1 /*
   2  * Copyright (c) 2001, 2015, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "compiler/compileLog.hpp"
  27 #include "ci/ciValueKlass.hpp"
  28 #include "gc/g1/g1SATBCardTableModRefBS.hpp"
  29 #include "gc/g1/heapRegion.hpp"
  30 #include "gc/shared/barrierSet.hpp"
  31 #include "gc/shared/cardTableModRefBS.hpp"
  32 #include "gc/shared/collectedHeap.hpp"
  33 #include "opto/addnode.hpp"
  34 #include "opto/castnode.hpp"
  35 #include "opto/convertnode.hpp"
  36 #include "opto/graphKit.hpp"
  37 #include "opto/idealKit.hpp"
  38 #include "opto/intrinsicnode.hpp"
  39 #include "opto/locknode.hpp"
  40 #include "opto/machnode.hpp"
  41 #include "opto/opaquenode.hpp"
  42 #include "opto/parse.hpp"
  43 #include "opto/rootnode.hpp"
  44 #include "opto/runtime.hpp"
  45 #include "opto/valuetypenode.hpp"
  46 #include "runtime/deoptimization.hpp"
  47 #include "runtime/sharedRuntime.hpp"
  48 
  49 //----------------------------GraphKit-----------------------------------------
  50 // Main utility constructor.
  51 GraphKit::GraphKit(JVMState* jvms)
  52   : Phase(Phase::Parser),
  53     _env(C->env()),
  54     _gvn(*C->initial_gvn())
  55 {
  56   _exceptions = jvms->map()->next_exception();
  57   if (_exceptions != NULL)  jvms->map()->set_next_exception(NULL);
  58   set_jvms(jvms);
  59 }
  60 
  61 // Private constructor for parser.
  62 GraphKit::GraphKit()
  63   : Phase(Phase::Parser),
  64     _env(C->env()),
  65     _gvn(*C->initial_gvn())
  66 {
  67   _exceptions = NULL;
  68   set_map(NULL);
  69   debug_only(_sp = -99);
  70   debug_only(set_bci(-99));
  71 }
  72 
  73 
  74 
  75 //---------------------------clean_stack---------------------------------------
  76 // Clear away rubbish from the stack area of the JVM state.
  77 // This destroys any arguments that may be waiting on the stack.
  78 void GraphKit::clean_stack(int from_sp) {
  79   SafePointNode* map      = this->map();
  80   JVMState*      jvms     = this->jvms();
  81   int            stk_size = jvms->stk_size();
  82   int            stkoff   = jvms->stkoff();
  83   Node*          top      = this->top();
  84   for (int i = from_sp; i < stk_size; i++) {
  85     if (map->in(stkoff + i) != top) {
  86       map->set_req(stkoff + i, top);
  87     }
  88   }
  89 }
  90 
  91 
  92 //--------------------------------sync_jvms-----------------------------------
  93 // Make sure our current jvms agrees with our parse state.
  94 JVMState* GraphKit::sync_jvms() const {
  95   JVMState* jvms = this->jvms();
  96   jvms->set_bci(bci());       // Record the new bci in the JVMState
  97   jvms->set_sp(sp());         // Record the new sp in the JVMState
  98   assert(jvms_in_sync(), "jvms is now in sync");
  99   return jvms;
 100 }
 101 
 102 //--------------------------------sync_jvms_for_reexecute---------------------
 103 // Make sure our current jvms agrees with our parse state.  This version
 104 // uses the reexecute_sp for reexecuting bytecodes.
 105 JVMState* GraphKit::sync_jvms_for_reexecute() {
 106   JVMState* jvms = this->jvms();
 107   jvms->set_bci(bci());          // Record the new bci in the JVMState
 108   jvms->set_sp(reexecute_sp());  // Record the new sp in the JVMState
 109   return jvms;
 110 }
 111 
 112 #ifdef ASSERT
 113 bool GraphKit::jvms_in_sync() const {
 114   Parse* parse = is_Parse();
 115   if (parse == NULL) {
 116     if (bci() !=      jvms()->bci())          return false;
 117     if (sp()  != (int)jvms()->sp())           return false;
 118     return true;
 119   }
 120   if (jvms()->method() != parse->method())    return false;
 121   if (jvms()->bci()    != parse->bci())       return false;
 122   int jvms_sp = jvms()->sp();
 123   if (jvms_sp          != parse->sp())        return false;
 124   int jvms_depth = jvms()->depth();
 125   if (jvms_depth       != parse->depth())     return false;
 126   return true;
 127 }
 128 
 129 // Local helper checks for special internal merge points
 130 // used to accumulate and merge exception states.
 131 // They are marked by the region's in(0) edge being the map itself.
 132 // Such merge points must never "escape" into the parser at large,
 133 // until they have been handed to gvn.transform.
 134 static bool is_hidden_merge(Node* reg) {
 135   if (reg == NULL)  return false;
 136   if (reg->is_Phi()) {
 137     reg = reg->in(0);
 138     if (reg == NULL)  return false;
 139   }
 140   return reg->is_Region() && reg->in(0) != NULL && reg->in(0)->is_Root();
 141 }
 142 
 143 void GraphKit::verify_map() const {
 144   if (map() == NULL)  return;  // null map is OK
 145   assert(map()->req() <= jvms()->endoff(), "no extra garbage on map");
 146   assert(!map()->has_exceptions(),    "call add_exception_states_from 1st");
 147   assert(!is_hidden_merge(control()), "call use_exception_state, not set_map");
 148 }
 149 
 150 void GraphKit::verify_exception_state(SafePointNode* ex_map) {
 151   assert(ex_map->next_exception() == NULL, "not already part of a chain");
 152   assert(has_saved_ex_oop(ex_map), "every exception state has an ex_oop");
 153 }
 154 #endif
 155 
 156 //---------------------------stop_and_kill_map---------------------------------
 157 // Set _map to NULL, signalling a stop to further bytecode execution.
 158 // First smash the current map's control to a constant, to mark it dead.
 159 void GraphKit::stop_and_kill_map() {
 160   SafePointNode* dead_map = stop();
 161   if (dead_map != NULL) {
 162     dead_map->disconnect_inputs(NULL, C); // Mark the map as killed.
 163     assert(dead_map->is_killed(), "must be so marked");
 164   }
 165 }
 166 
 167 
 168 //--------------------------------stopped--------------------------------------
 169 // Tell if _map is NULL, or control is top.
 170 bool GraphKit::stopped() {
 171   if (map() == NULL)           return true;
 172   else if (control() == top()) return true;
 173   else                         return false;
 174 }
 175 
 176 
 177 //-----------------------------has_ex_handler----------------------------------
 178 // Tell if this method or any caller method has exception handlers.
 179 bool GraphKit::has_ex_handler() {
 180   for (JVMState* jvmsp = jvms(); jvmsp != NULL; jvmsp = jvmsp->caller()) {
 181     if (jvmsp->has_method() && jvmsp->method()->has_exception_handlers()) {
 182       return true;
 183     }
 184   }
 185   return false;
 186 }
 187 
 188 //------------------------------save_ex_oop------------------------------------
 189 // Save an exception without blowing stack contents or other JVM state.
 190 void GraphKit::set_saved_ex_oop(SafePointNode* ex_map, Node* ex_oop) {
 191   assert(!has_saved_ex_oop(ex_map), "clear ex-oop before setting again");
 192   ex_map->add_req(ex_oop);
 193   debug_only(verify_exception_state(ex_map));
 194 }
 195 
 196 inline static Node* common_saved_ex_oop(SafePointNode* ex_map, bool clear_it) {
 197   assert(GraphKit::has_saved_ex_oop(ex_map), "ex_oop must be there");
 198   Node* ex_oop = ex_map->in(ex_map->req()-1);
 199   if (clear_it)  ex_map->del_req(ex_map->req()-1);
 200   return ex_oop;
 201 }
 202 
 203 //-----------------------------saved_ex_oop------------------------------------
 204 // Recover a saved exception from its map.
 205 Node* GraphKit::saved_ex_oop(SafePointNode* ex_map) {
 206   return common_saved_ex_oop(ex_map, false);
 207 }
 208 
 209 //--------------------------clear_saved_ex_oop---------------------------------
 210 // Erase a previously saved exception from its map.
 211 Node* GraphKit::clear_saved_ex_oop(SafePointNode* ex_map) {
 212   return common_saved_ex_oop(ex_map, true);
 213 }
 214 
 215 #ifdef ASSERT
 216 //---------------------------has_saved_ex_oop----------------------------------
 217 // Erase a previously saved exception from its map.
 218 bool GraphKit::has_saved_ex_oop(SafePointNode* ex_map) {
 219   return ex_map->req() == ex_map->jvms()->endoff()+1;
 220 }
 221 #endif
 222 
 223 //-------------------------make_exception_state--------------------------------
 224 // Turn the current JVM state into an exception state, appending the ex_oop.
 225 SafePointNode* GraphKit::make_exception_state(Node* ex_oop) {
 226   sync_jvms();
 227   SafePointNode* ex_map = stop();  // do not manipulate this map any more
 228   set_saved_ex_oop(ex_map, ex_oop);
 229   return ex_map;
 230 }
 231 
 232 
 233 //--------------------------add_exception_state--------------------------------
 234 // Add an exception to my list of exceptions.
 235 void GraphKit::add_exception_state(SafePointNode* ex_map) {
 236   if (ex_map == NULL || ex_map->control() == top()) {
 237     return;
 238   }
 239 #ifdef ASSERT
 240   verify_exception_state(ex_map);
 241   if (has_exceptions()) {
 242     assert(ex_map->jvms()->same_calls_as(_exceptions->jvms()), "all collected exceptions must come from the same place");
 243   }
 244 #endif
 245 
 246   // If there is already an exception of exactly this type, merge with it.
 247   // In particular, null-checks and other low-level exceptions common up here.
 248   Node*       ex_oop  = saved_ex_oop(ex_map);
 249   const Type* ex_type = _gvn.type(ex_oop);
 250   if (ex_oop == top()) {
 251     // No action needed.
 252     return;
 253   }
 254   assert(ex_type->isa_instptr(), "exception must be an instance");
 255   for (SafePointNode* e2 = _exceptions; e2 != NULL; e2 = e2->next_exception()) {
 256     const Type* ex_type2 = _gvn.type(saved_ex_oop(e2));
 257     // We check sp also because call bytecodes can generate exceptions
 258     // both before and after arguments are popped!
 259     if (ex_type2 == ex_type
 260         && e2->_jvms->sp() == ex_map->_jvms->sp()) {
 261       combine_exception_states(ex_map, e2);
 262       return;
 263     }
 264   }
 265 
 266   // No pre-existing exception of the same type.  Chain it on the list.
 267   push_exception_state(ex_map);
 268 }
 269 
 270 //-----------------------add_exception_states_from-----------------------------
 271 void GraphKit::add_exception_states_from(JVMState* jvms) {
 272   SafePointNode* ex_map = jvms->map()->next_exception();
 273   if (ex_map != NULL) {
 274     jvms->map()->set_next_exception(NULL);
 275     for (SafePointNode* next_map; ex_map != NULL; ex_map = next_map) {
 276       next_map = ex_map->next_exception();
 277       ex_map->set_next_exception(NULL);
 278       add_exception_state(ex_map);
 279     }
 280   }
 281 }
 282 
 283 //-----------------------transfer_exceptions_into_jvms-------------------------
 284 JVMState* GraphKit::transfer_exceptions_into_jvms() {
 285   if (map() == NULL) {
 286     // We need a JVMS to carry the exceptions, but the map has gone away.
 287     // Create a scratch JVMS, cloned from any of the exception states...
 288     if (has_exceptions()) {
 289       _map = _exceptions;
 290       _map = clone_map();
 291       _map->set_next_exception(NULL);
 292       clear_saved_ex_oop(_map);
 293       debug_only(verify_map());
 294     } else {
 295       // ...or created from scratch
 296       JVMState* jvms = new (C) JVMState(_method, NULL);
 297       jvms->set_bci(_bci);
 298       jvms->set_sp(_sp);
 299       jvms->set_map(new SafePointNode(TypeFunc::Parms, jvms));
 300       set_jvms(jvms);
 301       for (uint i = 0; i < map()->req(); i++)  map()->init_req(i, top());
 302       set_all_memory(top());
 303       while (map()->req() < jvms->endoff())  map()->add_req(top());
 304     }
 305     // (This is a kludge, in case you didn't notice.)
 306     set_control(top());
 307   }
 308   JVMState* jvms = sync_jvms();
 309   assert(!jvms->map()->has_exceptions(), "no exceptions on this map yet");
 310   jvms->map()->set_next_exception(_exceptions);
 311   _exceptions = NULL;   // done with this set of exceptions
 312   return jvms;
 313 }
 314 
 315 static inline void add_n_reqs(Node* dstphi, Node* srcphi) {
 316   assert(is_hidden_merge(dstphi), "must be a special merge node");
 317   assert(is_hidden_merge(srcphi), "must be a special merge node");
 318   uint limit = srcphi->req();
 319   for (uint i = PhiNode::Input; i < limit; i++) {
 320     dstphi->add_req(srcphi->in(i));
 321   }
 322 }
 323 static inline void add_one_req(Node* dstphi, Node* src) {
 324   assert(is_hidden_merge(dstphi), "must be a special merge node");
 325   assert(!is_hidden_merge(src), "must not be a special merge node");
 326   dstphi->add_req(src);
 327 }
 328 
 329 //-----------------------combine_exception_states------------------------------
 330 // This helper function combines exception states by building phis on a
 331 // specially marked state-merging region.  These regions and phis are
 332 // untransformed, and can build up gradually.  The region is marked by
 333 // having a control input of its exception map, rather than NULL.  Such
 334 // regions do not appear except in this function, and in use_exception_state.
 335 void GraphKit::combine_exception_states(SafePointNode* ex_map, SafePointNode* phi_map) {
 336   if (failing())  return;  // dying anyway...
 337   JVMState* ex_jvms = ex_map->_jvms;
 338   assert(ex_jvms->same_calls_as(phi_map->_jvms), "consistent call chains");
 339   assert(ex_jvms->stkoff() == phi_map->_jvms->stkoff(), "matching locals");
 340   assert(ex_jvms->sp() == phi_map->_jvms->sp(), "matching stack sizes");
 341   assert(ex_jvms->monoff() == phi_map->_jvms->monoff(), "matching JVMS");
 342   assert(ex_jvms->scloff() == phi_map->_jvms->scloff(), "matching scalar replaced objects");
 343   assert(ex_map->req() == phi_map->req(), "matching maps");
 344   uint tos = ex_jvms->stkoff() + ex_jvms->sp();
 345   Node*         hidden_merge_mark = root();
 346   Node*         region  = phi_map->control();
 347   MergeMemNode* phi_mem = phi_map->merged_memory();
 348   MergeMemNode* ex_mem  = ex_map->merged_memory();
 349   if (region->in(0) != hidden_merge_mark) {
 350     // The control input is not (yet) a specially-marked region in phi_map.
 351     // Make it so, and build some phis.
 352     region = new RegionNode(2);
 353     _gvn.set_type(region, Type::CONTROL);
 354     region->set_req(0, hidden_merge_mark);  // marks an internal ex-state
 355     region->init_req(1, phi_map->control());
 356     phi_map->set_control(region);
 357     Node* io_phi = PhiNode::make(region, phi_map->i_o(), Type::ABIO);
 358     record_for_igvn(io_phi);
 359     _gvn.set_type(io_phi, Type::ABIO);
 360     phi_map->set_i_o(io_phi);
 361     for (MergeMemStream mms(phi_mem); mms.next_non_empty(); ) {
 362       Node* m = mms.memory();
 363       Node* m_phi = PhiNode::make(region, m, Type::MEMORY, mms.adr_type(C));
 364       record_for_igvn(m_phi);
 365       _gvn.set_type(m_phi, Type::MEMORY);
 366       mms.set_memory(m_phi);
 367     }
 368   }
 369 
 370   // Either or both of phi_map and ex_map might already be converted into phis.
 371   Node* ex_control = ex_map->control();
 372   // if there is special marking on ex_map also, we add multiple edges from src
 373   bool add_multiple = (ex_control->in(0) == hidden_merge_mark);
 374   // how wide was the destination phi_map, originally?
 375   uint orig_width = region->req();
 376 
 377   if (add_multiple) {
 378     add_n_reqs(region, ex_control);
 379     add_n_reqs(phi_map->i_o(), ex_map->i_o());
 380   } else {
 381     // ex_map has no merges, so we just add single edges everywhere
 382     add_one_req(region, ex_control);
 383     add_one_req(phi_map->i_o(), ex_map->i_o());
 384   }
 385   for (MergeMemStream mms(phi_mem, ex_mem); mms.next_non_empty2(); ) {
 386     if (mms.is_empty()) {
 387       // get a copy of the base memory, and patch some inputs into it
 388       const TypePtr* adr_type = mms.adr_type(C);
 389       Node* phi = mms.force_memory()->as_Phi()->slice_memory(adr_type);
 390       assert(phi->as_Phi()->region() == mms.base_memory()->in(0), "");
 391       mms.set_memory(phi);
 392       // Prepare to append interesting stuff onto the newly sliced phi:
 393       while (phi->req() > orig_width)  phi->del_req(phi->req()-1);
 394     }
 395     // Append stuff from ex_map:
 396     if (add_multiple) {
 397       add_n_reqs(mms.memory(), mms.memory2());
 398     } else {
 399       add_one_req(mms.memory(), mms.memory2());
 400     }
 401   }
 402   uint limit = ex_map->req();
 403   for (uint i = TypeFunc::Parms; i < limit; i++) {
 404     // Skip everything in the JVMS after tos.  (The ex_oop follows.)
 405     if (i == tos)  i = ex_jvms->monoff();
 406     Node* src = ex_map->in(i);
 407     Node* dst = phi_map->in(i);
 408     if (src != dst) {
 409       PhiNode* phi;
 410       if (dst->in(0) != region) {
 411         dst = phi = PhiNode::make(region, dst, _gvn.type(dst));
 412         record_for_igvn(phi);
 413         _gvn.set_type(phi, phi->type());
 414         phi_map->set_req(i, dst);
 415         // Prepare to append interesting stuff onto the new phi:
 416         while (dst->req() > orig_width)  dst->del_req(dst->req()-1);
 417       } else {
 418         assert(dst->is_Phi(), "nobody else uses a hidden region");
 419         phi = dst->as_Phi();
 420       }
 421       if (add_multiple && src->in(0) == ex_control) {
 422         // Both are phis.
 423         add_n_reqs(dst, src);
 424       } else {
 425         while (dst->req() < region->req())  add_one_req(dst, src);
 426       }
 427       const Type* srctype = _gvn.type(src);
 428       if (phi->type() != srctype) {
 429         const Type* dsttype = phi->type()->meet_speculative(srctype);
 430         if (phi->type() != dsttype) {
 431           phi->set_type(dsttype);
 432           _gvn.set_type(phi, dsttype);
 433         }
 434       }
 435     }
 436   }
 437   phi_map->merge_replaced_nodes_with(ex_map);
 438 }
 439 
 440 //--------------------------use_exception_state--------------------------------
 441 Node* GraphKit::use_exception_state(SafePointNode* phi_map) {
 442   if (failing()) { stop(); return top(); }
 443   Node* region = phi_map->control();
 444   Node* hidden_merge_mark = root();
 445   assert(phi_map->jvms()->map() == phi_map, "sanity: 1-1 relation");
 446   Node* ex_oop = clear_saved_ex_oop(phi_map);
 447   if (region->in(0) == hidden_merge_mark) {
 448     // Special marking for internal ex-states.  Process the phis now.
 449     region->set_req(0, region);  // now it's an ordinary region
 450     set_jvms(phi_map->jvms());   // ...so now we can use it as a map
 451     // Note: Setting the jvms also sets the bci and sp.
 452     set_control(_gvn.transform(region));
 453     uint tos = jvms()->stkoff() + sp();
 454     for (uint i = 1; i < tos; i++) {
 455       Node* x = phi_map->in(i);
 456       if (x->in(0) == region) {
 457         assert(x->is_Phi(), "expected a special phi");
 458         phi_map->set_req(i, _gvn.transform(x));
 459       }
 460     }
 461     for (MergeMemStream mms(merged_memory()); mms.next_non_empty(); ) {
 462       Node* x = mms.memory();
 463       if (x->in(0) == region) {
 464         assert(x->is_Phi(), "nobody else uses a hidden region");
 465         mms.set_memory(_gvn.transform(x));
 466       }
 467     }
 468     if (ex_oop->in(0) == region) {
 469       assert(ex_oop->is_Phi(), "expected a special phi");
 470       ex_oop = _gvn.transform(ex_oop);
 471     }
 472   } else {
 473     set_jvms(phi_map->jvms());
 474   }
 475 
 476   assert(!is_hidden_merge(phi_map->control()), "hidden ex. states cleared");
 477   assert(!is_hidden_merge(phi_map->i_o()), "hidden ex. states cleared");
 478   return ex_oop;
 479 }
 480 
 481 //---------------------------------java_bc-------------------------------------
 482 Bytecodes::Code GraphKit::java_bc() const {
 483   ciMethod* method = this->method();
 484   int       bci    = this->bci();
 485   if (method != NULL && bci != InvocationEntryBci)
 486     return method->java_code_at_bci(bci);
 487   else
 488     return Bytecodes::_illegal;
 489 }
 490 
 491 void GraphKit::uncommon_trap_if_should_post_on_exceptions(Deoptimization::DeoptReason reason,
 492                                                           bool must_throw) {
 493     // if the exception capability is set, then we will generate code
 494     // to check the JavaThread.should_post_on_exceptions flag to see
 495     // if we actually need to report exception events (for this
 496     // thread).  If we don't need to report exception events, we will
 497     // take the normal fast path provided by add_exception_events.  If
 498     // exception event reporting is enabled for this thread, we will
 499     // take the uncommon_trap in the BuildCutout below.
 500 
 501     // first must access the should_post_on_exceptions_flag in this thread's JavaThread
 502     Node* jthread = _gvn.transform(new ThreadLocalNode());
 503     Node* adr = basic_plus_adr(top(), jthread, in_bytes(JavaThread::should_post_on_exceptions_flag_offset()));
 504     Node* should_post_flag = make_load(control(), adr, TypeInt::INT, T_INT, Compile::AliasIdxRaw, MemNode::unordered);
 505 
 506     // Test the should_post_on_exceptions_flag vs. 0
 507     Node* chk = _gvn.transform( new CmpINode(should_post_flag, intcon(0)) );
 508     Node* tst = _gvn.transform( new BoolNode(chk, BoolTest::eq) );
 509 
 510     // Branch to slow_path if should_post_on_exceptions_flag was true
 511     { BuildCutout unless(this, tst, PROB_MAX);
 512       // Do not try anything fancy if we're notifying the VM on every throw.
 513       // Cf. case Bytecodes::_athrow in parse2.cpp.
 514       uncommon_trap(reason, Deoptimization::Action_none,
 515                     (ciKlass*)NULL, (char*)NULL, must_throw);
 516     }
 517 
 518 }
 519 
 520 //------------------------------builtin_throw----------------------------------
 521 void GraphKit::builtin_throw(Deoptimization::DeoptReason reason, Node* arg) {
 522   bool must_throw = true;
 523 
 524   if (env()->jvmti_can_post_on_exceptions()) {
 525     // check if we must post exception events, take uncommon trap if so
 526     uncommon_trap_if_should_post_on_exceptions(reason, must_throw);
 527     // here if should_post_on_exceptions is false
 528     // continue on with the normal codegen
 529   }
 530 
 531   // If this particular condition has not yet happened at this
 532   // bytecode, then use the uncommon trap mechanism, and allow for
 533   // a future recompilation if several traps occur here.
 534   // If the throw is hot, try to use a more complicated inline mechanism
 535   // which keeps execution inside the compiled code.
 536   bool treat_throw_as_hot = false;
 537   ciMethodData* md = method()->method_data();
 538 
 539   if (ProfileTraps) {
 540     if (too_many_traps(reason)) {
 541       treat_throw_as_hot = true;
 542     }
 543     // (If there is no MDO at all, assume it is early in
 544     // execution, and that any deopts are part of the
 545     // startup transient, and don't need to be remembered.)
 546 
 547     // Also, if there is a local exception handler, treat all throws
 548     // as hot if there has been at least one in this method.
 549     if (C->trap_count(reason) != 0
 550         && method()->method_data()->trap_count(reason) != 0
 551         && has_ex_handler()) {
 552         treat_throw_as_hot = true;
 553     }
 554   }
 555 
 556   // If this throw happens frequently, an uncommon trap might cause
 557   // a performance pothole.  If there is a local exception handler,
 558   // and if this particular bytecode appears to be deoptimizing often,
 559   // let us handle the throw inline, with a preconstructed instance.
 560   // Note:   If the deopt count has blown up, the uncommon trap
 561   // runtime is going to flush this nmethod, not matter what.
 562   if (treat_throw_as_hot
 563       && (!StackTraceInThrowable || OmitStackTraceInFastThrow)) {
 564     // If the throw is local, we use a pre-existing instance and
 565     // punt on the backtrace.  This would lead to a missing backtrace
 566     // (a repeat of 4292742) if the backtrace object is ever asked
 567     // for its backtrace.
 568     // Fixing this remaining case of 4292742 requires some flavor of
 569     // escape analysis.  Leave that for the future.
 570     ciInstance* ex_obj = NULL;
 571     switch (reason) {
 572     case Deoptimization::Reason_null_check:
 573       ex_obj = env()->NullPointerException_instance();
 574       break;
 575     case Deoptimization::Reason_div0_check:
 576       ex_obj = env()->ArithmeticException_instance();
 577       break;
 578     case Deoptimization::Reason_range_check:
 579       ex_obj = env()->ArrayIndexOutOfBoundsException_instance();
 580       break;
 581     case Deoptimization::Reason_class_check:
 582       if (java_bc() == Bytecodes::_aastore) {
 583         ex_obj = env()->ArrayStoreException_instance();
 584       } else {
 585         ex_obj = env()->ClassCastException_instance();
 586       }
 587       break;
 588     }
 589     if (failing()) { stop(); return; }  // exception allocation might fail
 590     if (ex_obj != NULL) {
 591       // Cheat with a preallocated exception object.
 592       if (C->log() != NULL)
 593         C->log()->elem("hot_throw preallocated='1' reason='%s'",
 594                        Deoptimization::trap_reason_name(reason));
 595       const TypeInstPtr* ex_con  = TypeInstPtr::make(ex_obj);
 596       Node*              ex_node = _gvn.transform(ConNode::make(ex_con));
 597 
 598       // Clear the detail message of the preallocated exception object.
 599       // Weblogic sometimes mutates the detail message of exceptions
 600       // using reflection.
 601       int offset = java_lang_Throwable::get_detailMessage_offset();
 602       const TypePtr* adr_typ = ex_con->add_offset(offset);
 603 
 604       Node *adr = basic_plus_adr(ex_node, ex_node, offset);
 605       const TypeOopPtr* val_type = TypeOopPtr::make_from_klass(env()->String_klass());
 606       // Conservatively release stores of object references.
 607       Node *store = store_oop_to_object(control(), ex_node, adr, adr_typ, null(), val_type, T_OBJECT, MemNode::release);
 608 
 609       add_exception_state(make_exception_state(ex_node));
 610       return;
 611     }
 612   }
 613 
 614   // %%% Maybe add entry to OptoRuntime which directly throws the exc.?
 615   // It won't be much cheaper than bailing to the interp., since we'll
 616   // have to pass up all the debug-info, and the runtime will have to
 617   // create the stack trace.
 618 
 619   // Usual case:  Bail to interpreter.
 620   // Reserve the right to recompile if we haven't seen anything yet.
 621 
 622   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? C->method() : NULL;
 623   Deoptimization::DeoptAction action = Deoptimization::Action_maybe_recompile;
 624   if (treat_throw_as_hot
 625       && (method()->method_data()->trap_recompiled_at(bci(), m)
 626           || C->too_many_traps(reason))) {
 627     // We cannot afford to take more traps here.  Suffer in the interpreter.
 628     if (C->log() != NULL)
 629       C->log()->elem("hot_throw preallocated='0' reason='%s' mcount='%d'",
 630                      Deoptimization::trap_reason_name(reason),
 631                      C->trap_count(reason));
 632     action = Deoptimization::Action_none;
 633   }
 634 
 635   // "must_throw" prunes the JVM state to include only the stack, if there
 636   // are no local exception handlers.  This should cut down on register
 637   // allocation time and code size, by drastically reducing the number
 638   // of in-edges on the call to the uncommon trap.
 639 
 640   uncommon_trap(reason, action, (ciKlass*)NULL, (char*)NULL, must_throw);
 641 }
 642 
 643 
 644 //----------------------------PreserveJVMState---------------------------------
 645 PreserveJVMState::PreserveJVMState(GraphKit* kit, bool clone_map) {
 646   debug_only(kit->verify_map());
 647   _kit    = kit;
 648   _map    = kit->map();   // preserve the map
 649   _sp     = kit->sp();
 650   kit->set_map(clone_map ? kit->clone_map() : NULL);
 651 #ifdef ASSERT
 652   _bci    = kit->bci();
 653   Parse* parser = kit->is_Parse();
 654   int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo();
 655   _block  = block;
 656 #endif
 657 }
 658 PreserveJVMState::~PreserveJVMState() {
 659   GraphKit* kit = _kit;
 660 #ifdef ASSERT
 661   assert(kit->bci() == _bci, "bci must not shift");
 662   Parse* parser = kit->is_Parse();
 663   int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo();
 664   assert(block == _block,    "block must not shift");
 665 #endif
 666   kit->set_map(_map);
 667   kit->set_sp(_sp);
 668 }
 669 
 670 
 671 //-----------------------------BuildCutout-------------------------------------
 672 BuildCutout::BuildCutout(GraphKit* kit, Node* p, float prob, float cnt)
 673   : PreserveJVMState(kit)
 674 {
 675   assert(p->is_Con() || p->is_Bool(), "test must be a bool");
 676   SafePointNode* outer_map = _map;   // preserved map is caller's
 677   SafePointNode* inner_map = kit->map();
 678   IfNode* iff = kit->create_and_map_if(outer_map->control(), p, prob, cnt);
 679   outer_map->set_control(kit->gvn().transform( new IfTrueNode(iff) ));
 680   inner_map->set_control(kit->gvn().transform( new IfFalseNode(iff) ));
 681 }
 682 BuildCutout::~BuildCutout() {
 683   GraphKit* kit = _kit;
 684   assert(kit->stopped(), "cutout code must stop, throw, return, etc.");
 685 }
 686 
 687 //---------------------------PreserveReexecuteState----------------------------
 688 PreserveReexecuteState::PreserveReexecuteState(GraphKit* kit) {
 689   assert(!kit->stopped(), "must call stopped() before");
 690   _kit    =    kit;
 691   _sp     =    kit->sp();
 692   _reexecute = kit->jvms()->_reexecute;
 693 }
 694 PreserveReexecuteState::~PreserveReexecuteState() {
 695   if (_kit->stopped()) return;
 696   _kit->jvms()->_reexecute = _reexecute;
 697   _kit->set_sp(_sp);
 698 }
 699 
 700 //------------------------------clone_map--------------------------------------
 701 // Implementation of PreserveJVMState
 702 //
 703 // Only clone_map(...) here. If this function is only used in the
 704 // PreserveJVMState class we may want to get rid of this extra
 705 // function eventually and do it all there.
 706 
 707 SafePointNode* GraphKit::clone_map() {
 708   if (map() == NULL)  return NULL;
 709 
 710   // Clone the memory edge first
 711   Node* mem = MergeMemNode::make(map()->memory());
 712   gvn().set_type_bottom(mem);
 713 
 714   SafePointNode *clonemap = (SafePointNode*)map()->clone();
 715   JVMState* jvms = this->jvms();
 716   JVMState* clonejvms = jvms->clone_shallow(C);
 717   clonemap->set_memory(mem);
 718   clonemap->set_jvms(clonejvms);
 719   clonejvms->set_map(clonemap);
 720   record_for_igvn(clonemap);
 721   gvn().set_type_bottom(clonemap);
 722   return clonemap;
 723 }
 724 
 725 
 726 //-----------------------------set_map_clone-----------------------------------
 727 void GraphKit::set_map_clone(SafePointNode* m) {
 728   _map = m;
 729   _map = clone_map();
 730   _map->set_next_exception(NULL);
 731   debug_only(verify_map());
 732 }
 733 
 734 
 735 //----------------------------kill_dead_locals---------------------------------
 736 // Detect any locals which are known to be dead, and force them to top.
 737 void GraphKit::kill_dead_locals() {
 738   // Consult the liveness information for the locals.  If any
 739   // of them are unused, then they can be replaced by top().  This
 740   // should help register allocation time and cut down on the size
 741   // of the deoptimization information.
 742 
 743   // This call is made from many of the bytecode handling
 744   // subroutines called from the Big Switch in do_one_bytecode.
 745   // Every bytecode which might include a slow path is responsible
 746   // for killing its dead locals.  The more consistent we
 747   // are about killing deads, the fewer useless phis will be
 748   // constructed for them at various merge points.
 749 
 750   // bci can be -1 (InvocationEntryBci).  We return the entry
 751   // liveness for the method.
 752 
 753   if (method() == NULL || method()->code_size() == 0) {
 754     // We are building a graph for a call to a native method.
 755     // All locals are live.
 756     return;
 757   }
 758 
 759   ResourceMark rm;
 760 
 761   // Consult the liveness information for the locals.  If any
 762   // of them are unused, then they can be replaced by top().  This
 763   // should help register allocation time and cut down on the size
 764   // of the deoptimization information.
 765   MethodLivenessResult live_locals = method()->liveness_at_bci(bci());
 766 
 767   int len = (int)live_locals.size();
 768   assert(len <= jvms()->loc_size(), "too many live locals");
 769   for (int local = 0; local < len; local++) {
 770     if (!live_locals.at(local)) {
 771       set_local(local, top());
 772     }
 773   }
 774 }
 775 
 776 #ifdef ASSERT
 777 //-------------------------dead_locals_are_killed------------------------------
 778 // Return true if all dead locals are set to top in the map.
 779 // Used to assert "clean" debug info at various points.
 780 bool GraphKit::dead_locals_are_killed() {
 781   if (method() == NULL || method()->code_size() == 0) {
 782     // No locals need to be dead, so all is as it should be.
 783     return true;
 784   }
 785 
 786   // Make sure somebody called kill_dead_locals upstream.
 787   ResourceMark rm;
 788   for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) {
 789     if (jvms->loc_size() == 0)  continue;  // no locals to consult
 790     SafePointNode* map = jvms->map();
 791     ciMethod* method = jvms->method();
 792     int       bci    = jvms->bci();
 793     if (jvms == this->jvms()) {
 794       bci = this->bci();  // it might not yet be synched
 795     }
 796     MethodLivenessResult live_locals = method->liveness_at_bci(bci);
 797     int len = (int)live_locals.size();
 798     if (!live_locals.is_valid() || len == 0)
 799       // This method is trivial, or is poisoned by a breakpoint.
 800       return true;
 801     assert(len == jvms->loc_size(), "live map consistent with locals map");
 802     for (int local = 0; local < len; local++) {
 803       if (!live_locals.at(local) && map->local(jvms, local) != top()) {
 804         if (PrintMiscellaneous && (Verbose || WizardMode)) {
 805           tty->print_cr("Zombie local %d: ", local);
 806           jvms->dump();
 807         }
 808         return false;
 809       }
 810     }
 811   }
 812   return true;
 813 }
 814 
 815 #endif //ASSERT
 816 
 817 // Helper function for enforcing certain bytecodes to reexecute if
 818 // deoptimization happens
 819 static bool should_reexecute_implied_by_bytecode(JVMState *jvms, bool is_anewarray) {
 820   ciMethod* cur_method = jvms->method();
 821   int       cur_bci   = jvms->bci();
 822   if (cur_method != NULL && cur_bci != InvocationEntryBci) {
 823     Bytecodes::Code code = cur_method->java_code_at_bci(cur_bci);
 824     return Interpreter::bytecode_should_reexecute(code) ||
 825            is_anewarray && code == Bytecodes::_multianewarray;
 826     // Reexecute _multianewarray bytecode which was replaced with
 827     // sequence of [a]newarray. See Parse::do_multianewarray().
 828     //
 829     // Note: interpreter should not have it set since this optimization
 830     // is limited by dimensions and guarded by flag so in some cases
 831     // multianewarray() runtime calls will be generated and
 832     // the bytecode should not be reexecutes (stack will not be reset).
 833   } else
 834     return false;
 835 }
 836 
 837 // Helper function for adding JVMState and debug information to node
 838 void GraphKit::add_safepoint_edges(SafePointNode* call, bool must_throw) {
 839   // Add the safepoint edges to the call (or other safepoint).
 840 
 841   // Make sure dead locals are set to top.  This
 842   // should help register allocation time and cut down on the size
 843   // of the deoptimization information.
 844   assert(dead_locals_are_killed(), "garbage in debug info before safepoint");
 845 
 846   // Walk the inline list to fill in the correct set of JVMState's
 847   // Also fill in the associated edges for each JVMState.
 848 
 849   // If the bytecode needs to be reexecuted we need to put
 850   // the arguments back on the stack.
 851   const bool should_reexecute = jvms()->should_reexecute();
 852   JVMState* youngest_jvms = should_reexecute ? sync_jvms_for_reexecute() : sync_jvms();
 853 
 854   // NOTE: set_bci (called from sync_jvms) might reset the reexecute bit to
 855   // undefined if the bci is different.  This is normal for Parse but it
 856   // should not happen for LibraryCallKit because only one bci is processed.
 857   assert(!is_LibraryCallKit() || (jvms()->should_reexecute() == should_reexecute),
 858          "in LibraryCallKit the reexecute bit should not change");
 859 
 860   // If we are guaranteed to throw, we can prune everything but the
 861   // input to the current bytecode.
 862   bool can_prune_locals = false;
 863   uint stack_slots_not_pruned = 0;
 864   int inputs = 0, depth = 0;
 865   if (must_throw) {
 866     assert(method() == youngest_jvms->method(), "sanity");
 867     if (compute_stack_effects(inputs, depth)) {
 868       can_prune_locals = true;
 869       stack_slots_not_pruned = inputs;
 870     }
 871   }
 872 
 873   if (env()->should_retain_local_variables()) {
 874     // At any safepoint, this method can get breakpointed, which would
 875     // then require an immediate deoptimization.
 876     can_prune_locals = false;  // do not prune locals
 877     stack_slots_not_pruned = 0;
 878   }
 879 
 880   // do not scribble on the input jvms
 881   JVMState* out_jvms = youngest_jvms->clone_deep(C);
 882   call->set_jvms(out_jvms); // Start jvms list for call node
 883 
 884   // For a known set of bytecodes, the interpreter should reexecute them if
 885   // deoptimization happens. We set the reexecute state for them here
 886   if (out_jvms->is_reexecute_undefined() && //don't change if already specified
 887       should_reexecute_implied_by_bytecode(out_jvms, call->is_AllocateArray())) {
 888     out_jvms->set_should_reexecute(true); //NOTE: youngest_jvms not changed
 889   }
 890 
 891   // Presize the call:
 892   DEBUG_ONLY(uint non_debug_edges = call->req());
 893   call->add_req_batch(top(), youngest_jvms->debug_depth());
 894   assert(call->req() == non_debug_edges + youngest_jvms->debug_depth(), "");
 895 
 896   // Set up edges so that the call looks like this:
 897   //  Call [state:] ctl io mem fptr retadr
 898   //       [parms:] parm0 ... parmN
 899   //       [root:]  loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN
 900   //    [...mid:]   loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN [...]
 901   //       [young:] loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN
 902   // Note that caller debug info precedes callee debug info.
 903 
 904   // Fill pointer walks backwards from "young:" to "root:" in the diagram above:
 905   uint debug_ptr = call->req();
 906 
 907   // Loop over the map input edges associated with jvms, add them
 908   // to the call node, & reset all offsets to match call node array.
 909   for (JVMState* in_jvms = youngest_jvms; in_jvms != NULL; ) {
 910     uint debug_end   = debug_ptr;
 911     uint debug_start = debug_ptr - in_jvms->debug_size();
 912     debug_ptr = debug_start;  // back up the ptr
 913 
 914     uint p = debug_start;  // walks forward in [debug_start, debug_end)
 915     uint j, k, l;
 916     SafePointNode* in_map = in_jvms->map();
 917     out_jvms->set_map(call);
 918 
 919     if (can_prune_locals) {
 920       assert(in_jvms->method() == out_jvms->method(), "sanity");
 921       // If the current throw can reach an exception handler in this JVMS,
 922       // then we must keep everything live that can reach that handler.
 923       // As a quick and dirty approximation, we look for any handlers at all.
 924       if (in_jvms->method()->has_exception_handlers()) {
 925         can_prune_locals = false;
 926       }
 927     }
 928 
 929     // Add the Locals
 930     k = in_jvms->locoff();
 931     l = in_jvms->loc_size();
 932     out_jvms->set_locoff(p);
 933     if (!can_prune_locals) {
 934       for (j = 0; j < l; j++)
 935         call->set_req(p++, in_map->in(k+j));
 936     } else {
 937       p += l;  // already set to top above by add_req_batch
 938     }
 939 
 940     // Add the Expression Stack
 941     k = in_jvms->stkoff();
 942     l = in_jvms->sp();
 943     out_jvms->set_stkoff(p);
 944     if (!can_prune_locals) {
 945       for (j = 0; j < l; j++)
 946         call->set_req(p++, in_map->in(k+j));
 947     } else if (can_prune_locals && stack_slots_not_pruned != 0) {
 948       // Divide stack into {S0,...,S1}, where S0 is set to top.
 949       uint s1 = stack_slots_not_pruned;
 950       stack_slots_not_pruned = 0;  // for next iteration
 951       if (s1 > l)  s1 = l;
 952       uint s0 = l - s1;
 953       p += s0;  // skip the tops preinstalled by add_req_batch
 954       for (j = s0; j < l; j++)
 955         call->set_req(p++, in_map->in(k+j));
 956     } else {
 957       p += l;  // already set to top above by add_req_batch
 958     }
 959 
 960     // Add the Monitors
 961     k = in_jvms->monoff();
 962     l = in_jvms->mon_size();
 963     out_jvms->set_monoff(p);
 964     for (j = 0; j < l; j++)
 965       call->set_req(p++, in_map->in(k+j));
 966 
 967     // Copy any scalar object fields.
 968     k = in_jvms->scloff();
 969     l = in_jvms->scl_size();
 970     out_jvms->set_scloff(p);
 971     for (j = 0; j < l; j++)
 972       call->set_req(p++, in_map->in(k+j));
 973 
 974     // Finish the new jvms.
 975     out_jvms->set_endoff(p);
 976 
 977     assert(out_jvms->endoff()     == debug_end,             "fill ptr must match");
 978     assert(out_jvms->depth()      == in_jvms->depth(),      "depth must match");
 979     assert(out_jvms->loc_size()   == in_jvms->loc_size(),   "size must match");
 980     assert(out_jvms->mon_size()   == in_jvms->mon_size(),   "size must match");
 981     assert(out_jvms->scl_size()   == in_jvms->scl_size(),   "size must match");
 982     assert(out_jvms->debug_size() == in_jvms->debug_size(), "size must match");
 983 
 984     // Update the two tail pointers in parallel.
 985     out_jvms = out_jvms->caller();
 986     in_jvms  = in_jvms->caller();
 987   }
 988 
 989   assert(debug_ptr == non_debug_edges, "debug info must fit exactly");
 990 
 991   // Test the correctness of JVMState::debug_xxx accessors:
 992   assert(call->jvms()->debug_start() == non_debug_edges, "");
 993   assert(call->jvms()->debug_end()   == call->req(), "");
 994   assert(call->jvms()->debug_depth() == call->req() - non_debug_edges, "");
 995 }
 996 
 997 bool GraphKit::compute_stack_effects(int& inputs, int& depth) {
 998   Bytecodes::Code code = java_bc();
 999   if (code == Bytecodes::_wide) {
1000     code = method()->java_code_at_bci(bci() + 1);
1001   }
1002 
1003   BasicType rtype = T_ILLEGAL;
1004   int       rsize = 0;
1005 
1006   if (code != Bytecodes::_illegal) {
1007     depth = Bytecodes::depth(code); // checkcast=0, athrow=-1
1008     rtype = Bytecodes::result_type(code); // checkcast=P, athrow=V
1009     if (rtype < T_CONFLICT)
1010       rsize = type2size[rtype];
1011   }
1012 
1013   switch (code) {
1014   case Bytecodes::_illegal:
1015     return false;
1016 
1017   case Bytecodes::_ldc:
1018   case Bytecodes::_ldc_w:
1019   case Bytecodes::_ldc2_w:
1020     inputs = 0;
1021     break;
1022 
1023   case Bytecodes::_dup:         inputs = 1;  break;
1024   case Bytecodes::_dup_x1:      inputs = 2;  break;
1025   case Bytecodes::_dup_x2:      inputs = 3;  break;
1026   case Bytecodes::_dup2:        inputs = 2;  break;
1027   case Bytecodes::_dup2_x1:     inputs = 3;  break;
1028   case Bytecodes::_dup2_x2:     inputs = 4;  break;
1029   case Bytecodes::_swap:        inputs = 2;  break;
1030   case Bytecodes::_arraylength: inputs = 1;  break;
1031 
1032   case Bytecodes::_getstatic:
1033   case Bytecodes::_putstatic:
1034   case Bytecodes::_getfield:
1035   case Bytecodes::_vgetfield:
1036   case Bytecodes::_putfield:
1037     {
1038       bool ignored_will_link;
1039       ciField* field = method()->get_field_at_bci(bci(), ignored_will_link);
1040       int      size  = field->type()->size();
1041       bool is_get = (depth >= 0), is_static = (depth & 1);
1042       inputs = (is_static ? 0 : 1);
1043       if (is_get) {
1044         depth = size - inputs;
1045       } else {
1046         inputs += size;        // putxxx pops the value from the stack
1047         depth = - inputs;
1048       }
1049     }
1050     break;
1051 
1052   case Bytecodes::_invokevirtual:
1053   case Bytecodes::_invokedirect:
1054   case Bytecodes::_invokespecial:
1055   case Bytecodes::_invokestatic:
1056   case Bytecodes::_invokedynamic:
1057   case Bytecodes::_invokeinterface:
1058     {
1059       bool ignored_will_link;
1060       ciSignature* declared_signature = NULL;
1061       ciMethod* ignored_callee = method()->get_method_at_bci(bci(), ignored_will_link, &declared_signature);
1062       assert(declared_signature != NULL, "cannot be null");
1063       inputs   = declared_signature->arg_size_for_bc(code);
1064       int size = declared_signature->return_type()->size();
1065       depth = size - inputs;
1066     }
1067     break;
1068 
1069   case Bytecodes::_multianewarray:
1070     {
1071       ciBytecodeStream iter(method());
1072       iter.reset_to_bci(bci());
1073       iter.next();
1074       inputs = iter.get_dimensions();
1075       assert(rsize == 1, "");
1076       depth = rsize - inputs;
1077     }
1078     break;
1079 
1080   case Bytecodes::_vnew: {
1081     // vnew pops the values from the stack
1082     ciValueKlass* vk = method()->holder()->as_value_klass();
1083     inputs = vk->field_size();
1084     depth = rsize - inputs;
1085     break;
1086   }
1087   case Bytecodes::_vwithfield: {
1088     bool ignored_will_link;
1089     ciField* field = method()->get_field_at_bci(bci(), ignored_will_link);
1090     int      size  = field->type()->size();
1091     inputs = size+1;
1092     depth = rsize - inputs;
1093     break;
1094   }
1095 
1096   case Bytecodes::_ireturn:
1097   case Bytecodes::_lreturn:
1098   case Bytecodes::_freturn:
1099   case Bytecodes::_dreturn:
1100   case Bytecodes::_areturn:
1101   case Bytecodes::_vreturn:
1102     assert(rsize = -depth, "");
1103     inputs = rsize;
1104     break;
1105 
1106   case Bytecodes::_jsr:
1107   case Bytecodes::_jsr_w:
1108     inputs = 0;
1109     depth  = 1;                  // S.B. depth=1, not zero
1110     break;
1111 
1112   default:
1113     // bytecode produces a typed result
1114     inputs = rsize - depth;
1115     assert(inputs >= 0, "");
1116     break;
1117   }
1118 
1119 #ifdef ASSERT
1120   // spot check
1121   int outputs = depth + inputs;
1122   assert(outputs >= 0, "sanity");
1123   switch (code) {
1124   case Bytecodes::_checkcast: assert(inputs == 1 && outputs == 1, ""); break;
1125   case Bytecodes::_athrow:    assert(inputs == 1 && outputs == 0, ""); break;
1126   case Bytecodes::_aload_0:   assert(inputs == 0 && outputs == 1, ""); break;
1127   case Bytecodes::_return:    assert(inputs == 0 && outputs == 0, ""); break;
1128   case Bytecodes::_drem:      assert(inputs == 4 && outputs == 2, ""); break;
1129   }
1130 #endif //ASSERT
1131 
1132   return true;
1133 }
1134 
1135 
1136 
1137 //------------------------------basic_plus_adr---------------------------------
1138 Node* GraphKit::basic_plus_adr(Node* base, Node* ptr, Node* offset) {
1139   // short-circuit a common case
1140   if (offset == intcon(0))  return ptr;
1141   return _gvn.transform( new AddPNode(base, ptr, offset) );
1142 }
1143 
1144 Node* GraphKit::ConvI2L(Node* offset) {
1145   // short-circuit a common case
1146   jint offset_con = find_int_con(offset, Type::OffsetBot);
1147   if (offset_con != Type::OffsetBot) {
1148     return longcon((jlong) offset_con);
1149   }
1150   return _gvn.transform( new ConvI2LNode(offset));
1151 }
1152 
1153 Node* GraphKit::ConvI2UL(Node* offset) {
1154   juint offset_con = (juint) find_int_con(offset, Type::OffsetBot);
1155   if (offset_con != (juint) Type::OffsetBot) {
1156     return longcon((julong) offset_con);
1157   }
1158   Node* conv = _gvn.transform( new ConvI2LNode(offset));
1159   Node* mask = _gvn.transform(ConLNode::make((julong) max_juint));
1160   return _gvn.transform( new AndLNode(conv, mask) );
1161 }
1162 
1163 Node* GraphKit::ConvL2I(Node* offset) {
1164   // short-circuit a common case
1165   jlong offset_con = find_long_con(offset, (jlong)Type::OffsetBot);
1166   if (offset_con != (jlong)Type::OffsetBot) {
1167     return intcon((int) offset_con);
1168   }
1169   return _gvn.transform( new ConvL2INode(offset));
1170 }
1171 
1172 //-------------------------load_object_klass-----------------------------------
1173 Node* GraphKit::load_object_klass(Node* obj) {
1174   // Special-case a fresh allocation to avoid building nodes:
1175   Node* akls = AllocateNode::Ideal_klass(obj, &_gvn);
1176   if (akls != NULL)  return akls;
1177   Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes());
1178   return _gvn.transform(LoadKlassNode::make(_gvn, NULL, immutable_memory(), k_adr, TypeInstPtr::KLASS));
1179 }
1180 
1181 //-------------------------load_array_length-----------------------------------
1182 Node* GraphKit::load_array_length(Node* array) {
1183   // Special-case a fresh allocation to avoid building nodes:
1184   AllocateArrayNode* alloc = AllocateArrayNode::Ideal_array_allocation(array, &_gvn);
1185   Node *alen;
1186   if (alloc == NULL) {
1187     Node *r_adr = basic_plus_adr(array, arrayOopDesc::length_offset_in_bytes());
1188     alen = _gvn.transform( new LoadRangeNode(0, immutable_memory(), r_adr, TypeInt::POS));
1189   } else {
1190     alen = alloc->Ideal_length();
1191     Node* ccast = alloc->make_ideal_length(_gvn.type(array)->is_oopptr(), &_gvn);
1192     if (ccast != alen) {
1193       alen = _gvn.transform(ccast);
1194     }
1195   }
1196   return alen;
1197 }
1198 
1199 //------------------------------do_null_check----------------------------------
1200 // Helper function to do a NULL pointer check.  Returned value is
1201 // the incoming address with NULL casted away.  You are allowed to use the
1202 // not-null value only if you are control dependent on the test.
1203 #ifndef PRODUCT
1204 extern int explicit_null_checks_inserted,
1205            explicit_null_checks_elided;
1206 #endif
1207 Node* GraphKit::null_check_common(Node* value, BasicType type,
1208                                   // optional arguments for variations:
1209                                   bool assert_null,
1210                                   Node* *null_control,
1211                                   bool speculative) {
1212   assert(!assert_null || null_control == NULL, "not both at once");
1213   if (stopped())  return top();
1214   if (!GenerateCompilerNullChecks && !assert_null && null_control == NULL) {
1215     // For some performance testing, we may wish to suppress null checking.
1216     value = cast_not_null(value);   // Make it appear to be non-null (4962416).
1217     return value;
1218   }
1219   NOT_PRODUCT(explicit_null_checks_inserted++);
1220 
1221   // Construct NULL check
1222   Node *chk = NULL;
1223   switch(type) {
1224     case T_LONG   : chk = new CmpLNode(value, _gvn.zerocon(T_LONG)); break;
1225     case T_INT    : chk = new CmpINode(value, _gvn.intcon(0)); break;
1226     case T_ARRAY  : // fall through
1227       type = T_OBJECT;  // simplify further tests
1228     case T_OBJECT : {
1229       const Type *t = _gvn.type( value );
1230 
1231       const TypeOopPtr* tp = t->isa_oopptr();
1232       if (tp != NULL && tp->klass() != NULL && !tp->klass()->is_loaded()
1233           // Only for do_null_check, not any of its siblings:
1234           && !assert_null && null_control == NULL) {
1235         // Usually, any field access or invocation on an unloaded oop type
1236         // will simply fail to link, since the statically linked class is
1237         // likely also to be unloaded.  However, in -Xcomp mode, sometimes
1238         // the static class is loaded but the sharper oop type is not.
1239         // Rather than checking for this obscure case in lots of places,
1240         // we simply observe that a null check on an unloaded class
1241         // will always be followed by a nonsense operation, so we
1242         // can just issue the uncommon trap here.
1243         // Our access to the unloaded class will only be correct
1244         // after it has been loaded and initialized, which requires
1245         // a trip through the interpreter.
1246 #ifndef PRODUCT
1247         if (WizardMode) { tty->print("Null check of unloaded "); tp->klass()->print(); tty->cr(); }
1248 #endif
1249         uncommon_trap(Deoptimization::Reason_unloaded,
1250                       Deoptimization::Action_reinterpret,
1251                       tp->klass(), "!loaded");
1252         return top();
1253       }
1254 
1255       if (assert_null) {
1256         // See if the type is contained in NULL_PTR.
1257         // If so, then the value is already null.
1258         if (t->higher_equal(TypePtr::NULL_PTR)) {
1259           NOT_PRODUCT(explicit_null_checks_elided++);
1260           return value;           // Elided null assert quickly!
1261         }
1262       } else {
1263         // See if mixing in the NULL pointer changes type.
1264         // If so, then the NULL pointer was not allowed in the original
1265         // type.  In other words, "value" was not-null.
1266         if (t->meet(TypePtr::NULL_PTR) != t->remove_speculative()) {
1267           // same as: if (!TypePtr::NULL_PTR->higher_equal(t)) ...
1268           NOT_PRODUCT(explicit_null_checks_elided++);
1269           return value;           // Elided null check quickly!
1270         }
1271       }
1272       chk = new CmpPNode( value, null() );
1273       break;
1274     }
1275 
1276     default:
1277       fatal("unexpected type: %s", type2name(type));
1278   }
1279   assert(chk != NULL, "sanity check");
1280   chk = _gvn.transform(chk);
1281 
1282   BoolTest::mask btest = assert_null ? BoolTest::eq : BoolTest::ne;
1283   BoolNode *btst = new BoolNode( chk, btest);
1284   Node   *tst = _gvn.transform( btst );
1285 
1286   //-----------
1287   // if peephole optimizations occurred, a prior test existed.
1288   // If a prior test existed, maybe it dominates as we can avoid this test.
1289   if (tst != btst && type == T_OBJECT) {
1290     // At this point we want to scan up the CFG to see if we can
1291     // find an identical test (and so avoid this test altogether).
1292     Node *cfg = control();
1293     int depth = 0;
1294     while( depth < 16 ) {       // Limit search depth for speed
1295       if( cfg->Opcode() == Op_IfTrue &&
1296           cfg->in(0)->in(1) == tst ) {
1297         // Found prior test.  Use "cast_not_null" to construct an identical
1298         // CastPP (and hence hash to) as already exists for the prior test.
1299         // Return that casted value.
1300         if (assert_null) {
1301           replace_in_map(value, null());
1302           return null();  // do not issue the redundant test
1303         }
1304         Node *oldcontrol = control();
1305         set_control(cfg);
1306         Node *res = cast_not_null(value);
1307         set_control(oldcontrol);
1308         NOT_PRODUCT(explicit_null_checks_elided++);
1309         return res;
1310       }
1311       cfg = IfNode::up_one_dom(cfg, /*linear_only=*/ true);
1312       if (cfg == NULL)  break;  // Quit at region nodes
1313       depth++;
1314     }
1315   }
1316 
1317   //-----------
1318   // Branch to failure if null
1319   float ok_prob = PROB_MAX;  // a priori estimate:  nulls never happen
1320   Deoptimization::DeoptReason reason;
1321   if (assert_null) {
1322     reason = Deoptimization::Reason_null_assert;
1323   } else if (type == T_OBJECT) {
1324     reason = Deoptimization::reason_null_check(speculative);
1325   } else {
1326     reason = Deoptimization::Reason_div0_check;
1327   }
1328   // %%% Since Reason_unhandled is not recorded on a per-bytecode basis,
1329   // ciMethodData::has_trap_at will return a conservative -1 if any
1330   // must-be-null assertion has failed.  This could cause performance
1331   // problems for a method after its first do_null_assert failure.
1332   // Consider using 'Reason_class_check' instead?
1333 
1334   // To cause an implicit null check, we set the not-null probability
1335   // to the maximum (PROB_MAX).  For an explicit check the probability
1336   // is set to a smaller value.
1337   if (null_control != NULL || too_many_traps(reason)) {
1338     // probability is less likely
1339     ok_prob =  PROB_LIKELY_MAG(3);
1340   } else if (!assert_null &&
1341              (ImplicitNullCheckThreshold > 0) &&
1342              method() != NULL &&
1343              (method()->method_data()->trap_count(reason)
1344               >= (uint)ImplicitNullCheckThreshold)) {
1345     ok_prob =  PROB_LIKELY_MAG(3);
1346   }
1347 
1348   if (null_control != NULL) {
1349     IfNode* iff = create_and_map_if(control(), tst, ok_prob, COUNT_UNKNOWN);
1350     Node* null_true = _gvn.transform( new IfFalseNode(iff));
1351     set_control(      _gvn.transform( new IfTrueNode(iff)));
1352 #ifndef PRODUCT
1353     if (null_true == top()) {
1354       explicit_null_checks_elided++;
1355     }
1356 #endif
1357     (*null_control) = null_true;
1358   } else {
1359     BuildCutout unless(this, tst, ok_prob);
1360     // Check for optimizer eliding test at parse time
1361     if (stopped()) {
1362       // Failure not possible; do not bother making uncommon trap.
1363       NOT_PRODUCT(explicit_null_checks_elided++);
1364     } else if (assert_null) {
1365       uncommon_trap(reason,
1366                     Deoptimization::Action_make_not_entrant,
1367                     NULL, "assert_null");
1368     } else {
1369       replace_in_map(value, zerocon(type));
1370       builtin_throw(reason);
1371     }
1372   }
1373 
1374   // Must throw exception, fall-thru not possible?
1375   if (stopped()) {
1376     return top();               // No result
1377   }
1378 
1379   if (assert_null) {
1380     // Cast obj to null on this path.
1381     replace_in_map(value, zerocon(type));
1382     return zerocon(type);
1383   }
1384 
1385   // Cast obj to not-null on this path, if there is no null_control.
1386   // (If there is a null_control, a non-null value may come back to haunt us.)
1387   if (type == T_OBJECT) {
1388     Node* cast = cast_not_null(value, false);
1389     if (null_control == NULL || (*null_control) == top())
1390       replace_in_map(value, cast);
1391     value = cast;
1392   }
1393 
1394   return value;
1395 }
1396 
1397 
1398 //------------------------------cast_not_null----------------------------------
1399 // Cast obj to not-null on this path
1400 Node* GraphKit::cast_not_null(Node* obj, bool do_replace_in_map) {
1401   const Type *t = _gvn.type(obj);
1402   const Type *t_not_null = t->join_speculative(TypePtr::NOTNULL);
1403   // Object is already not-null?
1404   if( t == t_not_null ) return obj;
1405 
1406   Node *cast = new CastPPNode(obj,t_not_null);
1407   cast->init_req(0, control());
1408   cast = _gvn.transform( cast );
1409 
1410   // Scan for instances of 'obj' in the current JVM mapping.
1411   // These instances are known to be not-null after the test.
1412   if (do_replace_in_map)
1413     replace_in_map(obj, cast);
1414 
1415   return cast;                  // Return casted value
1416 }
1417 
1418 
1419 //--------------------------replace_in_map-------------------------------------
1420 void GraphKit::replace_in_map(Node* old, Node* neww) {
1421   if (old == neww) {
1422     return;
1423   }
1424 
1425   map()->replace_edge(old, neww);
1426 
1427   // Note: This operation potentially replaces any edge
1428   // on the map.  This includes locals, stack, and monitors
1429   // of the current (innermost) JVM state.
1430 
1431   // don't let inconsistent types from profiling escape this
1432   // method
1433 
1434   const Type* told = _gvn.type(old);
1435   const Type* tnew = _gvn.type(neww);
1436 
1437   if (!tnew->higher_equal(told)) {
1438     return;
1439   }
1440 
1441   map()->record_replaced_node(old, neww);
1442 }
1443 
1444 
1445 //=============================================================================
1446 //--------------------------------memory---------------------------------------
1447 Node* GraphKit::memory(uint alias_idx) {
1448   MergeMemNode* mem = merged_memory();
1449   Node* p = mem->memory_at(alias_idx);
1450   _gvn.set_type(p, Type::MEMORY);  // must be mapped
1451   return p;
1452 }
1453 
1454 //-----------------------------reset_memory------------------------------------
1455 Node* GraphKit::reset_memory() {
1456   Node* mem = map()->memory();
1457   // do not use this node for any more parsing!
1458   debug_only( map()->set_memory((Node*)NULL) );
1459   return _gvn.transform( mem );
1460 }
1461 
1462 //------------------------------set_all_memory---------------------------------
1463 void GraphKit::set_all_memory(Node* newmem) {
1464   Node* mergemem = MergeMemNode::make(newmem);
1465   gvn().set_type_bottom(mergemem);
1466   map()->set_memory(mergemem);
1467 }
1468 
1469 //------------------------------set_all_memory_call----------------------------
1470 void GraphKit::set_all_memory_call(Node* call, bool separate_io_proj) {
1471   Node* newmem = _gvn.transform( new ProjNode(call, TypeFunc::Memory, separate_io_proj) );
1472   set_all_memory(newmem);
1473 }
1474 
1475 //=============================================================================
1476 //
1477 // parser factory methods for MemNodes
1478 //
1479 // These are layered on top of the factory methods in LoadNode and StoreNode,
1480 // and integrate with the parser's memory state and _gvn engine.
1481 //
1482 
1483 // factory methods in "int adr_idx"
1484 Node* GraphKit::make_load(Node* ctl, Node* adr, const Type* t, BasicType bt,
1485                           int adr_idx,
1486                           MemNode::MemOrd mo,
1487                           LoadNode::ControlDependency control_dependency,
1488                           bool require_atomic_access,
1489                           bool unaligned,
1490                           bool mismatched) {
1491   assert(adr_idx != Compile::AliasIdxTop, "use other make_load factory" );
1492   const TypePtr* adr_type = NULL; // debug-mode-only argument
1493   debug_only(adr_type = C->get_adr_type(adr_idx));
1494   Node* mem = memory(adr_idx);
1495   Node* ld;
1496   if (require_atomic_access && bt == T_LONG) {
1497     ld = LoadLNode::make_atomic(ctl, mem, adr, adr_type, t, mo, control_dependency, unaligned, mismatched);
1498   } else if (require_atomic_access && bt == T_DOUBLE) {
1499     ld = LoadDNode::make_atomic(ctl, mem, adr, adr_type, t, mo, control_dependency, unaligned, mismatched);
1500   } else {
1501     ld = LoadNode::make(_gvn, ctl, mem, adr, adr_type, t, bt, mo, control_dependency, unaligned, mismatched);
1502   }
1503   ld = _gvn.transform(ld);
1504 
1505   if (bt == T_VALUETYPE) {
1506     // Load value type from oop
1507     ld = ValueTypeNode::make(gvn(), map()->memory(), ld);
1508   } else if ((bt == T_OBJECT) && C->do_escape_analysis() || C->eliminate_boxing()) {
1509     // Improve graph before escape analysis and boxing elimination.
1510     record_for_igvn(ld);
1511   }
1512   return ld;
1513 }
1514 
1515 Node* GraphKit::store_to_memory(Node* ctl, Node* adr, Node *val, BasicType bt,
1516                                 int adr_idx,
1517                                 MemNode::MemOrd mo,
1518                                 bool require_atomic_access,
1519                                 bool unaligned,
1520                                 bool mismatched) {
1521   assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
1522   const TypePtr* adr_type = NULL;
1523   debug_only(adr_type = C->get_adr_type(adr_idx));
1524   Node *mem = memory(adr_idx);
1525   Node* st;
1526   if (require_atomic_access && bt == T_LONG) {
1527     st = StoreLNode::make_atomic(ctl, mem, adr, adr_type, val, mo);
1528   } else if (require_atomic_access && bt == T_DOUBLE) {
1529     st = StoreDNode::make_atomic(ctl, mem, adr, adr_type, val, mo);
1530   } else {
1531     st = StoreNode::make(_gvn, ctl, mem, adr, adr_type, val, bt, mo);
1532   }
1533   if (unaligned) {
1534     st->as_Store()->set_unaligned_access();
1535   }
1536   if (mismatched) {
1537     st->as_Store()->set_mismatched_access();
1538   }
1539   st = _gvn.transform(st);
1540   set_memory(st, adr_idx);
1541   // Back-to-back stores can only remove intermediate store with DU info
1542   // so push on worklist for optimizer.
1543   if (mem->req() > MemNode::Address && adr == mem->in(MemNode::Address))
1544     record_for_igvn(st);
1545 
1546   return st;
1547 }
1548 
1549 
1550 void GraphKit::pre_barrier(bool do_load,
1551                            Node* ctl,
1552                            Node* obj,
1553                            Node* adr,
1554                            uint  adr_idx,
1555                            Node* val,
1556                            const TypeOopPtr* val_type,
1557                            Node* pre_val,
1558                            BasicType bt) {
1559 
1560   BarrierSet* bs = Universe::heap()->barrier_set();
1561   set_control(ctl);
1562   switch (bs->kind()) {
1563     case BarrierSet::G1SATBCTLogging:
1564       g1_write_barrier_pre(do_load, obj, adr, adr_idx, val, val_type, pre_val, bt);
1565       break;
1566 
1567     case BarrierSet::CardTableForRS:
1568     case BarrierSet::CardTableExtension:
1569     case BarrierSet::ModRef:
1570       break;
1571 
1572     default      :
1573       ShouldNotReachHere();
1574 
1575   }
1576 }
1577 
1578 bool GraphKit::can_move_pre_barrier() const {
1579   BarrierSet* bs = Universe::heap()->barrier_set();
1580   switch (bs->kind()) {
1581     case BarrierSet::G1SATBCTLogging:
1582       return true; // Can move it if no safepoint
1583 
1584     case BarrierSet::CardTableForRS:
1585     case BarrierSet::CardTableExtension:
1586     case BarrierSet::ModRef:
1587       return true; // There is no pre-barrier
1588 
1589     default      :
1590       ShouldNotReachHere();
1591   }
1592   return false;
1593 }
1594 
1595 void GraphKit::post_barrier(Node* ctl,
1596                             Node* store,
1597                             Node* obj,
1598                             Node* adr,
1599                             uint  adr_idx,
1600                             Node* val,
1601                             BasicType bt,
1602                             bool use_precise) {
1603   BarrierSet* bs = Universe::heap()->barrier_set();
1604   set_control(ctl);
1605   switch (bs->kind()) {
1606     case BarrierSet::G1SATBCTLogging:
1607       g1_write_barrier_post(store, obj, adr, adr_idx, val, bt, use_precise);
1608       break;
1609 
1610     case BarrierSet::CardTableForRS:
1611     case BarrierSet::CardTableExtension:
1612       write_barrier_post(store, obj, adr, adr_idx, val, use_precise);
1613       break;
1614 
1615     case BarrierSet::ModRef:
1616       break;
1617 
1618     default      :
1619       ShouldNotReachHere();
1620 
1621   }
1622 }
1623 
1624 Node* GraphKit::store_oop(Node* ctl,
1625                           Node* obj,
1626                           Node* adr,
1627                           const TypePtr* adr_type,
1628                           Node* val,
1629                           const TypeOopPtr* val_type,
1630                           BasicType bt,
1631                           bool use_precise,
1632                           MemNode::MemOrd mo,
1633                           bool mismatched) {
1634   // Transformation of a value which could be NULL pointer (CastPP #NULL)
1635   // could be delayed during Parse (for example, in adjust_map_after_if()).
1636   // Execute transformation here to avoid barrier generation in such case.
1637   if (_gvn.type(val) == TypePtr::NULL_PTR)
1638     val = _gvn.makecon(TypePtr::NULL_PTR);
1639 
1640   set_control(ctl);
1641   if (stopped()) return top(); // Dead path ?
1642 
1643   assert(bt == T_OBJECT || bt == T_VALUETYPE, "sanity");
1644   assert(val != NULL, "not dead path");
1645   uint adr_idx = C->get_alias_index(adr_type);
1646   assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
1647 
1648   if (bt == T_VALUETYPE) {
1649     // Allocate value type and store oop
1650     val = val->as_ValueType()->store_to_memory(this);
1651   }
1652 
1653   pre_barrier(true /* do_load */,
1654               control(), obj, adr, adr_idx, val, val_type,
1655               NULL /* pre_val */,
1656               bt);
1657 
1658   Node* store = store_to_memory(control(), adr, val, bt, adr_idx, mo, mismatched);
1659   post_barrier(control(), store, obj, adr, adr_idx, val, bt, use_precise);
1660   return store;
1661 }
1662 
1663 // Could be an array or object we don't know at compile time (unsafe ref.)
1664 Node* GraphKit::store_oop_to_unknown(Node* ctl,
1665                              Node* obj,   // containing obj
1666                              Node* adr,  // actual adress to store val at
1667                              const TypePtr* adr_type,
1668                              Node* val,
1669                              BasicType bt,
1670                              MemNode::MemOrd mo,
1671                              bool mismatched) {
1672   Compile::AliasType* at = C->alias_type(adr_type);
1673   const TypeOopPtr* val_type = NULL;
1674   if (adr_type->isa_instptr()) {
1675     if (at->field() != NULL) {
1676       // known field.  This code is a copy of the do_put_xxx logic.
1677       ciField* field = at->field();
1678       if (!field->type()->is_loaded()) {
1679         val_type = TypeInstPtr::BOTTOM;
1680       } else {
1681         val_type = TypeOopPtr::make_from_klass(field->type()->as_klass());
1682       }
1683     }
1684   } else if (adr_type->isa_aryptr()) {
1685     val_type = adr_type->is_aryptr()->elem()->make_oopptr();
1686   }
1687   if (val_type == NULL) {
1688     val_type = TypeInstPtr::BOTTOM;
1689   }
1690   return store_oop(ctl, obj, adr, adr_type, val, val_type, bt, true, mo, mismatched);
1691 }
1692 
1693 
1694 //-------------------------array_element_address-------------------------
1695 Node* GraphKit::array_element_address(Node* ary, Node* idx, BasicType elembt,
1696                                       const TypeInt* sizetype, Node* ctrl) {
1697   uint shift  = exact_log2(type2aelembytes(elembt));
1698   ciKlass* arytype_klass = _gvn.type(ary)->is_aryptr()->klass();
1699   if (arytype_klass->is_value_array_klass()) {
1700     ciValueArrayKlass* vak = arytype_klass->as_value_array_klass();
1701     shift = vak->log2_element_size();
1702   }
1703   uint header = arrayOopDesc::base_offset_in_bytes(elembt);
1704 
1705   // short-circuit a common case (saves lots of confusing waste motion)
1706   jint idx_con = find_int_con(idx, -1);
1707   if (idx_con >= 0) {
1708     intptr_t offset = header + ((intptr_t)idx_con << shift);
1709     return basic_plus_adr(ary, offset);
1710   }
1711 
1712   // must be correct type for alignment purposes
1713   Node* base  = basic_plus_adr(ary, header);
1714   idx = Compile::conv_I2X_index(&_gvn, idx, sizetype, ctrl);
1715   Node* scale = _gvn.transform( new LShiftXNode(idx, intcon(shift)) );
1716   return basic_plus_adr(ary, base, scale);
1717 }
1718 
1719 //-------------------------load_array_element-------------------------
1720 Node* GraphKit::load_array_element(Node* ctl, Node* ary, Node* idx, const TypeAryPtr* arytype) {
1721   const Type* elemtype = arytype->elem();
1722   BasicType elembt = elemtype->array_element_basic_type();
1723   assert(elembt != T_VALUETYPE, "value types are not supported by this method");
1724   Node* adr = array_element_address(ary, idx, elembt, arytype->size());
1725   Node* ld = make_load(ctl, adr, elemtype, elembt, arytype, MemNode::unordered);
1726   return ld;
1727 }
1728 
1729 //-------------------------set_arguments_for_java_call-------------------------
1730 // Arguments (pre-popped from the stack) are taken from the JVMS.
1731 void GraphKit::set_arguments_for_java_call(CallJavaNode* call) {
1732   // Add the call arguments:
1733   const TypeTuple* domain = call->tf()->domain_sig();
1734   uint nargs = domain->cnt();
1735   for (uint i = TypeFunc::Parms, idx = TypeFunc::Parms; i < nargs; i++) {
1736     Node* arg = argument(i-TypeFunc::Parms);
1737     if (ValueTypePassFieldsAsArgs) {
1738       if (arg->is_ValueType()) {
1739         ValueTypeNode* vt = arg->as_ValueType();
1740         if (domain->field_at(i)->is_valuetypeptr()->klass() != C->env()->___Value_klass()) {
1741           // We don't pass value type arguments by reference but instead
1742           // pass each field of the value type
1743           idx += vt->set_arguments_for_java_call(call, idx, *this);
1744         } else {
1745           arg = arg->as_ValueType()->store_to_memory(this);
1746           call->init_req(idx, arg);
1747           idx++;
1748         }
1749       } else {
1750         call->init_req(idx, arg);
1751         idx++;
1752       }
1753     } else {
1754       if (arg->is_ValueType()) {
1755         // Pass value type argument via oop to callee
1756         arg = arg->as_ValueType()->store_to_memory(this);
1757       }
1758       call->init_req(i, arg);
1759     }
1760   }
1761 }
1762 
1763 //---------------------------set_edges_for_java_call---------------------------
1764 // Connect a newly created call into the current JVMS.
1765 // A return value node (if any) is returned from set_edges_for_java_call.
1766 void GraphKit::set_edges_for_java_call(CallJavaNode* call, bool must_throw, bool separate_io_proj) {
1767 
1768   // Add the predefined inputs:
1769   call->init_req( TypeFunc::Control, control() );
1770   call->init_req( TypeFunc::I_O    , i_o() );
1771   call->init_req( TypeFunc::Memory , reset_memory() );
1772   call->init_req( TypeFunc::FramePtr, frameptr() );
1773   call->init_req( TypeFunc::ReturnAdr, top() );
1774 
1775   add_safepoint_edges(call, must_throw);
1776 
1777   Node* xcall = _gvn.transform(call);
1778 
1779   if (xcall == top()) {
1780     set_control(top());
1781     return;
1782   }
1783   assert(xcall == call, "call identity is stable");
1784 
1785   // Re-use the current map to produce the result.
1786 
1787   set_control(_gvn.transform(new ProjNode(call, TypeFunc::Control)));
1788   set_i_o(    _gvn.transform(new ProjNode(call, TypeFunc::I_O    , separate_io_proj)));
1789   set_all_memory_call(xcall, separate_io_proj);
1790 
1791   //return xcall;   // no need, caller already has it
1792 }
1793 
1794 Node* GraphKit::set_results_for_java_call(CallJavaNode* call, bool separate_io_proj) {
1795   if (stopped())  return top();  // maybe the call folded up?
1796 
1797   // Capture the return value, if any.
1798   Node* ret;
1799   if (call->method() == NULL ||
1800       call->method()->return_type()->basic_type() == T_VOID)
1801         ret = top();
1802   else  ret = _gvn.transform(new ProjNode(call, TypeFunc::Parms));
1803 
1804   // Note:  Since any out-of-line call can produce an exception,
1805   // we always insert an I_O projection from the call into the result.
1806 
1807   make_slow_call_ex(call, env()->Throwable_klass(), separate_io_proj);
1808 
1809   if (separate_io_proj) {
1810     // The caller requested separate projections be used by the fall
1811     // through and exceptional paths, so replace the projections for
1812     // the fall through path.
1813     set_i_o(_gvn.transform( new ProjNode(call, TypeFunc::I_O) ));
1814     set_all_memory(_gvn.transform( new ProjNode(call, TypeFunc::Memory) ));
1815   }
1816   return ret;
1817 }
1818 
1819 //--------------------set_predefined_input_for_runtime_call--------------------
1820 // Reading and setting the memory state is way conservative here.
1821 // The real problem is that I am not doing real Type analysis on memory,
1822 // so I cannot distinguish card mark stores from other stores.  Across a GC
1823 // point the Store Barrier and the card mark memory has to agree.  I cannot
1824 // have a card mark store and its barrier split across the GC point from
1825 // either above or below.  Here I get that to happen by reading ALL of memory.
1826 // A better answer would be to separate out card marks from other memory.
1827 // For now, return the input memory state, so that it can be reused
1828 // after the call, if this call has restricted memory effects.
1829 Node* GraphKit::set_predefined_input_for_runtime_call(SafePointNode* call) {
1830   // Set fixed predefined input arguments
1831   Node* memory = reset_memory();
1832   call->init_req( TypeFunc::Control,   control()  );
1833   call->init_req( TypeFunc::I_O,       top()      ); // does no i/o
1834   call->init_req( TypeFunc::Memory,    memory     ); // may gc ptrs
1835   call->init_req( TypeFunc::FramePtr,  frameptr() );
1836   call->init_req( TypeFunc::ReturnAdr, top()      );
1837   return memory;
1838 }
1839 
1840 //-------------------set_predefined_output_for_runtime_call--------------------
1841 // Set control and memory (not i_o) from the call.
1842 // If keep_mem is not NULL, use it for the output state,
1843 // except for the RawPtr output of the call, if hook_mem is TypeRawPtr::BOTTOM.
1844 // If hook_mem is NULL, this call produces no memory effects at all.
1845 // If hook_mem is a Java-visible memory slice (such as arraycopy operands),
1846 // then only that memory slice is taken from the call.
1847 // In the last case, we must put an appropriate memory barrier before
1848 // the call, so as to create the correct anti-dependencies on loads
1849 // preceding the call.
1850 void GraphKit::set_predefined_output_for_runtime_call(Node* call,
1851                                                       Node* keep_mem,
1852                                                       const TypePtr* hook_mem) {
1853   // no i/o
1854   set_control(_gvn.transform( new ProjNode(call,TypeFunc::Control) ));
1855   if (keep_mem) {
1856     // First clone the existing memory state
1857     set_all_memory(keep_mem);
1858     if (hook_mem != NULL) {
1859       // Make memory for the call
1860       Node* mem = _gvn.transform( new ProjNode(call, TypeFunc::Memory) );
1861       // Set the RawPtr memory state only.  This covers all the heap top/GC stuff
1862       // We also use hook_mem to extract specific effects from arraycopy stubs.
1863       set_memory(mem, hook_mem);
1864     }
1865     // ...else the call has NO memory effects.
1866 
1867     // Make sure the call advertises its memory effects precisely.
1868     // This lets us build accurate anti-dependences in gcm.cpp.
1869     assert(C->alias_type(call->adr_type()) == C->alias_type(hook_mem),
1870            "call node must be constructed correctly");
1871   } else {
1872     assert(hook_mem == NULL, "");
1873     // This is not a "slow path" call; all memory comes from the call.
1874     set_all_memory_call(call);
1875   }
1876 }
1877 
1878 
1879 // Replace the call with the current state of the kit.
1880 void GraphKit::replace_call(CallNode* call, Node* result, bool do_replaced_nodes) {
1881   JVMState* ejvms = NULL;
1882   if (has_exceptions()) {
1883     ejvms = transfer_exceptions_into_jvms();
1884   }
1885 
1886   ReplacedNodes replaced_nodes = map()->replaced_nodes();
1887   ReplacedNodes replaced_nodes_exception;
1888   Node* ex_ctl = top();
1889 
1890   SafePointNode* final_state = stop();
1891 
1892   // Find all the needed outputs of this call
1893   CallProjections callprojs;
1894   call->extract_projections(&callprojs, true);
1895 
1896   Node* init_mem = call->in(TypeFunc::Memory);
1897   Node* final_mem = final_state->in(TypeFunc::Memory);
1898   Node* final_ctl = final_state->in(TypeFunc::Control);
1899   Node* final_io = final_state->in(TypeFunc::I_O);
1900 
1901   // Replace all the old call edges with the edges from the inlining result
1902   if (callprojs.fallthrough_catchproj != NULL) {
1903     C->gvn_replace_by(callprojs.fallthrough_catchproj, final_ctl);
1904   }
1905   if (callprojs.fallthrough_memproj != NULL) {
1906     if (final_mem->is_MergeMem()) {
1907       // Parser's exits MergeMem was not transformed but may be optimized
1908       final_mem = _gvn.transform(final_mem);
1909     }
1910     C->gvn_replace_by(callprojs.fallthrough_memproj,   final_mem);
1911   }
1912   if (callprojs.fallthrough_ioproj != NULL) {
1913     C->gvn_replace_by(callprojs.fallthrough_ioproj,    final_io);
1914   }
1915 
1916   // Replace the result with the new result if it exists and is used
1917   if (callprojs.resproj != NULL && result != NULL) {
1918     C->gvn_replace_by(callprojs.resproj, result);
1919   }
1920 
1921   if (ejvms == NULL) {
1922     // No exception edges to simply kill off those paths
1923     if (callprojs.catchall_catchproj != NULL) {
1924       C->gvn_replace_by(callprojs.catchall_catchproj, C->top());
1925     }
1926     if (callprojs.catchall_memproj != NULL) {
1927       C->gvn_replace_by(callprojs.catchall_memproj,   C->top());
1928     }
1929     if (callprojs.catchall_ioproj != NULL) {
1930       C->gvn_replace_by(callprojs.catchall_ioproj,    C->top());
1931     }
1932     // Replace the old exception object with top
1933     if (callprojs.exobj != NULL) {
1934       C->gvn_replace_by(callprojs.exobj, C->top());
1935     }
1936   } else {
1937     GraphKit ekit(ejvms);
1938 
1939     // Load my combined exception state into the kit, with all phis transformed:
1940     SafePointNode* ex_map = ekit.combine_and_pop_all_exception_states();
1941     replaced_nodes_exception = ex_map->replaced_nodes();
1942 
1943     Node* ex_oop = ekit.use_exception_state(ex_map);
1944 
1945     if (callprojs.catchall_catchproj != NULL) {
1946       C->gvn_replace_by(callprojs.catchall_catchproj, ekit.control());
1947       ex_ctl = ekit.control();
1948     }
1949     if (callprojs.catchall_memproj != NULL) {
1950       C->gvn_replace_by(callprojs.catchall_memproj,   ekit.reset_memory());
1951     }
1952     if (callprojs.catchall_ioproj != NULL) {
1953       C->gvn_replace_by(callprojs.catchall_ioproj,    ekit.i_o());
1954     }
1955 
1956     // Replace the old exception object with the newly created one
1957     if (callprojs.exobj != NULL) {
1958       C->gvn_replace_by(callprojs.exobj, ex_oop);
1959     }
1960   }
1961 
1962   // Disconnect the call from the graph
1963   call->disconnect_inputs(NULL, C);
1964   C->gvn_replace_by(call, C->top());
1965 
1966   // Clean up any MergeMems that feed other MergeMems since the
1967   // optimizer doesn't like that.
1968   if (final_mem->is_MergeMem()) {
1969     Node_List wl;
1970     for (SimpleDUIterator i(final_mem); i.has_next(); i.next()) {
1971       Node* m = i.get();
1972       if (m->is_MergeMem() && !wl.contains(m)) {
1973         wl.push(m);
1974       }
1975     }
1976     while (wl.size()  > 0) {
1977       _gvn.transform(wl.pop());
1978     }
1979   }
1980 
1981   if (callprojs.fallthrough_catchproj != NULL && !final_ctl->is_top() && do_replaced_nodes) {
1982     replaced_nodes.apply(C, final_ctl);
1983   }
1984   if (!ex_ctl->is_top() && do_replaced_nodes) {
1985     replaced_nodes_exception.apply(C, ex_ctl);
1986   }
1987 }
1988 
1989 
1990 //------------------------------increment_counter------------------------------
1991 // for statistics: increment a VM counter by 1
1992 
1993 void GraphKit::increment_counter(address counter_addr) {
1994   Node* adr1 = makecon(TypeRawPtr::make(counter_addr));
1995   increment_counter(adr1);
1996 }
1997 
1998 void GraphKit::increment_counter(Node* counter_addr) {
1999   int adr_type = Compile::AliasIdxRaw;
2000   Node* ctrl = control();
2001   Node* cnt  = make_load(ctrl, counter_addr, TypeInt::INT, T_INT, adr_type, MemNode::unordered);
2002   Node* incr = _gvn.transform(new AddINode(cnt, _gvn.intcon(1)));
2003   store_to_memory(ctrl, counter_addr, incr, T_INT, adr_type, MemNode::unordered);
2004 }
2005 
2006 
2007 //------------------------------uncommon_trap----------------------------------
2008 // Bail out to the interpreter in mid-method.  Implemented by calling the
2009 // uncommon_trap blob.  This helper function inserts a runtime call with the
2010 // right debug info.
2011 void GraphKit::uncommon_trap(int trap_request,
2012                              ciKlass* klass, const char* comment,
2013                              bool must_throw,
2014                              bool keep_exact_action) {
2015   if (failing())  stop();
2016   if (stopped())  return; // trap reachable?
2017 
2018   // Note:  If ProfileTraps is true, and if a deopt. actually
2019   // occurs here, the runtime will make sure an MDO exists.  There is
2020   // no need to call method()->ensure_method_data() at this point.
2021 
2022   // Set the stack pointer to the right value for reexecution:
2023   set_sp(reexecute_sp());
2024 
2025 #ifdef ASSERT
2026   if (!must_throw) {
2027     // Make sure the stack has at least enough depth to execute
2028     // the current bytecode.
2029     int inputs, ignored_depth;
2030     if (compute_stack_effects(inputs, ignored_depth)) {
2031       assert(sp() >= inputs, "must have enough JVMS stack to execute %s: sp=%d, inputs=%d",
2032              Bytecodes::name(java_bc()), sp(), inputs);
2033     }
2034   }
2035 #endif
2036 
2037   Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(trap_request);
2038   Deoptimization::DeoptAction action = Deoptimization::trap_request_action(trap_request);
2039 
2040   switch (action) {
2041   case Deoptimization::Action_maybe_recompile:
2042   case Deoptimization::Action_reinterpret:
2043     // Temporary fix for 6529811 to allow virtual calls to be sure they
2044     // get the chance to go from mono->bi->mega
2045     if (!keep_exact_action &&
2046         Deoptimization::trap_request_index(trap_request) < 0 &&
2047         too_many_recompiles(reason)) {
2048       // This BCI is causing too many recompilations.
2049       if (C->log() != NULL) {
2050         C->log()->elem("observe that='trap_action_change' reason='%s' from='%s' to='none'",
2051                 Deoptimization::trap_reason_name(reason),
2052                 Deoptimization::trap_action_name(action));
2053       }
2054       action = Deoptimization::Action_none;
2055       trap_request = Deoptimization::make_trap_request(reason, action);
2056     } else {
2057       C->set_trap_can_recompile(true);
2058     }
2059     break;
2060   case Deoptimization::Action_make_not_entrant:
2061     C->set_trap_can_recompile(true);
2062     break;
2063 #ifdef ASSERT
2064   case Deoptimization::Action_none:
2065   case Deoptimization::Action_make_not_compilable:
2066     break;
2067   default:
2068     fatal("unknown action %d: %s", action, Deoptimization::trap_action_name(action));
2069     break;
2070 #endif
2071   }
2072 
2073   if (TraceOptoParse) {
2074     char buf[100];
2075     tty->print_cr("Uncommon trap %s at bci:%d",
2076                   Deoptimization::format_trap_request(buf, sizeof(buf),
2077                                                       trap_request), bci());
2078   }
2079 
2080   CompileLog* log = C->log();
2081   if (log != NULL) {
2082     int kid = (klass == NULL)? -1: log->identify(klass);
2083     log->begin_elem("uncommon_trap bci='%d'", bci());
2084     char buf[100];
2085     log->print(" %s", Deoptimization::format_trap_request(buf, sizeof(buf),
2086                                                           trap_request));
2087     if (kid >= 0)         log->print(" klass='%d'", kid);
2088     if (comment != NULL)  log->print(" comment='%s'", comment);
2089     log->end_elem();
2090   }
2091 
2092   // Make sure any guarding test views this path as very unlikely
2093   Node *i0 = control()->in(0);
2094   if (i0 != NULL && i0->is_If()) {        // Found a guarding if test?
2095     IfNode *iff = i0->as_If();
2096     float f = iff->_prob;   // Get prob
2097     if (control()->Opcode() == Op_IfTrue) {
2098       if (f > PROB_UNLIKELY_MAG(4))
2099         iff->_prob = PROB_MIN;
2100     } else {
2101       if (f < PROB_LIKELY_MAG(4))
2102         iff->_prob = PROB_MAX;
2103     }
2104   }
2105 
2106   // Clear out dead values from the debug info.
2107   kill_dead_locals();
2108 
2109   // Now insert the uncommon trap subroutine call
2110   address call_addr = SharedRuntime::uncommon_trap_blob()->entry_point();
2111   const TypePtr* no_memory_effects = NULL;
2112   // Pass the index of the class to be loaded
2113   Node* call = make_runtime_call(RC_NO_LEAF | RC_UNCOMMON |
2114                                  (must_throw ? RC_MUST_THROW : 0),
2115                                  OptoRuntime::uncommon_trap_Type(),
2116                                  call_addr, "uncommon_trap", no_memory_effects,
2117                                  intcon(trap_request));
2118   assert(call->as_CallStaticJava()->uncommon_trap_request() == trap_request,
2119          "must extract request correctly from the graph");
2120   assert(trap_request != 0, "zero value reserved by uncommon_trap_request");
2121 
2122   call->set_req(TypeFunc::ReturnAdr, returnadr());
2123   // The debug info is the only real input to this call.
2124 
2125   // Halt-and-catch fire here.  The above call should never return!
2126   HaltNode* halt = new HaltNode(control(), frameptr());
2127   _gvn.set_type_bottom(halt);
2128   root()->add_req(halt);
2129 
2130   stop_and_kill_map();
2131 }
2132 
2133 
2134 //--------------------------just_allocated_object------------------------------
2135 // Report the object that was just allocated.
2136 // It must be the case that there are no intervening safepoints.
2137 // We use this to determine if an object is so "fresh" that
2138 // it does not require card marks.
2139 Node* GraphKit::just_allocated_object(Node* current_control) {
2140   if (C->recent_alloc_ctl() == current_control)
2141     return C->recent_alloc_obj();
2142   return NULL;
2143 }
2144 
2145 
2146 void GraphKit::round_double_arguments(ciMethod* dest_method) {
2147   // (Note:  TypeFunc::make has a cache that makes this fast.)
2148   const TypeFunc* tf    = TypeFunc::make(dest_method);
2149   int             nargs = tf->domain_sig()->cnt() - TypeFunc::Parms;
2150   for (int j = 0; j < nargs; j++) {
2151     const Type *targ = tf->domain_sig()->field_at(j + TypeFunc::Parms);
2152     if( targ->basic_type() == T_DOUBLE ) {
2153       // If any parameters are doubles, they must be rounded before
2154       // the call, dstore_rounding does gvn.transform
2155       Node *arg = argument(j);
2156       arg = dstore_rounding(arg);
2157       set_argument(j, arg);
2158     }
2159   }
2160 }
2161 
2162 /**
2163  * Record profiling data exact_kls for Node n with the type system so
2164  * that it can propagate it (speculation)
2165  *
2166  * @param n          node that the type applies to
2167  * @param exact_kls  type from profiling
2168  * @param maybe_null did profiling see null?
2169  *
2170  * @return           node with improved type
2171  */
2172 Node* GraphKit::record_profile_for_speculation(Node* n, ciKlass* exact_kls, bool maybe_null) {
2173   const Type* current_type = _gvn.type(n);
2174   assert(UseTypeSpeculation, "type speculation must be on");
2175 
2176   const TypePtr* speculative = current_type->speculative();
2177 
2178   // Should the klass from the profile be recorded in the speculative type?
2179   if (current_type->would_improve_type(exact_kls, jvms()->depth())) {
2180     const TypeKlassPtr* tklass = TypeKlassPtr::make(exact_kls);
2181     const TypeOopPtr* xtype = tklass->as_instance_type();
2182     assert(xtype->klass_is_exact(), "Should be exact");
2183     // Any reason to believe n is not null (from this profiling or a previous one)?
2184     const TypePtr* ptr = (maybe_null && current_type->speculative_maybe_null()) ? TypePtr::BOTTOM : TypePtr::NOTNULL;
2185     // record the new speculative type's depth
2186     speculative = xtype->cast_to_ptr_type(ptr->ptr())->is_ptr();
2187     speculative = speculative->with_inline_depth(jvms()->depth());
2188   } else if (current_type->would_improve_ptr(maybe_null)) {
2189     // Profiling report that null was never seen so we can change the
2190     // speculative type to non null ptr.
2191     assert(!maybe_null, "nothing to improve");
2192     if (speculative == NULL) {
2193       speculative = TypePtr::NOTNULL;
2194     } else {
2195       const TypePtr* ptr = TypePtr::NOTNULL;
2196       speculative = speculative->cast_to_ptr_type(ptr->ptr())->is_ptr();
2197     }
2198   }
2199 
2200   if (speculative != current_type->speculative()) {
2201     // Build a type with a speculative type (what we think we know
2202     // about the type but will need a guard when we use it)
2203     const TypeOopPtr* spec_type = TypeOopPtr::make(TypePtr::BotPTR, Type::Offset::bottom, TypeOopPtr::InstanceBot, speculative);
2204     // We're changing the type, we need a new CheckCast node to carry
2205     // the new type. The new type depends on the control: what
2206     // profiling tells us is only valid from here as far as we can
2207     // tell.
2208     Node* cast = new CheckCastPPNode(control(), n, current_type->remove_speculative()->join_speculative(spec_type));
2209     cast = _gvn.transform(cast);
2210     replace_in_map(n, cast);
2211     n = cast;
2212   }
2213 
2214   return n;
2215 }
2216 
2217 /**
2218  * Record profiling data from receiver profiling at an invoke with the
2219  * type system so that it can propagate it (speculation)
2220  *
2221  * @param n  receiver node
2222  *
2223  * @return   node with improved type
2224  */
2225 Node* GraphKit::record_profiled_receiver_for_speculation(Node* n) {
2226   if (!UseTypeSpeculation) {
2227     return n;
2228   }
2229   ciKlass* exact_kls = profile_has_unique_klass();
2230   bool maybe_null = true;
2231   if (java_bc() == Bytecodes::_checkcast ||
2232       java_bc() == Bytecodes::_instanceof ||
2233       java_bc() == Bytecodes::_aastore) {
2234     ciProfileData* data = method()->method_data()->bci_to_data(bci());
2235     bool maybe_null = data == NULL ? true : data->as_BitData()->null_seen();
2236   }
2237   return record_profile_for_speculation(n, exact_kls, maybe_null);
2238   return n;
2239 }
2240 
2241 /**
2242  * Record profiling data from argument profiling at an invoke with the
2243  * type system so that it can propagate it (speculation)
2244  *
2245  * @param dest_method  target method for the call
2246  * @param bc           what invoke bytecode is this?
2247  */
2248 void GraphKit::record_profiled_arguments_for_speculation(ciMethod* dest_method, Bytecodes::Code bc) {
2249   if (!UseTypeSpeculation) {
2250     return;
2251   }
2252   const TypeFunc* tf    = TypeFunc::make(dest_method);
2253   int             nargs = tf->domain_sig()->cnt() - TypeFunc::Parms;
2254   int skip = Bytecodes::has_receiver(bc) ? 1 : 0;
2255   for (int j = skip, i = 0; j < nargs && i < TypeProfileArgsLimit; j++) {
2256     const Type *targ = tf->domain_sig()->field_at(j + TypeFunc::Parms);
2257     if (targ->basic_type() == T_OBJECT || targ->basic_type() == T_ARRAY) {
2258       bool maybe_null = true;
2259       ciKlass* better_type = NULL;
2260       if (method()->argument_profiled_type(bci(), i, better_type, maybe_null)) {
2261         record_profile_for_speculation(argument(j), better_type, maybe_null);
2262       }
2263       i++;
2264     }
2265   }
2266 }
2267 
2268 /**
2269  * Record profiling data from parameter profiling at an invoke with
2270  * the type system so that it can propagate it (speculation)
2271  */
2272 void GraphKit::record_profiled_parameters_for_speculation() {
2273   if (!UseTypeSpeculation) {
2274     return;
2275   }
2276   for (int i = 0, j = 0; i < method()->arg_size() ; i++) {
2277     if (_gvn.type(local(i))->isa_oopptr()) {
2278       bool maybe_null = true;
2279       ciKlass* better_type = NULL;
2280       if (method()->parameter_profiled_type(j, better_type, maybe_null)) {
2281         record_profile_for_speculation(local(i), better_type, maybe_null);
2282       }
2283       j++;
2284     }
2285   }
2286 }
2287 
2288 /**
2289  * Record profiling data from return value profiling at an invoke with
2290  * the type system so that it can propagate it (speculation)
2291  */
2292 void GraphKit::record_profiled_return_for_speculation() {
2293   if (!UseTypeSpeculation) {
2294     return;
2295   }
2296   bool maybe_null = true;
2297   ciKlass* better_type = NULL;
2298   if (method()->return_profiled_type(bci(), better_type, maybe_null)) {
2299     // If profiling reports a single type for the return value,
2300     // feed it to the type system so it can propagate it as a
2301     // speculative type
2302     record_profile_for_speculation(stack(sp()-1), better_type, maybe_null);
2303   }
2304 }
2305 
2306 void GraphKit::round_double_result(ciMethod* dest_method) {
2307   // A non-strict method may return a double value which has an extended
2308   // exponent, but this must not be visible in a caller which is 'strict'
2309   // If a strict caller invokes a non-strict callee, round a double result
2310 
2311   BasicType result_type = dest_method->return_type()->basic_type();
2312   assert( method() != NULL, "must have caller context");
2313   if( result_type == T_DOUBLE && method()->is_strict() && !dest_method->is_strict() ) {
2314     // Destination method's return value is on top of stack
2315     // dstore_rounding() does gvn.transform
2316     Node *result = pop_pair();
2317     result = dstore_rounding(result);
2318     push_pair(result);
2319   }
2320 }
2321 
2322 // rounding for strict float precision conformance
2323 Node* GraphKit::precision_rounding(Node* n) {
2324   return UseStrictFP && _method->flags().is_strict()
2325     && UseSSE == 0 && Matcher::strict_fp_requires_explicit_rounding
2326     ? _gvn.transform( new RoundFloatNode(0, n) )
2327     : n;
2328 }
2329 
2330 // rounding for strict double precision conformance
2331 Node* GraphKit::dprecision_rounding(Node *n) {
2332   return UseStrictFP && _method->flags().is_strict()
2333     && UseSSE <= 1 && Matcher::strict_fp_requires_explicit_rounding
2334     ? _gvn.transform( new RoundDoubleNode(0, n) )
2335     : n;
2336 }
2337 
2338 // rounding for non-strict double stores
2339 Node* GraphKit::dstore_rounding(Node* n) {
2340   return Matcher::strict_fp_requires_explicit_rounding
2341     && UseSSE <= 1
2342     ? _gvn.transform( new RoundDoubleNode(0, n) )
2343     : n;
2344 }
2345 
2346 //=============================================================================
2347 // Generate a fast path/slow path idiom.  Graph looks like:
2348 // [foo] indicates that 'foo' is a parameter
2349 //
2350 //              [in]     NULL
2351 //                 \    /
2352 //                  CmpP
2353 //                  Bool ne
2354 //                   If
2355 //                  /  \
2356 //              True    False-<2>
2357 //              / |
2358 //             /  cast_not_null
2359 //           Load  |    |   ^
2360 //        [fast_test]   |   |
2361 // gvn to   opt_test    |   |
2362 //          /    \      |  <1>
2363 //      True     False  |
2364 //        |         \\  |
2365 //   [slow_call]     \[fast_result]
2366 //    Ctl   Val       \      \
2367 //     |               \      \
2368 //    Catch       <1>   \      \
2369 //   /    \        ^     \      \
2370 //  Ex    No_Ex    |      \      \
2371 //  |       \   \  |       \ <2>  \
2372 //  ...      \  [slow_res] |  |    \   [null_result]
2373 //            \         \--+--+---  |  |
2374 //             \           | /    \ | /
2375 //              --------Region     Phi
2376 //
2377 //=============================================================================
2378 // Code is structured as a series of driver functions all called 'do_XXX' that
2379 // call a set of helper functions.  Helper functions first, then drivers.
2380 
2381 //------------------------------null_check_oop---------------------------------
2382 // Null check oop.  Set null-path control into Region in slot 3.
2383 // Make a cast-not-nullness use the other not-null control.  Return cast.
2384 Node* GraphKit::null_check_oop(Node* value, Node* *null_control,
2385                                bool never_see_null,
2386                                bool safe_for_replace,
2387                                bool speculative) {
2388   // Initial NULL check taken path
2389   (*null_control) = top();
2390   Node* cast = null_check_common(value, T_OBJECT, false, null_control, speculative);
2391 
2392   // Generate uncommon_trap:
2393   if (never_see_null && (*null_control) != top()) {
2394     // If we see an unexpected null at a check-cast we record it and force a
2395     // recompile; the offending check-cast will be compiled to handle NULLs.
2396     // If we see more than one offending BCI, then all checkcasts in the
2397     // method will be compiled to handle NULLs.
2398     PreserveJVMState pjvms(this);
2399     set_control(*null_control);
2400     replace_in_map(value, null());
2401     Deoptimization::DeoptReason reason = Deoptimization::reason_null_check(speculative);
2402     uncommon_trap(reason,
2403                   Deoptimization::Action_make_not_entrant);
2404     (*null_control) = top();    // NULL path is dead
2405   }
2406   if ((*null_control) == top() && safe_for_replace) {
2407     replace_in_map(value, cast);
2408   }
2409 
2410   // Cast away null-ness on the result
2411   return cast;
2412 }
2413 
2414 //------------------------------opt_iff----------------------------------------
2415 // Optimize the fast-check IfNode.  Set the fast-path region slot 2.
2416 // Return slow-path control.
2417 Node* GraphKit::opt_iff(Node* region, Node* iff) {
2418   IfNode *opt_iff = _gvn.transform(iff)->as_If();
2419 
2420   // Fast path taken; set region slot 2
2421   Node *fast_taken = _gvn.transform( new IfFalseNode(opt_iff) );
2422   region->init_req(2,fast_taken); // Capture fast-control
2423 
2424   // Fast path not-taken, i.e. slow path
2425   Node *slow_taken = _gvn.transform( new IfTrueNode(opt_iff) );
2426   return slow_taken;
2427 }
2428 
2429 //-----------------------------make_runtime_call-------------------------------
2430 Node* GraphKit::make_runtime_call(int flags,
2431                                   const TypeFunc* call_type, address call_addr,
2432                                   const char* call_name,
2433                                   const TypePtr* adr_type,
2434                                   // The following parms are all optional.
2435                                   // The first NULL ends the list.
2436                                   Node* parm0, Node* parm1,
2437                                   Node* parm2, Node* parm3,
2438                                   Node* parm4, Node* parm5,
2439                                   Node* parm6, Node* parm7) {
2440   // Slow-path call
2441   bool is_leaf = !(flags & RC_NO_LEAF);
2442   bool has_io  = (!is_leaf && !(flags & RC_NO_IO));
2443   if (call_name == NULL) {
2444     assert(!is_leaf, "must supply name for leaf");
2445     call_name = OptoRuntime::stub_name(call_addr);
2446   }
2447   CallNode* call;
2448   if (!is_leaf) {
2449     call = new CallStaticJavaNode(call_type, call_addr, call_name,
2450                                            bci(), adr_type);
2451   } else if (flags & RC_NO_FP) {
2452     call = new CallLeafNoFPNode(call_type, call_addr, call_name, adr_type);
2453   } else {
2454     call = new CallLeafNode(call_type, call_addr, call_name, adr_type);
2455   }
2456 
2457   // The following is similar to set_edges_for_java_call,
2458   // except that the memory effects of the call are restricted to AliasIdxRaw.
2459 
2460   // Slow path call has no side-effects, uses few values
2461   bool wide_in  = !(flags & RC_NARROW_MEM);
2462   bool wide_out = (C->get_alias_index(adr_type) == Compile::AliasIdxBot);
2463 
2464   Node* prev_mem = NULL;
2465   if (wide_in) {
2466     prev_mem = set_predefined_input_for_runtime_call(call);
2467   } else {
2468     assert(!wide_out, "narrow in => narrow out");
2469     Node* narrow_mem = memory(adr_type);
2470     prev_mem = reset_memory();
2471     map()->set_memory(narrow_mem);
2472     set_predefined_input_for_runtime_call(call);
2473   }
2474 
2475   // Hook each parm in order.  Stop looking at the first NULL.
2476   if (parm0 != NULL) { call->init_req(TypeFunc::Parms+0, parm0);
2477   if (parm1 != NULL) { call->init_req(TypeFunc::Parms+1, parm1);
2478   if (parm2 != NULL) { call->init_req(TypeFunc::Parms+2, parm2);
2479   if (parm3 != NULL) { call->init_req(TypeFunc::Parms+3, parm3);
2480   if (parm4 != NULL) { call->init_req(TypeFunc::Parms+4, parm4);
2481   if (parm5 != NULL) { call->init_req(TypeFunc::Parms+5, parm5);
2482   if (parm6 != NULL) { call->init_req(TypeFunc::Parms+6, parm6);
2483   if (parm7 != NULL) { call->init_req(TypeFunc::Parms+7, parm7);
2484     /* close each nested if ===> */  } } } } } } } }
2485   assert(call->in(call->req()-1) != NULL, "must initialize all parms");
2486 
2487   if (!is_leaf) {
2488     // Non-leaves can block and take safepoints:
2489     add_safepoint_edges(call, ((flags & RC_MUST_THROW) != 0));
2490   }
2491   // Non-leaves can throw exceptions:
2492   if (has_io) {
2493     call->set_req(TypeFunc::I_O, i_o());
2494   }
2495 
2496   if (flags & RC_UNCOMMON) {
2497     // Set the count to a tiny probability.  Cf. Estimate_Block_Frequency.
2498     // (An "if" probability corresponds roughly to an unconditional count.
2499     // Sort of.)
2500     call->set_cnt(PROB_UNLIKELY_MAG(4));
2501   }
2502 
2503   Node* c = _gvn.transform(call);
2504   assert(c == call, "cannot disappear");
2505 
2506   if (wide_out) {
2507     // Slow path call has full side-effects.
2508     set_predefined_output_for_runtime_call(call);
2509   } else {
2510     // Slow path call has few side-effects, and/or sets few values.
2511     set_predefined_output_for_runtime_call(call, prev_mem, adr_type);
2512   }
2513 
2514   if (has_io) {
2515     set_i_o(_gvn.transform(new ProjNode(call, TypeFunc::I_O)));
2516   }
2517   return call;
2518 
2519 }
2520 
2521 //------------------------------merge_memory-----------------------------------
2522 // Merge memory from one path into the current memory state.
2523 void GraphKit::merge_memory(Node* new_mem, Node* region, int new_path) {
2524   for (MergeMemStream mms(merged_memory(), new_mem->as_MergeMem()); mms.next_non_empty2(); ) {
2525     Node* old_slice = mms.force_memory();
2526     Node* new_slice = mms.memory2();
2527     if (old_slice != new_slice) {
2528       PhiNode* phi;
2529       if (old_slice->is_Phi() && old_slice->as_Phi()->region() == region) {
2530         if (mms.is_empty()) {
2531           // clone base memory Phi's inputs for this memory slice
2532           assert(old_slice == mms.base_memory(), "sanity");
2533           phi = PhiNode::make(region, NULL, Type::MEMORY, mms.adr_type(C));
2534           _gvn.set_type(phi, Type::MEMORY);
2535           for (uint i = 1; i < phi->req(); i++) {
2536             phi->init_req(i, old_slice->in(i));
2537           }
2538         } else {
2539           phi = old_slice->as_Phi(); // Phi was generated already
2540         }
2541       } else {
2542         phi = PhiNode::make(region, old_slice, Type::MEMORY, mms.adr_type(C));
2543         _gvn.set_type(phi, Type::MEMORY);
2544       }
2545       phi->set_req(new_path, new_slice);
2546       mms.set_memory(phi);
2547     }
2548   }
2549 }
2550 
2551 //------------------------------make_slow_call_ex------------------------------
2552 // Make the exception handler hookups for the slow call
2553 void GraphKit::make_slow_call_ex(Node* call, ciInstanceKlass* ex_klass, bool separate_io_proj, bool deoptimize) {
2554   if (stopped())  return;
2555 
2556   // Make a catch node with just two handlers:  fall-through and catch-all
2557   Node* i_o  = _gvn.transform( new ProjNode(call, TypeFunc::I_O, separate_io_proj) );
2558   Node* catc = _gvn.transform( new CatchNode(control(), i_o, 2) );
2559   Node* norm = _gvn.transform( new CatchProjNode(catc, CatchProjNode::fall_through_index, CatchProjNode::no_handler_bci) );
2560   Node* excp = _gvn.transform( new CatchProjNode(catc, CatchProjNode::catch_all_index,    CatchProjNode::no_handler_bci) );
2561 
2562   { PreserveJVMState pjvms(this);
2563     set_control(excp);
2564     set_i_o(i_o);
2565 
2566     if (excp != top()) {
2567       if (deoptimize) {
2568         // Deoptimize if an exception is caught. Don't construct exception state in this case.
2569         uncommon_trap(Deoptimization::Reason_unhandled,
2570                       Deoptimization::Action_none);
2571       } else {
2572         // Create an exception state also.
2573         // Use an exact type if the caller has specified a specific exception.
2574         const Type* ex_type = TypeOopPtr::make_from_klass_unique(ex_klass)->cast_to_ptr_type(TypePtr::NotNull);
2575         Node*       ex_oop  = new CreateExNode(ex_type, control(), i_o);
2576         add_exception_state(make_exception_state(_gvn.transform(ex_oop)));
2577       }
2578     }
2579   }
2580 
2581   // Get the no-exception control from the CatchNode.
2582   set_control(norm);
2583 }
2584 
2585 static IfNode* gen_subtype_check_compare(Node* ctrl, Node* in1, Node* in2, BoolTest::mask test, float p, PhaseGVN* gvn, BasicType bt) {
2586   Node* cmp = NULL;
2587   switch(bt) {
2588   case T_INT: cmp = new CmpINode(in1, in2); break;
2589   case T_ADDRESS: cmp = new CmpPNode(in1, in2); break;
2590   default: fatal("unexpected comparison type %s", type2name(bt));
2591   }
2592   gvn->transform(cmp);
2593   Node* bol = gvn->transform(new BoolNode(cmp, test));
2594   IfNode* iff = new IfNode(ctrl, bol, p, COUNT_UNKNOWN);
2595   gvn->transform(iff);
2596   if (!bol->is_Con()) gvn->record_for_igvn(iff);
2597   return iff;
2598 }
2599 
2600 
2601 //-------------------------------gen_subtype_check-----------------------------
2602 // Generate a subtyping check.  Takes as input the subtype and supertype.
2603 // Returns 2 values: sets the default control() to the true path and returns
2604 // the false path.  Only reads invariant memory; sets no (visible) memory.
2605 // The PartialSubtypeCheckNode sets the hidden 1-word cache in the encoding
2606 // but that's not exposed to the optimizer.  This call also doesn't take in an
2607 // Object; if you wish to check an Object you need to load the Object's class
2608 // prior to coming here.
2609 Node* Phase::gen_subtype_check(Node* subklass, Node* superklass, Node** ctrl, MergeMemNode* mem, PhaseGVN* gvn) {
2610   Compile* C = gvn->C;
2611 
2612   if ((*ctrl)->is_top()) {
2613     return C->top();
2614   }
2615 
2616   // Fast check for identical types, perhaps identical constants.
2617   // The types can even be identical non-constants, in cases
2618   // involving Array.newInstance, Object.clone, etc.
2619   if (subklass == superklass)
2620     return C->top();             // false path is dead; no test needed.
2621 
2622   if (gvn->type(superklass)->singleton()) {
2623     ciKlass* superk = gvn->type(superklass)->is_klassptr()->klass();
2624     ciKlass* subk   = gvn->type(subklass)->is_klassptr()->klass();
2625 
2626     // In the common case of an exact superklass, try to fold up the
2627     // test before generating code.  You may ask, why not just generate
2628     // the code and then let it fold up?  The answer is that the generated
2629     // code will necessarily include null checks, which do not always
2630     // completely fold away.  If they are also needless, then they turn
2631     // into a performance loss.  Example:
2632     //    Foo[] fa = blah(); Foo x = fa[0]; fa[1] = x;
2633     // Here, the type of 'fa' is often exact, so the store check
2634     // of fa[1]=x will fold up, without testing the nullness of x.
2635     switch (C->static_subtype_check(superk, subk)) {
2636     case Compile::SSC_always_false:
2637       {
2638         Node* always_fail = *ctrl;
2639         *ctrl = gvn->C->top();
2640         return always_fail;
2641       }
2642     case Compile::SSC_always_true:
2643       return C->top();
2644     case Compile::SSC_easy_test:
2645       {
2646         // Just do a direct pointer compare and be done.
2647         IfNode* iff = gen_subtype_check_compare(*ctrl, subklass, superklass, BoolTest::eq, PROB_STATIC_FREQUENT, gvn, T_ADDRESS);
2648         *ctrl = gvn->transform(new IfTrueNode(iff));
2649         return gvn->transform(new IfFalseNode(iff));
2650       }
2651     case Compile::SSC_full_test:
2652       break;
2653     default:
2654       ShouldNotReachHere();
2655     }
2656   }
2657 
2658   // %%% Possible further optimization:  Even if the superklass is not exact,
2659   // if the subklass is the unique subtype of the superklass, the check
2660   // will always succeed.  We could leave a dependency behind to ensure this.
2661 
2662   // First load the super-klass's check-offset
2663   Node *p1 = gvn->transform(new AddPNode(superklass, superklass, gvn->MakeConX(in_bytes(Klass::super_check_offset_offset()))));
2664   Node* m = mem->memory_at(C->get_alias_index(gvn->type(p1)->is_ptr()));
2665   Node *chk_off = gvn->transform(new LoadINode(NULL, m, p1, gvn->type(p1)->is_ptr(), TypeInt::INT, MemNode::unordered));
2666   int cacheoff_con = in_bytes(Klass::secondary_super_cache_offset());
2667   bool might_be_cache = (gvn->find_int_con(chk_off, cacheoff_con) == cacheoff_con);
2668 
2669   // Load from the sub-klass's super-class display list, or a 1-word cache of
2670   // the secondary superclass list, or a failing value with a sentinel offset
2671   // if the super-klass is an interface or exceptionally deep in the Java
2672   // hierarchy and we have to scan the secondary superclass list the hard way.
2673   // Worst-case type is a little odd: NULL is allowed as a result (usually
2674   // klass loads can never produce a NULL).
2675   Node *chk_off_X = chk_off;
2676 #ifdef _LP64
2677   chk_off_X = gvn->transform(new ConvI2LNode(chk_off_X));
2678 #endif
2679   Node *p2 = gvn->transform(new AddPNode(subklass,subklass,chk_off_X));
2680   // For some types like interfaces the following loadKlass is from a 1-word
2681   // cache which is mutable so can't use immutable memory.  Other
2682   // types load from the super-class display table which is immutable.
2683   m = mem->memory_at(C->get_alias_index(gvn->type(p2)->is_ptr()));
2684   Node *kmem = might_be_cache ? m : C->immutable_memory();
2685   Node *nkls = gvn->transform(LoadKlassNode::make(*gvn, NULL, kmem, p2, gvn->type(p2)->is_ptr(), TypeKlassPtr::OBJECT_OR_NULL));
2686 
2687   // Compile speed common case: ARE a subtype and we canNOT fail
2688   if( superklass == nkls )
2689     return C->top();             // false path is dead; no test needed.
2690 
2691   // See if we get an immediate positive hit.  Happens roughly 83% of the
2692   // time.  Test to see if the value loaded just previously from the subklass
2693   // is exactly the superklass.
2694   IfNode *iff1 = gen_subtype_check_compare(*ctrl, superklass, nkls, BoolTest::eq, PROB_LIKELY(0.83f), gvn, T_ADDRESS);
2695   Node *iftrue1 = gvn->transform( new IfTrueNode (iff1));
2696   *ctrl = gvn->transform(new IfFalseNode(iff1));
2697 
2698   // Compile speed common case: Check for being deterministic right now.  If
2699   // chk_off is a constant and not equal to cacheoff then we are NOT a
2700   // subklass.  In this case we need exactly the 1 test above and we can
2701   // return those results immediately.
2702   if (!might_be_cache) {
2703     Node* not_subtype_ctrl = *ctrl;
2704     *ctrl = iftrue1; // We need exactly the 1 test above
2705     return not_subtype_ctrl;
2706   }
2707 
2708   // Gather the various success & failures here
2709   RegionNode *r_ok_subtype = new RegionNode(4);
2710   gvn->record_for_igvn(r_ok_subtype);
2711   RegionNode *r_not_subtype = new RegionNode(3);
2712   gvn->record_for_igvn(r_not_subtype);
2713 
2714   r_ok_subtype->init_req(1, iftrue1);
2715 
2716   // Check for immediate negative hit.  Happens roughly 11% of the time (which
2717   // is roughly 63% of the remaining cases).  Test to see if the loaded
2718   // check-offset points into the subklass display list or the 1-element
2719   // cache.  If it points to the display (and NOT the cache) and the display
2720   // missed then it's not a subtype.
2721   Node *cacheoff = gvn->intcon(cacheoff_con);
2722   IfNode *iff2 = gen_subtype_check_compare(*ctrl, chk_off, cacheoff, BoolTest::ne, PROB_LIKELY(0.63f), gvn, T_INT);
2723   r_not_subtype->init_req(1, gvn->transform(new IfTrueNode (iff2)));
2724   *ctrl = gvn->transform(new IfFalseNode(iff2));
2725 
2726   // Check for self.  Very rare to get here, but it is taken 1/3 the time.
2727   // No performance impact (too rare) but allows sharing of secondary arrays
2728   // which has some footprint reduction.
2729   IfNode *iff3 = gen_subtype_check_compare(*ctrl, subklass, superklass, BoolTest::eq, PROB_LIKELY(0.36f), gvn, T_ADDRESS);
2730   r_ok_subtype->init_req(2, gvn->transform(new IfTrueNode(iff3)));
2731   *ctrl = gvn->transform(new IfFalseNode(iff3));
2732 
2733   // -- Roads not taken here: --
2734   // We could also have chosen to perform the self-check at the beginning
2735   // of this code sequence, as the assembler does.  This would not pay off
2736   // the same way, since the optimizer, unlike the assembler, can perform
2737   // static type analysis to fold away many successful self-checks.
2738   // Non-foldable self checks work better here in second position, because
2739   // the initial primary superclass check subsumes a self-check for most
2740   // types.  An exception would be a secondary type like array-of-interface,
2741   // which does not appear in its own primary supertype display.
2742   // Finally, we could have chosen to move the self-check into the
2743   // PartialSubtypeCheckNode, and from there out-of-line in a platform
2744   // dependent manner.  But it is worthwhile to have the check here,
2745   // where it can be perhaps be optimized.  The cost in code space is
2746   // small (register compare, branch).
2747 
2748   // Now do a linear scan of the secondary super-klass array.  Again, no real
2749   // performance impact (too rare) but it's gotta be done.
2750   // Since the code is rarely used, there is no penalty for moving it
2751   // out of line, and it can only improve I-cache density.
2752   // The decision to inline or out-of-line this final check is platform
2753   // dependent, and is found in the AD file definition of PartialSubtypeCheck.
2754   Node* psc = gvn->transform(
2755     new PartialSubtypeCheckNode(*ctrl, subklass, superklass));
2756 
2757   IfNode *iff4 = gen_subtype_check_compare(*ctrl, psc, gvn->zerocon(T_OBJECT), BoolTest::ne, PROB_FAIR, gvn, T_ADDRESS);
2758   r_not_subtype->init_req(2, gvn->transform(new IfTrueNode (iff4)));
2759   r_ok_subtype ->init_req(3, gvn->transform(new IfFalseNode(iff4)));
2760 
2761   // Return false path; set default control to true path.
2762   *ctrl = gvn->transform(r_ok_subtype);
2763   return gvn->transform(r_not_subtype);
2764 }
2765 
2766 // Profile-driven exact type check:
2767 Node* GraphKit::type_check_receiver(Node* receiver, ciKlass* klass,
2768                                     float prob,
2769                                     Node* *casted_receiver) {
2770   const TypeKlassPtr* tklass = TypeKlassPtr::make(klass);
2771   Node* recv_klass = load_object_klass(receiver);
2772   Node* want_klass = makecon(tklass);
2773   Node* cmp = _gvn.transform( new CmpPNode(recv_klass, want_klass) );
2774   Node* bol = _gvn.transform( new BoolNode(cmp, BoolTest::eq) );
2775   IfNode* iff = create_and_xform_if(control(), bol, prob, COUNT_UNKNOWN);
2776   set_control( _gvn.transform( new IfTrueNode (iff) ));
2777   Node* fail = _gvn.transform( new IfFalseNode(iff) );
2778 
2779   const TypeOopPtr* recv_xtype = tklass->as_instance_type();
2780   assert(recv_xtype->klass_is_exact(), "");
2781 
2782   // Subsume downstream occurrences of receiver with a cast to
2783   // recv_xtype, since now we know what the type will be.
2784   Node* cast = new CheckCastPPNode(control(), receiver, recv_xtype);
2785   (*casted_receiver) = _gvn.transform(cast);
2786   // (User must make the replace_in_map call.)
2787 
2788   return fail;
2789 }
2790 
2791 
2792 //------------------------------seems_never_null-------------------------------
2793 // Use null_seen information if it is available from the profile.
2794 // If we see an unexpected null at a type check we record it and force a
2795 // recompile; the offending check will be recompiled to handle NULLs.
2796 // If we see several offending BCIs, then all checks in the
2797 // method will be recompiled.
2798 bool GraphKit::seems_never_null(Node* obj, ciProfileData* data, bool& speculating) {
2799   speculating = !_gvn.type(obj)->speculative_maybe_null();
2800   Deoptimization::DeoptReason reason = Deoptimization::reason_null_check(speculating);
2801   if (UncommonNullCast               // Cutout for this technique
2802       && obj != null()               // And not the -Xcomp stupid case?
2803       && !too_many_traps(reason)
2804       ) {
2805     if (speculating) {
2806       return true;
2807     }
2808     if (data == NULL)
2809       // Edge case:  no mature data.  Be optimistic here.
2810       return true;
2811     // If the profile has not seen a null, assume it won't happen.
2812     assert(java_bc() == Bytecodes::_checkcast ||
2813            java_bc() == Bytecodes::_instanceof ||
2814            java_bc() == Bytecodes::_aastore, "MDO must collect null_seen bit here");
2815     return !data->as_BitData()->null_seen();
2816   }
2817   speculating = false;
2818   return false;
2819 }
2820 
2821 //------------------------maybe_cast_profiled_receiver-------------------------
2822 // If the profile has seen exactly one type, narrow to exactly that type.
2823 // Subsequent type checks will always fold up.
2824 Node* GraphKit::maybe_cast_profiled_receiver(Node* not_null_obj,
2825                                              ciKlass* require_klass,
2826                                              ciKlass* spec_klass,
2827                                              bool safe_for_replace) {
2828   if (!UseTypeProfile || !TypeProfileCasts) return NULL;
2829 
2830   Deoptimization::DeoptReason reason = Deoptimization::reason_class_check(spec_klass != NULL);
2831 
2832   // Make sure we haven't already deoptimized from this tactic.
2833   if (too_many_traps(reason) || too_many_recompiles(reason))
2834     return NULL;
2835 
2836   // (No, this isn't a call, but it's enough like a virtual call
2837   // to use the same ciMethod accessor to get the profile info...)
2838   // If we have a speculative type use it instead of profiling (which
2839   // may not help us)
2840   ciKlass* exact_kls = spec_klass == NULL ? profile_has_unique_klass() : spec_klass;
2841   if (exact_kls != NULL) {// no cast failures here
2842     if (require_klass == NULL ||
2843         C->static_subtype_check(require_klass, exact_kls) == Compile::SSC_always_true) {
2844       // If we narrow the type to match what the type profile sees or
2845       // the speculative type, we can then remove the rest of the
2846       // cast.
2847       // This is a win, even if the exact_kls is very specific,
2848       // because downstream operations, such as method calls,
2849       // will often benefit from the sharper type.
2850       Node* exact_obj = not_null_obj; // will get updated in place...
2851       Node* slow_ctl  = type_check_receiver(exact_obj, exact_kls, 1.0,
2852                                             &exact_obj);
2853       { PreserveJVMState pjvms(this);
2854         set_control(slow_ctl);
2855         uncommon_trap_exact(reason, Deoptimization::Action_maybe_recompile);
2856       }
2857       if (safe_for_replace) {
2858         replace_in_map(not_null_obj, exact_obj);
2859       }
2860       return exact_obj;
2861     }
2862     // assert(ssc == Compile::SSC_always_true)... except maybe the profile lied to us.
2863   }
2864 
2865   return NULL;
2866 }
2867 
2868 /**
2869  * Cast obj to type and emit guard unless we had too many traps here
2870  * already
2871  *
2872  * @param obj       node being casted
2873  * @param type      type to cast the node to
2874  * @param not_null  true if we know node cannot be null
2875  */
2876 Node* GraphKit::maybe_cast_profiled_obj(Node* obj,
2877                                         ciKlass* type,
2878                                         bool not_null) {
2879   if (stopped()) {
2880     return obj;
2881   }
2882 
2883   // type == NULL if profiling tells us this object is always null
2884   if (type != NULL) {
2885     Deoptimization::DeoptReason class_reason = Deoptimization::Reason_speculate_class_check;
2886     Deoptimization::DeoptReason null_reason = Deoptimization::Reason_speculate_null_check;
2887 
2888     if (!too_many_traps(null_reason) && !too_many_recompiles(null_reason) &&
2889         !too_many_traps(class_reason) &&
2890         !too_many_recompiles(class_reason)) {
2891       Node* not_null_obj = NULL;
2892       // not_null is true if we know the object is not null and
2893       // there's no need for a null check
2894       if (!not_null) {
2895         Node* null_ctl = top();
2896         not_null_obj = null_check_oop(obj, &null_ctl, true, true, true);
2897         assert(null_ctl->is_top(), "no null control here");
2898       } else {
2899         not_null_obj = obj;
2900       }
2901 
2902       Node* exact_obj = not_null_obj;
2903       ciKlass* exact_kls = type;
2904       Node* slow_ctl  = type_check_receiver(exact_obj, exact_kls, 1.0,
2905                                             &exact_obj);
2906       {
2907         PreserveJVMState pjvms(this);
2908         set_control(slow_ctl);
2909         uncommon_trap_exact(class_reason, Deoptimization::Action_maybe_recompile);
2910       }
2911       replace_in_map(not_null_obj, exact_obj);
2912       obj = exact_obj;
2913     }
2914   } else {
2915     if (!too_many_traps(Deoptimization::Reason_null_assert) &&
2916         !too_many_recompiles(Deoptimization::Reason_null_assert)) {
2917       Node* exact_obj = null_assert(obj);
2918       replace_in_map(obj, exact_obj);
2919       obj = exact_obj;
2920     }
2921   }
2922   return obj;
2923 }
2924 
2925 //-------------------------------gen_instanceof--------------------------------
2926 // Generate an instance-of idiom.  Used by both the instance-of bytecode
2927 // and the reflective instance-of call.
2928 Node* GraphKit::gen_instanceof(Node* obj, Node* superklass, bool safe_for_replace) {
2929   kill_dead_locals();           // Benefit all the uncommon traps
2930   assert( !stopped(), "dead parse path should be checked in callers" );
2931   assert(!TypePtr::NULL_PTR->higher_equal(_gvn.type(superklass)->is_klassptr()),
2932          "must check for not-null not-dead klass in callers");
2933 
2934   // Make the merge point
2935   enum { _obj_path = 1, _fail_path, _null_path, PATH_LIMIT };
2936   RegionNode* region = new RegionNode(PATH_LIMIT);
2937   Node*       phi    = new PhiNode(region, TypeInt::BOOL);
2938   C->set_has_split_ifs(true); // Has chance for split-if optimization
2939 
2940   ciProfileData* data = NULL;
2941   if (java_bc() == Bytecodes::_instanceof) {  // Only for the bytecode
2942     data = method()->method_data()->bci_to_data(bci());
2943   }
2944   bool speculative_not_null = false;
2945   bool never_see_null = (ProfileDynamicTypes  // aggressive use of profile
2946                          && seems_never_null(obj, data, speculative_not_null));
2947 
2948   // Null check; get casted pointer; set region slot 3
2949   Node* null_ctl = top();
2950   Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null, safe_for_replace, speculative_not_null);
2951 
2952   // If not_null_obj is dead, only null-path is taken
2953   if (stopped()) {              // Doing instance-of on a NULL?
2954     set_control(null_ctl);
2955     return intcon(0);
2956   }
2957   region->init_req(_null_path, null_ctl);
2958   phi   ->init_req(_null_path, intcon(0)); // Set null path value
2959   if (null_ctl == top()) {
2960     // Do this eagerly, so that pattern matches like is_diamond_phi
2961     // will work even during parsing.
2962     assert(_null_path == PATH_LIMIT-1, "delete last");
2963     region->del_req(_null_path);
2964     phi   ->del_req(_null_path);
2965   }
2966 
2967   // Do we know the type check always succeed?
2968   bool known_statically = false;
2969   if (_gvn.type(superklass)->singleton()) {
2970     ciKlass* superk = _gvn.type(superklass)->is_klassptr()->klass();
2971     ciKlass* subk = _gvn.type(obj)->is_oopptr()->klass();
2972     if (subk != NULL && subk->is_loaded()) {
2973       int static_res = C->static_subtype_check(superk, subk);
2974       known_statically = (static_res == Compile::SSC_always_true || static_res == Compile::SSC_always_false);
2975     }
2976   }
2977 
2978   if (known_statically && UseTypeSpeculation) {
2979     // If we know the type check always succeeds then we don't use the
2980     // profiling data at this bytecode. Don't lose it, feed it to the
2981     // type system as a speculative type.
2982     not_null_obj = record_profiled_receiver_for_speculation(not_null_obj);
2983   } else {
2984     const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
2985     // We may not have profiling here or it may not help us. If we
2986     // have a speculative type use it to perform an exact cast.
2987     ciKlass* spec_obj_type = obj_type->speculative_type();
2988     if (spec_obj_type != NULL || (ProfileDynamicTypes && data != NULL)) {
2989       Node* cast_obj = maybe_cast_profiled_receiver(not_null_obj, NULL, spec_obj_type, safe_for_replace);
2990       if (stopped()) {            // Profile disagrees with this path.
2991         set_control(null_ctl);    // Null is the only remaining possibility.
2992         return intcon(0);
2993       }
2994       if (cast_obj != NULL) {
2995         not_null_obj = cast_obj;
2996       }
2997     }
2998   }
2999 
3000   // Load the object's klass
3001   Node* obj_klass = load_object_klass(not_null_obj);
3002 
3003   // Generate the subtype check
3004   Node* not_subtype_ctrl = gen_subtype_check(obj_klass, superklass);
3005 
3006   // Plug in the success path to the general merge in slot 1.
3007   region->init_req(_obj_path, control());
3008   phi   ->init_req(_obj_path, intcon(1));
3009 
3010   // Plug in the failing path to the general merge in slot 2.
3011   region->init_req(_fail_path, not_subtype_ctrl);
3012   phi   ->init_req(_fail_path, intcon(0));
3013 
3014   // Return final merged results
3015   set_control( _gvn.transform(region) );
3016   record_for_igvn(region);
3017   return _gvn.transform(phi);
3018 }
3019 
3020 //-------------------------------gen_checkcast---------------------------------
3021 // Generate a checkcast idiom.  Used by both the checkcast bytecode and the
3022 // array store bytecode.  Stack must be as-if BEFORE doing the bytecode so the
3023 // uncommon-trap paths work.  Adjust stack after this call.
3024 // If failure_control is supplied and not null, it is filled in with
3025 // the control edge for the cast failure.  Otherwise, an appropriate
3026 // uncommon trap or exception is thrown.
3027 Node* GraphKit::gen_checkcast(Node *obj, Node* superklass,
3028                               Node* *failure_control) {
3029   kill_dead_locals();           // Benefit all the uncommon traps
3030   const TypeKlassPtr *tk = _gvn.type(superklass)->is_klassptr();
3031   const Type *toop = TypeOopPtr::make_from_klass(tk->klass());
3032 
3033   // Fast cutout:  Check the case that the cast is vacuously true.
3034   // This detects the common cases where the test will short-circuit
3035   // away completely.  We do this before we perform the null check,
3036   // because if the test is going to turn into zero code, we don't
3037   // want a residual null check left around.  (Causes a slowdown,
3038   // for example, in some objArray manipulations, such as a[i]=a[j].)
3039   if (tk->singleton()) {
3040     const TypeOopPtr* objtp = _gvn.type(obj)->isa_oopptr();
3041     if (objtp != NULL && objtp->klass() != NULL) {
3042       switch (C->static_subtype_check(tk->klass(), objtp->klass())) {
3043       case Compile::SSC_always_true:
3044         // If we know the type check always succeed then we don't use
3045         // the profiling data at this bytecode. Don't lose it, feed it
3046         // to the type system as a speculative type.
3047         return record_profiled_receiver_for_speculation(obj);
3048       case Compile::SSC_always_false:
3049         // It needs a null check because a null will *pass* the cast check.
3050         // A non-null value will always produce an exception.
3051         return null_assert(obj);
3052       }
3053     }
3054   }
3055 
3056   ciProfileData* data = NULL;
3057   bool safe_for_replace = false;
3058   if (failure_control == NULL) {        // use MDO in regular case only
3059     assert(java_bc() == Bytecodes::_aastore ||
3060            java_bc() == Bytecodes::_checkcast,
3061            "interpreter profiles type checks only for these BCs");
3062     data = method()->method_data()->bci_to_data(bci());
3063     safe_for_replace = true;
3064   }
3065 
3066   // Make the merge point
3067   enum { _obj_path = 1, _null_path, PATH_LIMIT };
3068   RegionNode* region = new RegionNode(PATH_LIMIT);
3069   Node*       phi    = new PhiNode(region, toop);
3070   C->set_has_split_ifs(true); // Has chance for split-if optimization
3071 
3072   // Use null-cast information if it is available
3073   bool speculative_not_null = false;
3074   bool never_see_null = ((failure_control == NULL)  // regular case only
3075                          && seems_never_null(obj, data, speculative_not_null));
3076 
3077   // Null check; get casted pointer; set region slot 3
3078   Node* null_ctl = top();
3079   Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null, safe_for_replace, speculative_not_null);
3080 
3081   // If not_null_obj is dead, only null-path is taken
3082   if (stopped()) {              // Doing instance-of on a NULL?
3083     set_control(null_ctl);
3084     return null();
3085   }
3086   region->init_req(_null_path, null_ctl);
3087   phi   ->init_req(_null_path, null());  // Set null path value
3088   if (null_ctl == top()) {
3089     // Do this eagerly, so that pattern matches like is_diamond_phi
3090     // will work even during parsing.
3091     assert(_null_path == PATH_LIMIT-1, "delete last");
3092     region->del_req(_null_path);
3093     phi   ->del_req(_null_path);
3094   }
3095 
3096   Node* cast_obj = NULL;
3097   if (tk->klass_is_exact()) {
3098     // The following optimization tries to statically cast the speculative type of the object
3099     // (for example obtained during profiling) to the type of the superklass and then do a
3100     // dynamic check that the type of the object is what we expect. To work correctly
3101     // for checkcast and aastore the type of superklass should be exact.
3102     const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
3103     // We may not have profiling here or it may not help us. If we have
3104     // a speculative type use it to perform an exact cast.
3105     ciKlass* spec_obj_type = obj_type->speculative_type();
3106     if (spec_obj_type != NULL || data != NULL) {
3107       cast_obj = maybe_cast_profiled_receiver(not_null_obj, tk->klass(), spec_obj_type, safe_for_replace);
3108       if (cast_obj != NULL) {
3109         if (failure_control != NULL) // failure is now impossible
3110           (*failure_control) = top();
3111         // adjust the type of the phi to the exact klass:
3112         phi->raise_bottom_type(_gvn.type(cast_obj)->meet_speculative(TypePtr::NULL_PTR));
3113       }
3114     }
3115   }
3116 
3117   if (cast_obj == NULL) {
3118     // Load the object's klass
3119     Node* obj_klass = load_object_klass(not_null_obj);
3120 
3121     // Generate the subtype check
3122     Node* not_subtype_ctrl = gen_subtype_check( obj_klass, superklass );
3123 
3124     // Plug in success path into the merge
3125     cast_obj = _gvn.transform(new CheckCastPPNode(control(), not_null_obj, toop));
3126     // Failure path ends in uncommon trap (or may be dead - failure impossible)
3127     if (failure_control == NULL) {
3128       if (not_subtype_ctrl != top()) { // If failure is possible
3129         PreserveJVMState pjvms(this);
3130         set_control(not_subtype_ctrl);
3131         builtin_throw(Deoptimization::Reason_class_check, obj_klass);
3132       }
3133     } else {
3134       (*failure_control) = not_subtype_ctrl;
3135     }
3136   }
3137 
3138   region->init_req(_obj_path, control());
3139   phi   ->init_req(_obj_path, cast_obj);
3140 
3141   // A merge of NULL or Casted-NotNull obj
3142   Node* res = _gvn.transform(phi);
3143 
3144   // Note I do NOT always 'replace_in_map(obj,result)' here.
3145   //  if( tk->klass()->can_be_primary_super()  )
3146     // This means that if I successfully store an Object into an array-of-String
3147     // I 'forget' that the Object is really now known to be a String.  I have to
3148     // do this because we don't have true union types for interfaces - if I store
3149     // a Baz into an array-of-Interface and then tell the optimizer it's an
3150     // Interface, I forget that it's also a Baz and cannot do Baz-like field
3151     // references to it.  FIX THIS WHEN UNION TYPES APPEAR!
3152   //  replace_in_map( obj, res );
3153 
3154   // Return final merged results
3155   set_control( _gvn.transform(region) );
3156   record_for_igvn(region);
3157   return res;
3158 }
3159 
3160 //------------------------------next_monitor-----------------------------------
3161 // What number should be given to the next monitor?
3162 int GraphKit::next_monitor() {
3163   int current = jvms()->monitor_depth()* C->sync_stack_slots();
3164   int next = current + C->sync_stack_slots();
3165   // Keep the toplevel high water mark current:
3166   if (C->fixed_slots() < next)  C->set_fixed_slots(next);
3167   return current;
3168 }
3169 
3170 //------------------------------insert_mem_bar---------------------------------
3171 // Memory barrier to avoid floating things around
3172 // The membar serves as a pinch point between both control and all memory slices.
3173 Node* GraphKit::insert_mem_bar(int opcode, Node* precedent) {
3174   MemBarNode* mb = MemBarNode::make(C, opcode, Compile::AliasIdxBot, precedent);
3175   mb->init_req(TypeFunc::Control, control());
3176   mb->init_req(TypeFunc::Memory,  reset_memory());
3177   Node* membar = _gvn.transform(mb);
3178   set_control(_gvn.transform(new ProjNode(membar, TypeFunc::Control)));
3179   set_all_memory_call(membar);
3180   return membar;
3181 }
3182 
3183 //-------------------------insert_mem_bar_volatile----------------------------
3184 // Memory barrier to avoid floating things around
3185 // The membar serves as a pinch point between both control and memory(alias_idx).
3186 // If you want to make a pinch point on all memory slices, do not use this
3187 // function (even with AliasIdxBot); use insert_mem_bar() instead.
3188 Node* GraphKit::insert_mem_bar_volatile(int opcode, int alias_idx, Node* precedent) {
3189   // When Parse::do_put_xxx updates a volatile field, it appends a series
3190   // of MemBarVolatile nodes, one for *each* volatile field alias category.
3191   // The first membar is on the same memory slice as the field store opcode.
3192   // This forces the membar to follow the store.  (Bug 6500685 broke this.)
3193   // All the other membars (for other volatile slices, including AliasIdxBot,
3194   // which stands for all unknown volatile slices) are control-dependent
3195   // on the first membar.  This prevents later volatile loads or stores
3196   // from sliding up past the just-emitted store.
3197 
3198   MemBarNode* mb = MemBarNode::make(C, opcode, alias_idx, precedent);
3199   mb->set_req(TypeFunc::Control,control());
3200   if (alias_idx == Compile::AliasIdxBot) {
3201     mb->set_req(TypeFunc::Memory, merged_memory()->base_memory());
3202   } else {
3203     assert(!(opcode == Op_Initialize && alias_idx != Compile::AliasIdxRaw), "fix caller");
3204     mb->set_req(TypeFunc::Memory, memory(alias_idx));
3205   }
3206   Node* membar = _gvn.transform(mb);
3207   set_control(_gvn.transform(new ProjNode(membar, TypeFunc::Control)));
3208   if (alias_idx == Compile::AliasIdxBot) {
3209     merged_memory()->set_base_memory(_gvn.transform(new ProjNode(membar, TypeFunc::Memory)));
3210   } else {
3211     set_memory(_gvn.transform(new ProjNode(membar, TypeFunc::Memory)),alias_idx);
3212   }
3213   return membar;
3214 }
3215 
3216 void GraphKit::insert_store_load_for_barrier() {
3217   Node* mem = reset_memory();
3218   MemBarNode* mb = MemBarNode::make(C, Op_MemBarVolatile, Compile::AliasIdxBot);
3219   mb->init_req(TypeFunc::Control, control());
3220   mb->init_req(TypeFunc::Memory, mem);
3221   Node* membar = _gvn.transform(mb);
3222   set_control(_gvn.transform(new ProjNode(membar, TypeFunc::Control)));
3223   Node* newmem = _gvn.transform(new ProjNode(membar, TypeFunc::Memory));
3224   set_all_memory(mem);
3225   set_memory(newmem, Compile::AliasIdxRaw);
3226 }
3227 
3228 
3229 //------------------------------shared_lock------------------------------------
3230 // Emit locking code.
3231 FastLockNode* GraphKit::shared_lock(Node* obj) {
3232   // bci is either a monitorenter bc or InvocationEntryBci
3233   // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
3234   assert(SynchronizationEntryBCI == InvocationEntryBci, "");
3235 
3236   if( !GenerateSynchronizationCode )
3237     return NULL;                // Not locking things?
3238   if (stopped())                // Dead monitor?
3239     return NULL;
3240 
3241   assert(dead_locals_are_killed(), "should kill locals before sync. point");
3242 
3243   // Box the stack location
3244   Node* box = _gvn.transform(new BoxLockNode(next_monitor()));
3245   Node* mem = reset_memory();
3246 
3247   FastLockNode * flock = _gvn.transform(new FastLockNode(0, obj, box) )->as_FastLock();
3248   if (UseBiasedLocking && PrintPreciseBiasedLockingStatistics) {
3249     // Create the counters for this fast lock.
3250     flock->create_lock_counter(sync_jvms()); // sync_jvms used to get current bci
3251   }
3252 
3253   // Create the rtm counters for this fast lock if needed.
3254   flock->create_rtm_lock_counter(sync_jvms()); // sync_jvms used to get current bci
3255 
3256   // Add monitor to debug info for the slow path.  If we block inside the
3257   // slow path and de-opt, we need the monitor hanging around
3258   map()->push_monitor( flock );
3259 
3260   const TypeFunc *tf = LockNode::lock_type();
3261   LockNode *lock = new LockNode(C, tf);
3262 
3263   lock->init_req( TypeFunc::Control, control() );
3264   lock->init_req( TypeFunc::Memory , mem );
3265   lock->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
3266   lock->init_req( TypeFunc::FramePtr, frameptr() );
3267   lock->init_req( TypeFunc::ReturnAdr, top() );
3268 
3269   lock->init_req(TypeFunc::Parms + 0, obj);
3270   lock->init_req(TypeFunc::Parms + 1, box);
3271   lock->init_req(TypeFunc::Parms + 2, flock);
3272   add_safepoint_edges(lock);
3273 
3274   lock = _gvn.transform( lock )->as_Lock();
3275 
3276   // lock has no side-effects, sets few values
3277   set_predefined_output_for_runtime_call(lock, mem, TypeRawPtr::BOTTOM);
3278 
3279   insert_mem_bar(Op_MemBarAcquireLock);
3280 
3281   // Add this to the worklist so that the lock can be eliminated
3282   record_for_igvn(lock);
3283 
3284 #ifndef PRODUCT
3285   if (PrintLockStatistics) {
3286     // Update the counter for this lock.  Don't bother using an atomic
3287     // operation since we don't require absolute accuracy.
3288     lock->create_lock_counter(map()->jvms());
3289     increment_counter(lock->counter()->addr());
3290   }
3291 #endif
3292 
3293   return flock;
3294 }
3295 
3296 
3297 //------------------------------shared_unlock----------------------------------
3298 // Emit unlocking code.
3299 void GraphKit::shared_unlock(Node* box, Node* obj) {
3300   // bci is either a monitorenter bc or InvocationEntryBci
3301   // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
3302   assert(SynchronizationEntryBCI == InvocationEntryBci, "");
3303 
3304   if( !GenerateSynchronizationCode )
3305     return;
3306   if (stopped()) {               // Dead monitor?
3307     map()->pop_monitor();        // Kill monitor from debug info
3308     return;
3309   }
3310 
3311   // Memory barrier to avoid floating things down past the locked region
3312   insert_mem_bar(Op_MemBarReleaseLock);
3313 
3314   const TypeFunc *tf = OptoRuntime::complete_monitor_exit_Type();
3315   UnlockNode *unlock = new UnlockNode(C, tf);
3316 #ifdef ASSERT
3317   unlock->set_dbg_jvms(sync_jvms());
3318 #endif
3319   uint raw_idx = Compile::AliasIdxRaw;
3320   unlock->init_req( TypeFunc::Control, control() );
3321   unlock->init_req( TypeFunc::Memory , memory(raw_idx) );
3322   unlock->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
3323   unlock->init_req( TypeFunc::FramePtr, frameptr() );
3324   unlock->init_req( TypeFunc::ReturnAdr, top() );
3325 
3326   unlock->init_req(TypeFunc::Parms + 0, obj);
3327   unlock->init_req(TypeFunc::Parms + 1, box);
3328   unlock = _gvn.transform(unlock)->as_Unlock();
3329 
3330   Node* mem = reset_memory();
3331 
3332   // unlock has no side-effects, sets few values
3333   set_predefined_output_for_runtime_call(unlock, mem, TypeRawPtr::BOTTOM);
3334 
3335   // Kill monitor from debug info
3336   map()->pop_monitor( );
3337 }
3338 
3339 //-------------------------------get_layout_helper-----------------------------
3340 // If the given klass is a constant or known to be an array,
3341 // fetch the constant layout helper value into constant_value
3342 // and return (Node*)NULL.  Otherwise, load the non-constant
3343 // layout helper value, and return the node which represents it.
3344 // This two-faced routine is useful because allocation sites
3345 // almost always feature constant types.
3346 Node* GraphKit::get_layout_helper(Node* klass_node, jint& constant_value) {
3347   const TypeKlassPtr* inst_klass = _gvn.type(klass_node)->isa_klassptr();
3348   if (!StressReflectiveCode && inst_klass != NULL) {
3349     ciKlass* klass = inst_klass->klass();
3350     bool    xklass = inst_klass->klass_is_exact();
3351     if (xklass || klass->is_array_klass()) {
3352       jint lhelper = klass->layout_helper();
3353       if (lhelper != Klass::_lh_neutral_value) {
3354         constant_value = lhelper;
3355         return (Node*) NULL;
3356       }
3357     }
3358   }
3359   constant_value = Klass::_lh_neutral_value;  // put in a known value
3360   Node* lhp = basic_plus_adr(klass_node, klass_node, in_bytes(Klass::layout_helper_offset()));
3361   return make_load(NULL, lhp, TypeInt::INT, T_INT, MemNode::unordered);
3362 }
3363 
3364 // We just put in an allocate/initialize with a big raw-memory effect.
3365 // Hook selected additional alias categories on the initialization.
3366 static void hook_memory_on_init(GraphKit& kit, int alias_idx,
3367                                 MergeMemNode* init_in_merge,
3368                                 Node* init_out_raw) {
3369   DEBUG_ONLY(Node* init_in_raw = init_in_merge->base_memory());
3370   assert(init_in_merge->memory_at(alias_idx) == init_in_raw, "");
3371 
3372   Node* prevmem = kit.memory(alias_idx);
3373   init_in_merge->set_memory_at(alias_idx, prevmem);
3374   kit.set_memory(init_out_raw, alias_idx);
3375 }
3376 
3377 //---------------------------set_output_for_allocation-------------------------
3378 Node* GraphKit::set_output_for_allocation(AllocateNode* alloc,
3379                                           const TypeOopPtr* oop_type,
3380                                           bool deoptimize_on_exception) {
3381   int rawidx = Compile::AliasIdxRaw;
3382   alloc->set_req( TypeFunc::FramePtr, frameptr() );
3383   add_safepoint_edges(alloc);
3384   Node* allocx = _gvn.transform(alloc);
3385   set_control( _gvn.transform(new ProjNode(allocx, TypeFunc::Control) ) );
3386   // create memory projection for i_o
3387   set_memory ( _gvn.transform( new ProjNode(allocx, TypeFunc::Memory, true) ), rawidx );
3388   make_slow_call_ex(allocx, env()->Throwable_klass(), true, deoptimize_on_exception);
3389 
3390   // create a memory projection as for the normal control path
3391   Node* malloc = _gvn.transform(new ProjNode(allocx, TypeFunc::Memory));
3392   set_memory(malloc, rawidx);
3393 
3394   // a normal slow-call doesn't change i_o, but an allocation does
3395   // we create a separate i_o projection for the normal control path
3396   set_i_o(_gvn.transform( new ProjNode(allocx, TypeFunc::I_O, false) ) );
3397   Node* rawoop = _gvn.transform( new ProjNode(allocx, TypeFunc::Parms) );
3398 
3399   // put in an initialization barrier
3400   InitializeNode* init = insert_mem_bar_volatile(Op_Initialize, rawidx,
3401                                                  rawoop)->as_Initialize();
3402   assert(alloc->initialization() == init,  "2-way macro link must work");
3403   assert(init ->allocation()     == alloc, "2-way macro link must work");
3404   {
3405     // Extract memory strands which may participate in the new object's
3406     // initialization, and source them from the new InitializeNode.
3407     // This will allow us to observe initializations when they occur,
3408     // and link them properly (as a group) to the InitializeNode.
3409     assert(init->in(InitializeNode::Memory) == malloc, "");
3410     MergeMemNode* minit_in = MergeMemNode::make(malloc);
3411     init->set_req(InitializeNode::Memory, minit_in);
3412     record_for_igvn(minit_in); // fold it up later, if possible
3413     Node* minit_out = memory(rawidx);
3414     assert(minit_out->is_Proj() && minit_out->in(0) == init, "");
3415     if (oop_type->isa_aryptr()) {
3416       const TypePtr* telemref = oop_type->add_offset(Type::OffsetBot);
3417       int            elemidx  = C->get_alias_index(telemref);
3418       hook_memory_on_init(*this, elemidx, minit_in, minit_out);
3419     } else if (oop_type->isa_instptr() || oop_type->isa_valuetypeptr()) {
3420       ciInstanceKlass* ik = oop_type->klass()->as_instance_klass();
3421       for (int i = 0, len = ik->nof_nonstatic_fields(); i < len; i++) {
3422         ciField* field = ik->nonstatic_field_at(i);
3423         if (field->offset() >= TrackedInitializationLimit * HeapWordSize)
3424           continue;  // do not bother to track really large numbers of fields
3425         // Find (or create) the alias category for this field:
3426         int fieldidx = C->alias_type(field)->index();
3427         hook_memory_on_init(*this, fieldidx, minit_in, minit_out);
3428       }
3429     }
3430   }
3431 
3432   // Cast raw oop to the real thing...
3433   Node* javaoop = new CheckCastPPNode(control(), rawoop, oop_type);
3434   javaoop = _gvn.transform(javaoop);
3435   C->set_recent_alloc(control(), javaoop);
3436   assert(just_allocated_object(control()) == javaoop, "just allocated");
3437 
3438 #ifdef ASSERT
3439   { // Verify that the AllocateNode::Ideal_allocation recognizers work:
3440     assert(AllocateNode::Ideal_allocation(rawoop, &_gvn) == alloc,
3441            "Ideal_allocation works");
3442     assert(AllocateNode::Ideal_allocation(javaoop, &_gvn) == alloc,
3443            "Ideal_allocation works");
3444     if (alloc->is_AllocateArray()) {
3445       assert(AllocateArrayNode::Ideal_array_allocation(rawoop, &_gvn) == alloc->as_AllocateArray(),
3446              "Ideal_allocation works");
3447       assert(AllocateArrayNode::Ideal_array_allocation(javaoop, &_gvn) == alloc->as_AllocateArray(),
3448              "Ideal_allocation works");
3449     } else {
3450       assert(alloc->in(AllocateNode::ALength)->is_top(), "no length, please");
3451     }
3452   }
3453 #endif //ASSERT
3454 
3455   return javaoop;
3456 }
3457 
3458 //---------------------------new_instance--------------------------------------
3459 // This routine takes a klass_node which may be constant (for a static type)
3460 // or may be non-constant (for reflective code).  It will work equally well
3461 // for either, and the graph will fold nicely if the optimizer later reduces
3462 // the type to a constant.
3463 // The optional arguments are for specialized use by intrinsics:
3464 //  - If 'extra_slow_test' if not null is an extra condition for the slow-path.
3465 //  - If 'return_size_val', report the the total object size to the caller.
3466 //  - deoptimize_on_exception controls how Java exceptions are handled (rethrow vs deoptimize)
3467 Node* GraphKit::new_instance(Node* klass_node,
3468                              Node* extra_slow_test,
3469                              Node* *return_size_val,
3470                              bool deoptimize_on_exception) {
3471   // Compute size in doublewords
3472   // The size is always an integral number of doublewords, represented
3473   // as a positive bytewise size stored in the klass's layout_helper.
3474   // The layout_helper also encodes (in a low bit) the need for a slow path.
3475   jint  layout_con = Klass::_lh_neutral_value;
3476   Node* layout_val = get_layout_helper(klass_node, layout_con);
3477   int   layout_is_con = (layout_val == NULL);
3478 
3479   if (extra_slow_test == NULL)  extra_slow_test = intcon(0);
3480   // Generate the initial go-slow test.  It's either ALWAYS (return a
3481   // Node for 1) or NEVER (return a NULL) or perhaps (in the reflective
3482   // case) a computed value derived from the layout_helper.
3483   Node* initial_slow_test = NULL;
3484   if (layout_is_con) {
3485     assert(!StressReflectiveCode, "stress mode does not use these paths");
3486     bool must_go_slow = Klass::layout_helper_needs_slow_path(layout_con);
3487     initial_slow_test = must_go_slow ? intcon(1) : extra_slow_test;
3488   } else {   // reflective case
3489     // This reflective path is used by Unsafe.allocateInstance.
3490     // (It may be stress-tested by specifying StressReflectiveCode.)
3491     // Basically, we want to get into the VM is there's an illegal argument.
3492     Node* bit = intcon(Klass::_lh_instance_slow_path_bit);
3493     initial_slow_test = _gvn.transform( new AndINode(layout_val, bit) );
3494     if (extra_slow_test != intcon(0)) {
3495       initial_slow_test = _gvn.transform( new OrINode(initial_slow_test, extra_slow_test) );
3496     }
3497     // (Macro-expander will further convert this to a Bool, if necessary.)
3498   }
3499 
3500   // Find the size in bytes.  This is easy; it's the layout_helper.
3501   // The size value must be valid even if the slow path is taken.
3502   Node* size = NULL;
3503   if (layout_is_con) {
3504     size = MakeConX(Klass::layout_helper_size_in_bytes(layout_con));
3505   } else {   // reflective case
3506     // This reflective path is used by clone and Unsafe.allocateInstance.
3507     size = ConvI2X(layout_val);
3508 
3509     // Clear the low bits to extract layout_helper_size_in_bytes:
3510     assert((int)Klass::_lh_instance_slow_path_bit < BytesPerLong, "clear bit");
3511     Node* mask = MakeConX(~ (intptr_t)right_n_bits(LogBytesPerLong));
3512     size = _gvn.transform( new AndXNode(size, mask) );
3513   }
3514   if (return_size_val != NULL) {
3515     (*return_size_val) = size;
3516   }
3517 
3518   // This is a precise notnull oop of the klass.
3519   // (Actually, it need not be precise if this is a reflective allocation.)
3520   // It's what we cast the result to.
3521   const TypeKlassPtr* tklass = _gvn.type(klass_node)->isa_klassptr();
3522   if (!tklass)  tklass = TypeKlassPtr::OBJECT;
3523   const TypeOopPtr* oop_type = tklass->as_instance_type();
3524 
3525   // Now generate allocation code
3526 
3527   // The entire memory state is needed for slow path of the allocation
3528   // since GC and deoptimization can happen.
3529   Node *mem = reset_memory();
3530   set_all_memory(mem); // Create new memory state
3531 
3532   AllocateNode* alloc = new AllocateNode(C, AllocateNode::alloc_type(Type::TOP),
3533                                          control(), mem, i_o(),
3534                                          size, klass_node,
3535                                          initial_slow_test);
3536 
3537   return set_output_for_allocation(alloc, oop_type, deoptimize_on_exception);
3538 }
3539 
3540 //-------------------------------new_array-------------------------------------
3541 // helper for newarray, anewarray and vnewarray
3542 // The 'length' parameter is (obviously) the length of the array.
3543 // See comments on new_instance for the meaning of the other arguments.
3544 Node* GraphKit::new_array(Node* klass_node,     // array klass (maybe variable)
3545                           Node* length,         // number of array elements
3546                           int   nargs,          // number of arguments to push back for uncommon trap
3547                           Node* *return_size_val,
3548                           bool deoptimize_on_exception) {
3549   jint  layout_con = Klass::_lh_neutral_value;
3550   Node* layout_val = get_layout_helper(klass_node, layout_con);
3551   int   layout_is_con = (layout_val == NULL);
3552 
3553   if (!layout_is_con && !StressReflectiveCode &&
3554       !too_many_traps(Deoptimization::Reason_class_check)) {
3555     // This is a reflective array creation site.
3556     // Optimistically assume that it is a subtype of Object[],
3557     // so that we can fold up all the address arithmetic.
3558     layout_con = Klass::array_layout_helper(T_OBJECT);
3559     Node* cmp_lh = _gvn.transform( new CmpINode(layout_val, intcon(layout_con)) );
3560     Node* bol_lh = _gvn.transform( new BoolNode(cmp_lh, BoolTest::eq) );
3561     { BuildCutout unless(this, bol_lh, PROB_MAX);
3562       inc_sp(nargs);
3563       uncommon_trap(Deoptimization::Reason_class_check,
3564                     Deoptimization::Action_maybe_recompile);
3565     }
3566     layout_val = NULL;
3567     layout_is_con = true;
3568   }
3569 
3570   // Generate the initial go-slow test.  Make sure we do not overflow
3571   // if length is huge (near 2Gig) or negative!  We do not need
3572   // exact double-words here, just a close approximation of needed
3573   // double-words.  We can't add any offset or rounding bits, lest we
3574   // take a size -1 of bytes and make it positive.  Use an unsigned
3575   // compare, so negative sizes look hugely positive.
3576   int fast_size_limit = FastAllocateSizeLimit;
3577   if (layout_is_con) {
3578     assert(!StressReflectiveCode, "stress mode does not use these paths");
3579     // Increase the size limit if we have exact knowledge of array type.
3580     int log2_esize = Klass::layout_helper_log2_element_size(layout_con);
3581     fast_size_limit <<= (LogBytesPerLong - log2_esize);
3582   }
3583 
3584   Node* initial_slow_cmp  = _gvn.transform( new CmpUNode( length, intcon( fast_size_limit ) ) );
3585   Node* initial_slow_test = _gvn.transform( new BoolNode( initial_slow_cmp, BoolTest::gt ) );
3586 
3587   // --- Size Computation ---
3588   // array_size = round_to_heap(array_header + (length << elem_shift));
3589   // where round_to_heap(x) == round_to(x, MinObjAlignmentInBytes)
3590   // and round_to(x, y) == ((x + y-1) & ~(y-1))
3591   // The rounding mask is strength-reduced, if possible.
3592   int round_mask = MinObjAlignmentInBytes - 1;
3593   Node* header_size = NULL;
3594   int   header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
3595   // (T_BYTE has the weakest alignment and size restrictions...)
3596   if (layout_is_con) {
3597     int       hsize  = Klass::layout_helper_header_size(layout_con);
3598     int       eshift = Klass::layout_helper_log2_element_size(layout_con);
3599     BasicType etype  = Klass::layout_helper_element_type(layout_con);
3600     bool is_value_array = Klass::layout_helper_is_valueArray(layout_con);
3601     if ((round_mask & ~right_n_bits(eshift)) == 0)
3602       round_mask = 0;  // strength-reduce it if it goes away completely
3603     assert(is_value_array || (hsize & right_n_bits(eshift)) == 0, "hsize is pre-rounded");
3604     assert(header_size_min <= hsize, "generic minimum is smallest");
3605     header_size_min = hsize;
3606     header_size = intcon(hsize + round_mask);
3607   } else {
3608     Node* hss   = intcon(Klass::_lh_header_size_shift);
3609     Node* hsm   = intcon(Klass::_lh_header_size_mask);
3610     Node* hsize = _gvn.transform( new URShiftINode(layout_val, hss) );
3611     hsize       = _gvn.transform( new AndINode(hsize, hsm) );
3612     Node* mask  = intcon(round_mask);
3613     header_size = _gvn.transform( new AddINode(hsize, mask) );
3614   }
3615 
3616   Node* elem_shift = NULL;
3617   if (layout_is_con) {
3618     int eshift = Klass::layout_helper_log2_element_size(layout_con);
3619     if (eshift != 0)
3620       elem_shift = intcon(eshift);
3621   } else {
3622     // There is no need to mask or shift this value.
3623     // The semantics of LShiftINode include an implicit mask to 0x1F.
3624     assert(Klass::_lh_log2_element_size_shift == 0, "use shift in place");
3625     elem_shift = layout_val;
3626   }
3627 
3628   // Transition to native address size for all offset calculations:
3629   Node* lengthx = ConvI2X(length);
3630   Node* headerx = ConvI2X(header_size);
3631 #ifdef _LP64
3632   { const TypeInt* tilen = _gvn.find_int_type(length);
3633     if (tilen != NULL && tilen->_lo < 0) {
3634       // Add a manual constraint to a positive range.  Cf. array_element_address.
3635       jint size_max = fast_size_limit;
3636       if (size_max > tilen->_hi)  size_max = tilen->_hi;
3637       const TypeInt* tlcon = TypeInt::make(0, size_max, Type::WidenMin);
3638 
3639       // Only do a narrow I2L conversion if the range check passed.
3640       IfNode* iff = new IfNode(control(), initial_slow_test, PROB_MIN, COUNT_UNKNOWN);
3641       _gvn.transform(iff);
3642       RegionNode* region = new RegionNode(3);
3643       _gvn.set_type(region, Type::CONTROL);
3644       lengthx = new PhiNode(region, TypeLong::LONG);
3645       _gvn.set_type(lengthx, TypeLong::LONG);
3646 
3647       // Range check passed. Use ConvI2L node with narrow type.
3648       Node* passed = IfFalse(iff);
3649       region->init_req(1, passed);
3650       // Make I2L conversion control dependent to prevent it from
3651       // floating above the range check during loop optimizations.
3652       lengthx->init_req(1, C->constrained_convI2L(&_gvn, length, tlcon, passed));
3653 
3654       // Range check failed. Use ConvI2L with wide type because length may be invalid.
3655       region->init_req(2, IfTrue(iff));
3656       lengthx->init_req(2, ConvI2X(length));
3657 
3658       set_control(region);
3659       record_for_igvn(region);
3660       record_for_igvn(lengthx);
3661     }
3662   }
3663 #endif
3664 
3665   // Combine header size (plus rounding) and body size.  Then round down.
3666   // This computation cannot overflow, because it is used only in two
3667   // places, one where the length is sharply limited, and the other
3668   // after a successful allocation.
3669   Node* abody = lengthx;
3670   if (elem_shift != NULL)
3671     abody     = _gvn.transform( new LShiftXNode(lengthx, elem_shift) );
3672   Node* size  = _gvn.transform( new AddXNode(headerx, abody) );
3673   if (round_mask != 0) {
3674     Node* mask = MakeConX(~round_mask);
3675     size       = _gvn.transform( new AndXNode(size, mask) );
3676   }
3677   // else if round_mask == 0, the size computation is self-rounding
3678 
3679   if (return_size_val != NULL) {
3680     // This is the size
3681     (*return_size_val) = size;
3682   }
3683 
3684   // Now generate allocation code
3685 
3686   // The entire memory state is needed for slow path of the allocation
3687   // since GC and deoptimization can happen.
3688   Node *mem = reset_memory();
3689   set_all_memory(mem); // Create new memory state
3690 
3691   if (initial_slow_test->is_Bool()) {
3692     // Hide it behind a CMoveI, or else PhaseIdealLoop::split_up will get sick.
3693     initial_slow_test = initial_slow_test->as_Bool()->as_int_value(&_gvn);
3694   }
3695 
3696   // Create the AllocateArrayNode and its result projections
3697   AllocateArrayNode* alloc
3698     = new AllocateArrayNode(C, AllocateArrayNode::alloc_type(TypeInt::INT),
3699                             control(), mem, i_o(),
3700                             size, klass_node,
3701                             initial_slow_test,
3702                             length);
3703 
3704   // Cast to correct type.  Note that the klass_node may be constant or not,
3705   // and in the latter case the actual array type will be inexact also.
3706   // (This happens via a non-constant argument to inline_native_newArray.)
3707   // In any case, the value of klass_node provides the desired array type.
3708   const TypeInt* length_type = _gvn.find_int_type(length);
3709   const TypeOopPtr* ary_type = _gvn.type(klass_node)->is_klassptr()->as_instance_type();
3710   if (ary_type->isa_aryptr() && length_type != NULL) {
3711     // Try to get a better type than POS for the size
3712     ary_type = ary_type->is_aryptr()->cast_to_size(length_type);
3713   }
3714 
3715   Node* javaoop = set_output_for_allocation(alloc, ary_type, deoptimize_on_exception);
3716 
3717   // Cast length on remaining path to be as narrow as possible
3718   if (map()->find_edge(length) >= 0) {
3719     Node* ccast = alloc->make_ideal_length(ary_type, &_gvn);
3720     if (ccast != length) {
3721       _gvn.set_type_bottom(ccast);
3722       record_for_igvn(ccast);
3723       replace_in_map(length, ccast);
3724     }
3725   }
3726 
3727   const TypeAryPtr* ary_ptr = ary_type->isa_aryptr();
3728   ciKlass* elem_klass = ary_ptr != NULL ? ary_ptr->klass()->as_array_klass()->element_klass() : NULL;
3729   if (elem_klass != NULL && elem_klass->is_valuetype()) {
3730     ciValueKlass* vk = elem_klass->as_value_klass();
3731     if (!vk->flatten_array()) {
3732       // Non-flattened value type arrays need to be initialized with default value type oops
3733       initialize_value_type_array(javaoop, length, elem_klass->as_value_klass(), nargs);
3734       InitializeNode* init = alloc->initialization();
3735       init->set_complete_with_arraycopy();
3736     }
3737   }
3738 
3739   return javaoop;
3740 }
3741 
3742 void GraphKit::initialize_value_type_array(Node* array, Node* length, ciValueKlass* vk, int nargs) {
3743   // Check for zero length
3744   Node* null_ctl = top();
3745   null_check_common(length, T_INT, false, &null_ctl, false);
3746   if (stopped()) {
3747     set_control(null_ctl); // Always zero
3748     return;
3749   }
3750 
3751   // Prepare for merging control and IO
3752   RegionNode* res_ctl = new RegionNode(3);
3753   res_ctl->init_req(1, null_ctl);
3754   gvn().set_type(res_ctl, Type::CONTROL);
3755   record_for_igvn(res_ctl);
3756   Node* res_io = PhiNode::make(res_ctl, i_o(), Type::ABIO);
3757   gvn().set_type(res_io, Type::ABIO);
3758   record_for_igvn(res_io);
3759 
3760   // TODO comment
3761   SafePointNode* loop_map = NULL;
3762   {
3763     PreserveJVMState pjvms(this);
3764     // Create default value type and store it to memory
3765     Node* oop = ValueTypeNode::make_default(gvn(), vk);
3766     oop = oop->as_ValueType()->store_to_memory(this);
3767 
3768     length = SubI(length, intcon(1));
3769     add_predicate(nargs);
3770     RegionNode* loop = new RegionNode(3);
3771     loop->init_req(1, control());
3772     gvn().set_type(loop, Type::CONTROL);
3773     record_for_igvn(loop);
3774 
3775     Node* index = new PhiNode(loop, TypeInt::INT);
3776     index->init_req(1, intcon(0));
3777     gvn().set_type(index, TypeInt::INT);
3778     record_for_igvn(index);
3779 
3780     // TODO explain why we need to capture all memory
3781     PhiNode* mem = new PhiNode(loop, Type::MEMORY, TypePtr::BOTTOM);
3782     mem->init_req(1, reset_memory());
3783     gvn().set_type(mem, Type::MEMORY);
3784     record_for_igvn(mem);
3785     set_control(loop);
3786     set_all_memory(mem);
3787     // Initialize array element
3788     Node* adr = array_element_address(array, index, T_OBJECT);
3789     const TypeOopPtr* elemtype = TypeValueTypePtr::make(TypePtr::NotNull, vk);
3790     Node* store = store_oop_to_array(control(), array, adr, TypeAryPtr::OOPS, oop, elemtype, T_OBJECT, MemNode::release);
3791 
3792     IfNode* iff = create_and_map_if(control(), Bool(CmpI(index, length), BoolTest::lt), PROB_FAIR, COUNT_UNKNOWN);
3793     loop->init_req(2, IfTrue(iff));
3794     mem->init_req(2, merged_memory());
3795     index->init_req(2, AddI(index, intcon(1)));
3796 
3797     res_ctl->init_req(2, IfFalse(iff));
3798     res_io->set_req(2, i_o());
3799     loop_map = stop();
3800   }
3801   // Set merged control, IO and memory
3802   set_control(res_ctl);
3803   set_i_o(res_io);
3804   merge_memory(loop_map->merged_memory(), res_ctl, 2);
3805 
3806   // Transform new memory Phis.
3807   for (MergeMemStream mms(merged_memory()); mms.next_non_empty();) {
3808     Node* phi = mms.memory();
3809     if (phi->is_Phi() && phi->in(0) == res_ctl) {
3810       mms.set_memory(gvn().transform(phi));
3811     }
3812   }
3813 }
3814 
3815 // The following "Ideal_foo" functions are placed here because they recognize
3816 // the graph shapes created by the functions immediately above.
3817 
3818 //---------------------------Ideal_allocation----------------------------------
3819 // Given an oop pointer or raw pointer, see if it feeds from an AllocateNode.
3820 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase) {
3821   if (ptr == NULL) {     // reduce dumb test in callers
3822     return NULL;
3823   }
3824   if (ptr->is_CheckCastPP()) { // strip only one raw-to-oop cast
3825     ptr = ptr->in(1);
3826     if (ptr == NULL) return NULL;
3827   }
3828   // Return NULL for allocations with several casts:
3829   //   j.l.reflect.Array.newInstance(jobject, jint)
3830   //   Object.clone()
3831   // to keep more precise type from last cast.
3832   if (ptr->is_Proj()) {
3833     Node* allo = ptr->in(0);
3834     if (allo != NULL && allo->is_Allocate()) {
3835       return allo->as_Allocate();
3836     }
3837   }
3838   // Report failure to match.
3839   return NULL;
3840 }
3841 
3842 // Fancy version which also strips off an offset (and reports it to caller).
3843 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase,
3844                                              intptr_t& offset) {
3845   Node* base = AddPNode::Ideal_base_and_offset(ptr, phase, offset);
3846   if (base == NULL)  return NULL;
3847   return Ideal_allocation(base, phase);
3848 }
3849 
3850 // Trace Initialize <- Proj[Parm] <- Allocate
3851 AllocateNode* InitializeNode::allocation() {
3852   Node* rawoop = in(InitializeNode::RawAddress);
3853   if (rawoop->is_Proj()) {
3854     Node* alloc = rawoop->in(0);
3855     if (alloc->is_Allocate()) {
3856       return alloc->as_Allocate();
3857     }
3858   }
3859   return NULL;
3860 }
3861 
3862 // Trace Allocate -> Proj[Parm] -> Initialize
3863 InitializeNode* AllocateNode::initialization() {
3864   ProjNode* rawoop = proj_out(AllocateNode::RawAddress);
3865   if (rawoop == NULL)  return NULL;
3866   for (DUIterator_Fast imax, i = rawoop->fast_outs(imax); i < imax; i++) {
3867     Node* init = rawoop->fast_out(i);
3868     if (init->is_Initialize()) {
3869       assert(init->as_Initialize()->allocation() == this, "2-way link");
3870       return init->as_Initialize();
3871     }
3872   }
3873   return NULL;
3874 }
3875 
3876 //----------------------------- loop predicates ---------------------------
3877 
3878 //------------------------------add_predicate_impl----------------------------
3879 void GraphKit::add_predicate_impl(Deoptimization::DeoptReason reason, int nargs) {
3880   // Too many traps seen?
3881   if (too_many_traps(reason)) {
3882 #ifdef ASSERT
3883     if (TraceLoopPredicate) {
3884       int tc = C->trap_count(reason);
3885       tty->print("too many traps=%s tcount=%d in ",
3886                     Deoptimization::trap_reason_name(reason), tc);
3887       method()->print(); // which method has too many predicate traps
3888       tty->cr();
3889     }
3890 #endif
3891     // We cannot afford to take more traps here,
3892     // do not generate predicate.
3893     return;
3894   }
3895 
3896   Node *cont    = _gvn.intcon(1);
3897   Node* opq     = _gvn.transform(new Opaque1Node(C, cont));
3898   Node *bol     = _gvn.transform(new Conv2BNode(opq));
3899   IfNode* iff   = create_and_map_if(control(), bol, PROB_MAX, COUNT_UNKNOWN);
3900   Node* iffalse = _gvn.transform(new IfFalseNode(iff));
3901   C->add_predicate_opaq(opq);
3902   {
3903     PreserveJVMState pjvms(this);
3904     set_control(iffalse);
3905     inc_sp(nargs);
3906     uncommon_trap(reason, Deoptimization::Action_maybe_recompile);
3907   }
3908   Node* iftrue = _gvn.transform(new IfTrueNode(iff));
3909   set_control(iftrue);
3910 }
3911 
3912 //------------------------------add_predicate---------------------------------
3913 void GraphKit::add_predicate(int nargs) {
3914   if (UseLoopPredicate) {
3915     add_predicate_impl(Deoptimization::Reason_predicate, nargs);
3916   }
3917   // loop's limit check predicate should be near the loop.
3918   if (LoopLimitCheck) {
3919     add_predicate_impl(Deoptimization::Reason_loop_limit_check, nargs);
3920   }
3921 }
3922 
3923 //----------------------------- store barriers ----------------------------
3924 #define __ ideal.
3925 
3926 void GraphKit::sync_kit(IdealKit& ideal) {
3927   set_all_memory(__ merged_memory());
3928   set_i_o(__ i_o());
3929   set_control(__ ctrl());
3930 }
3931 
3932 void GraphKit::final_sync(IdealKit& ideal) {
3933   // Final sync IdealKit and graphKit.
3934   sync_kit(ideal);
3935 }
3936 
3937 Node* GraphKit::byte_map_base_node() {
3938   // Get base of card map
3939   CardTableModRefBS* ct =
3940     barrier_set_cast<CardTableModRefBS>(Universe::heap()->barrier_set());
3941   assert(sizeof(*ct->byte_map_base) == sizeof(jbyte), "adjust users of this code");
3942   if (ct->byte_map_base != NULL) {
3943     return makecon(TypeRawPtr::make((address)ct->byte_map_base));
3944   } else {
3945     return null();
3946   }
3947 }
3948 
3949 // vanilla/CMS post barrier
3950 // Insert a write-barrier store.  This is to let generational GC work; we have
3951 // to flag all oop-stores before the next GC point.
3952 void GraphKit::write_barrier_post(Node* oop_store,
3953                                   Node* obj,
3954                                   Node* adr,
3955                                   uint  adr_idx,
3956                                   Node* val,
3957                                   bool use_precise) {
3958   // No store check needed if we're storing a NULL or an old object
3959   // (latter case is probably a string constant). The concurrent
3960   // mark sweep garbage collector, however, needs to have all nonNull
3961   // oop updates flagged via card-marks.
3962   if (val != NULL && val->is_Con()) {
3963     // must be either an oop or NULL
3964     const Type* t = val->bottom_type();
3965     if (t == TypePtr::NULL_PTR || t == Type::TOP)
3966       // stores of null never (?) need barriers
3967       return;
3968   }
3969 
3970   if (use_ReduceInitialCardMarks()
3971       && obj == just_allocated_object(control())) {
3972     // We can skip marks on a freshly-allocated object in Eden.
3973     // Keep this code in sync with new_store_pre_barrier() in runtime.cpp.
3974     // That routine informs GC to take appropriate compensating steps,
3975     // upon a slow-path allocation, so as to make this card-mark
3976     // elision safe.
3977     return;
3978   }
3979 
3980   if (!use_precise) {
3981     // All card marks for a (non-array) instance are in one place:
3982     adr = obj;
3983   }
3984   // (Else it's an array (or unknown), and we want more precise card marks.)
3985   assert(adr != NULL, "");
3986 
3987   IdealKit ideal(this, true);
3988 
3989   // Convert the pointer to an int prior to doing math on it
3990   Node* cast = __ CastPX(__ ctrl(), adr);
3991 
3992   // Divide by card size
3993   assert(Universe::heap()->barrier_set()->is_a(BarrierSet::CardTableModRef),
3994          "Only one we handle so far.");
3995   Node* card_offset = __ URShiftX( cast, __ ConI(CardTableModRefBS::card_shift) );
3996 
3997   // Combine card table base and card offset
3998   Node* card_adr = __ AddP(__ top(), byte_map_base_node(), card_offset );
3999 
4000   // Get the alias_index for raw card-mark memory
4001   int adr_type = Compile::AliasIdxRaw;
4002   Node*   zero = __ ConI(0); // Dirty card value
4003   BasicType bt = T_BYTE;
4004 
4005   if (UseConcMarkSweepGC && UseCondCardMark) {
4006     insert_store_load_for_barrier();
4007     __ sync_kit(this);
4008   }
4009 
4010   if (UseCondCardMark) {
4011     // The classic GC reference write barrier is typically implemented
4012     // as a store into the global card mark table.  Unfortunately
4013     // unconditional stores can result in false sharing and excessive
4014     // coherence traffic as well as false transactional aborts.
4015     // UseCondCardMark enables MP "polite" conditional card mark
4016     // stores.  In theory we could relax the load from ctrl() to
4017     // no_ctrl, but that doesn't buy much latitude.
4018     Node* card_val = __ load( __ ctrl(), card_adr, TypeInt::BYTE, bt, adr_type);
4019     __ if_then(card_val, BoolTest::ne, zero);
4020   }
4021 
4022   // Smash zero into card
4023   if( !UseConcMarkSweepGC ) {
4024     __ store(__ ctrl(), card_adr, zero, bt, adr_type, MemNode::unordered);
4025   } else {
4026     // Specialized path for CM store barrier
4027     __ storeCM(__ ctrl(), card_adr, zero, oop_store, adr_idx, bt, adr_type);
4028   }
4029 
4030   if (UseCondCardMark) {
4031     __ end_if();
4032   }
4033 
4034   // Final sync IdealKit and GraphKit.
4035   final_sync(ideal);
4036 }
4037 /*
4038  * Determine if the G1 pre-barrier can be removed. The pre-barrier is
4039  * required by SATB to make sure all objects live at the start of the
4040  * marking are kept alive, all reference updates need to any previous
4041  * reference stored before writing.
4042  *
4043  * If the previous value is NULL there is no need to save the old value.
4044  * References that are NULL are filtered during runtime by the barrier
4045  * code to avoid unnecessary queuing.
4046  *
4047  * However in the case of newly allocated objects it might be possible to
4048  * prove that the reference about to be overwritten is NULL during compile
4049  * time and avoid adding the barrier code completely.
4050  *
4051  * The compiler needs to determine that the object in which a field is about
4052  * to be written is newly allocated, and that no prior store to the same field
4053  * has happened since the allocation.
4054  *
4055  * Returns true if the pre-barrier can be removed
4056  */
4057 bool GraphKit::g1_can_remove_pre_barrier(PhaseTransform* phase, Node* adr,
4058                                          BasicType bt, uint adr_idx) {
4059   intptr_t offset = 0;
4060   Node* base = AddPNode::Ideal_base_and_offset(adr, phase, offset);
4061   AllocateNode* alloc = AllocateNode::Ideal_allocation(base, phase);
4062 
4063   if (offset == Type::OffsetBot) {
4064     return false; // cannot unalias unless there are precise offsets
4065   }
4066 
4067   if (alloc == NULL) {
4068     return false; // No allocation found
4069   }
4070 
4071   intptr_t size_in_bytes = type2aelembytes(bt);
4072 
4073   Node* mem = memory(adr_idx); // start searching here...
4074 
4075   for (int cnt = 0; cnt < 50; cnt++) {
4076 
4077     if (mem->is_Store()) {
4078 
4079       Node* st_adr = mem->in(MemNode::Address);
4080       intptr_t st_offset = 0;
4081       Node* st_base = AddPNode::Ideal_base_and_offset(st_adr, phase, st_offset);
4082 
4083       if (st_base == NULL) {
4084         break; // inscrutable pointer
4085       }
4086 
4087       // Break we have found a store with same base and offset as ours so break
4088       if (st_base == base && st_offset == offset) {
4089         break;
4090       }
4091 
4092       if (st_offset != offset && st_offset != Type::OffsetBot) {
4093         const int MAX_STORE = BytesPerLong;
4094         if (st_offset >= offset + size_in_bytes ||
4095             st_offset <= offset - MAX_STORE ||
4096             st_offset <= offset - mem->as_Store()->memory_size()) {
4097           // Success:  The offsets are provably independent.
4098           // (You may ask, why not just test st_offset != offset and be done?
4099           // The answer is that stores of different sizes can co-exist
4100           // in the same sequence of RawMem effects.  We sometimes initialize
4101           // a whole 'tile' of array elements with a single jint or jlong.)
4102           mem = mem->in(MemNode::Memory);
4103           continue; // advance through independent store memory
4104         }
4105       }
4106 
4107       if (st_base != base
4108           && MemNode::detect_ptr_independence(base, alloc, st_base,
4109                                               AllocateNode::Ideal_allocation(st_base, phase),
4110                                               phase)) {
4111         // Success:  The bases are provably independent.
4112         mem = mem->in(MemNode::Memory);
4113         continue; // advance through independent store memory
4114       }
4115     } else if (mem->is_Proj() && mem->in(0)->is_Initialize()) {
4116 
4117       InitializeNode* st_init = mem->in(0)->as_Initialize();
4118       AllocateNode* st_alloc = st_init->allocation();
4119 
4120       // Make sure that we are looking at the same allocation site.
4121       // The alloc variable is guaranteed to not be null here from earlier check.
4122       if (alloc == st_alloc) {
4123         // Check that the initialization is storing NULL so that no previous store
4124         // has been moved up and directly write a reference
4125         Node* captured_store = st_init->find_captured_store(offset,
4126                                                             type2aelembytes(T_OBJECT),
4127                                                             phase);
4128         if (captured_store == NULL || captured_store == st_init->zero_memory()) {
4129           return true;
4130         }
4131       }
4132     }
4133 
4134     // Unless there is an explicit 'continue', we must bail out here,
4135     // because 'mem' is an inscrutable memory state (e.g., a call).
4136     break;
4137   }
4138 
4139   return false;
4140 }
4141 
4142 // G1 pre/post barriers
4143 void GraphKit::g1_write_barrier_pre(bool do_load,
4144                                     Node* obj,
4145                                     Node* adr,
4146                                     uint alias_idx,
4147                                     Node* val,
4148                                     const TypeOopPtr* val_type,
4149                                     Node* pre_val,
4150                                     BasicType bt) {
4151 
4152   // Some sanity checks
4153   // Note: val is unused in this routine.
4154 
4155   if (do_load) {
4156     // We need to generate the load of the previous value
4157     assert(obj != NULL, "must have a base");
4158     assert(adr != NULL, "where are loading from?");
4159     assert(pre_val == NULL, "loaded already?");
4160     assert(val_type != NULL, "need a type");
4161 
4162     if (use_ReduceInitialCardMarks()
4163         && g1_can_remove_pre_barrier(&_gvn, adr, bt, alias_idx)) {
4164       return;
4165     }
4166 
4167   } else {
4168     // In this case both val_type and alias_idx are unused.
4169     assert(pre_val != NULL, "must be loaded already");
4170     // Nothing to be done if pre_val is null.
4171     if (pre_val->bottom_type() == TypePtr::NULL_PTR) return;
4172     assert(pre_val->bottom_type()->basic_type() == T_OBJECT, "or we shouldn't be here");
4173   }
4174   assert(bt == T_OBJECT || bt == T_VALUETYPE, "or we shouldn't be here");
4175 
4176   IdealKit ideal(this, true);
4177 
4178   Node* tls = __ thread(); // ThreadLocalStorage
4179 
4180   Node* no_ctrl = NULL;
4181   Node* no_base = __ top();
4182   Node* zero  = __ ConI(0);
4183   Node* zeroX = __ ConX(0);
4184 
4185   float likely  = PROB_LIKELY(0.999);
4186   float unlikely  = PROB_UNLIKELY(0.999);
4187 
4188   BasicType active_type = in_bytes(SATBMarkQueue::byte_width_of_active()) == 4 ? T_INT : T_BYTE;
4189   assert(in_bytes(SATBMarkQueue::byte_width_of_active()) == 4 || in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "flag width");
4190 
4191   // Offsets into the thread
4192   const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() +  // 648
4193                                           SATBMarkQueue::byte_offset_of_active());
4194   const int index_offset   = in_bytes(JavaThread::satb_mark_queue_offset() +  // 656
4195                                           SATBMarkQueue::byte_offset_of_index());
4196   const int buffer_offset  = in_bytes(JavaThread::satb_mark_queue_offset() +  // 652
4197                                           SATBMarkQueue::byte_offset_of_buf());
4198 
4199   // Now the actual pointers into the thread
4200   Node* marking_adr = __ AddP(no_base, tls, __ ConX(marking_offset));
4201   Node* buffer_adr  = __ AddP(no_base, tls, __ ConX(buffer_offset));
4202   Node* index_adr   = __ AddP(no_base, tls, __ ConX(index_offset));
4203 
4204   // Now some of the values
4205   Node* marking = __ load(__ ctrl(), marking_adr, TypeInt::INT, active_type, Compile::AliasIdxRaw);
4206 
4207   // if (!marking)
4208   __ if_then(marking, BoolTest::ne, zero, unlikely); {
4209     BasicType index_bt = TypeX_X->basic_type();
4210     assert(sizeof(size_t) == type2aelembytes(index_bt), "Loading G1 SATBMarkQueue::_index with wrong size.");
4211     Node* index   = __ load(__ ctrl(), index_adr, TypeX_X, index_bt, Compile::AliasIdxRaw);
4212 
4213     if (do_load) {
4214       // load original value
4215       // alias_idx correct??
4216       pre_val = __ load(__ ctrl(), adr, val_type, bt, alias_idx);
4217     }
4218 
4219     // if (pre_val != NULL)
4220     __ if_then(pre_val, BoolTest::ne, null()); {
4221       Node* buffer  = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
4222 
4223       // is the queue for this thread full?
4224       __ if_then(index, BoolTest::ne, zeroX, likely); {
4225 
4226         // decrement the index
4227         Node* next_index = _gvn.transform(new SubXNode(index, __ ConX(sizeof(intptr_t))));
4228 
4229         // Now get the buffer location we will log the previous value into and store it
4230         Node *log_addr = __ AddP(no_base, buffer, next_index);
4231         __ store(__ ctrl(), log_addr, pre_val, T_OBJECT, Compile::AliasIdxRaw, MemNode::unordered);
4232         // update the index
4233         __ store(__ ctrl(), index_adr, next_index, index_bt, Compile::AliasIdxRaw, MemNode::unordered);
4234 
4235       } __ else_(); {
4236 
4237         // logging buffer is full, call the runtime
4238         const TypeFunc *tf = OptoRuntime::g1_wb_pre_Type();
4239         __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_pre), "g1_wb_pre", pre_val, tls);
4240       } __ end_if();  // (!index)
4241     } __ end_if();  // (pre_val != NULL)
4242   } __ end_if();  // (!marking)
4243 
4244   // Final sync IdealKit and GraphKit.
4245   final_sync(ideal);
4246 }
4247 
4248 /*
4249  * G1 similar to any GC with a Young Generation requires a way to keep track of
4250  * references from Old Generation to Young Generation to make sure all live
4251  * objects are found. G1 also requires to keep track of object references
4252  * between different regions to enable evacuation of old regions, which is done
4253  * as part of mixed collections. References are tracked in remembered sets and
4254  * is continuously updated as reference are written to with the help of the
4255  * post-barrier.
4256  *
4257  * To reduce the number of updates to the remembered set the post-barrier
4258  * filters updates to fields in objects located in the Young Generation,
4259  * the same region as the reference, when the NULL is being written or
4260  * if the card is already marked as dirty by an earlier write.
4261  *
4262  * Under certain circumstances it is possible to avoid generating the
4263  * post-barrier completely if it is possible during compile time to prove
4264  * the object is newly allocated and that no safepoint exists between the
4265  * allocation and the store.
4266  *
4267  * In the case of slow allocation the allocation code must handle the barrier
4268  * as part of the allocation in the case the allocated object is not located
4269  * in the nursery, this would happen for humongous objects. This is similar to
4270  * how CMS is required to handle this case, see the comments for the method
4271  * CollectedHeap::new_store_pre_barrier and OptoRuntime::new_store_pre_barrier.
4272  * A deferred card mark is required for these objects and handled in the above
4273  * mentioned methods.
4274  *
4275  * Returns true if the post barrier can be removed
4276  */
4277 bool GraphKit::g1_can_remove_post_barrier(PhaseTransform* phase, Node* store,
4278                                           Node* adr) {
4279   intptr_t      offset = 0;
4280   Node*         base   = AddPNode::Ideal_base_and_offset(adr, phase, offset);
4281   AllocateNode* alloc  = AllocateNode::Ideal_allocation(base, phase);
4282 
4283   if (offset == Type::OffsetBot) {
4284     return false; // cannot unalias unless there are precise offsets
4285   }
4286 
4287   if (alloc == NULL) {
4288      return false; // No allocation found
4289   }
4290 
4291   // Start search from Store node
4292   Node* mem = store->in(MemNode::Control);
4293   if (mem->is_Proj() && mem->in(0)->is_Initialize()) {
4294 
4295     InitializeNode* st_init = mem->in(0)->as_Initialize();
4296     AllocateNode*  st_alloc = st_init->allocation();
4297 
4298     // Make sure we are looking at the same allocation
4299     if (alloc == st_alloc) {
4300       return true;
4301     }
4302   }
4303 
4304   return false;
4305 }
4306 
4307 //
4308 // Update the card table and add card address to the queue
4309 //
4310 void GraphKit::g1_mark_card(IdealKit& ideal,
4311                             Node* card_adr,
4312                             Node* oop_store,
4313                             uint oop_alias_idx,
4314                             Node* index,
4315                             Node* index_adr,
4316                             Node* buffer,
4317                             const TypeFunc* tf) {
4318 
4319   Node* zero  = __ ConI(0);
4320   Node* zeroX = __ ConX(0);
4321   Node* no_base = __ top();
4322   BasicType card_bt = T_BYTE;
4323   // Smash zero into card. MUST BE ORDERED WRT TO STORE
4324   __ storeCM(__ ctrl(), card_adr, zero, oop_store, oop_alias_idx, card_bt, Compile::AliasIdxRaw);
4325 
4326   //  Now do the queue work
4327   __ if_then(index, BoolTest::ne, zeroX); {
4328 
4329     Node* next_index = _gvn.transform(new SubXNode(index, __ ConX(sizeof(intptr_t))));
4330     Node* log_addr = __ AddP(no_base, buffer, next_index);
4331 
4332     // Order, see storeCM.
4333     __ store(__ ctrl(), log_addr, card_adr, T_ADDRESS, Compile::AliasIdxRaw, MemNode::unordered);
4334     __ store(__ ctrl(), index_adr, next_index, TypeX_X->basic_type(), Compile::AliasIdxRaw, MemNode::unordered);
4335 
4336   } __ else_(); {
4337     __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_post), "g1_wb_post", card_adr, __ thread());
4338   } __ end_if();
4339 
4340 }
4341 
4342 void GraphKit::g1_write_barrier_post(Node* oop_store,
4343                                      Node* obj,
4344                                      Node* adr,
4345                                      uint alias_idx,
4346                                      Node* val,
4347                                      BasicType bt,
4348                                      bool use_precise) {
4349   // If we are writing a NULL then we need no post barrier
4350 
4351   if (val != NULL && val->is_Con() && val->bottom_type() == TypePtr::NULL_PTR) {
4352     // Must be NULL
4353     const Type* t = val->bottom_type();
4354     assert(t == Type::TOP || t == TypePtr::NULL_PTR, "must be NULL");
4355     // No post barrier if writing NULLx
4356     return;
4357   }
4358 
4359   if (use_ReduceInitialCardMarks() && obj == just_allocated_object(control())) {
4360     // We can skip marks on a freshly-allocated object in Eden.
4361     // Keep this code in sync with new_store_pre_barrier() in runtime.cpp.
4362     // That routine informs GC to take appropriate compensating steps,
4363     // upon a slow-path allocation, so as to make this card-mark
4364     // elision safe.
4365     return;
4366   }
4367 
4368   if (use_ReduceInitialCardMarks()
4369       && g1_can_remove_post_barrier(&_gvn, oop_store, adr)) {
4370     return;
4371   }
4372 
4373   if (!use_precise) {
4374     // All card marks for a (non-array) instance are in one place:
4375     adr = obj;
4376   }
4377   // (Else it's an array (or unknown), and we want more precise card marks.)
4378   assert(adr != NULL, "");
4379 
4380   IdealKit ideal(this, true);
4381 
4382   Node* tls = __ thread(); // ThreadLocalStorage
4383 
4384   Node* no_base = __ top();
4385   float likely  = PROB_LIKELY(0.999);
4386   float unlikely  = PROB_UNLIKELY(0.999);
4387   Node* young_card = __ ConI((jint)G1SATBCardTableModRefBS::g1_young_card_val());
4388   Node* dirty_card = __ ConI((jint)CardTableModRefBS::dirty_card_val());
4389   Node* zeroX = __ ConX(0);
4390 
4391   // Get the alias_index for raw card-mark memory
4392   const TypePtr* card_type = TypeRawPtr::BOTTOM;
4393 
4394   const TypeFunc *tf = OptoRuntime::g1_wb_post_Type();
4395 
4396   // Offsets into the thread
4397   const int index_offset  = in_bytes(JavaThread::dirty_card_queue_offset() +
4398                                      DirtyCardQueue::byte_offset_of_index());
4399   const int buffer_offset = in_bytes(JavaThread::dirty_card_queue_offset() +
4400                                      DirtyCardQueue::byte_offset_of_buf());
4401 
4402   // Pointers into the thread
4403 
4404   Node* buffer_adr = __ AddP(no_base, tls, __ ConX(buffer_offset));
4405   Node* index_adr =  __ AddP(no_base, tls, __ ConX(index_offset));
4406 
4407   // Now some values
4408   // Use ctrl to avoid hoisting these values past a safepoint, which could
4409   // potentially reset these fields in the JavaThread.
4410   Node* index  = __ load(__ ctrl(), index_adr, TypeX_X, TypeX_X->basic_type(), Compile::AliasIdxRaw);
4411   Node* buffer = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
4412 
4413   // Convert the store obj pointer to an int prior to doing math on it
4414   // Must use ctrl to prevent "integerized oop" existing across safepoint
4415   Node* cast =  __ CastPX(__ ctrl(), adr);
4416 
4417   // Divide pointer by card size
4418   Node* card_offset = __ URShiftX( cast, __ ConI(CardTableModRefBS::card_shift) );
4419 
4420   // Combine card table base and card offset
4421   Node* card_adr = __ AddP(no_base, byte_map_base_node(), card_offset );
4422 
4423   // If we know the value being stored does it cross regions?
4424 
4425   if (val != NULL) {
4426     // Does the store cause us to cross regions?
4427 
4428     // Should be able to do an unsigned compare of region_size instead of
4429     // and extra shift. Do we have an unsigned compare??
4430     // Node* region_size = __ ConI(1 << HeapRegion::LogOfHRGrainBytes);
4431     Node* xor_res =  __ URShiftX ( __ XorX( cast,  __ CastPX(__ ctrl(), val)), __ ConI(HeapRegion::LogOfHRGrainBytes));
4432 
4433     // if (xor_res == 0) same region so skip
4434     __ if_then(xor_res, BoolTest::ne, zeroX); {
4435 
4436       // No barrier if we are storing a NULL
4437       __ if_then(val, BoolTest::ne, null(), unlikely); {
4438 
4439         // Ok must mark the card if not already dirty
4440 
4441         // load the original value of the card
4442         Node* card_val = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
4443 
4444         __ if_then(card_val, BoolTest::ne, young_card); {
4445           sync_kit(ideal);
4446           insert_store_load_for_barrier();
4447           __ sync_kit(this);
4448 
4449           Node* card_val_reload = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
4450           __ if_then(card_val_reload, BoolTest::ne, dirty_card); {
4451             g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
4452           } __ end_if();
4453         } __ end_if();
4454       } __ end_if();
4455     } __ end_if();
4456   } else {
4457     // Object.clone() instrinsic uses this path.
4458     g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
4459   }
4460 
4461   // Final sync IdealKit and GraphKit.
4462   final_sync(ideal);
4463 }
4464 #undef __
4465 
4466 
4467 Node* GraphKit::load_String_length(Node* ctrl, Node* str) {
4468   Node* len = load_array_length(load_String_value(ctrl, str));
4469   Node* coder = load_String_coder(ctrl, str);
4470   // Divide length by 2 if coder is UTF16
4471   return _gvn.transform(new RShiftINode(len, coder));
4472 }
4473 
4474 Node* GraphKit::load_String_value(Node* ctrl, Node* str) {
4475   int value_offset = java_lang_String::value_offset_in_bytes();
4476   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4477                                                      false, NULL, Type::Offset(0));
4478   const TypePtr* value_field_type = string_type->add_offset(value_offset);
4479   const TypeAryPtr* value_type = TypeAryPtr::make(TypePtr::NotNull,
4480                                                   TypeAry::make(TypeInt::BYTE, TypeInt::POS),
4481                                                   ciTypeArrayKlass::make(T_BYTE), true, Type::Offset(0));
4482   int value_field_idx = C->get_alias_index(value_field_type);
4483   Node* load = make_load(ctrl, basic_plus_adr(str, str, value_offset),
4484                          value_type, T_OBJECT, value_field_idx, MemNode::unordered);
4485   // String.value field is known to be @Stable.
4486   if (UseImplicitStableValues) {
4487     load = cast_array_to_stable(load, value_type);
4488   }
4489   return load;
4490 }
4491 
4492 Node* GraphKit::load_String_coder(Node* ctrl, Node* str) {
4493   if (java_lang_String::has_coder_field()) {
4494     if (!CompactStrings) {
4495       return intcon(java_lang_String::CODER_UTF16);
4496     }
4497     int coder_offset = java_lang_String::coder_offset_in_bytes();
4498     const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4499                                                        false, NULL, Type::Offset(0));
4500     const TypePtr* coder_field_type = string_type->add_offset(coder_offset);
4501     int coder_field_idx = C->get_alias_index(coder_field_type);
4502     return make_load(ctrl, basic_plus_adr(str, str, coder_offset),
4503                      TypeInt::BYTE, T_BYTE, coder_field_idx, MemNode::unordered);
4504   } else {
4505     return intcon(0); // false
4506   }
4507 }
4508 
4509 void GraphKit::store_String_value(Node* ctrl, Node* str, Node* value) {
4510   int value_offset = java_lang_String::value_offset_in_bytes();
4511   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4512                                                      false, NULL, Type::Offset(0));
4513   const TypePtr* value_field_type = string_type->add_offset(value_offset);
4514   store_oop_to_object(ctrl, str,  basic_plus_adr(str, value_offset), value_field_type,
4515       value, TypeAryPtr::BYTES, T_OBJECT, MemNode::unordered);
4516 }
4517 
4518 void GraphKit::store_String_coder(Node* ctrl, Node* str, Node* value) {
4519   int coder_offset = java_lang_String::coder_offset_in_bytes();
4520   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4521                                                      false, NULL, Type::Offset(0));
4522   const TypePtr* coder_field_type = string_type->add_offset(coder_offset);
4523   int coder_field_idx = C->get_alias_index(coder_field_type);
4524   store_to_memory(ctrl, basic_plus_adr(str, coder_offset),
4525                   value, T_BYTE, coder_field_idx, MemNode::unordered);
4526 }
4527 
4528 // Capture src and dst memory state with a MergeMemNode
4529 Node* GraphKit::capture_memory(const TypePtr* src_type, const TypePtr* dst_type) {
4530   if (src_type == dst_type) {
4531     // Types are equal, we don't need a MergeMemNode
4532     return memory(src_type);
4533   }
4534   MergeMemNode* merge = MergeMemNode::make(map()->memory());
4535   record_for_igvn(merge); // fold it up later, if possible
4536   int src_idx = C->get_alias_index(src_type);
4537   int dst_idx = C->get_alias_index(dst_type);
4538   merge->set_memory_at(src_idx, memory(src_idx));
4539   merge->set_memory_at(dst_idx, memory(dst_idx));
4540   return merge;
4541 }
4542 
4543 Node* GraphKit::compress_string(Node* src, const TypeAryPtr* src_type, Node* dst, Node* count) {
4544   assert(Matcher::match_rule_supported(Op_StrCompressedCopy), "Intrinsic not supported");
4545   assert(src_type == TypeAryPtr::BYTES || src_type == TypeAryPtr::CHARS, "invalid source type");
4546   // If input and output memory types differ, capture both states to preserve
4547   // the dependency between preceding and subsequent loads/stores.
4548   // For example, the following program:
4549   //  StoreB
4550   //  compress_string
4551   //  LoadB
4552   // has this memory graph (use->def):
4553   //  LoadB -> compress_string -> CharMem
4554   //             ... -> StoreB -> ByteMem
4555   // The intrinsic hides the dependency between LoadB and StoreB, causing
4556   // the load to read from memory not containing the result of the StoreB.
4557   // The correct memory graph should look like this:
4558   //  LoadB -> compress_string -> MergeMem(CharMem, StoreB(ByteMem))
4559   Node* mem = capture_memory(src_type, TypeAryPtr::BYTES);
4560   StrCompressedCopyNode* str = new StrCompressedCopyNode(control(), mem, src, dst, count);
4561   Node* res_mem = _gvn.transform(new SCMemProjNode(str));
4562   set_memory(res_mem, TypeAryPtr::BYTES);
4563   return str;
4564 }
4565 
4566 void GraphKit::inflate_string(Node* src, Node* dst, const TypeAryPtr* dst_type, Node* count) {
4567   assert(Matcher::match_rule_supported(Op_StrInflatedCopy), "Intrinsic not supported");
4568   assert(dst_type == TypeAryPtr::BYTES || dst_type == TypeAryPtr::CHARS, "invalid dest type");
4569   // Capture src and dst memory (see comment in 'compress_string').
4570   Node* mem = capture_memory(TypeAryPtr::BYTES, dst_type);
4571   StrInflatedCopyNode* str = new StrInflatedCopyNode(control(), mem, src, dst, count);
4572   set_memory(_gvn.transform(str), dst_type);
4573 }
4574 
4575 void GraphKit::inflate_string_slow(Node* src, Node* dst, Node* start, Node* count) {
4576   /**
4577    * int i_char = start;
4578    * for (int i_byte = 0; i_byte < count; i_byte++) {
4579    *   dst[i_char++] = (char)(src[i_byte] & 0xff);
4580    * }
4581    */
4582   add_predicate();
4583   RegionNode* head = new RegionNode(3);
4584   head->init_req(1, control());
4585   gvn().set_type(head, Type::CONTROL);
4586   record_for_igvn(head);
4587 
4588   Node* i_byte = new PhiNode(head, TypeInt::INT);
4589   i_byte->init_req(1, intcon(0));
4590   gvn().set_type(i_byte, TypeInt::INT);
4591   record_for_igvn(i_byte);
4592 
4593   Node* i_char = new PhiNode(head, TypeInt::INT);
4594   i_char->init_req(1, start);
4595   gvn().set_type(i_char, TypeInt::INT);
4596   record_for_igvn(i_char);
4597 
4598   Node* mem = PhiNode::make(head, memory(TypeAryPtr::BYTES), Type::MEMORY, TypeAryPtr::BYTES);
4599   gvn().set_type(mem, Type::MEMORY);
4600   record_for_igvn(mem);
4601   set_control(head);
4602   set_memory(mem, TypeAryPtr::BYTES);
4603   Node* ch = load_array_element(control(), src, i_byte, TypeAryPtr::BYTES);
4604   Node* st = store_to_memory(control(), array_element_address(dst, i_char, T_BYTE),
4605                              AndI(ch, intcon(0xff)), T_CHAR, TypeAryPtr::BYTES, MemNode::unordered,
4606                              false, false, true /* mismatched */);
4607 
4608   IfNode* iff = create_and_map_if(head, Bool(CmpI(i_byte, count), BoolTest::lt), PROB_FAIR, COUNT_UNKNOWN);
4609   head->init_req(2, IfTrue(iff));
4610   mem->init_req(2, st);
4611   i_byte->init_req(2, AddI(i_byte, intcon(1)));
4612   i_char->init_req(2, AddI(i_char, intcon(2)));
4613 
4614   set_control(IfFalse(iff));
4615   set_memory(st, TypeAryPtr::BYTES);
4616 }
4617 
4618 Node* GraphKit::cast_array_to_stable(Node* ary, const TypeAryPtr* ary_type) {
4619   // Reify the property as a CastPP node in Ideal graph to comply with monotonicity
4620   // assumption of CCP analysis.
4621   return _gvn.transform(new CastPPNode(ary, ary_type->cast_to_stable(true)));
4622 }