1 /*
   2  * Copyright (c) 2001, 2012, 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 "gc_implementation/g1/g1SATBCardTableModRefBS.hpp"
  28 #include "gc_implementation/g1/heapRegion.hpp"
  29 #include "gc_interface/collectedHeap.hpp"
  30 #include "memory/barrierSet.hpp"
  31 #include "memory/cardTableModRefBS.hpp"
  32 #include "opto/addnode.hpp"
  33 #include "opto/graphKit.hpp"
  34 #include "opto/idealKit.hpp"
  35 #include "opto/locknode.hpp"
  36 #include "opto/machnode.hpp"
  37 #include "opto/parse.hpp"
  38 #include "opto/rootnode.hpp"
  39 #include "opto/runtime.hpp"
  40 #include "runtime/deoptimization.hpp"
  41 #include "runtime/sharedRuntime.hpp"
  42 
  43 //----------------------------GraphKit-----------------------------------------
  44 // Main utility constructor.
  45 GraphKit::GraphKit(JVMState* jvms)
  46   : Phase(Phase::Parser),
  47     _env(C->env()),
  48     _gvn(*C->initial_gvn())
  49 {
  50   _exceptions = jvms->map()->next_exception();
  51   if (_exceptions != NULL)  jvms->map()->set_next_exception(NULL);
  52   set_jvms(jvms);
  53 }
  54 
  55 // Private constructor for parser.
  56 GraphKit::GraphKit()
  57   : Phase(Phase::Parser),
  58     _env(C->env()),
  59     _gvn(*C->initial_gvn())
  60 {
  61   _exceptions = NULL;
  62   set_map(NULL);
  63   debug_only(_sp = -99);
  64   debug_only(set_bci(-99));
  65 }
  66 
  67 
  68 
  69 //---------------------------clean_stack---------------------------------------
  70 // Clear away rubbish from the stack area of the JVM state.
  71 // This destroys any arguments that may be waiting on the stack.
  72 void GraphKit::clean_stack(int from_sp) {
  73   SafePointNode* map      = this->map();
  74   JVMState*      jvms     = this->jvms();
  75   int            stk_size = jvms->stk_size();
  76   int            stkoff   = jvms->stkoff();
  77   Node*          top      = this->top();
  78   for (int i = from_sp; i < stk_size; i++) {
  79     if (map->in(stkoff + i) != top) {
  80       map->set_req(stkoff + i, top);
  81     }
  82   }
  83 }
  84 
  85 
  86 //--------------------------------sync_jvms-----------------------------------
  87 // Make sure our current jvms agrees with our parse state.
  88 JVMState* GraphKit::sync_jvms() const {
  89   JVMState* jvms = this->jvms();
  90   jvms->set_bci(bci());       // Record the new bci in the JVMState
  91   jvms->set_sp(sp());         // Record the new sp in the JVMState
  92   assert(jvms_in_sync(), "jvms is now in sync");
  93   return jvms;
  94 }
  95 
  96 //--------------------------------sync_jvms_for_reexecute---------------------
  97 // Make sure our current jvms agrees with our parse state.  This version
  98 // uses the reexecute_sp for reexecuting bytecodes.
  99 JVMState* GraphKit::sync_jvms_for_reexecute() {
 100   JVMState* jvms = this->jvms();
 101   jvms->set_bci(bci());          // Record the new bci in the JVMState
 102   jvms->set_sp(reexecute_sp());  // Record the new sp in the JVMState
 103   return jvms;
 104 }
 105 
 106 #ifdef ASSERT
 107 bool GraphKit::jvms_in_sync() const {
 108   Parse* parse = is_Parse();
 109   if (parse == NULL) {
 110     if (bci() !=      jvms()->bci())          return false;
 111     if (sp()  != (int)jvms()->sp())           return false;
 112     return true;
 113   }
 114   if (jvms()->method() != parse->method())    return false;
 115   if (jvms()->bci()    != parse->bci())       return false;
 116   int jvms_sp = jvms()->sp();
 117   if (jvms_sp          != parse->sp())        return false;
 118   int jvms_depth = jvms()->depth();
 119   if (jvms_depth       != parse->depth())     return false;
 120   return true;
 121 }
 122 
 123 // Local helper checks for special internal merge points
 124 // used to accumulate and merge exception states.
 125 // They are marked by the region's in(0) edge being the map itself.
 126 // Such merge points must never "escape" into the parser at large,
 127 // until they have been handed to gvn.transform.
 128 static bool is_hidden_merge(Node* reg) {
 129   if (reg == NULL)  return false;
 130   if (reg->is_Phi()) {
 131     reg = reg->in(0);
 132     if (reg == NULL)  return false;
 133   }
 134   return reg->is_Region() && reg->in(0) != NULL && reg->in(0)->is_Root();
 135 }
 136 
 137 void GraphKit::verify_map() const {
 138   if (map() == NULL)  return;  // null map is OK
 139   assert(map()->req() <= jvms()->endoff(), "no extra garbage on map");
 140   assert(!map()->has_exceptions(),    "call add_exception_states_from 1st");
 141   assert(!is_hidden_merge(control()), "call use_exception_state, not set_map");
 142 }
 143 
 144 void GraphKit::verify_exception_state(SafePointNode* ex_map) {
 145   assert(ex_map->next_exception() == NULL, "not already part of a chain");
 146   assert(has_saved_ex_oop(ex_map), "every exception state has an ex_oop");
 147 }
 148 #endif
 149 
 150 //---------------------------stop_and_kill_map---------------------------------
 151 // Set _map to NULL, signalling a stop to further bytecode execution.
 152 // First smash the current map's control to a constant, to mark it dead.
 153 void GraphKit::stop_and_kill_map() {
 154   SafePointNode* dead_map = stop();
 155   if (dead_map != NULL) {
 156     dead_map->disconnect_inputs(NULL, C); // Mark the map as killed.
 157     assert(dead_map->is_killed(), "must be so marked");
 158   }
 159 }
 160 
 161 
 162 //--------------------------------stopped--------------------------------------
 163 // Tell if _map is NULL, or control is top.
 164 bool GraphKit::stopped() {
 165   if (map() == NULL)           return true;
 166   else if (control() == top()) return true;
 167   else                         return false;
 168 }
 169 
 170 
 171 //-----------------------------has_ex_handler----------------------------------
 172 // Tell if this method or any caller method has exception handlers.
 173 bool GraphKit::has_ex_handler() {
 174   for (JVMState* jvmsp = jvms(); jvmsp != NULL; jvmsp = jvmsp->caller()) {
 175     if (jvmsp->has_method() && jvmsp->method()->has_exception_handlers()) {
 176       return true;
 177     }
 178   }
 179   return false;
 180 }
 181 
 182 //------------------------------save_ex_oop------------------------------------
 183 // Save an exception without blowing stack contents or other JVM state.
 184 void GraphKit::set_saved_ex_oop(SafePointNode* ex_map, Node* ex_oop) {
 185   assert(!has_saved_ex_oop(ex_map), "clear ex-oop before setting again");
 186   ex_map->add_req(ex_oop);
 187   debug_only(verify_exception_state(ex_map));
 188 }
 189 
 190 inline static Node* common_saved_ex_oop(SafePointNode* ex_map, bool clear_it) {
 191   assert(GraphKit::has_saved_ex_oop(ex_map), "ex_oop must be there");
 192   Node* ex_oop = ex_map->in(ex_map->req()-1);
 193   if (clear_it)  ex_map->del_req(ex_map->req()-1);
 194   return ex_oop;
 195 }
 196 
 197 //-----------------------------saved_ex_oop------------------------------------
 198 // Recover a saved exception from its map.
 199 Node* GraphKit::saved_ex_oop(SafePointNode* ex_map) {
 200   return common_saved_ex_oop(ex_map, false);
 201 }
 202 
 203 //--------------------------clear_saved_ex_oop---------------------------------
 204 // Erase a previously saved exception from its map.
 205 Node* GraphKit::clear_saved_ex_oop(SafePointNode* ex_map) {
 206   return common_saved_ex_oop(ex_map, true);
 207 }
 208 
 209 #ifdef ASSERT
 210 //---------------------------has_saved_ex_oop----------------------------------
 211 // Erase a previously saved exception from its map.
 212 bool GraphKit::has_saved_ex_oop(SafePointNode* ex_map) {
 213   return ex_map->req() == ex_map->jvms()->endoff()+1;
 214 }
 215 #endif
 216 
 217 //-------------------------make_exception_state--------------------------------
 218 // Turn the current JVM state into an exception state, appending the ex_oop.
 219 SafePointNode* GraphKit::make_exception_state(Node* ex_oop) {
 220   sync_jvms();
 221   SafePointNode* ex_map = stop();  // do not manipulate this map any more
 222   set_saved_ex_oop(ex_map, ex_oop);
 223   return ex_map;
 224 }
 225 
 226 
 227 //--------------------------add_exception_state--------------------------------
 228 // Add an exception to my list of exceptions.
 229 void GraphKit::add_exception_state(SafePointNode* ex_map) {
 230   if (ex_map == NULL || ex_map->control() == top()) {
 231     return;
 232   }
 233 #ifdef ASSERT
 234   verify_exception_state(ex_map);
 235   if (has_exceptions()) {
 236     assert(ex_map->jvms()->same_calls_as(_exceptions->jvms()), "all collected exceptions must come from the same place");
 237   }
 238 #endif
 239 
 240   // If there is already an exception of exactly this type, merge with it.
 241   // In particular, null-checks and other low-level exceptions common up here.
 242   Node*       ex_oop  = saved_ex_oop(ex_map);
 243   const Type* ex_type = _gvn.type(ex_oop);
 244   if (ex_oop == top()) {
 245     // No action needed.
 246     return;
 247   }
 248   assert(ex_type->isa_instptr(), "exception must be an instance");
 249   for (SafePointNode* e2 = _exceptions; e2 != NULL; e2 = e2->next_exception()) {
 250     const Type* ex_type2 = _gvn.type(saved_ex_oop(e2));
 251     // We check sp also because call bytecodes can generate exceptions
 252     // both before and after arguments are popped!
 253     if (ex_type2 == ex_type
 254         && e2->_jvms->sp() == ex_map->_jvms->sp()) {
 255       combine_exception_states(ex_map, e2);
 256       return;
 257     }
 258   }
 259 
 260   // No pre-existing exception of the same type.  Chain it on the list.
 261   push_exception_state(ex_map);
 262 }
 263 
 264 //-----------------------add_exception_states_from-----------------------------
 265 void GraphKit::add_exception_states_from(JVMState* jvms) {
 266   SafePointNode* ex_map = jvms->map()->next_exception();
 267   if (ex_map != NULL) {
 268     jvms->map()->set_next_exception(NULL);
 269     for (SafePointNode* next_map; ex_map != NULL; ex_map = next_map) {
 270       next_map = ex_map->next_exception();
 271       ex_map->set_next_exception(NULL);
 272       add_exception_state(ex_map);
 273     }
 274   }
 275 }
 276 
 277 //-----------------------transfer_exceptions_into_jvms-------------------------
 278 JVMState* GraphKit::transfer_exceptions_into_jvms() {
 279   if (map() == NULL) {
 280     // We need a JVMS to carry the exceptions, but the map has gone away.
 281     // Create a scratch JVMS, cloned from any of the exception states...
 282     if (has_exceptions()) {
 283       _map = _exceptions;
 284       _map = clone_map();
 285       _map->set_next_exception(NULL);
 286       clear_saved_ex_oop(_map);
 287       debug_only(verify_map());
 288     } else {
 289       // ...or created from scratch
 290       JVMState* jvms = new (C) JVMState(_method, NULL);
 291       jvms->set_bci(_bci);
 292       jvms->set_sp(_sp);
 293       jvms->set_map(new (C) SafePointNode(TypeFunc::Parms, jvms));
 294       set_jvms(jvms);
 295       for (uint i = 0; i < map()->req(); i++)  map()->init_req(i, top());
 296       set_all_memory(top());
 297       while (map()->req() < jvms->endoff())  map()->add_req(top());
 298     }
 299     // (This is a kludge, in case you didn't notice.)
 300     set_control(top());
 301   }
 302   JVMState* jvms = sync_jvms();
 303   assert(!jvms->map()->has_exceptions(), "no exceptions on this map yet");
 304   jvms->map()->set_next_exception(_exceptions);
 305   _exceptions = NULL;   // done with this set of exceptions
 306   return jvms;
 307 }
 308 
 309 static inline void add_n_reqs(Node* dstphi, Node* srcphi) {
 310   assert(is_hidden_merge(dstphi), "must be a special merge node");
 311   assert(is_hidden_merge(srcphi), "must be a special merge node");
 312   uint limit = srcphi->req();
 313   for (uint i = PhiNode::Input; i < limit; i++) {
 314     dstphi->add_req(srcphi->in(i));
 315   }
 316 }
 317 static inline void add_one_req(Node* dstphi, Node* src) {
 318   assert(is_hidden_merge(dstphi), "must be a special merge node");
 319   assert(!is_hidden_merge(src), "must not be a special merge node");
 320   dstphi->add_req(src);
 321 }
 322 
 323 //-----------------------combine_exception_states------------------------------
 324 // This helper function combines exception states by building phis on a
 325 // specially marked state-merging region.  These regions and phis are
 326 // untransformed, and can build up gradually.  The region is marked by
 327 // having a control input of its exception map, rather than NULL.  Such
 328 // regions do not appear except in this function, and in use_exception_state.
 329 void GraphKit::combine_exception_states(SafePointNode* ex_map, SafePointNode* phi_map) {
 330   if (failing())  return;  // dying anyway...
 331   JVMState* ex_jvms = ex_map->_jvms;
 332   assert(ex_jvms->same_calls_as(phi_map->_jvms), "consistent call chains");
 333   assert(ex_jvms->stkoff() == phi_map->_jvms->stkoff(), "matching locals");
 334   assert(ex_jvms->sp() == phi_map->_jvms->sp(), "matching stack sizes");
 335   assert(ex_jvms->monoff() == phi_map->_jvms->monoff(), "matching JVMS");
 336   assert(ex_map->req() == phi_map->req(), "matching maps");
 337   uint tos = ex_jvms->stkoff() + ex_jvms->sp();
 338   Node*         hidden_merge_mark = root();
 339   Node*         region  = phi_map->control();
 340   MergeMemNode* phi_mem = phi_map->merged_memory();
 341   MergeMemNode* ex_mem  = ex_map->merged_memory();
 342   if (region->in(0) != hidden_merge_mark) {
 343     // The control input is not (yet) a specially-marked region in phi_map.
 344     // Make it so, and build some phis.
 345     region = new (C) RegionNode(2);
 346     _gvn.set_type(region, Type::CONTROL);
 347     region->set_req(0, hidden_merge_mark);  // marks an internal ex-state
 348     region->init_req(1, phi_map->control());
 349     phi_map->set_control(region);
 350     Node* io_phi = PhiNode::make(region, phi_map->i_o(), Type::ABIO);
 351     record_for_igvn(io_phi);
 352     _gvn.set_type(io_phi, Type::ABIO);
 353     phi_map->set_i_o(io_phi);
 354     for (MergeMemStream mms(phi_mem); mms.next_non_empty(); ) {
 355       Node* m = mms.memory();
 356       Node* m_phi = PhiNode::make(region, m, Type::MEMORY, mms.adr_type(C));
 357       record_for_igvn(m_phi);
 358       _gvn.set_type(m_phi, Type::MEMORY);
 359       mms.set_memory(m_phi);
 360     }
 361   }
 362 
 363   // Either or both of phi_map and ex_map might already be converted into phis.
 364   Node* ex_control = ex_map->control();
 365   // if there is special marking on ex_map also, we add multiple edges from src
 366   bool add_multiple = (ex_control->in(0) == hidden_merge_mark);
 367   // how wide was the destination phi_map, originally?
 368   uint orig_width = region->req();
 369 
 370   if (add_multiple) {
 371     add_n_reqs(region, ex_control);
 372     add_n_reqs(phi_map->i_o(), ex_map->i_o());
 373   } else {
 374     // ex_map has no merges, so we just add single edges everywhere
 375     add_one_req(region, ex_control);
 376     add_one_req(phi_map->i_o(), ex_map->i_o());
 377   }
 378   for (MergeMemStream mms(phi_mem, ex_mem); mms.next_non_empty2(); ) {
 379     if (mms.is_empty()) {
 380       // get a copy of the base memory, and patch some inputs into it
 381       const TypePtr* adr_type = mms.adr_type(C);
 382       Node* phi = mms.force_memory()->as_Phi()->slice_memory(adr_type);
 383       assert(phi->as_Phi()->region() == mms.base_memory()->in(0), "");
 384       mms.set_memory(phi);
 385       // Prepare to append interesting stuff onto the newly sliced phi:
 386       while (phi->req() > orig_width)  phi->del_req(phi->req()-1);
 387     }
 388     // Append stuff from ex_map:
 389     if (add_multiple) {
 390       add_n_reqs(mms.memory(), mms.memory2());
 391     } else {
 392       add_one_req(mms.memory(), mms.memory2());
 393     }
 394   }
 395   uint limit = ex_map->req();
 396   for (uint i = TypeFunc::Parms; i < limit; i++) {
 397     // Skip everything in the JVMS after tos.  (The ex_oop follows.)
 398     if (i == tos)  i = ex_jvms->monoff();
 399     Node* src = ex_map->in(i);
 400     Node* dst = phi_map->in(i);
 401     if (src != dst) {
 402       PhiNode* phi;
 403       if (dst->in(0) != region) {
 404         dst = phi = PhiNode::make(region, dst, _gvn.type(dst));
 405         record_for_igvn(phi);
 406         _gvn.set_type(phi, phi->type());
 407         phi_map->set_req(i, dst);
 408         // Prepare to append interesting stuff onto the new phi:
 409         while (dst->req() > orig_width)  dst->del_req(dst->req()-1);
 410       } else {
 411         assert(dst->is_Phi(), "nobody else uses a hidden region");
 412         phi = (PhiNode*)dst;
 413       }
 414       if (add_multiple && src->in(0) == ex_control) {
 415         // Both are phis.
 416         add_n_reqs(dst, src);
 417       } else {
 418         while (dst->req() < region->req())  add_one_req(dst, src);
 419       }
 420       const Type* srctype = _gvn.type(src);
 421       if (phi->type() != srctype) {
 422         const Type* dsttype = phi->type()->meet(srctype);
 423         if (phi->type() != dsttype) {
 424           phi->set_type(dsttype);
 425           _gvn.set_type(phi, dsttype);
 426         }
 427       }
 428     }
 429   }
 430 }
 431 
 432 //--------------------------use_exception_state--------------------------------
 433 Node* GraphKit::use_exception_state(SafePointNode* phi_map) {
 434   if (failing()) { stop(); return top(); }
 435   Node* region = phi_map->control();
 436   Node* hidden_merge_mark = root();
 437   assert(phi_map->jvms()->map() == phi_map, "sanity: 1-1 relation");
 438   Node* ex_oop = clear_saved_ex_oop(phi_map);
 439   if (region->in(0) == hidden_merge_mark) {
 440     // Special marking for internal ex-states.  Process the phis now.
 441     region->set_req(0, region);  // now it's an ordinary region
 442     set_jvms(phi_map->jvms());   // ...so now we can use it as a map
 443     // Note: Setting the jvms also sets the bci and sp.
 444     set_control(_gvn.transform(region));
 445     uint tos = jvms()->stkoff() + sp();
 446     for (uint i = 1; i < tos; i++) {
 447       Node* x = phi_map->in(i);
 448       if (x->in(0) == region) {
 449         assert(x->is_Phi(), "expected a special phi");
 450         phi_map->set_req(i, _gvn.transform(x));
 451       }
 452     }
 453     for (MergeMemStream mms(merged_memory()); mms.next_non_empty(); ) {
 454       Node* x = mms.memory();
 455       if (x->in(0) == region) {
 456         assert(x->is_Phi(), "nobody else uses a hidden region");
 457         mms.set_memory(_gvn.transform(x));
 458       }
 459     }
 460     if (ex_oop->in(0) == region) {
 461       assert(ex_oop->is_Phi(), "expected a special phi");
 462       ex_oop = _gvn.transform(ex_oop);
 463     }
 464   } else {
 465     set_jvms(phi_map->jvms());
 466   }
 467 
 468   assert(!is_hidden_merge(phi_map->control()), "hidden ex. states cleared");
 469   assert(!is_hidden_merge(phi_map->i_o()), "hidden ex. states cleared");
 470   return ex_oop;
 471 }
 472 
 473 //---------------------------------java_bc-------------------------------------
 474 Bytecodes::Code GraphKit::java_bc() const {
 475   ciMethod* method = this->method();
 476   int       bci    = this->bci();
 477   if (method != NULL && bci != InvocationEntryBci)
 478     return method->java_code_at_bci(bci);
 479   else
 480     return Bytecodes::_illegal;
 481 }
 482 
 483 void GraphKit::uncommon_trap_if_should_post_on_exceptions(Deoptimization::DeoptReason reason,
 484                                                           bool must_throw) {
 485     // if the exception capability is set, then we will generate code
 486     // to check the JavaThread.should_post_on_exceptions flag to see
 487     // if we actually need to report exception events (for this
 488     // thread).  If we don't need to report exception events, we will
 489     // take the normal fast path provided by add_exception_events.  If
 490     // exception event reporting is enabled for this thread, we will
 491     // take the uncommon_trap in the BuildCutout below.
 492 
 493     // first must access the should_post_on_exceptions_flag in this thread's JavaThread
 494     Node* jthread = _gvn.transform(new (C) ThreadLocalNode());
 495     Node* adr = basic_plus_adr(top(), jthread, in_bytes(JavaThread::should_post_on_exceptions_flag_offset()));
 496     Node* should_post_flag = make_load(control(), adr, TypeInt::INT, T_INT, Compile::AliasIdxRaw, false);
 497 
 498     // Test the should_post_on_exceptions_flag vs. 0
 499     Node* chk = _gvn.transform( new (C) CmpINode(should_post_flag, intcon(0)) );
 500     Node* tst = _gvn.transform( new (C) BoolNode(chk, BoolTest::eq) );
 501 
 502     // Branch to slow_path if should_post_on_exceptions_flag was true
 503     { BuildCutout unless(this, tst, PROB_MAX);
 504       // Do not try anything fancy if we're notifying the VM on every throw.
 505       // Cf. case Bytecodes::_athrow in parse2.cpp.
 506       uncommon_trap(reason, Deoptimization::Action_none,
 507                     (ciKlass*)NULL, (char*)NULL, must_throw);
 508     }
 509 
 510 }
 511 
 512 //------------------------------builtin_throw----------------------------------
 513 void GraphKit::builtin_throw(Deoptimization::DeoptReason reason, Node* arg) {
 514   bool must_throw = true;
 515 
 516   if (env()->jvmti_can_post_on_exceptions()) {
 517     // check if we must post exception events, take uncommon trap if so
 518     uncommon_trap_if_should_post_on_exceptions(reason, must_throw);
 519     // here if should_post_on_exceptions is false
 520     // continue on with the normal codegen
 521   }
 522 
 523   // If this particular condition has not yet happened at this
 524   // bytecode, then use the uncommon trap mechanism, and allow for
 525   // a future recompilation if several traps occur here.
 526   // If the throw is hot, try to use a more complicated inline mechanism
 527   // which keeps execution inside the compiled code.
 528   bool treat_throw_as_hot = false;
 529   ciMethodData* md = method()->method_data();
 530 
 531   if (ProfileTraps) {
 532     if (too_many_traps(reason)) {
 533       treat_throw_as_hot = true;
 534     }
 535     // (If there is no MDO at all, assume it is early in
 536     // execution, and that any deopts are part of the
 537     // startup transient, and don't need to be remembered.)
 538 
 539     // Also, if there is a local exception handler, treat all throws
 540     // as hot if there has been at least one in this method.
 541     if (C->trap_count(reason) != 0
 542         && method()->method_data()->trap_count(reason) != 0
 543         && has_ex_handler()) {
 544         treat_throw_as_hot = true;
 545     }
 546   }
 547 
 548   // If this throw happens frequently, an uncommon trap might cause
 549   // a performance pothole.  If there is a local exception handler,
 550   // and if this particular bytecode appears to be deoptimizing often,
 551   // let us handle the throw inline, with a preconstructed instance.
 552   // Note:   If the deopt count has blown up, the uncommon trap
 553   // runtime is going to flush this nmethod, not matter what.
 554   if (treat_throw_as_hot
 555       && (!StackTraceInThrowable || OmitStackTraceInFastThrow)) {
 556     // If the throw is local, we use a pre-existing instance and
 557     // punt on the backtrace.  This would lead to a missing backtrace
 558     // (a repeat of 4292742) if the backtrace object is ever asked
 559     // for its backtrace.
 560     // Fixing this remaining case of 4292742 requires some flavor of
 561     // escape analysis.  Leave that for the future.
 562     ciInstance* ex_obj = NULL;
 563     switch (reason) {
 564     case Deoptimization::Reason_null_check:
 565       ex_obj = env()->NullPointerException_instance();
 566       break;
 567     case Deoptimization::Reason_div0_check:
 568       ex_obj = env()->ArithmeticException_instance();
 569       break;
 570     case Deoptimization::Reason_range_check:
 571       ex_obj = env()->ArrayIndexOutOfBoundsException_instance();
 572       break;
 573     case Deoptimization::Reason_class_check:
 574       if (java_bc() == Bytecodes::_aastore) {
 575         ex_obj = env()->ArrayStoreException_instance();
 576       } else {
 577         ex_obj = env()->ClassCastException_instance();
 578       }
 579       break;
 580     }
 581     if (failing()) { stop(); return; }  // exception allocation might fail
 582     if (ex_obj != NULL) {
 583       // Cheat with a preallocated exception object.
 584       if (C->log() != NULL)
 585         C->log()->elem("hot_throw preallocated='1' reason='%s'",
 586                        Deoptimization::trap_reason_name(reason));
 587       const TypeInstPtr* ex_con  = TypeInstPtr::make(ex_obj);
 588       Node*              ex_node = _gvn.transform( ConNode::make(C, ex_con) );
 589 
 590       // Clear the detail message of the preallocated exception object.
 591       // Weblogic sometimes mutates the detail message of exceptions
 592       // using reflection.
 593       int offset = java_lang_Throwable::get_detailMessage_offset();
 594       const TypePtr* adr_typ = ex_con->add_offset(offset);
 595 
 596       Node *adr = basic_plus_adr(ex_node, ex_node, offset);
 597       const TypeOopPtr* val_type = TypeOopPtr::make_from_klass(env()->String_klass());
 598       Node *store = store_oop_to_object(control(), ex_node, adr, adr_typ, null(), val_type, T_OBJECT);
 599 
 600       add_exception_state(make_exception_state(ex_node));
 601       return;
 602     }
 603   }
 604 
 605   // %%% Maybe add entry to OptoRuntime which directly throws the exc.?
 606   // It won't be much cheaper than bailing to the interp., since we'll
 607   // have to pass up all the debug-info, and the runtime will have to
 608   // create the stack trace.
 609 
 610   // Usual case:  Bail to interpreter.
 611   // Reserve the right to recompile if we haven't seen anything yet.
 612 
 613   Deoptimization::DeoptAction action = Deoptimization::Action_maybe_recompile;
 614   if (treat_throw_as_hot
 615       && (method()->method_data()->trap_recompiled_at(bci())
 616           || C->too_many_traps(reason))) {
 617     // We cannot afford to take more traps here.  Suffer in the interpreter.
 618     if (C->log() != NULL)
 619       C->log()->elem("hot_throw preallocated='0' reason='%s' mcount='%d'",
 620                      Deoptimization::trap_reason_name(reason),
 621                      C->trap_count(reason));
 622     action = Deoptimization::Action_none;
 623   }
 624 
 625   // "must_throw" prunes the JVM state to include only the stack, if there
 626   // are no local exception handlers.  This should cut down on register
 627   // allocation time and code size, by drastically reducing the number
 628   // of in-edges on the call to the uncommon trap.
 629 
 630   uncommon_trap(reason, action, (ciKlass*)NULL, (char*)NULL, must_throw);
 631 }
 632 
 633 
 634 //----------------------------PreserveJVMState---------------------------------
 635 PreserveJVMState::PreserveJVMState(GraphKit* kit, bool clone_map) {
 636   debug_only(kit->verify_map());
 637   _kit    = kit;
 638   _map    = kit->map();   // preserve the map
 639   _sp     = kit->sp();
 640   kit->set_map(clone_map ? kit->clone_map() : NULL);
 641 #ifdef ASSERT
 642   _bci    = kit->bci();
 643   Parse* parser = kit->is_Parse();
 644   int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo();
 645   _block  = block;
 646 #endif
 647 }
 648 PreserveJVMState::~PreserveJVMState() {
 649   GraphKit* kit = _kit;
 650 #ifdef ASSERT
 651   assert(kit->bci() == _bci, "bci must not shift");
 652   Parse* parser = kit->is_Parse();
 653   int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo();
 654   assert(block == _block,    "block must not shift");
 655 #endif
 656   kit->set_map(_map);
 657   kit->set_sp(_sp);
 658 }
 659 
 660 
 661 //-----------------------------BuildCutout-------------------------------------
 662 BuildCutout::BuildCutout(GraphKit* kit, Node* p, float prob, float cnt)
 663   : PreserveJVMState(kit)
 664 {
 665   assert(p->is_Con() || p->is_Bool(), "test must be a bool");
 666   SafePointNode* outer_map = _map;   // preserved map is caller's
 667   SafePointNode* inner_map = kit->map();
 668   IfNode* iff = kit->create_and_map_if(outer_map->control(), p, prob, cnt);
 669   outer_map->set_control(kit->gvn().transform( new (kit->C) IfTrueNode(iff) ));
 670   inner_map->set_control(kit->gvn().transform( new (kit->C) IfFalseNode(iff) ));
 671 }
 672 BuildCutout::~BuildCutout() {
 673   GraphKit* kit = _kit;
 674   assert(kit->stopped(), "cutout code must stop, throw, return, etc.");
 675 }
 676 
 677 //---------------------------PreserveReexecuteState----------------------------
 678 PreserveReexecuteState::PreserveReexecuteState(GraphKit* kit) {
 679   assert(!kit->stopped(), "must call stopped() before");
 680   _kit    =    kit;
 681   _sp     =    kit->sp();
 682   _reexecute = kit->jvms()->_reexecute;
 683 }
 684 PreserveReexecuteState::~PreserveReexecuteState() {
 685   if (_kit->stopped()) return;
 686   _kit->jvms()->_reexecute = _reexecute;
 687   _kit->set_sp(_sp);
 688 }
 689 
 690 //------------------------------clone_map--------------------------------------
 691 // Implementation of PreserveJVMState
 692 //
 693 // Only clone_map(...) here. If this function is only used in the
 694 // PreserveJVMState class we may want to get rid of this extra
 695 // function eventually and do it all there.
 696 
 697 SafePointNode* GraphKit::clone_map() {
 698   if (map() == NULL)  return NULL;
 699 
 700   // Clone the memory edge first
 701   Node* mem = MergeMemNode::make(C, map()->memory());
 702   gvn().set_type_bottom(mem);
 703 
 704   SafePointNode *clonemap = (SafePointNode*)map()->clone();
 705   JVMState* jvms = this->jvms();
 706   JVMState* clonejvms = jvms->clone_shallow(C);
 707   clonemap->set_memory(mem);
 708   clonemap->set_jvms(clonejvms);
 709   clonejvms->set_map(clonemap);
 710   record_for_igvn(clonemap);
 711   gvn().set_type_bottom(clonemap);
 712   return clonemap;
 713 }
 714 
 715 
 716 //-----------------------------set_map_clone-----------------------------------
 717 void GraphKit::set_map_clone(SafePointNode* m) {
 718   _map = m;
 719   _map = clone_map();
 720   _map->set_next_exception(NULL);
 721   debug_only(verify_map());
 722 }
 723 
 724 
 725 //----------------------------kill_dead_locals---------------------------------
 726 // Detect any locals which are known to be dead, and force them to top.
 727 void GraphKit::kill_dead_locals() {
 728   // Consult the liveness information for the locals.  If any
 729   // of them are unused, then they can be replaced by top().  This
 730   // should help register allocation time and cut down on the size
 731   // of the deoptimization information.
 732 
 733   // This call is made from many of the bytecode handling
 734   // subroutines called from the Big Switch in do_one_bytecode.
 735   // Every bytecode which might include a slow path is responsible
 736   // for killing its dead locals.  The more consistent we
 737   // are about killing deads, the fewer useless phis will be
 738   // constructed for them at various merge points.
 739 
 740   // bci can be -1 (InvocationEntryBci).  We return the entry
 741   // liveness for the method.
 742 
 743   if (method() == NULL || method()->code_size() == 0) {
 744     // We are building a graph for a call to a native method.
 745     // All locals are live.
 746     return;
 747   }
 748 
 749   ResourceMark rm;
 750 
 751   // Consult the liveness information for the locals.  If any
 752   // of them are unused, then they can be replaced by top().  This
 753   // should help register allocation time and cut down on the size
 754   // of the deoptimization information.
 755   MethodLivenessResult live_locals = method()->liveness_at_bci(bci());
 756 
 757   int len = (int)live_locals.size();
 758   assert(len <= jvms()->loc_size(), "too many live locals");
 759   for (int local = 0; local < len; local++) {
 760     if (!live_locals.at(local)) {
 761       set_local(local, top());
 762     }
 763   }
 764 }
 765 
 766 #ifdef ASSERT
 767 //-------------------------dead_locals_are_killed------------------------------
 768 // Return true if all dead locals are set to top in the map.
 769 // Used to assert "clean" debug info at various points.
 770 bool GraphKit::dead_locals_are_killed() {
 771   if (method() == NULL || method()->code_size() == 0) {
 772     // No locals need to be dead, so all is as it should be.
 773     return true;
 774   }
 775 
 776   // Make sure somebody called kill_dead_locals upstream.
 777   ResourceMark rm;
 778   for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) {
 779     if (jvms->loc_size() == 0)  continue;  // no locals to consult
 780     SafePointNode* map = jvms->map();
 781     ciMethod* method = jvms->method();
 782     int       bci    = jvms->bci();
 783     if (jvms == this->jvms()) {
 784       bci = this->bci();  // it might not yet be synched
 785     }
 786     MethodLivenessResult live_locals = method->liveness_at_bci(bci);
 787     int len = (int)live_locals.size();
 788     if (!live_locals.is_valid() || len == 0)
 789       // This method is trivial, or is poisoned by a breakpoint.
 790       return true;
 791     assert(len == jvms->loc_size(), "live map consistent with locals map");
 792     for (int local = 0; local < len; local++) {
 793       if (!live_locals.at(local) && map->local(jvms, local) != top()) {
 794         if (PrintMiscellaneous && (Verbose || WizardMode)) {
 795           tty->print_cr("Zombie local %d: ", local);
 796           jvms->dump();
 797         }
 798         return false;
 799       }
 800     }
 801   }
 802   return true;
 803 }
 804 
 805 #endif //ASSERT
 806 
 807 // Helper function for enforcing certain bytecodes to reexecute if
 808 // deoptimization happens
 809 static bool should_reexecute_implied_by_bytecode(JVMState *jvms, bool is_anewarray) {
 810   ciMethod* cur_method = jvms->method();
 811   int       cur_bci   = jvms->bci();
 812   if (cur_method != NULL && cur_bci != InvocationEntryBci) {
 813     Bytecodes::Code code = cur_method->java_code_at_bci(cur_bci);
 814     return Interpreter::bytecode_should_reexecute(code) ||
 815            is_anewarray && code == Bytecodes::_multianewarray;
 816     // Reexecute _multianewarray bytecode which was replaced with
 817     // sequence of [a]newarray. See Parse::do_multianewarray().
 818     //
 819     // Note: interpreter should not have it set since this optimization
 820     // is limited by dimensions and guarded by flag so in some cases
 821     // multianewarray() runtime calls will be generated and
 822     // the bytecode should not be reexecutes (stack will not be reset).
 823   } else
 824     return false;
 825 }
 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()->jvmti_can_access_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   // do not scribble on the input jvms
 871   JVMState* out_jvms = youngest_jvms->clone_deep(C);
 872   call->set_jvms(out_jvms); // Start jvms list for call node
 873 
 874   // For a known set of bytecodes, the interpreter should reexecute them if
 875   // deoptimization happens. We set the reexecute state for them here
 876   if (out_jvms->is_reexecute_undefined() && //don't change if already specified
 877       should_reexecute_implied_by_bytecode(out_jvms, call->is_AllocateArray())) {
 878     out_jvms->set_should_reexecute(true); //NOTE: youngest_jvms not changed
 879   }
 880 
 881   // Presize the call:
 882   DEBUG_ONLY(uint non_debug_edges = call->req());
 883   call->add_req_batch(top(), youngest_jvms->debug_depth());
 884   assert(call->req() == non_debug_edges + youngest_jvms->debug_depth(), "");
 885 
 886   // Set up edges so that the call looks like this:
 887   //  Call [state:] ctl io mem fptr retadr
 888   //       [parms:] parm0 ... parmN
 889   //       [root:]  loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN
 890   //    [...mid:]   loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN [...]
 891   //       [young:] loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN
 892   // Note that caller debug info precedes callee debug info.
 893 
 894   // Fill pointer walks backwards from "young:" to "root:" in the diagram above:
 895   uint debug_ptr = call->req();
 896 
 897   // Loop over the map input edges associated with jvms, add them
 898   // to the call node, & reset all offsets to match call node array.
 899   for (JVMState* in_jvms = youngest_jvms; in_jvms != NULL; ) {
 900     uint debug_end   = debug_ptr;
 901     uint debug_start = debug_ptr - in_jvms->debug_size();
 902     debug_ptr = debug_start;  // back up the ptr
 903 
 904     uint p = debug_start;  // walks forward in [debug_start, debug_end)
 905     uint j, k, l;
 906     SafePointNode* in_map = in_jvms->map();
 907     out_jvms->set_map(call);
 908 
 909     if (can_prune_locals) {
 910       assert(in_jvms->method() == out_jvms->method(), "sanity");
 911       // If the current throw can reach an exception handler in this JVMS,
 912       // then we must keep everything live that can reach that handler.
 913       // As a quick and dirty approximation, we look for any handlers at all.
 914       if (in_jvms->method()->has_exception_handlers()) {
 915         can_prune_locals = false;
 916       }
 917     }
 918 
 919     // Add the Locals
 920     k = in_jvms->locoff();
 921     l = in_jvms->loc_size();
 922     out_jvms->set_locoff(p);
 923     if (!can_prune_locals) {
 924       for (j = 0; j < l; j++)
 925         call->set_req(p++, in_map->in(k+j));
 926     } else {
 927       p += l;  // already set to top above by add_req_batch
 928     }
 929 
 930     // Add the Expression Stack
 931     k = in_jvms->stkoff();
 932     l = in_jvms->sp();
 933     out_jvms->set_stkoff(p);
 934     if (!can_prune_locals) {
 935       for (j = 0; j < l; j++)
 936         call->set_req(p++, in_map->in(k+j));
 937     } else if (can_prune_locals && stack_slots_not_pruned != 0) {
 938       // Divide stack into {S0,...,S1}, where S0 is set to top.
 939       uint s1 = stack_slots_not_pruned;
 940       stack_slots_not_pruned = 0;  // for next iteration
 941       if (s1 > l)  s1 = l;
 942       uint s0 = l - s1;
 943       p += s0;  // skip the tops preinstalled by add_req_batch
 944       for (j = s0; j < l; j++)
 945         call->set_req(p++, in_map->in(k+j));
 946     } else {
 947       p += l;  // already set to top above by add_req_batch
 948     }
 949 
 950     // Add the Monitors
 951     k = in_jvms->monoff();
 952     l = in_jvms->mon_size();
 953     out_jvms->set_monoff(p);
 954     for (j = 0; j < l; j++)
 955       call->set_req(p++, in_map->in(k+j));
 956 
 957     // Copy any scalar object fields.
 958     k = in_jvms->scloff();
 959     l = in_jvms->scl_size();
 960     out_jvms->set_scloff(p);
 961     for (j = 0; j < l; j++)
 962       call->set_req(p++, in_map->in(k+j));
 963 
 964     // Finish the new jvms.
 965     out_jvms->set_endoff(p);
 966 
 967     assert(out_jvms->endoff()     == debug_end,             "fill ptr must match");
 968     assert(out_jvms->depth()      == in_jvms->depth(),      "depth must match");
 969     assert(out_jvms->loc_size()   == in_jvms->loc_size(),   "size must match");
 970     assert(out_jvms->mon_size()   == in_jvms->mon_size(),   "size must match");
 971     assert(out_jvms->scl_size()   == in_jvms->scl_size(),   "size must match");
 972     assert(out_jvms->debug_size() == in_jvms->debug_size(), "size must match");
 973 
 974     // Update the two tail pointers in parallel.
 975     out_jvms = out_jvms->caller();
 976     in_jvms  = in_jvms->caller();
 977   }
 978 
 979   assert(debug_ptr == non_debug_edges, "debug info must fit exactly");
 980 
 981   // Test the correctness of JVMState::debug_xxx accessors:
 982   assert(call->jvms()->debug_start() == non_debug_edges, "");
 983   assert(call->jvms()->debug_end()   == call->req(), "");
 984   assert(call->jvms()->debug_depth() == call->req() - non_debug_edges, "");
 985 }
 986 
 987 bool GraphKit::compute_stack_effects(int& inputs, int& depth) {
 988   Bytecodes::Code code = java_bc();
 989   if (code == Bytecodes::_wide) {
 990     code = method()->java_code_at_bci(bci() + 1);
 991   }
 992 
 993   BasicType rtype = T_ILLEGAL;
 994   int       rsize = 0;
 995 
 996   if (code != Bytecodes::_illegal) {
 997     depth = Bytecodes::depth(code); // checkcast=0, athrow=-1
 998     rtype = Bytecodes::result_type(code); // checkcast=P, athrow=V
 999     if (rtype < T_CONFLICT)
1000       rsize = type2size[rtype];
1001   }
1002 
1003   switch (code) {
1004   case Bytecodes::_illegal:
1005     return false;
1006 
1007   case Bytecodes::_ldc:
1008   case Bytecodes::_ldc_w:
1009   case Bytecodes::_ldc2_w:
1010     inputs = 0;
1011     break;
1012 
1013   case Bytecodes::_dup:         inputs = 1;  break;
1014   case Bytecodes::_dup_x1:      inputs = 2;  break;
1015   case Bytecodes::_dup_x2:      inputs = 3;  break;
1016   case Bytecodes::_dup2:        inputs = 2;  break;
1017   case Bytecodes::_dup2_x1:     inputs = 3;  break;
1018   case Bytecodes::_dup2_x2:     inputs = 4;  break;
1019   case Bytecodes::_swap:        inputs = 2;  break;
1020   case Bytecodes::_arraylength: inputs = 1;  break;
1021 
1022   case Bytecodes::_getstatic:
1023   case Bytecodes::_putstatic:
1024   case Bytecodes::_getfield:
1025   case Bytecodes::_putfield:
1026     {
1027       bool ignored_will_link;
1028       ciField* field = method()->get_field_at_bci(bci(), ignored_will_link);
1029       int      size  = field->type()->size();
1030       bool is_get = (depth >= 0), is_static = (depth & 1);
1031       inputs = (is_static ? 0 : 1);
1032       if (is_get) {
1033         depth = size - inputs;
1034       } else {
1035         inputs += size;        // putxxx pops the value from the stack
1036         depth = - inputs;
1037       }
1038     }
1039     break;
1040 
1041   case Bytecodes::_invokevirtual:
1042   case Bytecodes::_invokespecial:
1043   case Bytecodes::_invokestatic:
1044   case Bytecodes::_invokedynamic:
1045   case Bytecodes::_invokeinterface:
1046     {
1047       bool ignored_will_link;
1048       ciSignature* declared_signature = NULL;
1049       ciMethod* ignored_callee = method()->get_method_at_bci(bci(), ignored_will_link, &declared_signature);
1050       assert(declared_signature != NULL, "cannot be null");
1051       inputs   = declared_signature->arg_size_for_bc(code);
1052       int size = declared_signature->return_type()->size();
1053       depth = size - inputs;
1054     }
1055     break;
1056 
1057   case Bytecodes::_multianewarray:
1058     {
1059       ciBytecodeStream iter(method());
1060       iter.reset_to_bci(bci());
1061       iter.next();
1062       inputs = iter.get_dimensions();
1063       assert(rsize == 1, "");
1064       depth = rsize - inputs;
1065     }
1066     break;
1067 
1068   case Bytecodes::_ireturn:
1069   case Bytecodes::_lreturn:
1070   case Bytecodes::_freturn:
1071   case Bytecodes::_dreturn:
1072   case Bytecodes::_areturn:
1073     assert(rsize = -depth, "");
1074     inputs = rsize;
1075     break;
1076 
1077   case Bytecodes::_jsr:
1078   case Bytecodes::_jsr_w:
1079     inputs = 0;
1080     depth  = 1;                  // S.B. depth=1, not zero
1081     break;
1082 
1083   default:
1084     // bytecode produces a typed result
1085     inputs = rsize - depth;
1086     assert(inputs >= 0, "");
1087     break;
1088   }
1089 
1090 #ifdef ASSERT
1091   // spot check
1092   int outputs = depth + inputs;
1093   assert(outputs >= 0, "sanity");
1094   switch (code) {
1095   case Bytecodes::_checkcast: assert(inputs == 1 && outputs == 1, ""); break;
1096   case Bytecodes::_athrow:    assert(inputs == 1 && outputs == 0, ""); break;
1097   case Bytecodes::_aload_0:   assert(inputs == 0 && outputs == 1, ""); break;
1098   case Bytecodes::_return:    assert(inputs == 0 && outputs == 0, ""); break;
1099   case Bytecodes::_drem:      assert(inputs == 4 && outputs == 2, ""); break;
1100   }
1101 #endif //ASSERT
1102 
1103   return true;
1104 }
1105 
1106 
1107 
1108 //------------------------------basic_plus_adr---------------------------------
1109 Node* GraphKit::basic_plus_adr(Node* base, Node* ptr, Node* offset) {
1110   // short-circuit a common case
1111   if (offset == intcon(0))  return ptr;
1112   return _gvn.transform( new (C) AddPNode(base, ptr, offset) );
1113 }
1114 
1115 Node* GraphKit::ConvI2L(Node* offset) {
1116   // short-circuit a common case
1117   jint offset_con = find_int_con(offset, Type::OffsetBot);
1118   if (offset_con != Type::OffsetBot) {
1119     return longcon((jlong) offset_con);
1120   }
1121   return _gvn.transform( new (C) ConvI2LNode(offset));
1122 }
1123 Node* GraphKit::ConvL2I(Node* offset) {
1124   // short-circuit a common case
1125   jlong offset_con = find_long_con(offset, (jlong)Type::OffsetBot);
1126   if (offset_con != (jlong)Type::OffsetBot) {
1127     return intcon((int) offset_con);
1128   }
1129   return _gvn.transform( new (C) ConvL2INode(offset));
1130 }
1131 
1132 //-------------------------load_object_klass-----------------------------------
1133 Node* GraphKit::load_object_klass(Node* obj) {
1134   // Special-case a fresh allocation to avoid building nodes:
1135   Node* akls = AllocateNode::Ideal_klass(obj, &_gvn);
1136   if (akls != NULL)  return akls;
1137   Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes());
1138   return _gvn.transform( LoadKlassNode::make(_gvn, immutable_memory(), k_adr, TypeInstPtr::KLASS) );
1139 }
1140 
1141 //-------------------------load_array_length-----------------------------------
1142 Node* GraphKit::load_array_length(Node* array) {
1143   // Special-case a fresh allocation to avoid building nodes:
1144   AllocateArrayNode* alloc = AllocateArrayNode::Ideal_array_allocation(array, &_gvn);
1145   Node *alen;
1146   if (alloc == NULL) {
1147     Node *r_adr = basic_plus_adr(array, arrayOopDesc::length_offset_in_bytes());
1148     alen = _gvn.transform( new (C) LoadRangeNode(0, immutable_memory(), r_adr, TypeInt::POS));
1149   } else {
1150     alen = alloc->Ideal_length();
1151     Node* ccast = alloc->make_ideal_length(_gvn.type(array)->is_oopptr(), &_gvn);
1152     if (ccast != alen) {
1153       alen = _gvn.transform(ccast);
1154     }
1155   }
1156   return alen;
1157 }
1158 
1159 //------------------------------do_null_check----------------------------------
1160 // Helper function to do a NULL pointer check.  Returned value is
1161 // the incoming address with NULL casted away.  You are allowed to use the
1162 // not-null value only if you are control dependent on the test.
1163 extern int explicit_null_checks_inserted,
1164            explicit_null_checks_elided;
1165 Node* GraphKit::null_check_common(Node* value, BasicType type,
1166                                   // optional arguments for variations:
1167                                   bool assert_null,
1168                                   Node* *null_control) {
1169   assert(!assert_null || null_control == NULL, "not both at once");
1170   if (stopped())  return top();
1171   if (!GenerateCompilerNullChecks && !assert_null && null_control == NULL) {
1172     // For some performance testing, we may wish to suppress null checking.
1173     value = cast_not_null(value);   // Make it appear to be non-null (4962416).
1174     return value;
1175   }
1176   explicit_null_checks_inserted++;
1177 
1178   // Construct NULL check
1179   Node *chk = NULL;
1180   switch(type) {
1181     case T_LONG   : chk = new (C) CmpLNode(value, _gvn.zerocon(T_LONG)); break;
1182     case T_INT    : chk = new (C) CmpINode(value, _gvn.intcon(0)); break;
1183     case T_ARRAY  : // fall through
1184       type = T_OBJECT;  // simplify further tests
1185     case T_OBJECT : {
1186       const Type *t = _gvn.type( value );
1187 
1188       const TypeOopPtr* tp = t->isa_oopptr();
1189       if (tp != NULL && tp->klass() != NULL && !tp->klass()->is_loaded()
1190           // Only for do_null_check, not any of its siblings:
1191           && !assert_null && null_control == NULL) {
1192         // Usually, any field access or invocation on an unloaded oop type
1193         // will simply fail to link, since the statically linked class is
1194         // likely also to be unloaded.  However, in -Xcomp mode, sometimes
1195         // the static class is loaded but the sharper oop type is not.
1196         // Rather than checking for this obscure case in lots of places,
1197         // we simply observe that a null check on an unloaded class
1198         // will always be followed by a nonsense operation, so we
1199         // can just issue the uncommon trap here.
1200         // Our access to the unloaded class will only be correct
1201         // after it has been loaded and initialized, which requires
1202         // a trip through the interpreter.
1203 #ifndef PRODUCT
1204         if (WizardMode) { tty->print("Null check of unloaded "); tp->klass()->print(); tty->cr(); }
1205 #endif
1206         uncommon_trap(Deoptimization::Reason_unloaded,
1207                       Deoptimization::Action_reinterpret,
1208                       tp->klass(), "!loaded");
1209         return top();
1210       }
1211 
1212       if (assert_null) {
1213         // See if the type is contained in NULL_PTR.
1214         // If so, then the value is already null.
1215         if (t->higher_equal(TypePtr::NULL_PTR)) {
1216           explicit_null_checks_elided++;
1217           return value;           // Elided null assert quickly!
1218         }
1219       } else {
1220         // See if mixing in the NULL pointer changes type.
1221         // If so, then the NULL pointer was not allowed in the original
1222         // type.  In other words, "value" was not-null.
1223         if (t->meet(TypePtr::NULL_PTR) != t) {
1224           // same as: if (!TypePtr::NULL_PTR->higher_equal(t)) ...
1225           explicit_null_checks_elided++;
1226           return value;           // Elided null check quickly!
1227         }
1228       }
1229       chk = new (C) CmpPNode( value, null() );
1230       break;
1231     }
1232 
1233     default:
1234       fatal(err_msg_res("unexpected type: %s", type2name(type)));
1235   }
1236   assert(chk != NULL, "sanity check");
1237   chk = _gvn.transform(chk);
1238 
1239   BoolTest::mask btest = assert_null ? BoolTest::eq : BoolTest::ne;
1240   BoolNode *btst = new (C) BoolNode( chk, btest);
1241   Node   *tst = _gvn.transform( btst );
1242 
1243   //-----------
1244   // if peephole optimizations occurred, a prior test existed.
1245   // If a prior test existed, maybe it dominates as we can avoid this test.
1246   if (tst != btst && type == T_OBJECT) {
1247     // At this point we want to scan up the CFG to see if we can
1248     // find an identical test (and so avoid this test altogether).
1249     Node *cfg = control();
1250     int depth = 0;
1251     while( depth < 16 ) {       // Limit search depth for speed
1252       if( cfg->Opcode() == Op_IfTrue &&
1253           cfg->in(0)->in(1) == tst ) {
1254         // Found prior test.  Use "cast_not_null" to construct an identical
1255         // CastPP (and hence hash to) as already exists for the prior test.
1256         // Return that casted value.
1257         if (assert_null) {
1258           replace_in_map(value, null());
1259           return null();  // do not issue the redundant test
1260         }
1261         Node *oldcontrol = control();
1262         set_control(cfg);
1263         Node *res = cast_not_null(value);
1264         set_control(oldcontrol);
1265         explicit_null_checks_elided++;
1266         return res;
1267       }
1268       cfg = IfNode::up_one_dom(cfg, /*linear_only=*/ true);
1269       if (cfg == NULL)  break;  // Quit at region nodes
1270       depth++;
1271     }
1272   }
1273 
1274   //-----------
1275   // Branch to failure if null
1276   float ok_prob = PROB_MAX;  // a priori estimate:  nulls never happen
1277   Deoptimization::DeoptReason reason;
1278   if (assert_null)
1279     reason = Deoptimization::Reason_null_assert;
1280   else if (type == T_OBJECT)
1281     reason = Deoptimization::Reason_null_check;
1282   else
1283     reason = Deoptimization::Reason_div0_check;
1284 
1285   // %%% Since Reason_unhandled is not recorded on a per-bytecode basis,
1286   // ciMethodData::has_trap_at will return a conservative -1 if any
1287   // must-be-null assertion has failed.  This could cause performance
1288   // problems for a method after its first do_null_assert failure.
1289   // Consider using 'Reason_class_check' instead?
1290 
1291   // To cause an implicit null check, we set the not-null probability
1292   // to the maximum (PROB_MAX).  For an explicit check the probability
1293   // is set to a smaller value.
1294   if (null_control != NULL || too_many_traps(reason)) {
1295     // probability is less likely
1296     ok_prob =  PROB_LIKELY_MAG(3);
1297   } else if (!assert_null &&
1298              (ImplicitNullCheckThreshold > 0) &&
1299              method() != NULL &&
1300              (method()->method_data()->trap_count(reason)
1301               >= (uint)ImplicitNullCheckThreshold)) {
1302     ok_prob =  PROB_LIKELY_MAG(3);
1303   }
1304 
1305   if (null_control != NULL) {
1306     IfNode* iff = create_and_map_if(control(), tst, ok_prob, COUNT_UNKNOWN);
1307     Node* null_true = _gvn.transform( new (C) IfFalseNode(iff));
1308     set_control(      _gvn.transform( new (C) IfTrueNode(iff)));
1309     if (null_true == top())
1310       explicit_null_checks_elided++;
1311     (*null_control) = null_true;
1312   } else {
1313     BuildCutout unless(this, tst, ok_prob);
1314     // Check for optimizer eliding test at parse time
1315     if (stopped()) {
1316       // Failure not possible; do not bother making uncommon trap.
1317       explicit_null_checks_elided++;
1318     } else if (assert_null) {
1319       uncommon_trap(reason,
1320                     Deoptimization::Action_make_not_entrant,
1321                     NULL, "assert_null");
1322     } else {
1323       replace_in_map(value, zerocon(type));
1324       builtin_throw(reason);
1325     }
1326   }
1327 
1328   // Must throw exception, fall-thru not possible?
1329   if (stopped()) {
1330     return top();               // No result
1331   }
1332 
1333   if (assert_null) {
1334     // Cast obj to null on this path.
1335     replace_in_map(value, zerocon(type));
1336     return zerocon(type);
1337   }
1338 
1339   // Cast obj to not-null on this path, if there is no null_control.
1340   // (If there is a null_control, a non-null value may come back to haunt us.)
1341   if (type == T_OBJECT) {
1342     Node* cast = cast_not_null(value, false);
1343     if (null_control == NULL || (*null_control) == top())
1344       replace_in_map(value, cast);
1345     value = cast;
1346   }
1347 
1348   return value;
1349 }
1350 
1351 
1352 //------------------------------cast_not_null----------------------------------
1353 // Cast obj to not-null on this path
1354 Node* GraphKit::cast_not_null(Node* obj, bool do_replace_in_map) {
1355   const Type *t = _gvn.type(obj);
1356   const Type *t_not_null = t->join(TypePtr::NOTNULL);
1357   // Object is already not-null?
1358   if( t == t_not_null ) return obj;
1359 
1360   Node *cast = new (C) CastPPNode(obj,t_not_null);
1361   cast->init_req(0, control());
1362   cast = _gvn.transform( cast );
1363 
1364   // Scan for instances of 'obj' in the current JVM mapping.
1365   // These instances are known to be not-null after the test.
1366   if (do_replace_in_map)
1367     replace_in_map(obj, cast);
1368 
1369   return cast;                  // Return casted value
1370 }
1371 
1372 
1373 //--------------------------replace_in_map-------------------------------------
1374 void GraphKit::replace_in_map(Node* old, Node* neww) {
1375   this->map()->replace_edge(old, neww);
1376 
1377   // Note: This operation potentially replaces any edge
1378   // on the map.  This includes locals, stack, and monitors
1379   // of the current (innermost) JVM state.
1380 
1381   // We can consider replacing in caller maps.
1382   // The idea would be that an inlined function's null checks
1383   // can be shared with the entire inlining tree.
1384   // The expense of doing this is that the PreserveJVMState class
1385   // would have to preserve caller states too, with a deep copy.
1386 }
1387 
1388 
1389 //=============================================================================
1390 //--------------------------------memory---------------------------------------
1391 Node* GraphKit::memory(uint alias_idx) {
1392   MergeMemNode* mem = merged_memory();
1393   Node* p = mem->memory_at(alias_idx);
1394   _gvn.set_type(p, Type::MEMORY);  // must be mapped
1395   return p;
1396 }
1397 
1398 //-----------------------------reset_memory------------------------------------
1399 Node* GraphKit::reset_memory() {
1400   Node* mem = map()->memory();
1401   // do not use this node for any more parsing!
1402   debug_only( map()->set_memory((Node*)NULL) );
1403   return _gvn.transform( mem );
1404 }
1405 
1406 //------------------------------set_all_memory---------------------------------
1407 void GraphKit::set_all_memory(Node* newmem) {
1408   Node* mergemem = MergeMemNode::make(C, newmem);
1409   gvn().set_type_bottom(mergemem);
1410   map()->set_memory(mergemem);
1411 }
1412 
1413 //------------------------------set_all_memory_call----------------------------
1414 void GraphKit::set_all_memory_call(Node* call, bool separate_io_proj) {
1415   Node* newmem = _gvn.transform( new (C) ProjNode(call, TypeFunc::Memory, separate_io_proj) );
1416   set_all_memory(newmem);
1417 }
1418 
1419 //=============================================================================
1420 //
1421 // parser factory methods for MemNodes
1422 //
1423 // These are layered on top of the factory methods in LoadNode and StoreNode,
1424 // and integrate with the parser's memory state and _gvn engine.
1425 //
1426 
1427 // factory methods in "int adr_idx"
1428 Node* GraphKit::make_load(Node* ctl, Node* adr, const Type* t, BasicType bt,
1429                           int adr_idx,
1430                           bool require_atomic_access) {
1431   assert(adr_idx != Compile::AliasIdxTop, "use other make_load factory" );
1432   const TypePtr* adr_type = NULL; // debug-mode-only argument
1433   debug_only(adr_type = C->get_adr_type(adr_idx));
1434   Node* mem = memory(adr_idx);
1435   Node* ld;
1436   if (require_atomic_access && bt == T_LONG) {
1437     ld = LoadLNode::make_atomic(C, ctl, mem, adr, adr_type, t);
1438   } else {
1439     ld = LoadNode::make(_gvn, ctl, mem, adr, adr_type, t, bt);
1440   }
1441   return _gvn.transform(ld);
1442 }
1443 
1444 Node* GraphKit::store_to_memory(Node* ctl, Node* adr, Node *val, BasicType bt,
1445                                 int adr_idx,
1446                                 bool require_atomic_access) {
1447   assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
1448   const TypePtr* adr_type = NULL;
1449   debug_only(adr_type = C->get_adr_type(adr_idx));
1450   Node *mem = memory(adr_idx);
1451   Node* st;
1452   if (require_atomic_access && bt == T_LONG) {
1453     st = StoreLNode::make_atomic(C, ctl, mem, adr, adr_type, val);
1454   } else {
1455     st = StoreNode::make(_gvn, ctl, mem, adr, adr_type, val, bt);
1456   }
1457   st = _gvn.transform(st);
1458   set_memory(st, adr_idx);
1459   // Back-to-back stores can only remove intermediate store with DU info
1460   // so push on worklist for optimizer.
1461   if (mem->req() > MemNode::Address && adr == mem->in(MemNode::Address))
1462     record_for_igvn(st);
1463 
1464   return st;
1465 }
1466 
1467 
1468 void GraphKit::pre_barrier(bool do_load,
1469                            Node* ctl,
1470                            Node* obj,
1471                            Node* adr,
1472                            uint  adr_idx,
1473                            Node* val,
1474                            const TypeOopPtr* val_type,
1475                            Node* pre_val,
1476                            BasicType bt) {
1477 
1478   BarrierSet* bs = Universe::heap()->barrier_set();
1479   set_control(ctl);
1480   switch (bs->kind()) {
1481     case BarrierSet::G1SATBCT:
1482     case BarrierSet::G1SATBCTLogging:
1483       g1_write_barrier_pre(do_load, obj, adr, adr_idx, val, val_type, pre_val, bt);
1484       break;
1485 
1486     case BarrierSet::CardTableModRef:
1487     case BarrierSet::CardTableExtension:
1488     case BarrierSet::ModRef:
1489       break;
1490 
1491     case BarrierSet::Other:
1492     default      :
1493       ShouldNotReachHere();
1494 
1495   }
1496 }
1497 
1498 void GraphKit::post_barrier(Node* ctl,
1499                             Node* store,
1500                             Node* obj,
1501                             Node* adr,
1502                             uint  adr_idx,
1503                             Node* val,
1504                             BasicType bt,
1505                             bool use_precise) {
1506   BarrierSet* bs = Universe::heap()->barrier_set();
1507   set_control(ctl);
1508   switch (bs->kind()) {
1509     case BarrierSet::G1SATBCT:
1510     case BarrierSet::G1SATBCTLogging:
1511       g1_write_barrier_post(store, obj, adr, adr_idx, val, bt, use_precise);
1512       break;
1513 
1514     case BarrierSet::CardTableModRef:
1515     case BarrierSet::CardTableExtension:
1516       write_barrier_post(store, obj, adr, adr_idx, val, use_precise);
1517       break;
1518 
1519     case BarrierSet::ModRef:
1520       break;
1521 
1522     case BarrierSet::Other:
1523     default      :
1524       ShouldNotReachHere();
1525 
1526   }
1527 }
1528 
1529 Node* GraphKit::store_oop(Node* ctl,
1530                           Node* obj,
1531                           Node* adr,
1532                           const TypePtr* adr_type,
1533                           Node* val,
1534                           const TypeOopPtr* val_type,
1535                           BasicType bt,
1536                           bool use_precise) {
1537   // Transformation of a value which could be NULL pointer (CastPP #NULL)
1538   // could be delayed during Parse (for example, in adjust_map_after_if()).
1539   // Execute transformation here to avoid barrier generation in such case.
1540   if (_gvn.type(val) == TypePtr::NULL_PTR)
1541     val = _gvn.makecon(TypePtr::NULL_PTR);
1542 
1543   set_control(ctl);
1544   if (stopped()) return top(); // Dead path ?
1545 
1546   assert(bt == T_OBJECT, "sanity");
1547   assert(val != NULL, "not dead path");
1548   uint adr_idx = C->get_alias_index(adr_type);
1549   assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
1550 
1551   pre_barrier(true /* do_load */,
1552               control(), obj, adr, adr_idx, val, val_type,
1553               NULL /* pre_val */,
1554               bt);
1555 
1556   Node* store = store_to_memory(control(), adr, val, bt, adr_idx);
1557   post_barrier(control(), store, obj, adr, adr_idx, val, bt, use_precise);
1558   return store;
1559 }
1560 
1561 // Could be an array or object we don't know at compile time (unsafe ref.)
1562 Node* GraphKit::store_oop_to_unknown(Node* ctl,
1563                              Node* obj,   // containing obj
1564                              Node* adr,  // actual adress to store val at
1565                              const TypePtr* adr_type,
1566                              Node* val,
1567                              BasicType bt) {
1568   Compile::AliasType* at = C->alias_type(adr_type);
1569   const TypeOopPtr* val_type = NULL;
1570   if (adr_type->isa_instptr()) {
1571     if (at->field() != NULL) {
1572       // known field.  This code is a copy of the do_put_xxx logic.
1573       ciField* field = at->field();
1574       if (!field->type()->is_loaded()) {
1575         val_type = TypeInstPtr::BOTTOM;
1576       } else {
1577         val_type = TypeOopPtr::make_from_klass(field->type()->as_klass());
1578       }
1579     }
1580   } else if (adr_type->isa_aryptr()) {
1581     val_type = adr_type->is_aryptr()->elem()->make_oopptr();
1582   }
1583   if (val_type == NULL) {
1584     val_type = TypeInstPtr::BOTTOM;
1585   }
1586   return store_oop(ctl, obj, adr, adr_type, val, val_type, bt, true);
1587 }
1588 
1589 
1590 //-------------------------array_element_address-------------------------
1591 Node* GraphKit::array_element_address(Node* ary, Node* idx, BasicType elembt,
1592                                       const TypeInt* sizetype) {
1593   uint shift  = exact_log2(type2aelembytes(elembt));
1594   uint header = arrayOopDesc::base_offset_in_bytes(elembt);
1595 
1596   // short-circuit a common case (saves lots of confusing waste motion)
1597   jint idx_con = find_int_con(idx, -1);
1598   if (idx_con >= 0) {
1599     intptr_t offset = header + ((intptr_t)idx_con << shift);
1600     return basic_plus_adr(ary, offset);
1601   }
1602 
1603   // must be correct type for alignment purposes
1604   Node* base  = basic_plus_adr(ary, header);
1605 #ifdef _LP64
1606   // The scaled index operand to AddP must be a clean 64-bit value.
1607   // Java allows a 32-bit int to be incremented to a negative
1608   // value, which appears in a 64-bit register as a large
1609   // positive number.  Using that large positive number as an
1610   // operand in pointer arithmetic has bad consequences.
1611   // On the other hand, 32-bit overflow is rare, and the possibility
1612   // can often be excluded, if we annotate the ConvI2L node with
1613   // a type assertion that its value is known to be a small positive
1614   // number.  (The prior range check has ensured this.)
1615   // This assertion is used by ConvI2LNode::Ideal.
1616   int index_max = max_jint - 1;  // array size is max_jint, index is one less
1617   if (sizetype != NULL)  index_max = sizetype->_hi - 1;
1618   const TypeLong* lidxtype = TypeLong::make(CONST64(0), index_max, Type::WidenMax);
1619   idx = _gvn.transform( new (C) ConvI2LNode(idx, lidxtype) );
1620 #endif
1621   Node* scale = _gvn.transform( new (C) LShiftXNode(idx, intcon(shift)) );
1622   return basic_plus_adr(ary, base, scale);
1623 }
1624 
1625 //-------------------------load_array_element-------------------------
1626 Node* GraphKit::load_array_element(Node* ctl, Node* ary, Node* idx, const TypeAryPtr* arytype) {
1627   const Type* elemtype = arytype->elem();
1628   BasicType elembt = elemtype->array_element_basic_type();
1629   Node* adr = array_element_address(ary, idx, elembt, arytype->size());
1630   Node* ld = make_load(ctl, adr, elemtype, elembt, arytype);
1631   return ld;
1632 }
1633 
1634 //-------------------------set_arguments_for_java_call-------------------------
1635 // Arguments (pre-popped from the stack) are taken from the JVMS.
1636 void GraphKit::set_arguments_for_java_call(CallJavaNode* call) {
1637   // Add the call arguments:
1638   uint nargs = call->method()->arg_size();
1639   for (uint i = 0; i < nargs; i++) {
1640     Node* arg = argument(i);
1641     call->init_req(i + TypeFunc::Parms, arg);
1642   }
1643 }
1644 
1645 //---------------------------set_edges_for_java_call---------------------------
1646 // Connect a newly created call into the current JVMS.
1647 // A return value node (if any) is returned from set_edges_for_java_call.
1648 void GraphKit::set_edges_for_java_call(CallJavaNode* call, bool must_throw, bool separate_io_proj) {
1649 
1650   // Add the predefined inputs:
1651   call->init_req( TypeFunc::Control, control() );
1652   call->init_req( TypeFunc::I_O    , i_o() );
1653   call->init_req( TypeFunc::Memory , reset_memory() );
1654   call->init_req( TypeFunc::FramePtr, frameptr() );
1655   call->init_req( TypeFunc::ReturnAdr, top() );
1656 
1657   add_safepoint_edges(call, must_throw);
1658 
1659   Node* xcall = _gvn.transform(call);
1660 
1661   if (xcall == top()) {
1662     set_control(top());
1663     return;
1664   }
1665   assert(xcall == call, "call identity is stable");
1666 
1667   // Re-use the current map to produce the result.
1668 
1669   set_control(_gvn.transform(new (C) ProjNode(call, TypeFunc::Control)));
1670   set_i_o(    _gvn.transform(new (C) ProjNode(call, TypeFunc::I_O    , separate_io_proj)));
1671   set_all_memory_call(xcall, separate_io_proj);
1672 
1673   //return xcall;   // no need, caller already has it
1674 }
1675 
1676 Node* GraphKit::set_results_for_java_call(CallJavaNode* call, bool separate_io_proj) {
1677   if (stopped())  return top();  // maybe the call folded up?
1678 
1679   // Capture the return value, if any.
1680   Node* ret;
1681   if (call->method() == NULL ||
1682       call->method()->return_type()->basic_type() == T_VOID)
1683         ret = top();
1684   else  ret = _gvn.transform(new (C) ProjNode(call, TypeFunc::Parms));
1685 
1686   // Note:  Since any out-of-line call can produce an exception,
1687   // we always insert an I_O projection from the call into the result.
1688 
1689   make_slow_call_ex(call, env()->Throwable_klass(), separate_io_proj);
1690 
1691   if (separate_io_proj) {
1692     // The caller requested separate projections be used by the fall
1693     // through and exceptional paths, so replace the projections for
1694     // the fall through path.
1695     set_i_o(_gvn.transform( new (C) ProjNode(call, TypeFunc::I_O) ));
1696     set_all_memory(_gvn.transform( new (C) ProjNode(call, TypeFunc::Memory) ));
1697   }
1698   return ret;
1699 }
1700 
1701 //--------------------set_predefined_input_for_runtime_call--------------------
1702 // Reading and setting the memory state is way conservative here.
1703 // The real problem is that I am not doing real Type analysis on memory,
1704 // so I cannot distinguish card mark stores from other stores.  Across a GC
1705 // point the Store Barrier and the card mark memory has to agree.  I cannot
1706 // have a card mark store and its barrier split across the GC point from
1707 // either above or below.  Here I get that to happen by reading ALL of memory.
1708 // A better answer would be to separate out card marks from other memory.
1709 // For now, return the input memory state, so that it can be reused
1710 // after the call, if this call has restricted memory effects.
1711 Node* GraphKit::set_predefined_input_for_runtime_call(SafePointNode* call) {
1712   // Set fixed predefined input arguments
1713   Node* memory = reset_memory();
1714   call->init_req( TypeFunc::Control,   control()  );
1715   call->init_req( TypeFunc::I_O,       top()      ); // does no i/o
1716   call->init_req( TypeFunc::Memory,    memory     ); // may gc ptrs
1717   call->init_req( TypeFunc::FramePtr,  frameptr() );
1718   call->init_req( TypeFunc::ReturnAdr, top()      );
1719   return memory;
1720 }
1721 
1722 //-------------------set_predefined_output_for_runtime_call--------------------
1723 // Set control and memory (not i_o) from the call.
1724 // If keep_mem is not NULL, use it for the output state,
1725 // except for the RawPtr output of the call, if hook_mem is TypeRawPtr::BOTTOM.
1726 // If hook_mem is NULL, this call produces no memory effects at all.
1727 // If hook_mem is a Java-visible memory slice (such as arraycopy operands),
1728 // then only that memory slice is taken from the call.
1729 // In the last case, we must put an appropriate memory barrier before
1730 // the call, so as to create the correct anti-dependencies on loads
1731 // preceding the call.
1732 void GraphKit::set_predefined_output_for_runtime_call(Node* call,
1733                                                       Node* keep_mem,
1734                                                       const TypePtr* hook_mem) {
1735   // no i/o
1736   set_control(_gvn.transform( new (C) ProjNode(call,TypeFunc::Control) ));
1737   if (keep_mem) {
1738     // First clone the existing memory state
1739     set_all_memory(keep_mem);
1740     if (hook_mem != NULL) {
1741       // Make memory for the call
1742       Node* mem = _gvn.transform( new (C) ProjNode(call, TypeFunc::Memory) );
1743       // Set the RawPtr memory state only.  This covers all the heap top/GC stuff
1744       // We also use hook_mem to extract specific effects from arraycopy stubs.
1745       set_memory(mem, hook_mem);
1746     }
1747     // ...else the call has NO memory effects.
1748 
1749     // Make sure the call advertises its memory effects precisely.
1750     // This lets us build accurate anti-dependences in gcm.cpp.
1751     assert(C->alias_type(call->adr_type()) == C->alias_type(hook_mem),
1752            "call node must be constructed correctly");
1753   } else {
1754     assert(hook_mem == NULL, "");
1755     // This is not a "slow path" call; all memory comes from the call.
1756     set_all_memory_call(call);
1757   }
1758 }
1759 
1760 
1761 // Replace the call with the current state of the kit.
1762 void GraphKit::replace_call(CallNode* call, Node* result) {
1763   JVMState* ejvms = NULL;
1764   if (has_exceptions()) {
1765     ejvms = transfer_exceptions_into_jvms();
1766   }
1767 
1768   SafePointNode* final_state = stop();
1769 
1770   // Find all the needed outputs of this call
1771   CallProjections callprojs;
1772   call->extract_projections(&callprojs, true);
1773 
1774   Node* init_mem = call->in(TypeFunc::Memory);
1775   Node* final_mem = final_state->in(TypeFunc::Memory);
1776   Node* final_ctl = final_state->in(TypeFunc::Control);
1777   Node* final_io = final_state->in(TypeFunc::I_O);
1778   
1779   // Replace all the old call edges with the edges from the inlining result
1780   if (callprojs.fallthrough_catchproj != NULL) {
1781     C->gvn_replace_by(callprojs.fallthrough_catchproj, final_ctl);
1782   }
1783   if (callprojs.fallthrough_memproj != NULL) {
1784     C->gvn_replace_by(callprojs.fallthrough_memproj,   final_mem);
1785   }
1786   if (callprojs.fallthrough_ioproj != NULL) {
1787     C->gvn_replace_by(callprojs.fallthrough_ioproj,    final_io);
1788   }
1789 
1790   // Replace the result with the new result if it exists and is used
1791   if (callprojs.resproj != NULL && result != NULL) {
1792     C->gvn_replace_by(callprojs.resproj, result);
1793   }
1794 
1795   if (ejvms == NULL) {
1796     // No exception edges to simply kill off those paths
1797     C->gvn_replace_by(callprojs.catchall_catchproj, C->top());
1798     C->gvn_replace_by(callprojs.catchall_memproj,   C->top());
1799     C->gvn_replace_by(callprojs.catchall_ioproj,    C->top());
1800 
1801     // Replace the old exception object with top
1802     if (callprojs.exobj != NULL) {
1803       C->gvn_replace_by(callprojs.exobj, C->top());
1804     }
1805   } else {
1806     GraphKit ekit(ejvms);
1807 
1808     // Load my combined exception state into the kit, with all phis transformed:
1809     SafePointNode* ex_map = ekit.combine_and_pop_all_exception_states();
1810 
1811     Node* ex_oop = ekit.use_exception_state(ex_map);
1812 
1813     C->gvn_replace_by(callprojs.catchall_catchproj, ekit.control());
1814     C->gvn_replace_by(callprojs.catchall_memproj,   ekit.reset_memory());
1815     C->gvn_replace_by(callprojs.catchall_ioproj,    ekit.i_o());
1816 
1817     // Replace the old exception object with the newly created one
1818     if (callprojs.exobj != NULL) {
1819       C->gvn_replace_by(callprojs.exobj, ex_oop);
1820     }
1821   }
1822 
1823   // Disconnect the call from the graph
1824   call->disconnect_inputs(NULL, C);
1825   C->gvn_replace_by(call, C->top());
1826 
1827   // Clean up any MergeMems that feed other MergeMems since the
1828   // optimizer doesn't like that.
1829   if (final_mem->is_MergeMem()) {
1830     Node_List wl;
1831     for (SimpleDUIterator i(final_mem); i.has_next(); i.next()) {
1832       Node* m = i.get();
1833       if (m->is_MergeMem() && !wl.contains(m)) {
1834         wl.push(m);
1835       }
1836     }
1837     while (wl.size()  > 0) {
1838       _gvn.transform(wl.pop());
1839     }
1840   }
1841 }
1842 
1843 
1844 //------------------------------increment_counter------------------------------
1845 // for statistics: increment a VM counter by 1
1846 
1847 void GraphKit::increment_counter(address counter_addr) {
1848   Node* adr1 = makecon(TypeRawPtr::make(counter_addr));
1849   increment_counter(adr1);
1850 }
1851 
1852 void GraphKit::increment_counter(Node* counter_addr) {
1853   int adr_type = Compile::AliasIdxRaw;
1854   Node* ctrl = control();
1855   Node* cnt  = make_load(ctrl, counter_addr, TypeInt::INT, T_INT, adr_type);
1856   Node* incr = _gvn.transform(new (C) AddINode(cnt, _gvn.intcon(1)));
1857   store_to_memory( ctrl, counter_addr, incr, T_INT, adr_type );
1858 }
1859 
1860 
1861 //------------------------------uncommon_trap----------------------------------
1862 // Bail out to the interpreter in mid-method.  Implemented by calling the
1863 // uncommon_trap blob.  This helper function inserts a runtime call with the
1864 // right debug info.
1865 void GraphKit::uncommon_trap(int trap_request,
1866                              ciKlass* klass, const char* comment,
1867                              bool must_throw,
1868                              bool keep_exact_action) {
1869   if (failing())  stop();
1870   if (stopped())  return; // trap reachable?
1871 
1872   // Note:  If ProfileTraps is true, and if a deopt. actually
1873   // occurs here, the runtime will make sure an MDO exists.  There is
1874   // no need to call method()->ensure_method_data() at this point.
1875 
1876   // Set the stack pointer to the right value for reexecution:
1877   set_sp(reexecute_sp());
1878 
1879 #ifdef ASSERT
1880   if (!must_throw) {
1881     // Make sure the stack has at least enough depth to execute
1882     // the current bytecode.
1883     int inputs, ignored_depth;
1884     if (compute_stack_effects(inputs, ignored_depth)) {
1885       assert(sp() >= inputs, err_msg_res("must have enough JVMS stack to execute %s: sp=%d, inputs=%d",
1886              Bytecodes::name(java_bc()), sp(), inputs));
1887     }
1888   }
1889 #endif
1890 
1891   Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(trap_request);
1892   Deoptimization::DeoptAction action = Deoptimization::trap_request_action(trap_request);
1893 
1894   switch (action) {
1895   case Deoptimization::Action_maybe_recompile:
1896   case Deoptimization::Action_reinterpret:
1897     // Temporary fix for 6529811 to allow virtual calls to be sure they
1898     // get the chance to go from mono->bi->mega
1899     if (!keep_exact_action &&
1900         Deoptimization::trap_request_index(trap_request) < 0 &&
1901         too_many_recompiles(reason)) {
1902       // This BCI is causing too many recompilations.
1903       action = Deoptimization::Action_none;
1904       trap_request = Deoptimization::make_trap_request(reason, action);
1905     } else {
1906       C->set_trap_can_recompile(true);
1907     }
1908     break;
1909   case Deoptimization::Action_make_not_entrant:
1910     C->set_trap_can_recompile(true);
1911     break;
1912 #ifdef ASSERT
1913   case Deoptimization::Action_none:
1914   case Deoptimization::Action_make_not_compilable:
1915     break;
1916   default:
1917     fatal(err_msg_res("unknown action %d: %s", action, Deoptimization::trap_action_name(action)));
1918     break;
1919 #endif
1920   }
1921 
1922   if (TraceOptoParse) {
1923     char buf[100];
1924     tty->print_cr("Uncommon trap %s at bci:%d",
1925                   Deoptimization::format_trap_request(buf, sizeof(buf),
1926                                                       trap_request), bci());
1927   }
1928 
1929   CompileLog* log = C->log();
1930   if (log != NULL) {
1931     int kid = (klass == NULL)? -1: log->identify(klass);
1932     log->begin_elem("uncommon_trap bci='%d'", bci());
1933     char buf[100];
1934     log->print(" %s", Deoptimization::format_trap_request(buf, sizeof(buf),
1935                                                           trap_request));
1936     if (kid >= 0)         log->print(" klass='%d'", kid);
1937     if (comment != NULL)  log->print(" comment='%s'", comment);
1938     log->end_elem();
1939   }
1940 
1941   // Make sure any guarding test views this path as very unlikely
1942   Node *i0 = control()->in(0);
1943   if (i0 != NULL && i0->is_If()) {        // Found a guarding if test?
1944     IfNode *iff = i0->as_If();
1945     float f = iff->_prob;   // Get prob
1946     if (control()->Opcode() == Op_IfTrue) {
1947       if (f > PROB_UNLIKELY_MAG(4))
1948         iff->_prob = PROB_MIN;
1949     } else {
1950       if (f < PROB_LIKELY_MAG(4))
1951         iff->_prob = PROB_MAX;
1952     }
1953   }
1954 
1955   // Clear out dead values from the debug info.
1956   kill_dead_locals();
1957 
1958   // Now insert the uncommon trap subroutine call
1959   address call_addr = SharedRuntime::uncommon_trap_blob()->entry_point();
1960   const TypePtr* no_memory_effects = NULL;
1961   // Pass the index of the class to be loaded
1962   Node* call = make_runtime_call(RC_NO_LEAF | RC_UNCOMMON |
1963                                  (must_throw ? RC_MUST_THROW : 0),
1964                                  OptoRuntime::uncommon_trap_Type(),
1965                                  call_addr, "uncommon_trap", no_memory_effects,
1966                                  intcon(trap_request));
1967   assert(call->as_CallStaticJava()->uncommon_trap_request() == trap_request,
1968          "must extract request correctly from the graph");
1969   assert(trap_request != 0, "zero value reserved by uncommon_trap_request");
1970 
1971   call->set_req(TypeFunc::ReturnAdr, returnadr());
1972   // The debug info is the only real input to this call.
1973 
1974   // Halt-and-catch fire here.  The above call should never return!
1975   HaltNode* halt = new(C) HaltNode(control(), frameptr());
1976   _gvn.set_type_bottom(halt);
1977   root()->add_req(halt);
1978 
1979   stop_and_kill_map();
1980 }
1981 
1982 
1983 //--------------------------just_allocated_object------------------------------
1984 // Report the object that was just allocated.
1985 // It must be the case that there are no intervening safepoints.
1986 // We use this to determine if an object is so "fresh" that
1987 // it does not require card marks.
1988 Node* GraphKit::just_allocated_object(Node* current_control) {
1989   if (C->recent_alloc_ctl() == current_control)
1990     return C->recent_alloc_obj();
1991   return NULL;
1992 }
1993 
1994 
1995 void GraphKit::round_double_arguments(ciMethod* dest_method) {
1996   // (Note:  TypeFunc::make has a cache that makes this fast.)
1997   const TypeFunc* tf    = TypeFunc::make(dest_method);
1998   int             nargs = tf->_domain->_cnt - TypeFunc::Parms;
1999   for (int j = 0; j < nargs; j++) {
2000     const Type *targ = tf->_domain->field_at(j + TypeFunc::Parms);
2001     if( targ->basic_type() == T_DOUBLE ) {
2002       // If any parameters are doubles, they must be rounded before
2003       // the call, dstore_rounding does gvn.transform
2004       Node *arg = argument(j);
2005       arg = dstore_rounding(arg);
2006       set_argument(j, arg);
2007     }
2008   }
2009 }
2010 
2011 void GraphKit::round_double_result(ciMethod* dest_method) {
2012   // A non-strict method may return a double value which has an extended
2013   // exponent, but this must not be visible in a caller which is 'strict'
2014   // If a strict caller invokes a non-strict callee, round a double result
2015 
2016   BasicType result_type = dest_method->return_type()->basic_type();
2017   assert( method() != NULL, "must have caller context");
2018   if( result_type == T_DOUBLE && method()->is_strict() && !dest_method->is_strict() ) {
2019     // Destination method's return value is on top of stack
2020     // dstore_rounding() does gvn.transform
2021     Node *result = pop_pair();
2022     result = dstore_rounding(result);
2023     push_pair(result);
2024   }
2025 }
2026 
2027 // rounding for strict float precision conformance
2028 Node* GraphKit::precision_rounding(Node* n) {
2029   return UseStrictFP && _method->flags().is_strict()
2030     && UseSSE == 0 && Matcher::strict_fp_requires_explicit_rounding
2031     ? _gvn.transform( new (C) RoundFloatNode(0, n) )
2032     : n;
2033 }
2034 
2035 // rounding for strict double precision conformance
2036 Node* GraphKit::dprecision_rounding(Node *n) {
2037   return UseStrictFP && _method->flags().is_strict()
2038     && UseSSE <= 1 && Matcher::strict_fp_requires_explicit_rounding
2039     ? _gvn.transform( new (C) RoundDoubleNode(0, n) )
2040     : n;
2041 }
2042 
2043 // rounding for non-strict double stores
2044 Node* GraphKit::dstore_rounding(Node* n) {
2045   return Matcher::strict_fp_requires_explicit_rounding
2046     && UseSSE <= 1
2047     ? _gvn.transform( new (C) RoundDoubleNode(0, n) )
2048     : n;
2049 }
2050 
2051 //=============================================================================
2052 // Generate a fast path/slow path idiom.  Graph looks like:
2053 // [foo] indicates that 'foo' is a parameter
2054 //
2055 //              [in]     NULL
2056 //                 \    /
2057 //                  CmpP
2058 //                  Bool ne
2059 //                   If
2060 //                  /  \
2061 //              True    False-<2>
2062 //              / |
2063 //             /  cast_not_null
2064 //           Load  |    |   ^
2065 //        [fast_test]   |   |
2066 // gvn to   opt_test    |   |
2067 //          /    \      |  <1>
2068 //      True     False  |
2069 //        |         \\  |
2070 //   [slow_call]     \[fast_result]
2071 //    Ctl   Val       \      \
2072 //     |               \      \
2073 //    Catch       <1>   \      \
2074 //   /    \        ^     \      \
2075 //  Ex    No_Ex    |      \      \
2076 //  |       \   \  |       \ <2>  \
2077 //  ...      \  [slow_res] |  |    \   [null_result]
2078 //            \         \--+--+---  |  |
2079 //             \           | /    \ | /
2080 //              --------Region     Phi
2081 //
2082 //=============================================================================
2083 // Code is structured as a series of driver functions all called 'do_XXX' that
2084 // call a set of helper functions.  Helper functions first, then drivers.
2085 
2086 //------------------------------null_check_oop---------------------------------
2087 // Null check oop.  Set null-path control into Region in slot 3.
2088 // Make a cast-not-nullness use the other not-null control.  Return cast.
2089 Node* GraphKit::null_check_oop(Node* value, Node* *null_control,
2090                                bool never_see_null) {
2091   // Initial NULL check taken path
2092   (*null_control) = top();
2093   Node* cast = null_check_common(value, T_OBJECT, false, null_control);
2094 
2095   // Generate uncommon_trap:
2096   if (never_see_null && (*null_control) != top()) {
2097     // If we see an unexpected null at a check-cast we record it and force a
2098     // recompile; the offending check-cast will be compiled to handle NULLs.
2099     // If we see more than one offending BCI, then all checkcasts in the
2100     // method will be compiled to handle NULLs.
2101     PreserveJVMState pjvms(this);
2102     set_control(*null_control);
2103     replace_in_map(value, null());
2104     uncommon_trap(Deoptimization::Reason_null_check,
2105                   Deoptimization::Action_make_not_entrant);
2106     (*null_control) = top();    // NULL path is dead
2107   }
2108 
2109   // Cast away null-ness on the result
2110   return cast;
2111 }
2112 
2113 //------------------------------opt_iff----------------------------------------
2114 // Optimize the fast-check IfNode.  Set the fast-path region slot 2.
2115 // Return slow-path control.
2116 Node* GraphKit::opt_iff(Node* region, Node* iff) {
2117   IfNode *opt_iff = _gvn.transform(iff)->as_If();
2118 
2119   // Fast path taken; set region slot 2
2120   Node *fast_taken = _gvn.transform( new (C) IfFalseNode(opt_iff) );
2121   region->init_req(2,fast_taken); // Capture fast-control
2122 
2123   // Fast path not-taken, i.e. slow path
2124   Node *slow_taken = _gvn.transform( new (C) IfTrueNode(opt_iff) );
2125   return slow_taken;
2126 }
2127 
2128 //-----------------------------make_runtime_call-------------------------------
2129 Node* GraphKit::make_runtime_call(int flags,
2130                                   const TypeFunc* call_type, address call_addr,
2131                                   const char* call_name,
2132                                   const TypePtr* adr_type,
2133                                   // The following parms are all optional.
2134                                   // The first NULL ends the list.
2135                                   Node* parm0, Node* parm1,
2136                                   Node* parm2, Node* parm3,
2137                                   Node* parm4, Node* parm5,
2138                                   Node* parm6, Node* parm7) {
2139   // Slow-path call
2140   bool is_leaf = !(flags & RC_NO_LEAF);
2141   bool has_io  = (!is_leaf && !(flags & RC_NO_IO));
2142   if (call_name == NULL) {
2143     assert(!is_leaf, "must supply name for leaf");
2144     call_name = OptoRuntime::stub_name(call_addr);
2145   }
2146   CallNode* call;
2147   if (!is_leaf) {
2148     call = new(C) CallStaticJavaNode(call_type, call_addr, call_name,
2149                                            bci(), adr_type);
2150   } else if (flags & RC_NO_FP) {
2151     call = new(C) CallLeafNoFPNode(call_type, call_addr, call_name, adr_type);
2152   } else {
2153     call = new(C) CallLeafNode(call_type, call_addr, call_name, adr_type);
2154   }
2155 
2156   // The following is similar to set_edges_for_java_call,
2157   // except that the memory effects of the call are restricted to AliasIdxRaw.
2158 
2159   // Slow path call has no side-effects, uses few values
2160   bool wide_in  = !(flags & RC_NARROW_MEM);
2161   bool wide_out = (C->get_alias_index(adr_type) == Compile::AliasIdxBot);
2162 
2163   Node* prev_mem = NULL;
2164   if (wide_in) {
2165     prev_mem = set_predefined_input_for_runtime_call(call);
2166   } else {
2167     assert(!wide_out, "narrow in => narrow out");
2168     Node* narrow_mem = memory(adr_type);
2169     prev_mem = reset_memory();
2170     map()->set_memory(narrow_mem);
2171     set_predefined_input_for_runtime_call(call);
2172   }
2173 
2174   // Hook each parm in order.  Stop looking at the first NULL.
2175   if (parm0 != NULL) { call->init_req(TypeFunc::Parms+0, parm0);
2176   if (parm1 != NULL) { call->init_req(TypeFunc::Parms+1, parm1);
2177   if (parm2 != NULL) { call->init_req(TypeFunc::Parms+2, parm2);
2178   if (parm3 != NULL) { call->init_req(TypeFunc::Parms+3, parm3);
2179   if (parm4 != NULL) { call->init_req(TypeFunc::Parms+4, parm4);
2180   if (parm5 != NULL) { call->init_req(TypeFunc::Parms+5, parm5);
2181   if (parm6 != NULL) { call->init_req(TypeFunc::Parms+6, parm6);
2182   if (parm7 != NULL) { call->init_req(TypeFunc::Parms+7, parm7);
2183     /* close each nested if ===> */  } } } } } } } }
2184   assert(call->in(call->req()-1) != NULL, "must initialize all parms");
2185 
2186   if (!is_leaf) {
2187     // Non-leaves can block and take safepoints:
2188     add_safepoint_edges(call, ((flags & RC_MUST_THROW) != 0));
2189   }
2190   // Non-leaves can throw exceptions:
2191   if (has_io) {
2192     call->set_req(TypeFunc::I_O, i_o());
2193   }
2194 
2195   if (flags & RC_UNCOMMON) {
2196     // Set the count to a tiny probability.  Cf. Estimate_Block_Frequency.
2197     // (An "if" probability corresponds roughly to an unconditional count.
2198     // Sort of.)
2199     call->set_cnt(PROB_UNLIKELY_MAG(4));
2200   }
2201 
2202   Node* c = _gvn.transform(call);
2203   assert(c == call, "cannot disappear");
2204 
2205   if (wide_out) {
2206     // Slow path call has full side-effects.
2207     set_predefined_output_for_runtime_call(call);
2208   } else {
2209     // Slow path call has few side-effects, and/or sets few values.
2210     set_predefined_output_for_runtime_call(call, prev_mem, adr_type);
2211   }
2212 
2213   if (has_io) {
2214     set_i_o(_gvn.transform(new (C) ProjNode(call, TypeFunc::I_O)));
2215   }
2216   return call;
2217 
2218 }
2219 
2220 //------------------------------merge_memory-----------------------------------
2221 // Merge memory from one path into the current memory state.
2222 void GraphKit::merge_memory(Node* new_mem, Node* region, int new_path) {
2223   for (MergeMemStream mms(merged_memory(), new_mem->as_MergeMem()); mms.next_non_empty2(); ) {
2224     Node* old_slice = mms.force_memory();
2225     Node* new_slice = mms.memory2();
2226     if (old_slice != new_slice) {
2227       PhiNode* phi;
2228       if (new_slice->is_Phi() && new_slice->as_Phi()->region() == region) {
2229         phi = new_slice->as_Phi();
2230         #ifdef ASSERT
2231         if (old_slice->is_Phi() && old_slice->as_Phi()->region() == region)
2232           old_slice = old_slice->in(new_path);
2233         // Caller is responsible for ensuring that any pre-existing
2234         // phis are already aware of old memory.
2235         int old_path = (new_path > 1) ? 1 : 2;  // choose old_path != new_path
2236         assert(phi->in(old_path) == old_slice, "pre-existing phis OK");
2237         #endif
2238         mms.set_memory(phi);
2239       } else {
2240         phi = PhiNode::make(region, old_slice, Type::MEMORY, mms.adr_type(C));
2241         _gvn.set_type(phi, Type::MEMORY);
2242         phi->set_req(new_path, new_slice);
2243         mms.set_memory(_gvn.transform(phi));  // assume it is complete
2244       }
2245     }
2246   }
2247 }
2248 
2249 //------------------------------make_slow_call_ex------------------------------
2250 // Make the exception handler hookups for the slow call
2251 void GraphKit::make_slow_call_ex(Node* call, ciInstanceKlass* ex_klass, bool separate_io_proj) {
2252   if (stopped())  return;
2253 
2254   // Make a catch node with just two handlers:  fall-through and catch-all
2255   Node* i_o  = _gvn.transform( new (C) ProjNode(call, TypeFunc::I_O, separate_io_proj) );
2256   Node* catc = _gvn.transform( new (C) CatchNode(control(), i_o, 2) );
2257   Node* norm = _gvn.transform( new (C) CatchProjNode(catc, CatchProjNode::fall_through_index, CatchProjNode::no_handler_bci) );
2258   Node* excp = _gvn.transform( new (C) CatchProjNode(catc, CatchProjNode::catch_all_index,    CatchProjNode::no_handler_bci) );
2259 
2260   { PreserveJVMState pjvms(this);
2261     set_control(excp);
2262     set_i_o(i_o);
2263 
2264     if (excp != top()) {
2265       // Create an exception state also.
2266       // Use an exact type if the caller has specified a specific exception.
2267       const Type* ex_type = TypeOopPtr::make_from_klass_unique(ex_klass)->cast_to_ptr_type(TypePtr::NotNull);
2268       Node*       ex_oop  = new (C) CreateExNode(ex_type, control(), i_o);
2269       add_exception_state(make_exception_state(_gvn.transform(ex_oop)));
2270     }
2271   }
2272 
2273   // Get the no-exception control from the CatchNode.
2274   set_control(norm);
2275 }
2276 
2277 
2278 //-------------------------------gen_subtype_check-----------------------------
2279 // Generate a subtyping check.  Takes as input the subtype and supertype.
2280 // Returns 2 values: sets the default control() to the true path and returns
2281 // the false path.  Only reads invariant memory; sets no (visible) memory.
2282 // The PartialSubtypeCheckNode sets the hidden 1-word cache in the encoding
2283 // but that's not exposed to the optimizer.  This call also doesn't take in an
2284 // Object; if you wish to check an Object you need to load the Object's class
2285 // prior to coming here.
2286 Node* GraphKit::gen_subtype_check(Node* subklass, Node* superklass) {
2287   // Fast check for identical types, perhaps identical constants.
2288   // The types can even be identical non-constants, in cases
2289   // involving Array.newInstance, Object.clone, etc.
2290   if (subklass == superklass)
2291     return top();             // false path is dead; no test needed.
2292 
2293   if (_gvn.type(superklass)->singleton()) {
2294     ciKlass* superk = _gvn.type(superklass)->is_klassptr()->klass();
2295     ciKlass* subk   = _gvn.type(subklass)->is_klassptr()->klass();
2296 
2297     // In the common case of an exact superklass, try to fold up the
2298     // test before generating code.  You may ask, why not just generate
2299     // the code and then let it fold up?  The answer is that the generated
2300     // code will necessarily include null checks, which do not always
2301     // completely fold away.  If they are also needless, then they turn
2302     // into a performance loss.  Example:
2303     //    Foo[] fa = blah(); Foo x = fa[0]; fa[1] = x;
2304     // Here, the type of 'fa' is often exact, so the store check
2305     // of fa[1]=x will fold up, without testing the nullness of x.
2306     switch (static_subtype_check(superk, subk)) {
2307     case SSC_always_false:
2308       {
2309         Node* always_fail = control();
2310         set_control(top());
2311         return always_fail;
2312       }
2313     case SSC_always_true:
2314       return top();
2315     case SSC_easy_test:
2316       {
2317         // Just do a direct pointer compare and be done.
2318         Node* cmp = _gvn.transform( new(C) CmpPNode(subklass, superklass) );
2319         Node* bol = _gvn.transform( new(C) BoolNode(cmp, BoolTest::eq) );
2320         IfNode* iff = create_and_xform_if(control(), bol, PROB_STATIC_FREQUENT, COUNT_UNKNOWN);
2321         set_control( _gvn.transform( new(C) IfTrueNode (iff) ) );
2322         return       _gvn.transform( new(C) IfFalseNode(iff) );
2323       }
2324     case SSC_full_test:
2325       break;
2326     default:
2327       ShouldNotReachHere();
2328     }
2329   }
2330 
2331   // %%% Possible further optimization:  Even if the superklass is not exact,
2332   // if the subklass is the unique subtype of the superklass, the check
2333   // will always succeed.  We could leave a dependency behind to ensure this.
2334 
2335   // First load the super-klass's check-offset
2336   Node *p1 = basic_plus_adr( superklass, superklass, in_bytes(Klass::super_check_offset_offset()) );
2337   Node *chk_off = _gvn.transform( new (C) LoadINode( NULL, memory(p1), p1, _gvn.type(p1)->is_ptr() ) );
2338   int cacheoff_con = in_bytes(Klass::secondary_super_cache_offset());
2339   bool might_be_cache = (find_int_con(chk_off, cacheoff_con) == cacheoff_con);
2340 
2341   // Load from the sub-klass's super-class display list, or a 1-word cache of
2342   // the secondary superclass list, or a failing value with a sentinel offset
2343   // if the super-klass is an interface or exceptionally deep in the Java
2344   // hierarchy and we have to scan the secondary superclass list the hard way.
2345   // Worst-case type is a little odd: NULL is allowed as a result (usually
2346   // klass loads can never produce a NULL).
2347   Node *chk_off_X = ConvI2X(chk_off);
2348   Node *p2 = _gvn.transform( new (C) AddPNode(subklass,subklass,chk_off_X) );
2349   // For some types like interfaces the following loadKlass is from a 1-word
2350   // cache which is mutable so can't use immutable memory.  Other
2351   // types load from the super-class display table which is immutable.
2352   Node *kmem = might_be_cache ? memory(p2) : immutable_memory();
2353   Node *nkls = _gvn.transform( LoadKlassNode::make( _gvn, kmem, p2, _gvn.type(p2)->is_ptr(), TypeKlassPtr::OBJECT_OR_NULL ) );
2354 
2355   // Compile speed common case: ARE a subtype and we canNOT fail
2356   if( superklass == nkls )
2357     return top();             // false path is dead; no test needed.
2358 
2359   // See if we get an immediate positive hit.  Happens roughly 83% of the
2360   // time.  Test to see if the value loaded just previously from the subklass
2361   // is exactly the superklass.
2362   Node *cmp1 = _gvn.transform( new (C) CmpPNode( superklass, nkls ) );
2363   Node *bol1 = _gvn.transform( new (C) BoolNode( cmp1, BoolTest::eq ) );
2364   IfNode *iff1 = create_and_xform_if( control(), bol1, PROB_LIKELY(0.83f), COUNT_UNKNOWN );
2365   Node *iftrue1 = _gvn.transform( new (C) IfTrueNode ( iff1 ) );
2366   set_control(    _gvn.transform( new (C) IfFalseNode( iff1 ) ) );
2367 
2368   // Compile speed common case: Check for being deterministic right now.  If
2369   // chk_off is a constant and not equal to cacheoff then we are NOT a
2370   // subklass.  In this case we need exactly the 1 test above and we can
2371   // return those results immediately.
2372   if (!might_be_cache) {
2373     Node* not_subtype_ctrl = control();
2374     set_control(iftrue1); // We need exactly the 1 test above
2375     return not_subtype_ctrl;
2376   }
2377 
2378   // Gather the various success & failures here
2379   RegionNode *r_ok_subtype = new (C) RegionNode(4);
2380   record_for_igvn(r_ok_subtype);
2381   RegionNode *r_not_subtype = new (C) RegionNode(3);
2382   record_for_igvn(r_not_subtype);
2383 
2384   r_ok_subtype->init_req(1, iftrue1);
2385 
2386   // Check for immediate negative hit.  Happens roughly 11% of the time (which
2387   // is roughly 63% of the remaining cases).  Test to see if the loaded
2388   // check-offset points into the subklass display list or the 1-element
2389   // cache.  If it points to the display (and NOT the cache) and the display
2390   // missed then it's not a subtype.
2391   Node *cacheoff = _gvn.intcon(cacheoff_con);
2392   Node *cmp2 = _gvn.transform( new (C) CmpINode( chk_off, cacheoff ) );
2393   Node *bol2 = _gvn.transform( new (C) BoolNode( cmp2, BoolTest::ne ) );
2394   IfNode *iff2 = create_and_xform_if( control(), bol2, PROB_LIKELY(0.63f), COUNT_UNKNOWN );
2395   r_not_subtype->init_req(1, _gvn.transform( new (C) IfTrueNode (iff2) ) );
2396   set_control(                _gvn.transform( new (C) IfFalseNode(iff2) ) );
2397 
2398   // Check for self.  Very rare to get here, but it is taken 1/3 the time.
2399   // No performance impact (too rare) but allows sharing of secondary arrays
2400   // which has some footprint reduction.
2401   Node *cmp3 = _gvn.transform( new (C) CmpPNode( subklass, superklass ) );
2402   Node *bol3 = _gvn.transform( new (C) BoolNode( cmp3, BoolTest::eq ) );
2403   IfNode *iff3 = create_and_xform_if( control(), bol3, PROB_LIKELY(0.36f), COUNT_UNKNOWN );
2404   r_ok_subtype->init_req(2, _gvn.transform( new (C) IfTrueNode ( iff3 ) ) );
2405   set_control(               _gvn.transform( new (C) IfFalseNode( iff3 ) ) );
2406 
2407   // -- Roads not taken here: --
2408   // We could also have chosen to perform the self-check at the beginning
2409   // of this code sequence, as the assembler does.  This would not pay off
2410   // the same way, since the optimizer, unlike the assembler, can perform
2411   // static type analysis to fold away many successful self-checks.
2412   // Non-foldable self checks work better here in second position, because
2413   // the initial primary superclass check subsumes a self-check for most
2414   // types.  An exception would be a secondary type like array-of-interface,
2415   // which does not appear in its own primary supertype display.
2416   // Finally, we could have chosen to move the self-check into the
2417   // PartialSubtypeCheckNode, and from there out-of-line in a platform
2418   // dependent manner.  But it is worthwhile to have the check here,
2419   // where it can be perhaps be optimized.  The cost in code space is
2420   // small (register compare, branch).
2421 
2422   // Now do a linear scan of the secondary super-klass array.  Again, no real
2423   // performance impact (too rare) but it's gotta be done.
2424   // Since the code is rarely used, there is no penalty for moving it
2425   // out of line, and it can only improve I-cache density.
2426   // The decision to inline or out-of-line this final check is platform
2427   // dependent, and is found in the AD file definition of PartialSubtypeCheck.
2428   Node* psc = _gvn.transform(
2429     new (C) PartialSubtypeCheckNode(control(), subklass, superklass) );
2430 
2431   Node *cmp4 = _gvn.transform( new (C) CmpPNode( psc, null() ) );
2432   Node *bol4 = _gvn.transform( new (C) BoolNode( cmp4, BoolTest::ne ) );
2433   IfNode *iff4 = create_and_xform_if( control(), bol4, PROB_FAIR, COUNT_UNKNOWN );
2434   r_not_subtype->init_req(2, _gvn.transform( new (C) IfTrueNode (iff4) ) );
2435   r_ok_subtype ->init_req(3, _gvn.transform( new (C) IfFalseNode(iff4) ) );
2436 
2437   // Return false path; set default control to true path.
2438   set_control( _gvn.transform(r_ok_subtype) );
2439   return _gvn.transform(r_not_subtype);
2440 }
2441 
2442 //----------------------------static_subtype_check-----------------------------
2443 // Shortcut important common cases when superklass is exact:
2444 // (0) superklass is java.lang.Object (can occur in reflective code)
2445 // (1) subklass is already limited to a subtype of superklass => always ok
2446 // (2) subklass does not overlap with superklass => always fail
2447 // (3) superklass has NO subtypes and we can check with a simple compare.
2448 int GraphKit::static_subtype_check(ciKlass* superk, ciKlass* subk) {
2449   if (StressReflectiveCode) {
2450     return SSC_full_test;       // Let caller generate the general case.
2451   }
2452 
2453   if (superk == env()->Object_klass()) {
2454     return SSC_always_true;     // (0) this test cannot fail
2455   }
2456 
2457   ciType* superelem = superk;
2458   if (superelem->is_array_klass())
2459     superelem = superelem->as_array_klass()->base_element_type();
2460 
2461   if (!subk->is_interface()) {  // cannot trust static interface types yet
2462     if (subk->is_subtype_of(superk)) {
2463       return SSC_always_true;   // (1) false path dead; no dynamic test needed
2464     }
2465     if (!(superelem->is_klass() && superelem->as_klass()->is_interface()) &&
2466         !superk->is_subtype_of(subk)) {
2467       return SSC_always_false;
2468     }
2469   }
2470 
2471   // If casting to an instance klass, it must have no subtypes
2472   if (superk->is_interface()) {
2473     // Cannot trust interfaces yet.
2474     // %%% S.B. superk->nof_implementors() == 1
2475   } else if (superelem->is_instance_klass()) {
2476     ciInstanceKlass* ik = superelem->as_instance_klass();
2477     if (!ik->has_subklass() && !ik->is_interface()) {
2478       if (!ik->is_final()) {
2479         // Add a dependency if there is a chance of a later subclass.
2480         C->dependencies()->assert_leaf_type(ik);
2481       }
2482       return SSC_easy_test;     // (3) caller can do a simple ptr comparison
2483     }
2484   } else {
2485     // A primitive array type has no subtypes.
2486     return SSC_easy_test;       // (3) caller can do a simple ptr comparison
2487   }
2488 
2489   return SSC_full_test;
2490 }
2491 
2492 // Profile-driven exact type check:
2493 Node* GraphKit::type_check_receiver(Node* receiver, ciKlass* klass,
2494                                     float prob,
2495                                     Node* *casted_receiver) {
2496   const TypeKlassPtr* tklass = TypeKlassPtr::make(klass);
2497   Node* recv_klass = load_object_klass(receiver);
2498   Node* want_klass = makecon(tklass);
2499   Node* cmp = _gvn.transform( new(C) CmpPNode(recv_klass, want_klass) );
2500   Node* bol = _gvn.transform( new(C) BoolNode(cmp, BoolTest::eq) );
2501   IfNode* iff = create_and_xform_if(control(), bol, prob, COUNT_UNKNOWN);
2502   set_control( _gvn.transform( new(C) IfTrueNode (iff) ));
2503   Node* fail = _gvn.transform( new(C) IfFalseNode(iff) );
2504 
2505   const TypeOopPtr* recv_xtype = tklass->as_instance_type();
2506   assert(recv_xtype->klass_is_exact(), "");
2507 
2508   // Subsume downstream occurrences of receiver with a cast to
2509   // recv_xtype, since now we know what the type will be.
2510   Node* cast = new(C) CheckCastPPNode(control(), receiver, recv_xtype);
2511   (*casted_receiver) = _gvn.transform(cast);
2512   // (User must make the replace_in_map call.)
2513 
2514   return fail;
2515 }
2516 
2517 
2518 //------------------------------seems_never_null-------------------------------
2519 // Use null_seen information if it is available from the profile.
2520 // If we see an unexpected null at a type check we record it and force a
2521 // recompile; the offending check will be recompiled to handle NULLs.
2522 // If we see several offending BCIs, then all checks in the
2523 // method will be recompiled.
2524 bool GraphKit::seems_never_null(Node* obj, ciProfileData* data) {
2525   if (UncommonNullCast               // Cutout for this technique
2526       && obj != null()               // And not the -Xcomp stupid case?
2527       && !too_many_traps(Deoptimization::Reason_null_check)
2528       ) {
2529     if (data == NULL)
2530       // Edge case:  no mature data.  Be optimistic here.
2531       return true;
2532     // If the profile has not seen a null, assume it won't happen.
2533     assert(java_bc() == Bytecodes::_checkcast ||
2534            java_bc() == Bytecodes::_instanceof ||
2535            java_bc() == Bytecodes::_aastore, "MDO must collect null_seen bit here");
2536     return !data->as_BitData()->null_seen();
2537   }
2538   return false;
2539 }
2540 
2541 //------------------------maybe_cast_profiled_receiver-------------------------
2542 // If the profile has seen exactly one type, narrow to exactly that type.
2543 // Subsequent type checks will always fold up.
2544 Node* GraphKit::maybe_cast_profiled_receiver(Node* not_null_obj,
2545                                              ciProfileData* data,
2546                                              ciKlass* require_klass) {
2547   if (!UseTypeProfile || !TypeProfileCasts) return NULL;
2548   if (data == NULL)  return NULL;
2549 
2550   // Make sure we haven't already deoptimized from this tactic.
2551   if (too_many_traps(Deoptimization::Reason_class_check))
2552     return NULL;
2553 
2554   // (No, this isn't a call, but it's enough like a virtual call
2555   // to use the same ciMethod accessor to get the profile info...)
2556   ciCallProfile profile = method()->call_profile_at_bci(bci());
2557   if (profile.count() >= 0 &&         // no cast failures here
2558       profile.has_receiver(0) &&
2559       profile.morphism() == 1) {
2560     ciKlass* exact_kls = profile.receiver(0);
2561     if (require_klass == NULL ||
2562         static_subtype_check(require_klass, exact_kls) == SSC_always_true) {
2563       // If we narrow the type to match what the type profile sees,
2564       // we can then remove the rest of the cast.
2565       // This is a win, even if the exact_kls is very specific,
2566       // because downstream operations, such as method calls,
2567       // will often benefit from the sharper type.
2568       Node* exact_obj = not_null_obj; // will get updated in place...
2569       Node* slow_ctl  = type_check_receiver(exact_obj, exact_kls, 1.0,
2570                                             &exact_obj);
2571       { PreserveJVMState pjvms(this);
2572         set_control(slow_ctl);
2573         uncommon_trap(Deoptimization::Reason_class_check,
2574                       Deoptimization::Action_maybe_recompile);
2575       }
2576       replace_in_map(not_null_obj, exact_obj);
2577       return exact_obj;
2578     }
2579     // assert(ssc == SSC_always_true)... except maybe the profile lied to us.
2580   }
2581 
2582   return NULL;
2583 }
2584 
2585 
2586 //-------------------------------gen_instanceof--------------------------------
2587 // Generate an instance-of idiom.  Used by both the instance-of bytecode
2588 // and the reflective instance-of call.
2589 Node* GraphKit::gen_instanceof(Node* obj, Node* superklass) {
2590   kill_dead_locals();           // Benefit all the uncommon traps
2591   assert( !stopped(), "dead parse path should be checked in callers" );
2592   assert(!TypePtr::NULL_PTR->higher_equal(_gvn.type(superklass)->is_klassptr()),
2593          "must check for not-null not-dead klass in callers");
2594 
2595   // Make the merge point
2596   enum { _obj_path = 1, _fail_path, _null_path, PATH_LIMIT };
2597   RegionNode* region = new(C) RegionNode(PATH_LIMIT);
2598   Node*       phi    = new(C) PhiNode(region, TypeInt::BOOL);
2599   C->set_has_split_ifs(true); // Has chance for split-if optimization
2600 
2601   ciProfileData* data = NULL;
2602   if (java_bc() == Bytecodes::_instanceof) {  // Only for the bytecode
2603     data = method()->method_data()->bci_to_data(bci());
2604   }
2605   bool never_see_null = (ProfileDynamicTypes  // aggressive use of profile
2606                          && seems_never_null(obj, data));
2607 
2608   // Null check; get casted pointer; set region slot 3
2609   Node* null_ctl = top();
2610   Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null);
2611 
2612   // If not_null_obj is dead, only null-path is taken
2613   if (stopped()) {              // Doing instance-of on a NULL?
2614     set_control(null_ctl);
2615     return intcon(0);
2616   }
2617   region->init_req(_null_path, null_ctl);
2618   phi   ->init_req(_null_path, intcon(0)); // Set null path value
2619   if (null_ctl == top()) {
2620     // Do this eagerly, so that pattern matches like is_diamond_phi
2621     // will work even during parsing.
2622     assert(_null_path == PATH_LIMIT-1, "delete last");
2623     region->del_req(_null_path);
2624     phi   ->del_req(_null_path);
2625   }
2626 
2627   if (ProfileDynamicTypes && data != NULL) {
2628     Node* cast_obj = maybe_cast_profiled_receiver(not_null_obj, data, NULL);
2629     if (stopped()) {            // Profile disagrees with this path.
2630       set_control(null_ctl);    // Null is the only remaining possibility.
2631       return intcon(0);
2632     }
2633     if (cast_obj != NULL)
2634       not_null_obj = cast_obj;
2635   }
2636 
2637   // Load the object's klass
2638   Node* obj_klass = load_object_klass(not_null_obj);
2639 
2640   // Generate the subtype check
2641   Node* not_subtype_ctrl = gen_subtype_check(obj_klass, superklass);
2642 
2643   // Plug in the success path to the general merge in slot 1.
2644   region->init_req(_obj_path, control());
2645   phi   ->init_req(_obj_path, intcon(1));
2646 
2647   // Plug in the failing path to the general merge in slot 2.
2648   region->init_req(_fail_path, not_subtype_ctrl);
2649   phi   ->init_req(_fail_path, intcon(0));
2650 
2651   // Return final merged results
2652   set_control( _gvn.transform(region) );
2653   record_for_igvn(region);
2654   return _gvn.transform(phi);
2655 }
2656 
2657 //-------------------------------gen_checkcast---------------------------------
2658 // Generate a checkcast idiom.  Used by both the checkcast bytecode and the
2659 // array store bytecode.  Stack must be as-if BEFORE doing the bytecode so the
2660 // uncommon-trap paths work.  Adjust stack after this call.
2661 // If failure_control is supplied and not null, it is filled in with
2662 // the control edge for the cast failure.  Otherwise, an appropriate
2663 // uncommon trap or exception is thrown.
2664 Node* GraphKit::gen_checkcast(Node *obj, Node* superklass,
2665                               Node* *failure_control) {
2666   kill_dead_locals();           // Benefit all the uncommon traps
2667   const TypeKlassPtr *tk = _gvn.type(superklass)->is_klassptr();
2668   const Type *toop = TypeOopPtr::make_from_klass(tk->klass());
2669 
2670   // Fast cutout:  Check the case that the cast is vacuously true.
2671   // This detects the common cases where the test will short-circuit
2672   // away completely.  We do this before we perform the null check,
2673   // because if the test is going to turn into zero code, we don't
2674   // want a residual null check left around.  (Causes a slowdown,
2675   // for example, in some objArray manipulations, such as a[i]=a[j].)
2676   if (tk->singleton()) {
2677     const TypeOopPtr* objtp = _gvn.type(obj)->isa_oopptr();
2678     if (objtp != NULL && objtp->klass() != NULL) {
2679       switch (static_subtype_check(tk->klass(), objtp->klass())) {
2680       case SSC_always_true:
2681         return obj;
2682       case SSC_always_false:
2683         // It needs a null check because a null will *pass* the cast check.
2684         // A non-null value will always produce an exception.
2685         return null_assert(obj);
2686       }
2687     }
2688   }
2689 
2690   ciProfileData* data = NULL;
2691   if (failure_control == NULL) {        // use MDO in regular case only
2692     assert(java_bc() == Bytecodes::_aastore ||
2693            java_bc() == Bytecodes::_checkcast,
2694            "interpreter profiles type checks only for these BCs");
2695     data = method()->method_data()->bci_to_data(bci());
2696   }
2697 
2698   // Make the merge point
2699   enum { _obj_path = 1, _null_path, PATH_LIMIT };
2700   RegionNode* region = new (C) RegionNode(PATH_LIMIT);
2701   Node*       phi    = new (C) PhiNode(region, toop);
2702   C->set_has_split_ifs(true); // Has chance for split-if optimization
2703 
2704   // Use null-cast information if it is available
2705   bool never_see_null = ((failure_control == NULL)  // regular case only
2706                          && seems_never_null(obj, data));
2707 
2708   // Null check; get casted pointer; set region slot 3
2709   Node* null_ctl = top();
2710   Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null);
2711 
2712   // If not_null_obj is dead, only null-path is taken
2713   if (stopped()) {              // Doing instance-of on a NULL?
2714     set_control(null_ctl);
2715     return null();
2716   }
2717   region->init_req(_null_path, null_ctl);
2718   phi   ->init_req(_null_path, null());  // Set null path value
2719   if (null_ctl == top()) {
2720     // Do this eagerly, so that pattern matches like is_diamond_phi
2721     // will work even during parsing.
2722     assert(_null_path == PATH_LIMIT-1, "delete last");
2723     region->del_req(_null_path);
2724     phi   ->del_req(_null_path);
2725   }
2726 
2727   Node* cast_obj = NULL;
2728   if (data != NULL &&
2729       // Counter has never been decremented (due to cast failure).
2730       // ...This is a reasonable thing to expect.  It is true of
2731       // all casts inserted by javac to implement generic types.
2732       data->as_CounterData()->count() >= 0) {
2733     cast_obj = maybe_cast_profiled_receiver(not_null_obj, data, tk->klass());
2734     if (cast_obj != NULL) {
2735       if (failure_control != NULL) // failure is now impossible
2736         (*failure_control) = top();
2737       // adjust the type of the phi to the exact klass:
2738       phi->raise_bottom_type(_gvn.type(cast_obj)->meet(TypePtr::NULL_PTR));
2739     }
2740   }
2741 
2742   if (cast_obj == NULL) {
2743     // Load the object's klass
2744     Node* obj_klass = load_object_klass(not_null_obj);
2745 
2746     // Generate the subtype check
2747     Node* not_subtype_ctrl = gen_subtype_check( obj_klass, superklass );
2748 
2749     // Plug in success path into the merge
2750     cast_obj = _gvn.transform(new (C) CheckCastPPNode(control(),
2751                                                          not_null_obj, toop));
2752     // Failure path ends in uncommon trap (or may be dead - failure impossible)
2753     if (failure_control == NULL) {
2754       if (not_subtype_ctrl != top()) { // If failure is possible
2755         PreserveJVMState pjvms(this);
2756         set_control(not_subtype_ctrl);
2757         builtin_throw(Deoptimization::Reason_class_check, obj_klass);
2758       }
2759     } else {
2760       (*failure_control) = not_subtype_ctrl;
2761     }
2762   }
2763 
2764   region->init_req(_obj_path, control());
2765   phi   ->init_req(_obj_path, cast_obj);
2766 
2767   // A merge of NULL or Casted-NotNull obj
2768   Node* res = _gvn.transform(phi);
2769 
2770   // Note I do NOT always 'replace_in_map(obj,result)' here.
2771   //  if( tk->klass()->can_be_primary_super()  )
2772     // This means that if I successfully store an Object into an array-of-String
2773     // I 'forget' that the Object is really now known to be a String.  I have to
2774     // do this because we don't have true union types for interfaces - if I store
2775     // a Baz into an array-of-Interface and then tell the optimizer it's an
2776     // Interface, I forget that it's also a Baz and cannot do Baz-like field
2777     // references to it.  FIX THIS WHEN UNION TYPES APPEAR!
2778   //  replace_in_map( obj, res );
2779 
2780   // Return final merged results
2781   set_control( _gvn.transform(region) );
2782   record_for_igvn(region);
2783   return res;
2784 }
2785 
2786 //------------------------------next_monitor-----------------------------------
2787 // What number should be given to the next monitor?
2788 int GraphKit::next_monitor() {
2789   int current = jvms()->monitor_depth()* C->sync_stack_slots();
2790   int next = current + C->sync_stack_slots();
2791   // Keep the toplevel high water mark current:
2792   if (C->fixed_slots() < next)  C->set_fixed_slots(next);
2793   return current;
2794 }
2795 
2796 //------------------------------insert_mem_bar---------------------------------
2797 // Memory barrier to avoid floating things around
2798 // The membar serves as a pinch point between both control and all memory slices.
2799 Node* GraphKit::insert_mem_bar(int opcode, Node* precedent) {
2800   MemBarNode* mb = MemBarNode::make(C, opcode, Compile::AliasIdxBot, precedent);
2801   mb->init_req(TypeFunc::Control, control());
2802   mb->init_req(TypeFunc::Memory,  reset_memory());
2803   Node* membar = _gvn.transform(mb);
2804   set_control(_gvn.transform(new (C) ProjNode(membar, TypeFunc::Control)));
2805   set_all_memory_call(membar);
2806   return membar;
2807 }
2808 
2809 //-------------------------insert_mem_bar_volatile----------------------------
2810 // Memory barrier to avoid floating things around
2811 // The membar serves as a pinch point between both control and memory(alias_idx).
2812 // If you want to make a pinch point on all memory slices, do not use this
2813 // function (even with AliasIdxBot); use insert_mem_bar() instead.
2814 Node* GraphKit::insert_mem_bar_volatile(int opcode, int alias_idx, Node* precedent) {
2815   // When Parse::do_put_xxx updates a volatile field, it appends a series
2816   // of MemBarVolatile nodes, one for *each* volatile field alias category.
2817   // The first membar is on the same memory slice as the field store opcode.
2818   // This forces the membar to follow the store.  (Bug 6500685 broke this.)
2819   // All the other membars (for other volatile slices, including AliasIdxBot,
2820   // which stands for all unknown volatile slices) are control-dependent
2821   // on the first membar.  This prevents later volatile loads or stores
2822   // from sliding up past the just-emitted store.
2823 
2824   MemBarNode* mb = MemBarNode::make(C, opcode, alias_idx, precedent);
2825   mb->set_req(TypeFunc::Control,control());
2826   if (alias_idx == Compile::AliasIdxBot) {
2827     mb->set_req(TypeFunc::Memory, merged_memory()->base_memory());
2828   } else {
2829     assert(!(opcode == Op_Initialize && alias_idx != Compile::AliasIdxRaw), "fix caller");
2830     mb->set_req(TypeFunc::Memory, memory(alias_idx));
2831   }
2832   Node* membar = _gvn.transform(mb);
2833   set_control(_gvn.transform(new (C) ProjNode(membar, TypeFunc::Control)));
2834   if (alias_idx == Compile::AliasIdxBot) {
2835     merged_memory()->set_base_memory(_gvn.transform(new (C) ProjNode(membar, TypeFunc::Memory)));
2836   } else {
2837     set_memory(_gvn.transform(new (C) ProjNode(membar, TypeFunc::Memory)),alias_idx);
2838   }
2839   return membar;
2840 }
2841 
2842 //------------------------------shared_lock------------------------------------
2843 // Emit locking code.
2844 FastLockNode* GraphKit::shared_lock(Node* obj) {
2845   // bci is either a monitorenter bc or InvocationEntryBci
2846   // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
2847   assert(SynchronizationEntryBCI == InvocationEntryBci, "");
2848 
2849   if( !GenerateSynchronizationCode )
2850     return NULL;                // Not locking things?
2851   if (stopped())                // Dead monitor?
2852     return NULL;
2853 
2854   assert(dead_locals_are_killed(), "should kill locals before sync. point");
2855 
2856   // Box the stack location
2857   Node* box = _gvn.transform(new (C) BoxLockNode(next_monitor()));
2858   Node* mem = reset_memory();
2859 
2860   FastLockNode * flock = _gvn.transform(new (C) FastLockNode(0, obj, box) )->as_FastLock();
2861   if (PrintPreciseBiasedLockingStatistics) {
2862     // Create the counters for this fast lock.
2863     flock->create_lock_counter(sync_jvms()); // sync_jvms used to get current bci
2864   }
2865   // Add monitor to debug info for the slow path.  If we block inside the
2866   // slow path and de-opt, we need the monitor hanging around
2867   map()->push_monitor( flock );
2868 
2869   const TypeFunc *tf = LockNode::lock_type();
2870   LockNode *lock = new (C) LockNode(C, tf);
2871 
2872   lock->init_req( TypeFunc::Control, control() );
2873   lock->init_req( TypeFunc::Memory , mem );
2874   lock->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
2875   lock->init_req( TypeFunc::FramePtr, frameptr() );
2876   lock->init_req( TypeFunc::ReturnAdr, top() );
2877 
2878   lock->init_req(TypeFunc::Parms + 0, obj);
2879   lock->init_req(TypeFunc::Parms + 1, box);
2880   lock->init_req(TypeFunc::Parms + 2, flock);
2881   add_safepoint_edges(lock);
2882 
2883   lock = _gvn.transform( lock )->as_Lock();
2884 
2885   // lock has no side-effects, sets few values
2886   set_predefined_output_for_runtime_call(lock, mem, TypeRawPtr::BOTTOM);
2887 
2888   insert_mem_bar(Op_MemBarAcquireLock);
2889 
2890   // Add this to the worklist so that the lock can be eliminated
2891   record_for_igvn(lock);
2892 
2893 #ifndef PRODUCT
2894   if (PrintLockStatistics) {
2895     // Update the counter for this lock.  Don't bother using an atomic
2896     // operation since we don't require absolute accuracy.
2897     lock->create_lock_counter(map()->jvms());
2898     increment_counter(lock->counter()->addr());
2899   }
2900 #endif
2901 
2902   return flock;
2903 }
2904 
2905 
2906 //------------------------------shared_unlock----------------------------------
2907 // Emit unlocking code.
2908 void GraphKit::shared_unlock(Node* box, Node* obj) {
2909   // bci is either a monitorenter bc or InvocationEntryBci
2910   // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
2911   assert(SynchronizationEntryBCI == InvocationEntryBci, "");
2912 
2913   if( !GenerateSynchronizationCode )
2914     return;
2915   if (stopped()) {               // Dead monitor?
2916     map()->pop_monitor();        // Kill monitor from debug info
2917     return;
2918   }
2919 
2920   // Memory barrier to avoid floating things down past the locked region
2921   insert_mem_bar(Op_MemBarReleaseLock);
2922 
2923   const TypeFunc *tf = OptoRuntime::complete_monitor_exit_Type();
2924   UnlockNode *unlock = new (C) UnlockNode(C, tf);
2925   uint raw_idx = Compile::AliasIdxRaw;
2926   unlock->init_req( TypeFunc::Control, control() );
2927   unlock->init_req( TypeFunc::Memory , memory(raw_idx) );
2928   unlock->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
2929   unlock->init_req( TypeFunc::FramePtr, frameptr() );
2930   unlock->init_req( TypeFunc::ReturnAdr, top() );
2931 
2932   unlock->init_req(TypeFunc::Parms + 0, obj);
2933   unlock->init_req(TypeFunc::Parms + 1, box);
2934   unlock = _gvn.transform(unlock)->as_Unlock();
2935 
2936   Node* mem = reset_memory();
2937 
2938   // unlock has no side-effects, sets few values
2939   set_predefined_output_for_runtime_call(unlock, mem, TypeRawPtr::BOTTOM);
2940 
2941   // Kill monitor from debug info
2942   map()->pop_monitor( );
2943 }
2944 
2945 //-------------------------------get_layout_helper-----------------------------
2946 // If the given klass is a constant or known to be an array,
2947 // fetch the constant layout helper value into constant_value
2948 // and return (Node*)NULL.  Otherwise, load the non-constant
2949 // layout helper value, and return the node which represents it.
2950 // This two-faced routine is useful because allocation sites
2951 // almost always feature constant types.
2952 Node* GraphKit::get_layout_helper(Node* klass_node, jint& constant_value) {
2953   const TypeKlassPtr* inst_klass = _gvn.type(klass_node)->isa_klassptr();
2954   if (!StressReflectiveCode && inst_klass != NULL) {
2955     ciKlass* klass = inst_klass->klass();
2956     bool    xklass = inst_klass->klass_is_exact();
2957     if (xklass || klass->is_array_klass()) {
2958       jint lhelper = klass->layout_helper();
2959       if (lhelper != Klass::_lh_neutral_value) {
2960         constant_value = lhelper;
2961         return (Node*) NULL;
2962       }
2963     }
2964   }
2965   constant_value = Klass::_lh_neutral_value;  // put in a known value
2966   Node* lhp = basic_plus_adr(klass_node, klass_node, in_bytes(Klass::layout_helper_offset()));
2967   return make_load(NULL, lhp, TypeInt::INT, T_INT);
2968 }
2969 
2970 // We just put in an allocate/initialize with a big raw-memory effect.
2971 // Hook selected additional alias categories on the initialization.
2972 static void hook_memory_on_init(GraphKit& kit, int alias_idx,
2973                                 MergeMemNode* init_in_merge,
2974                                 Node* init_out_raw) {
2975   DEBUG_ONLY(Node* init_in_raw = init_in_merge->base_memory());
2976   assert(init_in_merge->memory_at(alias_idx) == init_in_raw, "");
2977 
2978   Node* prevmem = kit.memory(alias_idx);
2979   init_in_merge->set_memory_at(alias_idx, prevmem);
2980   kit.set_memory(init_out_raw, alias_idx);
2981 }
2982 
2983 //---------------------------set_output_for_allocation-------------------------
2984 Node* GraphKit::set_output_for_allocation(AllocateNode* alloc,
2985                                           const TypeOopPtr* oop_type) {
2986   int rawidx = Compile::AliasIdxRaw;
2987   alloc->set_req( TypeFunc::FramePtr, frameptr() );
2988   add_safepoint_edges(alloc);
2989   Node* allocx = _gvn.transform(alloc);
2990   set_control( _gvn.transform(new (C) ProjNode(allocx, TypeFunc::Control) ) );
2991   // create memory projection for i_o
2992   set_memory ( _gvn.transform( new (C) ProjNode(allocx, TypeFunc::Memory, true) ), rawidx );
2993   make_slow_call_ex(allocx, env()->OutOfMemoryError_klass(), true);
2994 
2995   // create a memory projection as for the normal control path
2996   Node* malloc = _gvn.transform(new (C) ProjNode(allocx, TypeFunc::Memory));
2997   set_memory(malloc, rawidx);
2998 
2999   // a normal slow-call doesn't change i_o, but an allocation does
3000   // we create a separate i_o projection for the normal control path
3001   set_i_o(_gvn.transform( new (C) ProjNode(allocx, TypeFunc::I_O, false) ) );
3002   Node* rawoop = _gvn.transform( new (C) ProjNode(allocx, TypeFunc::Parms) );
3003 
3004   // put in an initialization barrier
3005   InitializeNode* init = insert_mem_bar_volatile(Op_Initialize, rawidx,
3006                                                  rawoop)->as_Initialize();
3007   assert(alloc->initialization() == init,  "2-way macro link must work");
3008   assert(init ->allocation()     == alloc, "2-way macro link must work");
3009   {
3010     // Extract memory strands which may participate in the new object's
3011     // initialization, and source them from the new InitializeNode.
3012     // This will allow us to observe initializations when they occur,
3013     // and link them properly (as a group) to the InitializeNode.
3014     assert(init->in(InitializeNode::Memory) == malloc, "");
3015     MergeMemNode* minit_in = MergeMemNode::make(C, malloc);
3016     init->set_req(InitializeNode::Memory, minit_in);
3017     record_for_igvn(minit_in); // fold it up later, if possible
3018     Node* minit_out = memory(rawidx);
3019     assert(minit_out->is_Proj() && minit_out->in(0) == init, "");
3020     if (oop_type->isa_aryptr()) {
3021       const TypePtr* telemref = oop_type->add_offset(Type::OffsetBot);
3022       int            elemidx  = C->get_alias_index(telemref);
3023       hook_memory_on_init(*this, elemidx, minit_in, minit_out);
3024     } else if (oop_type->isa_instptr()) {
3025       ciInstanceKlass* ik = oop_type->klass()->as_instance_klass();
3026       for (int i = 0, len = ik->nof_nonstatic_fields(); i < len; i++) {
3027         ciField* field = ik->nonstatic_field_at(i);
3028         if (field->offset() >= TrackedInitializationLimit * HeapWordSize)
3029           continue;  // do not bother to track really large numbers of fields
3030         // Find (or create) the alias category for this field:
3031         int fieldidx = C->alias_type(field)->index();
3032         hook_memory_on_init(*this, fieldidx, minit_in, minit_out);
3033       }
3034     }
3035   }
3036 
3037   // Cast raw oop to the real thing...
3038   Node* javaoop = new (C) CheckCastPPNode(control(), rawoop, oop_type);
3039   javaoop = _gvn.transform(javaoop);
3040   C->set_recent_alloc(control(), javaoop);
3041   assert(just_allocated_object(control()) == javaoop, "just allocated");
3042 
3043 #ifdef ASSERT
3044   { // Verify that the AllocateNode::Ideal_allocation recognizers work:
3045     assert(AllocateNode::Ideal_allocation(rawoop, &_gvn) == alloc,
3046            "Ideal_allocation works");
3047     assert(AllocateNode::Ideal_allocation(javaoop, &_gvn) == alloc,
3048            "Ideal_allocation works");
3049     if (alloc->is_AllocateArray()) {
3050       assert(AllocateArrayNode::Ideal_array_allocation(rawoop, &_gvn) == alloc->as_AllocateArray(),
3051              "Ideal_allocation works");
3052       assert(AllocateArrayNode::Ideal_array_allocation(javaoop, &_gvn) == alloc->as_AllocateArray(),
3053              "Ideal_allocation works");
3054     } else {
3055       assert(alloc->in(AllocateNode::ALength)->is_top(), "no length, please");
3056     }
3057   }
3058 #endif //ASSERT
3059 
3060   return javaoop;
3061 }
3062 
3063 //---------------------------new_instance--------------------------------------
3064 // This routine takes a klass_node which may be constant (for a static type)
3065 // or may be non-constant (for reflective code).  It will work equally well
3066 // for either, and the graph will fold nicely if the optimizer later reduces
3067 // the type to a constant.
3068 // The optional arguments are for specialized use by intrinsics:
3069 //  - If 'extra_slow_test' if not null is an extra condition for the slow-path.
3070 //  - If 'return_size_val', report the the total object size to the caller.
3071 Node* GraphKit::new_instance(Node* klass_node,
3072                              Node* extra_slow_test,
3073                              Node* *return_size_val) {
3074   // Compute size in doublewords
3075   // The size is always an integral number of doublewords, represented
3076   // as a positive bytewise size stored in the klass's layout_helper.
3077   // The layout_helper also encodes (in a low bit) the need for a slow path.
3078   jint  layout_con = Klass::_lh_neutral_value;
3079   Node* layout_val = get_layout_helper(klass_node, layout_con);
3080   int   layout_is_con = (layout_val == NULL);
3081 
3082   if (extra_slow_test == NULL)  extra_slow_test = intcon(0);
3083   // Generate the initial go-slow test.  It's either ALWAYS (return a
3084   // Node for 1) or NEVER (return a NULL) or perhaps (in the reflective
3085   // case) a computed value derived from the layout_helper.
3086   Node* initial_slow_test = NULL;
3087   if (layout_is_con) {
3088     assert(!StressReflectiveCode, "stress mode does not use these paths");
3089     bool must_go_slow = Klass::layout_helper_needs_slow_path(layout_con);
3090     initial_slow_test = must_go_slow? intcon(1): extra_slow_test;
3091 
3092   } else {   // reflective case
3093     // This reflective path is used by Unsafe.allocateInstance.
3094     // (It may be stress-tested by specifying StressReflectiveCode.)
3095     // Basically, we want to get into the VM is there's an illegal argument.
3096     Node* bit = intcon(Klass::_lh_instance_slow_path_bit);
3097     initial_slow_test = _gvn.transform( new (C) AndINode(layout_val, bit) );
3098     if (extra_slow_test != intcon(0)) {
3099       initial_slow_test = _gvn.transform( new (C) OrINode(initial_slow_test, extra_slow_test) );
3100     }
3101     // (Macro-expander will further convert this to a Bool, if necessary.)
3102   }
3103 
3104   // Find the size in bytes.  This is easy; it's the layout_helper.
3105   // The size value must be valid even if the slow path is taken.
3106   Node* size = NULL;
3107   if (layout_is_con) {
3108     size = MakeConX(Klass::layout_helper_size_in_bytes(layout_con));
3109   } else {   // reflective case
3110     // This reflective path is used by clone and Unsafe.allocateInstance.
3111     size = ConvI2X(layout_val);
3112 
3113     // Clear the low bits to extract layout_helper_size_in_bytes:
3114     assert((int)Klass::_lh_instance_slow_path_bit < BytesPerLong, "clear bit");
3115     Node* mask = MakeConX(~ (intptr_t)right_n_bits(LogBytesPerLong));
3116     size = _gvn.transform( new (C) AndXNode(size, mask) );
3117   }
3118   if (return_size_val != NULL) {
3119     (*return_size_val) = size;
3120   }
3121 
3122   // This is a precise notnull oop of the klass.
3123   // (Actually, it need not be precise if this is a reflective allocation.)
3124   // It's what we cast the result to.
3125   const TypeKlassPtr* tklass = _gvn.type(klass_node)->isa_klassptr();
3126   if (!tklass)  tklass = TypeKlassPtr::OBJECT;
3127   const TypeOopPtr* oop_type = tklass->as_instance_type();
3128 
3129   // Now generate allocation code
3130 
3131   // The entire memory state is needed for slow path of the allocation
3132   // since GC and deoptimization can happened.
3133   Node *mem = reset_memory();
3134   set_all_memory(mem); // Create new memory state
3135 
3136   AllocateNode* alloc
3137     = new (C) AllocateNode(C, AllocateNode::alloc_type(),
3138                            control(), mem, i_o(),
3139                            size, klass_node,
3140                            initial_slow_test);
3141 
3142   return set_output_for_allocation(alloc, oop_type);
3143 }
3144 
3145 //-------------------------------new_array-------------------------------------
3146 // helper for both newarray and anewarray
3147 // The 'length' parameter is (obviously) the length of the array.
3148 // See comments on new_instance for the meaning of the other arguments.
3149 Node* GraphKit::new_array(Node* klass_node,     // array klass (maybe variable)
3150                           Node* length,         // number of array elements
3151                           int   nargs,          // number of arguments to push back for uncommon trap
3152                           Node* *return_size_val) {
3153   jint  layout_con = Klass::_lh_neutral_value;
3154   Node* layout_val = get_layout_helper(klass_node, layout_con);
3155   int   layout_is_con = (layout_val == NULL);
3156 
3157   if (!layout_is_con && !StressReflectiveCode &&
3158       !too_many_traps(Deoptimization::Reason_class_check)) {
3159     // This is a reflective array creation site.
3160     // Optimistically assume that it is a subtype of Object[],
3161     // so that we can fold up all the address arithmetic.
3162     layout_con = Klass::array_layout_helper(T_OBJECT);
3163     Node* cmp_lh = _gvn.transform( new(C) CmpINode(layout_val, intcon(layout_con)) );
3164     Node* bol_lh = _gvn.transform( new(C) BoolNode(cmp_lh, BoolTest::eq) );
3165     { BuildCutout unless(this, bol_lh, PROB_MAX);
3166       inc_sp(nargs);
3167       uncommon_trap(Deoptimization::Reason_class_check,
3168                     Deoptimization::Action_maybe_recompile);
3169     }
3170     layout_val = NULL;
3171     layout_is_con = true;
3172   }
3173 
3174   // Generate the initial go-slow test.  Make sure we do not overflow
3175   // if length is huge (near 2Gig) or negative!  We do not need
3176   // exact double-words here, just a close approximation of needed
3177   // double-words.  We can't add any offset or rounding bits, lest we
3178   // take a size -1 of bytes and make it positive.  Use an unsigned
3179   // compare, so negative sizes look hugely positive.
3180   int fast_size_limit = FastAllocateSizeLimit;
3181   if (layout_is_con) {
3182     assert(!StressReflectiveCode, "stress mode does not use these paths");
3183     // Increase the size limit if we have exact knowledge of array type.
3184     int log2_esize = Klass::layout_helper_log2_element_size(layout_con);
3185     fast_size_limit <<= (LogBytesPerLong - log2_esize);
3186   }
3187 
3188   Node* initial_slow_cmp  = _gvn.transform( new (C) CmpUNode( length, intcon( fast_size_limit ) ) );
3189   Node* initial_slow_test = _gvn.transform( new (C) BoolNode( initial_slow_cmp, BoolTest::gt ) );
3190   if (initial_slow_test->is_Bool()) {
3191     // Hide it behind a CMoveI, or else PhaseIdealLoop::split_up will get sick.
3192     initial_slow_test = initial_slow_test->as_Bool()->as_int_value(&_gvn);
3193   }
3194 
3195   // --- Size Computation ---
3196   // array_size = round_to_heap(array_header + (length << elem_shift));
3197   // where round_to_heap(x) == round_to(x, MinObjAlignmentInBytes)
3198   // and round_to(x, y) == ((x + y-1) & ~(y-1))
3199   // The rounding mask is strength-reduced, if possible.
3200   int round_mask = MinObjAlignmentInBytes - 1;
3201   Node* header_size = NULL;
3202   int   header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
3203   // (T_BYTE has the weakest alignment and size restrictions...)
3204   if (layout_is_con) {
3205     int       hsize  = Klass::layout_helper_header_size(layout_con);
3206     int       eshift = Klass::layout_helper_log2_element_size(layout_con);
3207     BasicType etype  = Klass::layout_helper_element_type(layout_con);
3208     if ((round_mask & ~right_n_bits(eshift)) == 0)
3209       round_mask = 0;  // strength-reduce it if it goes away completely
3210     assert((hsize & right_n_bits(eshift)) == 0, "hsize is pre-rounded");
3211     assert(header_size_min <= hsize, "generic minimum is smallest");
3212     header_size_min = hsize;
3213     header_size = intcon(hsize + round_mask);
3214   } else {
3215     Node* hss   = intcon(Klass::_lh_header_size_shift);
3216     Node* hsm   = intcon(Klass::_lh_header_size_mask);
3217     Node* hsize = _gvn.transform( new(C) URShiftINode(layout_val, hss) );
3218     hsize       = _gvn.transform( new(C) AndINode(hsize, hsm) );
3219     Node* mask  = intcon(round_mask);
3220     header_size = _gvn.transform( new(C) AddINode(hsize, mask) );
3221   }
3222 
3223   Node* elem_shift = NULL;
3224   if (layout_is_con) {
3225     int eshift = Klass::layout_helper_log2_element_size(layout_con);
3226     if (eshift != 0)
3227       elem_shift = intcon(eshift);
3228   } else {
3229     // There is no need to mask or shift this value.
3230     // The semantics of LShiftINode include an implicit mask to 0x1F.
3231     assert(Klass::_lh_log2_element_size_shift == 0, "use shift in place");
3232     elem_shift = layout_val;
3233   }
3234 
3235   // Transition to native address size for all offset calculations:
3236   Node* lengthx = ConvI2X(length);
3237   Node* headerx = ConvI2X(header_size);
3238 #ifdef _LP64
3239   { const TypeLong* tllen = _gvn.find_long_type(lengthx);
3240     if (tllen != NULL && tllen->_lo < 0) {
3241       // Add a manual constraint to a positive range.  Cf. array_element_address.
3242       jlong size_max = arrayOopDesc::max_array_length(T_BYTE);
3243       if (size_max > tllen->_hi)  size_max = tllen->_hi;
3244       const TypeLong* tlcon = TypeLong::make(CONST64(0), size_max, Type::WidenMin);
3245       lengthx = _gvn.transform( new (C) ConvI2LNode(length, tlcon));
3246     }
3247   }
3248 #endif
3249 
3250   // Combine header size (plus rounding) and body size.  Then round down.
3251   // This computation cannot overflow, because it is used only in two
3252   // places, one where the length is sharply limited, and the other
3253   // after a successful allocation.
3254   Node* abody = lengthx;
3255   if (elem_shift != NULL)
3256     abody     = _gvn.transform( new(C) LShiftXNode(lengthx, elem_shift) );
3257   Node* size  = _gvn.transform( new(C) AddXNode(headerx, abody) );
3258   if (round_mask != 0) {
3259     Node* mask = MakeConX(~round_mask);
3260     size       = _gvn.transform( new(C) AndXNode(size, mask) );
3261   }
3262   // else if round_mask == 0, the size computation is self-rounding
3263 
3264   if (return_size_val != NULL) {
3265     // This is the size
3266     (*return_size_val) = size;
3267   }
3268 
3269   // Now generate allocation code
3270 
3271   // The entire memory state is needed for slow path of the allocation
3272   // since GC and deoptimization can happened.
3273   Node *mem = reset_memory();
3274   set_all_memory(mem); // Create new memory state
3275 
3276   // Create the AllocateArrayNode and its result projections
3277   AllocateArrayNode* alloc
3278     = new (C) AllocateArrayNode(C, AllocateArrayNode::alloc_type(),
3279                                 control(), mem, i_o(),
3280                                 size, klass_node,
3281                                 initial_slow_test,
3282                                 length);
3283 
3284   // Cast to correct type.  Note that the klass_node may be constant or not,
3285   // and in the latter case the actual array type will be inexact also.
3286   // (This happens via a non-constant argument to inline_native_newArray.)
3287   // In any case, the value of klass_node provides the desired array type.
3288   const TypeInt* length_type = _gvn.find_int_type(length);
3289   const TypeOopPtr* ary_type = _gvn.type(klass_node)->is_klassptr()->as_instance_type();
3290   if (ary_type->isa_aryptr() && length_type != NULL) {
3291     // Try to get a better type than POS for the size
3292     ary_type = ary_type->is_aryptr()->cast_to_size(length_type);
3293   }
3294 
3295   Node* javaoop = set_output_for_allocation(alloc, ary_type);
3296 
3297   // Cast length on remaining path to be as narrow as possible
3298   if (map()->find_edge(length) >= 0) {
3299     Node* ccast = alloc->make_ideal_length(ary_type, &_gvn);
3300     if (ccast != length) {
3301       _gvn.set_type_bottom(ccast);
3302       record_for_igvn(ccast);
3303       replace_in_map(length, ccast);
3304     }
3305   }
3306 
3307   return javaoop;
3308 }
3309 
3310 // The following "Ideal_foo" functions are placed here because they recognize
3311 // the graph shapes created by the functions immediately above.
3312 
3313 //---------------------------Ideal_allocation----------------------------------
3314 // Given an oop pointer or raw pointer, see if it feeds from an AllocateNode.
3315 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase) {
3316   if (ptr == NULL) {     // reduce dumb test in callers
3317     return NULL;
3318   }
3319   if (ptr->is_CheckCastPP()) {  // strip a raw-to-oop cast
3320     ptr = ptr->in(1);
3321     if (ptr == NULL)  return NULL;
3322   }
3323   if (ptr->is_Proj()) {
3324     Node* allo = ptr->in(0);
3325     if (allo != NULL && allo->is_Allocate()) {
3326       return allo->as_Allocate();
3327     }
3328   }
3329   // Report failure to match.
3330   return NULL;
3331 }
3332 
3333 // Fancy version which also strips off an offset (and reports it to caller).
3334 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase,
3335                                              intptr_t& offset) {
3336   Node* base = AddPNode::Ideal_base_and_offset(ptr, phase, offset);
3337   if (base == NULL)  return NULL;
3338   return Ideal_allocation(base, phase);
3339 }
3340 
3341 // Trace Initialize <- Proj[Parm] <- Allocate
3342 AllocateNode* InitializeNode::allocation() {
3343   Node* rawoop = in(InitializeNode::RawAddress);
3344   if (rawoop->is_Proj()) {
3345     Node* alloc = rawoop->in(0);
3346     if (alloc->is_Allocate()) {
3347       return alloc->as_Allocate();
3348     }
3349   }
3350   return NULL;
3351 }
3352 
3353 // Trace Allocate -> Proj[Parm] -> Initialize
3354 InitializeNode* AllocateNode::initialization() {
3355   ProjNode* rawoop = proj_out(AllocateNode::RawAddress);
3356   if (rawoop == NULL)  return NULL;
3357   for (DUIterator_Fast imax, i = rawoop->fast_outs(imax); i < imax; i++) {
3358     Node* init = rawoop->fast_out(i);
3359     if (init->is_Initialize()) {
3360       assert(init->as_Initialize()->allocation() == this, "2-way link");
3361       return init->as_Initialize();
3362     }
3363   }
3364   return NULL;
3365 }
3366 
3367 // Trace Allocate -> Proj[Parm] -> MemBarStoreStore
3368 MemBarStoreStoreNode* AllocateNode::storestore() {
3369   ProjNode* rawoop = proj_out(AllocateNode::RawAddress);
3370   if (rawoop == NULL)  return NULL;
3371   for (DUIterator_Fast imax, i = rawoop->fast_outs(imax); i < imax; i++) {
3372     Node* storestore = rawoop->fast_out(i);
3373     if (storestore->is_MemBarStoreStore()) {
3374       return storestore->as_MemBarStoreStore();
3375     }
3376   }
3377   return NULL;
3378 }
3379 
3380 //----------------------------- loop predicates ---------------------------
3381 
3382 //------------------------------add_predicate_impl----------------------------
3383 void GraphKit::add_predicate_impl(Deoptimization::DeoptReason reason, int nargs) {
3384   // Too many traps seen?
3385   if (too_many_traps(reason)) {
3386 #ifdef ASSERT
3387     if (TraceLoopPredicate) {
3388       int tc = C->trap_count(reason);
3389       tty->print("too many traps=%s tcount=%d in ",
3390                     Deoptimization::trap_reason_name(reason), tc);
3391       method()->print(); // which method has too many predicate traps
3392       tty->cr();
3393     }
3394 #endif
3395     // We cannot afford to take more traps here,
3396     // do not generate predicate.
3397     return;
3398   }
3399 
3400   Node *cont    = _gvn.intcon(1);
3401   Node* opq     = _gvn.transform(new (C) Opaque1Node(C, cont));
3402   Node *bol     = _gvn.transform(new (C) Conv2BNode(opq));
3403   IfNode* iff   = create_and_map_if(control(), bol, PROB_MAX, COUNT_UNKNOWN);
3404   Node* iffalse = _gvn.transform(new (C) IfFalseNode(iff));
3405   C->add_predicate_opaq(opq);
3406   {
3407     PreserveJVMState pjvms(this);
3408     set_control(iffalse);
3409     inc_sp(nargs);
3410     uncommon_trap(reason, Deoptimization::Action_maybe_recompile);
3411   }
3412   Node* iftrue = _gvn.transform(new (C) IfTrueNode(iff));
3413   set_control(iftrue);
3414 }
3415 
3416 //------------------------------add_predicate---------------------------------
3417 void GraphKit::add_predicate(int nargs) {
3418   if (UseLoopPredicate) {
3419     add_predicate_impl(Deoptimization::Reason_predicate, nargs);
3420   }
3421   // loop's limit check predicate should be near the loop.
3422   if (LoopLimitCheck) {
3423     add_predicate_impl(Deoptimization::Reason_loop_limit_check, nargs);
3424   }
3425 }
3426 
3427 //----------------------------- store barriers ----------------------------
3428 #define __ ideal.
3429 
3430 void GraphKit::sync_kit(IdealKit& ideal) {
3431   set_all_memory(__ merged_memory());
3432   set_i_o(__ i_o());
3433   set_control(__ ctrl());
3434 }
3435 
3436 void GraphKit::final_sync(IdealKit& ideal) {
3437   // Final sync IdealKit and graphKit.
3438   __ drain_delay_transform();
3439   sync_kit(ideal);
3440 }
3441 
3442 // vanilla/CMS post barrier
3443 // Insert a write-barrier store.  This is to let generational GC work; we have
3444 // to flag all oop-stores before the next GC point.
3445 void GraphKit::write_barrier_post(Node* oop_store,
3446                                   Node* obj,
3447                                   Node* adr,
3448                                   uint  adr_idx,
3449                                   Node* val,
3450                                   bool use_precise) {
3451   // No store check needed if we're storing a NULL or an old object
3452   // (latter case is probably a string constant). The concurrent
3453   // mark sweep garbage collector, however, needs to have all nonNull
3454   // oop updates flagged via card-marks.
3455   if (val != NULL && val->is_Con()) {
3456     // must be either an oop or NULL
3457     const Type* t = val->bottom_type();
3458     if (t == TypePtr::NULL_PTR || t == Type::TOP)
3459       // stores of null never (?) need barriers
3460       return;
3461   }
3462 
3463   if (use_ReduceInitialCardMarks()
3464       && obj == just_allocated_object(control())) {
3465     // We can skip marks on a freshly-allocated object in Eden.
3466     // Keep this code in sync with new_store_pre_barrier() in runtime.cpp.
3467     // That routine informs GC to take appropriate compensating steps,
3468     // upon a slow-path allocation, so as to make this card-mark
3469     // elision safe.
3470     return;
3471   }
3472 
3473   if (!use_precise) {
3474     // All card marks for a (non-array) instance are in one place:
3475     adr = obj;
3476   }
3477   // (Else it's an array (or unknown), and we want more precise card marks.)
3478   assert(adr != NULL, "");
3479 
3480   IdealKit ideal(this, true);
3481 
3482   // Convert the pointer to an int prior to doing math on it
3483   Node* cast = __ CastPX(__ ctrl(), adr);
3484 
3485   // Divide by card size
3486   assert(Universe::heap()->barrier_set()->kind() == BarrierSet::CardTableModRef,
3487          "Only one we handle so far.");
3488   Node* card_offset = __ URShiftX( cast, __ ConI(CardTableModRefBS::card_shift) );
3489 
3490   // Combine card table base and card offset
3491   Node* card_adr = __ AddP(__ top(), byte_map_base_node(), card_offset );
3492 
3493   // Get the alias_index for raw card-mark memory
3494   int adr_type = Compile::AliasIdxRaw;
3495   Node*   zero = __ ConI(0); // Dirty card value
3496   BasicType bt = T_BYTE;
3497 
3498   if (UseCondCardMark) {
3499     // The classic GC reference write barrier is typically implemented
3500     // as a store into the global card mark table.  Unfortunately
3501     // unconditional stores can result in false sharing and excessive
3502     // coherence traffic as well as false transactional aborts.
3503     // UseCondCardMark enables MP "polite" conditional card mark
3504     // stores.  In theory we could relax the load from ctrl() to
3505     // no_ctrl, but that doesn't buy much latitude.
3506     Node* card_val = __ load( __ ctrl(), card_adr, TypeInt::BYTE, bt, adr_type);
3507     __ if_then(card_val, BoolTest::ne, zero);
3508   }
3509 
3510   // Smash zero into card
3511   if( !UseConcMarkSweepGC ) {
3512     __ store(__ ctrl(), card_adr, zero, bt, adr_type);
3513   } else {
3514     // Specialized path for CM store barrier
3515     __ storeCM(__ ctrl(), card_adr, zero, oop_store, adr_idx, bt, adr_type);
3516   }
3517 
3518   if (UseCondCardMark) {
3519     __ end_if();
3520   }
3521 
3522   // Final sync IdealKit and GraphKit.
3523   final_sync(ideal);
3524 }
3525 
3526 // G1 pre/post barriers
3527 void GraphKit::g1_write_barrier_pre(bool do_load,
3528                                     Node* obj,
3529                                     Node* adr,
3530                                     uint alias_idx,
3531                                     Node* val,
3532                                     const TypeOopPtr* val_type,
3533                                     Node* pre_val,
3534                                     BasicType bt) {
3535 
3536   // Some sanity checks
3537   // Note: val is unused in this routine.
3538 
3539   if (do_load) {
3540     // We need to generate the load of the previous value
3541     assert(obj != NULL, "must have a base");
3542     assert(adr != NULL, "where are loading from?");
3543     assert(pre_val == NULL, "loaded already?");
3544     assert(val_type != NULL, "need a type");
3545   } else {
3546     // In this case both val_type and alias_idx are unused.
3547     assert(pre_val != NULL, "must be loaded already");
3548     assert(pre_val->bottom_type()->basic_type() == T_OBJECT, "or we shouldn't be here");
3549   }
3550   assert(bt == T_OBJECT, "or we shouldn't be here");
3551 
3552   IdealKit ideal(this, true);
3553 
3554   Node* tls = __ thread(); // ThreadLocalStorage
3555 
3556   Node* no_ctrl = NULL;
3557   Node* no_base = __ top();
3558   Node* zero = __ ConI(0);
3559 
3560   float likely  = PROB_LIKELY(0.999);
3561   float unlikely  = PROB_UNLIKELY(0.999);
3562 
3563   BasicType active_type = in_bytes(PtrQueue::byte_width_of_active()) == 4 ? T_INT : T_BYTE;
3564   assert(in_bytes(PtrQueue::byte_width_of_active()) == 4 || in_bytes(PtrQueue::byte_width_of_active()) == 1, "flag width");
3565 
3566   // Offsets into the thread
3567   const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() +  // 648
3568                                           PtrQueue::byte_offset_of_active());
3569   const int index_offset   = in_bytes(JavaThread::satb_mark_queue_offset() +  // 656
3570                                           PtrQueue::byte_offset_of_index());
3571   const int buffer_offset  = in_bytes(JavaThread::satb_mark_queue_offset() +  // 652
3572                                           PtrQueue::byte_offset_of_buf());
3573 
3574   // Now the actual pointers into the thread
3575   Node* marking_adr = __ AddP(no_base, tls, __ ConX(marking_offset));
3576   Node* buffer_adr  = __ AddP(no_base, tls, __ ConX(buffer_offset));
3577   Node* index_adr   = __ AddP(no_base, tls, __ ConX(index_offset));
3578 
3579   // Now some of the values
3580   Node* marking = __ load(__ ctrl(), marking_adr, TypeInt::INT, active_type, Compile::AliasIdxRaw);
3581 
3582   // if (!marking)
3583   __ if_then(marking, BoolTest::ne, zero); {
3584     Node* index   = __ load(__ ctrl(), index_adr, TypeInt::INT, T_INT, Compile::AliasIdxRaw);
3585 
3586     if (do_load) {
3587       // load original value
3588       // alias_idx correct??
3589       pre_val = __ load(no_ctrl, adr, val_type, bt, alias_idx);
3590     }
3591 
3592     // if (pre_val != NULL)
3593     __ if_then(pre_val, BoolTest::ne, null()); {
3594       Node* buffer  = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
3595 
3596       // is the queue for this thread full?
3597       __ if_then(index, BoolTest::ne, zero, likely); {
3598 
3599         // decrement the index
3600         Node* next_index = __ SubI(index,  __ ConI(sizeof(intptr_t)));
3601         Node* next_indexX = next_index;
3602 #ifdef _LP64
3603         // We could refine the type for what it's worth
3604         // const TypeLong* lidxtype = TypeLong::make(CONST64(0), get_size_from_queue);
3605         next_indexX = _gvn.transform( new (C) ConvI2LNode(next_index, TypeLong::make(0, max_jlong, Type::WidenMax)) );
3606 #endif
3607 
3608         // Now get the buffer location we will log the previous value into and store it
3609         Node *log_addr = __ AddP(no_base, buffer, next_indexX);
3610         __ store(__ ctrl(), log_addr, pre_val, T_OBJECT, Compile::AliasIdxRaw);
3611         // update the index
3612         __ store(__ ctrl(), index_adr, next_index, T_INT, Compile::AliasIdxRaw);
3613 
3614       } __ else_(); {
3615 
3616         // logging buffer is full, call the runtime
3617         const TypeFunc *tf = OptoRuntime::g1_wb_pre_Type();
3618         __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_pre), "g1_wb_pre", pre_val, tls);
3619       } __ end_if();  // (!index)
3620     } __ end_if();  // (pre_val != NULL)
3621   } __ end_if();  // (!marking)
3622 
3623   // Final sync IdealKit and GraphKit.
3624   final_sync(ideal);
3625 }
3626 
3627 //
3628 // Update the card table and add card address to the queue
3629 //
3630 void GraphKit::g1_mark_card(IdealKit& ideal,
3631                             Node* card_adr,
3632                             Node* oop_store,
3633                             uint oop_alias_idx,
3634                             Node* index,
3635                             Node* index_adr,
3636                             Node* buffer,
3637                             const TypeFunc* tf) {
3638 
3639   Node* zero = __ ConI(0);
3640   Node* no_base = __ top();
3641   BasicType card_bt = T_BYTE;
3642   // Smash zero into card. MUST BE ORDERED WRT TO STORE
3643   __ storeCM(__ ctrl(), card_adr, zero, oop_store, oop_alias_idx, card_bt, Compile::AliasIdxRaw);
3644 
3645   //  Now do the queue work
3646   __ if_then(index, BoolTest::ne, zero); {
3647 
3648     Node* next_index = __ SubI(index, __ ConI(sizeof(intptr_t)));
3649     Node* next_indexX = next_index;
3650 #ifdef _LP64
3651     // We could refine the type for what it's worth
3652     // const TypeLong* lidxtype = TypeLong::make(CONST64(0), get_size_from_queue);
3653     next_indexX = _gvn.transform( new (C) ConvI2LNode(next_index, TypeLong::make(0, max_jlong, Type::WidenMax)) );
3654 #endif // _LP64
3655     Node* log_addr = __ AddP(no_base, buffer, next_indexX);
3656 
3657     __ store(__ ctrl(), log_addr, card_adr, T_ADDRESS, Compile::AliasIdxRaw);
3658     __ store(__ ctrl(), index_adr, next_index, T_INT, Compile::AliasIdxRaw);
3659 
3660   } __ else_(); {
3661     __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_post), "g1_wb_post", card_adr, __ thread());
3662   } __ end_if();
3663 
3664 }
3665 
3666 void GraphKit::g1_write_barrier_post(Node* oop_store,
3667                                      Node* obj,
3668                                      Node* adr,
3669                                      uint alias_idx,
3670                                      Node* val,
3671                                      BasicType bt,
3672                                      bool use_precise) {
3673   // If we are writing a NULL then we need no post barrier
3674 
3675   if (val != NULL && val->is_Con() && val->bottom_type() == TypePtr::NULL_PTR) {
3676     // Must be NULL
3677     const Type* t = val->bottom_type();
3678     assert(t == Type::TOP || t == TypePtr::NULL_PTR, "must be NULL");
3679     // No post barrier if writing NULLx
3680     return;
3681   }
3682 
3683   if (!use_precise) {
3684     // All card marks for a (non-array) instance are in one place:
3685     adr = obj;
3686   }
3687   // (Else it's an array (or unknown), and we want more precise card marks.)
3688   assert(adr != NULL, "");
3689 
3690   IdealKit ideal(this, true);
3691 
3692   Node* tls = __ thread(); // ThreadLocalStorage
3693 
3694   Node* no_base = __ top();
3695   float likely  = PROB_LIKELY(0.999);
3696   float unlikely  = PROB_UNLIKELY(0.999);
3697   Node* zero = __ ConI(0);
3698   Node* zeroX = __ ConX(0);
3699 
3700   // Get the alias_index for raw card-mark memory
3701   const TypePtr* card_type = TypeRawPtr::BOTTOM;
3702 
3703   const TypeFunc *tf = OptoRuntime::g1_wb_post_Type();
3704 
3705   // Offsets into the thread
3706   const int index_offset  = in_bytes(JavaThread::dirty_card_queue_offset() +
3707                                      PtrQueue::byte_offset_of_index());
3708   const int buffer_offset = in_bytes(JavaThread::dirty_card_queue_offset() +
3709                                      PtrQueue::byte_offset_of_buf());
3710 
3711   // Pointers into the thread
3712 
3713   Node* buffer_adr = __ AddP(no_base, tls, __ ConX(buffer_offset));
3714   Node* index_adr =  __ AddP(no_base, tls, __ ConX(index_offset));
3715 
3716   // Now some values
3717   // Use ctrl to avoid hoisting these values past a safepoint, which could
3718   // potentially reset these fields in the JavaThread.
3719   Node* index  = __ load(__ ctrl(), index_adr, TypeInt::INT, T_INT, Compile::AliasIdxRaw);
3720   Node* buffer = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
3721 
3722   // Convert the store obj pointer to an int prior to doing math on it
3723   // Must use ctrl to prevent "integerized oop" existing across safepoint
3724   Node* cast =  __ CastPX(__ ctrl(), adr);
3725 
3726   // Divide pointer by card size
3727   Node* card_offset = __ URShiftX( cast, __ ConI(CardTableModRefBS::card_shift) );
3728 
3729   // Combine card table base and card offset
3730   Node* card_adr = __ AddP(no_base, byte_map_base_node(), card_offset );
3731 
3732   // If we know the value being stored does it cross regions?
3733 
3734   if (val != NULL) {
3735     // Does the store cause us to cross regions?
3736 
3737     // Should be able to do an unsigned compare of region_size instead of
3738     // and extra shift. Do we have an unsigned compare??
3739     // Node* region_size = __ ConI(1 << HeapRegion::LogOfHRGrainBytes);
3740     Node* xor_res =  __ URShiftX ( __ XorX( cast,  __ CastPX(__ ctrl(), val)), __ ConI(HeapRegion::LogOfHRGrainBytes));
3741 
3742     // if (xor_res == 0) same region so skip
3743     __ if_then(xor_res, BoolTest::ne, zeroX); {
3744 
3745       // No barrier if we are storing a NULL
3746       __ if_then(val, BoolTest::ne, null(), unlikely); {
3747 
3748         // Ok must mark the card if not already dirty
3749 
3750         // load the original value of the card
3751         Node* card_val = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
3752 
3753         __ if_then(card_val, BoolTest::ne, zero); {
3754           g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
3755         } __ end_if();
3756       } __ end_if();
3757     } __ end_if();
3758   } else {
3759     // Object.clone() instrinsic uses this path.
3760     g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
3761   }
3762 
3763   // Final sync IdealKit and GraphKit.
3764   final_sync(ideal);
3765 }
3766 #undef __
3767 
3768 
3769 
3770 Node* GraphKit::load_String_offset(Node* ctrl, Node* str) {
3771   if (java_lang_String::has_offset_field()) {
3772     int offset_offset = java_lang_String::offset_offset_in_bytes();
3773     const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
3774                                                        false, NULL, 0);
3775     const TypePtr* offset_field_type = string_type->add_offset(offset_offset);
3776     int offset_field_idx = C->get_alias_index(offset_field_type);
3777     return make_load(ctrl,
3778                      basic_plus_adr(str, str, offset_offset),
3779                      TypeInt::INT, T_INT, offset_field_idx);
3780   } else {
3781     return intcon(0);
3782   }
3783 }
3784 
3785 Node* GraphKit::load_String_length(Node* ctrl, Node* str) {
3786   if (java_lang_String::has_count_field()) {
3787     int count_offset = java_lang_String::count_offset_in_bytes();
3788     const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
3789                                                        false, NULL, 0);
3790     const TypePtr* count_field_type = string_type->add_offset(count_offset);
3791     int count_field_idx = C->get_alias_index(count_field_type);
3792     return make_load(ctrl,
3793                      basic_plus_adr(str, str, count_offset),
3794                      TypeInt::INT, T_INT, count_field_idx);
3795   } else {
3796     return load_array_length(load_String_value(ctrl, str));
3797   }
3798 }
3799 
3800 Node* GraphKit::load_String_value(Node* ctrl, Node* str) {
3801   int value_offset = java_lang_String::value_offset_in_bytes();
3802   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
3803                                                      false, NULL, 0);
3804   const TypePtr* value_field_type = string_type->add_offset(value_offset);
3805   const TypeAryPtr*  value_type = TypeAryPtr::make(TypePtr::NotNull,
3806                                                    TypeAry::make(TypeInt::CHAR,TypeInt::POS),
3807                                                    ciTypeArrayKlass::make(T_CHAR), true, 0);
3808   int value_field_idx = C->get_alias_index(value_field_type);
3809   return make_load(ctrl, basic_plus_adr(str, str, value_offset),
3810                    value_type, T_OBJECT, value_field_idx);
3811 }
3812 
3813 void GraphKit::store_String_offset(Node* ctrl, Node* str, Node* value) {
3814   int offset_offset = java_lang_String::offset_offset_in_bytes();
3815   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
3816                                                      false, NULL, 0);
3817   const TypePtr* offset_field_type = string_type->add_offset(offset_offset);
3818   int offset_field_idx = C->get_alias_index(offset_field_type);
3819   store_to_memory(ctrl, basic_plus_adr(str, offset_offset),
3820                   value, T_INT, offset_field_idx);
3821 }
3822 
3823 void GraphKit::store_String_value(Node* ctrl, Node* str, Node* value) {
3824   int value_offset = java_lang_String::value_offset_in_bytes();
3825   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
3826                                                      false, NULL, 0);
3827   const TypePtr* value_field_type = string_type->add_offset(value_offset);
3828   const TypeAryPtr*  value_type = TypeAryPtr::make(TypePtr::NotNull,
3829                                                    TypeAry::make(TypeInt::CHAR,TypeInt::POS),
3830                                                    ciTypeArrayKlass::make(T_CHAR), true, 0);
3831   int value_field_idx = C->get_alias_index(value_field_type);
3832   store_to_memory(ctrl, basic_plus_adr(str, value_offset),
3833                   value, T_OBJECT, value_field_idx);
3834 }
3835 
3836 void GraphKit::store_String_length(Node* ctrl, Node* str, Node* value) {
3837   int count_offset = java_lang_String::count_offset_in_bytes();
3838   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
3839                                                      false, NULL, 0);
3840   const TypePtr* count_field_type = string_type->add_offset(count_offset);
3841   int count_field_idx = C->get_alias_index(count_field_type);
3842   store_to_memory(ctrl, basic_plus_adr(str, count_offset),
3843                   value, T_INT, count_field_idx);
3844 }