL) {
1055     Node *r_adr = basic_plus_adr(array, arrayOopDesc::length_offset_in_bytes());
1056     alen = _gvn.transform( new LoadRangeNode(0, immutable_memory(), r_adr, TypeInt::POS));
1057   } else {
1058     alen = alloc->Ideal_length();
1059     Node* ccast = alloc->make_ideal_length(_gvn.type(array)->is_oopptr(), &_gvn);
1060     if (ccast != alen) {
1061       alen = _gvn.transform(ccast);
1062     }
1063   }
1064   return alen;
1065 }
1066 
1067 //------------------------------do_null_check----------------------------------
1068 // Helper function to do a NULL pointer check.  Returned value is
1069 // the incoming address with NULL casted away.  You are allowed to use the
1070 // not-null value only if you are control dependent on the test.
1071 #ifndef PRODUCT
1072 extern int explicit_null_checks_inserted,
1073            explicit_null_checks_elided;
1074 #endif
1075 Node* GraphKit::null_check_common(Node* value, BasicType type,
1076                                   // optional arguments for variations:
1077                                   bool assert_null,
1078                                   Node* *null_control,
1079                                   bool speculative) {
1080   assert(!assert_null || null_control == NULL, "not both at once");
1081   if (stopped())  return top();
1082   NOT_PRODUCT(explicit_null_checks_inserted++);
1083 
1084   // Construct NULL check
1085   Node *chk = NULL;
1086   switch(type) {
1087     case T_LONG   : chk = new CmpLNode(value, _gvn.zerocon(T_LONG)); break;
1088     case T_INT    : chk = new CmpINode(value, _gvn.intcon(0)); break;
1089     case T_VALUETYPE : // fall through
1090     case T_ARRAY  : // fall through
1091       type = T_OBJECT;  // simplify further tests
1092     case T_OBJECT : {
1093       const Type *t = _gvn.type( value );
1094 
1095       const TypeOopPtr* tp = t->isa_oopptr();
1096       if (tp != NULL && tp->klass() != NULL && !tp->klass()->is_loaded()
1097           // Only for do_null_check, not any of its siblings:
1098           && !assert_null && null_control == NULL) {
1099         // Usually, any field access or invocation on an unloaded oop type
1100         // will simply fail to link, since the statically linked class is
1101         // likely also to be unloaded.  However, in -Xcomp mode, sometimes
1102         // the static class is loaded but the sharper oop type is not.
1103         // Rather than checking for this obscure case in lots of places,
1104         // we simply observe that a null check on an unloaded class
1105         // will always be followed by a nonsense operation, so we
1106         // can just issue the uncommon trap here.
1107         // Our access to the unloaded class will only be correct
1108         // after it has been loaded and initialized, which requires
1109         // a trip through the interpreter.
1110 #ifndef PRODUCT
1111         if (WizardMode) { tty->print("Null check of unloaded "); tp->klass()->print(); tty->cr(); }
1112 #endif
1113         uncommon_trap(Deoptimization::Reason_unloaded,
1114                       Deoptimization::Action_reinterpret,
1115                       tp->klass(), "!loaded");
1116         return top();
1117       }
1118 
1119       if (assert_null) {
1120         // See if the type is contained in NULL_PTR.
1121         // If so, then the value is already null.
1122         if (t->higher_equal(TypePtr::NULL_PTR)) {
1123           NOT_PRODUCT(explicit_null_checks_elided++);
1124           return value;           // Elided null assert quickly!
1125         }
1126       } else {
1127         // See if mixing in the NULL pointer changes type.
1128         // If so, then the NULL pointer was not allowed in the original
1129         // type.  In other words, "value" was not-null.
1130         if (t->meet(TypePtr::NULL_PTR) != t->remove_speculative()) {
1131           // same as: if (!TypePtr::NULL_PTR->higher_equal(t)) ...
1132           NOT_PRODUCT(explicit_null_checks_elided++);
1133           return value;           // Elided null check quickly!
1134         }
1135       }
1136       chk = new CmpPNode( value, null() );
1137       break;
1138     }
1139 
1140     default:
1141       fatal("unexpected type: %s", type2name(type));
1142   }
1143   assert(chk != NULL, "sanity check");
1144   chk = _gvn.transform(chk);
1145 
1146   BoolTest::mask btest = assert_null ? BoolTest::eq : BoolTest::ne;
1147   BoolNode *btst = new BoolNode( chk, btest);
1148   Node   *tst = _gvn.transform( btst );
1149 
1150   //-----------
1151   // if peephole optimizations occurred, a prior test existed.
1152   // If a prior test existed, maybe it dominates as we can avoid this test.
1153   if (tst != btst && type == T_OBJECT) {
1154     // At this point we want to scan up the CFG to see if we can
1155     // find an identical test (and so avoid this test altogether).
1156     Node *cfg = control();
1157     int depth = 0;
1158     while( depth < 16 ) {       // Limit search depth for speed
1159       if( cfg->Opcode() == Op_IfTrue &&
1160           cfg->in(0)->in(1) == tst ) {
1161         // Found prior test.  Use "cast_not_null" to construct an identical
1162         // CastPP (and hence hash to) as already exists for the prior test.
1163         // Return that casted value.
1164         if (assert_null) {
1165           replace_in_map(value, null());
1166           return null();  // do not issue the redundant test
1167         }
1168         Node *oldcontrol = control();
1169         set_control(cfg);
1170         Node *res = cast_not_null(value);
1171         set_control(oldcontrol);
1172         NOT_PRODUCT(explicit_null_checks_elided++);
1173         return res;
1174       }
1175       cfg = IfNode::up_one_dom(cfg, /*linear_only=*/ true);
1176       if (cfg == NULL)  break;  // Quit at region nodes
1177       depth++;
1178     }
1179   }
1180 
1181   //-----------
1182   // Branch to failure if null
1183   float ok_prob = PROB_MAX;  // a priori estimate:  nulls never happen
1184   Deoptimization::DeoptReason reason;
1185   if (assert_null) {
1186     reason = Deoptimization::reason_null_assert(speculative);
1187   } else if (type == T_OBJECT) {
1188     reason = Deoptimization::reason_null_check(speculative);
1189   } else {
1190     reason = Deoptimization::Reason_div0_check;
1191   }
1192   // %%% Since Reason_unhandled is not recorded on a per-bytecode basis,
1193   // ciMethodData::has_trap_at will return a conservative -1 if any
1194   // must-be-null assertion has failed.  This could cause performance
1195   // problems for a method after its first do_null_assert failure.
1196   // Consider using 'Reason_class_check' instead?
1197 
1198   // To cause an implicit null check, we set the not-null probability
1199   // to the maximum (PROB_MAX).  For an explicit check the probability
1200   // is set to a smaller value.
1201   if (null_control != NULL || too_many_traps(reason)) {
1202     // probability is less likely
1203     ok_prob =  PROB_LIKELY_MAG(3);
1204   } else if (!assert_null &&
1205              (ImplicitNullCheckThreshold > 0) &&
1206              method() != NULL &&
1207              (method()->method_data()->trap_count(reason)
1208               >= (uint)ImplicitNullCheckThreshold)) {
1209     ok_prob =  PROB_LIKELY_MAG(3);
1210   }
1211 
1212   if (null_control != NULL) {
1213     IfNode* iff = create_and_map_if(control(), tst, ok_prob, COUNT_UNKNOWN);
1214     Node* null_true = _gvn.transform( new IfFalseNode(iff));
1215     set_control(      _gvn.transform( new IfTrueNode(iff)));
1216 #ifndef PRODUCT
1217     if (null_true == top()) {
1218       explicit_null_checks_elided++;
1219     }
1220 #endif
1221     (*null_control) = null_true;
1222   } else {
1223     BuildCutout unless(this, tst, ok_prob);
1224     // Check for optimizer eliding test at parse time
1225     if (stopped()) {
1226       // Failure not possible; do not bother making uncommon trap.
1227       NOT_PRODUCT(explicit_null_checks_elided++);
1228     } else if (assert_null) {
1229       uncommon_trap(reason,
1230                     Deoptimization::Action_make_not_entrant,
1231                     NULL, "assert_null");
1232     } else {
1233       replace_in_map(value, zerocon(type));
1234       builtin_throw(reason);
1235     }
1236   }
1237 
1238   // Must throw exception, fall-thru not possible?
1239   if (stopped()) {
1240     return top();               // No result
1241   }
1242 
1243   if (assert_null) {
1244     // Cast obj to null on this path.
1245     replace_in_map(value, zerocon(type));
1246     return zerocon(type);
1247   }
1248 
1249   // Cast obj to not-null on this path, if there is no null_control.
1250   // (If there is a null_control, a non-null value may come back to haunt us.)
1251   if (type == T_OBJECT) {
1252     Node* cast = cast_not_null(value, false);
1253     if (null_control == NULL || (*null_control) == top())
1254       replace_in_map(value, cast);
1255     value = cast;
1256   }
1257 
1258   return value;
1259 }
1260 
1261 
1262 //------------------------------cast_not_null----------------------------------
1263 // Cast obj to not-null on this path
1264 Node* GraphKit::cast_not_null(Node* obj, bool do_replace_in_map) {
1265   const Type *t = _gvn.type(obj);
1266   const Type *t_not_null = t->join_speculative(TypePtr::NOTNULL);
1267   // Object is already not-null?
1268   if( t == t_not_null ) return obj;
1269 
1270   Node *cast = new CastPPNode(obj,t_not_null);
1271   cast->init_req(0, control());
1272   cast = _gvn.transform( cast );
1273 
1274   // Scan for instances of 'obj' in the current JVM mapping.
1275   // These instances are known to be not-null after the test.
1276   if (do_replace_in_map)
1277     replace_in_map(obj, cast);
1278 
1279   return cast;                  // Return casted value
1280 }
1281 
1282 // Sometimes in intrinsics, we implicitly know an object is not null
1283 // (there's no actual null check) so we can cast it to not null. In
1284 // the course of optimizations, the input to the cast can become null.
1285 // In that case that data path will die and we need the control path
1286 // to become dead as well to keep the graph consistent. So we have to
1287 // add a check for null for which one branch can't be taken. It uses
1288 // an Opaque4 node that will cause the check to be removed after loop
1289 // opts so the test goes away and the compiled code doesn't execute a
1290 // useless check.
1291 Node* GraphKit::must_be_not_null(Node* value, bool do_replace_in_map) {
1292   Node* chk = _gvn.transform(new CmpPNode(value, null()));
1293   Node *tst = _gvn.transform(new BoolNode(chk, BoolTest::ne));
1294   Node* opaq = _gvn.transform(new Opaque4Node(C, tst, intcon(1)));
1295   IfNode *iff = new IfNode(control(), opaq, PROB_MAX, COUNT_UNKNOWN);
1296   _gvn.set_type(iff, iff->Value(&_gvn));
1297   Node *if_f = _gvn.transform(new IfFalseNode(iff));
1298   Node *frame = _gvn.transform(new ParmNode(C->start(), TypeFunc::FramePtr));
1299   Node *halt = _gvn.transform(new HaltNode(if_f, frame));
1300   C->root()->add_req(halt);
1301   Node *if_t = _gvn.transform(new IfTrueNode(iff));
1302   set_control(if_t);
1303   return cast_not_null(value, do_replace_in_map);
1304 }
1305 
1306 
1307 //--------------------------replace_in_map-------------------------------------
1308 void GraphKit::replace_in_map(Node* old, Node* neww) {
1309   if (old == neww) {
1310     return;
1311   }
1312 
1313   map()->replace_edge(old, neww);
1314 
1315   // Note: This operation potentially replaces any edge
1316   // on the map.  This includes locals, stack, and monitors
1317   // of the current (innermost) JVM state.
1318 
1319   // don't let inconsistent types from profiling escape this
1320   // method
1321 
1322   const Type* told = _gvn.type(old);
1323   const Type* tnew = _gvn.type(neww);
1324 
1325   if (!tnew->higher_equal(told)) {
1326     return;
1327   }
1328 
1329   map()->record_replaced_node(old, neww);
1330 }
1331 
1332 
1333 //=============================================================================
1334 //--------------------------------memory---------------------------------------
1335 Node* GraphKit::memory(uint alias_idx) {
1336   MergeMemNode* mem = merged_memory();
1337   Node* p = mem->memory_at(alias_idx);
1338   _gvn.set_type(p, Type::MEMORY);  // must be mapped
1339   return p;
1340 }
1341 
1342 //-----------------------------reset_memory------------------------------------
1343 Node* GraphKit::reset_memory() {
1344   Node* mem = map()->memory();
1345   // do not use this node for any more parsing!
1346   debug_only( map()->set_memory((Node*)NULL) );
1347   return _gvn.transform( mem );
1348 }
1349 
1350 //------------------------------set_all_memory---------------------------------
1351 void GraphKit::set_all_memory(Node* newmem) {
1352   Node* mergemem = MergeMemNode::make(newmem);
1353   gvn().set_type_bottom(mergemem);
1354   map()->set_memory(mergemem);
1355 }
1356 
1357 //------------------------------set_all_memory_call----------------------------
1358 void GraphKit::set_all_memory_call(Node* call, bool separate_io_proj) {
1359   Node* newmem = _gvn.transform( new ProjNode(call, TypeFunc::Memory, separate_io_proj) );
1360   set_all_memory(newmem);
1361 }
1362 
1363 //=============================================================================
1364 //
1365 // parser factory methods for MemNodes
1366 //
1367 // These are layered on top of the factory methods in LoadNode and StoreNode,
1368 // and integrate with the parser's memory state and _gvn engine.
1369 //
1370 
1371 // factory methods in "int adr_idx"
1372 Node* GraphKit::make_load(Node* ctl, Node* adr, const Type* t, BasicType bt,
1373                           int adr_idx,
1374                           MemNode::MemOrd mo,
1375                           LoadNode::ControlDependency control_dependency,
1376                           bool require_atomic_access,
1377                           bool unaligned,
1378                           bool mismatched) {
1379   assert(adr_idx != Compile::AliasIdxTop, "use other make_load factory" );
1380   const TypePtr* adr_type = NULL; // debug-mode-only argument
1381   debug_only(adr_type = C->get_adr_type(adr_idx));
1382   Node* mem = memory(adr_idx);
1383   Node* ld;
1384   if (require_atomic_access && bt == T_LONG) {
1385     ld = LoadLNode::make_atomic(ctl, mem, adr, adr_type, t, mo, control_dependency, unaligned, mismatched);
1386   } else if (require_atomic_access && bt == T_DOUBLE) {
1387     ld = LoadDNode::make_atomic(ctl, mem, adr, adr_type, t, mo, control_dependency, unaligned, mismatched);
1388   } else {
1389     ld = LoadNode::make(_gvn, ctl, mem, adr, adr_type, t, bt, mo, control_dependency, unaligned, mismatched);
1390   }
1391   ld = _gvn.transform(ld);
1392   if (bt == T_VALUETYPE) {
1393     // Loading a non-flattened value type from memory requires a null check.
1394     ld = ValueTypeNode::make(this, ld, true /* null check */);
1395   } else if (((bt == T_OBJECT) && C->do_escape_analysis()) || C->eliminate_boxing()) {
1396     // Improve graph before escape analysis and boxing elimination.
1397     record_for_igvn(ld);
1398   }
1399   return ld;
1400 }
1401 
1402 Node* GraphKit::store_to_memory(Node* ctl, Node* adr, Node *val, BasicType bt,
1403                                 int adr_idx,
1404                                 MemNode::MemOrd mo,
1405                                 bool require_atomic_access,
1406                                 bool unaligned,
1407                                 bool mismatched) {
1408   assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
1409   const TypePtr* adr_type = NULL;
1410   debug_only(adr_type = C->get_adr_type(adr_idx));
1411   Node *mem = memory(adr_idx);
1412   Node* st;
1413   if (require_atomic_access && bt == T_LONG) {
1414     st = StoreLNode::make_atomic(ctl, mem, adr, adr_type, val, mo);
1415   } else if (require_atomic_access && bt == T_DOUBLE) {
1416     st = StoreDNode::make_atomic(ctl, mem, adr, adr_type, val, mo);
1417   } else {
1418     st = StoreNode::make(_gvn, ctl, mem, adr, adr_type, val, bt, mo);
1419   }
1420   if (unaligned) {
1421     st->as_Store()->set_unaligned_access();
1422   }
1423   if (mismatched) {
1424     st->as_Store()->set_mismatched_access();
1425   }
1426   st = _gvn.transform(st);
1427   set_memory(st, adr_idx);
1428   // Back-to-back stores can only remove intermediate store with DU info
1429   // so push on worklist for optimizer.
1430   if (mem->req() > MemNode::Address && adr == mem->in(MemNode::Address))
1431     record_for_igvn(st);
1432 
1433   return st;
1434 }
1435 
1436 
1437 void GraphKit::pre_barrier(bool do_load,
1438                            Node* ctl,
1439                            Node* obj,
1440                            Node* adr,
1441                            uint  adr_idx,
1442                            Node* val,
1443                            const TypeOopPtr* val_type,
1444                            Node* pre_val,
1445                            BasicType bt) {
1446 
1447   BarrierSet* bs = Universe::heap()->barrier_set();
1448   set_control(ctl);
1449   switch (bs->kind()) {
1450     case BarrierSet::G1SATBCTLogging:
1451       g1_write_barrier_pre(do_load, obj, adr, adr_idx, val, val_type, pre_val, bt);
1452       break;
1453 
1454     case BarrierSet::CardTableForRS:
1455     case BarrierSet::CardTableExtension:
1456     case BarrierSet::ModRef:
1457       break;
1458 
1459     default      :
1460       ShouldNotReachHere();
1461 
1462   }
1463 }
1464 
1465 bool GraphKit::can_move_pre_barrier() const {
1466   BarrierSet* bs = Universe::heap()->barrier_set();
1467   switch (bs->kind()) {
1468     case BarrierSet::G1SATBCTLogging:
1469       return true; // Can move it if no safepoint
1470 
1471     case BarrierSet::CardTableForRS:
1472     case BarrierSet::CardTableExtension:
1473     case BarrierSet::ModRef:
1474       return true; // There is no pre-barrier
1475 
1476     default      :
1477       ShouldNotReachHere();
1478   }
1479   return false;
1480 }
1481 
1482 void GraphKit::post_barrier(Node* ctl,
1483                             Node* store,
1484                             Node* obj,
1485                             Node* adr,
1486                             uint  adr_idx,
1487                             Node* val,
1488                             BasicType bt,
1489                             bool use_precise) {
1490   BarrierSet* bs = Universe::heap()->barrier_set();
1491   set_control(ctl);
1492   switch (bs->kind()) {
1493     case BarrierSet::G1SATBCTLogging:
1494       g1_write_barrier_post(store, obj, adr, adr_idx, val, bt, use_precise);
1495       break;
1496 
1497     case BarrierSet::CardTableForRS:
1498     case BarrierSet::CardTableExtension:
1499       write_barrier_post(store, obj, adr, adr_idx, val, use_precise);
1500       break;
1501 
1502     case BarrierSet::ModRef:
1503       break;
1504 
1505     default      :
1506       ShouldNotReachHere();
1507 
1508   }
1509 }
1510 
1511 Node* GraphKit::store_oop(Node* ctl,
1512                           Node* obj,
1513                           Node* adr,
1514                           const TypePtr* adr_type,
1515                           Node* val,
1516                           const TypeOopPtr* val_type,
1517                           BasicType bt,
1518                           bool use_precise,
1519                           MemNode::MemOrd mo,
1520                           bool mismatched) {
1521   // Transformation of a value which could be NULL pointer (CastPP #NULL)
1522   // could be delayed during Parse (for example, in adjust_map_after_if()).
1523   // Execute transformation here to avoid barrier generation in such case.
1524   if (_gvn.type(val) == TypePtr::NULL_PTR)
1525     val = _gvn.makecon(TypePtr::NULL_PTR);
1526 
1527   set_control(ctl);
1528   if (stopped()) return top(); // Dead path ?
1529 
1530   assert(bt == T_OBJECT || bt == T_VALUETYPE, "sanity");
1531   assert(val != NULL, "not dead path");
1532   uint adr_idx = C->get_alias_index(adr_type);
1533   assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
1534 
1535   if (val->is_ValueType()) {
1536     // Allocate value type and get oop
1537     val = val->as_ValueType()->allocate(this)->get_oop();
1538   }
1539 
1540   pre_barrier(true /* do_load */,
1541               control(), obj, adr, adr_idx, val, val_type,
1542               NULL /* pre_val */,
1543               bt);
1544 
1545   Node* store = store_to_memory(control(), adr, val, bt, adr_idx, mo, mismatched);
1546   post_barrier(control(), store, obj, adr, adr_idx, val, bt, use_precise);
1547   return store;
1548 }
1549 
1550 // Could be an array or object we don't know at compile time (unsafe ref.)
1551 Node* GraphKit::store_oop_to_unknown(Node* ctl,
1552                              Node* obj,   // containing obj
1553                              Node* adr,  // actual adress to store val at
1554                              const TypePtr* adr_type,
1555                              Node* val,
1556                              BasicType bt,
1557                              MemNode::MemOrd mo,
1558                              bool mismatched) {
1559   Compile::AliasType* at = C->alias_type(adr_type);
1560   const TypeOopPtr* val_type = NULL;
1561   if (adr_type->isa_instptr()) {
1562     if (at->field() != NULL) {
1563       // known field.  This code is a copy of the do_put_xxx logic.
1564       ciField* field = at->field();
1565       if (!field->type()->is_loaded()) {
1566         val_type = TypeInstPtr::BOTTOM;
1567       } else {
1568         val_type = TypeOopPtr::make_from_klass(field->type()->as_klass());
1569       }
1570     }
1571   } else if (adr_type->isa_aryptr()) {
1572     val_type = adr_type->is_aryptr()->elem()->make_oopptr();
1573   }
1574   if (val_type == NULL) {
1575     val_type = TypeInstPtr::BOTTOM;
1576   }
1577   return store_oop(ctl, obj, adr, adr_type, val, val_type, bt, true, mo, mismatched);
1578 }
1579 
1580 
1581 //-------------------------array_element_address-------------------------
1582 Node* GraphKit::array_element_address(Node* ary, Node* idx, BasicType elembt,
1583                                       const TypeInt* sizetype, Node* ctrl) {
1584   uint shift  = exact_log2(type2aelembytes(elembt));
1585   ciKlass* arytype_klass = _gvn.type(ary)->is_aryptr()->klass();
1586   if (arytype_klass->is_value_array_klass()) {
1587     ciValueArrayKlass* vak = arytype_klass->as_value_array_klass();
1588     shift = vak->log2_element_size();
1589   }
1590   uint header = arrayOopDesc::base_offset_in_bytes(elembt);
1591 
1592   // short-circuit a common case (saves lots of confusing waste motion)
1593   jint idx_con = find_int_con(idx, -1);
1594   if (idx_con >= 0) {
1595     intptr_t offset = header + ((intptr_t)idx_con << shift);
1596     return basic_plus_adr(ary, offset);
1597   }
1598 
1599   // must be correct type for alignment purposes
1600   Node* base  = basic_plus_adr(ary, header);
1601   idx = Compile::conv_I2X_index(&_gvn, idx, sizetype, ctrl);
1602   Node* scale = _gvn.transform( new LShiftXNode(idx, intcon(shift)) );
1603   return basic_plus_adr(ary, base, scale);
1604 }
1605 
1606 //-------------------------load_array_element-------------------------
1607 Node* GraphKit::load_array_element(Node* ctl, Node* ary, Node* idx, const TypeAryPtr* arytype) {
1608   const Type* elemtype = arytype->elem();
1609   BasicType elembt = elemtype->array_element_basic_type();
1610   assert(elembt != T_VALUETYPE, "value types are not supported by this method");
1611   Node* adr = array_element_address(ary, idx, elembt, arytype->size());
1612   if (elembt == T_NARROWOOP) {
1613     elembt = T_OBJECT; // To satisfy switch in LoadNode::make()
1614   }
1615   Node* ld = make_load(ctl, adr, elemtype, elembt, arytype, MemNode::unordered);
1616   return ld;
1617 }
1618 
1619 //-------------------------set_arguments_for_java_call-------------------------
1620 // Arguments (pre-popped from the stack) are taken from the JVMS.
1621 void GraphKit::set_arguments_for_java_call(CallJavaNode* call) {
1622   // Add the call arguments:
1623   const TypeTuple* domain = call->tf()->domain_sig();
1624   uint nargs = domain->cnt();
1625   for (uint i = TypeFunc::Parms, idx = TypeFunc::Parms; i < nargs; i++) {
1626     Node* arg = argument(i-TypeFunc::Parms);
1627     if (ValueTypePassFieldsAsArgs) {
1628       if (arg->is_ValueType()) {
1629         ValueTypeNode* vt = arg->as_ValueType();
1630         if (!domain->field_at(i)->is_valuetypeptr()->is__Value()) {
1631           // We don't pass value type arguments by reference but instead
1632           // pass each field of the value type
1633           idx += vt->pass_fields(call, idx, *this);
1634           // If a value type argument is passed as fields, attach the Method* to the call site
1635           // to be able to access the extended signature later via attached_method_before_pc().
1636           // For example, see CompiledMethod::preserve_callee_argument_oops().
1637           call->set_override_symbolic_info(true);
1638         } else {
1639           arg = arg->as_ValueType()->allocate(this)->get_oop();
1640           call->init_req(idx, arg);
1641           idx++;
1642         }
1643       } else {
1644         call->init_req(idx, arg);
1645         idx++;
1646       }
1647     } else {
1648       if (arg->is_ValueType()) {
1649         // Pass value type argument via oop to callee
1650         arg = arg->as_ValueType()->allocate(this)->get_oop();
1651       }
1652       call->init_req(i, arg);
1653     }
1654   }
1655 }
1656 
1657 //---------------------------set_edges_for_java_call---------------------------
1658 // Connect a newly created call into the current JVMS.
1659 // A return value node (if any) is returned from set_edges_for_java_call.
1660 void GraphKit::set_edges_for_java_call(CallJavaNode* call, bool must_throw, bool separate_io_proj) {
1661 
1662   // Add the predefined inputs:
1663   call->init_req( TypeFunc::Control, control() );
1664   call->init_req( TypeFunc::I_O    , i_o() );
1665   call->init_req( TypeFunc::Memory , reset_memory() );
1666   call->init_req( TypeFunc::FramePtr, frameptr() );
1667   call->init_req( TypeFunc::ReturnAdr, top() );
1668 
1669   add_safepoint_edges(call, must_throw);
1670 
1671   Node* xcall = _gvn.transform(call);
1672 
1673   if (xcall == top()) {
1674     set_control(top());
1675     return;
1676   }
1677   assert(xcall == call, "call identity is stable");
1678 
1679   // Re-use the current map to produce the result.
1680 
1681   set_control(_gvn.transform(new ProjNode(call, TypeFunc::Control)));
1682   set_i_o(    _gvn.transform(new ProjNode(call, TypeFunc::I_O    , separate_io_proj)));
1683   set_all_memory_call(xcall, separate_io_proj);
1684 
1685   //return xcall;   // no need, caller already has it
1686 }
1687 
1688 Node* GraphKit::set_results_for_java_call(CallJavaNode* call, bool separate_io_proj) {
1689   if (stopped())  return top();  // maybe the call folded up?
1690 
1691   // Note:  Since any out-of-line call can produce an exception,
1692   // we always insert an I_O projection from the call into the result.
1693 
1694   make_slow_call_ex(call, env()->Throwable_klass(), separate_io_proj);
1695 
1696   if (separate_io_proj) {
1697     // The caller requested separate projections be used by the fall
1698     // through and exceptional paths, so replace the projections for
1699     // the fall through path.
1700     set_i_o(_gvn.transform( new ProjNode(call, TypeFunc::I_O) ));
1701     set_all_memory(_gvn.transform( new ProjNode(call, TypeFunc::Memory) ));
1702   }
1703 
1704   // Capture the return value, if any.
1705   Node* ret;
1706   if (call->method() == NULL ||
1707       call->method()->return_type()->basic_type() == T_VOID) {
1708     ret = top();
1709   } else {
1710     if (!call->tf()->returns_value_type_as_fields()) {
1711       ret = _gvn.transform(new ProjNode(call, TypeFunc::Parms));
1712     } else {
1713       // Return of multiple values (value type fields): we create a
1714       // ValueType node, each field is a projection from the call.
1715       const TypeTuple* range_sig = call->tf()->range_sig();
1716       const Type* t = range_sig->field_at(TypeFunc::Parms);
1717       assert(t->isa_valuetypeptr(), "only value types for multiple return values");
1718       ciValueKlass* vk = t->is_valuetypeptr()->value_type()->value_klass();
1719       Node* ctl = control();
1720       ret = ValueTypeNode::make(_gvn, ctl, merged_memory(), call, vk, TypeFunc::Parms+1, false);
1721       set_control(ctl);
1722     }
1723   }
1724 
1725   return ret;
1726 }
1727 
1728 //--------------------set_predefined_input_for_runtime_call--------------------
1729 // Reading and setting the memory state is way conservative here.
1730 // The real problem is that I am not doing real Type analysis on memory,
1731 // so I cannot distinguish card mark stores from other stores.  Across a GC
1732 // point the Store Barrier and the card mark memory has to agree.  I cannot
1733 // have a card mark store and its barrier split across the GC point from
1734 // either above or below.  Here I get that to happen by reading ALL of memory.
1735 // A better answer would be to separate out card marks from other memory.
1736 // For now, return the input memory state, so that it can be reused
1737 // after the call, if this call has restricted memory effects.
1738 Node* GraphKit::set_predefined_input_for_runtime_call(SafePointNode* call) {
1739   // Set fixed predefined input arguments
1740   Node* memory = reset_memory();
1741   call->init_req( TypeFunc::Control,   control()  );
1742   call->init_req( TypeFunc::I_O,       top()      ); // does no i/o
1743   call->init_req( TypeFunc::Memory,    memory     ); // may gc ptrs
1744   call->init_req( TypeFunc::FramePtr,  frameptr() );
1745   call->init_req( TypeFunc::ReturnAdr, top()      );
1746   return memory;
1747 }
1748 
1749 //-------------------set_predefined_output_for_runtime_call--------------------
1750 // Set control and memory (not i_o) from the call.
1751 // If keep_mem is not NULL, use it for the output state,
1752 // except for the RawPtr output of the call, if hook_mem is TypeRawPtr::BOTTOM.
1753 // If hook_mem is NULL, this call produces no memory effects at all.
1754 // If hook_mem is a Java-visible memory slice (such as arraycopy operands),
1755 // then only that memory slice is taken from the call.
1756 // In the last case, we must put an appropriate memory barrier before
1757 // the call, so as to create the correct anti-dependencies on loads
1758 // preceding the call.
1759 void GraphKit::set_predefined_output_for_runtime_call(Node* call,
1760                                                       Node* keep_mem,
1761                                                       const TypePtr* hook_mem) {
1762   // no i/o
1763   set_control(_gvn.transform( new ProjNode(call,TypeFunc::Control) ));
1764   if (keep_mem) {
1765     // First clone the existing memory state
1766     set_all_memory(keep_mem);
1767     if (hook_mem != NULL) {
1768       // Make memory for the call
1769       Node* mem = _gvn.transform( new ProjNode(call, TypeFunc::Memory) );
1770       // Set the RawPtr memory state only.  This covers all the heap top/GC stuff
1771       // We also use hook_mem to extract specific effects from arraycopy stubs.
1772       set_memory(mem, hook_mem);
1773     }
1774     // ...else the call has NO memory effects.
1775 
1776     // Make sure the call advertises its memory effects precisely.
1777     // This lets us build accurate anti-dependences in gcm.cpp.
1778     assert(C->alias_type(call->adr_type()) == C->alias_type(hook_mem),
1779            "call node must be constructed correctly");
1780   } else {
1781     assert(hook_mem == NULL, "");
1782     // This is not a "slow path" call; all memory comes from the call.
1783     set_all_memory_call(call);
1784   }
1785 }
1786 
1787 
1788 // Replace the call with the current state of the kit.
1789 void GraphKit::replace_call(CallNode* call, Node* result, bool do_replaced_nodes) {
1790   JVMState* ejvms = NULL;
1791   if (has_exceptions()) {
1792     ejvms = transfer_exceptions_into_jvms();
1793   }
1794 
1795   ReplacedNodes replaced_nodes = map()->replaced_nodes();
1796   ReplacedNodes replaced_nodes_exception;
1797   Node* ex_ctl = top();
1798 
1799   SafePointNode* final_state = stop();
1800 
1801   // Find all the needed outputs of this call
1802   CallProjections callprojs;
1803   call->extract_projections(&callprojs, true);
1804 
1805   Node* init_mem = call->in(TypeFunc::Memory);
1806   Node* final_mem = final_state->in(TypeFunc::Memory);
1807   Node* final_ctl = final_state->in(TypeFunc::Control);
1808   Node* final_io = final_state->in(TypeFunc::I_O);
1809 
1810   // Replace all the old call edges with the edges from the inlining result
1811   if (callprojs.fallthrough_catchproj != NULL) {
1812     C->gvn_replace_by(callprojs.fallthrough_catchproj, final_ctl);
1813   }
1814   if (callprojs.fallthrough_memproj != NULL) {
1815     if (final_mem->is_MergeMem()) {
1816       // Parser's exits MergeMem was not transformed but may be optimized
1817       final_mem = _gvn.transform(final_mem);
1818     }
1819     C->gvn_replace_by(callprojs.fallthrough_memproj,   final_mem);
1820   }
1821   if (callprojs.fallthrough_ioproj != NULL) {
1822     C->gvn_replace_by(callprojs.fallthrough_ioproj,    final_io);
1823   }
1824 
1825   // Replace the result with the new result if it exists and is used
1826   if (callprojs.resproj != NULL && result != NULL) {
1827     C->gvn_replace_by(callprojs.resproj, result);
1828   }
1829 
1830   if (ejvms == NULL) {
1831     // No exception edges to simply kill off those paths
1832     if (callprojs.catchall_catchproj != NULL) {
1833       C->gvn_replace_by(callprojs.catchall_catchproj, C->top());
1834     }
1835     if (callprojs.catchall_memproj != NULL) {
1836       C->gvn_replace_by(callprojs.catchall_memproj,   C->top());
1837     }
1838     if (callprojs.catchall_ioproj != NULL) {
1839       C->gvn_replace_by(callprojs.catchall_ioproj,    C->top());
1840     }
1841     // Replace the old exception object with top
1842     if (callprojs.exobj != NULL) {
1843       C->gvn_replace_by(callprojs.exobj, C->top());
1844     }
1845   } else {
1846     GraphKit ekit(ejvms);
1847 
1848     // Load my combined exception state into the kit, with all phis transformed:
1849     SafePointNode* ex_map = ekit.combine_and_pop_all_exception_states();
1850     replaced_nodes_exception = ex_map->replaced_nodes();
1851 
1852     Node* ex_oop = ekit.use_exception_state(ex_map);
1853 
1854     if (callprojs.catchall_catchproj != NULL) {
1855       C->gvn_replace_by(callprojs.catchall_catchproj, ekit.control());
1856       ex_ctl = ekit.control();
1857     }
1858     if (callprojs.catchall_memproj != NULL) {
1859       C->gvn_replace_by(callprojs.catchall_memproj,   ekit.reset_memory());
1860     }
1861     if (callprojs.catchall_ioproj != NULL) {
1862       C->gvn_replace_by(callprojs.catchall_ioproj,    ekit.i_o());
1863     }
1864 
1865     // Replace the old exception object with the newly created one
1866     if (callprojs.exobj != NULL) {
1867       C->gvn_replace_by(callprojs.exobj, ex_oop);
1868     }
1869   }
1870 
1871   // Disconnect the call from the graph
1872   call->disconnect_inputs(NULL, C);
1873   C->gvn_replace_by(call, C->top());
1874 
1875   // Clean up any MergeMems that feed other MergeMems since the
1876   // optimizer doesn't like that.
1877   if (final_mem->is_MergeMem()) {
1878     Node_List wl;
1879     for (SimpleDUIterator i(final_mem); i.has_next(); i.next()) {
1880       Node* m = i.get();
1881       if (m->is_MergeMem() && !wl.contains(m)) {
1882         wl.push(m);
1883       }
1884     }
1885     while (wl.size()  > 0) {
1886       _gvn.transform(wl.pop());
1887     }
1888   }
1889 
1890   if (callprojs.fallthrough_catchproj != NULL && !final_ctl->is_top() && do_replaced_nodes) {
1891     replaced_nodes.apply(C, final_ctl);
1892   }
1893   if (!ex_ctl->is_top() && do_replaced_nodes) {
1894     replaced_nodes_exception.apply(C, ex_ctl);
1895   }
1896 }
1897 
1898 
1899 //------------------------------increment_counter------------------------------
1900 // for statistics: increment a VM counter by 1
1901 
1902 void GraphKit::increment_counter(address counter_addr) {
1903   Node* adr1 = makecon(TypeRawPtr::make(counter_addr));
1904   increment_counter(adr1);
1905 }
1906 
1907 void GraphKit::increment_counter(Node* counter_addr) {
1908   int adr_type = Compile::AliasIdxRaw;
1909   Node* ctrl = control();
1910   Node* cnt  = make_load(ctrl, counter_addr, TypeInt::INT, T_INT, adr_type, MemNode::unordered);
1911   Node* incr = _gvn.transform(new AddINode(cnt, _gvn.intcon(1)));
1912   store_to_memory(ctrl, counter_addr, incr, T_INT, adr_type, MemNode::unordered);
1913 }
1914 
1915 
1916 //------------------------------uncommon_trap----------------------------------
1917 // Bail out to the interpreter in mid-method.  Implemented by calling the
1918 // uncommon_trap blob.  This helper function inserts a runtime call with the
1919 // right debug info.
1920 void GraphKit::uncommon_trap(int trap_request,
1921                              ciKlass* klass, const char* comment,
1922                              bool must_throw,
1923                              bool keep_exact_action) {
1924   if (failing())  stop();
1925   if (stopped())  return; // trap reachable?
1926 
1927   // Note:  If ProfileTraps is true, and if a deopt. actually
1928   // occurs here, the runtime will make sure an MDO exists.  There is
1929   // no need to call method()->ensure_method_data() at this point.
1930 
1931   // Set the stack pointer to the right value for reexecution:
1932   set_sp(reexecute_sp());
1933 
1934 #ifdef ASSERT
1935   if (!must_throw) {
1936     // Make sure the stack has at least enough depth to execute
1937     // the current bytecode.
1938     int inputs, ignored_depth;
1939     if (compute_stack_effects(inputs, ignored_depth)) {
1940       assert(sp() >= inputs, "must have enough JVMS stack to execute %s: sp=%d, inputs=%d",
1941              Bytecodes::name(java_bc()), sp(), inputs);
1942     }
1943   }
1944 #endif
1945 
1946   Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(trap_request);
1947   Deoptimization::DeoptAction action = Deoptimization::trap_request_action(trap_request);
1948 
1949   switch (action) {
1950   case Deoptimization::Action_maybe_recompile:
1951   case Deoptimization::Action_reinterpret:
1952     // Temporary fix for 6529811 to allow virtual calls to be sure they
1953     // get the chance to go from mono->bi->mega
1954     if (!keep_exact_action &&
1955         Deoptimization::trap_request_index(trap_request) < 0 &&
1956         too_many_recompiles(reason)) {
1957       // This BCI is causing too many recompilations.
1958       if (C->log() != NULL) {
1959         C->log()->elem("observe that='trap_action_change' reason='%s' from='%s' to='none'",
1960                 Deoptimization::trap_reason_name(reason),
1961                 Deoptimization::trap_action_name(action));
1962       }
1963       action = Deoptimization::Action_none;
1964       trap_request = Deoptimization::make_trap_request(reason, action);
1965     } else {
1966       C->set_trap_can_recompile(true);
1967     }
1968     break;
1969   case Deoptimization::Action_make_not_entrant:
1970     C->set_trap_can_recompile(true);
1971     break;
1972   case Deoptimization::Action_none:
1973   case Deoptimization::Action_make_not_compilable:
1974     break;
1975   default:
1976 #ifdef ASSERT
1977     fatal("unknown action %d: %s", action, Deoptimization::trap_action_name(action));
1978 #endif
1979     break;
1980   }
1981 
1982   if (TraceOptoParse) {
1983     char buf[100];
1984     tty->print_cr("Uncommon trap %s at bci:%d",
1985                   Deoptimization::format_trap_request(buf, sizeof(buf),
1986                                                       trap_request), bci());
1987   }
1988 
1989   CompileLog* log = C->log();
1990   if (log != NULL) {
1991     int kid = (klass == NULL)? -1: log->identify(klass);
1992     log->begin_elem("uncommon_trap bci='%d'", bci());
1993     char buf[100];
1994     log->print(" %s", Deoptimization::format_trap_request(buf, sizeof(buf),
1995                                                           trap_request));
1996     if (kid >= 0)         log->print(" klass='%d'", kid);
1997     if (comment != NULL)  log->print(" comment='%s'", comment);
1998     log->end_elem();
1999   }
2000 
2001   // Make sure any guarding test views this path as very unlikely
2002   Node *i0 = control()->in(0);
2003   if (i0 != NULL && i0->is_If()) {        // Found a guarding if test?
2004     IfNode *iff = i0->as_If();
2005     float f = iff->_prob;   // Get prob
2006     if (control()->Opcode() == Op_IfTrue) {
2007       if (f > PROB_UNLIKELY_MAG(4))
2008         iff->_prob = PROB_MIN;
2009     } else {
2010       if (f < PROB_LIKELY_MAG(4))
2011         iff->_prob = PROB_MAX;
2012     }
2013   }
2014 
2015   // Clear out dead values from the debug info.
2016   kill_dead_locals();
2017 
2018   // Now insert the uncommon trap subroutine call
2019   address call_addr = SharedRuntime::uncommon_trap_blob()->entry_point();
2020   const TypePtr* no_memory_effects = NULL;
2021   // Pass the index of the class to be loaded
2022   Node* call = make_runtime_call(RC_NO_LEAF | RC_UNCOMMON |
2023                                  (must_throw ? RC_MUST_THROW : 0),
2024                                  OptoRuntime::uncommon_trap_Type(),
2025                                  call_addr, "uncommon_trap", no_memory_effects,
2026                                  intcon(trap_request));
2027   assert(call->as_CallStaticJava()->uncommon_trap_request() == trap_request,
2028          "must extract request correctly from the graph");
2029   assert(trap_request != 0, "zero value reserved by uncommon_trap_request");
2030 
2031   call->set_req(TypeFunc::ReturnAdr, returnadr());
2032   // The debug info is the only real input to this call.
2033 
2034   // Halt-and-catch fire here.  The above call should never return!
2035   HaltNode* halt = new HaltNode(control(), frameptr());
2036   _gvn.set_type_bottom(halt);
2037   root()->add_req(halt);
2038 
2039   stop_and_kill_map();
2040 }
2041 
2042 
2043 //--------------------------just_allocated_object------------------------------
2044 // Report the object that was just allocated.
2045 // It must be the case that there are no intervening safepoints.
2046 // We use this to determine if an object is so "fresh" that
2047 // it does not require card marks.
2048 Node* GraphKit::just_allocated_object(Node* current_control) {
2049   if (C->recent_alloc_ctl() == current_control)
2050     return C->recent_alloc_obj();
2051   return NULL;
2052 }
2053 
2054 
2055 void GraphKit::round_double_arguments(ciMethod* dest_method) {
2056   // (Note:  TypeFunc::make has a cache that makes this fast.)
2057   const TypeFunc* tf    = TypeFunc::make(dest_method);
2058   int             nargs = tf->domain_sig()->cnt() - TypeFunc::Parms;
2059   for (int j = 0; j < nargs; j++) {
2060     const Type *targ = tf->domain_sig()->field_at(j + TypeFunc::Parms);
2061     if( targ->basic_type() == T_DOUBLE ) {
2062       // If any parameters are doubles, they must be rounded before
2063       // the call, dstore_rounding does gvn.transform
2064       Node *arg = argument(j);
2065       arg = dstore_rounding(arg);
2066       set_argument(j, arg);
2067     }
2068   }
2069 }
2070 
2071 /**
2072  * Record profiling data exact_kls for Node n with the type system so
2073  * that it can propagate it (speculation)
2074  *
2075  * @param n          node that the type applies to
2076  * @param exact_kls  type from profiling
2077  * @param maybe_null did profiling see null?
2078  *
2079  * @return           node with improved type
2080  */
2081 Node* GraphKit::record_profile_for_speculation(Node* n, ciKlass* exact_kls, ProfilePtrKind ptr_kind) {
2082   const Type* current_type = _gvn.type(n);
2083   assert(UseTypeSpeculation, "type speculation must be on");
2084 
2085   const TypePtr* speculative = current_type->speculative();
2086 
2087   // Should the klass from the profile be recorded in the speculative type?
2088   if (current_type->would_improve_type(exact_kls, jvms()->depth())) {
2089     const TypeKlassPtr* tklass = TypeKlassPtr::make(exact_kls);
2090     const TypeOopPtr* xtype = tklass->as_instance_type();
2091     assert(xtype->klass_is_exact(), "Should be exact");
2092     // Any reason to believe n is not null (from this profiling or a previous one)?
2093     assert(ptr_kind != ProfileAlwaysNull, "impossible here");
2094     const TypePtr* ptr = (ptr_kind == ProfileMaybeNull && current_type->speculative_maybe_null()) ? TypePtr::BOTTOM : TypePtr::NOTNULL;
2095     // record the new speculative type's depth
2096     speculative = xtype->cast_to_ptr_type(ptr->ptr())->is_ptr();
2097     speculative = speculative->with_inline_depth(jvms()->depth());
2098   } else if (current_type->would_improve_ptr(ptr_kind)) {
2099     // Profiling report that null was never seen so we can change the
2100     // speculative type to non null ptr.
2101     if (ptr_kind == ProfileAlwaysNull) {
2102       speculative = TypePtr::NULL_PTR;
2103     } else {
2104       assert(ptr_kind == ProfileNeverNull, "nothing else is an improvement");
2105       const TypePtr* ptr = TypePtr::NOTNULL;
2106       if (speculative != NULL) {
2107         speculative = speculative->cast_to_ptr_type(ptr->ptr())->is_ptr();
2108       } else {
2109         speculative = ptr;
2110       }
2111     }
2112   }
2113 
2114   if (speculative != current_type->speculative()) {
2115     // Build a type with a speculative type (what we think we know
2116     // about the type but will need a guard when we use it)
2117     const TypeOopPtr* spec_type = TypeOopPtr::make(TypePtr::BotPTR, Type::Offset::bottom, TypeOopPtr::InstanceBot, speculative);
2118     // We're changing the type, we need a new CheckCast node to carry
2119     // the new type. The new type depends on the control: what
2120     // profiling tells us is only valid from here as far as we can
2121     // tell.
2122     Node* cast = new CheckCastPPNode(control(), n, current_type->remove_speculative()->join_speculative(spec_type));
2123     cast = _gvn.transform(cast);
2124     replace_in_map(n, cast);
2125     n = cast;
2126   }
2127 
2128   return n;
2129 }
2130 
2131 /**
2132  * Record profiling data from receiver profiling at an invoke with the
2133  * type system so that it can propagate it (speculation)
2134  *
2135  * @param n  receiver node
2136  *
2137  * @return   node with improved type
2138  */
2139 Node* GraphKit::record_profiled_receiver_for_speculation(Node* n) {
2140   if (!UseTypeSpeculation) {
2141     return n;
2142   }
2143   ciKlass* exact_kls = profile_has_unique_klass();
2144   ProfilePtrKind ptr_kind = ProfileMaybeNull;
2145   if ((java_bc() == Bytecodes::_checkcast ||
2146        java_bc() == Bytecodes::_instanceof ||
2147        java_bc() == Bytecodes::_aastore) &&
2148       method()->method_data()->is_mature()) {
2149     ciProfileData* data = method()->method_data()->bci_to_data(bci());
2150     if (data != NULL) {
2151       if (!data->as_BitData()->null_seen()) {
2152         ptr_kind = ProfileNeverNull;
2153       } else {
2154         assert(data->is_ReceiverTypeData(), "bad profile data type");
2155         ciReceiverTypeData* call = (ciReceiverTypeData*)data->as_ReceiverTypeData();
2156         uint i = 0;
2157         for (; i < call->row_limit(); i++) {
2158           ciKlass* receiver = call->receiver(i);
2159           if (receiver != NULL) {
2160             break;
2161           }
2162         }
2163         ptr_kind = (i == call->row_limit()) ? ProfileAlwaysNull : ProfileMaybeNull;
2164       }
2165     }
2166   }
2167   return record_profile_for_speculation(n, exact_kls, ptr_kind);
2168 }
2169 
2170 /**
2171  * Record profiling data from argument profiling at an invoke with the
2172  * type system so that it can propagate it (speculation)
2173  *
2174  * @param dest_method  target method for the call
2175  * @param bc           what invoke bytecode is this?
2176  */
2177 void GraphKit::record_profiled_arguments_for_speculation(ciMethod* dest_method, Bytecodes::Code bc) {
2178   if (!UseTypeSpeculation) {
2179     return;
2180   }
2181   const TypeFunc* tf    = TypeFunc::make(dest_method);
2182   int             nargs = tf->domain_sig()->cnt() - TypeFunc::Parms;
2183   int skip = Bytecodes::has_receiver(bc) ? 1 : 0;
2184   for (int j = skip, i = 0; j < nargs && i < TypeProfileArgsLimit; j++) {
2185     const Type *targ = tf->domain_sig()->field_at(j + TypeFunc::Parms);
2186     if (targ->isa_oopptr() && !targ->isa_valuetypeptr()) {
2187       ProfilePtrKind ptr_kind = ProfileMaybeNull;
2188       ciKlass* better_type = NULL;
2189       if (method()->argument_profiled_type(bci(), i, better_type, ptr_kind)) {
2190         record_profile_for_speculation(argument(j), better_type, ptr_kind);
2191       }
2192       i++;
2193     }
2194   }
2195 }
2196 
2197 /**
2198  * Record profiling data from parameter profiling at an invoke with
2199  * the type system so that it can propagate it (speculation)
2200  */
2201 void GraphKit::record_profiled_parameters_for_speculation() {
2202   if (!UseTypeSpeculation) {
2203     return;
2204   }
2205   for (int i = 0, j = 0; i < method()->arg_size() ; i++) {
2206     if (_gvn.type(local(i))->isa_oopptr()) {
2207       ProfilePtrKind ptr_kind = ProfileMaybeNull;
2208       ciKlass* better_type = NULL;
2209       if (method()->parameter_profiled_type(j, better_type, ptr_kind)) {
2210         record_profile_for_speculation(local(i), better_type, ptr_kind);
2211       }
2212       j++;
2213     }
2214   }
2215 }
2216 
2217 /**
2218  * Record profiling data from return value profiling at an invoke with
2219  * the type system so that it can propagate it (speculation)
2220  */
2221 void GraphKit::record_profiled_return_for_speculation() {
2222   if (!UseTypeSpeculation) {
2223     return;
2224   }
2225   ProfilePtrKind ptr_kind = ProfileMaybeNull;
2226   ciKlass* better_type = NULL;
2227   if (method()->return_profiled_type(bci(), better_type, ptr_kind)) {
2228     // If profiling reports a single type for the return value,
2229     // feed it to the type system so it can propagate it as a
2230     // speculative type
2231     record_profile_for_speculation(stack(sp()-1), better_type, ptr_kind);
2232   }
2233 }
2234 
2235 void GraphKit::round_double_result(ciMethod* dest_method) {
2236   // A non-strict method may return a double value which has an extended
2237   // exponent, but this must not be visible in a caller which is 'strict'
2238   // If a strict caller invokes a non-strict callee, round a double result
2239 
2240   BasicType result_type = dest_method->return_type()->basic_type();
2241   assert( method() != NULL, "must have caller context");
2242   if( result_type == T_DOUBLE && method()->is_strict() && !dest_method->is_strict() ) {
2243     // Destination method's return value is on top of stack
2244     // dstore_rounding() does gvn.transform
2245     Node *result = pop_pair();
2246     result = dstore_rounding(result);
2247     push_pair(result);
2248   }
2249 }
2250 
2251 // rounding for strict float precision conformance
2252 Node* GraphKit::precision_rounding(Node* n) {
2253   return UseStrictFP && _method->flags().is_strict()
2254     && UseSSE == 0 && Matcher::strict_fp_requires_explicit_rounding
2255     ? _gvn.transform( new RoundFloatNode(0, n) )
2256     : n;
2257 }
2258 
2259 // rounding for strict double precision conformance
2260 Node* GraphKit::dprecision_rounding(Node *n) {
2261   return UseStrictFP && _method->flags().is_strict()
2262     && UseSSE <= 1 && Matcher::strict_fp_requires_explicit_rounding
2263     ? _gvn.transform( new RoundDoubleNode(0, n) )
2264     : n;
2265 }
2266 
2267 // rounding for non-strict double stores
2268 Node* GraphKit::dstore_rounding(Node* n) {
2269   return Matcher::strict_fp_requires_explicit_rounding
2270     && UseSSE <= 1
2271     ? _gvn.transform( new RoundDoubleNode(0, n) )
2272     : n;
2273 }
2274 
2275 //=============================================================================
2276 // Generate a fast path/slow path idiom.  Graph looks like:
2277 // [foo] indicates that 'foo' is a parameter
2278 //
2279 //              [in]     NULL
2280 //                 \    /
2281 //                  CmpP
2282 //                  Bool ne
2283 //                   If
2284 //                  /  \
2285 //              True    False-<2>
2286 //              / |
2287 //             /  cast_not_null
2288 //           Load  |    |   ^
2289 //        [fast_test]   |   |
2290 // gvn to   opt_test    |   |
2291 //          /    \      |  <1>
2292 //      True     False  |
2293 //        |         \\  |
2294 //   [slow_call]     \[fast_result]
2295 //    Ctl   Val       \      \
2296 //     |               \      \
2297 //    Catch       <1>   \      \
2298 //   /    \        ^     \      \
2299 //  Ex    No_Ex    |      \      \
2300 //  |       \   \  |       \ <2>  \
2301 //  ...      \  [slow_res] |  |    \   [null_result]
2302 //            \         \--+--+---  |  |
2303 //             \           | /    \ | /
2304 //              --------Region     Phi
2305 //
2306 //=============================================================================
2307 // Code is structured as a series of driver functions all called 'do_XXX' that
2308 // call a set of helper functions.  Helper functions first, then drivers.
2309 
2310 //------------------------------null_check_oop---------------------------------
2311 // Null check oop.  Set null-path control into Region in slot 3.
2312 // Make a cast-not-nullness use the other not-null control.  Return cast.
2313 Node* GraphKit::null_check_oop(Node* value, Node* *null_control,
2314                                bool never_see_null,
2315                                bool safe_for_replace,
2316                                bool speculative) {
2317   // Initial NULL check taken path
2318   (*null_control) = top();
2319   Node* cast = null_check_common(value, T_OBJECT, false, null_control, speculative);
2320 
2321   // Generate uncommon_trap:
2322   if (never_see_null && (*null_control) != top()) {
2323     // If we see an unexpected null at a check-cast we record it and force a
2324     // recompile; the offending check-cast will be compiled to handle NULLs.
2325     // If we see more than one offending BCI, then all checkcasts in the
2326     // method will be compiled to handle NULLs.
2327     PreserveJVMState pjvms(this);
2328     set_control(*null_control);
2329     replace_in_map(value, null());
2330     Deoptimization::DeoptReason reason = Deoptimization::reason_null_check(speculative);
2331     uncommon_trap(reason,
2332                   Deoptimization::Action_make_not_entrant);
2333     (*null_control) = top();    // NULL path is dead
2334   }
2335   if ((*null_control) == top() && safe_for_replace) {
2336     replace_in_map(value, cast);
2337   }
2338 
2339   // Cast away null-ness on the result
2340   return cast;
2341 }
2342 
2343 //------------------------------opt_iff----------------------------------------
2344 // Optimize the fast-check IfNode.  Set the fast-path region slot 2.
2345 // Return slow-path control.
2346 Node* GraphKit::opt_iff(Node* region, Node* iff) {
2347   IfNode *opt_iff = _gvn.transform(iff)->as_If();
2348 
2349   // Fast path taken; set region slot 2
2350   Node *fast_taken = _gvn.transform( new IfFalseNode(opt_iff) );
2351   region->init_req(2,fast_taken); // Capture fast-control
2352 
2353   // Fast path not-taken, i.e. slow path
2354   Node *slow_taken = _gvn.transform( new IfTrueNode(opt_iff) );
2355   return slow_taken;
2356 }
2357 
2358 //-----------------------------make_runtime_call-------------------------------
2359 Node* GraphKit::make_runtime_call(int flags,
2360                                   const TypeFunc* call_type, address call_addr,
2361                                   const char* call_name,
2362                                   const TypePtr* adr_type,
2363                                   // The following parms are all optional.
2364                                   // The first NULL ends the list.
2365                                   Node* parm0, Node* parm1,
2366                                   Node* parm2, Node* parm3,
2367                                   Node* parm4, Node* parm5,
2368                                   Node* parm6, Node* parm7) {
2369   // Slow-path call
2370   bool is_leaf = !(flags & RC_NO_LEAF);
2371   bool has_io  = (!is_leaf && !(flags & RC_NO_IO));
2372   if (call_name == NULL) {
2373     assert(!is_leaf, "must supply name for leaf");
2374     call_name = OptoRuntime::stub_name(call_addr);
2375   }
2376   CallNode* call;
2377   if (!is_leaf) {
2378     call = new CallStaticJavaNode(call_type, call_addr, call_name,
2379                                            bci(), adr_type);
2380   } else if (flags & RC_NO_FP) {
2381     call = new CallLeafNoFPNode(call_type, call_addr, call_name, adr_type);
2382   } else {
2383     call = new CallLeafNode(call_type, call_addr, call_name, adr_type);
2384   }
2385 
2386   // The following is similar to set_edges_for_java_call,
2387   // except that the memory effects of the call are restricted to AliasIdxRaw.
2388 
2389   // Slow path call has no side-effects, uses few values
2390   bool wide_in  = !(flags & RC_NARROW_MEM);
2391   bool wide_out = (C->get_alias_index(adr_type) == Compile::AliasIdxBot);
2392 
2393   Node* prev_mem = NULL;
2394   if (wide_in) {
2395     prev_mem = set_predefined_input_for_runtime_call(call);
2396   } else {
2397     assert(!wide_out, "narrow in => narrow out");
2398     Node* narrow_mem = memory(adr_type);
2399     prev_mem = reset_memory();
2400     map()->set_memory(narrow_mem);
2401     set_predefined_input_for_runtime_call(call);
2402   }
2403 
2404   // Hook each parm in order.  Stop looking at the first NULL.
2405   if (parm0 != NULL) { call->init_req(TypeFunc::Parms+0, parm0);
2406   if (parm1 != NULL) { call->init_req(TypeFunc::Parms+1, parm1);
2407   if (parm2 != NULL) { call->init_req(TypeFunc::Parms+2, parm2);
2408   if (parm3 != NULL) { call->init_req(TypeFunc::Parms+3, parm3);
2409   if (parm4 != NULL) { call->init_req(TypeFunc::Parms+4, parm4);
2410   if (parm5 != NULL) { call->init_req(TypeFunc::Parms+5, parm5);
2411   if (parm6 != NULL) { call->init_req(TypeFunc::Parms+6, parm6);
2412   if (parm7 != NULL) { call->init_req(TypeFunc::Parms+7, parm7);
2413     /* close each nested if ===> */  } } } } } } } }
2414   assert(call->in(call->req()-1) != NULL, "must initialize all parms");
2415 
2416   if (!is_leaf) {
2417     // Non-leaves can block and take safepoints:
2418     add_safepoint_edges(call, ((flags & RC_MUST_THROW) != 0));
2419   }
2420   // Non-leaves can throw exceptions:
2421   if (has_io) {
2422     call->set_req(TypeFunc::I_O, i_o());
2423   }
2424 
2425   if (flags & RC_UNCOMMON) {
2426     // Set the count to a tiny probability.  Cf. Estimate_Block_Frequency.
2427     // (An "if" probability corresponds roughly to an unconditional count.
2428     // Sort of.)
2429     call->set_cnt(PROB_UNLIKELY_MAG(4));
2430   }
2431 
2432   Node* c = _gvn.transform(call);
2433   assert(c == call, "cannot disappear");
2434 
2435   if (wide_out) {
2436     // Slow path call has full side-effects.
2437     set_predefined_output_for_runtime_call(call);
2438   } else {
2439     // Slow path call has few side-effects, and/or sets few values.
2440     set_predefined_output_for_runtime_call(call, prev_mem, adr_type);
2441   }
2442 
2443   if (has_io) {
2444     set_i_o(_gvn.transform(new ProjNode(call, TypeFunc::I_O)));
2445   }
2446   return call;
2447 
2448 }
2449 
2450 //------------------------------merge_memory-----------------------------------
2451 // Merge memory from one path into the current memory state.
2452 void GraphKit::merge_memory(Node* new_mem, Node* region, int new_path) {
2453   for (MergeMemStream mms(merged_memory(), new_mem->as_MergeMem()); mms.next_non_empty2(); ) {
2454     Node* old_slice = mms.force_memory();
2455     Node* new_slice = mms.memory2();
2456     if (old_slice != new_slice) {
2457       PhiNode* phi;
2458       if (old_slice->is_Phi() && old_slice->as_Phi()->region() == region) {
2459         if (mms.is_empty()) {
2460           // clone base memory Phi's inputs for this memory slice
2461           assert(old_slice == mms.base_memory(), "sanity");
2462           phi = PhiNode::make(region, NULL, Type::MEMORY, mms.adr_type(C));
2463           _gvn.set_type(phi, Type::MEMORY);
2464           for (uint i = 1; i < phi->req(); i++) {
2465             phi->init_req(i, old_slice->in(i));
2466           }
2467         } else {
2468           phi = old_slice->as_Phi(); // Phi was generated already
2469         }
2470       } else {
2471         phi = PhiNode::make(region, old_slice, Type::MEMORY, mms.adr_type(C));
2472         _gvn.set_type(phi, Type::MEMORY);
2473       }
2474       phi->set_req(new_path, new_slice);
2475       mms.set_memory(phi);
2476     }
2477   }
2478 }
2479 
2480 //------------------------------make_slow_call_ex------------------------------
2481 // Make the exception handler hookups for the slow call
2482 void GraphKit::make_slow_call_ex(Node* call, ciInstanceKlass* ex_klass, bool separate_io_proj, bool deoptimize) {
2483   if (stopped())  return;
2484 
2485   // Make a catch node with just two handlers:  fall-through and catch-all
2486   Node* i_o  = _gvn.transform( new ProjNode(call, TypeFunc::I_O, separate_io_proj) );
2487   Node* catc = _gvn.transform( new CatchNode(control(), i_o, 2) );
2488   Node* norm = _gvn.transform( new CatchProjNode(catc, CatchProjNode::fall_through_index, CatchProjNode::no_handler_bci) );
2489   Node* excp = _gvn.transform( new CatchProjNode(catc, CatchProjNode::catch_all_index,    CatchProjNode::no_handler_bci) );
2490 
2491   { PreserveJVMState pjvms(this);
2492     set_control(excp);
2493     set_i_o(i_o);
2494 
2495     if (excp != top()) {
2496       if (deoptimize) {
2497         // Deoptimize if an exception is caught. Don't construct exception state in this case.
2498         uncommon_trap(Deoptimization::Reason_unhandled,
2499                       Deoptimization::Action_none);
2500       } else {
2501         // Create an exception state also.
2502         // Use an exact type if the caller has specified a specific exception.
2503         const Type* ex_type = TypeOopPtr::make_from_klass_unique(ex_klass)->cast_to_ptr_type(TypePtr::NotNull);
2504         Node*       ex_oop  = new CreateExNode(ex_type, control(), i_o);
2505         add_exception_state(make_exception_state(_gvn.transform(ex_oop)));
2506       }
2507     }
2508   }
2509 
2510   // Get the no-exception control from the CatchNode.
2511   set_control(norm);
2512 }
2513 
2514 static IfNode* gen_subtype_check_compare(Node* ctrl, Node* in1, Node* in2, BoolTest::mask test, float p, PhaseGVN* gvn, BasicType bt) {
2515   Node* cmp = NULL;
2516   switch(bt) {
2517   case T_INT: cmp = new CmpINode(in1, in2); break;
2518   case T_ADDRESS: cmp = new CmpPNode(in1, in2); break;
2519   default: fatal("unexpected comparison type %s", type2name(bt));
2520   }
2521   gvn->transform(cmp);
2522   Node* bol = gvn->transform(new BoolNode(cmp, test));
2523   IfNode* iff = new IfNode(ctrl, bol, p, COUNT_UNKNOWN);
2524   gvn->transform(iff);
2525   if (!bol->is_Con()) gvn->record_for_igvn(iff);
2526   return iff;
2527 }
2528 
2529 
2530 //-------------------------------gen_subtype_check-----------------------------
2531 // Generate a subtyping check.  Takes as input the subtype and supertype.
2532 // Returns 2 values: sets the default control() to the true path and returns
2533 // the false path.  Only reads invariant memory; sets no (visible) memory.
2534 // The PartialSubtypeCheckNode sets the hidden 1-word cache in the encoding
2535 // but that's not exposed to the optimizer.  This call also doesn't take in an
2536 // Object; if you wish to check an Object you need to load the Object's class
2537 // prior to coming here.
2538 Node* Phase::gen_subtype_check(Node* subklass, Node* superklass, Node** ctrl, MergeMemNode* mem, PhaseGVN* gvn) {
2539   Compile* C = gvn->C;
2540 
2541   if ((*ctrl)->is_top()) {
2542     return C->top();
2543   }
2544 
2545   // Fast check for identical types, perhaps identical constants.
2546   // The types can even be identical non-constants, in cases
2547   // involving Array.newInstance, Object.clone, etc.
2548   if (subklass == superklass)
2549     return C->top();             // false path is dead; no test needed.
2550 
2551   if (gvn->type(superklass)->singleton()) {
2552     ciKlass* superk = gvn->type(superklass)->is_klassptr()->klass();
2553     ciKlass* subk   = gvn->type(subklass)->is_klassptr()->klass();
2554 
2555     // In the common case of an exact superklass, try to fold up the
2556     // test before generating code.  You may ask, why not just generate
2557     // the code and then let it fold up?  The answer is that the generated
2558     // code will necessarily include null checks, which do not always
2559     // completely fold away.  If they are also needless, then they turn
2560     // into a performance loss.  Example:
2561     //    Foo[] fa = blah(); Foo x = fa[0]; fa[1] = x;
2562     // Here, the type of 'fa' is often exact, so the store check
2563     // of fa[1]=x will fold up, without testing the nullness of x.
2564     switch (C->static_subtype_check(superk, subk)) {
2565     case Compile::SSC_always_false:
2566       {
2567         Node* always_fail = *ctrl;
2568         *ctrl = gvn->C->top();
2569         return always_fail;
2570       }
2571     case Compile::SSC_always_true:
2572       return C->top();
2573     case Compile::SSC_easy_test:
2574       {
2575         // Just do a direct pointer compare and be done.
2576         IfNode* iff = gen_subtype_check_compare(*ctrl, subklass, superklass, BoolTest::eq, PROB_STATIC_FREQUENT, gvn, T_ADDRESS);
2577         *ctrl = gvn->transform(new IfTrueNode(iff));
2578         return gvn->transform(new IfFalseNode(iff));
2579       }
2580     case Compile::SSC_full_test:
2581       break;
2582     default:
2583       ShouldNotReachHere();
2584     }
2585   }
2586 
2587   // %%% Possible further optimization:  Even if the superklass is not exact,
2588   // if the subklass is the unique subtype of the superklass, the check
2589   // will always succeed.  We could leave a dependency behind to ensure this.
2590 
2591   // First load the super-klass's check-offset
2592   Node *p1 = gvn->transform(new AddPNode(superklass, superklass, gvn->MakeConX(in_bytes(Klass::super_check_offset_offset()))));
2593   Node* m = mem->memory_at(C->get_alias_index(gvn->type(p1)->is_ptr()));
2594   Node *chk_off = gvn->transform(new LoadINode(NULL, m, p1, gvn->type(p1)->is_ptr(), TypeInt::INT, MemNode::unordered));
2595   int cacheoff_con = in_bytes(Klass::secondary_super_cache_offset());
2596   bool might_be_cache = (gvn->find_int_con(chk_off, cacheoff_con) == cacheoff_con);
2597 
2598   // Load from the sub-klass's super-class display list, or a 1-word cache of
2599   // the secondary superclass list, or a failing value with a sentinel offset
2600   // if the super-klass is an interface or exceptionally deep in the Java
2601   // hierarchy and we have to scan the secondary superclass list the hard way.
2602   // Worst-case type is a little odd: NULL is allowed as a result (usually
2603   // klass loads can never produce a NULL).
2604   Node *chk_off_X = chk_off;
2605 #ifdef _LP64
2606   chk_off_X = gvn->transform(new ConvI2LNode(chk_off_X));
2607 #endif
2608   Node *p2 = gvn->transform(new AddPNode(subklass,subklass,chk_off_X));
2609   // For some types like interfaces the following loadKlass is from a 1-word
2610   // cache which is mutable so can't use immutable memory.  Other
2611   // types load from the super-class display table which is immutable.
2612   m = mem->memory_at(C->get_alias_index(gvn->type(p2)->is_ptr()));
2613   Node *kmem = might_be_cache ? m : C->immutable_memory();
2614   Node *nkls = gvn->transform(LoadKlassNode::make(*gvn, NULL, kmem, p2, gvn->type(p2)->is_ptr(), TypeKlassPtr::BOTTOM));
2615 
2616   // Compile speed common case: ARE a subtype and we canNOT fail
2617   if( superklass == nkls )
2618     return C->top();             // false path is dead; no test needed.
2619 
2620   // See if we get an immediate positive hit.  Happens roughly 83% of the
2621   // time.  Test to see if the value loaded just previously from the subklass
2622   // is exactly the superklass.
2623   IfNode *iff1 = gen_subtype_check_compare(*ctrl, superklass, nkls, BoolTest::eq, PROB_LIKELY(0.83f), gvn, T_ADDRESS);
2624   Node *iftrue1 = gvn->transform( new IfTrueNode (iff1));
2625   *ctrl = gvn->transform(new IfFalseNode(iff1));
2626 
2627   // Compile speed common case: Check for being deterministic right now.  If
2628   // chk_off is a constant and not equal to cacheoff then we are NOT a
2629   // subklass.  In this case we need exactly the 1 test above and we can
2630   // return those results immediately.
2631   if (!might_be_cache) {
2632     Node* not_subtype_ctrl = *ctrl;
2633     *ctrl = iftrue1; // We need exactly the 1 test above
2634     return not_subtype_ctrl;
2635   }
2636 
2637   // Gather the various success & failures here
2638   RegionNode *r_ok_subtype = new RegionNode(4);
2639   gvn->record_for_igvn(r_ok_subtype);
2640   RegionNode *r_not_subtype = new RegionNode(3);
2641   gvn->record_for_igvn(r_not_subtype);
2642 
2643   r_ok_subtype->init_req(1, iftrue1);
2644 
2645   // Check for immediate negative hit.  Happens roughly 11% of the time (which
2646   // is roughly 63% of the remaining cases).  Test to see if the loaded
2647   // check-offset points into the subklass display list or the 1-element
2648   // cache.  If it points to the display (and NOT the cache) and the display
2649   // missed then it's not a subtype.
2650   Node *cacheoff = gvn->intcon(cacheoff_con);
2651   IfNode *iff2 = gen_subtype_check_compare(*ctrl, chk_off, cacheoff, BoolTest::ne, PROB_LIKELY(0.63f), gvn, T_INT);
2652   r_not_subtype->init_req(1, gvn->transform(new IfTrueNode (iff2)));
2653   *ctrl = gvn->transform(new IfFalseNode(iff2));
2654 
2655   // Check for self.  Very rare to get here, but it is taken 1/3 the time.
2656   // No performance impact (too rare) but allows sharing of secondary arrays
2657   // which has some footprint reduction.
2658   IfNode *iff3 = gen_subtype_check_compare(*ctrl, subklass, superklass, BoolTest::eq, PROB_LIKELY(0.36f), gvn, T_ADDRESS);
2659   r_ok_subtype->init_req(2, gvn->transform(new IfTrueNode(iff3)));
2660   *ctrl = gvn->transform(new IfFalseNode(iff3));
2661 
2662   // -- Roads not taken here: --
2663   // We could also have chosen to perform the self-check at the beginning
2664   // of this code sequence, as the assembler does.  This would not pay off
2665   // the same way, since the optimizer, unlike the assembler, can perform
2666   // static type analysis to fold away many successful self-checks.
2667   // Non-foldable self checks work better here in second position, because
2668   // the initial primary superclass check subsumes a self-check for most
2669   // types.  An exception would be a secondary type like array-of-interface,
2670   // which does not appear in its own primary supertype display.
2671   // Finally, we could have chosen to move the self-check into the
2672   // PartialSubtypeCheckNode, and from there out-of-line in a platform
2673   // dependent manner.  But it is worthwhile to have the check here,
2674   // where it can be perhaps be optimized.  The cost in code space is
2675   // small (register compare, branch).
2676 
2677   // Now do a linear scan of the secondary super-klass array.  Again, no real
2678   // performance impact (too rare) but it's gotta be done.
2679   // Since the code is rarely used, there is no penalty for moving it
2680   // out of line, and it can only improve I-cache density.
2681   // The decision to inline or out-of-line this final check is platform
2682   // dependent, and is found in the AD file definition of PartialSubtypeCheck.
2683   Node* psc = gvn->transform(
2684     new PartialSubtypeCheckNode(*ctrl, subklass, superklass));
2685 
2686   IfNode *iff4 = gen_subtype_check_compare(*ctrl, psc, gvn->zerocon(T_OBJECT), BoolTest::ne, PROB_FAIR, gvn, T_ADDRESS);
2687   r_not_subtype->init_req(2, gvn->transform(new IfTrueNode (iff4)));
2688   r_ok_subtype ->init_req(3, gvn->transform(new IfFalseNode(iff4)));
2689 
2690   // Return false path; set default control to true path.
2691   *ctrl = gvn->transform(r_ok_subtype);
2692   return gvn->transform(r_not_subtype);
2693 }
2694 
2695 // Profile-driven exact type check:
2696 Node* GraphKit::type_check_receiver(Node* receiver, ciKlass* klass,
2697                                     float prob,
2698                                     Node* *casted_receiver) {
2699   const TypeKlassPtr* tklass = TypeKlassPtr::make(klass);
2700   Node* recv_klass = load_object_klass(receiver);
2701   Node* fail = type_check(recv_klass, tklass, prob);
2702   const TypeOopPtr* recv_xtype = tklass->as_instance_type();
2703   assert(recv_xtype->klass_is_exact(), "");
2704 
2705   // Subsume downstream occurrences of receiver with a cast to
2706   // recv_xtype, since now we know what the type will be.
2707   Node* cast = new CheckCastPPNode(control(), receiver, recv_xtype);
2708   (*casted_receiver) = _gvn.transform(cast);
2709   // (User must make the replace_in_map call.)
2710 
2711   return fail;
2712 }
2713 
2714 Node* GraphKit::type_check(Node* recv_klass, const TypeKlassPtr* tklass,
2715                            float prob) {
2716   //const TypeKlassPtr* tklass = TypeKlassPtr::make(klass);
2717   Node* want_klass = makecon(tklass);
2718   Node* cmp = _gvn.transform( new CmpPNode(recv_klass, want_klass));
2719   Node* bol = _gvn.transform( new BoolNode(cmp, BoolTest::eq) );
2720   IfNode* iff = create_and_xform_if(control(), bol, prob, COUNT_UNKNOWN);
2721   set_control(  _gvn.transform( new IfTrueNode (iff)));
2722   Node* fail = _gvn.transform( new IfFalseNode(iff));
2723   return fail;
2724 }
2725 
2726 
2727 //------------------------------seems_never_null-------------------------------
2728 // Use null_seen information if it is available from the profile.
2729 // If we see an unexpected null at a type check we record it and force a
2730 // recompile; the offending check will be recompiled to handle NULLs.
2731 // If we see several offending BCIs, then all checks in the
2732 // method will be recompiled.
2733 bool GraphKit::seems_never_null(Node* obj, ciProfileData* data, bool& speculating) {
2734   speculating = !_gvn.type(obj)->speculative_maybe_null();
2735   Deoptimization::DeoptReason reason = Deoptimization::reason_null_check(speculating);
2736   if (UncommonNullCast               // Cutout for this technique
2737       && obj != null()               // And not the -Xcomp stupid case?
2738       && !too_many_traps(reason)
2739       ) {
2740     if (speculating) {
2741       return true;
2742     }
2743     if (data == NULL)
2744       // Edge case:  no mature data.  Be optimistic here.
2745       return true;
2746     // If the profile has not seen a null, assume it won't happen.
2747     assert(java_bc() == Bytecodes::_checkcast ||
2748            java_bc() == Bytecodes::_instanceof ||
2749            java_bc() == Bytecodes::_aastore, "MDO must collect null_seen bit here");
2750     return !data->as_BitData()->null_seen();
2751   }
2752   speculating = false;
2753   return false;
2754 }
2755 
2756 //------------------------maybe_cast_profiled_receiver-------------------------
2757 // If the profile has seen exactly one type, narrow to exactly that type.
2758 // Subsequent type checks will always fold up.
2759 Node* GraphKit::maybe_cast_profiled_receiver(Node* not_null_obj,
2760                                              ciKlass* require_klass,
2761                                              ciKlass* spec_klass,
2762                                              bool safe_for_replace) {
2763   if (!UseTypeProfile || !TypeProfileCasts) return NULL;
2764 
2765   Deoptimization::DeoptReason reason = Deoptimization::reason_class_check(spec_klass != NULL);
2766 
2767   // Make sure we haven't already deoptimized from this tactic.
2768   if (too_many_traps(reason) || too_many_recompiles(reason))
2769     return NULL;
2770 
2771   // (No, this isn't a call, but it's enough like a virtual call
2772   // to use the same ciMethod accessor to get the profile info...)
2773   // If we have a speculative type use it instead of profiling (which
2774   // may not help us)
2775   ciKlass* exact_kls = spec_klass == NULL ? profile_has_unique_klass() : spec_klass;
2776   if (exact_kls != NULL) {// no cast failures here
2777     if (require_klass == NULL ||
2778         C->static_subtype_check(require_klass, exact_kls) == Compile::SSC_always_true) {
2779       // If we narrow the type to match what the type profile sees or
2780       // the speculative type, we can then remove the rest of the
2781       // cast.
2782       // This is a win, even if the exact_kls is very specific,
2783       // because downstream operations, such as method calls,
2784       // will often benefit from the sharper type.
2785       Node* exact_obj = not_null_obj; // will get updated in place...
2786       Node* slow_ctl  = type_check_receiver(exact_obj, exact_kls, 1.0,
2787                                             &exact_obj);
2788       { PreserveJVMState pjvms(this);
2789         set_control(slow_ctl);
2790         uncommon_trap_exact(reason, Deoptimization::Action_maybe_recompile);
2791       }
2792       if (safe_for_replace) {
2793         replace_in_map(not_null_obj, exact_obj);
2794       }
2795       return exact_obj;
2796     }
2797     // assert(ssc == Compile::SSC_always_true)... except maybe the profile lied to us.
2798   }
2799 
2800   return NULL;
2801 }
2802 
2803 /**
2804  * Cast obj to type and emit guard unless we had too many traps here
2805  * already
2806  *
2807  * @param obj       node being casted
2808  * @param type      type to cast the node to
2809  * @param not_null  true if we know node cannot be null
2810  */
2811 Node* GraphKit::maybe_cast_profiled_obj(Node* obj,
2812                                         ciKlass* type,
2813                                         bool not_null) {
2814   if (stopped()) {
2815     return obj;
2816   }
2817 
2818   // type == NULL if profiling tells us this object is always null
2819   if (type != NULL) {
2820     Deoptimization::DeoptReason class_reason = Deoptimization::Reason_speculate_class_check;
2821     Deoptimization::DeoptReason null_reason = Deoptimization::Reason_speculate_null_check;
2822 
2823     if (!too_many_traps(null_reason) && !too_many_recompiles(null_reason) &&
2824         !too_many_traps(class_reason) &&
2825         !too_many_recompiles(class_reason)) {
2826       Node* not_null_obj = NULL;
2827       // not_null is true if we know the object is not null and
2828       // there's no need for a null check
2829       if (!not_null) {
2830         Node* null_ctl = top();
2831         not_null_obj = null_check_oop(obj, &null_ctl, true, true, true);
2832         assert(null_ctl->is_top(), "no null control here");
2833       } else {
2834         not_null_obj = obj;
2835       }
2836 
2837       Node* exact_obj = not_null_obj;
2838       ciKlass* exact_kls = type;
2839       Node* slow_ctl  = type_check_receiver(exact_obj, exact_kls, 1.0,
2840                                             &exact_obj);
2841       {
2842         PreserveJVMState pjvms(this);
2843         set_control(slow_ctl);
2844         uncommon_trap_exact(class_reason, Deoptimization::Action_maybe_recompile);
2845       }
2846       replace_in_map(not_null_obj, exact_obj);
2847       obj = exact_obj;
2848     }
2849   } else {
2850     if (!too_many_traps(Deoptimization::Reason_null_assert) &&
2851         !too_many_recompiles(Deoptimization::Reason_null_assert)) {
2852       Node* exact_obj = null_assert(obj);
2853       replace_in_map(obj, exact_obj);
2854       obj = exact_obj;
2855     }
2856   }
2857   return obj;
2858 }
2859 
2860 //-------------------------------gen_instanceof--------------------------------
2861 // Generate an instance-of idiom.  Used by both the instance-of bytecode
2862 // and the reflective instance-of call.
2863 Node* GraphKit::gen_instanceof(Node* obj, Node* superklass, bool safe_for_replace) {
2864   kill_dead_locals();           // Benefit all the uncommon traps
2865   assert( !stopped(), "dead parse path should be checked in callers" );
2866   assert(!TypePtr::NULL_PTR->higher_equal(_gvn.type(superklass)->is_klassptr()),
2867          "must check for not-null not-dead klass in callers");
2868 
2869   // Make the merge point
2870   enum { _obj_path = 1, _fail_path, _null_path, PATH_LIMIT };
2871   RegionNode* region = new RegionNode(PATH_LIMIT);
2872   Node*       phi    = new PhiNode(region, TypeInt::BOOL);
2873   C->set_has_split_ifs(true); // Has chance for split-if optimization
2874 
2875   ciProfileData* data = NULL;
2876   if (java_bc() == Bytecodes::_instanceof) {  // Only for the bytecode
2877     data = method()->method_data()->bci_to_data(bci());
2878   }
2879   bool speculative_not_null = false;
2880   bool never_see_null = (ProfileDynamicTypes  // aggressive use of profile
2881                          && seems_never_null(obj, data, speculative_not_null));
2882 
2883   // Null check; get casted pointer; set region slot 3
2884   Node* null_ctl = top();
2885   Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null, safe_for_replace, speculative_not_null);
2886 
2887   // If not_null_obj is dead, only null-path is taken
2888   if (stopped()) {              // Doing instance-of on a NULL?
2889     set_control(null_ctl);
2890     return intcon(0);
2891   }
2892   region->init_req(_null_path, null_ctl);
2893   phi   ->init_req(_null_path, intcon(0)); // Set null path value
2894   if (null_ctl == top()) {
2895     // Do this eagerly, so that pattern matches like is_diamond_phi
2896     // will work even during parsing.
2897     assert(_null_path == PATH_LIMIT-1, "delete last");
2898     region->del_req(_null_path);
2899     phi   ->del_req(_null_path);
2900   }
2901 
2902   // Do we know the type check always succeed?
2903   bool known_statically = false;
2904   if (_gvn.type(superklass)->singleton()) {
2905     ciKlass* superk = _gvn.type(superklass)->is_klassptr()->klass();
2906     ciKlass* subk = _gvn.type(obj)->is_oopptr()->klass();
2907     if (subk != NULL && subk->is_loaded()) {
2908       int static_res = C->static_subtype_check(superk, subk);
2909       known_statically = (static_res == Compile::SSC_always_true || static_res == Compile::SSC_always_false);
2910     }
2911   }
2912 
2913   if (!known_statically) {
2914     const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
2915     // We may not have profiling here or it may not help us. If we
2916     // have a speculative type use it to perform an exact cast.
2917     ciKlass* spec_obj_type = obj_type->speculative_type();
2918     if (spec_obj_type != NULL || (ProfileDynamicTypes && data != NULL)) {
2919       Node* cast_obj = maybe_cast_profiled_receiver(not_null_obj, NULL, spec_obj_type, safe_for_replace);
2920       if (stopped()) {            // Profile disagrees with this path.
2921         set_control(null_ctl);    // Null is the only remaining possibility.
2922         return intcon(0);
2923       }
2924       if (cast_obj != NULL) {
2925         not_null_obj = cast_obj;
2926       }
2927     }
2928   }
2929 
2930   // Load the object's klass
2931   Node* obj_klass = load_object_klass(not_null_obj);
2932 
2933   // Generate the subtype check
2934   Node* not_subtype_ctrl = gen_subtype_check(obj_klass, superklass);
2935 
2936   // Plug in the success path to the general merge in slot 1.
2937   region->init_req(_obj_path, control());
2938   phi   ->init_req(_obj_path, intcon(1));
2939 
2940   // Plug in the failing path to the general merge in slot 2.
2941   region->init_req(_fail_path, not_subtype_ctrl);
2942   phi   ->init_req(_fail_path, intcon(0));
2943 
2944   // Return final merged results
2945   set_control( _gvn.transform(region) );
2946   record_for_igvn(region);
2947 
2948   // If we know the type check always succeeds then we don't use the
2949   // profiling data at this bytecode. Don't lose it, feed it to the
2950   // type system as a speculative type.
2951   if (safe_for_replace) {
2952     Node* casted_obj = record_profiled_receiver_for_speculation(obj);
2953     replace_in_map(obj, casted_obj);
2954   }
2955 
2956   return _gvn.transform(phi);
2957 }
2958 
2959 //-------------------------------gen_checkcast---------------------------------
2960 // Generate a checkcast idiom.  Used by both the checkcast bytecode and the
2961 // array store bytecode.  Stack must be as-if BEFORE doing the bytecode so the
2962 // uncommon-trap paths work.  Adjust stack after this call.
2963 // If failure_control is supplied and not null, it is filled in with
2964 // the control edge for the cast failure.  Otherwise, an appropriate
2965 // uncommon trap or exception is thrown.
2966 Node* GraphKit::gen_checkcast(Node *obj, Node* superklass,
2967                               Node* *failure_control) {
2968   kill_dead_locals();           // Benefit all the uncommon traps
2969   const TypeKlassPtr *tk = _gvn.type(superklass)->is_klassptr();
2970   assert(tk->is_loaded(), "must be loaded");
2971   const Type *toop = TypeOopPtr::make_from_klass(tk->klass());
2972 
2973   // Fast cutout:  Check the case that the cast is vacuously true.
2974   // This detects the common cases where the test will short-circuit
2975   // away completely.  We do this before we perform the null check,
2976   // because if the test is going to turn into zero code, we don't
2977   // want a residual null check left around.  (Causes a slowdown,
2978   // for example, in some objArray manipulations, such as a[i]=a[j].)
2979   if (tk->singleton()) {
2980     const TypeOopPtr* objtp = _gvn.type(obj)->isa_oopptr();
2981     if (objtp != NULL && objtp->klass() != NULL) {
2982       switch (C->static_subtype_check(tk->klass(), objtp->klass())) {
2983       case Compile::SSC_always_true:
2984         // If we know the type check always succeed then we don't use
2985         // the profiling data at this bytecode. Don't lose it, feed it
2986         // to the type system as a speculative type.
2987         return record_profiled_receiver_for_speculation(obj);
2988       case Compile::SSC_always_false:
2989         // It needs a null check because a null will *pass* the cast check.
2990         // A non-null value will always produce an exception.
2991         return null_assert(obj);
2992       }
2993     }
2994   }
2995 
2996   ciProfileData* data = NULL;
2997   bool safe_for_replace = false;
2998   if (failure_control == NULL) {        // use MDO in regular case only
2999     assert(java_bc() == Bytecodes::_aastore ||
3000            java_bc() == Bytecodes::_checkcast,
3001            "interpreter profiles type checks only for these BCs");
3002     data = method()->method_data()->bci_to_data(bci());
3003     safe_for_replace = true;
3004   }
3005 
3006   // Make the merge point
3007   enum { _obj_path = 1, _null_path, PATH_LIMIT };
3008   RegionNode* region = new RegionNode(PATH_LIMIT);
3009   Node*       phi    = new PhiNode(region, toop);
3010   C->set_has_split_ifs(true); // Has chance for split-if optimization
3011 
3012   // Use null-cast information if it is available
3013   bool speculative_not_null = false;
3014   bool never_see_null = ((failure_control == NULL)  // regular case only
3015                          && seems_never_null(obj, data, speculative_not_null));
3016 
3017   // Null check; get casted pointer; set region slot 3
3018   Node* null_ctl = top();
3019   Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null, safe_for_replace, speculative_not_null);
3020 
3021   // If not_null_obj is dead, only null-path is taken
3022   if (stopped()) {              // Doing instance-of on a NULL?
3023     set_control(null_ctl);
3024     return null();
3025   }
3026   region->init_req(_null_path, null_ctl);
3027   phi   ->init_req(_null_path, null());  // Set null path value
3028   if (null_ctl == top()) {
3029     // Do this eagerly, so that pattern matches like is_diamond_phi
3030     // will work even during parsing.
3031     assert(_null_path == PATH_LIMIT-1, "delete last");
3032     region->del_req(_null_path);
3033     phi   ->del_req(_null_path);
3034   }
3035 
3036   Node* cast_obj = NULL;
3037   if (tk->klass_is_exact()) {
3038     // The following optimization tries to statically cast the speculative type of the object
3039     // (for example obtained during profiling) to the type of the superklass and then do a
3040     // dynamic check that the type of the object is what we expect. To work correctly
3041     // for checkcast and aastore the type of superklass should be exact.
3042     const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
3043     // We may not have profiling here or it may not help us. If we have
3044     // a speculative type use it to perform an exact cast.
3045     ciKlass* spec_obj_type = obj_type->speculative_type();
3046     if (spec_obj_type != NULL || data != NULL) {
3047       cast_obj = maybe_cast_profiled_receiver(not_null_obj, tk->klass(), spec_obj_type, safe_for_replace);
3048       if (cast_obj != NULL) {
3049         if (failure_control != NULL) // failure is now impossible
3050           (*failure_control) = top();
3051         // adjust the type of the phi to the exact klass:
3052         phi->raise_bottom_type(_gvn.type(cast_obj)->meet_speculative(TypePtr::NULL_PTR));
3053       }
3054     }
3055   }
3056 
3057   if (cast_obj == NULL) {
3058     // Load the object's klass
3059     Node* obj_klass = load_object_klass(not_null_obj);
3060 
3061     // Generate the subtype check
3062     Node* not_subtype_ctrl = gen_subtype_check( obj_klass, superklass );
3063 
3064     // Plug in success path into the merge
3065     cast_obj = _gvn.transform(new CheckCastPPNode(control(), not_null_obj, toop));
3066     // Failure path ends in uncommon trap (or may be dead - failure impossible)
3067     if (failure_control == NULL) {
3068       if (not_subtype_ctrl != top()) { // If failure is possible
3069         PreserveJVMState pjvms(this);
3070         set_control(not_subtype_ctrl);
3071         builtin_throw(Deoptimization::Reason_class_check, obj_klass);
3072       }
3073     } else {
3074       (*failure_control) = not_subtype_ctrl;
3075     }
3076   }
3077 
3078   region->init_req(_obj_path, control());
3079   phi   ->init_req(_obj_path, cast_obj);
3080 
3081   // A merge of NULL or Casted-NotNull obj
3082   Node* res = _gvn.transform(phi);
3083 
3084   // Note I do NOT always 'replace_in_map(obj,result)' here.
3085   //  if( tk->klass()->can_be_primary_super()  )
3086     // This means that if I successfully store an Object into an array-of-String
3087     // I 'forget' that the Object is really now known to be a String.  I have to
3088     // do this because we don't have true union types for interfaces - if I store
3089     // a Baz into an array-of-Interface and then tell the optimizer it's an
3090     // Interface, I forget that it's also a Baz and cannot do Baz-like field
3091     // references to it.  FIX THIS WHEN UNION TYPES APPEAR!
3092   //  replace_in_map( obj, res );
3093 
3094   // Return final merged results
3095   set_control( _gvn.transform(region) );
3096   record_for_igvn(region);
3097 
3098   return record_profiled_receiver_for_speculation(res);
3099 }
3100 
3101 //------------------------------next_monitor-----------------------------------
3102 // What number should be given to the next monitor?
3103 int GraphKit::next_monitor() {
3104   int current = jvms()->monitor_depth()* C->sync_stack_slots();
3105   int next = current + C->sync_stack_slots();
3106   // Keep the toplevel high water mark current:
3107   if (C->fixed_slots() < next)  C->set_fixed_slots(next);
3108   return current;
3109 }
3110 
3111 //------------------------------insert_mem_bar---------------------------------
3112 // Memory barrier to avoid floating things around
3113 // The membar serves as a pinch point between both control and all memory slices.
3114 Node* GraphKit::insert_mem_bar(int opcode, Node* precedent) {
3115   MemBarNode* mb = MemBarNode::make(C, opcode, Compile::AliasIdxBot, precedent);
3116   mb->init_req(TypeFunc::Control, control());
3117   mb->init_req(TypeFunc::Memory,  reset_memory());
3118   Node* membar = _gvn.transform(mb);
3119   set_control(_gvn.transform(new ProjNode(membar, TypeFunc::Control)));
3120   set_all_memory_call(membar);
3121   return membar;
3122 }
3123 
3124 //-------------------------insert_mem_bar_volatile----------------------------
3125 // Memory barrier to avoid floating things around
3126 // The membar serves as a pinch point between both control and memory(alias_idx).
3127 // If you want to make a pinch point on all memory slices, do not use this
3128 // function (even with AliasIdxBot); use insert_mem_bar() instead.
3129 Node* GraphKit::insert_mem_bar_volatile(int opcode, int alias_idx, Node* precedent) {
3130   // When Parse::do_put_xxx updates a volatile field, it appends a series
3131   // of MemBarVolatile nodes, one for *each* volatile field alias category.
3132   // The first membar is on the same memory slice as the field store opcode.
3133   // This forces the membar to follow the store.  (Bug 6500685 broke this.)
3134   // All the other membars (for other volatile slices, including AliasIdxBot,
3135   // which stands for all unknown volatile slices) are control-dependent
3136   // on the first membar.  This prevents later volatile loads or stores
3137   // from sliding up past the just-emitted store.
3138 
3139   MemBarNode* mb = MemBarNode::make(C, opcode, alias_idx, precedent);
3140   mb->set_req(TypeFunc::Control,control());
3141   if (alias_idx == Compile::AliasIdxBot) {
3142     mb->set_req(TypeFunc::Memory, merged_memory()->base_memory());
3143   } else {
3144     assert(!(opcode == Op_Initialize && alias_idx != Compile::AliasIdxRaw), "fix caller");
3145     mb->set_req(TypeFunc::Memory, memory(alias_idx));
3146   }
3147   Node* membar = _gvn.transform(mb);
3148   set_control(_gvn.transform(new ProjNode(membar, TypeFunc::Control)));
3149   if (alias_idx == Compile::AliasIdxBot) {
3150     merged_memory()->set_base_memory(_gvn.transform(new ProjNode(membar, TypeFunc::Memory)));
3151   } else {
3152     set_memory(_gvn.transform(new ProjNode(membar, TypeFunc::Memory)),alias_idx);
3153   }
3154   return membar;
3155 }
3156 
3157 //------------------------------shared_lock------------------------------------
3158 // Emit locking code.
3159 FastLockNode* GraphKit::shared_lock(Node* obj) {
3160   // bci is either a monitorenter bc or InvocationEntryBci
3161   // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
3162   assert(SynchronizationEntryBCI == InvocationEntryBci, "");
3163 
3164   if( !GenerateSynchronizationCode )
3165     return NULL;                // Not locking things?
3166   if (stopped())                // Dead monitor?
3167     return NULL;
3168 
3169   assert(dead_locals_are_killed(), "should kill locals before sync. point");
3170 
3171   // Box the stack location
3172   Node* box = _gvn.transform(new BoxLockNode(next_monitor()));
3173   Node* mem = reset_memory();
3174 
3175   FastLockNode * flock = _gvn.transform(new FastLockNode(0, obj, box) )->as_FastLock();
3176   if (UseBiasedLocking && PrintPreciseBiasedLockingStatistics) {
3177     // Create the counters for this fast lock.
3178     flock->create_lock_counter(sync_jvms()); // sync_jvms used to get current bci
3179   }
3180 
3181   // Create the rtm counters for this fast lock if needed.
3182   flock->create_rtm_lock_counter(sync_jvms()); // sync_jvms used to get current bci
3183 
3184   // Add monitor to debug info for the slow path.  If we block inside the
3185   // slow path and de-opt, we need the monitor hanging around
3186   map()->push_monitor( flock );
3187 
3188   const TypeFunc *tf = LockNode::lock_type();
3189   LockNode *lock = new LockNode(C, tf);
3190 
3191   lock->init_req( TypeFunc::Control, control() );
3192   lock->init_req( TypeFunc::Memory , mem );
3193   lock->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
3194   lock->init_req( TypeFunc::FramePtr, frameptr() );
3195   lock->init_req( TypeFunc::ReturnAdr, top() );
3196 
3197   lock->init_req(TypeFunc::Parms + 0, obj);
3198   lock->init_req(TypeFunc::Parms + 1, box);
3199   lock->init_req(TypeFunc::Parms + 2, flock);
3200   add_safepoint_edges(lock);
3201 
3202   lock = _gvn.transform( lock )->as_Lock();
3203 
3204   // lock has no side-effects, sets few values
3205   set_predefined_output_for_runtime_call(lock, mem, TypeRawPtr::BOTTOM);
3206 
3207   insert_mem_bar(Op_MemBarAcquireLock);
3208 
3209   // Add this to the worklist so that the lock can be eliminated
3210   record_for_igvn(lock);
3211 
3212 #ifndef PRODUCT
3213   if (PrintLockStatistics) {
3214     // Update the counter for this lock.  Don't bother using an atomic
3215     // operation since we don't require absolute accuracy.
3216     lock->create_lock_counter(map()->jvms());
3217     increment_counter(lock->counter()->addr());
3218   }
3219 #endif
3220 
3221   return flock;
3222 }
3223 
3224 
3225 //------------------------------shared_unlock----------------------------------
3226 // Emit unlocking code.
3227 void GraphKit::shared_unlock(Node* box, Node* obj) {
3228   // bci is either a monitorenter bc or InvocationEntryBci
3229   // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
3230   assert(SynchronizationEntryBCI == InvocationEntryBci, "");
3231 
3232   if( !GenerateSynchronizationCode )
3233     return;
3234   if (stopped()) {               // Dead monitor?
3235     map()->pop_monitor();        // Kill monitor from debug info
3236     return;
3237   }
3238 
3239   // Memory barrier to avoid floating things down past the locked region
3240   insert_mem_bar(Op_MemBarReleaseLock);
3241 
3242   const TypeFunc *tf = OptoRuntime::complete_monitor_exit_Type();
3243   UnlockNode *unlock = new UnlockNode(C, tf);
3244 #ifdef ASSERT
3245   unlock->set_dbg_jvms(sync_jvms());
3246 #endif
3247   uint raw_idx = Compile::AliasIdxRaw;
3248   unlock->init_req( TypeFunc::Control, control() );
3249   unlock->init_req( TypeFunc::Memory , memory(raw_idx) );
3250   unlock->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
3251   unlock->init_req( TypeFunc::FramePtr, frameptr() );
3252   unlock->init_req( TypeFunc::ReturnAdr, top() );
3253 
3254   unlock->init_req(TypeFunc::Parms + 0, obj);
3255   unlock->init_req(TypeFunc::Parms + 1, box);
3256   unlock = _gvn.transform(unlock)->as_Unlock();
3257 
3258   Node* mem = reset_memory();
3259 
3260   // unlock has no side-effects, sets few values
3261   set_predefined_output_for_runtime_call(unlock, mem, TypeRawPtr::BOTTOM);
3262 
3263   // Kill monitor from debug info
3264   map()->pop_monitor( );
3265 }
3266 
3267 //-------------------------------get_layout_helper-----------------------------
3268 // If the given klass is a constant or known to be an array,
3269 // fetch the constant layout helper value into constant_value
3270 // and return (Node*)NULL.  Otherwise, load the non-constant
3271 // layout helper value, and return the node which represents it.
3272 // This two-faced routine is useful because allocation sites
3273 // almost always feature constant types.
3274 Node* GraphKit::get_layout_helper(Node* klass_node, jint& constant_value) {
3275   const TypeKlassPtr* inst_klass = _gvn.type(klass_node)->isa_klassptr();
3276   if (!StressReflectiveCode && inst_klass != NULL) {
3277     ciKlass* klass = inst_klass->klass();
3278     assert(klass != NULL, "klass should not be NULL");
3279     bool    xklass = inst_klass->klass_is_exact();
3280     if (xklass || klass->is_array_klass()) {
3281       jint lhelper = klass->layout_helper();
3282       if (lhelper != Klass::_lh_neutral_value) {
3283         constant_value = lhelper;
3284         return (Node*) NULL;
3285       }
3286     }
3287   }
3288   constant_value = Klass::_lh_neutral_value;  // put in a known value
3289   Node* lhp = basic_plus_adr(klass_node, klass_node, in_bytes(Klass::layout_helper_offset()));
3290   return make_load(NULL, lhp, TypeInt::INT, T_INT, MemNode::unordered);
3291 }
3292 
3293 // We just put in an allocate/initialize with a big raw-memory effect.
3294 // Hook selected additional alias categories on the initialization.
3295 static void hook_memory_on_init(GraphKit& kit, int alias_idx,
3296                                 MergeMemNode* init_in_merge,
3297                                 Node* init_out_raw) {
3298   DEBUG_ONLY(Node* init_in_raw = init_in_merge->base_memory());
3299   assert(init_in_merge->memory_at(alias_idx) == init_in_raw, "");
3300 
3301   Node* prevmem = kit.memory(alias_idx);
3302   init_in_merge->set_memory_at(alias_idx, prevmem);
3303   kit.set_memory(init_out_raw, alias_idx);
3304 }
3305 
3306 //---------------------------set_output_for_allocation-------------------------
3307 Node* GraphKit::set_output_for_allocation(AllocateNode* alloc,
3308                                           const TypeOopPtr* oop_type,
3309                                           bool deoptimize_on_exception) {
3310   int rawidx = Compile::AliasIdxRaw;
3311   alloc->set_req( TypeFunc::FramePtr, frameptr() );
3312   add_safepoint_edges(alloc);
3313   Node* allocx = _gvn.transform(alloc);
3314   set_control( _gvn.transform(new ProjNode(allocx, TypeFunc::Control) ) );
3315   // create memory projection for i_o
3316   set_memory ( _gvn.transform( new ProjNode(allocx, TypeFunc::Memory, true) ), rawidx );
3317   make_slow_call_ex(allocx, env()->Throwable_klass(), true, deoptimize_on_exception);
3318 
3319   // create a memory projection as for the normal control path
3320   Node* malloc = _gvn.transform(new ProjNode(allocx, TypeFunc::Memory));
3321   set_memory(malloc, rawidx);
3322 
3323   // a normal slow-call doesn't change i_o, but an allocation does
3324   // we create a separate i_o projection for the normal control path
3325   set_i_o(_gvn.transform( new ProjNode(allocx, TypeFunc::I_O, false) ) );
3326   Node* rawoop = _gvn.transform( new ProjNode(allocx, TypeFunc::Parms) );
3327 
3328   // put in an initialization barrier
3329   InitializeNode* init = insert_mem_bar_volatile(Op_Initialize, rawidx,
3330                                                  rawoop)->as_Initialize();
3331   assert(alloc->initialization() == init,  "2-way macro link must work");
3332   assert(init ->allocation()     == alloc, "2-way macro link must work");
3333   {
3334     // Extract memory strands which may participate in the new object's
3335     // initialization, and source them from the new InitializeNode.
3336     // This will allow us to observe initializations when they occur,
3337     // and link them properly (as a group) to the InitializeNode.
3338     assert(init->in(InitializeNode::Memory) == malloc, "");
3339     MergeMemNode* minit_in = MergeMemNode::make(malloc);
3340     init->set_req(InitializeNode::Memory, minit_in);
3341     record_for_igvn(minit_in); // fold it up later, if possible
3342     Node* minit_out = memory(rawidx);
3343     assert(minit_out->is_Proj() && minit_out->in(0) == init, "");
3344     if (oop_type->isa_aryptr()) {
3345       const TypePtr* telemref = oop_type->add_offset(Type::OffsetBot);
3346       int            elemidx  = C->get_alias_index(telemref);
3347       hook_memory_on_init(*this, elemidx, minit_in, minit_out);
3348     } else if (oop_type->isa_instptr() || oop_type->isa_valuetypeptr()) {
3349       ciInstanceKlass* ik = oop_type->klass()->as_instance_klass();
3350       for (int i = 0, len = ik->nof_nonstatic_fields(); i < len; i++) {
3351         ciField* field = ik->nonstatic_field_at(i);
3352         if (field->offset() >= TrackedInitializationLimit * HeapWordSize)
3353           continue;  // do not bother to track really large numbers of fields
3354         // Find (or create) the alias category for this field:
3355         int fieldidx = C->alias_type(field)->index();
3356         hook_memory_on_init(*this, fieldidx, minit_in, minit_out);
3357       }
3358     }
3359   }
3360 
3361   // Cast raw oop to the real thing...
3362   Node* javaoop = new CheckCastPPNode(control(), rawoop, oop_type);
3363   javaoop = _gvn.transform(javaoop);
3364   C->set_recent_alloc(control(), javaoop);
3365   assert(just_allocated_object(control()) == javaoop, "just allocated");
3366 
3367 #ifdef ASSERT
3368   { // Verify that the AllocateNode::Ideal_allocation recognizers work:
3369     assert(AllocateNode::Ideal_allocation(rawoop, &_gvn) == alloc,
3370            "Ideal_allocation works");
3371     assert(AllocateNode::Ideal_allocation(javaoop, &_gvn) == alloc,
3372            "Ideal_allocation works");
3373     if (alloc->is_AllocateArray()) {
3374       assert(AllocateArrayNode::Ideal_array_allocation(rawoop, &_gvn) == alloc->as_AllocateArray(),
3375              "Ideal_allocation works");
3376       assert(AllocateArrayNode::Ideal_array_allocation(javaoop, &_gvn) == alloc->as_AllocateArray(),
3377              "Ideal_allocation works");
3378     } else {
3379       assert(alloc->in(AllocateNode::ALength)->is_top(), "no length, please");
3380     }
3381   }
3382 #endif //ASSERT
3383 
3384   return javaoop;
3385 }
3386 
3387 //---------------------------new_instance--------------------------------------
3388 // This routine takes a klass_node which may be constant (for a static type)
3389 // or may be non-constant (for reflective code).  It will work equally well
3390 // for either, and the graph will fold nicely if the optimizer later reduces
3391 // the type to a constant.
3392 // The optional arguments are for specialized use by intrinsics:
3393 //  - If 'extra_slow_test' if not null is an extra condition for the slow-path.
3394 //  - If 'return_size_val', report the the total object size to the caller.
3395 //  - deoptimize_on_exception controls how Java exceptions are handled (rethrow vs deoptimize)
3396 Node* GraphKit::new_instance(Node* klass_node,
3397                              Node* extra_slow_test,
3398                              Node* *return_size_val,
3399                              bool deoptimize_on_exception,
3400                              ValueTypeBaseNode* value_node) {
3401   // Compute size in doublewords
3402   // The size is always an integral number of doublewords, represented
3403   // as a positive bytewise size stored in the klass's layout_helper.
3404   // The layout_helper also encodes (in a low bit) the need for a slow path.
3405   jint  layout_con = Klass::_lh_neutral_value;
3406   Node* layout_val = get_layout_helper(klass_node, layout_con);
3407   bool  layout_is_con = (layout_val == NULL);
3408 
3409   if (extra_slow_test == NULL)  extra_slow_test = intcon(0);
3410   // Generate the initial go-slow test.  It's either ALWAYS (return a
3411   // Node for 1) or NEVER (return a NULL) or perhaps (in the reflective
3412   // case) a computed value derived from the layout_helper.
3413   Node* initial_slow_test = NULL;
3414   if (layout_is_con) {
3415     assert(!StressReflectiveCode, "stress mode does not use these paths");
3416     bool must_go_slow = Klass::layout_helper_needs_slow_path(layout_con);
3417     initial_slow_test = must_go_slow ? intcon(1) : extra_slow_test;
3418   } else {   // reflective case
3419     // This reflective path is used by Unsafe.allocateInstance.
3420     // (It may be stress-tested by specifying StressReflectiveCode.)
3421     // Basically, we want to get into the VM is there's an illegal argument.
3422     Node* bit = intcon(Klass::_lh_instance_slow_path_bit);
3423     initial_slow_test = _gvn.transform( new AndINode(layout_val, bit) );
3424     if (extra_slow_test != intcon(0)) {
3425       initial_slow_test = _gvn.transform( new OrINode(initial_slow_test, extra_slow_test) );
3426     }
3427     // (Macro-expander will further convert this to a Bool, if necessary.)
3428   }
3429 
3430   // Find the size in bytes.  This is easy; it's the layout_helper.
3431   // The size value must be valid even if the slow path is taken.
3432   Node* size = NULL;
3433   if (layout_is_con) {
3434     size = MakeConX(Klass::layout_helper_size_in_bytes(layout_con));
3435   } else {   // reflective case
3436     // This reflective path is used by clone and Unsafe.allocateInstance.
3437     size = ConvI2X(layout_val);
3438 
3439     // Clear the low bits to extract layout_helper_size_in_bytes:
3440     assert((int)Klass::_lh_instance_slow_path_bit < BytesPerLong, "clear bit");
3441     Node* mask = MakeConX(~ (intptr_t)right_n_bits(LogBytesPerLong));
3442     size = _gvn.transform( new AndXNode(size, mask) );
3443   }
3444   if (return_size_val != NULL) {
3445     (*return_size_val) = size;
3446   }
3447 
3448   // This is a precise notnull oop of the klass.
3449   // (Actually, it need not be precise if this is a reflective allocation.)
3450   // It's what we cast the result to.
3451   const TypeKlassPtr* tklass = _gvn.type(klass_node)->isa_klassptr();
3452   if (!tklass)  tklass = TypeKlassPtr::OBJECT;
3453   const TypeOopPtr* oop_type = tklass->as_instance_type();
3454 
3455   // Now generate allocation code
3456 
3457   // The entire memory state is needed for slow path of the allocation
3458   // since GC and deoptimization can happen.
3459   Node *mem = reset_memory();
3460   set_all_memory(mem); // Create new memory state
3461 
3462   AllocateNode* alloc = new AllocateNode(C, AllocateNode::alloc_type(Type::TOP),
3463                                          control(), mem, i_o(),
3464                                          size, klass_node,
3465                                          initial_slow_test, value_node);
3466 
3467   return set_output_for_allocation(alloc, oop_type, deoptimize_on_exception);
3468 }
3469 
3470 //-------------------------------new_array-------------------------------------
3471 // helper for newarray and anewarray
3472 // The 'length' parameter is (obviously) the length of the array.
3473 // See comments on new_instance for the meaning of the other arguments.
3474 Node* GraphKit::new_array(Node* klass_node,     // array klass (maybe variable)
3475                           Node* length,         // number of array elements
3476                           int   nargs,          // number of arguments to push back for uncommon trap
3477                           Node* *return_size_val,
3478                           bool deoptimize_on_exception) {
3479   jint  layout_con = Klass::_lh_neutral_value;
3480   Node* layout_val = get_layout_helper(klass_node, layout_con);
3481   bool  layout_is_con = (layout_val == NULL);
3482 
3483   if (!layout_is_con && !StressReflectiveCode &&
3484       !too_many_traps(Deoptimization::Reason_class_check)) {
3485     // This is a reflective array creation site.
3486     // Optimistically assume that it is a subtype of Object[],
3487     // so that we can fold up all the address arithmetic.
3488     layout_con = Klass::array_layout_helper(T_OBJECT);
3489     Node* cmp_lh = _gvn.transform( new CmpINode(layout_val, intcon(layout_con)) );
3490     Node* bol_lh = _gvn.transform( new BoolNode(cmp_lh, BoolTest::eq) );
3491     { BuildCutout unless(this, bol_lh, PROB_MAX);
3492       inc_sp(nargs);
3493       uncommon_trap(Deoptimization::Reason_class_check,
3494                     Deoptimization::Action_maybe_recompile);
3495     }
3496     layout_val = NULL;
3497     layout_is_con = true;
3498   }
3499 
3500   // Generate the initial go-slow test.  Make sure we do not overflow
3501   // if length is huge (near 2Gig) or negative!  We do not need
3502   // exact double-words here, just a close approximation of needed
3503   // double-words.  We can't add any offset or rounding bits, lest we
3504   // take a size -1 of bytes and make it positive.  Use an unsigned
3505   // compare, so negative sizes look hugely positive.
3506   int fast_size_limit = FastAllocateSizeLimit;
3507   if (layout_is_con) {
3508     assert(!StressReflectiveCode, "stress mode does not use these paths");
3509     // Increase the size limit if we have exact knowledge of array type.
3510     int log2_esize = Klass::layout_helper_log2_element_size(layout_con);
3511     fast_size_limit <<= (LogBytesPerLong - log2_esize);
3512   }
3513 
3514   Node* initial_slow_cmp  = _gvn.transform( new CmpUNode( length, intcon( fast_size_limit ) ) );
3515   Node* initial_slow_test = _gvn.transform( new BoolNode( initial_slow_cmp, BoolTest::gt ) );
3516 
3517   // --- Size Computation ---
3518   // array_size = round_to_heap(array_header + (length << elem_shift));
3519   // where round_to_heap(x) == align_to(x, MinObjAlignmentInBytes)
3520   // and align_to(x, y) == ((x + y-1) & ~(y-1))
3521   // The rounding mask is strength-reduced, if possible.
3522   int round_mask = MinObjAlignmentInBytes - 1;
3523   Node* header_size = NULL;
3524   int   header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
3525   // (T_BYTE has the weakest alignment and size restrictions...)
3526   if (layout_is_con) {
3527     int       hsize  = Klass::layout_helper_header_size(layout_con);
3528     int       eshift = Klass::layout_helper_log2_element_size(layout_con);
3529     BasicType etype  = Klass::layout_helper_element_type(layout_con);
3530     bool is_value_array = Klass::layout_helper_is_valueArray(layout_con);
3531     if ((round_mask & ~right_n_bits(eshift)) == 0)
3532       round_mask = 0;  // strength-reduce it if it goes away completely
3533     assert(is_value_array || (hsize & right_n_bits(eshift)) == 0, "hsize is pre-rounded");
3534     assert(header_size_min <= hsize, "generic minimum is smallest");
3535     header_size_min = hsize;
3536     header_size = intcon(hsize + round_mask);
3537   } else {
3538     Node* hss   = intcon(Klass::_lh_header_size_shift);
3539     Node* hsm   = intcon(Klass::_lh_header_size_mask);
3540     Node* hsize = _gvn.transform( new URShiftINode(layout_val, hss) );
3541     hsize       = _gvn.transform( new AndINode(hsize, hsm) );
3542     Node* mask  = intcon(round_mask);
3543     header_size = _gvn.transform( new AddINode(hsize, mask) );
3544   }
3545 
3546   Node* elem_shift = NULL;
3547   if (layout_is_con) {
3548     int eshift = Klass::layout_helper_log2_element_size(layout_con);
3549     if (eshift != 0)
3550       elem_shift = intcon(eshift);
3551   } else {
3552     // There is no need to mask or shift this value.
3553     // The semantics of LShiftINode include an implicit mask to 0x1F.
3554     assert(Klass::_lh_log2_element_size_shift == 0, "use shift in place");
3555     elem_shift = layout_val;
3556   }
3557 
3558   // Transition to native address size for all offset calculations:
3559   Node* lengthx = ConvI2X(length);
3560   Node* headerx = ConvI2X(header_size);
3561 #ifdef _LP64
3562   { const TypeInt* tilen = _gvn.find_int_type(length);
3563     if (tilen != NULL && tilen->_lo < 0) {
3564       // Add a manual constraint to a positive range.  Cf. array_element_address.
3565       jint size_max = fast_size_limit;
3566       if (size_max > tilen->_hi)  size_max = tilen->_hi;
3567       const TypeInt* tlcon = TypeInt::make(0, size_max, Type::WidenMin);
3568 
3569       // Only do a narrow I2L conversion if the range check passed.
3570       IfNode* iff = new IfNode(control(), initial_slow_test, PROB_MIN, COUNT_UNKNOWN);
3571       _gvn.transform(iff);
3572       RegionNode* region = new RegionNode(3);
3573       _gvn.set_type(region, Type::CONTROL);
3574       lengthx = new PhiNode(region, TypeLong::LONG);
3575       _gvn.set_type(lengthx, TypeLong::LONG);
3576 
3577       // Range check passed. Use ConvI2L node with narrow type.
3578       Node* passed = IfFalse(iff);
3579       region->init_req(1, passed);
3580       // Make I2L conversion control dependent to prevent it from
3581       // floating above the range check during loop optimizations.
3582       lengthx->init_req(1, C->constrained_convI2L(&_gvn, length, tlcon, passed));
3583 
3584       // Range check failed. Use ConvI2L with wide type because length may be invalid.
3585       region->init_req(2, IfTrue(iff));
3586       lengthx->init_req(2, ConvI2X(length));
3587 
3588       set_control(region);
3589       record_for_igvn(region);
3590       record_for_igvn(lengthx);
3591     }
3592   }
3593 #endif
3594 
3595   // Combine header size (plus rounding) and body size.  Then round down.
3596   // This computation cannot overflow, because it is used only in two
3597   // places, one where the length is sharply limited, and the other
3598   // after a successful allocation.
3599   Node* abody = lengthx;
3600   if (elem_shift != NULL)
3601     abody     = _gvn.transform( new LShiftXNode(lengthx, elem_shift) );
3602   Node* size  = _gvn.transform( new AddXNode(headerx, abody) );
3603   if (round_mask != 0) {
3604     Node* mask = MakeConX(~round_mask);
3605     size       = _gvn.transform( new AndXNode(size, mask) );
3606   }
3607   // else if round_mask == 0, the size computation is self-rounding
3608 
3609   if (return_size_val != NULL) {
3610     // This is the size
3611     (*return_size_val) = size;
3612   }
3613 
3614   // Now generate allocation code
3615 
3616   // The entire memory state is needed for slow path of the allocation
3617   // since GC and deoptimization can happen.
3618   Node *mem = reset_memory();
3619   set_all_memory(mem); // Create new memory state
3620 
3621   if (initial_slow_test->is_Bool()) {
3622     // Hide it behind a CMoveI, or else PhaseIdealLoop::split_up will get sick.
3623     initial_slow_test = initial_slow_test->as_Bool()->as_int_value(&_gvn);
3624   }
3625 
3626   // Create the AllocateArrayNode and its result projections
3627   AllocateArrayNode* alloc
3628     = new AllocateArrayNode(C, AllocateArrayNode::alloc_type(TypeInt::INT),
3629                             control(), mem, i_o(),
3630                             size, klass_node,
3631                             initial_slow_test,
3632                             length);
3633 
3634   // Cast to correct type.  Note that the klass_node may be constant or not,
3635   // and in the latter case the actual array type will be inexact also.
3636   // (This happens via a non-constant argument to inline_native_newArray.)
3637   // In any case, the value of klass_node provides the desired array type.
3638   const TypeInt* length_type = _gvn.find_int_type(length);
3639   const TypeOopPtr* ary_type = _gvn.type(klass_node)->is_klassptr()->as_instance_type();
3640   if (ary_type->isa_aryptr() && length_type != NULL) {
3641     // Try to get a better type than POS for the size
3642     ary_type = ary_type->is_aryptr()->cast_to_size(length_type);
3643   }
3644 
3645   Node* javaoop = set_output_for_allocation(alloc, ary_type, deoptimize_on_exception);
3646 
3647   // Cast length on remaining path to be as narrow as possible
3648   if (map()->find_edge(length) >= 0) {
3649     Node* ccast = alloc->make_ideal_length(ary_type, &_gvn);
3650     if (ccast != length) {
3651       _gvn.set_type_bottom(ccast);
3652       record_for_igvn(ccast);
3653       replace_in_map(length, ccast);
3654     }
3655   }
3656 
3657   const TypeAryPtr* ary_ptr = ary_type->isa_aryptr();
3658   ciKlass* elem_klass = ary_ptr != NULL ? ary_ptr->klass()->as_array_klass()->element_klass() : NULL;
3659   if (elem_klass != NULL && elem_klass->is_valuetype()) {
3660     ciValueKlass* vk = elem_klass->as_value_klass();
3661     if (!vk->flatten_array()) {
3662       // Non-flattened value type arrays need to be initialized with default value type oops
3663       initialize_value_type_array(javaoop, length, elem_klass->as_value_klass(), nargs);
3664       InitializeNode* init = alloc->initialization();
3665       init->set_complete_with_arraycopy();
3666     }
3667   }
3668 
3669   return javaoop;
3670 }
3671 
3672 void GraphKit::initialize_value_type_array(Node* array, Node* length, ciValueKlass* vk, int nargs) {
3673   // Check for zero length
3674   Node* null_ctl = top();
3675   null_check_common(length, T_INT, false, &null_ctl, false);
3676   if (stopped()) {
3677     set_control(null_ctl); // Always zero
3678     return;
3679   }
3680 
3681   // Prepare for merging control and IO
3682   RegionNode* res_ctl = new RegionNode(3);
3683   res_ctl->init_req(1, null_ctl);
3684   gvn().set_type(res_ctl, Type::CONTROL);
3685   record_for_igvn(res_ctl);
3686   Node* res_io = PhiNode::make(res_ctl, i_o(), Type::ABIO);
3687   gvn().set_type(res_io, Type::ABIO);
3688   record_for_igvn(res_io);
3689 
3690   // TODO comment
3691   SafePointNode* loop_map = NULL;
3692   {
3693     PreserveJVMState pjvms(this);
3694     // Create default value type and store it to memory
3695     Node* oop = ValueTypeNode::make_default(gvn(), vk);
3696     oop = oop->as_ValueType()->allocate(this)->get_oop();
3697 
3698     length = SubI(length, intcon(1));
3699     add_predicate(nargs);
3700     RegionNode* loop = new RegionNode(3);
3701     loop->init_req(1, control());
3702     gvn().set_type(loop, Type::CONTROL);
3703     record_for_igvn(loop);
3704 
3705     Node* index = new PhiNode(loop, TypeInt::INT);
3706     index->init_req(1, intcon(0));
3707     gvn().set_type(index, TypeInt::INT);
3708     record_for_igvn(index);
3709 
3710     // TODO explain why we need to capture all memory
3711     PhiNode* mem = new PhiNode(loop, Type::MEMORY, TypePtr::BOTTOM);
3712     mem->init_req(1, reset_memory());
3713     gvn().set_type(mem, Type::MEMORY);
3714     record_for_igvn(mem);
3715     set_control(loop);
3716     set_all_memory(mem);
3717     // Initialize array element
3718     Node* adr = array_element_address(array, index, T_OBJECT);
3719     const TypeOopPtr* elemtype = TypeValueTypePtr::make(TypePtr::NotNull, vk);
3720     Node* store = store_oop_to_array(control(), array, adr, TypeAryPtr::OOPS, oop, elemtype, T_OBJECT, MemNode::release);
3721 
3722     IfNode* iff = create_and_map_if(control(), Bool(CmpI(index, length), BoolTest::lt), PROB_FAIR, COUNT_UNKNOWN);
3723     loop->init_req(2, IfTrue(iff));
3724     mem->init_req(2, merged_memory());
3725     index->init_req(2, AddI(index, intcon(1)));
3726 
3727     res_ctl->init_req(2, IfFalse(iff));
3728     res_io->set_req(2, i_o());
3729     loop_map = stop();
3730   }
3731   // Set merged control, IO and memory
3732   set_control(res_ctl);
3733   set_i_o(res_io);
3734   merge_memory(loop_map->merged_memory(), res_ctl, 2);
3735 
3736   // Transform new memory Phis.
3737   for (MergeMemStream mms(merged_memory()); mms.next_non_empty();) {
3738     Node* phi = mms.memory();
3739     if (phi->is_Phi() && phi->in(0) == res_ctl) {
3740       mms.set_memory(gvn().transform(phi));
3741     }
3742   }
3743 }
3744 
3745 // The following "Ideal_foo" functions are placed here because they recognize
3746 // the graph shapes created by the functions immediately above.
3747 
3748 //---------------------------Ideal_allocation----------------------------------
3749 // Given an oop pointer or raw pointer, see if it feeds from an AllocateNode.
3750 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase) {
3751   if (ptr == NULL) {     // reduce dumb test in callers
3752     return NULL;
3753   }
3754   if (ptr->is_CheckCastPP()) { // strip only one raw-to-oop cast
3755     ptr = ptr->in(1);
3756     if (ptr == NULL) return NULL;
3757   }
3758   // Return NULL for allocations with several casts:
3759   //   j.l.reflect.Array.newInstance(jobject, jint)
3760   //   Object.clone()
3761   // to keep more precise type from last cast.
3762   if (ptr->is_Proj()) {
3763     Node* allo = ptr->in(0);
3764     if (allo != NULL && allo->is_Allocate()) {
3765       return allo->as_Allocate();
3766     }
3767   }
3768   // Report failure to match.
3769   return NULL;
3770 }
3771 
3772 // Fancy version which also strips off an offset (and reports it to caller).
3773 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase,
3774                                              intptr_t& offset) {
3775   Node* base = AddPNode::Ideal_base_and_offset(ptr, phase, offset);
3776   if (base == NULL)  return NULL;
3777   return Ideal_allocation(base, phase);
3778 }
3779 
3780 // Trace Initialize <- Proj[Parm] <- Allocate
3781 AllocateNode* InitializeNode::allocation() {
3782   Node* rawoop = in(InitializeNode::RawAddress);
3783   if (rawoop->is_Proj()) {
3784     Node* alloc = rawoop->in(0);
3785     if (alloc->is_Allocate()) {
3786       return alloc->as_Allocate();
3787     }
3788   }
3789   return NULL;
3790 }
3791 
3792 // Trace Allocate -> Proj[Parm] -> Initialize
3793 InitializeNode* AllocateNode::initialization() {
3794   ProjNode* rawoop = proj_out(AllocateNode::RawAddress);
3795   if (rawoop == NULL)  return NULL;
3796   for (DUIterator_Fast imax, i = rawoop->fast_outs(imax); i < imax; i++) {
3797     Node* init = rawoop->fast_out(i);
3798     if (init->is_Initialize()) {
3799       assert(init->as_Initialize()->allocation() == this, "2-way link");
3800       return init->as_Initialize();
3801     }
3802   }
3803   return NULL;
3804 }
3805 
3806 //----------------------------- loop predicates ---------------------------
3807 
3808 //------------------------------add_predicate_impl----------------------------
3809 void GraphKit::add_predicate_impl(Deoptimization::DeoptReason reason, int nargs) {
3810   // Too many traps seen?
3811   if (too_many_traps(reason)) {
3812 #ifdef ASSERT
3813     if (TraceLoopPredicate) {
3814       int tc = C->trap_count(reason);
3815       tty->print("too many traps=%s tcount=%d in ",
3816                     Deoptimization::trap_reason_name(reason), tc);
3817       method()->print(); // which method has too many predicate traps
3818       tty->cr();
3819     }
3820 #endif
3821     // We cannot afford to take more traps here,
3822     // do not generate predicate.
3823     return;
3824   }
3825 
3826   Node *cont    = _gvn.intcon(1);
3827   Node* opq     = _gvn.transform(new Opaque1Node(C, cont));
3828   Node *bol     = _gvn.transform(new Conv2BNode(opq));
3829   IfNode* iff   = create_and_map_if(control(), bol, PROB_MAX, COUNT_UNKNOWN);
3830   Node* iffalse = _gvn.transform(new IfFalseNode(iff));
3831   C->add_predicate_opaq(opq);
3832   {
3833     PreserveJVMState pjvms(this);
3834     set_control(iffalse);
3835     inc_sp(nargs);
3836     uncommon_trap(reason, Deoptimization::Action_maybe_recompile);
3837   }
3838   Node* iftrue = _gvn.transform(new IfTrueNode(iff));
3839   set_control(iftrue);
3840 }
3841 
3842 //------------------------------add_predicate---------------------------------
3843 void GraphKit::add_predicate(int nargs) {
3844   if (UseLoopPredicate) {
3845     add_predicate_impl(Deoptimization::Reason_predicate, nargs);
3846   }
3847   // loop's limit check predicate should be near the loop.
3848   add_predicate_impl(Deoptimization::Reason_loop_limit_check, nargs);
3849 }
3850 
3851 //----------------------------- store barriers ----------------------------
3852 #define __ ideal.
3853 
3854 void GraphKit::sync_kit(IdealKit& ideal) {
3855   set_all_memory(__ merged_memory());
3856   set_i_o(__ i_o());
3857   set_control(__ ctrl());
3858 }
3859 
3860 void GraphKit::final_sync(IdealKit& ideal) {
3861   // Final sync IdealKit and graphKit.
3862   sync_kit(ideal);
3863 }
3864 
3865 Node* GraphKit::byte_map_base_node() {
3866   // Get base of card map
3867   CardTableModRefBS* ct =
3868     barrier_set_cast<CardTableModRefBS>(Universe::heap()->barrier_set());
3869   assert(sizeof(*ct->byte_map_base) == sizeof(jbyte), "adjust users of this code");
3870   if (ct->byte_map_base != NULL) {
3871     return makecon(TypeRawPtr::make((address)ct->byte_map_base));
3872   } else {
3873     return null();
3874   }
3875 }
3876 
3877 // vanilla/CMS post barrier
3878 // Insert a write-barrier store.  This is to let generational GC work; we have
3879 // to flag all oop-stores before the next GC point.
3880 void GraphKit::write_barrier_post(Node* oop_store,
3881                                   Node* obj,
3882                                   Node* adr,
3883                                   uint  adr_idx,
3884                                   Node* val,
3885                                   bool use_precise) {
3886   // No store check needed if we're storing a NULL or an old object
3887   // (latter case is probably a string constant). The concurrent
3888   // mark sweep garbage collector, however, needs to have all nonNull
3889   // oop updates flagged via card-marks.
3890   if (val != NULL && val->is_Con()) {
3891     // must be either an oop or NULL
3892     const Type* t = val->bottom_type();
3893     if (t == TypePtr::NULL_PTR || t == Type::TOP)
3894       // stores of null never (?) need barriers
3895       return;
3896   }
3897 
3898   if (use_ReduceInitialCardMarks()
3899       && obj == just_allocated_object(control())) {
3900     // We can skip marks on a freshly-allocated object in Eden.
3901     // Keep this code in sync with new_store_pre_barrier() in runtime.cpp.
3902     // That routine informs GC to take appropriate compensating steps,
3903     // upon a slow-path allocation, so as to make this card-mark
3904     // elision safe.
3905     return;
3906   }
3907 
3908   if (!use_precise) {
3909     // All card marks for a (non-array) instance are in one place:
3910     adr = obj;
3911   }
3912   // (Else it's an array (or unknown), and we want more precise card marks.)
3913   assert(adr != NULL, "");
3914 
3915   IdealKit ideal(this, true);
3916 
3917   // Convert the pointer to an int prior to doing math on it
3918   Node* cast = __ CastPX(__ ctrl(), adr);
3919 
3920   // Divide by card size
3921   assert(Universe::heap()->barrier_set()->is_a(BarrierSet::CardTableModRef),
3922          "Only one we handle so far.");
3923   Node* card_offset = __ URShiftX( cast, __ ConI(CardTableModRefBS::card_shift) );
3924 
3925   // Combine card table base and card offset
3926   Node* card_adr = __ AddP(__ top(), byte_map_base_node(), card_offset );
3927 
3928   // Get the alias_index for raw card-mark memory
3929   int adr_type = Compile::AliasIdxRaw;
3930   Node*   zero = __ ConI(0); // Dirty card value
3931   BasicType bt = T_BYTE;
3932 
3933   if (UseConcMarkSweepGC && UseCondCardMark) {
3934     insert_mem_bar(Op_MemBarVolatile);   // StoreLoad barrier
3935     __ sync_kit(this);
3936   }
3937 
3938   if (UseCondCardMark) {
3939     // The classic GC reference write barrier is typically implemented
3940     // as a store into the global card mark table.  Unfortunately
3941     // unconditional stores can result in false sharing and excessive
3942     // coherence traffic as well as false transactional aborts.
3943     // UseCondCardMark enables MP "polite" conditional card mark
3944     // stores.  In theory we could relax the load from ctrl() to
3945     // no_ctrl, but that doesn't buy much latitude.
3946     Node* card_val = __ load( __ ctrl(), card_adr, TypeInt::BYTE, bt, adr_type);
3947     __ if_then(card_val, BoolTest::ne, zero);
3948   }
3949 
3950   // Smash zero into card
3951   if( !UseConcMarkSweepGC ) {
3952     __ store(__ ctrl(), card_adr, zero, bt, adr_type, MemNode::unordered);
3953   } else {
3954     // Specialized path for CM store barrier
3955     __ storeCM(__ ctrl(), card_adr, zero, oop_store, adr_idx, bt, adr_type);
3956   }
3957 
3958   if (UseCondCardMark) {
3959     __ end_if();
3960   }
3961 
3962   // Final sync IdealKit and GraphKit.
3963   final_sync(ideal);
3964 }
3965 /*
3966  * Determine if the G1 pre-barrier can be removed. The pre-barrier is
3967  * required by SATB to make sure all objects live at the start of the
3968  * marking are kept alive, all reference updates need to any previous
3969  * reference stored before writing.
3970  *
3971  * If the previous value is NULL there is no need to save the old value.
3972  * References that are NULL are filtered during runtime by the barrier
3973  * code to avoid unnecessary queuing.
3974  *
3975  * However in the case of newly allocated objects it might be possible to
3976  * prove that the reference about to be overwritten is NULL during compile
3977  * time and avoid adding the barrier code completely.
3978  *
3979  * The compiler needs to determine that the object in which a field is about
3980  * to be written is newly allocated, and that no prior store to the same field
3981  * has happened since the allocation.
3982  *
3983  * Returns true if the pre-barrier can be removed
3984  */
3985 bool GraphKit::g1_can_remove_pre_barrier(PhaseTransform* phase, Node* adr,
3986                                          BasicType bt, uint adr_idx) {
3987   intptr_t offset = 0;
3988   Node* base = AddPNode::Ideal_base_and_offset(adr, phase, offset);
3989   AllocateNode* alloc = AllocateNode::Ideal_allocation(base, phase);
3990 
3991   if (offset == Type::OffsetBot) {
3992     return false; // cannot unalias unless there are precise offsets
3993   }
3994 
3995   if (alloc == NULL) {
3996     return false; // No allocation found
3997   }
3998 
3999   intptr_t size_in_bytes = type2aelembytes(bt);
4000 
4001   Node* mem = memory(adr_idx); // start searching here...
4002 
4003   for (int cnt = 0; cnt < 50; cnt++) {
4004 
4005     if (mem->is_Store()) {
4006 
4007       Node* st_adr = mem->in(MemNode::Address);
4008       intptr_t st_offset = 0;
4009       Node* st_base = AddPNode::Ideal_base_and_offset(st_adr, phase, st_offset);
4010 
4011       if (st_base == NULL) {
4012         break; // inscrutable pointer
4013       }
4014 
4015       // Break we have found a store with same base and offset as ours so break
4016       if (st_base == base && st_offset == offset) {
4017         break;
4018       }
4019 
4020       if (st_offset != offset && st_offset != Type::OffsetBot) {
4021         const int MAX_STORE = BytesPerLong;
4022         if (st_offset >= offset + size_in_bytes ||
4023             st_offset <= offset - MAX_STORE ||
4024             st_offset <= offset - mem->as_Store()->memory_size()) {
4025           // Success:  The offsets are provably independent.
4026           // (You may ask, why not just test st_offset != offset and be done?
4027           // The answer is that stores of different sizes can co-exist
4028           // in the same sequence of RawMem effects.  We sometimes initialize
4029           // a whole 'tile' of array elements with a single jint or jlong.)
4030           mem = mem->in(MemNode::Memory);
4031           continue; // advance through independent store memory
4032         }
4033       }
4034 
4035       if (st_base != base
4036           && MemNode::detect_ptr_independence(base, alloc, st_base,
4037                                               AllocateNode::Ideal_allocation(st_base, phase),
4038                                               phase)) {
4039         // Success:  The bases are provably independent.
4040         mem = mem->in(MemNode::Memory);
4041         continue; // advance through independent store memory
4042       }
4043     } else if (mem->is_Proj() && mem->in(0)->is_Initialize()) {
4044 
4045       InitializeNode* st_init = mem->in(0)->as_Initialize();
4046       AllocateNode* st_alloc = st_init->allocation();
4047 
4048       // Make sure that we are looking at the same allocation site.
4049       // The alloc variable is guaranteed to not be null here from earlier check.
4050       if (alloc == st_alloc) {
4051         // Check that the initialization is storing NULL so that no previous store
4052         // has been moved up and directly write a reference
4053         Node* captured_store = st_init->find_captured_store(offset,
4054                                                             type2aelembytes(T_OBJECT),
4055                                                             phase);
4056         if (captured_store == NULL || captured_store == st_init->zero_memory()) {
4057           return true;
4058         }
4059       }
4060     }
4061 
4062     // Unless there is an explicit 'continue', we must bail out here,
4063     // because 'mem' is an inscrutable memory state (e.g., a call).
4064     break;
4065   }
4066 
4067   return false;
4068 }
4069 
4070 // G1 pre/post barriers
4071 void GraphKit::g1_write_barrier_pre(bool do_load,
4072                                     Node* obj,
4073                                     Node* adr,
4074                                     uint alias_idx,
4075                                     Node* val,
4076                                     const TypeOopPtr* val_type,
4077                                     Node* pre_val,
4078                                     BasicType bt) {
4079 
4080   // Some sanity checks
4081   // Note: val is unused in this routine.
4082 
4083   if (do_load) {
4084     // We need to generate the load of the previous value
4085     assert(obj != NULL, "must have a base");
4086     assert(adr != NULL, "where are loading from?");
4087     assert(pre_val == NULL, "loaded already?");
4088     assert(val_type != NULL, "need a type");
4089 
4090     if (use_ReduceInitialCardMarks()
4091         && g1_can_remove_pre_barrier(&_gvn, adr, bt, alias_idx)) {
4092       return;
4093     }
4094 
4095   } else {
4096     // In this case both val_type and alias_idx are unused.
4097     assert(pre_val != NULL, "must be loaded already");
4098     // Nothing to be done if pre_val is null.
4099     if (pre_val->bottom_type() == TypePtr::NULL_PTR) return;
4100     assert(pre_val->bottom_type()->basic_type() == T_OBJECT, "or we shouldn't be here");
4101   }
4102   assert(bt == T_OBJECT || bt == T_VALUETYPE, "or we shouldn't be here");
4103 
4104   IdealKit ideal(this, true);
4105 
4106   Node* tls = __ thread(); // ThreadLocalStorage
4107 
4108   Node* no_ctrl = NULL;
4109   Node* no_base = __ top();
4110   Node* zero  = __ ConI(0);
4111   Node* zeroX = __ ConX(0);
4112 
4113   float likely  = PROB_LIKELY(0.999);
4114   float unlikely  = PROB_UNLIKELY(0.999);
4115 
4116   BasicType active_type = in_bytes(SATBMarkQueue::byte_width_of_active()) == 4 ? T_INT : T_BYTE;
4117   assert(in_bytes(SATBMarkQueue::byte_width_of_active()) == 4 || in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "flag width");
4118 
4119   // Offsets into the thread
4120   const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() +  // 648
4121                                           SATBMarkQueue::byte_offset_of_active());
4122   const int index_offset   = in_bytes(JavaThread::satb_mark_queue_offset() +  // 656
4123                                           SATBMarkQueue::byte_offset_of_index());
4124   const int buffer_offset  = in_bytes(JavaThread::satb_mark_queue_offset() +  // 652
4125                                           SATBMarkQueue::byte_offset_of_buf());
4126 
4127   // Now the actual pointers into the thread
4128   Node* marking_adr = __ AddP(no_base, tls, __ ConX(marking_offset));
4129   Node* buffer_adr  = __ AddP(no_base, tls, __ ConX(buffer_offset));
4130   Node* index_adr   = __ AddP(no_base, tls, __ ConX(index_offset));
4131 
4132   // Now some of the values
4133   Node* marking = __ load(__ ctrl(), marking_adr, TypeInt::INT, active_type, Compile::AliasIdxRaw);
4134 
4135   // if (!marking)
4136   __ if_then(marking, BoolTest::ne, zero, unlikely); {
4137     BasicType index_bt = TypeX_X->basic_type();
4138     assert(sizeof(size_t) == type2aelembytes(index_bt), "Loading G1 SATBMarkQueue::_index with wrong size.");
4139     Node* index   = __ load(__ ctrl(), index_adr, TypeX_X, index_bt, Compile::AliasIdxRaw);
4140 
4141     if (do_load) {
4142       // load original value
4143       // alias_idx correct??
4144       pre_val = __ load(__ ctrl(), adr, val_type, bt, alias_idx);
4145     }
4146 
4147     // if (pre_val != NULL)
4148     __ if_then(pre_val, BoolTest::ne, null()); {
4149       Node* buffer  = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
4150 
4151       // is the queue for this thread full?
4152       __ if_then(index, BoolTest::ne, zeroX, likely); {
4153 
4154         // decrement the index
4155         Node* next_index = _gvn.transform(new SubXNode(index, __ ConX(sizeof(intptr_t))));
4156 
4157         // Now get the buffer location we will log the previous value into and store it
4158         Node *log_addr = __ AddP(no_base, buffer, next_index);
4159         __ store(__ ctrl(), log_addr, pre_val, T_OBJECT, Compile::AliasIdxRaw, MemNode::unordered);
4160         // update the index
4161         __ store(__ ctrl(), index_adr, next_index, index_bt, Compile::AliasIdxRaw, MemNode::unordered);
4162 
4163       } __ else_(); {
4164 
4165         // logging buffer is full, call the runtime
4166         const TypeFunc *tf = OptoRuntime::g1_wb_pre_Type();
4167         __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_pre), "g1_wb_pre", pre_val, tls);
4168       } __ end_if();  // (!index)
4169     } __ end_if();  // (pre_val != NULL)
4170   } __ end_if();  // (!marking)
4171 
4172   // Final sync IdealKit and GraphKit.
4173   final_sync(ideal);
4174 }
4175 
4176 /*
4177  * G1 similar to any GC with a Young Generation requires a way to keep track of
4178  * references from Old Generation to Young Generation to make sure all live
4179  * objects are found. G1 also requires to keep track of object references
4180  * between different regions to enable evacuation of old regions, which is done
4181  * as part of mixed collections. References are tracked in remembered sets and
4182  * is continuously updated as reference are written to with the help of the
4183  * post-barrier.
4184  *
4185  * To reduce the number of updates to the remembered set the post-barrier
4186  * filters updates to fields in objects located in the Young Generation,
4187  * the same region as the reference, when the NULL is being written or
4188  * if the card is already marked as dirty by an earlier write.
4189  *
4190  * Under certain circumstances it is possible to avoid generating the
4191  * post-barrier completely if it is possible during compile time to prove
4192  * the object is newly allocated and that no safepoint exists between the
4193  * allocation and the store.
4194  *
4195  * In the case of slow allocation the allocation code must handle the barrier
4196  * as part of the allocation in the case the allocated object is not located
4197  * in the nursery, this would happen for humongous objects. This is similar to
4198  * how CMS is required to handle this case, see the comments for the method
4199  * CollectedHeap::new_store_pre_barrier and OptoRuntime::new_store_pre_barrier.
4200  * A deferred card mark is required for these objects and handled in the above
4201  * mentioned methods.
4202  *
4203  * Returns true if the post barrier can be removed
4204  */
4205 bool GraphKit::g1_can_remove_post_barrier(PhaseTransform* phase, Node* store,
4206                                           Node* adr) {
4207   intptr_t      offset = 0;
4208   Node*         base   = AddPNode::Ideal_base_and_offset(adr, phase, offset);
4209   AllocateNode* alloc  = AllocateNode::Ideal_allocation(base, phase);
4210 
4211   if (offset == Type::OffsetBot) {
4212     return false; // cannot unalias unless there are precise offsets
4213   }
4214 
4215   if (alloc == NULL) {
4216      return false; // No allocation found
4217   }
4218 
4219   // Start search from Store node
4220   Node* mem = store->in(MemNode::Control);
4221   if (mem->is_Proj() && mem->in(0)->is_Initialize()) {
4222 
4223     InitializeNode* st_init = mem->in(0)->as_Initialize();
4224     AllocateNode*  st_alloc = st_init->allocation();
4225 
4226     // Make sure we are looking at the same allocation
4227     if (alloc == st_alloc) {
4228       return true;
4229     }
4230   }
4231 
4232   return false;
4233 }
4234 
4235 //
4236 // Update the card table and add card address to the queue
4237 //
4238 void GraphKit::g1_mark_card(IdealKit& ideal,
4239                             Node* card_adr,
4240                             Node* oop_store,
4241                             uint oop_alias_idx,
4242                             Node* index,
4243                             Node* index_adr,
4244                             Node* buffer,
4245                             const TypeFunc* tf) {
4246 
4247   Node* zero  = __ ConI(0);
4248   Node* zeroX = __ ConX(0);
4249   Node* no_base = __ top();
4250   BasicType card_bt = T_BYTE;
4251   // Smash zero into card. MUST BE ORDERED WRT TO STORE
4252   __ storeCM(__ ctrl(), card_adr, zero, oop_store, oop_alias_idx, card_bt, Compile::AliasIdxRaw);
4253 
4254   //  Now do the queue work
4255   __ if_then(index, BoolTest::ne, zeroX); {
4256 
4257     Node* next_index = _gvn.transform(new SubXNode(index, __ ConX(sizeof(intptr_t))));
4258     Node* log_addr = __ AddP(no_base, buffer, next_index);
4259 
4260     // Order, see storeCM.
4261     __ store(__ ctrl(), log_addr, card_adr, T_ADDRESS, Compile::AliasIdxRaw, MemNode::unordered);
4262     __ store(__ ctrl(), index_adr, next_index, TypeX_X->basic_type(), Compile::AliasIdxRaw, MemNode::unordered);
4263 
4264   } __ else_(); {
4265     __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_post), "g1_wb_post", card_adr, __ thread());
4266   } __ end_if();
4267 
4268 }
4269 
4270 void GraphKit::g1_write_barrier_post(Node* oop_store,
4271                                      Node* obj,
4272                                      Node* adr,
4273                                      uint alias_idx,
4274                                      Node* val,
4275                                      BasicType bt,
4276                                      bool use_precise) {
4277   // If we are writing a NULL then we need no post barrier
4278 
4279   if (val != NULL && val->is_Con() && val->bottom_type() == TypePtr::NULL_PTR) {
4280     // Must be NULL
4281     const Type* t = val->bottom_type();
4282     assert(t == Type::TOP || t == TypePtr::NULL_PTR, "must be NULL");
4283     // No post barrier if writing NULLx
4284     return;
4285   }
4286 
4287   if (use_ReduceInitialCardMarks() && obj == just_allocated_object(control())) {
4288     // We can skip marks on a freshly-allocated object in Eden.
4289     // Keep this code in sync with new_store_pre_barrier() in runtime.cpp.
4290     // That routine informs GC to take appropriate compensating steps,
4291     // upon a slow-path allocation, so as to make this card-mark
4292     // elision safe.
4293     return;
4294   }
4295 
4296   if (use_ReduceInitialCardMarks()
4297       && g1_can_remove_post_barrier(&_gvn, oop_store, adr)) {
4298     return;
4299   }
4300 
4301   if (!use_precise) {
4302     // All card marks for a (non-array) instance are in one place:
4303     adr = obj;
4304   }
4305   // (Else it's an array (or unknown), and we want more precise card marks.)
4306   assert(adr != NULL, "");
4307 
4308   IdealKit ideal(this, true);
4309 
4310   Node* tls = __ thread(); // ThreadLocalStorage
4311 
4312   Node* no_base = __ top();
4313   float likely  = PROB_LIKELY(0.999);
4314   float unlikely  = PROB_UNLIKELY(0.999);
4315   Node* young_card = __ ConI((jint)G1SATBCardTableModRefBS::g1_young_card_val());
4316   Node* dirty_card = __ ConI((jint)CardTableModRefBS::dirty_card_val());
4317   Node* zeroX = __ ConX(0);
4318 
4319   // Get the alias_index for raw card-mark memory
4320   const TypePtr* card_type = TypeRawPtr::BOTTOM;
4321 
4322   const TypeFunc *tf = OptoRuntime::g1_wb_post_Type();
4323 
4324   // Offsets into the thread
4325   const int index_offset  = in_bytes(JavaThread::dirty_card_queue_offset() +
4326                                      DirtyCardQueue::byte_offset_of_index());
4327   const int buffer_offset = in_bytes(JavaThread::dirty_card_queue_offset() +
4328                                      DirtyCardQueue::byte_offset_of_buf());
4329 
4330   // Pointers into the thread
4331 
4332   Node* buffer_adr = __ AddP(no_base, tls, __ ConX(buffer_offset));
4333   Node* index_adr =  __ AddP(no_base, tls, __ ConX(index_offset));
4334 
4335   // Now some values
4336   // Use ctrl to avoid hoisting these values past a safepoint, which could
4337   // potentially reset these fields in the JavaThread.
4338   Node* index  = __ load(__ ctrl(), index_adr, TypeX_X, TypeX_X->basic_type(), Compile::AliasIdxRaw);
4339   Node* buffer = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
4340 
4341   // Convert the store obj pointer to an int prior to doing math on it
4342   // Must use ctrl to prevent "integerized oop" existing across safepoint
4343   Node* cast =  __ CastPX(__ ctrl(), adr);
4344 
4345   // Divide pointer by card size
4346   Node* card_offset = __ URShiftX( cast, __ ConI(CardTableModRefBS::card_shift) );
4347 
4348   // Combine card table base and card offset
4349   Node* card_adr = __ AddP(no_base, byte_map_base_node(), card_offset );
4350 
4351   // If we know the value being stored does it cross regions?
4352 
4353   if (val != NULL) {
4354     // Does the store cause us to cross regions?
4355 
4356     // Should be able to do an unsigned compare of region_size instead of
4357     // and extra shift. Do we have an unsigned compare??
4358     // Node* region_size = __ ConI(1 << HeapRegion::LogOfHRGrainBytes);
4359     Node* xor_res =  __ URShiftX ( __ XorX( cast,  __ CastPX(__ ctrl(), val)), __ ConI(HeapRegion::LogOfHRGrainBytes));
4360 
4361     // if (xor_res == 0) same region so skip
4362     __ if_then(xor_res, BoolTest::ne, zeroX); {
4363 
4364       // No barrier if we are storing a NULL
4365       __ if_then(val, BoolTest::ne, null(), unlikely); {
4366 
4367         // Ok must mark the card if not already dirty
4368 
4369         // load the original value of the card
4370         Node* card_val = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
4371 
4372         __ if_then(card_val, BoolTest::ne, young_card); {
4373           sync_kit(ideal);
4374           // Use Op_MemBarVolatile to achieve the effect of a StoreLoad barrier.
4375           insert_mem_bar(Op_MemBarVolatile, oop_store);
4376           __ sync_kit(this);
4377 
4378           Node* card_val_reload = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
4379           __ if_then(card_val_reload, BoolTest::ne, dirty_card); {
4380             g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
4381           } __ end_if();
4382         } __ end_if();
4383       } __ end_if();
4384     } __ end_if();
4385   } else {
4386     // The Object.clone() intrinsic uses this path if !ReduceInitialCardMarks.
4387     // We don't need a barrier here if the destination is a newly allocated object
4388     // in Eden. Otherwise, GC verification breaks because we assume that cards in Eden
4389     // are set to 'g1_young_gen' (see G1SATBCardTableModRefBS::verify_g1_young_region()).
4390     assert(!use_ReduceInitialCardMarks(), "can only happen with card marking");
4391     Node* card_val = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
4392     __ if_then(card_val, BoolTest::ne, young_card); {
4393       g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
4394     } __ end_if();
4395   }
4396 
4397   // Final sync IdealKit and GraphKit.
4398   final_sync(ideal);
4399 }
4400 #undef __
4401 
4402 
4403 Node* GraphKit::load_String_length(Node* ctrl, Node* str) {
4404   Node* len = load_array_length(load_String_value(ctrl, str));
4405   Node* coder = load_String_coder(ctrl, str);
4406   // Divide length by 2 if coder is UTF16
4407   return _gvn.transform(new RShiftINode(len, coder));
4408 }
4409 
4410 Node* GraphKit::load_String_value(Node* ctrl, Node* str) {
4411   int value_offset = java_lang_String::value_offset_in_bytes();
4412   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4413                                                      false, NULL, Type::Offset(0));
4414   const TypePtr* value_field_type = string_type->add_offset(value_offset);
4415   const TypeAryPtr* value_type = TypeAryPtr::make(TypePtr::NotNull,
4416                                                   TypeAry::make(TypeInt::BYTE, TypeInt::POS),
4417                                                   ciTypeArrayKlass::make(T_BYTE), true, Type::Offset(0));
4418   int value_field_idx = C->get_alias_index(value_field_type);
4419   Node* load = make_load(ctrl, basic_plus_adr(str, str, value_offset),
4420                          value_type, T_OBJECT, value_field_idx, MemNode::unordered);
4421   // String.value field is known to be @Stable.
4422   if (UseImplicitStableValues) {
4423     load = cast_array_to_stable(load, value_type);
4424   }
4425   return load;
4426 }
4427 
4428 Node* GraphKit::load_String_coder(Node* ctrl, Node* str) {
4429   if (!CompactStrings) {
4430     return intcon(java_lang_String::CODER_UTF16);
4431   }
4432   int coder_offset = java_lang_String::coder_offset_in_bytes();
4433   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4434                                                      false, NULL, Type::Offset(0));
4435   const TypePtr* coder_field_type = string_type->add_offset(coder_offset);
4436   int coder_field_idx = C->get_alias_index(coder_field_type);
4437   return make_load(ctrl, basic_plus_adr(str, str, coder_offset),
4438                    TypeInt::BYTE, T_BYTE, coder_field_idx, MemNode::unordered);
4439 }
4440 
4441 void GraphKit::store_String_value(Node* ctrl, Node* str, Node* value) {
4442   int value_offset = java_lang_String::value_offset_in_bytes();
4443   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4444                                                      false, NULL, Type::Offset(0));
4445   const TypePtr* value_field_type = string_type->add_offset(value_offset);
4446   store_oop_to_object(ctrl, str,  basic_plus_adr(str, value_offset), value_field_type,
4447       value, TypeAryPtr::BYTES, T_OBJECT, MemNode::unordered);
4448 }
4449 
4450 void GraphKit::store_String_coder(Node* ctrl, Node* str, Node* value) {
4451   int coder_offset = java_lang_String::coder_offset_in_bytes();
4452   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4453                                                      false, NULL, Type::Offset(0));
4454   const TypePtr* coder_field_type = string_type->add_offset(coder_offset);
4455   int coder_field_idx = C->get_alias_index(coder_field_type);
4456   store_to_memory(ctrl, basic_plus_adr(str, coder_offset),
4457                   value, T_BYTE, coder_field_idx, MemNode::unordered);
4458 }
4459 
4460 // Capture src and dst memory state with a MergeMemNode
4461 Node* GraphKit::capture_memory(const TypePtr* src_type, const TypePtr* dst_type) {
4462   if (src_type == dst_type) {
4463     // Types are equal, we don't need a MergeMemNode
4464     return memory(src_type);
4465   }
4466   MergeMemNode* merge = MergeMemNode::make(map()->memory());
4467   record_for_igvn(merge); // fold it up later, if possible
4468   int src_idx = C->get_alias_index(src_type);
4469   int dst_idx = C->get_alias_index(dst_type);
4470   merge->set_memory_at(src_idx, memory(src_idx));
4471   merge->set_memory_at(dst_idx, memory(dst_idx));
4472   return merge;
4473 }
4474 
4475 Node* GraphKit::compress_string(Node* src, const TypeAryPtr* src_type, Node* dst, Node* count) {
4476   assert(Matcher::match_rule_supported(Op_StrCompressedCopy), "Intrinsic not supported");
4477   assert(src_type == TypeAryPtr::BYTES || src_type == TypeAryPtr::CHARS, "invalid source type");
4478   // If input and output memory types differ, capture both states to preserve
4479   // the dependency between preceding and subsequent loads/stores.
4480   // For example, the following program:
4481   //  StoreB
4482   //  compress_string
4483   //  LoadB
4484   // has this memory graph (use->def):
4485   //  LoadB -> compress_string -> CharMem
4486   //             ... -> StoreB -> ByteMem
4487   // The intrinsic hides the dependency between LoadB and StoreB, causing
4488   // the load to read from memory not containing the result of the StoreB.
4489   // The correct memory graph should look like this:
4490   //  LoadB -> compress_string -> MergeMem(CharMem, StoreB(ByteMem))
4491   Node* mem = capture_memory(src_type, TypeAryPtr::BYTES);
4492   StrCompressedCopyNode* str = new StrCompressedCopyNode(control(), mem, src, dst, count);
4493   Node* res_mem = _gvn.transform(new SCMemProjNode(str));
4494   set_memory(res_mem, TypeAryPtr::BYTES);
4495   return str;
4496 }
4497 
4498 void GraphKit::inflate_string(Node* src, Node* dst, const TypeAryPtr* dst_type, Node* count) {
4499   assert(Matcher::match_rule_supported(Op_StrInflatedCopy), "Intrinsic not supported");
4500   assert(dst_type == TypeAryPtr::BYTES || dst_type == TypeAryPtr::CHARS, "invalid dest type");
4501   // Capture src and dst memory (see comment in 'compress_string').
4502   Node* mem = capture_memory(TypeAryPtr::BYTES, dst_type);
4503   StrInflatedCopyNode* str = new StrInflatedCopyNode(control(), mem, src, dst, count);
4504   set_memory(_gvn.transform(str), dst_type);
4505 }
4506 
4507 void GraphKit::inflate_string_slow(Node* src, Node* dst, Node* start, Node* count) {
4508   /**
4509    * int i_char = start;
4510    * for (int i_byte = 0; i_byte < count; i_byte++) {
4511    *   dst[i_char++] = (char)(src[i_byte] & 0xff);
4512    * }
4513    */
4514   add_predicate();
4515   RegionNode* head = new RegionNode(3);
4516   head->init_req(1, control());
4517   gvn().set_type(head, Type::CONTROL);
4518   record_for_igvn(head);
4519 
4520   Node* i_byte = new PhiNode(head, TypeInt::INT);
4521   i_byte->init_req(1, intcon(0));
4522   gvn().set_type(i_byte, TypeInt::INT);
4523   record_for_igvn(i_byte);
4524 
4525   Node* i_char = new PhiNode(head, TypeInt::INT);
4526   i_char->init_req(1, start);
4527   gvn().set_type(i_char, TypeInt::INT);
4528   record_for_igvn(i_char);
4529 
4530   Node* mem = PhiNode::make(head, memory(TypeAryPtr::BYTES), Type::MEMORY, TypeAryPtr::BYTES);
4531   gvn().set_type(mem, Type::MEMORY);
4532   record_for_igvn(mem);
4533   set_control(head);
4534   set_memory(mem, TypeAryPtr::BYTES);
4535   Node* ch = load_array_element(control(), src, i_byte, TypeAryPtr::BYTES);
4536   Node* st = store_to_memory(control(), array_element_address(dst, i_char, T_BYTE),
4537                              AndI(ch, intcon(0xff)), T_CHAR, TypeAryPtr::BYTES, MemNode::unordered,
4538                              false, false, true /* mismatched */);
4539 
4540   IfNode* iff = create_and_map_if(head, Bool(CmpI(i_byte, count), BoolTest::lt), PROB_FAIR, COUNT_UNKNOWN);
4541   head->init_req(2, IfTrue(iff));
4542   mem->init_req(2, st);
4543   i_byte->init_req(2, AddI(i_byte, intcon(1)));
4544   i_char->init_req(2, AddI(i_char, intcon(2)));
4545 
4546   set_control(IfFalse(iff));
4547   set_memory(st, TypeAryPtr::BYTES);
4548 }
4549 
4550 Node* GraphKit::make_constant_from_field(ciField* field, Node* obj) {
4551   if (!field->is_constant()) {
4552     return NULL; // Field not marked as constant.
4553   }
4554   ciInstance* holder = NULL;
4555   if (!field->is_static()) {
4556     ciObject* const_oop = obj->bottom_type()->is_oopptr()->const_oop();
4557     if (const_oop != NULL && const_oop->is_instance()) {
4558       holder = const_oop->as_instance();
4559     }
4560   }
4561   const Type* con_type = Type::make_constant_from_field(field, holder, field->layout_type(),
4562                                                         /*is_unsigned_load=*/false);
4563   if (con_type != NULL) {
4564     Node* con = makecon(con_type);
4565     if (field->layout_type() == T_VALUETYPE) {
4566       // Load value type from constant oop
4567       con = ValueTypeNode::make(this, con);
4568     }
4569     return con;
4570   }
4571   return NULL;
4572 }
4573 
4574 Node* GraphKit::cast_array_to_stable(Node* ary, const TypeAryPtr* ary_type) {
4575   // Reify the property as a CastPP node in Ideal graph to comply with monotonicity
4576   // assumption of CCP analysis.
4577   return _gvn.transform(new CastPPNode(ary, ary_type->cast_to_stable(true)));
4578 }