1 /*
   2  * Copyright (c) 2001, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "compiler/compileLog.hpp"
  27 #include "gc/g1/g1SATBCardTableModRefBS.hpp"
  28 #include "gc/g1/heapRegion.hpp"
  29 #include "gc/shared/barrierSet.hpp"
  30 #include "gc/shared/cardTableModRefBS.hpp"
  31 #include "gc/shared/collectedHeap.hpp"
  32 #include "memory/resourceArea.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/narrowptrnode.hpp"
  42 #include "opto/opaquenode.hpp"
  43 #include "opto/parse.hpp"
  44 #include "opto/rootnode.hpp"
  45 #include "opto/runtime.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     default:
 589       break;
 590     }
 591     if (failing()) { stop(); return; }  // exception allocation might fail
 592     if (ex_obj != NULL) {
 593       // Cheat with a preallocated exception object.
 594       if (C->log() != NULL)
 595         C->log()->elem("hot_throw preallocated='1' reason='%s'",
 596                        Deoptimization::trap_reason_name(reason));
 597       const TypeInstPtr* ex_con  = TypeInstPtr::make(ex_obj);
 598       Node*              ex_node = _gvn.transform(ConNode::make(ex_con));
 599 
 600       // Clear the detail message of the preallocated exception object.
 601       // Weblogic sometimes mutates the detail message of exceptions
 602       // using reflection.
 603       int offset = java_lang_Throwable::get_detailMessage_offset();
 604       const TypePtr* adr_typ = ex_con->add_offset(offset);
 605 
 606       Node *adr = basic_plus_adr(ex_node, ex_node, offset);
 607       const TypeOopPtr* val_type = TypeOopPtr::make_from_klass(env()->String_klass());
 608       // Conservatively release stores of object references.
 609       Node *store = store_oop_to_object(control(), ex_node, adr, adr_typ, null(), val_type, T_OBJECT, MemNode::release);
 610 
 611       add_exception_state(make_exception_state(ex_node));
 612       return;
 613     }
 614   }
 615 
 616   // %%% Maybe add entry to OptoRuntime which directly throws the exc.?
 617   // It won't be much cheaper than bailing to the interp., since we'll
 618   // have to pass up all the debug-info, and the runtime will have to
 619   // create the stack trace.
 620 
 621   // Usual case:  Bail to interpreter.
 622   // Reserve the right to recompile if we haven't seen anything yet.
 623 
 624   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? C->method() : NULL;
 625   Deoptimization::DeoptAction action = Deoptimization::Action_maybe_recompile;
 626   if (treat_throw_as_hot
 627       && (method()->method_data()->trap_recompiled_at(bci(), m)
 628           || C->too_many_traps(reason))) {
 629     // We cannot afford to take more traps here.  Suffer in the interpreter.
 630     if (C->log() != NULL)
 631       C->log()->elem("hot_throw preallocated='0' reason='%s' mcount='%d'",
 632                      Deoptimization::trap_reason_name(reason),
 633                      C->trap_count(reason));
 634     action = Deoptimization::Action_none;
 635   }
 636 
 637   // "must_throw" prunes the JVM state to include only the stack, if there
 638   // are no local exception handlers.  This should cut down on register
 639   // allocation time and code size, by drastically reducing the number
 640   // of in-edges on the call to the uncommon trap.
 641 
 642   uncommon_trap(reason, action, (ciKlass*)NULL, (char*)NULL, must_throw);
 643 }
 644 
 645 
 646 //----------------------------PreserveJVMState---------------------------------
 647 PreserveJVMState::PreserveJVMState(GraphKit* kit, bool clone_map) {
 648   debug_only(kit->verify_map());
 649   _kit    = kit;
 650   _map    = kit->map();   // preserve the map
 651   _sp     = kit->sp();
 652   kit->set_map(clone_map ? kit->clone_map() : NULL);
 653 #ifdef ASSERT
 654   _bci    = kit->bci();
 655   Parse* parser = kit->is_Parse();
 656   int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo();
 657   _block  = block;
 658 #endif
 659 }
 660 PreserveJVMState::~PreserveJVMState() {
 661   GraphKit* kit = _kit;
 662 #ifdef ASSERT
 663   assert(kit->bci() == _bci, "bci must not shift");
 664   Parse* parser = kit->is_Parse();
 665   int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo();
 666   assert(block == _block,    "block must not shift");
 667 #endif
 668   kit->set_map(_map);
 669   kit->set_sp(_sp);
 670 }
 671 
 672 
 673 //-----------------------------BuildCutout-------------------------------------
 674 BuildCutout::BuildCutout(GraphKit* kit, Node* p, float prob, float cnt)
 675   : PreserveJVMState(kit)
 676 {
 677   assert(p->is_Con() || p->is_Bool(), "test must be a bool");
 678   SafePointNode* outer_map = _map;   // preserved map is caller's
 679   SafePointNode* inner_map = kit->map();
 680   IfNode* iff = kit->create_and_map_if(outer_map->control(), p, prob, cnt);
 681   outer_map->set_control(kit->gvn().transform( new IfTrueNode(iff) ));
 682   inner_map->set_control(kit->gvn().transform( new IfFalseNode(iff) ));
 683 }
 684 BuildCutout::~BuildCutout() {
 685   GraphKit* kit = _kit;
 686   assert(kit->stopped(), "cutout code must stop, throw, return, etc.");
 687 }
 688 
 689 //---------------------------PreserveReexecuteState----------------------------
 690 PreserveReexecuteState::PreserveReexecuteState(GraphKit* kit) {
 691   assert(!kit->stopped(), "must call stopped() before");
 692   _kit    =    kit;
 693   _sp     =    kit->sp();
 694   _reexecute = kit->jvms()->_reexecute;
 695 }
 696 PreserveReexecuteState::~PreserveReexecuteState() {
 697   if (_kit->stopped()) return;
 698   _kit->jvms()->_reexecute = _reexecute;
 699   _kit->set_sp(_sp);
 700 }
 701 
 702 //------------------------------clone_map--------------------------------------
 703 // Implementation of PreserveJVMState
 704 //
 705 // Only clone_map(...) here. If this function is only used in the
 706 // PreserveJVMState class we may want to get rid of this extra
 707 // function eventually and do it all there.
 708 
 709 SafePointNode* GraphKit::clone_map() {
 710   if (map() == NULL)  return NULL;
 711 
 712   // Clone the memory edge first
 713   Node* mem = MergeMemNode::make(map()->memory());
 714   gvn().set_type_bottom(mem);
 715 
 716   SafePointNode *clonemap = (SafePointNode*)map()->clone();
 717   JVMState* jvms = this->jvms();
 718   JVMState* clonejvms = jvms->clone_shallow(C);
 719   clonemap->set_memory(mem);
 720   clonemap->set_jvms(clonejvms);
 721   clonejvms->set_map(clonemap);
 722   record_for_igvn(clonemap);
 723   gvn().set_type_bottom(clonemap);
 724   return clonemap;
 725 }
 726 
 727 
 728 //-----------------------------set_map_clone-----------------------------------
 729 void GraphKit::set_map_clone(SafePointNode* m) {
 730   _map = m;
 731   _map = clone_map();
 732   _map->set_next_exception(NULL);
 733   debug_only(verify_map());
 734 }
 735 
 736 
 737 //----------------------------kill_dead_locals---------------------------------
 738 // Detect any locals which are known to be dead, and force them to top.
 739 void GraphKit::kill_dead_locals() {
 740   // Consult the liveness information for the locals.  If any
 741   // of them are unused, then they can be replaced by top().  This
 742   // should help register allocation time and cut down on the size
 743   // of the deoptimization information.
 744 
 745   // This call is made from many of the bytecode handling
 746   // subroutines called from the Big Switch in do_one_bytecode.
 747   // Every bytecode which might include a slow path is responsible
 748   // for killing its dead locals.  The more consistent we
 749   // are about killing deads, the fewer useless phis will be
 750   // constructed for them at various merge points.
 751 
 752   // bci can be -1 (InvocationEntryBci).  We return the entry
 753   // liveness for the method.
 754 
 755   if (method() == NULL || method()->code_size() == 0) {
 756     // We are building a graph for a call to a native method.
 757     // All locals are live.
 758     return;
 759   }
 760 
 761   ResourceMark rm;
 762 
 763   // Consult the liveness information for the locals.  If any
 764   // of them are unused, then they can be replaced by top().  This
 765   // should help register allocation time and cut down on the size
 766   // of the deoptimization information.
 767   MethodLivenessResult live_locals = method()->liveness_at_bci(bci());
 768 
 769   int len = (int)live_locals.size();
 770   assert(len <= jvms()->loc_size(), "too many live locals");
 771   for (int local = 0; local < len; local++) {
 772     if (!live_locals.at(local)) {
 773       set_local(local, top());
 774     }
 775   }
 776 }
 777 
 778 #ifdef ASSERT
 779 //-------------------------dead_locals_are_killed------------------------------
 780 // Return true if all dead locals are set to top in the map.
 781 // Used to assert "clean" debug info at various points.
 782 bool GraphKit::dead_locals_are_killed() {
 783   if (method() == NULL || method()->code_size() == 0) {
 784     // No locals need to be dead, so all is as it should be.
 785     return true;
 786   }
 787 
 788   // Make sure somebody called kill_dead_locals upstream.
 789   ResourceMark rm;
 790   for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) {
 791     if (jvms->loc_size() == 0)  continue;  // no locals to consult
 792     SafePointNode* map = jvms->map();
 793     ciMethod* method = jvms->method();
 794     int       bci    = jvms->bci();
 795     if (jvms == this->jvms()) {
 796       bci = this->bci();  // it might not yet be synched
 797     }
 798     MethodLivenessResult live_locals = method->liveness_at_bci(bci);
 799     int len = (int)live_locals.size();
 800     if (!live_locals.is_valid() || len == 0)
 801       // This method is trivial, or is poisoned by a breakpoint.
 802       return true;
 803     assert(len == jvms->loc_size(), "live map consistent with locals map");
 804     for (int local = 0; local < len; local++) {
 805       if (!live_locals.at(local) && map->local(jvms, local) != top()) {
 806         if (PrintMiscellaneous && (Verbose || WizardMode)) {
 807           tty->print_cr("Zombie local %d: ", local);
 808           jvms->dump();
 809         }
 810         return false;
 811       }
 812     }
 813   }
 814   return true;
 815 }
 816 
 817 #endif //ASSERT
 818 
 819 // Helper function for enforcing certain bytecodes to reexecute if
 820 // deoptimization happens
 821 static bool should_reexecute_implied_by_bytecode(JVMState *jvms, bool is_anewarray) {
 822   ciMethod* cur_method = jvms->method();
 823   int       cur_bci   = jvms->bci();
 824   if (cur_method != NULL && cur_bci != InvocationEntryBci) {
 825     Bytecodes::Code code = cur_method->java_code_at_bci(cur_bci);
 826     return Interpreter::bytecode_should_reexecute(code) ||
 827            (is_anewarray && code == Bytecodes::_multianewarray);
 828     // Reexecute _multianewarray bytecode which was replaced with
 829     // sequence of [a]newarray. See Parse::do_multianewarray().
 830     //
 831     // Note: interpreter should not have it set since this optimization
 832     // is limited by dimensions and guarded by flag so in some cases
 833     // multianewarray() runtime calls will be generated and
 834     // the bytecode should not be reexecutes (stack will not be reset).
 835   } else
 836     return false;
 837 }
 838 
 839 // Helper function for adding JVMState and debug information to node
 840 void GraphKit::add_safepoint_edges(SafePointNode* call, bool must_throw) {
 841   // Add the safepoint edges to the call (or other safepoint).
 842 
 843   // Make sure dead locals are set to top.  This
 844   // should help register allocation time and cut down on the size
 845   // of the deoptimization information.
 846   assert(dead_locals_are_killed(), "garbage in debug info before safepoint");
 847 
 848   // Walk the inline list to fill in the correct set of JVMState's
 849   // Also fill in the associated edges for each JVMState.
 850 
 851   // If the bytecode needs to be reexecuted we need to put
 852   // the arguments back on the stack.
 853   const bool should_reexecute = jvms()->should_reexecute();
 854   JVMState* youngest_jvms = should_reexecute ? sync_jvms_for_reexecute() : sync_jvms();
 855 
 856   // NOTE: set_bci (called from sync_jvms) might reset the reexecute bit to
 857   // undefined if the bci is different.  This is normal for Parse but it
 858   // should not happen for LibraryCallKit because only one bci is processed.
 859   assert(!is_LibraryCallKit() || (jvms()->should_reexecute() == should_reexecute),
 860          "in LibraryCallKit the reexecute bit should not change");
 861 
 862   // If we are guaranteed to throw, we can prune everything but the
 863   // input to the current bytecode.
 864   bool can_prune_locals = false;
 865   uint stack_slots_not_pruned = 0;
 866   int inputs = 0, depth = 0;
 867   if (must_throw) {
 868     assert(method() == youngest_jvms->method(), "sanity");
 869     if (compute_stack_effects(inputs, depth)) {
 870       can_prune_locals = true;
 871       stack_slots_not_pruned = inputs;
 872     }
 873   }
 874 
 875   if (env()->should_retain_local_variables()) {
 876     // At any safepoint, this method can get breakpointed, which would
 877     // then require an immediate deoptimization.
 878     can_prune_locals = false;  // do not prune locals
 879     stack_slots_not_pruned = 0;
 880   }
 881 
 882   // do not scribble on the input jvms
 883   JVMState* out_jvms = youngest_jvms->clone_deep(C);
 884   call->set_jvms(out_jvms); // Start jvms list for call node
 885 
 886   // For a known set of bytecodes, the interpreter should reexecute them if
 887   // deoptimization happens. We set the reexecute state for them here
 888   if (out_jvms->is_reexecute_undefined() && //don't change if already specified
 889       should_reexecute_implied_by_bytecode(out_jvms, call->is_AllocateArray())) {
 890     out_jvms->set_should_reexecute(true); //NOTE: youngest_jvms not changed
 891   }
 892 
 893   // Presize the call:
 894   DEBUG_ONLY(uint non_debug_edges = call->req());
 895   call->add_req_batch(top(), youngest_jvms->debug_depth());
 896   assert(call->req() == non_debug_edges + youngest_jvms->debug_depth(), "");
 897 
 898   // Set up edges so that the call looks like this:
 899   //  Call [state:] ctl io mem fptr retadr
 900   //       [parms:] parm0 ... parmN
 901   //       [root:]  loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN
 902   //    [...mid:]   loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN [...]
 903   //       [young:] loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN
 904   // Note that caller debug info precedes callee debug info.
 905 
 906   // Fill pointer walks backwards from "young:" to "root:" in the diagram above:
 907   uint debug_ptr = call->req();
 908 
 909   // Loop over the map input edges associated with jvms, add them
 910   // to the call node, & reset all offsets to match call node array.
 911   for (JVMState* in_jvms = youngest_jvms; in_jvms != NULL; ) {
 912     uint debug_end   = debug_ptr;
 913     uint debug_start = debug_ptr - in_jvms->debug_size();
 914     debug_ptr = debug_start;  // back up the ptr
 915 
 916     uint p = debug_start;  // walks forward in [debug_start, debug_end)
 917     uint j, k, l;
 918     SafePointNode* in_map = in_jvms->map();
 919     out_jvms->set_map(call);
 920 
 921     if (can_prune_locals) {
 922       assert(in_jvms->method() == out_jvms->method(), "sanity");
 923       // If the current throw can reach an exception handler in this JVMS,
 924       // then we must keep everything live that can reach that handler.
 925       // As a quick and dirty approximation, we look for any handlers at all.
 926       if (in_jvms->method()->has_exception_handlers()) {
 927         can_prune_locals = false;
 928       }
 929     }
 930 
 931     // Add the Locals
 932     k = in_jvms->locoff();
 933     l = in_jvms->loc_size();
 934     out_jvms->set_locoff(p);
 935     if (!can_prune_locals) {
 936       for (j = 0; j < l; j++)
 937         call->set_req(p++, in_map->in(k+j));
 938     } else {
 939       p += l;  // already set to top above by add_req_batch
 940     }
 941 
 942     // Add the Expression Stack
 943     k = in_jvms->stkoff();
 944     l = in_jvms->sp();
 945     out_jvms->set_stkoff(p);
 946     if (!can_prune_locals) {
 947       for (j = 0; j < l; j++)
 948         call->set_req(p++, in_map->in(k+j));
 949     } else if (can_prune_locals && stack_slots_not_pruned != 0) {
 950       // Divide stack into {S0,...,S1}, where S0 is set to top.
 951       uint s1 = stack_slots_not_pruned;
 952       stack_slots_not_pruned = 0;  // for next iteration
 953       if (s1 > l)  s1 = l;
 954       uint s0 = l - s1;
 955       p += s0;  // skip the tops preinstalled by add_req_batch
 956       for (j = s0; j < l; j++)
 957         call->set_req(p++, in_map->in(k+j));
 958     } else {
 959       p += l;  // already set to top above by add_req_batch
 960     }
 961 
 962     // Add the Monitors
 963     k = in_jvms->monoff();
 964     l = in_jvms->mon_size();
 965     out_jvms->set_monoff(p);
 966     for (j = 0; j < l; j++)
 967       call->set_req(p++, in_map->in(k+j));
 968 
 969     // Copy any scalar object fields.
 970     k = in_jvms->scloff();
 971     l = in_jvms->scl_size();
 972     out_jvms->set_scloff(p);
 973     for (j = 0; j < l; j++)
 974       call->set_req(p++, in_map->in(k+j));
 975 
 976     // Finish the new jvms.
 977     out_jvms->set_endoff(p);
 978 
 979     assert(out_jvms->endoff()     == debug_end,             "fill ptr must match");
 980     assert(out_jvms->depth()      == in_jvms->depth(),      "depth must match");
 981     assert(out_jvms->loc_size()   == in_jvms->loc_size(),   "size must match");
 982     assert(out_jvms->mon_size()   == in_jvms->mon_size(),   "size must match");
 983     assert(out_jvms->scl_size()   == in_jvms->scl_size(),   "size must match");
 984     assert(out_jvms->debug_size() == in_jvms->debug_size(), "size must match");
 985 
 986     // Update the two tail pointers in parallel.
 987     out_jvms = out_jvms->caller();
 988     in_jvms  = in_jvms->caller();
 989   }
 990 
 991   assert(debug_ptr == non_debug_edges, "debug info must fit exactly");
 992 
 993   // Test the correctness of JVMState::debug_xxx accessors:
 994   assert(call->jvms()->debug_start() == non_debug_edges, "");
 995   assert(call->jvms()->debug_end()   == call->req(), "");
 996   assert(call->jvms()->debug_depth() == call->req() - non_debug_edges, "");
 997 }
 998 
 999 bool GraphKit::compute_stack_effects(int& inputs, int& depth) {
1000   Bytecodes::Code code = java_bc();
1001   if (code == Bytecodes::_wide) {
1002     code = method()->java_code_at_bci(bci() + 1);
1003   }
1004 
1005   BasicType rtype = T_ILLEGAL;
1006   int       rsize = 0;
1007 
1008   if (code != Bytecodes::_illegal) {
1009     depth = Bytecodes::depth(code); // checkcast=0, athrow=-1
1010     rtype = Bytecodes::result_type(code); // checkcast=P, athrow=V
1011     if (rtype < T_CONFLICT)
1012       rsize = type2size[rtype];
1013   }
1014 
1015   switch (code) {
1016   case Bytecodes::_illegal:
1017     return false;
1018 
1019   case Bytecodes::_ldc:
1020   case Bytecodes::_ldc_w:
1021   case Bytecodes::_ldc2_w:
1022     inputs = 0;
1023     break;
1024 
1025   case Bytecodes::_dup:         inputs = 1;  break;
1026   case Bytecodes::_dup_x1:      inputs = 2;  break;
1027   case Bytecodes::_dup_x2:      inputs = 3;  break;
1028   case Bytecodes::_dup2:        inputs = 2;  break;
1029   case Bytecodes::_dup2_x1:     inputs = 3;  break;
1030   case Bytecodes::_dup2_x2:     inputs = 4;  break;
1031   case Bytecodes::_swap:        inputs = 2;  break;
1032   case Bytecodes::_arraylength: inputs = 1;  break;
1033 
1034   case Bytecodes::_getstatic:
1035   case Bytecodes::_putstatic:
1036   case Bytecodes::_getfield:
1037   case Bytecodes::_putfield:
1038     {
1039       bool ignored_will_link;
1040       ciField* field = method()->get_field_at_bci(bci(), ignored_will_link);
1041       int      size  = field->type()->size();
1042       bool is_get = (depth >= 0), is_static = (depth & 1);
1043       inputs = (is_static ? 0 : 1);
1044       if (is_get) {
1045         depth = size - inputs;
1046       } else {
1047         inputs += size;        // putxxx pops the value from the stack
1048         depth = - inputs;
1049       }
1050     }
1051     break;
1052 
1053   case Bytecodes::_invokevirtual:
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::_ireturn:
1081   case Bytecodes::_lreturn:
1082   case Bytecodes::_freturn:
1083   case Bytecodes::_dreturn:
1084   case Bytecodes::_areturn:
1085     assert(rsize == -depth, "");
1086     inputs = rsize;
1087     break;
1088 
1089   case Bytecodes::_jsr:
1090   case Bytecodes::_jsr_w:
1091     inputs = 0;
1092     depth  = 1;                  // S.B. depth=1, not zero
1093     break;
1094 
1095   default:
1096     // bytecode produces a typed result
1097     inputs = rsize - depth;
1098     assert(inputs >= 0, "");
1099     break;
1100   }
1101 
1102 #ifdef ASSERT
1103   // spot check
1104   int outputs = depth + inputs;
1105   assert(outputs >= 0, "sanity");
1106   switch (code) {
1107   case Bytecodes::_checkcast: assert(inputs == 1 && outputs == 1, ""); break;
1108   case Bytecodes::_athrow:    assert(inputs == 1 && outputs == 0, ""); break;
1109   case Bytecodes::_aload_0:   assert(inputs == 0 && outputs == 1, ""); break;
1110   case Bytecodes::_return:    assert(inputs == 0 && outputs == 0, ""); break;
1111   case Bytecodes::_drem:      assert(inputs == 4 && outputs == 2, ""); break;
1112   default:                    break;
1113   }
1114 #endif //ASSERT
1115 
1116   return true;
1117 }
1118 
1119 
1120 
1121 //------------------------------basic_plus_adr---------------------------------
1122 Node* GraphKit::basic_plus_adr(Node* base, Node* ptr, Node* offset) {
1123   // short-circuit a common case
1124   if (offset == intcon(0))  return ptr;
1125   return _gvn.transform( new AddPNode(base, ptr, offset) );
1126 }
1127 
1128 Node* GraphKit::ConvI2L(Node* offset) {
1129   // short-circuit a common case
1130   jint offset_con = find_int_con(offset, Type::OffsetBot);
1131   if (offset_con != Type::OffsetBot) {
1132     return longcon((jlong) offset_con);
1133   }
1134   return _gvn.transform( new ConvI2LNode(offset));
1135 }
1136 
1137 Node* GraphKit::ConvI2UL(Node* offset) {
1138   juint offset_con = (juint) find_int_con(offset, Type::OffsetBot);
1139   if (offset_con != (juint) Type::OffsetBot) {
1140     return longcon((julong) offset_con);
1141   }
1142   Node* conv = _gvn.transform( new ConvI2LNode(offset));
1143   Node* mask = _gvn.transform(ConLNode::make((julong) max_juint));
1144   return _gvn.transform( new AndLNode(conv, mask) );
1145 }
1146 
1147 Node* GraphKit::ConvL2I(Node* offset) {
1148   // short-circuit a common case
1149   jlong offset_con = find_long_con(offset, (jlong)Type::OffsetBot);
1150   if (offset_con != (jlong)Type::OffsetBot) {
1151     return intcon((int) offset_con);
1152   }
1153   return _gvn.transform( new ConvL2INode(offset));
1154 }
1155 
1156 //-------------------------load_object_klass-----------------------------------
1157 Node* GraphKit::load_object_klass(Node* obj) {
1158   // Special-case a fresh allocation to avoid building nodes:
1159   Node* akls = AllocateNode::Ideal_klass(obj, &_gvn);
1160   if (akls != NULL)  return akls;
1161   Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes());
1162   return _gvn.transform(LoadKlassNode::make(_gvn, NULL, immutable_memory(), k_adr, TypeInstPtr::KLASS));
1163 }
1164 
1165 //-------------------------load_array_length-----------------------------------
1166 Node* GraphKit::load_array_length(Node* array) {
1167   // Special-case a fresh allocation to avoid building nodes:
1168   AllocateArrayNode* alloc = AllocateArrayNode::Ideal_array_allocation(array, &_gvn);
1169   Node *alen;
1170   if (alloc == NULL) {
1171     Node *r_adr = basic_plus_adr(array, arrayOopDesc::length_offset_in_bytes());
1172     alen = _gvn.transform( new LoadRangeNode(0, immutable_memory(), r_adr, TypeInt::POS));
1173   } else {
1174     alen = alloc->Ideal_length();
1175     Node* ccast = alloc->make_ideal_length(_gvn.type(array)->is_oopptr(), &_gvn);
1176     if (ccast != alen) {
1177       alen = _gvn.transform(ccast);
1178     }
1179   }
1180   return alen;
1181 }
1182 
1183 //------------------------------do_null_check----------------------------------
1184 // Helper function to do a NULL pointer check.  Returned value is
1185 // the incoming address with NULL casted away.  You are allowed to use the
1186 // not-null value only if you are control dependent on the test.
1187 #ifndef PRODUCT
1188 extern int explicit_null_checks_inserted,
1189            explicit_null_checks_elided;
1190 #endif
1191 Node* GraphKit::null_check_common(Node* value, BasicType type,
1192                                   // optional arguments for variations:
1193                                   bool assert_null,
1194                                   Node* *null_control,
1195                                   bool speculative) {
1196   assert(!assert_null || null_control == NULL, "not both at once");
1197   if (stopped())  return top();
1198   NOT_PRODUCT(explicit_null_checks_inserted++);
1199 
1200   // Construct NULL check
1201   Node *chk = NULL;
1202   switch(type) {
1203     case T_LONG   : chk = new CmpLNode(value, _gvn.zerocon(T_LONG)); break;
1204     case T_INT    : chk = new CmpINode(value, _gvn.intcon(0)); break;
1205     case T_ARRAY  : // fall through
1206       type = T_OBJECT;  // simplify further tests
1207     case T_OBJECT : {
1208       const Type *t = _gvn.type( value );
1209 
1210       const TypeOopPtr* tp = t->isa_oopptr();
1211       if (tp != NULL && tp->klass() != NULL && !tp->klass()->is_loaded()
1212           // Only for do_null_check, not any of its siblings:
1213           && !assert_null && null_control == NULL) {
1214         // Usually, any field access or invocation on an unloaded oop type
1215         // will simply fail to link, since the statically linked class is
1216         // likely also to be unloaded.  However, in -Xcomp mode, sometimes
1217         // the static class is loaded but the sharper oop type is not.
1218         // Rather than checking for this obscure case in lots of places,
1219         // we simply observe that a null check on an unloaded class
1220         // will always be followed by a nonsense operation, so we
1221         // can just issue the uncommon trap here.
1222         // Our access to the unloaded class will only be correct
1223         // after it has been loaded and initialized, which requires
1224         // a trip through the interpreter.
1225 #ifndef PRODUCT
1226         if (WizardMode) { tty->print("Null check of unloaded "); tp->klass()->print(); tty->cr(); }
1227 #endif
1228         uncommon_trap(Deoptimization::Reason_unloaded,
1229                       Deoptimization::Action_reinterpret,
1230                       tp->klass(), "!loaded");
1231         return top();
1232       }
1233 
1234       if (assert_null) {
1235         // See if the type is contained in NULL_PTR.
1236         // If so, then the value is already null.
1237         if (t->higher_equal(TypePtr::NULL_PTR)) {
1238           NOT_PRODUCT(explicit_null_checks_elided++);
1239           return value;           // Elided null assert quickly!
1240         }
1241       } else {
1242         // See if mixing in the NULL pointer changes type.
1243         // If so, then the NULL pointer was not allowed in the original
1244         // type.  In other words, "value" was not-null.
1245         if (t->meet(TypePtr::NULL_PTR) != t->remove_speculative()) {
1246           // same as: if (!TypePtr::NULL_PTR->higher_equal(t)) ...
1247           NOT_PRODUCT(explicit_null_checks_elided++);
1248           return value;           // Elided null check quickly!
1249         }
1250       }
1251       chk = new CmpPNode( value, null() );
1252       break;
1253     }
1254 
1255     default:
1256       fatal("unexpected type: %s", type2name(type));
1257   }
1258   assert(chk != NULL, "sanity check");
1259   chk = _gvn.transform(chk);
1260 
1261   BoolTest::mask btest = assert_null ? BoolTest::eq : BoolTest::ne;
1262   BoolNode *btst = new BoolNode( chk, btest);
1263   Node   *tst = _gvn.transform( btst );
1264 
1265   //-----------
1266   // if peephole optimizations occurred, a prior test existed.
1267   // If a prior test existed, maybe it dominates as we can avoid this test.
1268   if (tst != btst && type == T_OBJECT) {
1269     // At this point we want to scan up the CFG to see if we can
1270     // find an identical test (and so avoid this test altogether).
1271     Node *cfg = control();
1272     int depth = 0;
1273     while( depth < 16 ) {       // Limit search depth for speed
1274       if( cfg->Opcode() == Op_IfTrue &&
1275           cfg->in(0)->in(1) == tst ) {
1276         // Found prior test.  Use "cast_not_null" to construct an identical
1277         // CastPP (and hence hash to) as already exists for the prior test.
1278         // Return that casted value.
1279         if (assert_null) {
1280           replace_in_map(value, null());
1281           return null();  // do not issue the redundant test
1282         }
1283         Node *oldcontrol = control();
1284         set_control(cfg);
1285         Node *res = cast_not_null(value);
1286         set_control(oldcontrol);
1287         NOT_PRODUCT(explicit_null_checks_elided++);
1288         return res;
1289       }
1290       cfg = IfNode::up_one_dom(cfg, /*linear_only=*/ true);
1291       if (cfg == NULL)  break;  // Quit at region nodes
1292       depth++;
1293     }
1294   }
1295 
1296   //-----------
1297   // Branch to failure if null
1298   float ok_prob = PROB_MAX;  // a priori estimate:  nulls never happen
1299   Deoptimization::DeoptReason reason;
1300   if (assert_null) {
1301     reason = Deoptimization::reason_null_assert(speculative);
1302   } else if (type == T_OBJECT) {
1303     reason = Deoptimization::reason_null_check(speculative);
1304   } else {
1305     reason = Deoptimization::Reason_div0_check;
1306   }
1307   // %%% Since Reason_unhandled is not recorded on a per-bytecode basis,
1308   // ciMethodData::has_trap_at will return a conservative -1 if any
1309   // must-be-null assertion has failed.  This could cause performance
1310   // problems for a method after its first do_null_assert failure.
1311   // Consider using 'Reason_class_check' instead?
1312 
1313   // To cause an implicit null check, we set the not-null probability
1314   // to the maximum (PROB_MAX).  For an explicit check the probability
1315   // is set to a smaller value.
1316   if (null_control != NULL || too_many_traps(reason)) {
1317     // probability is less likely
1318     ok_prob =  PROB_LIKELY_MAG(3);
1319   } else if (!assert_null &&
1320              (ImplicitNullCheckThreshold > 0) &&
1321              method() != NULL &&
1322              (method()->method_data()->trap_count(reason)
1323               >= (uint)ImplicitNullCheckThreshold)) {
1324     ok_prob =  PROB_LIKELY_MAG(3);
1325   }
1326 
1327   if (null_control != NULL) {
1328     IfNode* iff = create_and_map_if(control(), tst, ok_prob, COUNT_UNKNOWN);
1329     Node* null_true = _gvn.transform( new IfFalseNode(iff));
1330     set_control(      _gvn.transform( new IfTrueNode(iff)));
1331 #ifndef PRODUCT
1332     if (null_true == top()) {
1333       explicit_null_checks_elided++;
1334     }
1335 #endif
1336     (*null_control) = null_true;
1337   } else {
1338     BuildCutout unless(this, tst, ok_prob);
1339     // Check for optimizer eliding test at parse time
1340     if (stopped()) {
1341       // Failure not possible; do not bother making uncommon trap.
1342       NOT_PRODUCT(explicit_null_checks_elided++);
1343     } else if (assert_null) {
1344       uncommon_trap(reason,
1345                     Deoptimization::Action_make_not_entrant,
1346                     NULL, "assert_null");
1347     } else {
1348       replace_in_map(value, zerocon(type));
1349       builtin_throw(reason);
1350     }
1351   }
1352 
1353   // Must throw exception, fall-thru not possible?
1354   if (stopped()) {
1355     return top();               // No result
1356   }
1357 
1358   if (assert_null) {
1359     // Cast obj to null on this path.
1360     replace_in_map(value, zerocon(type));
1361     return zerocon(type);
1362   }
1363 
1364   // Cast obj to not-null on this path, if there is no null_control.
1365   // (If there is a null_control, a non-null value may come back to haunt us.)
1366   if (type == T_OBJECT) {
1367     Node* cast = cast_not_null(value, false);
1368     if (null_control == NULL || (*null_control) == top())
1369       replace_in_map(value, cast);
1370     value = cast;
1371   }
1372 
1373   return value;
1374 }
1375 
1376 
1377 //------------------------------cast_not_null----------------------------------
1378 // Cast obj to not-null on this path
1379 Node* GraphKit::cast_not_null(Node* obj, bool do_replace_in_map) {
1380   const Type *t = _gvn.type(obj);
1381   const Type *t_not_null = t->join_speculative(TypePtr::NOTNULL);
1382   // Object is already not-null?
1383   if( t == t_not_null ) return obj;
1384 
1385   Node *cast = new CastPPNode(obj,t_not_null);
1386   cast->init_req(0, control());
1387   cast = _gvn.transform( cast );
1388 
1389   // Scan for instances of 'obj' in the current JVM mapping.
1390   // These instances are known to be not-null after the test.
1391   if (do_replace_in_map)
1392     replace_in_map(obj, cast);
1393 
1394   return cast;                  // Return casted value
1395 }
1396 
1397 // Sometimes in intrinsics, we implicitly know an object is not null
1398 // (there's no actual null check) so we can cast it to not null. In
1399 // the course of optimizations, the input to the cast can become null.
1400 // In that case that data path will die and we need the control path
1401 // to become dead as well to keep the graph consistent. So we have to
1402 // add a check for null for which one branch can't be taken. It uses
1403 // an Opaque4 node that will cause the check to be removed after loop
1404 // opts so the test goes away and the compiled code doesn't execute a
1405 // useless check.
1406 Node* GraphKit::must_be_not_null(Node* value, bool do_replace_in_map) {
1407   Node* chk = _gvn.transform(new CmpPNode(value, null()));
1408   Node *tst = _gvn.transform(new BoolNode(chk, BoolTest::ne));
1409   Node* opaq = _gvn.transform(new Opaque4Node(C, tst, intcon(1)));
1410   IfNode *iff = new IfNode(control(), opaq, PROB_MAX, COUNT_UNKNOWN);
1411   _gvn.set_type(iff, iff->Value(&_gvn));
1412   Node *if_f = _gvn.transform(new IfFalseNode(iff));
1413   Node *frame = _gvn.transform(new ParmNode(C->start(), TypeFunc::FramePtr));
1414   Node *halt = _gvn.transform(new HaltNode(if_f, frame));
1415   C->root()->add_req(halt);
1416   Node *if_t = _gvn.transform(new IfTrueNode(iff));
1417   set_control(if_t);
1418   return cast_not_null(value, do_replace_in_map);
1419 }
1420 
1421 
1422 //--------------------------replace_in_map-------------------------------------
1423 void GraphKit::replace_in_map(Node* old, Node* neww) {
1424   if (old == neww) {
1425     return;
1426   }
1427 
1428   map()->replace_edge(old, neww);
1429 
1430   // Note: This operation potentially replaces any edge
1431   // on the map.  This includes locals, stack, and monitors
1432   // of the current (innermost) JVM state.
1433 
1434   // don't let inconsistent types from profiling escape this
1435   // method
1436 
1437   const Type* told = _gvn.type(old);
1438   const Type* tnew = _gvn.type(neww);
1439 
1440   if (!tnew->higher_equal(told)) {
1441     return;
1442   }
1443 
1444   map()->record_replaced_node(old, neww);
1445 }
1446 
1447 
1448 //=============================================================================
1449 //--------------------------------memory---------------------------------------
1450 Node* GraphKit::memory(uint alias_idx) {
1451   MergeMemNode* mem = merged_memory();
1452   Node* p = mem->memory_at(alias_idx);
1453   _gvn.set_type(p, Type::MEMORY);  // must be mapped
1454   return p;
1455 }
1456 
1457 //-----------------------------reset_memory------------------------------------
1458 Node* GraphKit::reset_memory() {
1459   Node* mem = map()->memory();
1460   // do not use this node for any more parsing!
1461   debug_only( map()->set_memory((Node*)NULL) );
1462   return _gvn.transform( mem );
1463 }
1464 
1465 //------------------------------set_all_memory---------------------------------
1466 void GraphKit::set_all_memory(Node* newmem) {
1467   Node* mergemem = MergeMemNode::make(newmem);
1468   gvn().set_type_bottom(mergemem);
1469   map()->set_memory(mergemem);
1470 }
1471 
1472 //------------------------------set_all_memory_call----------------------------
1473 void GraphKit::set_all_memory_call(Node* call, bool separate_io_proj) {
1474   Node* newmem = _gvn.transform( new ProjNode(call, TypeFunc::Memory, separate_io_proj) );
1475   set_all_memory(newmem);
1476 }
1477 
1478 //=============================================================================
1479 //
1480 // parser factory methods for MemNodes
1481 //
1482 // These are layered on top of the factory methods in LoadNode and StoreNode,
1483 // and integrate with the parser's memory state and _gvn engine.
1484 //
1485 
1486 // factory methods in "int adr_idx"
1487 Node* GraphKit::make_load(Node* ctl, Node* adr, const Type* t, BasicType bt,
1488                           int adr_idx,
1489                           MemNode::MemOrd mo,
1490                           LoadNode::ControlDependency control_dependency,
1491                           bool require_atomic_access,
1492                           bool unaligned,
1493                           bool mismatched) {
1494   assert(adr_idx != Compile::AliasIdxTop, "use other make_load factory" );
1495   const TypePtr* adr_type = NULL; // debug-mode-only argument
1496   debug_only(adr_type = C->get_adr_type(adr_idx));
1497   Node* mem = memory(adr_idx);
1498   Node* ld;
1499   if (require_atomic_access && bt == T_LONG) {
1500     ld = LoadLNode::make_atomic(ctl, mem, adr, adr_type, t, mo, control_dependency, unaligned, mismatched);
1501   } else if (require_atomic_access && bt == T_DOUBLE) {
1502     ld = LoadDNode::make_atomic(ctl, mem, adr, adr_type, t, mo, control_dependency, unaligned, mismatched);
1503   } else {
1504     ld = LoadNode::make(_gvn, ctl, mem, adr, adr_type, t, bt, mo, control_dependency, unaligned, mismatched);
1505   }
1506   ld = _gvn.transform(ld);
1507   if (((bt == T_OBJECT) && C->do_escape_analysis()) || C->eliminate_boxing()) {
1508     // Improve graph before escape analysis and boxing elimination.
1509     record_for_igvn(ld);
1510   }
1511   return ld;
1512 }
1513 
1514 Node* GraphKit::store_to_memory(Node* ctl, Node* adr, Node *val, BasicType bt,
1515                                 int adr_idx,
1516                                 MemNode::MemOrd mo,
1517                                 bool require_atomic_access,
1518                                 bool unaligned,
1519                                 bool mismatched) {
1520   assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
1521   const TypePtr* adr_type = NULL;
1522   debug_only(adr_type = C->get_adr_type(adr_idx));
1523   Node *mem = memory(adr_idx);
1524   Node* st;
1525   if (require_atomic_access && bt == T_LONG) {
1526     st = StoreLNode::make_atomic(ctl, mem, adr, adr_type, val, mo);
1527   } else if (require_atomic_access && bt == T_DOUBLE) {
1528     st = StoreDNode::make_atomic(ctl, mem, adr, adr_type, val, mo);
1529   } else {
1530     st = StoreNode::make(_gvn, ctl, mem, adr, adr_type, val, bt, mo);
1531   }
1532   if (unaligned) {
1533     st->as_Store()->set_unaligned_access();
1534   }
1535   if (mismatched) {
1536     st->as_Store()->set_mismatched_access();
1537   }
1538   st = _gvn.transform(st);
1539   set_memory(st, adr_idx);
1540   // Back-to-back stores can only remove intermediate store with DU info
1541   // so push on worklist for optimizer.
1542   if (mem->req() > MemNode::Address && adr == mem->in(MemNode::Address))
1543     record_for_igvn(st);
1544 
1545   return st;
1546 }
1547 
1548 
1549 void GraphKit::pre_barrier(bool do_load,
1550                            Node* ctl,
1551                            Node* obj,
1552                            Node* adr,
1553                            uint  adr_idx,
1554                            Node* val,
1555                            const TypeOopPtr* val_type,
1556                            Node* pre_val,
1557                            BasicType bt) {
1558 
1559   BarrierSet* bs = Universe::heap()->barrier_set();
1560   set_control(ctl);
1561   switch (bs->kind()) {
1562     case BarrierSet::G1SATBCTLogging:
1563       g1_write_barrier_pre(do_load, obj, adr, adr_idx, val, val_type, pre_val, bt);
1564       break;
1565 
1566     case BarrierSet::CardTableForRS:
1567     case BarrierSet::CardTableExtension:
1568     case BarrierSet::ModRef:
1569       break;
1570 
1571     default      :
1572       ShouldNotReachHere();
1573 
1574   }
1575 }
1576 
1577 bool GraphKit::can_move_pre_barrier() const {
1578   BarrierSet* bs = Universe::heap()->barrier_set();
1579   switch (bs->kind()) {
1580     case BarrierSet::G1SATBCTLogging:
1581       return true; // Can move it if no safepoint
1582 
1583     case BarrierSet::CardTableForRS:
1584     case BarrierSet::CardTableExtension:
1585     case BarrierSet::ModRef:
1586       return true; // There is no pre-barrier
1587 
1588     default      :
1589       ShouldNotReachHere();
1590   }
1591   return false;
1592 }
1593 
1594 void GraphKit::post_barrier(Node* ctl,
1595                             Node* store,
1596                             Node* obj,
1597                             Node* adr,
1598                             uint  adr_idx,
1599                             Node* val,
1600                             BasicType bt,
1601                             bool use_precise) {
1602   BarrierSet* bs = Universe::heap()->barrier_set();
1603   set_control(ctl);
1604   switch (bs->kind()) {
1605     case BarrierSet::G1SATBCTLogging:
1606       g1_write_barrier_post(store, obj, adr, adr_idx, val, bt, use_precise);
1607       break;
1608 
1609     case BarrierSet::CardTableForRS:
1610     case BarrierSet::CardTableExtension:
1611       write_barrier_post(store, obj, adr, adr_idx, val, use_precise);
1612       break;
1613 
1614     case BarrierSet::ModRef:
1615       break;
1616 
1617     default      :
1618       ShouldNotReachHere();
1619 
1620   }
1621 }
1622 
1623 Node* GraphKit::store_oop(Node* ctl,
1624                           Node* obj,
1625                           Node* adr,
1626                           const TypePtr* adr_type,
1627                           Node* val,
1628                           const TypeOopPtr* val_type,
1629                           BasicType bt,
1630                           bool use_precise,
1631                           MemNode::MemOrd mo,
1632                           bool mismatched) {
1633   // Transformation of a value which could be NULL pointer (CastPP #NULL)
1634   // could be delayed during Parse (for example, in adjust_map_after_if()).
1635   // Execute transformation here to avoid barrier generation in such case.
1636   if (_gvn.type(val) == TypePtr::NULL_PTR)
1637     val = _gvn.makecon(TypePtr::NULL_PTR);
1638 
1639   set_control(ctl);
1640   if (stopped()) return top(); // Dead path ?
1641 
1642   assert(bt == T_OBJECT, "sanity");
1643   assert(val != NULL, "not dead path");
1644   uint adr_idx = C->get_alias_index(adr_type);
1645   assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
1646 
1647   pre_barrier(true /* do_load */,
1648               control(), obj, adr, adr_idx, val, val_type,
1649               NULL /* pre_val */,
1650               bt);
1651 
1652   Node* store = store_to_memory(control(), adr, val, bt, adr_idx, mo, mismatched);
1653   post_barrier(control(), store, obj, adr, adr_idx, val, bt, use_precise);
1654   return store;
1655 }
1656 
1657 // Could be an array or object we don't know at compile time (unsafe ref.)
1658 Node* GraphKit::store_oop_to_unknown(Node* ctl,
1659                              Node* obj,   // containing obj
1660                              Node* adr,  // actual adress to store val at
1661                              const TypePtr* adr_type,
1662                              Node* val,
1663                              BasicType bt,
1664                              MemNode::MemOrd mo,
1665                              bool mismatched) {
1666   Compile::AliasType* at = C->alias_type(adr_type);
1667   const TypeOopPtr* val_type = NULL;
1668   if (adr_type->isa_instptr()) {
1669     if (at->field() != NULL) {
1670       // known field.  This code is a copy of the do_put_xxx logic.
1671       ciField* field = at->field();
1672       if (!field->type()->is_loaded()) {
1673         val_type = TypeInstPtr::BOTTOM;
1674       } else {
1675         val_type = TypeOopPtr::make_from_klass(field->type()->as_klass());
1676       }
1677     }
1678   } else if (adr_type->isa_aryptr()) {
1679     val_type = adr_type->is_aryptr()->elem()->make_oopptr();
1680   }
1681   if (val_type == NULL) {
1682     val_type = TypeInstPtr::BOTTOM;
1683   }
1684   return store_oop(ctl, obj, adr, adr_type, val, val_type, bt, true, mo, mismatched);
1685 }
1686 
1687 
1688 //-------------------------array_element_address-------------------------
1689 Node* GraphKit::array_element_address(Node* ary, Node* idx, BasicType elembt,
1690                                       const TypeInt* sizetype, Node* ctrl) {
1691   uint shift  = exact_log2(type2aelembytes(elembt));
1692   uint header = arrayOopDesc::base_offset_in_bytes(elembt);
1693 
1694   // short-circuit a common case (saves lots of confusing waste motion)
1695   jint idx_con = find_int_con(idx, -1);
1696   if (idx_con >= 0) {
1697     intptr_t offset = header + ((intptr_t)idx_con << shift);
1698     return basic_plus_adr(ary, offset);
1699   }
1700 
1701   // must be correct type for alignment purposes
1702   Node* base  = basic_plus_adr(ary, header);
1703   idx = Compile::conv_I2X_index(&_gvn, idx, sizetype, ctrl);
1704   Node* scale = _gvn.transform( new LShiftXNode(idx, intcon(shift)) );
1705   return basic_plus_adr(ary, base, scale);
1706 }
1707 
1708 //-------------------------load_array_element-------------------------
1709 Node* GraphKit::load_array_element(Node* ctl, Node* ary, Node* idx, const TypeAryPtr* arytype) {
1710   const Type* elemtype = arytype->elem();
1711   BasicType elembt = elemtype->array_element_basic_type();
1712   Node* adr = array_element_address(ary, idx, elembt, arytype->size());
1713   if (elembt == T_NARROWOOP) {
1714     elembt = T_OBJECT; // To satisfy switch in LoadNode::make()
1715   }
1716   Node* ld = make_load(ctl, adr, elemtype, elembt, arytype, MemNode::unordered);
1717   return ld;
1718 }
1719 
1720 //-------------------------set_arguments_for_java_call-------------------------
1721 // Arguments (pre-popped from the stack) are taken from the JVMS.
1722 void GraphKit::set_arguments_for_java_call(CallJavaNode* call) {
1723   // Add the call arguments:
1724   uint nargs = call->method()->arg_size();
1725   for (uint i = 0; i < nargs; i++) {
1726     Node* arg = argument(i);
1727     call->init_req(i + TypeFunc::Parms, arg);
1728   }
1729 }
1730 
1731 //---------------------------set_edges_for_java_call---------------------------
1732 // Connect a newly created call into the current JVMS.
1733 // A return value node (if any) is returned from set_edges_for_java_call.
1734 void GraphKit::set_edges_for_java_call(CallJavaNode* call, bool must_throw, bool separate_io_proj) {
1735 
1736   // Add the predefined inputs:
1737   call->init_req( TypeFunc::Control, control() );
1738   call->init_req( TypeFunc::I_O    , i_o() );
1739   call->init_req( TypeFunc::Memory , reset_memory() );
1740   call->init_req( TypeFunc::FramePtr, frameptr() );
1741   call->init_req( TypeFunc::ReturnAdr, top() );
1742 
1743   add_safepoint_edges(call, must_throw);
1744 
1745   Node* xcall = _gvn.transform(call);
1746 
1747   if (xcall == top()) {
1748     set_control(top());
1749     return;
1750   }
1751   assert(xcall == call, "call identity is stable");
1752 
1753   // Re-use the current map to produce the result.
1754 
1755   set_control(_gvn.transform(new ProjNode(call, TypeFunc::Control)));
1756   set_i_o(    _gvn.transform(new ProjNode(call, TypeFunc::I_O    , separate_io_proj)));
1757   set_all_memory_call(xcall, separate_io_proj);
1758 
1759   //return xcall;   // no need, caller already has it
1760 }
1761 
1762 Node* GraphKit::set_results_for_java_call(CallJavaNode* call, bool separate_io_proj) {
1763   if (stopped())  return top();  // maybe the call folded up?
1764 
1765   // Capture the return value, if any.
1766   Node* ret;
1767   if (call->method() == NULL ||
1768       call->method()->return_type()->basic_type() == T_VOID)
1769         ret = top();
1770   else  ret = _gvn.transform(new ProjNode(call, TypeFunc::Parms));
1771 
1772   // Note:  Since any out-of-line call can produce an exception,
1773   // we always insert an I_O projection from the call into the result.
1774 
1775   make_slow_call_ex(call, env()->Throwable_klass(), separate_io_proj);
1776 
1777   if (separate_io_proj) {
1778     // The caller requested separate projections be used by the fall
1779     // through and exceptional paths, so replace the projections for
1780     // the fall through path.
1781     set_i_o(_gvn.transform( new ProjNode(call, TypeFunc::I_O) ));
1782     set_all_memory(_gvn.transform( new ProjNode(call, TypeFunc::Memory) ));
1783   }
1784   return ret;
1785 }
1786 
1787 //--------------------set_predefined_input_for_runtime_call--------------------
1788 // Reading and setting the memory state is way conservative here.
1789 // The real problem is that I am not doing real Type analysis on memory,
1790 // so I cannot distinguish card mark stores from other stores.  Across a GC
1791 // point the Store Barrier and the card mark memory has to agree.  I cannot
1792 // have a card mark store and its barrier split across the GC point from
1793 // either above or below.  Here I get that to happen by reading ALL of memory.
1794 // A better answer would be to separate out card marks from other memory.
1795 // For now, return the input memory state, so that it can be reused
1796 // after the call, if this call has restricted memory effects.
1797 Node* GraphKit::set_predefined_input_for_runtime_call(SafePointNode* call) {
1798   // Set fixed predefined input arguments
1799   Node* memory = reset_memory();
1800   call->init_req( TypeFunc::Control,   control()  );
1801   call->init_req( TypeFunc::I_O,       top()      ); // does no i/o
1802   call->init_req( TypeFunc::Memory,    memory     ); // may gc ptrs
1803   call->init_req( TypeFunc::FramePtr,  frameptr() );
1804   call->init_req( TypeFunc::ReturnAdr, top()      );
1805   return memory;
1806 }
1807 
1808 //-------------------set_predefined_output_for_runtime_call--------------------
1809 // Set control and memory (not i_o) from the call.
1810 // If keep_mem is not NULL, use it for the output state,
1811 // except for the RawPtr output of the call, if hook_mem is TypeRawPtr::BOTTOM.
1812 // If hook_mem is NULL, this call produces no memory effects at all.
1813 // If hook_mem is a Java-visible memory slice (such as arraycopy operands),
1814 // then only that memory slice is taken from the call.
1815 // In the last case, we must put an appropriate memory barrier before
1816 // the call, so as to create the correct anti-dependencies on loads
1817 // preceding the call.
1818 void GraphKit::set_predefined_output_for_runtime_call(Node* call,
1819                                                       Node* keep_mem,
1820                                                       const TypePtr* hook_mem) {
1821   // no i/o
1822   set_control(_gvn.transform( new ProjNode(call,TypeFunc::Control) ));
1823   if (keep_mem) {
1824     // First clone the existing memory state
1825     set_all_memory(keep_mem);
1826     if (hook_mem != NULL) {
1827       // Make memory for the call
1828       Node* mem = _gvn.transform( new ProjNode(call, TypeFunc::Memory) );
1829       // Set the RawPtr memory state only.  This covers all the heap top/GC stuff
1830       // We also use hook_mem to extract specific effects from arraycopy stubs.
1831       set_memory(mem, hook_mem);
1832     }
1833     // ...else the call has NO memory effects.
1834 
1835     // Make sure the call advertises its memory effects precisely.
1836     // This lets us build accurate anti-dependences in gcm.cpp.
1837     assert(C->alias_type(call->adr_type()) == C->alias_type(hook_mem),
1838            "call node must be constructed correctly");
1839   } else {
1840     assert(hook_mem == NULL, "");
1841     // This is not a "slow path" call; all memory comes from the call.
1842     set_all_memory_call(call);
1843   }
1844 }
1845 
1846 
1847 // Replace the call with the current state of the kit.
1848 void GraphKit::replace_call(CallNode* call, Node* result, bool do_replaced_nodes) {
1849   JVMState* ejvms = NULL;
1850   if (has_exceptions()) {
1851     ejvms = transfer_exceptions_into_jvms();
1852   }
1853 
1854   ReplacedNodes replaced_nodes = map()->replaced_nodes();
1855   ReplacedNodes replaced_nodes_exception;
1856   Node* ex_ctl = top();
1857 
1858   SafePointNode* final_state = stop();
1859 
1860   // Find all the needed outputs of this call
1861   CallProjections callprojs;
1862   call->extract_projections(&callprojs, true);
1863 
1864   Node* init_mem = call->in(TypeFunc::Memory);
1865   Node* final_mem = final_state->in(TypeFunc::Memory);
1866   Node* final_ctl = final_state->in(TypeFunc::Control);
1867   Node* final_io = final_state->in(TypeFunc::I_O);
1868 
1869   // Replace all the old call edges with the edges from the inlining result
1870   if (callprojs.fallthrough_catchproj != NULL) {
1871     C->gvn_replace_by(callprojs.fallthrough_catchproj, final_ctl);
1872   }
1873   if (callprojs.fallthrough_memproj != NULL) {
1874     if (final_mem->is_MergeMem()) {
1875       // Parser's exits MergeMem was not transformed but may be optimized
1876       final_mem = _gvn.transform(final_mem);
1877     }
1878     C->gvn_replace_by(callprojs.fallthrough_memproj,   final_mem);
1879   }
1880   if (callprojs.fallthrough_ioproj != NULL) {
1881     C->gvn_replace_by(callprojs.fallthrough_ioproj,    final_io);
1882   }
1883 
1884   // Replace the result with the new result if it exists and is used
1885   if (callprojs.resproj != NULL && result != NULL) {
1886     C->gvn_replace_by(callprojs.resproj, result);
1887   }
1888 
1889   if (ejvms == NULL) {
1890     // No exception edges to simply kill off those paths
1891     if (callprojs.catchall_catchproj != NULL) {
1892       C->gvn_replace_by(callprojs.catchall_catchproj, C->top());
1893     }
1894     if (callprojs.catchall_memproj != NULL) {
1895       C->gvn_replace_by(callprojs.catchall_memproj,   C->top());
1896     }
1897     if (callprojs.catchall_ioproj != NULL) {
1898       C->gvn_replace_by(callprojs.catchall_ioproj,    C->top());
1899     }
1900     // Replace the old exception object with top
1901     if (callprojs.exobj != NULL) {
1902       C->gvn_replace_by(callprojs.exobj, C->top());
1903     }
1904   } else {
1905     GraphKit ekit(ejvms);
1906 
1907     // Load my combined exception state into the kit, with all phis transformed:
1908     SafePointNode* ex_map = ekit.combine_and_pop_all_exception_states();
1909     replaced_nodes_exception = ex_map->replaced_nodes();
1910 
1911     Node* ex_oop = ekit.use_exception_state(ex_map);
1912 
1913     if (callprojs.catchall_catchproj != NULL) {
1914       C->gvn_replace_by(callprojs.catchall_catchproj, ekit.control());
1915       ex_ctl = ekit.control();
1916     }
1917     if (callprojs.catchall_memproj != NULL) {
1918       C->gvn_replace_by(callprojs.catchall_memproj,   ekit.reset_memory());
1919     }
1920     if (callprojs.catchall_ioproj != NULL) {
1921       C->gvn_replace_by(callprojs.catchall_ioproj,    ekit.i_o());
1922     }
1923 
1924     // Replace the old exception object with the newly created one
1925     if (callprojs.exobj != NULL) {
1926       C->gvn_replace_by(callprojs.exobj, ex_oop);
1927     }
1928   }
1929 
1930   // Disconnect the call from the graph
1931   call->disconnect_inputs(NULL, C);
1932   C->gvn_replace_by(call, C->top());
1933 
1934   // Clean up any MergeMems that feed other MergeMems since the
1935   // optimizer doesn't like that.
1936   if (final_mem->is_MergeMem()) {
1937     Node_List wl;
1938     for (SimpleDUIterator i(final_mem); i.has_next(); i.next()) {
1939       Node* m = i.get();
1940       if (m->is_MergeMem() && !wl.contains(m)) {
1941         wl.push(m);
1942       }
1943     }
1944     while (wl.size()  > 0) {
1945       _gvn.transform(wl.pop());
1946     }
1947   }
1948 
1949   if (callprojs.fallthrough_catchproj != NULL && !final_ctl->is_top() && do_replaced_nodes) {
1950     replaced_nodes.apply(C, final_ctl);
1951   }
1952   if (!ex_ctl->is_top() && do_replaced_nodes) {
1953     replaced_nodes_exception.apply(C, ex_ctl);
1954   }
1955 }
1956 
1957 
1958 //------------------------------increment_counter------------------------------
1959 // for statistics: increment a VM counter by 1
1960 
1961 void GraphKit::increment_counter(address counter_addr) {
1962   Node* adr1 = makecon(TypeRawPtr::make(counter_addr));
1963   increment_counter(adr1);
1964 }
1965 
1966 void GraphKit::increment_counter(Node* counter_addr) {
1967   int adr_type = Compile::AliasIdxRaw;
1968   Node* ctrl = control();
1969   Node* cnt  = make_load(ctrl, counter_addr, TypeInt::INT, T_INT, adr_type, MemNode::unordered);
1970   Node* incr = _gvn.transform(new AddINode(cnt, _gvn.intcon(1)));
1971   store_to_memory(ctrl, counter_addr, incr, T_INT, adr_type, MemNode::unordered);
1972 }
1973 
1974 
1975 //------------------------------uncommon_trap----------------------------------
1976 // Bail out to the interpreter in mid-method.  Implemented by calling the
1977 // uncommon_trap blob.  This helper function inserts a runtime call with the
1978 // right debug info.
1979 void GraphKit::uncommon_trap(int trap_request,
1980                              ciKlass* klass, const char* comment,
1981                              bool must_throw,
1982                              bool keep_exact_action) {
1983   if (failing())  stop();
1984   if (stopped())  return; // trap reachable?
1985 
1986   // Note:  If ProfileTraps is true, and if a deopt. actually
1987   // occurs here, the runtime will make sure an MDO exists.  There is
1988   // no need to call method()->ensure_method_data() at this point.
1989 
1990   // Set the stack pointer to the right value for reexecution:
1991   set_sp(reexecute_sp());
1992 
1993 #ifdef ASSERT
1994   if (!must_throw) {
1995     // Make sure the stack has at least enough depth to execute
1996     // the current bytecode.
1997     int inputs, ignored_depth;
1998     if (compute_stack_effects(inputs, ignored_depth)) {
1999       assert(sp() >= inputs, "must have enough JVMS stack to execute %s: sp=%d, inputs=%d",
2000              Bytecodes::name(java_bc()), sp(), inputs);
2001     }
2002   }
2003 #endif
2004 
2005   Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(trap_request);
2006   Deoptimization::DeoptAction action = Deoptimization::trap_request_action(trap_request);
2007 
2008   switch (action) {
2009   case Deoptimization::Action_maybe_recompile:
2010   case Deoptimization::Action_reinterpret:
2011     // Temporary fix for 6529811 to allow virtual calls to be sure they
2012     // get the chance to go from mono->bi->mega
2013     if (!keep_exact_action &&
2014         Deoptimization::trap_request_index(trap_request) < 0 &&
2015         too_many_recompiles(reason)) {
2016       // This BCI is causing too many recompilations.
2017       if (C->log() != NULL) {
2018         C->log()->elem("observe that='trap_action_change' reason='%s' from='%s' to='none'",
2019                 Deoptimization::trap_reason_name(reason),
2020                 Deoptimization::trap_action_name(action));
2021       }
2022       action = Deoptimization::Action_none;
2023       trap_request = Deoptimization::make_trap_request(reason, action);
2024     } else {
2025       C->set_trap_can_recompile(true);
2026     }
2027     break;
2028   case Deoptimization::Action_make_not_entrant:
2029     C->set_trap_can_recompile(true);
2030     break;
2031   case Deoptimization::Action_none:
2032   case Deoptimization::Action_make_not_compilable:
2033     break;
2034   default:
2035 #ifdef ASSERT
2036     fatal("unknown action %d: %s", action, Deoptimization::trap_action_name(action));
2037 #endif
2038     break;
2039   }
2040 
2041   if (TraceOptoParse) {
2042     char buf[100];
2043     tty->print_cr("Uncommon trap %s at bci:%d",
2044                   Deoptimization::format_trap_request(buf, sizeof(buf),
2045                                                       trap_request), bci());
2046   }
2047 
2048   CompileLog* log = C->log();
2049   if (log != NULL) {
2050     int kid = (klass == NULL)? -1: log->identify(klass);
2051     log->begin_elem("uncommon_trap bci='%d'", bci());
2052     char buf[100];
2053     log->print(" %s", Deoptimization::format_trap_request(buf, sizeof(buf),
2054                                                           trap_request));
2055     if (kid >= 0)         log->print(" klass='%d'", kid);
2056     if (comment != NULL)  log->print(" comment='%s'", comment);
2057     log->end_elem();
2058   }
2059 
2060   // Make sure any guarding test views this path as very unlikely
2061   Node *i0 = control()->in(0);
2062   if (i0 != NULL && i0->is_If()) {        // Found a guarding if test?
2063     IfNode *iff = i0->as_If();
2064     float f = iff->_prob;   // Get prob
2065     if (control()->Opcode() == Op_IfTrue) {
2066       if (f > PROB_UNLIKELY_MAG(4))
2067         iff->_prob = PROB_MIN;
2068     } else {
2069       if (f < PROB_LIKELY_MAG(4))
2070         iff->_prob = PROB_MAX;
2071     }
2072   }
2073 
2074   // Clear out dead values from the debug info.
2075   kill_dead_locals();
2076 
2077   // Now insert the uncommon trap subroutine call
2078   address call_addr = SharedRuntime::uncommon_trap_blob()->entry_point();
2079   const TypePtr* no_memory_effects = NULL;
2080   // Pass the index of the class to be loaded
2081   Node* call = make_runtime_call(RC_NO_LEAF | RC_UNCOMMON |
2082                                  (must_throw ? RC_MUST_THROW : 0),
2083                                  OptoRuntime::uncommon_trap_Type(),
2084                                  call_addr, "uncommon_trap", no_memory_effects,
2085                                  intcon(trap_request));
2086   assert(call->as_CallStaticJava()->uncommon_trap_request() == trap_request,
2087          "must extract request correctly from the graph");
2088   assert(trap_request != 0, "zero value reserved by uncommon_trap_request");
2089 
2090   call->set_req(TypeFunc::ReturnAdr, returnadr());
2091   // The debug info is the only real input to this call.
2092 
2093   // Halt-and-catch fire here.  The above call should never return!
2094   HaltNode* halt = new HaltNode(control(), frameptr());
2095   _gvn.set_type_bottom(halt);
2096   root()->add_req(halt);
2097 
2098   stop_and_kill_map();
2099 }
2100 
2101 
2102 //--------------------------just_allocated_object------------------------------
2103 // Report the object that was just allocated.
2104 // It must be the case that there are no intervening safepoints.
2105 // We use this to determine if an object is so "fresh" that
2106 // it does not require card marks.
2107 Node* GraphKit::just_allocated_object(Node* current_control) {
2108   if (C->recent_alloc_ctl() == current_control)
2109     return C->recent_alloc_obj();
2110   return NULL;
2111 }
2112 
2113 
2114 void GraphKit::round_double_arguments(ciMethod* dest_method) {
2115   // (Note:  TypeFunc::make has a cache that makes this fast.)
2116   const TypeFunc* tf    = TypeFunc::make(dest_method);
2117   int             nargs = tf->domain()->cnt() - TypeFunc::Parms;
2118   for (int j = 0; j < nargs; j++) {
2119     const Type *targ = tf->domain()->field_at(j + TypeFunc::Parms);
2120     if( targ->basic_type() == T_DOUBLE ) {
2121       // If any parameters are doubles, they must be rounded before
2122       // the call, dstore_rounding does gvn.transform
2123       Node *arg = argument(j);
2124       arg = dstore_rounding(arg);
2125       set_argument(j, arg);
2126     }
2127   }
2128 }
2129 
2130 /**
2131  * Record profiling data exact_kls for Node n with the type system so
2132  * that it can propagate it (speculation)
2133  *
2134  * @param n          node that the type applies to
2135  * @param exact_kls  type from profiling
2136  * @param maybe_null did profiling see null?
2137  *
2138  * @return           node with improved type
2139  */
2140 Node* GraphKit::record_profile_for_speculation(Node* n, ciKlass* exact_kls, ProfilePtrKind ptr_kind) {
2141   const Type* current_type = _gvn.type(n);
2142   assert(UseTypeSpeculation, "type speculation must be on");
2143 
2144   const TypePtr* speculative = current_type->speculative();
2145 
2146   // Should the klass from the profile be recorded in the speculative type?
2147   if (current_type->would_improve_type(exact_kls, jvms()->depth())) {
2148     const TypeKlassPtr* tklass = TypeKlassPtr::make(exact_kls);
2149     const TypeOopPtr* xtype = tklass->as_instance_type();
2150     assert(xtype->klass_is_exact(), "Should be exact");
2151     // Any reason to believe n is not null (from this profiling or a previous one)?
2152     assert(ptr_kind != ProfileAlwaysNull, "impossible here");
2153     const TypePtr* ptr = (ptr_kind == ProfileMaybeNull && current_type->speculative_maybe_null()) ? TypePtr::BOTTOM : TypePtr::NOTNULL;
2154     // record the new speculative type's depth
2155     speculative = xtype->cast_to_ptr_type(ptr->ptr())->is_ptr();
2156     speculative = speculative->with_inline_depth(jvms()->depth());
2157   } else if (current_type->would_improve_ptr(ptr_kind)) {
2158     // Profiling report that null was never seen so we can change the
2159     // speculative type to non null ptr.
2160     if (ptr_kind == ProfileAlwaysNull) {
2161       speculative = TypePtr::NULL_PTR;
2162     } else {
2163       assert(ptr_kind == ProfileNeverNull, "nothing else is an improvement");
2164       const TypePtr* ptr = TypePtr::NOTNULL;
2165       if (speculative != NULL) {
2166         speculative = speculative->cast_to_ptr_type(ptr->ptr())->is_ptr();
2167       } else {
2168         speculative = ptr;
2169       }
2170     }
2171   }
2172 
2173   if (speculative != current_type->speculative()) {
2174     // Build a type with a speculative type (what we think we know
2175     // about the type but will need a guard when we use it)
2176     const TypeOopPtr* spec_type = TypeOopPtr::make(TypePtr::BotPTR, Type::OffsetBot, TypeOopPtr::InstanceBot, speculative);
2177     // We're changing the type, we need a new CheckCast node to carry
2178     // the new type. The new type depends on the control: what
2179     // profiling tells us is only valid from here as far as we can
2180     // tell.
2181     Node* cast = new CheckCastPPNode(control(), n, current_type->remove_speculative()->join_speculative(spec_type));
2182     cast = _gvn.transform(cast);
2183     replace_in_map(n, cast);
2184     n = cast;
2185   }
2186 
2187   return n;
2188 }
2189 
2190 /**
2191  * Record profiling data from receiver profiling at an invoke with the
2192  * type system so that it can propagate it (speculation)
2193  *
2194  * @param n  receiver node
2195  *
2196  * @return   node with improved type
2197  */
2198 Node* GraphKit::record_profiled_receiver_for_speculation(Node* n) {
2199   if (!UseTypeSpeculation) {
2200     return n;
2201   }
2202   ciKlass* exact_kls = profile_has_unique_klass();
2203   ProfilePtrKind ptr_kind = ProfileMaybeNull;
2204   if ((java_bc() == Bytecodes::_checkcast ||
2205        java_bc() == Bytecodes::_instanceof ||
2206        java_bc() == Bytecodes::_aastore) &&
2207       method()->method_data()->is_mature()) {
2208     ciProfileData* data = method()->method_data()->bci_to_data(bci());
2209     if (data != NULL) {
2210       if (!data->as_BitData()->null_seen()) {
2211         ptr_kind = ProfileNeverNull;
2212       } else {
2213         assert(data->is_ReceiverTypeData(), "bad profile data type");
2214         ciReceiverTypeData* call = (ciReceiverTypeData*)data->as_ReceiverTypeData();
2215         uint i = 0;
2216         for (; i < call->row_limit(); i++) {
2217           ciKlass* receiver = call->receiver(i);
2218           if (receiver != NULL) {
2219             break;
2220           }
2221         }
2222         ptr_kind = (i == call->row_limit()) ? ProfileAlwaysNull : ProfileMaybeNull;
2223       }
2224     }
2225   }
2226   return record_profile_for_speculation(n, exact_kls, ptr_kind);
2227 }
2228 
2229 /**
2230  * Record profiling data from argument profiling at an invoke with the
2231  * type system so that it can propagate it (speculation)
2232  *
2233  * @param dest_method  target method for the call
2234  * @param bc           what invoke bytecode is this?
2235  */
2236 void GraphKit::record_profiled_arguments_for_speculation(ciMethod* dest_method, Bytecodes::Code bc) {
2237   if (!UseTypeSpeculation) {
2238     return;
2239   }
2240   const TypeFunc* tf    = TypeFunc::make(dest_method);
2241   int             nargs = tf->domain()->cnt() - TypeFunc::Parms;
2242   int skip = Bytecodes::has_receiver(bc) ? 1 : 0;
2243   for (int j = skip, i = 0; j < nargs && i < TypeProfileArgsLimit; j++) {
2244     const Type *targ = tf->domain()->field_at(j + TypeFunc::Parms);
2245     if (targ->basic_type() == T_OBJECT || targ->basic_type() == T_ARRAY) {
2246       ProfilePtrKind ptr_kind = ProfileMaybeNull;
2247       ciKlass* better_type = NULL;
2248       if (method()->argument_profiled_type(bci(), i, better_type, ptr_kind)) {
2249         record_profile_for_speculation(argument(j), better_type, ptr_kind);
2250       }
2251       i++;
2252     }
2253   }
2254 }
2255 
2256 /**
2257  * Record profiling data from parameter profiling at an invoke with
2258  * the type system so that it can propagate it (speculation)
2259  */
2260 void GraphKit::record_profiled_parameters_for_speculation() {
2261   if (!UseTypeSpeculation) {
2262     return;
2263   }
2264   for (int i = 0, j = 0; i < method()->arg_size() ; i++) {
2265     if (_gvn.type(local(i))->isa_oopptr()) {
2266       ProfilePtrKind ptr_kind = ProfileMaybeNull;
2267       ciKlass* better_type = NULL;
2268       if (method()->parameter_profiled_type(j, better_type, ptr_kind)) {
2269         record_profile_for_speculation(local(i), better_type, ptr_kind);
2270       }
2271       j++;
2272     }
2273   }
2274 }
2275 
2276 /**
2277  * Record profiling data from return value profiling at an invoke with
2278  * the type system so that it can propagate it (speculation)
2279  */
2280 void GraphKit::record_profiled_return_for_speculation() {
2281   if (!UseTypeSpeculation) {
2282     return;
2283   }
2284   ProfilePtrKind ptr_kind = ProfileMaybeNull;
2285   ciKlass* better_type = NULL;
2286   if (method()->return_profiled_type(bci(), better_type, ptr_kind)) {
2287     // If profiling reports a single type for the return value,
2288     // feed it to the type system so it can propagate it as a
2289     // speculative type
2290     record_profile_for_speculation(stack(sp()-1), better_type, ptr_kind);
2291   }
2292 }
2293 
2294 void GraphKit::round_double_result(ciMethod* dest_method) {
2295   // A non-strict method may return a double value which has an extended
2296   // exponent, but this must not be visible in a caller which is 'strict'
2297   // If a strict caller invokes a non-strict callee, round a double result
2298 
2299   BasicType result_type = dest_method->return_type()->basic_type();
2300   assert( method() != NULL, "must have caller context");
2301   if( result_type == T_DOUBLE && method()->is_strict() && !dest_method->is_strict() ) {
2302     // Destination method's return value is on top of stack
2303     // dstore_rounding() does gvn.transform
2304     Node *result = pop_pair();
2305     result = dstore_rounding(result);
2306     push_pair(result);
2307   }
2308 }
2309 
2310 // rounding for strict float precision conformance
2311 Node* GraphKit::precision_rounding(Node* n) {
2312   return UseStrictFP && _method->flags().is_strict()
2313     && UseSSE == 0 && Matcher::strict_fp_requires_explicit_rounding
2314     ? _gvn.transform( new RoundFloatNode(0, n) )
2315     : n;
2316 }
2317 
2318 // rounding for strict double precision conformance
2319 Node* GraphKit::dprecision_rounding(Node *n) {
2320   return UseStrictFP && _method->flags().is_strict()
2321     && UseSSE <= 1 && Matcher::strict_fp_requires_explicit_rounding
2322     ? _gvn.transform( new RoundDoubleNode(0, n) )
2323     : n;
2324 }
2325 
2326 // rounding for non-strict double stores
2327 Node* GraphKit::dstore_rounding(Node* n) {
2328   return Matcher::strict_fp_requires_explicit_rounding
2329     && UseSSE <= 1
2330     ? _gvn.transform( new RoundDoubleNode(0, n) )
2331     : n;
2332 }
2333 
2334 //=============================================================================
2335 // Generate a fast path/slow path idiom.  Graph looks like:
2336 // [foo] indicates that 'foo' is a parameter
2337 //
2338 //              [in]     NULL
2339 //                 \    /
2340 //                  CmpP
2341 //                  Bool ne
2342 //                   If
2343 //                  /  \
2344 //              True    False-<2>
2345 //              / |
2346 //             /  cast_not_null
2347 //           Load  |    |   ^
2348 //        [fast_test]   |   |
2349 // gvn to   opt_test    |   |
2350 //          /    \      |  <1>
2351 //      True     False  |
2352 //        |         \\  |
2353 //   [slow_call]     \[fast_result]
2354 //    Ctl   Val       \      \
2355 //     |               \      \
2356 //    Catch       <1>   \      \
2357 //   /    \        ^     \      \
2358 //  Ex    No_Ex    |      \      \
2359 //  |       \   \  |       \ <2>  \
2360 //  ...      \  [slow_res] |  |    \   [null_result]
2361 //            \         \--+--+---  |  |
2362 //             \           | /    \ | /
2363 //              --------Region     Phi
2364 //
2365 //=============================================================================
2366 // Code is structured as a series of driver functions all called 'do_XXX' that
2367 // call a set of helper functions.  Helper functions first, then drivers.
2368 
2369 //------------------------------null_check_oop---------------------------------
2370 // Null check oop.  Set null-path control into Region in slot 3.
2371 // Make a cast-not-nullness use the other not-null control.  Return cast.
2372 Node* GraphKit::null_check_oop(Node* value, Node* *null_control,
2373                                bool never_see_null,
2374                                bool safe_for_replace,
2375                                bool speculative) {
2376   // Initial NULL check taken path
2377   (*null_control) = top();
2378   Node* cast = null_check_common(value, T_OBJECT, false, null_control, speculative);
2379 
2380   // Generate uncommon_trap:
2381   if (never_see_null && (*null_control) != top()) {
2382     // If we see an unexpected null at a check-cast we record it and force a
2383     // recompile; the offending check-cast will be compiled to handle NULLs.
2384     // If we see more than one offending BCI, then all checkcasts in the
2385     // method will be compiled to handle NULLs.
2386     PreserveJVMState pjvms(this);
2387     set_control(*null_control);
2388     replace_in_map(value, null());
2389     Deoptimization::DeoptReason reason = Deoptimization::reason_null_check(speculative);
2390     uncommon_trap(reason,
2391                   Deoptimization::Action_make_not_entrant);
2392     (*null_control) = top();    // NULL path is dead
2393   }
2394   if ((*null_control) == top() && safe_for_replace) {
2395     replace_in_map(value, cast);
2396   }
2397 
2398   // Cast away null-ness on the result
2399   return cast;
2400 }
2401 
2402 //------------------------------opt_iff----------------------------------------
2403 // Optimize the fast-check IfNode.  Set the fast-path region slot 2.
2404 // Return slow-path control.
2405 Node* GraphKit::opt_iff(Node* region, Node* iff) {
2406   IfNode *opt_iff = _gvn.transform(iff)->as_If();
2407 
2408   // Fast path taken; set region slot 2
2409   Node *fast_taken = _gvn.transform( new IfFalseNode(opt_iff) );
2410   region->init_req(2,fast_taken); // Capture fast-control
2411 
2412   // Fast path not-taken, i.e. slow path
2413   Node *slow_taken = _gvn.transform( new IfTrueNode(opt_iff) );
2414   return slow_taken;
2415 }
2416 
2417 //-----------------------------make_runtime_call-------------------------------
2418 Node* GraphKit::make_runtime_call(int flags,
2419                                   const TypeFunc* call_type, address call_addr,
2420                                   const char* call_name,
2421                                   const TypePtr* adr_type,
2422                                   // The following parms are all optional.
2423                                   // The first NULL ends the list.
2424                                   Node* parm0, Node* parm1,
2425                                   Node* parm2, Node* parm3,
2426                                   Node* parm4, Node* parm5,
2427                                   Node* parm6, Node* parm7) {
2428   // Slow-path call
2429   bool is_leaf = !(flags & RC_NO_LEAF);
2430   bool has_io  = (!is_leaf && !(flags & RC_NO_IO));
2431   if (call_name == NULL) {
2432     assert(!is_leaf, "must supply name for leaf");
2433     call_name = OptoRuntime::stub_name(call_addr);
2434   }
2435   CallNode* call;
2436   if (!is_leaf) {
2437     call = new CallStaticJavaNode(call_type, call_addr, call_name,
2438                                            bci(), adr_type);
2439   } else if (flags & RC_NO_FP) {
2440     call = new CallLeafNoFPNode(call_type, call_addr, call_name, adr_type);
2441   } else {
2442     call = new CallLeafNode(call_type, call_addr, call_name, adr_type);
2443   }
2444 
2445   // The following is similar to set_edges_for_java_call,
2446   // except that the memory effects of the call are restricted to AliasIdxRaw.
2447 
2448   // Slow path call has no side-effects, uses few values
2449   bool wide_in  = !(flags & RC_NARROW_MEM);
2450   bool wide_out = (C->get_alias_index(adr_type) == Compile::AliasIdxBot);
2451 
2452   Node* prev_mem = NULL;
2453   if (wide_in) {
2454     prev_mem = set_predefined_input_for_runtime_call(call);
2455   } else {
2456     assert(!wide_out, "narrow in => narrow out");
2457     Node* narrow_mem = memory(adr_type);
2458     prev_mem = reset_memory();
2459     map()->set_memory(narrow_mem);
2460     set_predefined_input_for_runtime_call(call);
2461   }
2462 
2463   // Hook each parm in order.  Stop looking at the first NULL.
2464   if (parm0 != NULL) { call->init_req(TypeFunc::Parms+0, parm0);
2465   if (parm1 != NULL) { call->init_req(TypeFunc::Parms+1, parm1);
2466   if (parm2 != NULL) { call->init_req(TypeFunc::Parms+2, parm2);
2467   if (parm3 != NULL) { call->init_req(TypeFunc::Parms+3, parm3);
2468   if (parm4 != NULL) { call->init_req(TypeFunc::Parms+4, parm4);
2469   if (parm5 != NULL) { call->init_req(TypeFunc::Parms+5, parm5);
2470   if (parm6 != NULL) { call->init_req(TypeFunc::Parms+6, parm6);
2471   if (parm7 != NULL) { call->init_req(TypeFunc::Parms+7, parm7);
2472     /* close each nested if ===> */  } } } } } } } }
2473   assert(call->in(call->req()-1) != NULL, "must initialize all parms");
2474 
2475   if (!is_leaf) {
2476     // Non-leaves can block and take safepoints:
2477     add_safepoint_edges(call, ((flags & RC_MUST_THROW) != 0));
2478   }
2479   // Non-leaves can throw exceptions:
2480   if (has_io) {
2481     call->set_req(TypeFunc::I_O, i_o());
2482   }
2483 
2484   if (flags & RC_UNCOMMON) {
2485     // Set the count to a tiny probability.  Cf. Estimate_Block_Frequency.
2486     // (An "if" probability corresponds roughly to an unconditional count.
2487     // Sort of.)
2488     call->set_cnt(PROB_UNLIKELY_MAG(4));
2489   }
2490 
2491   Node* c = _gvn.transform(call);
2492   assert(c == call, "cannot disappear");
2493 
2494   if (wide_out) {
2495     // Slow path call has full side-effects.
2496     set_predefined_output_for_runtime_call(call);
2497   } else {
2498     // Slow path call has few side-effects, and/or sets few values.
2499     set_predefined_output_for_runtime_call(call, prev_mem, adr_type);
2500   }
2501 
2502   if (has_io) {
2503     set_i_o(_gvn.transform(new ProjNode(call, TypeFunc::I_O)));
2504   }
2505   return call;
2506 
2507 }
2508 
2509 //------------------------------merge_memory-----------------------------------
2510 // Merge memory from one path into the current memory state.
2511 void GraphKit::merge_memory(Node* new_mem, Node* region, int new_path) {
2512   for (MergeMemStream mms(merged_memory(), new_mem->as_MergeMem()); mms.next_non_empty2(); ) {
2513     Node* old_slice = mms.force_memory();
2514     Node* new_slice = mms.memory2();
2515     if (old_slice != new_slice) {
2516       PhiNode* phi;
2517       if (old_slice->is_Phi() && old_slice->as_Phi()->region() == region) {
2518         if (mms.is_empty()) {
2519           // clone base memory Phi's inputs for this memory slice
2520           assert(old_slice == mms.base_memory(), "sanity");
2521           phi = PhiNode::make(region, NULL, Type::MEMORY, mms.adr_type(C));
2522           _gvn.set_type(phi, Type::MEMORY);
2523           for (uint i = 1; i < phi->req(); i++) {
2524             phi->init_req(i, old_slice->in(i));
2525           }
2526         } else {
2527           phi = old_slice->as_Phi(); // Phi was generated already
2528         }
2529       } else {
2530         phi = PhiNode::make(region, old_slice, Type::MEMORY, mms.adr_type(C));
2531         _gvn.set_type(phi, Type::MEMORY);
2532       }
2533       phi->set_req(new_path, new_slice);
2534       mms.set_memory(phi);
2535     }
2536   }
2537 }
2538 
2539 //------------------------------make_slow_call_ex------------------------------
2540 // Make the exception handler hookups for the slow call
2541 void GraphKit::make_slow_call_ex(Node* call, ciInstanceKlass* ex_klass, bool separate_io_proj, bool deoptimize) {
2542   if (stopped())  return;
2543 
2544   // Make a catch node with just two handlers:  fall-through and catch-all
2545   Node* i_o  = _gvn.transform( new ProjNode(call, TypeFunc::I_O, separate_io_proj) );
2546   Node* catc = _gvn.transform( new CatchNode(control(), i_o, 2) );
2547   Node* norm = _gvn.transform( new CatchProjNode(catc, CatchProjNode::fall_through_index, CatchProjNode::no_handler_bci) );
2548   Node* excp = _gvn.transform( new CatchProjNode(catc, CatchProjNode::catch_all_index,    CatchProjNode::no_handler_bci) );
2549 
2550   { PreserveJVMState pjvms(this);
2551     set_control(excp);
2552     set_i_o(i_o);
2553 
2554     if (excp != top()) {
2555       if (deoptimize) {
2556         // Deoptimize if an exception is caught. Don't construct exception state in this case.
2557         uncommon_trap(Deoptimization::Reason_unhandled,
2558                       Deoptimization::Action_none);
2559       } else {
2560         // Create an exception state also.
2561         // Use an exact type if the caller has specified a specific exception.
2562         const Type* ex_type = TypeOopPtr::make_from_klass_unique(ex_klass)->cast_to_ptr_type(TypePtr::NotNull);
2563         Node*       ex_oop  = new CreateExNode(ex_type, control(), i_o);
2564         add_exception_state(make_exception_state(_gvn.transform(ex_oop)));
2565       }
2566     }
2567   }
2568 
2569   // Get the no-exception control from the CatchNode.
2570   set_control(norm);
2571 }
2572 
2573 static IfNode* gen_subtype_check_compare(Node* ctrl, Node* in1, Node* in2, BoolTest::mask test, float p, PhaseGVN* gvn, BasicType bt) {
2574   Node* cmp = NULL;
2575   switch(bt) {
2576   case T_INT: cmp = new CmpINode(in1, in2); break;
2577   case T_ADDRESS: cmp = new CmpPNode(in1, in2); break;
2578   default: fatal("unexpected comparison type %s", type2name(bt));
2579   }
2580   gvn->transform(cmp);
2581   Node* bol = gvn->transform(new BoolNode(cmp, test));
2582   IfNode* iff = new IfNode(ctrl, bol, p, COUNT_UNKNOWN);
2583   gvn->transform(iff);
2584   if (!bol->is_Con()) gvn->record_for_igvn(iff);
2585   return iff;
2586 }
2587 
2588 
2589 //-------------------------------gen_subtype_check-----------------------------
2590 // Generate a subtyping check.  Takes as input the subtype and supertype.
2591 // Returns 2 values: sets the default control() to the true path and returns
2592 // the false path.  Only reads invariant memory; sets no (visible) memory.
2593 // The PartialSubtypeCheckNode sets the hidden 1-word cache in the encoding
2594 // but that's not exposed to the optimizer.  This call also doesn't take in an
2595 // Object; if you wish to check an Object you need to load the Object's class
2596 // prior to coming here.
2597 Node* Phase::gen_subtype_check(Node* subklass, Node* superklass, Node** ctrl, MergeMemNode* mem, PhaseGVN* gvn) {
2598   Compile* C = gvn->C;
2599 
2600   if ((*ctrl)->is_top()) {
2601     return C->top();
2602   }
2603 
2604   // Fast check for identical types, perhaps identical constants.
2605   // The types can even be identical non-constants, in cases
2606   // involving Array.newInstance, Object.clone, etc.
2607   if (subklass == superklass)
2608     return C->top();             // false path is dead; no test needed.
2609 
2610   if (gvn->type(superklass)->singleton()) {
2611     ciKlass* superk = gvn->type(superklass)->is_klassptr()->klass();
2612     ciKlass* subk   = gvn->type(subklass)->is_klassptr()->klass();
2613 
2614     // In the common case of an exact superklass, try to fold up the
2615     // test before generating code.  You may ask, why not just generate
2616     // the code and then let it fold up?  The answer is that the generated
2617     // code will necessarily include null checks, which do not always
2618     // completely fold away.  If they are also needless, then they turn
2619     // into a performance loss.  Example:
2620     //    Foo[] fa = blah(); Foo x = fa[0]; fa[1] = x;
2621     // Here, the type of 'fa' is often exact, so the store check
2622     // of fa[1]=x will fold up, without testing the nullness of x.
2623     switch (C->static_subtype_check(superk, subk)) {
2624     case Compile::SSC_always_false:
2625       {
2626         Node* always_fail = *ctrl;
2627         *ctrl = gvn->C->top();
2628         return always_fail;
2629       }
2630     case Compile::SSC_always_true:
2631       return C->top();
2632     case Compile::SSC_easy_test:
2633       {
2634         // Just do a direct pointer compare and be done.
2635         IfNode* iff = gen_subtype_check_compare(*ctrl, subklass, superklass, BoolTest::eq, PROB_STATIC_FREQUENT, gvn, T_ADDRESS);
2636         *ctrl = gvn->transform(new IfTrueNode(iff));
2637         return gvn->transform(new IfFalseNode(iff));
2638       }
2639     case Compile::SSC_full_test:
2640       break;
2641     default:
2642       ShouldNotReachHere();
2643     }
2644   }
2645 
2646   // %%% Possible further optimization:  Even if the superklass is not exact,
2647   // if the subklass is the unique subtype of the superklass, the check
2648   // will always succeed.  We could leave a dependency behind to ensure this.
2649 
2650   // First load the super-klass's check-offset
2651   Node *p1 = gvn->transform(new AddPNode(superklass, superklass, gvn->MakeConX(in_bytes(Klass::super_check_offset_offset()))));
2652   Node* m = mem->memory_at(C->get_alias_index(gvn->type(p1)->is_ptr()));
2653   Node *chk_off = gvn->transform(new LoadINode(NULL, m, p1, gvn->type(p1)->is_ptr(), TypeInt::INT, MemNode::unordered));
2654   int cacheoff_con = in_bytes(Klass::secondary_super_cache_offset());
2655   bool might_be_cache = (gvn->find_int_con(chk_off, cacheoff_con) == cacheoff_con);
2656 
2657   // Load from the sub-klass's super-class display list, or a 1-word cache of
2658   // the secondary superclass list, or a failing value with a sentinel offset
2659   // if the super-klass is an interface or exceptionally deep in the Java
2660   // hierarchy and we have to scan the secondary superclass list the hard way.
2661   // Worst-case type is a little odd: NULL is allowed as a result (usually
2662   // klass loads can never produce a NULL).
2663   Node *chk_off_X = chk_off;
2664 #ifdef _LP64
2665   chk_off_X = gvn->transform(new ConvI2LNode(chk_off_X));
2666 #endif
2667   Node *p2 = gvn->transform(new AddPNode(subklass,subklass,chk_off_X));
2668   // For some types like interfaces the following loadKlass is from a 1-word
2669   // cache which is mutable so can't use immutable memory.  Other
2670   // types load from the super-class display table which is immutable.
2671   m = mem->memory_at(C->get_alias_index(gvn->type(p2)->is_ptr()));
2672   Node *kmem = might_be_cache ? m : C->immutable_memory();
2673   Node *nkls = gvn->transform(LoadKlassNode::make(*gvn, NULL, kmem, p2, gvn->type(p2)->is_ptr(), TypeKlassPtr::OBJECT_OR_NULL));
2674 
2675   // Compile speed common case: ARE a subtype and we canNOT fail
2676   if( superklass == nkls )
2677     return C->top();             // false path is dead; no test needed.
2678 
2679   // See if we get an immediate positive hit.  Happens roughly 83% of the
2680   // time.  Test to see if the value loaded just previously from the subklass
2681   // is exactly the superklass.
2682   IfNode *iff1 = gen_subtype_check_compare(*ctrl, superklass, nkls, BoolTest::eq, PROB_LIKELY(0.83f), gvn, T_ADDRESS);
2683   Node *iftrue1 = gvn->transform( new IfTrueNode (iff1));
2684   *ctrl = gvn->transform(new IfFalseNode(iff1));
2685 
2686   // Compile speed common case: Check for being deterministic right now.  If
2687   // chk_off is a constant and not equal to cacheoff then we are NOT a
2688   // subklass.  In this case we need exactly the 1 test above and we can
2689   // return those results immediately.
2690   if (!might_be_cache) {
2691     Node* not_subtype_ctrl = *ctrl;
2692     *ctrl = iftrue1; // We need exactly the 1 test above
2693     return not_subtype_ctrl;
2694   }
2695 
2696   // Gather the various success & failures here
2697   RegionNode *r_ok_subtype = new RegionNode(4);
2698   gvn->record_for_igvn(r_ok_subtype);
2699   RegionNode *r_not_subtype = new RegionNode(3);
2700   gvn->record_for_igvn(r_not_subtype);
2701 
2702   r_ok_subtype->init_req(1, iftrue1);
2703 
2704   // Check for immediate negative hit.  Happens roughly 11% of the time (which
2705   // is roughly 63% of the remaining cases).  Test to see if the loaded
2706   // check-offset points into the subklass display list or the 1-element
2707   // cache.  If it points to the display (and NOT the cache) and the display
2708   // missed then it's not a subtype.
2709   Node *cacheoff = gvn->intcon(cacheoff_con);
2710   IfNode *iff2 = gen_subtype_check_compare(*ctrl, chk_off, cacheoff, BoolTest::ne, PROB_LIKELY(0.63f), gvn, T_INT);
2711   r_not_subtype->init_req(1, gvn->transform(new IfTrueNode (iff2)));
2712   *ctrl = gvn->transform(new IfFalseNode(iff2));
2713 
2714   // Check for self.  Very rare to get here, but it is taken 1/3 the time.
2715   // No performance impact (too rare) but allows sharing of secondary arrays
2716   // which has some footprint reduction.
2717   IfNode *iff3 = gen_subtype_check_compare(*ctrl, subklass, superklass, BoolTest::eq, PROB_LIKELY(0.36f), gvn, T_ADDRESS);
2718   r_ok_subtype->init_req(2, gvn->transform(new IfTrueNode(iff3)));
2719   *ctrl = gvn->transform(new IfFalseNode(iff3));
2720 
2721   // -- Roads not taken here: --
2722   // We could also have chosen to perform the self-check at the beginning
2723   // of this code sequence, as the assembler does.  This would not pay off
2724   // the same way, since the optimizer, unlike the assembler, can perform
2725   // static type analysis to fold away many successful self-checks.
2726   // Non-foldable self checks work better here in second position, because
2727   // the initial primary superclass check subsumes a self-check for most
2728   // types.  An exception would be a secondary type like array-of-interface,
2729   // which does not appear in its own primary supertype display.
2730   // Finally, we could have chosen to move the self-check into the
2731   // PartialSubtypeCheckNode, and from there out-of-line in a platform
2732   // dependent manner.  But it is worthwhile to have the check here,
2733   // where it can be perhaps be optimized.  The cost in code space is
2734   // small (register compare, branch).
2735 
2736   // Now do a linear scan of the secondary super-klass array.  Again, no real
2737   // performance impact (too rare) but it's gotta be done.
2738   // Since the code is rarely used, there is no penalty for moving it
2739   // out of line, and it can only improve I-cache density.
2740   // The decision to inline or out-of-line this final check is platform
2741   // dependent, and is found in the AD file definition of PartialSubtypeCheck.
2742   Node* psc = gvn->transform(
2743     new PartialSubtypeCheckNode(*ctrl, subklass, superklass));
2744 
2745   IfNode *iff4 = gen_subtype_check_compare(*ctrl, psc, gvn->zerocon(T_OBJECT), BoolTest::ne, PROB_FAIR, gvn, T_ADDRESS);
2746   r_not_subtype->init_req(2, gvn->transform(new IfTrueNode (iff4)));
2747   r_ok_subtype ->init_req(3, gvn->transform(new IfFalseNode(iff4)));
2748 
2749   // Return false path; set default control to true path.
2750   *ctrl = gvn->transform(r_ok_subtype);
2751   return gvn->transform(r_not_subtype);
2752 }
2753 
2754 // Profile-driven exact type check:
2755 Node* GraphKit::type_check_receiver(Node* receiver, ciKlass* klass,
2756                                     float prob,
2757                                     Node* *casted_receiver) {
2758   const TypeKlassPtr* tklass = TypeKlassPtr::make(klass);
2759   Node* recv_klass = load_object_klass(receiver);
2760   Node* want_klass = makecon(tklass);
2761   Node* cmp = _gvn.transform( new CmpPNode(recv_klass, want_klass) );
2762   Node* bol = _gvn.transform( new BoolNode(cmp, BoolTest::eq) );
2763   IfNode* iff = create_and_xform_if(control(), bol, prob, COUNT_UNKNOWN);
2764   set_control( _gvn.transform( new IfTrueNode (iff) ));
2765   Node* fail = _gvn.transform( new IfFalseNode(iff) );
2766 
2767   const TypeOopPtr* recv_xtype = tklass->as_instance_type();
2768   assert(recv_xtype->klass_is_exact(), "");
2769 
2770   // Subsume downstream occurrences of receiver with a cast to
2771   // recv_xtype, since now we know what the type will be.
2772   Node* cast = new CheckCastPPNode(control(), receiver, recv_xtype);
2773   (*casted_receiver) = _gvn.transform(cast);
2774   // (User must make the replace_in_map call.)
2775 
2776   return fail;
2777 }
2778 
2779 
2780 //------------------------------seems_never_null-------------------------------
2781 // Use null_seen information if it is available from the profile.
2782 // If we see an unexpected null at a type check we record it and force a
2783 // recompile; the offending check will be recompiled to handle NULLs.
2784 // If we see several offending BCIs, then all checks in the
2785 // method will be recompiled.
2786 bool GraphKit::seems_never_null(Node* obj, ciProfileData* data, bool& speculating) {
2787   speculating = !_gvn.type(obj)->speculative_maybe_null();
2788   Deoptimization::DeoptReason reason = Deoptimization::reason_null_check(speculating);
2789   if (UncommonNullCast               // Cutout for this technique
2790       && obj != null()               // And not the -Xcomp stupid case?
2791       && !too_many_traps(reason)
2792       ) {
2793     if (speculating) {
2794       return true;
2795     }
2796     if (data == NULL)
2797       // Edge case:  no mature data.  Be optimistic here.
2798       return true;
2799     // If the profile has not seen a null, assume it won't happen.
2800     assert(java_bc() == Bytecodes::_checkcast ||
2801            java_bc() == Bytecodes::_instanceof ||
2802            java_bc() == Bytecodes::_aastore, "MDO must collect null_seen bit here");
2803     return !data->as_BitData()->null_seen();
2804   }
2805   speculating = false;
2806   return false;
2807 }
2808 
2809 //------------------------maybe_cast_profiled_receiver-------------------------
2810 // If the profile has seen exactly one type, narrow to exactly that type.
2811 // Subsequent type checks will always fold up.
2812 Node* GraphKit::maybe_cast_profiled_receiver(Node* not_null_obj,
2813                                              ciKlass* require_klass,
2814                                              ciKlass* spec_klass,
2815                                              bool safe_for_replace) {
2816   if (!UseTypeProfile || !TypeProfileCasts) return NULL;
2817 
2818   Deoptimization::DeoptReason reason = Deoptimization::reason_class_check(spec_klass != NULL);
2819 
2820   // Make sure we haven't already deoptimized from this tactic.
2821   if (too_many_traps(reason) || too_many_recompiles(reason))
2822     return NULL;
2823 
2824   // (No, this isn't a call, but it's enough like a virtual call
2825   // to use the same ciMethod accessor to get the profile info...)
2826   // If we have a speculative type use it instead of profiling (which
2827   // may not help us)
2828   ciKlass* exact_kls = spec_klass == NULL ? profile_has_unique_klass() : spec_klass;
2829   if (exact_kls != NULL) {// no cast failures here
2830     if (require_klass == NULL ||
2831         C->static_subtype_check(require_klass, exact_kls) == Compile::SSC_always_true) {
2832       // If we narrow the type to match what the type profile sees or
2833       // the speculative type, we can then remove the rest of the
2834       // cast.
2835       // This is a win, even if the exact_kls is very specific,
2836       // because downstream operations, such as method calls,
2837       // will often benefit from the sharper type.
2838       Node* exact_obj = not_null_obj; // will get updated in place...
2839       Node* slow_ctl  = type_check_receiver(exact_obj, exact_kls, 1.0,
2840                                             &exact_obj);
2841       { PreserveJVMState pjvms(this);
2842         set_control(slow_ctl);
2843         uncommon_trap_exact(reason, Deoptimization::Action_maybe_recompile);
2844       }
2845       if (safe_for_replace) {
2846         replace_in_map(not_null_obj, exact_obj);
2847       }
2848       return exact_obj;
2849     }
2850     // assert(ssc == Compile::SSC_always_true)... except maybe the profile lied to us.
2851   }
2852 
2853   return NULL;
2854 }
2855 
2856 /**
2857  * Cast obj to type and emit guard unless we had too many traps here
2858  * already
2859  *
2860  * @param obj       node being casted
2861  * @param type      type to cast the node to
2862  * @param not_null  true if we know node cannot be null
2863  */
2864 Node* GraphKit::maybe_cast_profiled_obj(Node* obj,
2865                                         ciKlass* type,
2866                                         bool not_null) {
2867   if (stopped()) {
2868     return obj;
2869   }
2870 
2871   // type == NULL if profiling tells us this object is always null
2872   if (type != NULL) {
2873     Deoptimization::DeoptReason class_reason = Deoptimization::Reason_speculate_class_check;
2874     Deoptimization::DeoptReason null_reason = Deoptimization::Reason_speculate_null_check;
2875 
2876     if (!too_many_traps(null_reason) && !too_many_recompiles(null_reason) &&
2877         !too_many_traps(class_reason) &&
2878         !too_many_recompiles(class_reason)) {
2879       Node* not_null_obj = NULL;
2880       // not_null is true if we know the object is not null and
2881       // there's no need for a null check
2882       if (!not_null) {
2883         Node* null_ctl = top();
2884         not_null_obj = null_check_oop(obj, &null_ctl, true, true, true);
2885         assert(null_ctl->is_top(), "no null control here");
2886       } else {
2887         not_null_obj = obj;
2888       }
2889 
2890       Node* exact_obj = not_null_obj;
2891       ciKlass* exact_kls = type;
2892       Node* slow_ctl  = type_check_receiver(exact_obj, exact_kls, 1.0,
2893                                             &exact_obj);
2894       {
2895         PreserveJVMState pjvms(this);
2896         set_control(slow_ctl);
2897         uncommon_trap_exact(class_reason, Deoptimization::Action_maybe_recompile);
2898       }
2899       replace_in_map(not_null_obj, exact_obj);
2900       obj = exact_obj;
2901     }
2902   } else {
2903     if (!too_many_traps(Deoptimization::Reason_null_assert) &&
2904         !too_many_recompiles(Deoptimization::Reason_null_assert)) {
2905       Node* exact_obj = null_assert(obj);
2906       replace_in_map(obj, exact_obj);
2907       obj = exact_obj;
2908     }
2909   }
2910   return obj;
2911 }
2912 
2913 //-------------------------------gen_instanceof--------------------------------
2914 // Generate an instance-of idiom.  Used by both the instance-of bytecode
2915 // and the reflective instance-of call.
2916 Node* GraphKit::gen_instanceof(Node* obj, Node* superklass, bool safe_for_replace) {
2917   kill_dead_locals();           // Benefit all the uncommon traps
2918   assert( !stopped(), "dead parse path should be checked in callers" );
2919   assert(!TypePtr::NULL_PTR->higher_equal(_gvn.type(superklass)->is_klassptr()),
2920          "must check for not-null not-dead klass in callers");
2921 
2922   // Make the merge point
2923   enum { _obj_path = 1, _fail_path, _null_path, PATH_LIMIT };
2924   RegionNode* region = new RegionNode(PATH_LIMIT);
2925   Node*       phi    = new PhiNode(region, TypeInt::BOOL);
2926   C->set_has_split_ifs(true); // Has chance for split-if optimization
2927 
2928   ciProfileData* data = NULL;
2929   if (java_bc() == Bytecodes::_instanceof) {  // Only for the bytecode
2930     data = method()->method_data()->bci_to_data(bci());
2931   }
2932   bool speculative_not_null = false;
2933   bool never_see_null = (ProfileDynamicTypes  // aggressive use of profile
2934                          && seems_never_null(obj, data, speculative_not_null));
2935 
2936   // Null check; get casted pointer; set region slot 3
2937   Node* null_ctl = top();
2938   Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null, safe_for_replace, speculative_not_null);
2939 
2940   // If not_null_obj is dead, only null-path is taken
2941   if (stopped()) {              // Doing instance-of on a NULL?
2942     set_control(null_ctl);
2943     return intcon(0);
2944   }
2945   region->init_req(_null_path, null_ctl);
2946   phi   ->init_req(_null_path, intcon(0)); // Set null path value
2947   if (null_ctl == top()) {
2948     // Do this eagerly, so that pattern matches like is_diamond_phi
2949     // will work even during parsing.
2950     assert(_null_path == PATH_LIMIT-1, "delete last");
2951     region->del_req(_null_path);
2952     phi   ->del_req(_null_path);
2953   }
2954 
2955   // Do we know the type check always succeed?
2956   bool known_statically = false;
2957   if (_gvn.type(superklass)->singleton()) {
2958     ciKlass* superk = _gvn.type(superklass)->is_klassptr()->klass();
2959     ciKlass* subk = _gvn.type(obj)->is_oopptr()->klass();
2960     if (subk != NULL && subk->is_loaded()) {
2961       int static_res = C->static_subtype_check(superk, subk);
2962       known_statically = (static_res == Compile::SSC_always_true || static_res == Compile::SSC_always_false);
2963     }
2964   }
2965 
2966   if (!known_statically) {
2967     const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
2968     // We may not have profiling here or it may not help us. If we
2969     // have a speculative type use it to perform an exact cast.
2970     ciKlass* spec_obj_type = obj_type->speculative_type();
2971     if (spec_obj_type != NULL || (ProfileDynamicTypes && data != NULL)) {
2972       Node* cast_obj = maybe_cast_profiled_receiver(not_null_obj, NULL, spec_obj_type, safe_for_replace);
2973       if (stopped()) {            // Profile disagrees with this path.
2974         set_control(null_ctl);    // Null is the only remaining possibility.
2975         return intcon(0);
2976       }
2977       if (cast_obj != NULL) {
2978         not_null_obj = cast_obj;
2979       }
2980     }
2981   }
2982 
2983   // Load the object's klass
2984   Node* obj_klass = load_object_klass(not_null_obj);
2985 
2986   // Generate the subtype check
2987   Node* not_subtype_ctrl = gen_subtype_check(obj_klass, superklass);
2988 
2989   // Plug in the success path to the general merge in slot 1.
2990   region->init_req(_obj_path, control());
2991   phi   ->init_req(_obj_path, intcon(1));
2992 
2993   // Plug in the failing path to the general merge in slot 2.
2994   region->init_req(_fail_path, not_subtype_ctrl);
2995   phi   ->init_req(_fail_path, intcon(0));
2996 
2997   // Return final merged results
2998   set_control( _gvn.transform(region) );
2999   record_for_igvn(region);
3000 
3001   // If we know the type check always succeeds then we don't use the
3002   // profiling data at this bytecode. Don't lose it, feed it to the
3003   // type system as a speculative type.
3004   if (safe_for_replace) {
3005     Node* casted_obj = record_profiled_receiver_for_speculation(obj);
3006     replace_in_map(obj, casted_obj);
3007   }
3008 
3009   return _gvn.transform(phi);
3010 }
3011 
3012 //-------------------------------gen_checkcast---------------------------------
3013 // Generate a checkcast idiom.  Used by both the checkcast bytecode and the
3014 // array store bytecode.  Stack must be as-if BEFORE doing the bytecode so the
3015 // uncommon-trap paths work.  Adjust stack after this call.
3016 // If failure_control is supplied and not null, it is filled in with
3017 // the control edge for the cast failure.  Otherwise, an appropriate
3018 // uncommon trap or exception is thrown.
3019 Node* GraphKit::gen_checkcast(Node *obj, Node* superklass,
3020                               Node* *failure_control) {
3021   kill_dead_locals();           // Benefit all the uncommon traps
3022   const TypeKlassPtr *tk = _gvn.type(superklass)->is_klassptr();
3023   const Type *toop = TypeOopPtr::make_from_klass(tk->klass());
3024 
3025   // Fast cutout:  Check the case that the cast is vacuously true.
3026   // This detects the common cases where the test will short-circuit
3027   // away completely.  We do this before we perform the null check,
3028   // because if the test is going to turn into zero code, we don't
3029   // want a residual null check left around.  (Causes a slowdown,
3030   // for example, in some objArray manipulations, such as a[i]=a[j].)
3031   if (tk->singleton()) {
3032     const TypeOopPtr* objtp = _gvn.type(obj)->isa_oopptr();
3033     if (objtp != NULL && objtp->klass() != NULL) {
3034       switch (C->static_subtype_check(tk->klass(), objtp->klass())) {
3035       case Compile::SSC_always_true:
3036         // If we know the type check always succeed then we don't use
3037         // the profiling data at this bytecode. Don't lose it, feed it
3038         // to the type system as a speculative type.
3039         return record_profiled_receiver_for_speculation(obj);
3040       case Compile::SSC_always_false:
3041         // It needs a null check because a null will *pass* the cast check.
3042         // A non-null value will always produce an exception.
3043         return null_assert(obj);
3044       }
3045     }
3046   }
3047 
3048   ciProfileData* data = NULL;
3049   bool safe_for_replace = false;
3050   if (failure_control == NULL) {        // use MDO in regular case only
3051     assert(java_bc() == Bytecodes::_aastore ||
3052            java_bc() == Bytecodes::_checkcast,
3053            "interpreter profiles type checks only for these BCs");
3054     data = method()->method_data()->bci_to_data(bci());
3055     safe_for_replace = true;
3056   }
3057 
3058   // Make the merge point
3059   enum { _obj_path = 1, _null_path, PATH_LIMIT };
3060   RegionNode* region = new RegionNode(PATH_LIMIT);
3061   Node*       phi    = new PhiNode(region, toop);
3062   C->set_has_split_ifs(true); // Has chance for split-if optimization
3063 
3064   // Use null-cast information if it is available
3065   bool speculative_not_null = false;
3066   bool never_see_null = ((failure_control == NULL)  // regular case only
3067                          && seems_never_null(obj, data, speculative_not_null));
3068 
3069   // Null check; get casted pointer; set region slot 3
3070   Node* null_ctl = top();
3071   Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null, safe_for_replace, speculative_not_null);
3072 
3073   // If not_null_obj is dead, only null-path is taken
3074   if (stopped()) {              // Doing instance-of on a NULL?
3075     set_control(null_ctl);
3076     return null();
3077   }
3078   region->init_req(_null_path, null_ctl);
3079   phi   ->init_req(_null_path, null());  // Set null path value
3080   if (null_ctl == top()) {
3081     // Do this eagerly, so that pattern matches like is_diamond_phi
3082     // will work even during parsing.
3083     assert(_null_path == PATH_LIMIT-1, "delete last");
3084     region->del_req(_null_path);
3085     phi   ->del_req(_null_path);
3086   }
3087 
3088   Node* cast_obj = NULL;
3089   if (tk->klass_is_exact()) {
3090     // The following optimization tries to statically cast the speculative type of the object
3091     // (for example obtained during profiling) to the type of the superklass and then do a
3092     // dynamic check that the type of the object is what we expect. To work correctly
3093     // for checkcast and aastore the type of superklass should be exact.
3094     const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
3095     // We may not have profiling here or it may not help us. If we have
3096     // a speculative type use it to perform an exact cast.
3097     ciKlass* spec_obj_type = obj_type->speculative_type();
3098     if (spec_obj_type != NULL || data != NULL) {
3099       cast_obj = maybe_cast_profiled_receiver(not_null_obj, tk->klass(), spec_obj_type, safe_for_replace);
3100       if (cast_obj != NULL) {
3101         if (failure_control != NULL) // failure is now impossible
3102           (*failure_control) = top();
3103         // adjust the type of the phi to the exact klass:
3104         phi->raise_bottom_type(_gvn.type(cast_obj)->meet_speculative(TypePtr::NULL_PTR));
3105       }
3106     }
3107   }
3108 
3109   if (cast_obj == NULL) {
3110     // Load the object's klass
3111     Node* obj_klass = load_object_klass(not_null_obj);
3112 
3113     // Generate the subtype check
3114     Node* not_subtype_ctrl = gen_subtype_check( obj_klass, superklass );
3115 
3116     // Plug in success path into the merge
3117     cast_obj = _gvn.transform(new CheckCastPPNode(control(), not_null_obj, toop));
3118     // Failure path ends in uncommon trap (or may be dead - failure impossible)
3119     if (failure_control == NULL) {
3120       if (not_subtype_ctrl != top()) { // If failure is possible
3121         PreserveJVMState pjvms(this);
3122         set_control(not_subtype_ctrl);
3123         builtin_throw(Deoptimization::Reason_class_check, obj_klass);
3124       }
3125     } else {
3126       (*failure_control) = not_subtype_ctrl;
3127     }
3128   }
3129 
3130   region->init_req(_obj_path, control());
3131   phi   ->init_req(_obj_path, cast_obj);
3132 
3133   // A merge of NULL or Casted-NotNull obj
3134   Node* res = _gvn.transform(phi);
3135 
3136   // Note I do NOT always 'replace_in_map(obj,result)' here.
3137   //  if( tk->klass()->can_be_primary_super()  )
3138     // This means that if I successfully store an Object into an array-of-String
3139     // I 'forget' that the Object is really now known to be a String.  I have to
3140     // do this because we don't have true union types for interfaces - if I store
3141     // a Baz into an array-of-Interface and then tell the optimizer it's an
3142     // Interface, I forget that it's also a Baz and cannot do Baz-like field
3143     // references to it.  FIX THIS WHEN UNION TYPES APPEAR!
3144   //  replace_in_map( obj, res );
3145 
3146   // Return final merged results
3147   set_control( _gvn.transform(region) );
3148   record_for_igvn(region);
3149 
3150   return record_profiled_receiver_for_speculation(res);
3151 }
3152 
3153 //------------------------------next_monitor-----------------------------------
3154 // What number should be given to the next monitor?
3155 int GraphKit::next_monitor() {
3156   int current = jvms()->monitor_depth()* C->sync_stack_slots();
3157   int next = current + C->sync_stack_slots();
3158   // Keep the toplevel high water mark current:
3159   if (C->fixed_slots() < next)  C->set_fixed_slots(next);
3160   return current;
3161 }
3162 
3163 //------------------------------insert_mem_bar---------------------------------
3164 // Memory barrier to avoid floating things around
3165 // The membar serves as a pinch point between both control and all memory slices.
3166 Node* GraphKit::insert_mem_bar(int opcode, Node* precedent) {
3167   MemBarNode* mb = MemBarNode::make(C, opcode, Compile::AliasIdxBot, precedent);
3168   mb->init_req(TypeFunc::Control, control());
3169   mb->init_req(TypeFunc::Memory,  reset_memory());
3170   Node* membar = _gvn.transform(mb);
3171   set_control(_gvn.transform(new ProjNode(membar, TypeFunc::Control)));
3172   set_all_memory_call(membar);
3173   return membar;
3174 }
3175 
3176 //-------------------------insert_mem_bar_volatile----------------------------
3177 // Memory barrier to avoid floating things around
3178 // The membar serves as a pinch point between both control and memory(alias_idx).
3179 // If you want to make a pinch point on all memory slices, do not use this
3180 // function (even with AliasIdxBot); use insert_mem_bar() instead.
3181 Node* GraphKit::insert_mem_bar_volatile(int opcode, int alias_idx, Node* precedent) {
3182   // When Parse::do_put_xxx updates a volatile field, it appends a series
3183   // of MemBarVolatile nodes, one for *each* volatile field alias category.
3184   // The first membar is on the same memory slice as the field store opcode.
3185   // This forces the membar to follow the store.  (Bug 6500685 broke this.)
3186   // All the other membars (for other volatile slices, including AliasIdxBot,
3187   // which stands for all unknown volatile slices) are control-dependent
3188   // on the first membar.  This prevents later volatile loads or stores
3189   // from sliding up past the just-emitted store.
3190 
3191   MemBarNode* mb = MemBarNode::make(C, opcode, alias_idx, precedent);
3192   mb->set_req(TypeFunc::Control,control());
3193   if (alias_idx == Compile::AliasIdxBot) {
3194     mb->set_req(TypeFunc::Memory, merged_memory()->base_memory());
3195   } else {
3196     assert(!(opcode == Op_Initialize && alias_idx != Compile::AliasIdxRaw), "fix caller");
3197     mb->set_req(TypeFunc::Memory, memory(alias_idx));
3198   }
3199   Node* membar = _gvn.transform(mb);
3200   set_control(_gvn.transform(new ProjNode(membar, TypeFunc::Control)));
3201   if (alias_idx == Compile::AliasIdxBot) {
3202     merged_memory()->set_base_memory(_gvn.transform(new ProjNode(membar, TypeFunc::Memory)));
3203   } else {
3204     set_memory(_gvn.transform(new ProjNode(membar, TypeFunc::Memory)),alias_idx);
3205   }
3206   return membar;
3207 }
3208 
3209 //------------------------------shared_lock------------------------------------
3210 // Emit locking code.
3211 FastLockNode* GraphKit::shared_lock(Node* obj) {
3212   // bci is either a monitorenter bc or InvocationEntryBci
3213   // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
3214   assert(SynchronizationEntryBCI == InvocationEntryBci, "");
3215 
3216   if( !GenerateSynchronizationCode )
3217     return NULL;                // Not locking things?
3218   if (stopped())                // Dead monitor?
3219     return NULL;
3220 
3221   assert(dead_locals_are_killed(), "should kill locals before sync. point");
3222 
3223   // Box the stack location
3224   Node* box = _gvn.transform(new BoxLockNode(next_monitor()));
3225   Node* mem = reset_memory();
3226 
3227   FastLockNode * flock = _gvn.transform(new FastLockNode(0, obj, box) )->as_FastLock();
3228   if (UseBiasedLocking && PrintPreciseBiasedLockingStatistics) {
3229     // Create the counters for this fast lock.
3230     flock->create_lock_counter(sync_jvms()); // sync_jvms used to get current bci
3231   }
3232 
3233   // Create the rtm counters for this fast lock if needed.
3234   flock->create_rtm_lock_counter(sync_jvms()); // sync_jvms used to get current bci
3235 
3236   // Add monitor to debug info for the slow path.  If we block inside the
3237   // slow path and de-opt, we need the monitor hanging around
3238   map()->push_monitor( flock );
3239 
3240   const TypeFunc *tf = LockNode::lock_type();
3241   LockNode *lock = new LockNode(C, tf);
3242 
3243   lock->init_req( TypeFunc::Control, control() );
3244   lock->init_req( TypeFunc::Memory , mem );
3245   lock->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
3246   lock->init_req( TypeFunc::FramePtr, frameptr() );
3247   lock->init_req( TypeFunc::ReturnAdr, top() );
3248 
3249   lock->init_req(TypeFunc::Parms + 0, obj);
3250   lock->init_req(TypeFunc::Parms + 1, box);
3251   lock->init_req(TypeFunc::Parms + 2, flock);
3252   add_safepoint_edges(lock);
3253 
3254   lock = _gvn.transform( lock )->as_Lock();
3255 
3256   // lock has no side-effects, sets few values
3257   set_predefined_output_for_runtime_call(lock, mem, TypeRawPtr::BOTTOM);
3258 
3259   insert_mem_bar(Op_MemBarAcquireLock);
3260 
3261   // Add this to the worklist so that the lock can be eliminated
3262   record_for_igvn(lock);
3263 
3264 #ifndef PRODUCT
3265   if (PrintLockStatistics) {
3266     // Update the counter for this lock.  Don't bother using an atomic
3267     // operation since we don't require absolute accuracy.
3268     lock->create_lock_counter(map()->jvms());
3269     increment_counter(lock->counter()->addr());
3270   }
3271 #endif
3272 
3273   return flock;
3274 }
3275 
3276 
3277 //------------------------------shared_unlock----------------------------------
3278 // Emit unlocking code.
3279 void GraphKit::shared_unlock(Node* box, Node* obj) {
3280   // bci is either a monitorenter bc or InvocationEntryBci
3281   // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
3282   assert(SynchronizationEntryBCI == InvocationEntryBci, "");
3283 
3284   if( !GenerateSynchronizationCode )
3285     return;
3286   if (stopped()) {               // Dead monitor?
3287     map()->pop_monitor();        // Kill monitor from debug info
3288     return;
3289   }
3290 
3291   // Memory barrier to avoid floating things down past the locked region
3292   insert_mem_bar(Op_MemBarReleaseLock);
3293 
3294   const TypeFunc *tf = OptoRuntime::complete_monitor_exit_Type();
3295   UnlockNode *unlock = new UnlockNode(C, tf);
3296 #ifdef ASSERT
3297   unlock->set_dbg_jvms(sync_jvms());
3298 #endif
3299   uint raw_idx = Compile::AliasIdxRaw;
3300   unlock->init_req( TypeFunc::Control, control() );
3301   unlock->init_req( TypeFunc::Memory , memory(raw_idx) );
3302   unlock->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
3303   unlock->init_req( TypeFunc::FramePtr, frameptr() );
3304   unlock->init_req( TypeFunc::ReturnAdr, top() );
3305 
3306   unlock->init_req(TypeFunc::Parms + 0, obj);
3307   unlock->init_req(TypeFunc::Parms + 1, box);
3308   unlock = _gvn.transform(unlock)->as_Unlock();
3309 
3310   Node* mem = reset_memory();
3311 
3312   // unlock has no side-effects, sets few values
3313   set_predefined_output_for_runtime_call(unlock, mem, TypeRawPtr::BOTTOM);
3314 
3315   // Kill monitor from debug info
3316   map()->pop_monitor( );
3317 }
3318 
3319 //-------------------------------get_layout_helper-----------------------------
3320 // If the given klass is a constant or known to be an array,
3321 // fetch the constant layout helper value into constant_value
3322 // and return (Node*)NULL.  Otherwise, load the non-constant
3323 // layout helper value, and return the node which represents it.
3324 // This two-faced routine is useful because allocation sites
3325 // almost always feature constant types.
3326 Node* GraphKit::get_layout_helper(Node* klass_node, jint& constant_value) {
3327   const TypeKlassPtr* inst_klass = _gvn.type(klass_node)->isa_klassptr();
3328   if (!StressReflectiveCode && inst_klass != NULL) {
3329     ciKlass* klass = inst_klass->klass();
3330     bool    xklass = inst_klass->klass_is_exact();
3331     if (xklass || klass->is_array_klass()) {
3332       jint lhelper = klass->layout_helper();
3333       if (lhelper != Klass::_lh_neutral_value) {
3334         constant_value = lhelper;
3335         return (Node*) NULL;
3336       }
3337     }
3338   }
3339   constant_value = Klass::_lh_neutral_value;  // put in a known value
3340   Node* lhp = basic_plus_adr(klass_node, klass_node, in_bytes(Klass::layout_helper_offset()));
3341   return make_load(NULL, lhp, TypeInt::INT, T_INT, MemNode::unordered);
3342 }
3343 
3344 // We just put in an allocate/initialize with a big raw-memory effect.
3345 // Hook selected additional alias categories on the initialization.
3346 static void hook_memory_on_init(GraphKit& kit, int alias_idx,
3347                                 MergeMemNode* init_in_merge,
3348                                 Node* init_out_raw) {
3349   DEBUG_ONLY(Node* init_in_raw = init_in_merge->base_memory());
3350   assert(init_in_merge->memory_at(alias_idx) == init_in_raw, "");
3351 
3352   Node* prevmem = kit.memory(alias_idx);
3353   init_in_merge->set_memory_at(alias_idx, prevmem);
3354   kit.set_memory(init_out_raw, alias_idx);
3355 }
3356 
3357 //---------------------------set_output_for_allocation-------------------------
3358 Node* GraphKit::set_output_for_allocation(AllocateNode* alloc,
3359                                           const TypeOopPtr* oop_type,
3360                                           bool deoptimize_on_exception) {
3361   int rawidx = Compile::AliasIdxRaw;
3362   alloc->set_req( TypeFunc::FramePtr, frameptr() );
3363   add_safepoint_edges(alloc);
3364   Node* allocx = _gvn.transform(alloc);
3365   set_control( _gvn.transform(new ProjNode(allocx, TypeFunc::Control) ) );
3366   // create memory projection for i_o
3367   set_memory ( _gvn.transform( new ProjNode(allocx, TypeFunc::Memory, true) ), rawidx );
3368   make_slow_call_ex(allocx, env()->Throwable_klass(), true, deoptimize_on_exception);
3369 
3370   // create a memory projection as for the normal control path
3371   Node* malloc = _gvn.transform(new ProjNode(allocx, TypeFunc::Memory));
3372   set_memory(malloc, rawidx);
3373 
3374   // a normal slow-call doesn't change i_o, but an allocation does
3375   // we create a separate i_o projection for the normal control path
3376   set_i_o(_gvn.transform( new ProjNode(allocx, TypeFunc::I_O, false) ) );
3377   Node* rawoop = _gvn.transform( new ProjNode(allocx, TypeFunc::Parms) );
3378 
3379   // put in an initialization barrier
3380   InitializeNode* init = insert_mem_bar_volatile(Op_Initialize, rawidx,
3381                                                  rawoop)->as_Initialize();
3382   assert(alloc->initialization() == init,  "2-way macro link must work");
3383   assert(init ->allocation()     == alloc, "2-way macro link must work");
3384   {
3385     // Extract memory strands which may participate in the new object's
3386     // initialization, and source them from the new InitializeNode.
3387     // This will allow us to observe initializations when they occur,
3388     // and link them properly (as a group) to the InitializeNode.
3389     assert(init->in(InitializeNode::Memory) == malloc, "");
3390     MergeMemNode* minit_in = MergeMemNode::make(malloc);
3391     init->set_req(InitializeNode::Memory, minit_in);
3392     record_for_igvn(minit_in); // fold it up later, if possible
3393     Node* minit_out = memory(rawidx);
3394     assert(minit_out->is_Proj() && minit_out->in(0) == init, "");
3395     if (oop_type->isa_aryptr()) {
3396       const TypePtr* telemref = oop_type->add_offset(Type::OffsetBot);
3397       int            elemidx  = C->get_alias_index(telemref);
3398       hook_memory_on_init(*this, elemidx, minit_in, minit_out);
3399     } else if (oop_type->isa_instptr()) {
3400       ciInstanceKlass* ik = oop_type->klass()->as_instance_klass();
3401       for (int i = 0, len = ik->nof_nonstatic_fields(); i < len; i++) {
3402         ciField* field = ik->nonstatic_field_at(i);
3403         if (field->offset() >= TrackedInitializationLimit * HeapWordSize)
3404           continue;  // do not bother to track really large numbers of fields
3405         // Find (or create) the alias category for this field:
3406         int fieldidx = C->alias_type(field)->index();
3407         hook_memory_on_init(*this, fieldidx, minit_in, minit_out);
3408       }
3409     }
3410   }
3411 
3412   // Cast raw oop to the real thing...
3413   Node* javaoop = new CheckCastPPNode(control(), rawoop, oop_type);
3414   javaoop = _gvn.transform(javaoop);
3415   C->set_recent_alloc(control(), javaoop);
3416   assert(just_allocated_object(control()) == javaoop, "just allocated");
3417 
3418 #ifdef ASSERT
3419   { // Verify that the AllocateNode::Ideal_allocation recognizers work:
3420     assert(AllocateNode::Ideal_allocation(rawoop, &_gvn) == alloc,
3421            "Ideal_allocation works");
3422     assert(AllocateNode::Ideal_allocation(javaoop, &_gvn) == alloc,
3423            "Ideal_allocation works");
3424     if (alloc->is_AllocateArray()) {
3425       assert(AllocateArrayNode::Ideal_array_allocation(rawoop, &_gvn) == alloc->as_AllocateArray(),
3426              "Ideal_allocation works");
3427       assert(AllocateArrayNode::Ideal_array_allocation(javaoop, &_gvn) == alloc->as_AllocateArray(),
3428              "Ideal_allocation works");
3429     } else {
3430       assert(alloc->in(AllocateNode::ALength)->is_top(), "no length, please");
3431     }
3432   }
3433 #endif //ASSERT
3434 
3435   return javaoop;
3436 }
3437 
3438 //---------------------------new_instance--------------------------------------
3439 // This routine takes a klass_node which may be constant (for a static type)
3440 // or may be non-constant (for reflective code).  It will work equally well
3441 // for either, and the graph will fold nicely if the optimizer later reduces
3442 // the type to a constant.
3443 // The optional arguments are for specialized use by intrinsics:
3444 //  - If 'extra_slow_test' if not null is an extra condition for the slow-path.
3445 //  - If 'return_size_val', report the the total object size to the caller.
3446 //  - deoptimize_on_exception controls how Java exceptions are handled (rethrow vs deoptimize)
3447 Node* GraphKit::new_instance(Node* klass_node,
3448                              Node* extra_slow_test,
3449                              Node* *return_size_val,
3450                              bool deoptimize_on_exception) {
3451   // Compute size in doublewords
3452   // The size is always an integral number of doublewords, represented
3453   // as a positive bytewise size stored in the klass's layout_helper.
3454   // The layout_helper also encodes (in a low bit) the need for a slow path.
3455   jint  layout_con = Klass::_lh_neutral_value;
3456   Node* layout_val = get_layout_helper(klass_node, layout_con);
3457   int   layout_is_con = (layout_val == NULL);
3458 
3459   if (extra_slow_test == NULL)  extra_slow_test = intcon(0);
3460   // Generate the initial go-slow test.  It's either ALWAYS (return a
3461   // Node for 1) or NEVER (return a NULL) or perhaps (in the reflective
3462   // case) a computed value derived from the layout_helper.
3463   Node* initial_slow_test = NULL;
3464   if (layout_is_con) {
3465     assert(!StressReflectiveCode, "stress mode does not use these paths");
3466     bool must_go_slow = Klass::layout_helper_needs_slow_path(layout_con);
3467     initial_slow_test = must_go_slow ? intcon(1) : extra_slow_test;
3468   } else {   // reflective case
3469     // This reflective path is used by Unsafe.allocateInstance.
3470     // (It may be stress-tested by specifying StressReflectiveCode.)
3471     // Basically, we want to get into the VM is there's an illegal argument.
3472     Node* bit = intcon(Klass::_lh_instance_slow_path_bit);
3473     initial_slow_test = _gvn.transform( new AndINode(layout_val, bit) );
3474     if (extra_slow_test != intcon(0)) {
3475       initial_slow_test = _gvn.transform( new OrINode(initial_slow_test, extra_slow_test) );
3476     }
3477     // (Macro-expander will further convert this to a Bool, if necessary.)
3478   }
3479 
3480   // Find the size in bytes.  This is easy; it's the layout_helper.
3481   // The size value must be valid even if the slow path is taken.
3482   Node* size = NULL;
3483   if (layout_is_con) {
3484     size = MakeConX(Klass::layout_helper_size_in_bytes(layout_con));
3485   } else {   // reflective case
3486     // This reflective path is used by clone and Unsafe.allocateInstance.
3487     size = ConvI2X(layout_val);
3488 
3489     // Clear the low bits to extract layout_helper_size_in_bytes:
3490     assert((int)Klass::_lh_instance_slow_path_bit < BytesPerLong, "clear bit");
3491     Node* mask = MakeConX(~ (intptr_t)right_n_bits(LogBytesPerLong));
3492     size = _gvn.transform( new AndXNode(size, mask) );
3493   }
3494   if (return_size_val != NULL) {
3495     (*return_size_val) = size;
3496   }
3497 
3498   // This is a precise notnull oop of the klass.
3499   // (Actually, it need not be precise if this is a reflective allocation.)
3500   // It's what we cast the result to.
3501   const TypeKlassPtr* tklass = _gvn.type(klass_node)->isa_klassptr();
3502   if (!tklass)  tklass = TypeKlassPtr::OBJECT;
3503   const TypeOopPtr* oop_type = tklass->as_instance_type();
3504 
3505   // Now generate allocation code
3506 
3507   // The entire memory state is needed for slow path of the allocation
3508   // since GC and deoptimization can happened.
3509   Node *mem = reset_memory();
3510   set_all_memory(mem); // Create new memory state
3511 
3512   AllocateNode* alloc = new AllocateNode(C, AllocateNode::alloc_type(Type::TOP),
3513                                          control(), mem, i_o(),
3514                                          size, klass_node,
3515                                          initial_slow_test);
3516 
3517   return set_output_for_allocation(alloc, oop_type, deoptimize_on_exception);
3518 }
3519 
3520 //-------------------------------new_array-------------------------------------
3521 // helper for both newarray and anewarray
3522 // The 'length' parameter is (obviously) the length of the array.
3523 // See comments on new_instance for the meaning of the other arguments.
3524 Node* GraphKit::new_array(Node* klass_node,     // array klass (maybe variable)
3525                           Node* length,         // number of array elements
3526                           int   nargs,          // number of arguments to push back for uncommon trap
3527                           Node* *return_size_val,
3528                           bool deoptimize_on_exception) {
3529   jint  layout_con = Klass::_lh_neutral_value;
3530   Node* layout_val = get_layout_helper(klass_node, layout_con);
3531   int   layout_is_con = (layout_val == NULL);
3532 
3533   if (!layout_is_con && !StressReflectiveCode &&
3534       !too_many_traps(Deoptimization::Reason_class_check)) {
3535     // This is a reflective array creation site.
3536     // Optimistically assume that it is a subtype of Object[],
3537     // so that we can fold up all the address arithmetic.
3538     layout_con = Klass::array_layout_helper(T_OBJECT);
3539     Node* cmp_lh = _gvn.transform( new CmpINode(layout_val, intcon(layout_con)) );
3540     Node* bol_lh = _gvn.transform( new BoolNode(cmp_lh, BoolTest::eq) );
3541     { BuildCutout unless(this, bol_lh, PROB_MAX);
3542       inc_sp(nargs);
3543       uncommon_trap(Deoptimization::Reason_class_check,
3544                     Deoptimization::Action_maybe_recompile);
3545     }
3546     layout_val = NULL;
3547     layout_is_con = true;
3548   }
3549 
3550   // Generate the initial go-slow test.  Make sure we do not overflow
3551   // if length is huge (near 2Gig) or negative!  We do not need
3552   // exact double-words here, just a close approximation of needed
3553   // double-words.  We can't add any offset or rounding bits, lest we
3554   // take a size -1 of bytes and make it positive.  Use an unsigned
3555   // compare, so negative sizes look hugely positive.
3556   int fast_size_limit = FastAllocateSizeLimit;
3557   if (layout_is_con) {
3558     assert(!StressReflectiveCode, "stress mode does not use these paths");
3559     // Increase the size limit if we have exact knowledge of array type.
3560     int log2_esize = Klass::layout_helper_log2_element_size(layout_con);
3561     fast_size_limit <<= (LogBytesPerLong - log2_esize);
3562   }
3563 
3564   Node* initial_slow_cmp  = _gvn.transform( new CmpUNode( length, intcon( fast_size_limit ) ) );
3565   Node* initial_slow_test = _gvn.transform( new BoolNode( initial_slow_cmp, BoolTest::gt ) );
3566 
3567   // --- Size Computation ---
3568   // array_size = round_to_heap(array_header + (length << elem_shift));
3569   // where round_to_heap(x) == align_to(x, MinObjAlignmentInBytes)
3570   // and align_to(x, y) == ((x + y-1) & ~(y-1))
3571   // The rounding mask is strength-reduced, if possible.
3572   int round_mask = MinObjAlignmentInBytes - 1;
3573   Node* header_size = NULL;
3574   int   header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
3575   // (T_BYTE has the weakest alignment and size restrictions...)
3576   if (layout_is_con) {
3577     int       hsize  = Klass::layout_helper_header_size(layout_con);
3578     int       eshift = Klass::layout_helper_log2_element_size(layout_con);
3579     BasicType etype  = Klass::layout_helper_element_type(layout_con);
3580     if ((round_mask & ~right_n_bits(eshift)) == 0)
3581       round_mask = 0;  // strength-reduce it if it goes away completely
3582     assert((hsize & right_n_bits(eshift)) == 0, "hsize is pre-rounded");
3583     assert(header_size_min <= hsize, "generic minimum is smallest");
3584     header_size_min = hsize;
3585     header_size = intcon(hsize + round_mask);
3586   } else {
3587     Node* hss   = intcon(Klass::_lh_header_size_shift);
3588     Node* hsm   = intcon(Klass::_lh_header_size_mask);
3589     Node* hsize = _gvn.transform( new URShiftINode(layout_val, hss) );
3590     hsize       = _gvn.transform( new AndINode(hsize, hsm) );
3591     Node* mask  = intcon(round_mask);
3592     header_size = _gvn.transform( new AddINode(hsize, mask) );
3593   }
3594 
3595   Node* elem_shift = NULL;
3596   if (layout_is_con) {
3597     int eshift = Klass::layout_helper_log2_element_size(layout_con);
3598     if (eshift != 0)
3599       elem_shift = intcon(eshift);
3600   } else {
3601     // There is no need to mask or shift this value.
3602     // The semantics of LShiftINode include an implicit mask to 0x1F.
3603     assert(Klass::_lh_log2_element_size_shift == 0, "use shift in place");
3604     elem_shift = layout_val;
3605   }
3606 
3607   // Transition to native address size for all offset calculations:
3608   Node* lengthx = ConvI2X(length);
3609   Node* headerx = ConvI2X(header_size);
3610 #ifdef _LP64
3611   { const TypeInt* tilen = _gvn.find_int_type(length);
3612     if (tilen != NULL && tilen->_lo < 0) {
3613       // Add a manual constraint to a positive range.  Cf. array_element_address.
3614       jint size_max = fast_size_limit;
3615       if (size_max > tilen->_hi)  size_max = tilen->_hi;
3616       const TypeInt* tlcon = TypeInt::make(0, size_max, Type::WidenMin);
3617 
3618       // Only do a narrow I2L conversion if the range check passed.
3619       IfNode* iff = new IfNode(control(), initial_slow_test, PROB_MIN, COUNT_UNKNOWN);
3620       _gvn.transform(iff);
3621       RegionNode* region = new RegionNode(3);
3622       _gvn.set_type(region, Type::CONTROL);
3623       lengthx = new PhiNode(region, TypeLong::LONG);
3624       _gvn.set_type(lengthx, TypeLong::LONG);
3625 
3626       // Range check passed. Use ConvI2L node with narrow type.
3627       Node* passed = IfFalse(iff);
3628       region->init_req(1, passed);
3629       // Make I2L conversion control dependent to prevent it from
3630       // floating above the range check during loop optimizations.
3631       lengthx->init_req(1, C->constrained_convI2L(&_gvn, length, tlcon, passed));
3632 
3633       // Range check failed. Use ConvI2L with wide type because length may be invalid.
3634       region->init_req(2, IfTrue(iff));
3635       lengthx->init_req(2, ConvI2X(length));
3636 
3637       set_control(region);
3638       record_for_igvn(region);
3639       record_for_igvn(lengthx);
3640     }
3641   }
3642 #endif
3643 
3644   // Combine header size (plus rounding) and body size.  Then round down.
3645   // This computation cannot overflow, because it is used only in two
3646   // places, one where the length is sharply limited, and the other
3647   // after a successful allocation.
3648   Node* abody = lengthx;
3649   if (elem_shift != NULL)
3650     abody     = _gvn.transform( new LShiftXNode(lengthx, elem_shift) );
3651   Node* size  = _gvn.transform( new AddXNode(headerx, abody) );
3652   if (round_mask != 0) {
3653     Node* mask = MakeConX(~round_mask);
3654     size       = _gvn.transform( new AndXNode(size, mask) );
3655   }
3656   // else if round_mask == 0, the size computation is self-rounding
3657 
3658   if (return_size_val != NULL) {
3659     // This is the size
3660     (*return_size_val) = size;
3661   }
3662 
3663   // Now generate allocation code
3664 
3665   // The entire memory state is needed for slow path of the allocation
3666   // since GC and deoptimization can happened.
3667   Node *mem = reset_memory();
3668   set_all_memory(mem); // Create new memory state
3669 
3670   if (initial_slow_test->is_Bool()) {
3671     // Hide it behind a CMoveI, or else PhaseIdealLoop::split_up will get sick.
3672     initial_slow_test = initial_slow_test->as_Bool()->as_int_value(&_gvn);
3673   }
3674 
3675   // Create the AllocateArrayNode and its result projections
3676   AllocateArrayNode* alloc
3677     = new AllocateArrayNode(C, AllocateArrayNode::alloc_type(TypeInt::INT),
3678                             control(), mem, i_o(),
3679                             size, klass_node,
3680                             initial_slow_test,
3681                             length);
3682 
3683   // Cast to correct type.  Note that the klass_node may be constant or not,
3684   // and in the latter case the actual array type will be inexact also.
3685   // (This happens via a non-constant argument to inline_native_newArray.)
3686   // In any case, the value of klass_node provides the desired array type.
3687   const TypeInt* length_type = _gvn.find_int_type(length);
3688   const TypeOopPtr* ary_type = _gvn.type(klass_node)->is_klassptr()->as_instance_type();
3689   if (ary_type->isa_aryptr() && length_type != NULL) {
3690     // Try to get a better type than POS for the size
3691     ary_type = ary_type->is_aryptr()->cast_to_size(length_type);
3692   }
3693 
3694   Node* javaoop = set_output_for_allocation(alloc, ary_type, deoptimize_on_exception);
3695 
3696   // Cast length on remaining path to be as narrow as possible
3697   if (map()->find_edge(length) >= 0) {
3698     Node* ccast = alloc->make_ideal_length(ary_type, &_gvn);
3699     if (ccast != length) {
3700       _gvn.set_type_bottom(ccast);
3701       record_for_igvn(ccast);
3702       replace_in_map(length, ccast);
3703     }
3704   }
3705 
3706   return javaoop;
3707 }
3708 
3709 // The following "Ideal_foo" functions are placed here because they recognize
3710 // the graph shapes created by the functions immediately above.
3711 
3712 //---------------------------Ideal_allocation----------------------------------
3713 // Given an oop pointer or raw pointer, see if it feeds from an AllocateNode.
3714 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase) {
3715   if (ptr == NULL) {     // reduce dumb test in callers
3716     return NULL;
3717   }
3718   if (ptr->is_CheckCastPP()) { // strip only one raw-to-oop cast
3719     ptr = ptr->in(1);
3720     if (ptr == NULL) return NULL;
3721   }
3722   // Return NULL for allocations with several casts:
3723   //   j.l.reflect.Array.newInstance(jobject, jint)
3724   //   Object.clone()
3725   // to keep more precise type from last cast.
3726   if (ptr->is_Proj()) {
3727     Node* allo = ptr->in(0);
3728     if (allo != NULL && allo->is_Allocate()) {
3729       return allo->as_Allocate();
3730     }
3731   }
3732   // Report failure to match.
3733   return NULL;
3734 }
3735 
3736 // Fancy version which also strips off an offset (and reports it to caller).
3737 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase,
3738                                              intptr_t& offset) {
3739   Node* base = AddPNode::Ideal_base_and_offset(ptr, phase, offset);
3740   if (base == NULL)  return NULL;
3741   return Ideal_allocation(base, phase);
3742 }
3743 
3744 // Trace Initialize <- Proj[Parm] <- Allocate
3745 AllocateNode* InitializeNode::allocation() {
3746   Node* rawoop = in(InitializeNode::RawAddress);
3747   if (rawoop->is_Proj()) {
3748     Node* alloc = rawoop->in(0);
3749     if (alloc->is_Allocate()) {
3750       return alloc->as_Allocate();
3751     }
3752   }
3753   return NULL;
3754 }
3755 
3756 // Trace Allocate -> Proj[Parm] -> Initialize
3757 InitializeNode* AllocateNode::initialization() {
3758   ProjNode* rawoop = proj_out_or_null(AllocateNode::RawAddress);
3759   if (rawoop == NULL)  return NULL;
3760   for (DUIterator_Fast imax, i = rawoop->fast_outs(imax); i < imax; i++) {
3761     Node* init = rawoop->fast_out(i);
3762     if (init->is_Initialize()) {
3763       assert(init->as_Initialize()->allocation() == this, "2-way link");
3764       return init->as_Initialize();
3765     }
3766   }
3767   return NULL;
3768 }
3769 
3770 //----------------------------- loop predicates ---------------------------
3771 
3772 //------------------------------add_predicate_impl----------------------------
3773 void GraphKit::add_predicate_impl(Deoptimization::DeoptReason reason, int nargs) {
3774   // Too many traps seen?
3775   if (too_many_traps(reason)) {
3776 #ifdef ASSERT
3777     if (TraceLoopPredicate) {
3778       int tc = C->trap_count(reason);
3779       tty->print("too many traps=%s tcount=%d in ",
3780                     Deoptimization::trap_reason_name(reason), tc);
3781       method()->print(); // which method has too many predicate traps
3782       tty->cr();
3783     }
3784 #endif
3785     // We cannot afford to take more traps here,
3786     // do not generate predicate.
3787     return;
3788   }
3789 
3790   Node *cont    = _gvn.intcon(1);
3791   Node* opq     = _gvn.transform(new Opaque1Node(C, cont));
3792   Node *bol     = _gvn.transform(new Conv2BNode(opq));
3793   IfNode* iff   = create_and_map_if(control(), bol, PROB_MAX, COUNT_UNKNOWN);
3794   Node* iffalse = _gvn.transform(new IfFalseNode(iff));
3795   C->add_predicate_opaq(opq);
3796   {
3797     PreserveJVMState pjvms(this);
3798     set_control(iffalse);
3799     inc_sp(nargs);
3800     uncommon_trap(reason, Deoptimization::Action_maybe_recompile);
3801   }
3802   Node* iftrue = _gvn.transform(new IfTrueNode(iff));
3803   set_control(iftrue);
3804 }
3805 
3806 //------------------------------add_predicate---------------------------------
3807 void GraphKit::add_predicate(int nargs) {
3808   if (UseLoopPredicate) {
3809     add_predicate_impl(Deoptimization::Reason_predicate, nargs);
3810   }
3811   // loop's limit check predicate should be near the loop.
3812   add_predicate_impl(Deoptimization::Reason_loop_limit_check, nargs);
3813 }
3814 
3815 //----------------------------- store barriers ----------------------------
3816 #define __ ideal.
3817 
3818 void GraphKit::sync_kit(IdealKit& ideal) {
3819   set_all_memory(__ merged_memory());
3820   set_i_o(__ i_o());
3821   set_control(__ ctrl());
3822 }
3823 
3824 void GraphKit::final_sync(IdealKit& ideal) {
3825   // Final sync IdealKit and graphKit.
3826   sync_kit(ideal);
3827 }
3828 
3829 Node* GraphKit::byte_map_base_node() {
3830   // Get base of card map
3831   CardTableModRefBS* ct =
3832     barrier_set_cast<CardTableModRefBS>(Universe::heap()->barrier_set());
3833   assert(sizeof(*ct->byte_map_base) == sizeof(jbyte), "adjust users of this code");
3834   if (ct->byte_map_base != NULL) {
3835     return makecon(TypeRawPtr::make((address)ct->byte_map_base));
3836   } else {
3837     return null();
3838   }
3839 }
3840 
3841 // vanilla/CMS post barrier
3842 // Insert a write-barrier store.  This is to let generational GC work; we have
3843 // to flag all oop-stores before the next GC point.
3844 void GraphKit::write_barrier_post(Node* oop_store,
3845                                   Node* obj,
3846                                   Node* adr,
3847                                   uint  adr_idx,
3848                                   Node* val,
3849                                   bool use_precise) {
3850   // No store check needed if we're storing a NULL or an old object
3851   // (latter case is probably a string constant). The concurrent
3852   // mark sweep garbage collector, however, needs to have all nonNull
3853   // oop updates flagged via card-marks.
3854   if (val != NULL && val->is_Con()) {
3855     // must be either an oop or NULL
3856     const Type* t = val->bottom_type();
3857     if (t == TypePtr::NULL_PTR || t == Type::TOP)
3858       // stores of null never (?) need barriers
3859       return;
3860   }
3861 
3862   if (use_ReduceInitialCardMarks()
3863       && obj == just_allocated_object(control())) {
3864     // We can skip marks on a freshly-allocated object in Eden.
3865     // Keep this code in sync with new_store_pre_barrier() in runtime.cpp.
3866     // That routine informs GC to take appropriate compensating steps,
3867     // upon a slow-path allocation, so as to make this card-mark
3868     // elision safe.
3869     return;
3870   }
3871 
3872   if (!use_precise) {
3873     // All card marks for a (non-array) instance are in one place:
3874     adr = obj;
3875   }
3876   // (Else it's an array (or unknown), and we want more precise card marks.)
3877   assert(adr != NULL, "");
3878 
3879   IdealKit ideal(this, true);
3880 
3881   // Convert the pointer to an int prior to doing math on it
3882   Node* cast = __ CastPX(__ ctrl(), adr);
3883 
3884   // Divide by card size
3885   assert(Universe::heap()->barrier_set()->is_a(BarrierSet::CardTableModRef),
3886          "Only one we handle so far.");
3887   Node* card_offset = __ URShiftX( cast, __ ConI(CardTableModRefBS::card_shift) );
3888 
3889   // Combine card table base and card offset
3890   Node* card_adr = __ AddP(__ top(), byte_map_base_node(), card_offset );
3891 
3892   // Get the alias_index for raw card-mark memory
3893   int adr_type = Compile::AliasIdxRaw;
3894   Node*   zero = __ ConI(0); // Dirty card value
3895   BasicType bt = T_BYTE;
3896 
3897   if (UseConcMarkSweepGC && UseCondCardMark) {
3898     insert_mem_bar(Op_MemBarVolatile);   // StoreLoad barrier
3899     __ sync_kit(this);
3900   }
3901 
3902   if (UseCondCardMark) {
3903     // The classic GC reference write barrier is typically implemented
3904     // as a store into the global card mark table.  Unfortunately
3905     // unconditional stores can result in false sharing and excessive
3906     // coherence traffic as well as false transactional aborts.
3907     // UseCondCardMark enables MP "polite" conditional card mark
3908     // stores.  In theory we could relax the load from ctrl() to
3909     // no_ctrl, but that doesn't buy much latitude.
3910     Node* card_val = __ load( __ ctrl(), card_adr, TypeInt::BYTE, bt, adr_type);
3911     __ if_then(card_val, BoolTest::ne, zero);
3912   }
3913 
3914   // Smash zero into card
3915   if( !UseConcMarkSweepGC ) {
3916     __ store(__ ctrl(), card_adr, zero, bt, adr_type, MemNode::unordered);
3917   } else {
3918     // Specialized path for CM store barrier
3919     __ storeCM(__ ctrl(), card_adr, zero, oop_store, adr_idx, bt, adr_type);
3920   }
3921 
3922   if (UseCondCardMark) {
3923     __ end_if();
3924   }
3925 
3926   // Final sync IdealKit and GraphKit.
3927   final_sync(ideal);
3928 }
3929 /*
3930  * Determine if the G1 pre-barrier can be removed. The pre-barrier is
3931  * required by SATB to make sure all objects live at the start of the
3932  * marking are kept alive, all reference updates need to any previous
3933  * reference stored before writing.
3934  *
3935  * If the previous value is NULL there is no need to save the old value.
3936  * References that are NULL are filtered during runtime by the barrier
3937  * code to avoid unnecessary queuing.
3938  *
3939  * However in the case of newly allocated objects it might be possible to
3940  * prove that the reference about to be overwritten is NULL during compile
3941  * time and avoid adding the barrier code completely.
3942  *
3943  * The compiler needs to determine that the object in which a field is about
3944  * to be written is newly allocated, and that no prior store to the same field
3945  * has happened since the allocation.
3946  *
3947  * Returns true if the pre-barrier can be removed
3948  */
3949 bool GraphKit::g1_can_remove_pre_barrier(PhaseTransform* phase, Node* adr,
3950                                          BasicType bt, uint adr_idx) {
3951   intptr_t offset = 0;
3952   Node* base = AddPNode::Ideal_base_and_offset(adr, phase, offset);
3953   AllocateNode* alloc = AllocateNode::Ideal_allocation(base, phase);
3954 
3955   if (offset == Type::OffsetBot) {
3956     return false; // cannot unalias unless there are precise offsets
3957   }
3958 
3959   if (alloc == NULL) {
3960     return false; // No allocation found
3961   }
3962 
3963   intptr_t size_in_bytes = type2aelembytes(bt);
3964 
3965   Node* mem = memory(adr_idx); // start searching here...
3966 
3967   for (int cnt = 0; cnt < 50; cnt++) {
3968 
3969     if (mem->is_Store()) {
3970 
3971       Node* st_adr = mem->in(MemNode::Address);
3972       intptr_t st_offset = 0;
3973       Node* st_base = AddPNode::Ideal_base_and_offset(st_adr, phase, st_offset);
3974 
3975       if (st_base == NULL) {
3976         break; // inscrutable pointer
3977       }
3978 
3979       // Break we have found a store with same base and offset as ours so break
3980       if (st_base == base && st_offset == offset) {
3981         break;
3982       }
3983 
3984       if (st_offset != offset && st_offset != Type::OffsetBot) {
3985         const int MAX_STORE = BytesPerLong;
3986         if (st_offset >= offset + size_in_bytes ||
3987             st_offset <= offset - MAX_STORE ||
3988             st_offset <= offset - mem->as_Store()->memory_size()) {
3989           // Success:  The offsets are provably independent.
3990           // (You may ask, why not just test st_offset != offset and be done?
3991           // The answer is that stores of different sizes can co-exist
3992           // in the same sequence of RawMem effects.  We sometimes initialize
3993           // a whole 'tile' of array elements with a single jint or jlong.)
3994           mem = mem->in(MemNode::Memory);
3995           continue; // advance through independent store memory
3996         }
3997       }
3998 
3999       if (st_base != base
4000           && MemNode::detect_ptr_independence(base, alloc, st_base,
4001                                               AllocateNode::Ideal_allocation(st_base, phase),
4002                                               phase)) {
4003         // Success:  The bases are provably independent.
4004         mem = mem->in(MemNode::Memory);
4005         continue; // advance through independent store memory
4006       }
4007     } else if (mem->is_Proj() && mem->in(0)->is_Initialize()) {
4008 
4009       InitializeNode* st_init = mem->in(0)->as_Initialize();
4010       AllocateNode* st_alloc = st_init->allocation();
4011 
4012       // Make sure that we are looking at the same allocation site.
4013       // The alloc variable is guaranteed to not be null here from earlier check.
4014       if (alloc == st_alloc) {
4015         // Check that the initialization is storing NULL so that no previous store
4016         // has been moved up and directly write a reference
4017         Node* captured_store = st_init->find_captured_store(offset,
4018                                                             type2aelembytes(T_OBJECT),
4019                                                             phase);
4020         if (captured_store == NULL || captured_store == st_init->zero_memory()) {
4021           return true;
4022         }
4023       }
4024     }
4025 
4026     // Unless there is an explicit 'continue', we must bail out here,
4027     // because 'mem' is an inscrutable memory state (e.g., a call).
4028     break;
4029   }
4030 
4031   return false;
4032 }
4033 
4034 // G1 pre/post barriers
4035 void GraphKit::g1_write_barrier_pre(bool do_load,
4036                                     Node* obj,
4037                                     Node* adr,
4038                                     uint alias_idx,
4039                                     Node* val,
4040                                     const TypeOopPtr* val_type,
4041                                     Node* pre_val,
4042                                     BasicType bt) {
4043 
4044   // Some sanity checks
4045   // Note: val is unused in this routine.
4046 
4047   if (do_load) {
4048     // We need to generate the load of the previous value
4049     assert(obj != NULL, "must have a base");
4050     assert(adr != NULL, "where are loading from?");
4051     assert(pre_val == NULL, "loaded already?");
4052     assert(val_type != NULL, "need a type");
4053 
4054     if (use_ReduceInitialCardMarks()
4055         && g1_can_remove_pre_barrier(&_gvn, adr, bt, alias_idx)) {
4056       return;
4057     }
4058 
4059   } else {
4060     // In this case both val_type and alias_idx are unused.
4061     assert(pre_val != NULL, "must be loaded already");
4062     // Nothing to be done if pre_val is null.
4063     if (pre_val->bottom_type() == TypePtr::NULL_PTR) return;
4064     assert(pre_val->bottom_type()->basic_type() == T_OBJECT, "or we shouldn't be here");
4065   }
4066   assert(bt == T_OBJECT, "or we shouldn't be here");
4067 
4068   IdealKit ideal(this, true);
4069 
4070   Node* tls = __ thread(); // ThreadLocalStorage
4071 
4072   Node* no_ctrl = NULL;
4073   Node* no_base = __ top();
4074   Node* zero  = __ ConI(0);
4075   Node* zeroX = __ ConX(0);
4076 
4077   float likely  = PROB_LIKELY(0.999);
4078   float unlikely  = PROB_UNLIKELY(0.999);
4079 
4080   BasicType active_type = in_bytes(SATBMarkQueue::byte_width_of_active()) == 4 ? T_INT : T_BYTE;
4081   assert(in_bytes(SATBMarkQueue::byte_width_of_active()) == 4 || in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "flag width");
4082 
4083   // Offsets into the thread
4084   const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() +  // 648
4085                                           SATBMarkQueue::byte_offset_of_active());
4086   const int index_offset   = in_bytes(JavaThread::satb_mark_queue_offset() +  // 656
4087                                           SATBMarkQueue::byte_offset_of_index());
4088   const int buffer_offset  = in_bytes(JavaThread::satb_mark_queue_offset() +  // 652
4089                                           SATBMarkQueue::byte_offset_of_buf());
4090 
4091   // Now the actual pointers into the thread
4092   Node* marking_adr = __ AddP(no_base, tls, __ ConX(marking_offset));
4093   Node* buffer_adr  = __ AddP(no_base, tls, __ ConX(buffer_offset));
4094   Node* index_adr   = __ AddP(no_base, tls, __ ConX(index_offset));
4095 
4096   // Now some of the values
4097   Node* marking = __ load(__ ctrl(), marking_adr, TypeInt::INT, active_type, Compile::AliasIdxRaw);
4098 
4099   // if (!marking)
4100   __ if_then(marking, BoolTest::ne, zero, unlikely); {
4101     BasicType index_bt = TypeX_X->basic_type();
4102     assert(sizeof(size_t) == type2aelembytes(index_bt), "Loading G1 SATBMarkQueue::_index with wrong size.");
4103     Node* index   = __ load(__ ctrl(), index_adr, TypeX_X, index_bt, Compile::AliasIdxRaw);
4104 
4105     if (do_load) {
4106       // load original value
4107       // alias_idx correct??
4108       pre_val = __ load(__ ctrl(), adr, val_type, bt, alias_idx);
4109     }
4110 
4111     // if (pre_val != NULL)
4112     __ if_then(pre_val, BoolTest::ne, null()); {
4113       Node* buffer  = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
4114 
4115       // is the queue for this thread full?
4116       __ if_then(index, BoolTest::ne, zeroX, likely); {
4117 
4118         // decrement the index
4119         Node* next_index = _gvn.transform(new SubXNode(index, __ ConX(sizeof(intptr_t))));
4120 
4121         // Now get the buffer location we will log the previous value into and store it
4122         Node *log_addr = __ AddP(no_base, buffer, next_index);
4123         __ store(__ ctrl(), log_addr, pre_val, T_OBJECT, Compile::AliasIdxRaw, MemNode::unordered);
4124         // update the index
4125         __ store(__ ctrl(), index_adr, next_index, index_bt, Compile::AliasIdxRaw, MemNode::unordered);
4126 
4127       } __ else_(); {
4128 
4129         // logging buffer is full, call the runtime
4130         const TypeFunc *tf = OptoRuntime::g1_wb_pre_Type();
4131         __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_pre), "g1_wb_pre", pre_val, tls);
4132       } __ end_if();  // (!index)
4133     } __ end_if();  // (pre_val != NULL)
4134   } __ end_if();  // (!marking)
4135 
4136   // Final sync IdealKit and GraphKit.
4137   final_sync(ideal);
4138 }
4139 
4140 /*
4141  * G1 similar to any GC with a Young Generation requires a way to keep track of
4142  * references from Old Generation to Young Generation to make sure all live
4143  * objects are found. G1 also requires to keep track of object references
4144  * between different regions to enable evacuation of old regions, which is done
4145  * as part of mixed collections. References are tracked in remembered sets and
4146  * is continuously updated as reference are written to with the help of the
4147  * post-barrier.
4148  *
4149  * To reduce the number of updates to the remembered set the post-barrier
4150  * filters updates to fields in objects located in the Young Generation,
4151  * the same region as the reference, when the NULL is being written or
4152  * if the card is already marked as dirty by an earlier write.
4153  *
4154  * Under certain circumstances it is possible to avoid generating the
4155  * post-barrier completely if it is possible during compile time to prove
4156  * the object is newly allocated and that no safepoint exists between the
4157  * allocation and the store.
4158  *
4159  * In the case of slow allocation the allocation code must handle the barrier
4160  * as part of the allocation in the case the allocated object is not located
4161  * in the nursery, this would happen for humongous objects. This is similar to
4162  * how CMS is required to handle this case, see the comments for the method
4163  * CollectedHeap::new_store_pre_barrier and OptoRuntime::new_store_pre_barrier.
4164  * A deferred card mark is required for these objects and handled in the above
4165  * mentioned methods.
4166  *
4167  * Returns true if the post barrier can be removed
4168  */
4169 bool GraphKit::g1_can_remove_post_barrier(PhaseTransform* phase, Node* store,
4170                                           Node* adr) {
4171   intptr_t      offset = 0;
4172   Node*         base   = AddPNode::Ideal_base_and_offset(adr, phase, offset);
4173   AllocateNode* alloc  = AllocateNode::Ideal_allocation(base, phase);
4174 
4175   if (offset == Type::OffsetBot) {
4176     return false; // cannot unalias unless there are precise offsets
4177   }
4178 
4179   if (alloc == NULL) {
4180      return false; // No allocation found
4181   }
4182 
4183   // Start search from Store node
4184   Node* mem = store->in(MemNode::Control);
4185   if (mem->is_Proj() && mem->in(0)->is_Initialize()) {
4186 
4187     InitializeNode* st_init = mem->in(0)->as_Initialize();
4188     AllocateNode*  st_alloc = st_init->allocation();
4189 
4190     // Make sure we are looking at the same allocation
4191     if (alloc == st_alloc) {
4192       return true;
4193     }
4194   }
4195 
4196   return false;
4197 }
4198 
4199 //
4200 // Update the card table and add card address to the queue
4201 //
4202 void GraphKit::g1_mark_card(IdealKit& ideal,
4203                             Node* card_adr,
4204                             Node* oop_store,
4205                             uint oop_alias_idx,
4206                             Node* index,
4207                             Node* index_adr,
4208                             Node* buffer,
4209                             const TypeFunc* tf) {
4210 
4211   Node* zero  = __ ConI(0);
4212   Node* zeroX = __ ConX(0);
4213   Node* no_base = __ top();
4214   BasicType card_bt = T_BYTE;
4215   // Smash zero into card. MUST BE ORDERED WRT TO STORE
4216   __ storeCM(__ ctrl(), card_adr, zero, oop_store, oop_alias_idx, card_bt, Compile::AliasIdxRaw);
4217 
4218   //  Now do the queue work
4219   __ if_then(index, BoolTest::ne, zeroX); {
4220 
4221     Node* next_index = _gvn.transform(new SubXNode(index, __ ConX(sizeof(intptr_t))));
4222     Node* log_addr = __ AddP(no_base, buffer, next_index);
4223 
4224     // Order, see storeCM.
4225     __ store(__ ctrl(), log_addr, card_adr, T_ADDRESS, Compile::AliasIdxRaw, MemNode::unordered);
4226     __ store(__ ctrl(), index_adr, next_index, TypeX_X->basic_type(), Compile::AliasIdxRaw, MemNode::unordered);
4227 
4228   } __ else_(); {
4229     __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_post), "g1_wb_post", card_adr, __ thread());
4230   } __ end_if();
4231 
4232 }
4233 
4234 void GraphKit::g1_write_barrier_post(Node* oop_store,
4235                                      Node* obj,
4236                                      Node* adr,
4237                                      uint alias_idx,
4238                                      Node* val,
4239                                      BasicType bt,
4240                                      bool use_precise) {
4241   // If we are writing a NULL then we need no post barrier
4242 
4243   if (val != NULL && val->is_Con() && val->bottom_type() == TypePtr::NULL_PTR) {
4244     // Must be NULL
4245     const Type* t = val->bottom_type();
4246     assert(t == Type::TOP || t == TypePtr::NULL_PTR, "must be NULL");
4247     // No post barrier if writing NULLx
4248     return;
4249   }
4250 
4251   if (use_ReduceInitialCardMarks() && obj == just_allocated_object(control())) {
4252     // We can skip marks on a freshly-allocated object in Eden.
4253     // Keep this code in sync with new_store_pre_barrier() in runtime.cpp.
4254     // That routine informs GC to take appropriate compensating steps,
4255     // upon a slow-path allocation, so as to make this card-mark
4256     // elision safe.
4257     return;
4258   }
4259 
4260   if (use_ReduceInitialCardMarks()
4261       && g1_can_remove_post_barrier(&_gvn, oop_store, adr)) {
4262     return;
4263   }
4264 
4265   if (!use_precise) {
4266     // All card marks for a (non-array) instance are in one place:
4267     adr = obj;
4268   }
4269   // (Else it's an array (or unknown), and we want more precise card marks.)
4270   assert(adr != NULL, "");
4271 
4272   IdealKit ideal(this, true);
4273 
4274   Node* tls = __ thread(); // ThreadLocalStorage
4275 
4276   Node* no_base = __ top();
4277   float likely  = PROB_LIKELY(0.999);
4278   float unlikely  = PROB_UNLIKELY(0.999);
4279   Node* young_card = __ ConI((jint)G1SATBCardTableModRefBS::g1_young_card_val());
4280   Node* dirty_card = __ ConI((jint)CardTableModRefBS::dirty_card_val());
4281   Node* zeroX = __ ConX(0);
4282 
4283   // Get the alias_index for raw card-mark memory
4284   const TypePtr* card_type = TypeRawPtr::BOTTOM;
4285 
4286   const TypeFunc *tf = OptoRuntime::g1_wb_post_Type();
4287 
4288   // Offsets into the thread
4289   const int index_offset  = in_bytes(JavaThread::dirty_card_queue_offset() +
4290                                      DirtyCardQueue::byte_offset_of_index());
4291   const int buffer_offset = in_bytes(JavaThread::dirty_card_queue_offset() +
4292                                      DirtyCardQueue::byte_offset_of_buf());
4293 
4294   // Pointers into the thread
4295 
4296   Node* buffer_adr = __ AddP(no_base, tls, __ ConX(buffer_offset));
4297   Node* index_adr =  __ AddP(no_base, tls, __ ConX(index_offset));
4298 
4299   // Now some values
4300   // Use ctrl to avoid hoisting these values past a safepoint, which could
4301   // potentially reset these fields in the JavaThread.
4302   Node* index  = __ load(__ ctrl(), index_adr, TypeX_X, TypeX_X->basic_type(), Compile::AliasIdxRaw);
4303   Node* buffer = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
4304 
4305   // Convert the store obj pointer to an int prior to doing math on it
4306   // Must use ctrl to prevent "integerized oop" existing across safepoint
4307   Node* cast =  __ CastPX(__ ctrl(), adr);
4308 
4309   // Divide pointer by card size
4310   Node* card_offset = __ URShiftX( cast, __ ConI(CardTableModRefBS::card_shift) );
4311 
4312   // Combine card table base and card offset
4313   Node* card_adr = __ AddP(no_base, byte_map_base_node(), card_offset );
4314 
4315   // If we know the value being stored does it cross regions?
4316 
4317   if (val != NULL) {
4318     // Does the store cause us to cross regions?
4319 
4320     // Should be able to do an unsigned compare of region_size instead of
4321     // and extra shift. Do we have an unsigned compare??
4322     // Node* region_size = __ ConI(1 << HeapRegion::LogOfHRGrainBytes);
4323     Node* xor_res =  __ URShiftX ( __ XorX( cast,  __ CastPX(__ ctrl(), val)), __ ConI(HeapRegion::LogOfHRGrainBytes));
4324 
4325     // if (xor_res == 0) same region so skip
4326     __ if_then(xor_res, BoolTest::ne, zeroX); {
4327 
4328       // No barrier if we are storing a NULL
4329       __ if_then(val, BoolTest::ne, null(), unlikely); {
4330 
4331         // Ok must mark the card if not already dirty
4332 
4333         // load the original value of the card
4334         Node* card_val = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
4335 
4336         __ if_then(card_val, BoolTest::ne, young_card); {
4337           sync_kit(ideal);
4338           // Use Op_MemBarVolatile to achieve the effect of a StoreLoad barrier.
4339           insert_mem_bar(Op_MemBarVolatile, oop_store);
4340           __ sync_kit(this);
4341 
4342           Node* card_val_reload = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
4343           __ if_then(card_val_reload, BoolTest::ne, dirty_card); {
4344             g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
4345           } __ end_if();
4346         } __ end_if();
4347       } __ end_if();
4348     } __ end_if();
4349   } else {
4350     // The Object.clone() intrinsic uses this path if !ReduceInitialCardMarks.
4351     // We don't need a barrier here if the destination is a newly allocated object
4352     // in Eden. Otherwise, GC verification breaks because we assume that cards in Eden
4353     // are set to 'g1_young_gen' (see G1SATBCardTableModRefBS::verify_g1_young_region()).
4354     assert(!use_ReduceInitialCardMarks(), "can only happen with card marking");
4355     Node* card_val = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
4356     __ if_then(card_val, BoolTest::ne, young_card); {
4357       g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
4358     } __ end_if();
4359   }
4360 
4361   // Final sync IdealKit and GraphKit.
4362   final_sync(ideal);
4363 }
4364 #undef __
4365 
4366 
4367 Node* GraphKit::load_String_length(Node* ctrl, Node* str) {
4368   Node* len = load_array_length(load_String_value(ctrl, str));
4369   Node* coder = load_String_coder(ctrl, str);
4370   // Divide length by 2 if coder is UTF16
4371   return _gvn.transform(new RShiftINode(len, coder));
4372 }
4373 
4374 Node* GraphKit::load_String_value(Node* ctrl, Node* str) {
4375   int value_offset = java_lang_String::value_offset_in_bytes();
4376   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4377                                                      false, NULL, 0);
4378   const TypePtr* value_field_type = string_type->add_offset(value_offset);
4379   const TypeAryPtr* value_type = TypeAryPtr::make(TypePtr::NotNull,
4380                                                   TypeAry::make(TypeInt::BYTE, TypeInt::POS),
4381                                                   ciTypeArrayKlass::make(T_BYTE), true, 0);
4382   int value_field_idx = C->get_alias_index(value_field_type);
4383   Node* load = make_load(ctrl, basic_plus_adr(str, str, value_offset),
4384                          value_type, T_OBJECT, value_field_idx, MemNode::unordered);
4385   // String.value field is known to be @Stable.
4386   if (UseImplicitStableValues) {
4387     load = cast_array_to_stable(load, value_type);
4388   }
4389   return load;
4390 }
4391 
4392 Node* GraphKit::load_String_coder(Node* ctrl, Node* str) {
4393   if (!CompactStrings) {
4394     return intcon(java_lang_String::CODER_UTF16);
4395   }
4396   int coder_offset = java_lang_String::coder_offset_in_bytes();
4397   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4398                                                      false, NULL, 0);
4399   const TypePtr* coder_field_type = string_type->add_offset(coder_offset);
4400   int coder_field_idx = C->get_alias_index(coder_field_type);
4401   return make_load(ctrl, basic_plus_adr(str, str, coder_offset),
4402                    TypeInt::BYTE, T_BYTE, coder_field_idx, MemNode::unordered);
4403 }
4404 
4405 void GraphKit::store_String_value(Node* ctrl, Node* str, Node* value) {
4406   int value_offset = java_lang_String::value_offset_in_bytes();
4407   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4408                                                      false, NULL, 0);
4409   const TypePtr* value_field_type = string_type->add_offset(value_offset);
4410   store_oop_to_object(ctrl, str,  basic_plus_adr(str, value_offset), value_field_type,
4411       value, TypeAryPtr::BYTES, T_OBJECT, MemNode::unordered);
4412 }
4413 
4414 void GraphKit::store_String_coder(Node* ctrl, Node* str, Node* value) {
4415   int coder_offset = java_lang_String::coder_offset_in_bytes();
4416   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4417                                                      false, NULL, 0);
4418   const TypePtr* coder_field_type = string_type->add_offset(coder_offset);
4419   int coder_field_idx = C->get_alias_index(coder_field_type);
4420   store_to_memory(ctrl, basic_plus_adr(str, coder_offset),
4421                   value, T_BYTE, coder_field_idx, MemNode::unordered);
4422 }
4423 
4424 // Capture src and dst memory state with a MergeMemNode
4425 Node* GraphKit::capture_memory(const TypePtr* src_type, const TypePtr* dst_type) {
4426   if (src_type == dst_type) {
4427     // Types are equal, we don't need a MergeMemNode
4428     return memory(src_type);
4429   }
4430   MergeMemNode* merge = MergeMemNode::make(map()->memory());
4431   record_for_igvn(merge); // fold it up later, if possible
4432   int src_idx = C->get_alias_index(src_type);
4433   int dst_idx = C->get_alias_index(dst_type);
4434   merge->set_memory_at(src_idx, memory(src_idx));
4435   merge->set_memory_at(dst_idx, memory(dst_idx));
4436   return merge;
4437 }
4438 
4439 Node* GraphKit::compress_string(Node* src, const TypeAryPtr* src_type, Node* dst, Node* count) {
4440   assert(Matcher::match_rule_supported(Op_StrCompressedCopy), "Intrinsic not supported");
4441   assert(src_type == TypeAryPtr::BYTES || src_type == TypeAryPtr::CHARS, "invalid source type");
4442   // If input and output memory types differ, capture both states to preserve
4443   // the dependency between preceding and subsequent loads/stores.
4444   // For example, the following program:
4445   //  StoreB
4446   //  compress_string
4447   //  LoadB
4448   // has this memory graph (use->def):
4449   //  LoadB -> compress_string -> CharMem
4450   //             ... -> StoreB -> ByteMem
4451   // The intrinsic hides the dependency between LoadB and StoreB, causing
4452   // the load to read from memory not containing the result of the StoreB.
4453   // The correct memory graph should look like this:
4454   //  LoadB -> compress_string -> MergeMem(CharMem, StoreB(ByteMem))
4455   Node* mem = capture_memory(src_type, TypeAryPtr::BYTES);
4456   StrCompressedCopyNode* str = new StrCompressedCopyNode(control(), mem, src, dst, count);
4457   Node* res_mem = _gvn.transform(new SCMemProjNode(str));
4458   set_memory(res_mem, TypeAryPtr::BYTES);
4459   return str;
4460 }
4461 
4462 void GraphKit::inflate_string(Node* src, Node* dst, const TypeAryPtr* dst_type, Node* count) {
4463   assert(Matcher::match_rule_supported(Op_StrInflatedCopy), "Intrinsic not supported");
4464   assert(dst_type == TypeAryPtr::BYTES || dst_type == TypeAryPtr::CHARS, "invalid dest type");
4465   // Capture src and dst memory (see comment in 'compress_string').
4466   Node* mem = capture_memory(TypeAryPtr::BYTES, dst_type);
4467   StrInflatedCopyNode* str = new StrInflatedCopyNode(control(), mem, src, dst, count);
4468   set_memory(_gvn.transform(str), dst_type);
4469 }
4470 
4471 void GraphKit::inflate_string_slow(Node* src, Node* dst, Node* start, Node* count) {
4472   /**
4473    * int i_char = start;
4474    * for (int i_byte = 0; i_byte < count; i_byte++) {
4475    *   dst[i_char++] = (char)(src[i_byte] & 0xff);
4476    * }
4477    */
4478   add_predicate();
4479   RegionNode* head = new RegionNode(3);
4480   head->init_req(1, control());
4481   gvn().set_type(head, Type::CONTROL);
4482   record_for_igvn(head);
4483 
4484   Node* i_byte = new PhiNode(head, TypeInt::INT);
4485   i_byte->init_req(1, intcon(0));
4486   gvn().set_type(i_byte, TypeInt::INT);
4487   record_for_igvn(i_byte);
4488 
4489   Node* i_char = new PhiNode(head, TypeInt::INT);
4490   i_char->init_req(1, start);
4491   gvn().set_type(i_char, TypeInt::INT);
4492   record_for_igvn(i_char);
4493 
4494   Node* mem = PhiNode::make(head, memory(TypeAryPtr::BYTES), Type::MEMORY, TypeAryPtr::BYTES);
4495   gvn().set_type(mem, Type::MEMORY);
4496   record_for_igvn(mem);
4497   set_control(head);
4498   set_memory(mem, TypeAryPtr::BYTES);
4499   Node* ch = load_array_element(control(), src, i_byte, TypeAryPtr::BYTES);
4500   Node* st = store_to_memory(control(), array_element_address(dst, i_char, T_BYTE),
4501                              AndI(ch, intcon(0xff)), T_CHAR, TypeAryPtr::BYTES, MemNode::unordered,
4502                              false, false, true /* mismatched */);
4503 
4504   IfNode* iff = create_and_map_if(head, Bool(CmpI(i_byte, count), BoolTest::lt), PROB_FAIR, COUNT_UNKNOWN);
4505   head->init_req(2, IfTrue(iff));
4506   mem->init_req(2, st);
4507   i_byte->init_req(2, AddI(i_byte, intcon(1)));
4508   i_char->init_req(2, AddI(i_char, intcon(2)));
4509 
4510   set_control(IfFalse(iff));
4511   set_memory(st, TypeAryPtr::BYTES);
4512 }
4513 
4514 Node* GraphKit::make_constant_from_field(ciField* field, Node* obj) {
4515   if (!field->is_constant()) {
4516     return NULL; // Field not marked as constant.
4517   }
4518   ciInstance* holder = NULL;
4519   if (!field->is_static()) {
4520     ciObject* const_oop = obj->bottom_type()->is_oopptr()->const_oop();
4521     if (const_oop != NULL && const_oop->is_instance()) {
4522       holder = const_oop->as_instance();
4523     }
4524   }
4525   const Type* con_type = Type::make_constant_from_field(field, holder, field->layout_type(),
4526                                                         /*is_unsigned_load=*/false);
4527   if (con_type != NULL) {
4528     return makecon(con_type);
4529   }
4530   return NULL;
4531 }
4532 
4533 Node* GraphKit::cast_array_to_stable(Node* ary, const TypeAryPtr* ary_type) {
4534   // Reify the property as a CastPP node in Ideal graph to comply with monotonicity
4535   // assumption of CCP analysis.
4536   return _gvn.transform(new CastPPNode(ary, ary_type->cast_to_stable(true)));
4537 }
4538 
4539 Node* GraphKit::acmp(Node* a, Node* b) {
4540   // In the case were both operands might be value types, we need to
4541   // use the new acmp implementation. Otherwise, i.e. if one operand
4542   // is not a value type, we can use the old acmp implementation.
4543   Node* cmp = C->optimize_acmp(&_gvn, a, b);
4544   if (cmp != NULL) {
4545     return cmp; // Use optimized/old acmp
4546   }
4547 
4548   Node* region = new RegionNode(2);
4549   Node* is_value = new PhiNode(region, TypeX_X);
4550 
4551   // Null check operand before loading the is_value bit
4552   if (!TypePtr::NULL_PTR->higher_equal(_gvn.type(b))) {
4553     // Operand 'b' is never null, swap operands to avoid null check
4554     swap(a, b);
4555   }
4556   // TODO we need to speculate on 'a' being non-null / always null
4557   Node* null_ctl = top();
4558   Node* not_null_a = null_check_oop(a, &null_ctl);
4559   assert(!stopped(), "operand is always null");
4560   if (null_ctl != top()) {
4561     region->add_req(null_ctl);
4562     is_value->add_req(_gvn.MakeConX(0));
4563     if (Verbose) tty->print_cr("\n# NEW (parse time)");
4564   } else {
4565     if (Verbose) tty->print_cr("\n# NEW WITHOUT NULL (parse time)");
4566   }
4567 
4568   Node* value_bit = C->load_is_value_bit(&_gvn, not_null_a);
4569   region->init_req(1, control());
4570   is_value->set_req(1, value_bit);
4571 
4572   set_control(_gvn.transform(region));
4573   is_value = _gvn.transform(is_value);
4574 
4575   // Perturbe oop if operand is a value type to make comparison fail
4576   Node* pert = _gvn.transform(new AddPNode(a, a, is_value));
4577   return new CmpPNode(pert, b);
4578 }
--- EOF ---