1 /*
   2  * Copyright (c) 2001, 2016, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "compiler/compileLog.hpp"
  27 #include "ci/ciValueKlass.hpp"
  28 #include "gc/g1/g1SATBCardTableModRefBS.hpp"
  29 #include "gc/g1/heapRegion.hpp"
  30 #include "gc/shared/barrierSet.hpp"
  31 #include "gc/shared/cardTableModRefBS.hpp"
  32 #include "gc/shared/collectedHeap.hpp"
  33 #include "memory/resourceArea.hpp"
  34 #include "opto/addnode.hpp"
  35 #include "opto/castnode.hpp"
  36 #include "opto/convertnode.hpp"
  37 #include "opto/graphKit.hpp"
  38 #include "opto/idealKit.hpp"
  39 #include "opto/intrinsicnode.hpp"
  40 #include "opto/locknode.hpp"
  41 #include "opto/machnode.hpp"
  42 #include "opto/opaquenode.hpp"
  43 #include "opto/parse.hpp"
  44 #include "opto/rootnode.hpp"
  45 #include "opto/runtime.hpp"
  46 #include "opto/valuetypenode.hpp"
  47 #include "runtime/deoptimization.hpp"
  48 #include "runtime/sharedRuntime.hpp"
  49 
  50 //----------------------------GraphKit-----------------------------------------
  51 // Main utility constructor.
  52 GraphKit::GraphKit(JVMState* jvms)
  53   : Phase(Phase::Parser),
  54     _env(C->env()),
  55     _gvn(*C->initial_gvn())
  56 {
  57   _exceptions = jvms->map()->next_exception();
  58   if (_exceptions != NULL)  jvms->map()->set_next_exception(NULL);
  59   set_jvms(jvms);
  60 }
  61 
  62 // Private constructor for parser.
  63 GraphKit::GraphKit()
  64   : Phase(Phase::Parser),
  65     _env(C->env()),
  66     _gvn(*C->initial_gvn())
  67 {
  68   _exceptions = NULL;
  69   set_map(NULL);
  70   debug_only(_sp = -99);
  71   debug_only(set_bci(-99));
  72 }
  73 
  74 
  75 
  76 //---------------------------clean_stack---------------------------------------
  77 // Clear away rubbish from the stack area of the JVM state.
  78 // This destroys any arguments that may be waiting on the stack.
  79 void GraphKit::clean_stack(int from_sp) {
  80   SafePointNode* map      = this->map();
  81   JVMState*      jvms     = this->jvms();
  82   int            stk_size = jvms->stk_size();
  83   int            stkoff   = jvms->stkoff();
  84   Node*          top      = this->top();
  85   for (int i = from_sp; i < stk_size; i++) {
  86     if (map->in(stkoff + i) != top) {
  87       map->set_req(stkoff + i, top);
  88     }
  89   }
  90 }
  91 
  92 
  93 //--------------------------------sync_jvms-----------------------------------
  94 // Make sure our current jvms agrees with our parse state.
  95 JVMState* GraphKit::sync_jvms() const {
  96   JVMState* jvms = this->jvms();
  97   jvms->set_bci(bci());       // Record the new bci in the JVMState
  98   jvms->set_sp(sp());         // Record the new sp in the JVMState
  99   assert(jvms_in_sync(), "jvms is now in sync");
 100   return jvms;
 101 }
 102 
 103 //--------------------------------sync_jvms_for_reexecute---------------------
 104 // Make sure our current jvms agrees with our parse state.  This version
 105 // uses the reexecute_sp for reexecuting bytecodes.
 106 JVMState* GraphKit::sync_jvms_for_reexecute() {
 107   JVMState* jvms = this->jvms();
 108   jvms->set_bci(bci());          // Record the new bci in the JVMState
 109   jvms->set_sp(reexecute_sp());  // Record the new sp in the JVMState
 110   return jvms;
 111 }
 112 
 113 #ifdef ASSERT
 114 bool GraphKit::jvms_in_sync() const {
 115   Parse* parse = is_Parse();
 116   if (parse == NULL) {
 117     if (bci() !=      jvms()->bci())          return false;
 118     if (sp()  != (int)jvms()->sp())           return false;
 119     return true;
 120   }
 121   if (jvms()->method() != parse->method())    return false;
 122   if (jvms()->bci()    != parse->bci())       return false;
 123   int jvms_sp = jvms()->sp();
 124   if (jvms_sp          != parse->sp())        return false;
 125   int jvms_depth = jvms()->depth();
 126   if (jvms_depth       != parse->depth())     return false;
 127   return true;
 128 }
 129 
 130 // Local helper checks for special internal merge points
 131 // used to accumulate and merge exception states.
 132 // They are marked by the region's in(0) edge being the map itself.
 133 // Such merge points must never "escape" into the parser at large,
 134 // until they have been handed to gvn.transform.
 135 static bool is_hidden_merge(Node* reg) {
 136   if (reg == NULL)  return false;
 137   if (reg->is_Phi()) {
 138     reg = reg->in(0);
 139     if (reg == NULL)  return false;
 140   }
 141   return reg->is_Region() && reg->in(0) != NULL && reg->in(0)->is_Root();
 142 }
 143 
 144 void GraphKit::verify_map() const {
 145   if (map() == NULL)  return;  // null map is OK
 146   assert(map()->req() <= jvms()->endoff(), "no extra garbage on map");
 147   assert(!map()->has_exceptions(),    "call add_exception_states_from 1st");
 148   assert(!is_hidden_merge(control()), "call use_exception_state, not set_map");
 149 }
 150 
 151 void GraphKit::verify_exception_state(SafePointNode* ex_map) {
 152   assert(ex_map->next_exception() == NULL, "not already part of a chain");
 153   assert(has_saved_ex_oop(ex_map), "every exception state has an ex_oop");
 154 }
 155 #endif
 156 
 157 //---------------------------stop_and_kill_map---------------------------------
 158 // Set _map to NULL, signalling a stop to further bytecode execution.
 159 // First smash the current map's control to a constant, to mark it dead.
 160 void GraphKit::stop_and_kill_map() {
 161   SafePointNode* dead_map = stop();
 162   if (dead_map != NULL) {
 163     dead_map->disconnect_inputs(NULL, C); // Mark the map as killed.
 164     assert(dead_map->is_killed(), "must be so marked");
 165   }
 166 }
 167 
 168 
 169 //--------------------------------stopped--------------------------------------
 170 // Tell if _map is NULL, or control is top.
 171 bool GraphKit::stopped() {
 172   if (map() == NULL)           return true;
 173   else if (control() == top()) return true;
 174   else                         return false;
 175 }
 176 
 177 
 178 //-----------------------------has_ex_handler----------------------------------
 179 // Tell if this method or any caller method has exception handlers.
 180 bool GraphKit::has_ex_handler() {
 181   for (JVMState* jvmsp = jvms(); jvmsp != NULL; jvmsp = jvmsp->caller()) {
 182     if (jvmsp->has_method() && jvmsp->method()->has_exception_handlers()) {
 183       return true;
 184     }
 185   }
 186   return false;
 187 }
 188 
 189 //------------------------------save_ex_oop------------------------------------
 190 // Save an exception without blowing stack contents or other JVM state.
 191 void GraphKit::set_saved_ex_oop(SafePointNode* ex_map, Node* ex_oop) {
 192   assert(!has_saved_ex_oop(ex_map), "clear ex-oop before setting again");
 193   ex_map->add_req(ex_oop);
 194   debug_only(verify_exception_state(ex_map));
 195 }
 196 
 197 inline static Node* common_saved_ex_oop(SafePointNode* ex_map, bool clear_it) {
 198   assert(GraphKit::has_saved_ex_oop(ex_map), "ex_oop must be there");
 199   Node* ex_oop = ex_map->in(ex_map->req()-1);
 200   if (clear_it)  ex_map->del_req(ex_map->req()-1);
 201   return ex_oop;
 202 }
 203 
 204 //-----------------------------saved_ex_oop------------------------------------
 205 // Recover a saved exception from its map.
 206 Node* GraphKit::saved_ex_oop(SafePointNode* ex_map) {
 207   return common_saved_ex_oop(ex_map, false);
 208 }
 209 
 210 //--------------------------clear_saved_ex_oop---------------------------------
 211 // Erase a previously saved exception from its map.
 212 Node* GraphKit::clear_saved_ex_oop(SafePointNode* ex_map) {
 213   return common_saved_ex_oop(ex_map, true);
 214 }
 215 
 216 #ifdef ASSERT
 217 //---------------------------has_saved_ex_oop----------------------------------
 218 // Erase a previously saved exception from its map.
 219 bool GraphKit::has_saved_ex_oop(SafePointNode* ex_map) {
 220   return ex_map->req() == ex_map->jvms()->endoff()+1;
 221 }
 222 #endif
 223 
 224 //-------------------------make_exception_state--------------------------------
 225 // Turn the current JVM state into an exception state, appending the ex_oop.
 226 SafePointNode* GraphKit::make_exception_state(Node* ex_oop) {
 227   sync_jvms();
 228   SafePointNode* ex_map = stop();  // do not manipulate this map any more
 229   set_saved_ex_oop(ex_map, ex_oop);
 230   return ex_map;
 231 }
 232 
 233 
 234 //--------------------------add_exception_state--------------------------------
 235 // Add an exception to my list of exceptions.
 236 void GraphKit::add_exception_state(SafePointNode* ex_map) {
 237   if (ex_map == NULL || ex_map->control() == top()) {
 238     return;
 239   }
 240 #ifdef ASSERT
 241   verify_exception_state(ex_map);
 242   if (has_exceptions()) {
 243     assert(ex_map->jvms()->same_calls_as(_exceptions->jvms()), "all collected exceptions must come from the same place");
 244   }
 245 #endif
 246 
 247   // If there is already an exception of exactly this type, merge with it.
 248   // In particular, null-checks and other low-level exceptions common up here.
 249   Node*       ex_oop  = saved_ex_oop(ex_map);
 250   const Type* ex_type = _gvn.type(ex_oop);
 251   if (ex_oop == top()) {
 252     // No action needed.
 253     return;
 254   }
 255   assert(ex_type->isa_instptr(), "exception must be an instance");
 256   for (SafePointNode* e2 = _exceptions; e2 != NULL; e2 = e2->next_exception()) {
 257     const Type* ex_type2 = _gvn.type(saved_ex_oop(e2));
 258     // We check sp also because call bytecodes can generate exceptions
 259     // both before and after arguments are popped!
 260     if (ex_type2 == ex_type
 261         && e2->_jvms->sp() == ex_map->_jvms->sp()) {
 262       combine_exception_states(ex_map, e2);
 263       return;
 264     }
 265   }
 266 
 267   // No pre-existing exception of the same type.  Chain it on the list.
 268   push_exception_state(ex_map);
 269 }
 270 
 271 //-----------------------add_exception_states_from-----------------------------
 272 void GraphKit::add_exception_states_from(JVMState* jvms) {
 273   SafePointNode* ex_map = jvms->map()->next_exception();
 274   if (ex_map != NULL) {
 275     jvms->map()->set_next_exception(NULL);
 276     for (SafePointNode* next_map; ex_map != NULL; ex_map = next_map) {
 277       next_map = ex_map->next_exception();
 278       ex_map->set_next_exception(NULL);
 279       add_exception_state(ex_map);
 280     }
 281   }
 282 }
 283 
 284 //-----------------------transfer_exceptions_into_jvms-------------------------
 285 JVMState* GraphKit::transfer_exceptions_into_jvms() {
 286   if (map() == NULL) {
 287     // We need a JVMS to carry the exceptions, but the map has gone away.
 288     // Create a scratch JVMS, cloned from any of the exception states...
 289     if (has_exceptions()) {
 290       _map = _exceptions;
 291       _map = clone_map();
 292       _map->set_next_exception(NULL);
 293       clear_saved_ex_oop(_map);
 294       debug_only(verify_map());
 295     } else {
 296       // ...or created from scratch
 297       JVMState* jvms = new (C) JVMState(_method, NULL);
 298       jvms->set_bci(_bci);
 299       jvms->set_sp(_sp);
 300       jvms->set_map(new SafePointNode(TypeFunc::Parms, jvms));
 301       set_jvms(jvms);
 302       for (uint i = 0; i < map()->req(); i++)  map()->init_req(i, top());
 303       set_all_memory(top());
 304       while (map()->req() < jvms->endoff())  map()->add_req(top());
 305     }
 306     // (This is a kludge, in case you didn't notice.)
 307     set_control(top());
 308   }
 309   JVMState* jvms = sync_jvms();
 310   assert(!jvms->map()->has_exceptions(), "no exceptions on this map yet");
 311   jvms->map()->set_next_exception(_exceptions);
 312   _exceptions = NULL;   // done with this set of exceptions
 313   return jvms;
 314 }
 315 
 316 static inline void add_n_reqs(Node* dstphi, Node* srcphi) {
 317   assert(is_hidden_merge(dstphi), "must be a special merge node");
 318   assert(is_hidden_merge(srcphi), "must be a special merge node");
 319   uint limit = srcphi->req();
 320   for (uint i = PhiNode::Input; i < limit; i++) {
 321     dstphi->add_req(srcphi->in(i));
 322   }
 323 }
 324 static inline void add_one_req(Node* dstphi, Node* src) {
 325   assert(is_hidden_merge(dstphi), "must be a special merge node");
 326   assert(!is_hidden_merge(src), "must not be a special merge node");
 327   dstphi->add_req(src);
 328 }
 329 
 330 //-----------------------combine_exception_states------------------------------
 331 // This helper function combines exception states by building phis on a
 332 // specially marked state-merging region.  These regions and phis are
 333 // untransformed, and can build up gradually.  The region is marked by
 334 // having a control input of its exception map, rather than NULL.  Such
 335 // regions do not appear except in this function, and in use_exception_state.
 336 void GraphKit::combine_exception_states(SafePointNode* ex_map, SafePointNode* phi_map) {
 337   if (failing())  return;  // dying anyway...
 338   JVMState* ex_jvms = ex_map->_jvms;
 339   assert(ex_jvms->same_calls_as(phi_map->_jvms), "consistent call chains");
 340   assert(ex_jvms->stkoff() == phi_map->_jvms->stkoff(), "matching locals");
 341   assert(ex_jvms->sp() == phi_map->_jvms->sp(), "matching stack sizes");
 342   assert(ex_jvms->monoff() == phi_map->_jvms->monoff(), "matching JVMS");
 343   assert(ex_jvms->scloff() == phi_map->_jvms->scloff(), "matching scalar replaced objects");
 344   assert(ex_map->req() == phi_map->req(), "matching maps");
 345   uint tos = ex_jvms->stkoff() + ex_jvms->sp();
 346   Node*         hidden_merge_mark = root();
 347   Node*         region  = phi_map->control();
 348   MergeMemNode* phi_mem = phi_map->merged_memory();
 349   MergeMemNode* ex_mem  = ex_map->merged_memory();
 350   if (region->in(0) != hidden_merge_mark) {
 351     // The control input is not (yet) a specially-marked region in phi_map.
 352     // Make it so, and build some phis.
 353     region = new RegionNode(2);
 354     _gvn.set_type(region, Type::CONTROL);
 355     region->set_req(0, hidden_merge_mark);  // marks an internal ex-state
 356     region->init_req(1, phi_map->control());
 357     phi_map->set_control(region);
 358     Node* io_phi = PhiNode::make(region, phi_map->i_o(), Type::ABIO);
 359     record_for_igvn(io_phi);
 360     _gvn.set_type(io_phi, Type::ABIO);
 361     phi_map->set_i_o(io_phi);
 362     for (MergeMemStream mms(phi_mem); mms.next_non_empty(); ) {
 363       Node* m = mms.memory();
 364       Node* m_phi = PhiNode::make(region, m, Type::MEMORY, mms.adr_type(C));
 365       record_for_igvn(m_phi);
 366       _gvn.set_type(m_phi, Type::MEMORY);
 367       mms.set_memory(m_phi);
 368     }
 369   }
 370 
 371   // Either or both of phi_map and ex_map might already be converted into phis.
 372   Node* ex_control = ex_map->control();
 373   // if there is special marking on ex_map also, we add multiple edges from src
 374   bool add_multiple = (ex_control->in(0) == hidden_merge_mark);
 375   // how wide was the destination phi_map, originally?
 376   uint orig_width = region->req();
 377 
 378   if (add_multiple) {
 379     add_n_reqs(region, ex_control);
 380     add_n_reqs(phi_map->i_o(), ex_map->i_o());
 381   } else {
 382     // ex_map has no merges, so we just add single edges everywhere
 383     add_one_req(region, ex_control);
 384     add_one_req(phi_map->i_o(), ex_map->i_o());
 385   }
 386   for (MergeMemStream mms(phi_mem, ex_mem); mms.next_non_empty2(); ) {
 387     if (mms.is_empty()) {
 388       // get a copy of the base memory, and patch some inputs into it
 389       const TypePtr* adr_type = mms.adr_type(C);
 390       Node* phi = mms.force_memory()->as_Phi()->slice_memory(adr_type);
 391       assert(phi->as_Phi()->region() == mms.base_memory()->in(0), "");
 392       mms.set_memory(phi);
 393       // Prepare to append interesting stuff onto the newly sliced phi:
 394       while (phi->req() > orig_width)  phi->del_req(phi->req()-1);
 395     }
 396     // Append stuff from ex_map:
 397     if (add_multiple) {
 398       add_n_reqs(mms.memory(), mms.memory2());
 399     } else {
 400       add_one_req(mms.memory(), mms.memory2());
 401     }
 402   }
 403   uint limit = ex_map->req();
 404   for (uint i = TypeFunc::Parms; i < limit; i++) {
 405     // Skip everything in the JVMS after tos.  (The ex_oop follows.)
 406     if (i == tos)  i = ex_jvms->monoff();
 407     Node* src = ex_map->in(i);
 408     Node* dst = phi_map->in(i);
 409     if (src != dst) {
 410       PhiNode* phi;
 411       if (dst->in(0) != region) {
 412         dst = phi = PhiNode::make(region, dst, _gvn.type(dst));
 413         record_for_igvn(phi);
 414         _gvn.set_type(phi, phi->type());
 415         phi_map->set_req(i, dst);
 416         // Prepare to append interesting stuff onto the new phi:
 417         while (dst->req() > orig_width)  dst->del_req(dst->req()-1);
 418       } else {
 419         assert(dst->is_Phi(), "nobody else uses a hidden region");
 420         phi = dst->as_Phi();
 421       }
 422       if (add_multiple && src->in(0) == ex_control) {
 423         // Both are phis.
 424         add_n_reqs(dst, src);
 425       } else {
 426         while (dst->req() < region->req())  add_one_req(dst, src);
 427       }
 428       const Type* srctype = _gvn.type(src);
 429       if (phi->type() != srctype) {
 430         const Type* dsttype = phi->type()->meet_speculative(srctype);
 431         if (phi->type() != dsttype) {
 432           phi->set_type(dsttype);
 433           _gvn.set_type(phi, dsttype);
 434         }
 435       }
 436     }
 437   }
 438   phi_map->merge_replaced_nodes_with(ex_map);
 439 }
 440 
 441 //--------------------------use_exception_state--------------------------------
 442 Node* GraphKit::use_exception_state(SafePointNode* phi_map) {
 443   if (failing()) { stop(); return top(); }
 444   Node* region = phi_map->control();
 445   Node* hidden_merge_mark = root();
 446   assert(phi_map->jvms()->map() == phi_map, "sanity: 1-1 relation");
 447   Node* ex_oop = clear_saved_ex_oop(phi_map);
 448   if (region->in(0) == hidden_merge_mark) {
 449     // Special marking for internal ex-states.  Process the phis now.
 450     region->set_req(0, region);  // now it's an ordinary region
 451     set_jvms(phi_map->jvms());   // ...so now we can use it as a map
 452     // Note: Setting the jvms also sets the bci and sp.
 453     set_control(_gvn.transform(region));
 454     uint tos = jvms()->stkoff() + sp();
 455     for (uint i = 1; i < tos; i++) {
 456       Node* x = phi_map->in(i);
 457       if (x->in(0) == region) {
 458         assert(x->is_Phi(), "expected a special phi");
 459         phi_map->set_req(i, _gvn.transform(x));
 460       }
 461     }
 462     for (MergeMemStream mms(merged_memory()); mms.next_non_empty(); ) {
 463       Node* x = mms.memory();
 464       if (x->in(0) == region) {
 465         assert(x->is_Phi(), "nobody else uses a hidden region");
 466         mms.set_memory(_gvn.transform(x));
 467       }
 468     }
 469     if (ex_oop->in(0) == region) {
 470       assert(ex_oop->is_Phi(), "expected a special phi");
 471       ex_oop = _gvn.transform(ex_oop);
 472     }
 473   } else {
 474     set_jvms(phi_map->jvms());
 475   }
 476 
 477   assert(!is_hidden_merge(phi_map->control()), "hidden ex. states cleared");
 478   assert(!is_hidden_merge(phi_map->i_o()), "hidden ex. states cleared");
 479   return ex_oop;
 480 }
 481 
 482 //---------------------------------java_bc-------------------------------------
 483 Bytecodes::Code GraphKit::java_bc() const {
 484   ciMethod* method = this->method();
 485   int       bci    = this->bci();
 486   if (method != NULL && bci != InvocationEntryBci)
 487     return method->java_code_at_bci(bci);
 488   else
 489     return Bytecodes::_illegal;
 490 }
 491 
 492 void GraphKit::uncommon_trap_if_should_post_on_exceptions(Deoptimization::DeoptReason reason,
 493                                                           bool must_throw) {
 494     // if the exception capability is set, then we will generate code
 495     // to check the JavaThread.should_post_on_exceptions flag to see
 496     // if we actually need to report exception events (for this
 497     // thread).  If we don't need to report exception events, we will
 498     // take the normal fast path provided by add_exception_events.  If
 499     // exception event reporting is enabled for this thread, we will
 500     // take the uncommon_trap in the BuildCutout below.
 501 
 502     // first must access the should_post_on_exceptions_flag in this thread's JavaThread
 503     Node* jthread = _gvn.transform(new ThreadLocalNode());
 504     Node* adr = basic_plus_adr(top(), jthread, in_bytes(JavaThread::should_post_on_exceptions_flag_offset()));
 505     Node* should_post_flag = make_load(control(), adr, TypeInt::INT, T_INT, Compile::AliasIdxRaw, MemNode::unordered);
 506 
 507     // Test the should_post_on_exceptions_flag vs. 0
 508     Node* chk = _gvn.transform( new CmpINode(should_post_flag, intcon(0)) );
 509     Node* tst = _gvn.transform( new BoolNode(chk, BoolTest::eq) );
 510 
 511     // Branch to slow_path if should_post_on_exceptions_flag was true
 512     { BuildCutout unless(this, tst, PROB_MAX);
 513       // Do not try anything fancy if we're notifying the VM on every throw.
 514       // Cf. case Bytecodes::_athrow in parse2.cpp.
 515       uncommon_trap(reason, Deoptimization::Action_none,
 516                     (ciKlass*)NULL, (char*)NULL, must_throw);
 517     }
 518 
 519 }
 520 
 521 //------------------------------builtin_throw----------------------------------
 522 void GraphKit::builtin_throw(Deoptimization::DeoptReason reason, Node* arg) {
 523   bool must_throw = true;
 524 
 525   if (env()->jvmti_can_post_on_exceptions()) {
 526     // check if we must post exception events, take uncommon trap if so
 527     uncommon_trap_if_should_post_on_exceptions(reason, must_throw);
 528     // here if should_post_on_exceptions is false
 529     // continue on with the normal codegen
 530   }
 531 
 532   // If this particular condition has not yet happened at this
 533   // bytecode, then use the uncommon trap mechanism, and allow for
 534   // a future recompilation if several traps occur here.
 535   // If the throw is hot, try to use a more complicated inline mechanism
 536   // which keeps execution inside the compiled code.
 537   bool treat_throw_as_hot = false;
 538   ciMethodData* md = method()->method_data();
 539 
 540   if (ProfileTraps) {
 541     if (too_many_traps(reason)) {
 542       treat_throw_as_hot = true;
 543     }
 544     // (If there is no MDO at all, assume it is early in
 545     // execution, and that any deopts are part of the
 546     // startup transient, and don't need to be remembered.)
 547 
 548     // Also, if there is a local exception handler, treat all throws
 549     // as hot if there has been at least one in this method.
 550     if (C->trap_count(reason) != 0
 551         && method()->method_data()->trap_count(reason) != 0
 552         && has_ex_handler()) {
 553         treat_throw_as_hot = true;
 554     }
 555   }
 556 
 557   // If this throw happens frequently, an uncommon trap might cause
 558   // a performance pothole.  If there is a local exception handler,
 559   // and if this particular bytecode appears to be deoptimizing often,
 560   // let us handle the throw inline, with a preconstructed instance.
 561   // Note:   If the deopt count has blown up, the uncommon trap
 562   // runtime is going to flush this nmethod, not matter what.
 563   if (treat_throw_as_hot
 564       && (!StackTraceInThrowable || OmitStackTraceInFastThrow)) {
 565     // If the throw is local, we use a pre-existing instance and
 566     // punt on the backtrace.  This would lead to a missing backtrace
 567     // (a repeat of 4292742) if the backtrace object is ever asked
 568     // for its backtrace.
 569     // Fixing this remaining case of 4292742 requires some flavor of
 570     // escape analysis.  Leave that for the future.
 571     ciInstance* ex_obj = NULL;
 572     switch (reason) {
 573     case Deoptimization::Reason_null_check:
 574       ex_obj = env()->NullPointerException_instance();
 575       break;
 576     case Deoptimization::Reason_div0_check:
 577       ex_obj = env()->ArithmeticException_instance();
 578       break;
 579     case Deoptimization::Reason_range_check:
 580       ex_obj = env()->ArrayIndexOutOfBoundsException_instance();
 581       break;
 582     case Deoptimization::Reason_class_check:
 583       if (java_bc() == Bytecodes::_aastore) {
 584         ex_obj = env()->ArrayStoreException_instance();
 585       } else {
 586         ex_obj = env()->ClassCastException_instance();
 587       }
 588       break;
 589     }
 590     if (failing()) { stop(); return; }  // exception allocation might fail
 591     if (ex_obj != NULL) {
 592       // Cheat with a preallocated exception object.
 593       if (C->log() != NULL)
 594         C->log()->elem("hot_throw preallocated='1' reason='%s'",
 595                        Deoptimization::trap_reason_name(reason));
 596       const TypeInstPtr* ex_con  = TypeInstPtr::make(ex_obj);
 597       Node*              ex_node = _gvn.transform(ConNode::make(ex_con));
 598 
 599       // Clear the detail message of the preallocated exception object.
 600       // Weblogic sometimes mutates the detail message of exceptions
 601       // using reflection.
 602       int offset = java_lang_Throwable::get_detailMessage_offset();
 603       const TypePtr* adr_typ = ex_con->add_offset(offset);
 604 
 605       Node *adr = basic_plus_adr(ex_node, ex_node, offset);
 606       const TypeOopPtr* val_type = TypeOopPtr::make_from_klass(env()->String_klass());
 607       // Conservatively release stores of object references.
 608       Node *store = store_oop_to_object(control(), ex_node, adr, adr_typ, null(), val_type, T_OBJECT, MemNode::release);
 609 
 610       add_exception_state(make_exception_state(ex_node));
 611       return;
 612     }
 613   }
 614 
 615   // %%% Maybe add entry to OptoRuntime which directly throws the exc.?
 616   // It won't be much cheaper than bailing to the interp., since we'll
 617   // have to pass up all the debug-info, and the runtime will have to
 618   // create the stack trace.
 619 
 620   // Usual case:  Bail to interpreter.
 621   // Reserve the right to recompile if we haven't seen anything yet.
 622 
 623   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? C->method() : NULL;
 624   Deoptimization::DeoptAction action = Deoptimization::Action_maybe_recompile;
 625   if (treat_throw_as_hot
 626       && (method()->method_data()->trap_recompiled_at(bci(), m)
 627           || C->too_many_traps(reason))) {
 628     // We cannot afford to take more traps here.  Suffer in the interpreter.
 629     if (C->log() != NULL)
 630       C->log()->elem("hot_throw preallocated='0' reason='%s' mcount='%d'",
 631                      Deoptimization::trap_reason_name(reason),
 632                      C->trap_count(reason));
 633     action = Deoptimization::Action_none;
 634   }
 635 
 636   // "must_throw" prunes the JVM state to include only the stack, if there
 637   // are no local exception handlers.  This should cut down on register
 638   // allocation time and code size, by drastically reducing the number
 639   // of in-edges on the call to the uncommon trap.
 640 
 641   uncommon_trap(reason, action, (ciKlass*)NULL, (char*)NULL, must_throw);
 642 }
 643 
 644 
 645 //----------------------------PreserveJVMState---------------------------------
 646 PreserveJVMState::PreserveJVMState(GraphKit* kit, bool clone_map) {
 647   debug_only(kit->verify_map());
 648   _kit    = kit;
 649   _map    = kit->map();   // preserve the map
 650   _sp     = kit->sp();
 651   kit->set_map(clone_map ? kit->clone_map() : NULL);
 652 #ifdef ASSERT
 653   _bci    = kit->bci();
 654   Parse* parser = kit->is_Parse();
 655   int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo();
 656   _block  = block;
 657 #endif
 658 }
 659 PreserveJVMState::~PreserveJVMState() {
 660   GraphKit* kit = _kit;
 661 #ifdef ASSERT
 662   assert(kit->bci() == _bci, "bci must not shift");
 663   Parse* parser = kit->is_Parse();
 664   int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo();
 665   assert(block == _block,    "block must not shift");
 666 #endif
 667   kit->set_map(_map);
 668   kit->set_sp(_sp);
 669 }
 670 
 671 
 672 //-----------------------------BuildCutout-------------------------------------
 673 BuildCutout::BuildCutout(GraphKit* kit, Node* p, float prob, float cnt)
 674   : PreserveJVMState(kit)
 675 {
 676   assert(p->is_Con() || p->is_Bool(), "test must be a bool");
 677   SafePointNode* outer_map = _map;   // preserved map is caller's
 678   SafePointNode* inner_map = kit->map();
 679   IfNode* iff = kit->create_and_map_if(outer_map->control(), p, prob, cnt);
 680   outer_map->set_control(kit->gvn().transform( new IfTrueNode(iff) ));
 681   inner_map->set_control(kit->gvn().transform( new IfFalseNode(iff) ));
 682 }
 683 BuildCutout::~BuildCutout() {
 684   GraphKit* kit = _kit;
 685   assert(kit->stopped(), "cutout code must stop, throw, return, etc.");
 686 }
 687 
 688 //---------------------------PreserveReexecuteState----------------------------
 689 PreserveReexecuteState::PreserveReexecuteState(GraphKit* kit) {
 690   assert(!kit->stopped(), "must call stopped() before");
 691   _kit    =    kit;
 692   _sp     =    kit->sp();
 693   _reexecute = kit->jvms()->_reexecute;
 694 }
 695 PreserveReexecuteState::~PreserveReexecuteState() {
 696   if (_kit->stopped()) return;
 697   _kit->jvms()->_reexecute = _reexecute;
 698   _kit->set_sp(_sp);
 699 }
 700 
 701 //------------------------------clone_map--------------------------------------
 702 // Implementation of PreserveJVMState
 703 //
 704 // Only clone_map(...) here. If this function is only used in the
 705 // PreserveJVMState class we may want to get rid of this extra
 706 // function eventually and do it all there.
 707 
 708 SafePointNode* GraphKit::clone_map() {
 709   if (map() == NULL)  return NULL;
 710 
 711   // Clone the memory edge first
 712   Node* mem = MergeMemNode::make(map()->memory());
 713   gvn().set_type_bottom(mem);
 714 
 715   SafePointNode *clonemap = (SafePointNode*)map()->clone();
 716   JVMState* jvms = this->jvms();
 717   JVMState* clonejvms = jvms->clone_shallow(C);
 718   clonemap->set_memory(mem);
 719   clonemap->set_jvms(clonejvms);
 720   clonejvms->set_map(clonemap);
 721   record_for_igvn(clonemap);
 722   gvn().set_type_bottom(clonemap);
 723   return clonemap;
 724 }
 725 
 726 
 727 //-----------------------------set_map_clone-----------------------------------
 728 void GraphKit::set_map_clone(SafePointNode* m) {
 729   _map = m;
 730   _map = clone_map();
 731   _map->set_next_exception(NULL);
 732   debug_only(verify_map());
 733 }
 734 
 735 
 736 //----------------------------kill_dead_locals---------------------------------
 737 // Detect any locals which are known to be dead, and force them to top.
 738 void GraphKit::kill_dead_locals() {
 739   // Consult the liveness information for the locals.  If any
 740   // of them are unused, then they can be replaced by top().  This
 741   // should help register allocation time and cut down on the size
 742   // of the deoptimization information.
 743 
 744   // This call is made from many of the bytecode handling
 745   // subroutines called from the Big Switch in do_one_bytecode.
 746   // Every bytecode which might include a slow path is responsible
 747   // for killing its dead locals.  The more consistent we
 748   // are about killing deads, the fewer useless phis will be
 749   // constructed for them at various merge points.
 750 
 751   // bci can be -1 (InvocationEntryBci).  We return the entry
 752   // liveness for the method.
 753 
 754   if (method() == NULL || method()->code_size() == 0) {
 755     // We are building a graph for a call to a native method.
 756     // All locals are live.
 757     return;
 758   }
 759 
 760   ResourceMark rm;
 761 
 762   // Consult the liveness information for the locals.  If any
 763   // of them are unused, then they can be replaced by top().  This
 764   // should help register allocation time and cut down on the size
 765   // of the deoptimization information.
 766   MethodLivenessResult live_locals = method()->liveness_at_bci(bci());
 767 
 768   int len = (int)live_locals.size();
 769   assert(len <= jvms()->loc_size(), "too many live locals");
 770   for (int local = 0; local < len; local++) {
 771     if (!live_locals.at(local)) {
 772       set_local(local, top());
 773     }
 774   }
 775 }
 776 
 777 #ifdef ASSERT
 778 //-------------------------dead_locals_are_killed------------------------------
 779 // Return true if all dead locals are set to top in the map.
 780 // Used to assert "clean" debug info at various points.
 781 bool GraphKit::dead_locals_are_killed() {
 782   if (method() == NULL || method()->code_size() == 0) {
 783     // No locals need to be dead, so all is as it should be.
 784     return true;
 785   }
 786 
 787   // Make sure somebody called kill_dead_locals upstream.
 788   ResourceMark rm;
 789   for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) {
 790     if (jvms->loc_size() == 0)  continue;  // no locals to consult
 791     SafePointNode* map = jvms->map();
 792     ciMethod* method = jvms->method();
 793     int       bci    = jvms->bci();
 794     if (jvms == this->jvms()) {
 795       bci = this->bci();  // it might not yet be synched
 796     }
 797     MethodLivenessResult live_locals = method->liveness_at_bci(bci);
 798     int len = (int)live_locals.size();
 799     if (!live_locals.is_valid() || len == 0)
 800       // This method is trivial, or is poisoned by a breakpoint.
 801       return true;
 802     assert(len == jvms->loc_size(), "live map consistent with locals map");
 803     for (int local = 0; local < len; local++) {
 804       if (!live_locals.at(local) && map->local(jvms, local) != top()) {
 805         if (PrintMiscellaneous && (Verbose || WizardMode)) {
 806           tty->print_cr("Zombie local %d: ", local);
 807           jvms->dump();
 808         }
 809         return false;
 810       }
 811     }
 812   }
 813   return true;
 814 }
 815 
 816 #endif //ASSERT
 817 
 818 // Helper function for adding JVMState and debug information to node
 819 void GraphKit::add_safepoint_edges(SafePointNode* call, bool must_throw) {
 820   // Add the safepoint edges to the call (or other safepoint).
 821 
 822   // Make sure dead locals are set to top.  This
 823   // should help register allocation time and cut down on the size
 824   // of the deoptimization information.
 825   assert(dead_locals_are_killed(), "garbage in debug info before safepoint");
 826 
 827   // Walk the inline list to fill in the correct set of JVMState's
 828   // Also fill in the associated edges for each JVMState.
 829 
 830   // If the bytecode needs to be reexecuted we need to put
 831   // the arguments back on the stack.
 832   const bool should_reexecute = jvms()->should_reexecute();
 833   JVMState* youngest_jvms = should_reexecute ? sync_jvms_for_reexecute() : sync_jvms();
 834 
 835   // NOTE: set_bci (called from sync_jvms) might reset the reexecute bit to
 836   // undefined if the bci is different.  This is normal for Parse but it
 837   // should not happen for LibraryCallKit because only one bci is processed.
 838   assert(!is_LibraryCallKit() || (jvms()->should_reexecute() == should_reexecute),
 839          "in LibraryCallKit the reexecute bit should not change");
 840 
 841   // If we are guaranteed to throw, we can prune everything but the
 842   // input to the current bytecode.
 843   bool can_prune_locals = false;
 844   uint stack_slots_not_pruned = 0;
 845   int inputs = 0, depth = 0;
 846   if (must_throw) {
 847     assert(method() == youngest_jvms->method(), "sanity");
 848     if (compute_stack_effects(inputs, depth)) {
 849       can_prune_locals = true;
 850       stack_slots_not_pruned = inputs;
 851     }
 852   }
 853 
 854   if (env()->should_retain_local_variables()) {
 855     // At any safepoint, this method can get breakpointed, which would
 856     // then require an immediate deoptimization.
 857     can_prune_locals = false;  // do not prune locals
 858     stack_slots_not_pruned = 0;
 859   }
 860 
 861   C->add_safepoint_edges(call, youngest_jvms, can_prune_locals, stack_slots_not_pruned);
 862 }
 863 
 864 bool GraphKit::compute_stack_effects(int& inputs, int& depth) {
 865   Bytecodes::Code code = java_bc();
 866   if (code == Bytecodes::_wide) {
 867     code = method()->java_code_at_bci(bci() + 1);
 868   }
 869 
 870   BasicType rtype = T_ILLEGAL;
 871   int       rsize = 0;
 872 
 873   if (code != Bytecodes::_illegal) {
 874     depth = Bytecodes::depth(code); // checkcast=0, athrow=-1
 875     rtype = Bytecodes::result_type(code); // checkcast=P, athrow=V
 876     if (rtype < T_CONFLICT)
 877       rsize = type2size[rtype];
 878   }
 879 
 880   switch (code) {
 881   case Bytecodes::_illegal:
 882     return false;
 883 
 884   case Bytecodes::_ldc:
 885   case Bytecodes::_ldc_w:
 886   case Bytecodes::_ldc2_w:
 887     inputs = 0;
 888     break;
 889 
 890   case Bytecodes::_dup:         inputs = 1;  break;
 891   case Bytecodes::_dup_x1:      inputs = 2;  break;
 892   case Bytecodes::_dup_x2:      inputs = 3;  break;
 893   case Bytecodes::_dup2:        inputs = 2;  break;
 894   case Bytecodes::_dup2_x1:     inputs = 3;  break;
 895   case Bytecodes::_dup2_x2:     inputs = 4;  break;
 896   case Bytecodes::_swap:        inputs = 2;  break;
 897   case Bytecodes::_arraylength: inputs = 1;  break;
 898 
 899   case Bytecodes::_getstatic:
 900   case Bytecodes::_putstatic:
 901   case Bytecodes::_getfield:
 902   case Bytecodes::_vgetfield:
 903   case Bytecodes::_putfield:
 904     {
 905       bool ignored_will_link;
 906       ciField* field = method()->get_field_at_bci(bci(), ignored_will_link);
 907       int      size  = field->type()->size();
 908       bool is_get = (depth >= 0), is_static = (depth & 1);
 909       inputs = (is_static ? 0 : 1);
 910       if (is_get) {
 911         depth = size - inputs;
 912       } else {
 913         inputs += size;        // putxxx pops the value from the stack
 914         depth = - inputs;
 915       }
 916     }
 917     break;
 918 
 919   case Bytecodes::_invokevirtual:
 920   case Bytecodes::_invokespecial:
 921   case Bytecodes::_invokestatic:
 922   case Bytecodes::_invokedynamic:
 923   case Bytecodes::_invokeinterface:
 924     {
 925       bool ignored_will_link;
 926       ciSignature* declared_signature = NULL;
 927       ciMethod* ignored_callee = method()->get_method_at_bci(bci(), ignored_will_link, &declared_signature);
 928       assert(declared_signature != NULL, "cannot be null");
 929       inputs   = declared_signature->arg_size_for_bc(code);
 930       int size = declared_signature->return_type()->size();
 931       depth = size - inputs;
 932     }
 933     break;
 934 
 935   case Bytecodes::_multianewarray:
 936     {
 937       ciBytecodeStream iter(method());
 938       iter.reset_to_bci(bci());
 939       iter.next();
 940       inputs = iter.get_dimensions();
 941       assert(rsize == 1, "");
 942       depth = rsize - inputs;
 943     }
 944     break;
 945 
 946   case Bytecodes::_vwithfield: {
 947     bool ignored_will_link;
 948     ciField* field = method()->get_field_at_bci(bci(), ignored_will_link);
 949     int      size  = field->type()->size();
 950     inputs = size+1;
 951     depth = rsize - inputs;
 952     break;
 953   }
 954 
 955   case Bytecodes::_ireturn:
 956   case Bytecodes::_lreturn:
 957   case Bytecodes::_freturn:
 958   case Bytecodes::_dreturn:
 959   case Bytecodes::_areturn:
 960   case Bytecodes::_vreturn:
 961     assert(rsize == -depth, "");
 962     inputs = rsize;
 963     break;
 964 
 965   case Bytecodes::_jsr:
 966   case Bytecodes::_jsr_w:
 967     inputs = 0;
 968     depth  = 1;                  // S.B. depth=1, not zero
 969     break;
 970 
 971   default:
 972     // bytecode produces a typed result
 973     inputs = rsize - depth;
 974     assert(inputs >= 0, "");
 975     break;
 976   }
 977 
 978 #ifdef ASSERT
 979   // spot check
 980   int outputs = depth + inputs;
 981   assert(outputs >= 0, "sanity");
 982   switch (code) {
 983   case Bytecodes::_checkcast: assert(inputs == 1 && outputs == 1, ""); break;
 984   case Bytecodes::_athrow:    assert(inputs == 1 && outputs == 0, ""); break;
 985   case Bytecodes::_aload_0:   assert(inputs == 0 && outputs == 1, ""); break;
 986   case Bytecodes::_return:    assert(inputs == 0 && outputs == 0, ""); break;
 987   case Bytecodes::_drem:      assert(inputs == 4 && outputs == 2, ""); break;
 988   }
 989 #endif //ASSERT
 990 
 991   return true;
 992 }
 993 
 994 
 995 
 996 //------------------------------basic_plus_adr---------------------------------
 997 Node* GraphKit::basic_plus_adr(Node* base, Node* ptr, Node* offset) {
 998   // short-circuit a common case
 999   if (offset == intcon(0))  return ptr;
1000   return _gvn.transform( new AddPNode(base, ptr, offset) );
1001 }
1002 
1003 Node* GraphKit::ConvI2L(Node* offset) {
1004   // short-circuit a common case
1005   jint offset_con = find_int_con(offset, Type::OffsetBot);
1006   if (offset_con != Type::OffsetBot) {
1007     return longcon((jlong) offset_con);
1008   }
1009   return _gvn.transform( new ConvI2LNode(offset));
1010 }
1011 
1012 Node* GraphKit::ConvI2UL(Node* offset) {
1013   juint offset_con = (juint) find_int_con(offset, Type::OffsetBot);
1014   if (offset_con != (juint) Type::OffsetBot) {
1015     return longcon((julong) offset_con);
1016   }
1017   Node* conv = _gvn.transform( new ConvI2LNode(offset));
1018   Node* mask = _gvn.transform(ConLNode::make((julong) max_juint));
1019   return _gvn.transform( new AndLNode(conv, mask) );
1020 }
1021 
1022 Node* GraphKit::ConvL2I(Node* offset) {
1023   // short-circuit a common case
1024   jlong offset_con = find_long_con(offset, (jlong)Type::OffsetBot);
1025   if (offset_con != (jlong)Type::OffsetBot) {
1026     return intcon((int) offset_con);
1027   }
1028   return _gvn.transform( new ConvL2INode(offset));
1029 }
1030 
1031 //-------------------------load_object_klass-----------------------------------
1032 Node* GraphKit::load_object_klass(Node* obj) {
1033   // Special-case a fresh allocation to avoid building nodes:
1034   Node* akls = AllocateNode::Ideal_klass(obj, &_gvn);
1035   if (akls != NULL)  return akls;
1036   Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes());
1037   return _gvn.transform(LoadKlassNode::make(_gvn, NULL, immutable_memory(), k_adr, TypeInstPtr::KLASS));
1038 }
1039 
1040 //-------------------------load_array_length-----------------------------------
1041 Node* GraphKit::load_array_length(Node* array) {
1042   // Special-case a fresh allocation to avoid building nodes:
1043   AllocateArrayNode* alloc = AllocateArrayNode::Ideal_array_allocation(array, &_gvn);
1044   Node *alen;
1045   if (alloc == NULL) {
1046     Node *r_adr = basic_plus_adr(array, arrayOopDesc::length_offset_in_bytes());
1047     alen = _gvn.transform( new LoadRangeNode(0, immutable_memory(), r_adr, TypeInt::POS));
1048   } else {
1049     alen = alloc->Ideal_length();
1050     Node* ccast = alloc->make_ideal_length(_gvn.type(array)->is_oopptr(), &_gvn);
1051     if (ccast != alen) {
1052       alen = _gvn.transform(ccast);
1053     }
1054   }
1055   return alen;
1056 }
1057 
1058 //------------------------------do_null_check----------------------------------
1059 // Helper function to do a NULL pointer check.  Returned value is
1060 // the incoming address with NULL casted away.  You are allowed to use the
1061 // not-null value only if you are control dependent on the test.
1062 #ifndef PRODUCT
1063 extern int explicit_null_checks_inserted,
1064            explicit_null_checks_elided;
1065 #endif
1066 Node* GraphKit::null_check_common(Node* value, BasicType type,
1067                                   // optional arguments for variations:
1068                                   bool assert_null,
1069                                   Node* *null_control,
1070                                   bool speculative) {
1071   assert(!assert_null || null_control == NULL, "not both at once");
1072   if (stopped())  return top();
1073   NOT_PRODUCT(explicit_null_checks_inserted++);
1074 
1075   // Construct NULL check
1076   Node *chk = NULL;
1077   switch(type) {
1078     case T_LONG   : chk = new CmpLNode(value, _gvn.zerocon(T_LONG)); break;
1079     case T_INT    : chk = new CmpINode(value, _gvn.intcon(0)); break;
1080     case T_ARRAY  : // fall through
1081       type = T_OBJECT;  // simplify further tests
1082     case T_OBJECT : {
1083       const Type *t = _gvn.type( value );
1084 
1085       const TypeOopPtr* tp = t->isa_oopptr();
1086       if (tp != NULL && tp->klass() != NULL && !tp->klass()->is_loaded()
1087           // Only for do_null_check, not any of its siblings:
1088           && !assert_null && null_control == NULL) {
1089         // Usually, any field access or invocation on an unloaded oop type
1090         // will simply fail to link, since the statically linked class is
1091         // likely also to be unloaded.  However, in -Xcomp mode, sometimes
1092         // the static class is loaded but the sharper oop type is not.
1093         // Rather than checking for this obscure case in lots of places,
1094         // we simply observe that a null check on an unloaded class
1095         // will always be followed by a nonsense operation, so we
1096         // can just issue the uncommon trap here.
1097         // Our access to the unloaded class will only be correct
1098         // after it has been loaded and initialized, which requires
1099         // a trip through the interpreter.
1100 #ifndef PRODUCT
1101         if (WizardMode) { tty->print("Null check of unloaded "); tp->klass()->print(); tty->cr(); }
1102 #endif
1103         uncommon_trap(Deoptimization::Reason_unloaded,
1104                       Deoptimization::Action_reinterpret,
1105                       tp->klass(), "!loaded");
1106         return top();
1107       }
1108 
1109       if (assert_null) {
1110         // See if the type is contained in NULL_PTR.
1111         // If so, then the value is already null.
1112         if (t->higher_equal(TypePtr::NULL_PTR)) {
1113           NOT_PRODUCT(explicit_null_checks_elided++);
1114           return value;           // Elided null assert quickly!
1115         }
1116       } else {
1117         // See if mixing in the NULL pointer changes type.
1118         // If so, then the NULL pointer was not allowed in the original
1119         // type.  In other words, "value" was not-null.
1120         if (t->meet(TypePtr::NULL_PTR) != t->remove_speculative()) {
1121           // same as: if (!TypePtr::NULL_PTR->higher_equal(t)) ...
1122           NOT_PRODUCT(explicit_null_checks_elided++);
1123           return value;           // Elided null check quickly!
1124         }
1125       }
1126       chk = new CmpPNode( value, null() );
1127       break;
1128     }
1129 
1130     default:
1131       fatal("unexpected type: %s", type2name(type));
1132   }
1133   assert(chk != NULL, "sanity check");
1134   chk = _gvn.transform(chk);
1135 
1136   BoolTest::mask btest = assert_null ? BoolTest::eq : BoolTest::ne;
1137   BoolNode *btst = new BoolNode( chk, btest);
1138   Node   *tst = _gvn.transform( btst );
1139 
1140   //-----------
1141   // if peephole optimizations occurred, a prior test existed.
1142   // If a prior test existed, maybe it dominates as we can avoid this test.
1143   if (tst != btst && type == T_OBJECT) {
1144     // At this point we want to scan up the CFG to see if we can
1145     // find an identical test (and so avoid this test altogether).
1146     Node *cfg = control();
1147     int depth = 0;
1148     while( depth < 16 ) {       // Limit search depth for speed
1149       if( cfg->Opcode() == Op_IfTrue &&
1150           cfg->in(0)->in(1) == tst ) {
1151         // Found prior test.  Use "cast_not_null" to construct an identical
1152         // CastPP (and hence hash to) as already exists for the prior test.
1153         // Return that casted value.
1154         if (assert_null) {
1155           replace_in_map(value, null());
1156           return null();  // do not issue the redundant test
1157         }
1158         Node *oldcontrol = control();
1159         set_control(cfg);
1160         Node *res = cast_not_null(value);
1161         set_control(oldcontrol);
1162         NOT_PRODUCT(explicit_null_checks_elided++);
1163         return res;
1164       }
1165       cfg = IfNode::up_one_dom(cfg, /*linear_only=*/ true);
1166       if (cfg == NULL)  break;  // Quit at region nodes
1167       depth++;
1168     }
1169   }
1170 
1171   //-----------
1172   // Branch to failure if null
1173   float ok_prob = PROB_MAX;  // a priori estimate:  nulls never happen
1174   Deoptimization::DeoptReason reason;
1175   if (assert_null) {
1176     reason = Deoptimization::Reason_null_assert;
1177   } else if (type == T_OBJECT) {
1178     reason = Deoptimization::reason_null_check(speculative);
1179   } else {
1180     reason = Deoptimization::Reason_div0_check;
1181   }
1182   // %%% Since Reason_unhandled is not recorded on a per-bytecode basis,
1183   // ciMethodData::has_trap_at will return a conservative -1 if any
1184   // must-be-null assertion has failed.  This could cause performance
1185   // problems for a method after its first do_null_assert failure.
1186   // Consider using 'Reason_class_check' instead?
1187 
1188   // To cause an implicit null check, we set the not-null probability
1189   // to the maximum (PROB_MAX).  For an explicit check the probability
1190   // is set to a smaller value.
1191   if (null_control != NULL || too_many_traps(reason)) {
1192     // probability is less likely
1193     ok_prob =  PROB_LIKELY_MAG(3);
1194   } else if (!assert_null &&
1195              (ImplicitNullCheckThreshold > 0) &&
1196              method() != NULL &&
1197              (method()->method_data()->trap_count(reason)
1198               >= (uint)ImplicitNullCheckThreshold)) {
1199     ok_prob =  PROB_LIKELY_MAG(3);
1200   }
1201 
1202   if (null_control != NULL) {
1203     IfNode* iff = create_and_map_if(control(), tst, ok_prob, COUNT_UNKNOWN);
1204     Node* null_true = _gvn.transform( new IfFalseNode(iff));
1205     set_control(      _gvn.transform( new IfTrueNode(iff)));
1206 #ifndef PRODUCT
1207     if (null_true == top()) {
1208       explicit_null_checks_elided++;
1209     }
1210 #endif
1211     (*null_control) = null_true;
1212   } else {
1213     BuildCutout unless(this, tst, ok_prob);
1214     // Check for optimizer eliding test at parse time
1215     if (stopped()) {
1216       // Failure not possible; do not bother making uncommon trap.
1217       NOT_PRODUCT(explicit_null_checks_elided++);
1218     } else if (assert_null) {
1219       uncommon_trap(reason,
1220                     Deoptimization::Action_make_not_entrant,
1221                     NULL, "assert_null");
1222     } else {
1223       replace_in_map(value, zerocon(type));
1224       builtin_throw(reason);
1225     }
1226   }
1227 
1228   // Must throw exception, fall-thru not possible?
1229   if (stopped()) {
1230     return top();               // No result
1231   }
1232 
1233   if (assert_null) {
1234     // Cast obj to null on this path.
1235     replace_in_map(value, zerocon(type));
1236     return zerocon(type);
1237   }
1238 
1239   // Cast obj to not-null on this path, if there is no null_control.
1240   // (If there is a null_control, a non-null value may come back to haunt us.)
1241   if (type == T_OBJECT) {
1242     Node* cast = cast_not_null(value, false);
1243     if (null_control == NULL || (*null_control) == top())
1244       replace_in_map(value, cast);
1245     value = cast;
1246   }
1247 
1248   return value;
1249 }
1250 
1251 
1252 //------------------------------cast_not_null----------------------------------
1253 // Cast obj to not-null on this path
1254 Node* GraphKit::cast_not_null(Node* obj, bool do_replace_in_map) {
1255   const Type *t = _gvn.type(obj);
1256   const Type *t_not_null = t->join_speculative(TypePtr::NOTNULL);
1257   // Object is already not-null?
1258   if( t == t_not_null ) return obj;
1259 
1260   Node *cast = new CastPPNode(obj,t_not_null);
1261   cast->init_req(0, control());
1262   cast = _gvn.transform( cast );
1263 
1264   // Scan for instances of 'obj' in the current JVM mapping.
1265   // These instances are known to be not-null after the test.
1266   if (do_replace_in_map)
1267     replace_in_map(obj, cast);
1268 
1269   return cast;                  // Return casted value
1270 }
1271 
1272 
1273 //--------------------------replace_in_map-------------------------------------
1274 void GraphKit::replace_in_map(Node* old, Node* neww) {
1275   if (old == neww) {
1276     return;
1277   }
1278 
1279   map()->replace_edge(old, neww);
1280 
1281   // Note: This operation potentially replaces any edge
1282   // on the map.  This includes locals, stack, and monitors
1283   // of the current (innermost) JVM state.
1284 
1285   // don't let inconsistent types from profiling escape this
1286   // method
1287 
1288   const Type* told = _gvn.type(old);
1289   const Type* tnew = _gvn.type(neww);
1290 
1291   if (!tnew->higher_equal(told)) {
1292     return;
1293   }
1294 
1295   map()->record_replaced_node(old, neww);
1296 }
1297 
1298 
1299 //=============================================================================
1300 //--------------------------------memory---------------------------------------
1301 Node* GraphKit::memory(uint alias_idx) {
1302   MergeMemNode* mem = merged_memory();
1303   Node* p = mem->memory_at(alias_idx);
1304   _gvn.set_type(p, Type::MEMORY);  // must be mapped
1305   return p;
1306 }
1307 
1308 //-----------------------------reset_memory------------------------------------
1309 Node* GraphKit::reset_memory() {
1310   Node* mem = map()->memory();
1311   // do not use this node for any more parsing!
1312   debug_only( map()->set_memory((Node*)NULL) );
1313   return _gvn.transform( mem );
1314 }
1315 
1316 //------------------------------set_all_memory---------------------------------
1317 void GraphKit::set_all_memory(Node* newmem) {
1318   Node* mergemem = MergeMemNode::make(newmem);
1319   gvn().set_type_bottom(mergemem);
1320   map()->set_memory(mergemem);
1321 }
1322 
1323 //------------------------------set_all_memory_call----------------------------
1324 void GraphKit::set_all_memory_call(Node* call, bool separate_io_proj) {
1325   Node* newmem = _gvn.transform( new ProjNode(call, TypeFunc::Memory, separate_io_proj) );
1326   set_all_memory(newmem);
1327 }
1328 
1329 //=============================================================================
1330 //
1331 // parser factory methods for MemNodes
1332 //
1333 // These are layered on top of the factory methods in LoadNode and StoreNode,
1334 // and integrate with the parser's memory state and _gvn engine.
1335 //
1336 
1337 // factory methods in "int adr_idx"
1338 Node* GraphKit::make_load(Node* ctl, Node* adr, const Type* t, BasicType bt,
1339                           int adr_idx,
1340                           MemNode::MemOrd mo,
1341                           LoadNode::ControlDependency control_dependency,
1342                           bool require_atomic_access,
1343                           bool unaligned,
1344                           bool mismatched) {
1345   assert(adr_idx != Compile::AliasIdxTop, "use other make_load factory" );
1346   const TypePtr* adr_type = NULL; // debug-mode-only argument
1347   debug_only(adr_type = C->get_adr_type(adr_idx));
1348   Node* mem = memory(adr_idx);
1349   Node* ld;
1350   if (require_atomic_access && bt == T_LONG) {
1351     ld = LoadLNode::make_atomic(ctl, mem, adr, adr_type, t, mo, control_dependency, unaligned, mismatched);
1352   } else if (require_atomic_access && bt == T_DOUBLE) {
1353     ld = LoadDNode::make_atomic(ctl, mem, adr, adr_type, t, mo, control_dependency, unaligned, mismatched);
1354   } else {
1355     ld = LoadNode::make(_gvn, ctl, mem, adr, adr_type, t, bt, mo, control_dependency, unaligned, mismatched);
1356   }
1357   ld = _gvn.transform(ld);
1358 
1359   if (bt == T_VALUETYPE) {
1360     // Load value type from oop
1361     ld = ValueTypeNode::make(gvn(), map()->memory(), ld);
1362   } else if ((bt == T_OBJECT) && C->do_escape_analysis() || C->eliminate_boxing()) {
1363     // Improve graph before escape analysis and boxing elimination.
1364     record_for_igvn(ld);
1365   }
1366   return ld;
1367 }
1368 
1369 Node* GraphKit::store_to_memory(Node* ctl, Node* adr, Node *val, BasicType bt,
1370                                 int adr_idx,
1371                                 MemNode::MemOrd mo,
1372                                 bool require_atomic_access,
1373                                 bool unaligned,
1374                                 bool mismatched) {
1375   assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
1376   const TypePtr* adr_type = NULL;
1377   debug_only(adr_type = C->get_adr_type(adr_idx));
1378   Node *mem = memory(adr_idx);
1379   Node* st;
1380   if (require_atomic_access && bt == T_LONG) {
1381     st = StoreLNode::make_atomic(ctl, mem, adr, adr_type, val, mo);
1382   } else if (require_atomic_access && bt == T_DOUBLE) {
1383     st = StoreDNode::make_atomic(ctl, mem, adr, adr_type, val, mo);
1384   } else {
1385     st = StoreNode::make(_gvn, ctl, mem, adr, adr_type, val, bt, mo);
1386   }
1387   if (unaligned) {
1388     st->as_Store()->set_unaligned_access();
1389   }
1390   if (mismatched) {
1391     st->as_Store()->set_mismatched_access();
1392   }
1393   st = _gvn.transform(st);
1394   set_memory(st, adr_idx);
1395   // Back-to-back stores can only remove intermediate store with DU info
1396   // so push on worklist for optimizer.
1397   if (mem->req() > MemNode::Address && adr == mem->in(MemNode::Address))
1398     record_for_igvn(st);
1399 
1400   return st;
1401 }
1402 
1403 
1404 void GraphKit::pre_barrier(bool do_load,
1405                            Node* ctl,
1406                            Node* obj,
1407                            Node* adr,
1408                            uint  adr_idx,
1409                            Node* val,
1410                            const TypeOopPtr* val_type,
1411                            Node* pre_val,
1412                            BasicType bt) {
1413 
1414   BarrierSet* bs = Universe::heap()->barrier_set();
1415   set_control(ctl);
1416   switch (bs->kind()) {
1417     case BarrierSet::G1SATBCTLogging:
1418       g1_write_barrier_pre(do_load, obj, adr, adr_idx, val, val_type, pre_val, bt);
1419       break;
1420 
1421     case BarrierSet::CardTableForRS:
1422     case BarrierSet::CardTableExtension:
1423     case BarrierSet::ModRef:
1424       break;
1425 
1426     default      :
1427       ShouldNotReachHere();
1428 
1429   }
1430 }
1431 
1432 bool GraphKit::can_move_pre_barrier() const {
1433   BarrierSet* bs = Universe::heap()->barrier_set();
1434   switch (bs->kind()) {
1435     case BarrierSet::G1SATBCTLogging:
1436       return true; // Can move it if no safepoint
1437 
1438     case BarrierSet::CardTableForRS:
1439     case BarrierSet::CardTableExtension:
1440     case BarrierSet::ModRef:
1441       return true; // There is no pre-barrier
1442 
1443     default      :
1444       ShouldNotReachHere();
1445   }
1446   return false;
1447 }
1448 
1449 void GraphKit::post_barrier(Node* ctl,
1450                             Node* store,
1451                             Node* obj,
1452                             Node* adr,
1453                             uint  adr_idx,
1454                             Node* val,
1455                             BasicType bt,
1456                             bool use_precise) {
1457   BarrierSet* bs = Universe::heap()->barrier_set();
1458   set_control(ctl);
1459   switch (bs->kind()) {
1460     case BarrierSet::G1SATBCTLogging:
1461       g1_write_barrier_post(store, obj, adr, adr_idx, val, bt, use_precise);
1462       break;
1463 
1464     case BarrierSet::CardTableForRS:
1465     case BarrierSet::CardTableExtension:
1466       write_barrier_post(store, obj, adr, adr_idx, val, use_precise);
1467       break;
1468 
1469     case BarrierSet::ModRef:
1470       break;
1471 
1472     default      :
1473       ShouldNotReachHere();
1474 
1475   }
1476 }
1477 
1478 Node* GraphKit::store_oop(Node* ctl,
1479                           Node* obj,
1480                           Node* adr,
1481                           const TypePtr* adr_type,
1482                           Node* val,
1483                           const TypeOopPtr* val_type,
1484                           BasicType bt,
1485                           bool use_precise,
1486                           MemNode::MemOrd mo,
1487                           bool mismatched) {
1488   // Transformation of a value which could be NULL pointer (CastPP #NULL)
1489   // could be delayed during Parse (for example, in adjust_map_after_if()).
1490   // Execute transformation here to avoid barrier generation in such case.
1491   if (_gvn.type(val) == TypePtr::NULL_PTR)
1492     val = _gvn.makecon(TypePtr::NULL_PTR);
1493 
1494   set_control(ctl);
1495   if (stopped()) return top(); // Dead path ?
1496 
1497   assert(bt == T_OBJECT || bt == T_VALUETYPE, "sanity");
1498   assert(val != NULL, "not dead path");
1499   uint adr_idx = C->get_alias_index(adr_type);
1500   assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
1501 
1502   if (bt == T_VALUETYPE) {
1503     // Allocate value type and store oop
1504     val = val->as_ValueType()->store_to_memory(this);
1505   }
1506 
1507   pre_barrier(true /* do_load */,
1508               control(), obj, adr, adr_idx, val, val_type,
1509               NULL /* pre_val */,
1510               bt);
1511 
1512   Node* store = store_to_memory(control(), adr, val, bt, adr_idx, mo, mismatched);
1513   post_barrier(control(), store, obj, adr, adr_idx, val, bt, use_precise);
1514   return store;
1515 }
1516 
1517 // Could be an array or object we don't know at compile time (unsafe ref.)
1518 Node* GraphKit::store_oop_to_unknown(Node* ctl,
1519                              Node* obj,   // containing obj
1520                              Node* adr,  // actual adress to store val at
1521                              const TypePtr* adr_type,
1522                              Node* val,
1523                              BasicType bt,
1524                              MemNode::MemOrd mo,
1525                              bool mismatched) {
1526   Compile::AliasType* at = C->alias_type(adr_type);
1527   const TypeOopPtr* val_type = NULL;
1528   if (adr_type->isa_instptr()) {
1529     if (at->field() != NULL) {
1530       // known field.  This code is a copy of the do_put_xxx logic.
1531       ciField* field = at->field();
1532       if (!field->type()->is_loaded()) {
1533         val_type = TypeInstPtr::BOTTOM;
1534       } else {
1535         val_type = TypeOopPtr::make_from_klass(field->type()->as_klass());
1536       }
1537     }
1538   } else if (adr_type->isa_aryptr()) {
1539     val_type = adr_type->is_aryptr()->elem()->make_oopptr();
1540   }
1541   if (val_type == NULL) {
1542     val_type = TypeInstPtr::BOTTOM;
1543   }
1544   return store_oop(ctl, obj, adr, adr_type, val, val_type, bt, true, mo, mismatched);
1545 }
1546 
1547 
1548 //-------------------------array_element_address-------------------------
1549 Node* GraphKit::array_element_address(Node* ary, Node* idx, BasicType elembt,
1550                                       const TypeInt* sizetype, Node* ctrl) {
1551   uint shift  = exact_log2(type2aelembytes(elembt));
1552   ciKlass* arytype_klass = _gvn.type(ary)->is_aryptr()->klass();
1553   if (arytype_klass->is_value_array_klass()) {
1554     ciValueArrayKlass* vak = arytype_klass->as_value_array_klass();
1555     shift = vak->log2_element_size();
1556   }
1557   uint header = arrayOopDesc::base_offset_in_bytes(elembt);
1558 
1559   // short-circuit a common case (saves lots of confusing waste motion)
1560   jint idx_con = find_int_con(idx, -1);
1561   if (idx_con >= 0) {
1562     intptr_t offset = header + ((intptr_t)idx_con << shift);
1563     return basic_plus_adr(ary, offset);
1564   }
1565 
1566   // must be correct type for alignment purposes
1567   Node* base  = basic_plus_adr(ary, header);
1568   idx = Compile::conv_I2X_index(&_gvn, idx, sizetype, ctrl);
1569   Node* scale = _gvn.transform( new LShiftXNode(idx, intcon(shift)) );
1570   return basic_plus_adr(ary, base, scale);
1571 }
1572 
1573 //-------------------------load_array_element-------------------------
1574 Node* GraphKit::load_array_element(Node* ctl, Node* ary, Node* idx, const TypeAryPtr* arytype) {
1575   const Type* elemtype = arytype->elem();
1576   BasicType elembt = elemtype->array_element_basic_type();
1577   assert(elembt != T_VALUETYPE, "value types are not supported by this method");
1578   Node* adr = array_element_address(ary, idx, elembt, arytype->size());
1579   if (elembt == T_NARROWOOP) {
1580     elembt = T_OBJECT; // To satisfy switch in LoadNode::make()
1581   }
1582   Node* ld = make_load(ctl, adr, elemtype, elembt, arytype, MemNode::unordered);
1583   return ld;
1584 }
1585 
1586 //-------------------------set_arguments_for_java_call-------------------------
1587 // Arguments (pre-popped from the stack) are taken from the JVMS.
1588 void GraphKit::set_arguments_for_java_call(CallJavaNode* call) {
1589   // Add the call arguments:
1590   const TypeTuple* domain = call->tf()->domain_sig();
1591   uint nargs = domain->cnt();
1592   for (uint i = TypeFunc::Parms, idx = TypeFunc::Parms; i < nargs; i++) {
1593     Node* arg = argument(i-TypeFunc::Parms);
1594     if (ValueTypePassFieldsAsArgs) {
1595       if (arg->is_ValueType()) {
1596         ValueTypeNode* vt = arg->as_ValueType();
1597         if (domain->field_at(i)->is_valuetypeptr()->klass() != C->env()->___Value_klass()) {
1598           // We don't pass value type arguments by reference but instead
1599           // pass each field of the value type
1600           idx += vt->pass_fields(call, idx, *this);
1601         } else {
1602           arg = arg->as_ValueType()->store_to_memory(this);
1603           call->init_req(idx, arg);
1604           idx++;
1605         }
1606         // If a value type argument is passed as fields, attach the Method* to the call site
1607         // to be able to access the extended signature later via attached_method_before_pc().
1608         // For example, see CompiledMethod::preserve_callee_argument_oops().
1609         call->set_override_symbolic_info(true);
1610       } else {
1611         call->init_req(idx, arg);
1612         idx++;
1613       }
1614     } else {
1615       if (arg->is_ValueType()) {
1616         // Pass value type argument via oop to callee
1617         arg = arg->as_ValueType()->store_to_memory(this);
1618       }
1619       call->init_req(i, arg);
1620     }
1621   }
1622 }
1623 
1624 //---------------------------set_edges_for_java_call---------------------------
1625 // Connect a newly created call into the current JVMS.
1626 // A return value node (if any) is returned from set_edges_for_java_call.
1627 void GraphKit::set_edges_for_java_call(CallJavaNode* call, bool must_throw, bool separate_io_proj) {
1628 
1629   // Add the predefined inputs:
1630   call->init_req( TypeFunc::Control, control() );
1631   call->init_req( TypeFunc::I_O    , i_o() );
1632   call->init_req( TypeFunc::Memory , reset_memory() );
1633   call->init_req( TypeFunc::FramePtr, frameptr() );
1634   call->init_req( TypeFunc::ReturnAdr, top() );
1635 
1636   add_safepoint_edges(call, must_throw);
1637 
1638   Node* xcall = _gvn.transform(call);
1639 
1640   if (xcall == top()) {
1641     set_control(top());
1642     return;
1643   }
1644   assert(xcall == call, "call identity is stable");
1645 
1646   // Re-use the current map to produce the result.
1647 
1648   set_control(_gvn.transform(new ProjNode(call, TypeFunc::Control)));
1649   set_i_o(    _gvn.transform(new ProjNode(call, TypeFunc::I_O    , separate_io_proj)));
1650   set_all_memory_call(xcall, separate_io_proj);
1651 
1652   //return xcall;   // no need, caller already has it
1653 }
1654 
1655 Node* GraphKit::set_results_for_java_call(CallJavaNode* call, bool separate_io_proj) {
1656   if (stopped())  return top();  // maybe the call folded up?
1657 
1658   // Capture the return value, if any.
1659   Node* ret;
1660   if (call->method() == NULL ||
1661       call->method()->return_type()->basic_type() == T_VOID)
1662         ret = top();
1663   else {
1664     if (!call->tf()->returns_value_type_as_fields()) {
1665       ret = _gvn.transform(new ProjNode(call, TypeFunc::Parms));
1666     } else {
1667       // Return of multiple values (value type fields): we create a
1668       // ValueType node, each field is a projection from the call.
1669       const TypeTuple *range_sig = call->tf()->range_sig();
1670       const Type* t = range_sig->field_at(TypeFunc::Parms);
1671       assert(t->isa_valuetypeptr(), "only value types for multiple return values");
1672       ciValueKlass* vk = t->is_valuetypeptr()->value_type()->value_klass();
1673       ret = C->create_vt_node(call, vk, vk, 0, TypeFunc::Parms+1, false);
1674     }
1675   }
1676 
1677   // Note:  Since any out-of-line call can produce an exception,
1678   // we always insert an I_O projection from the call into the result.
1679 
1680   make_slow_call_ex(call, env()->Throwable_klass(), separate_io_proj);
1681 
1682   if (separate_io_proj) {
1683     // The caller requested separate projections be used by the fall
1684     // through and exceptional paths, so replace the projections for
1685     // the fall through path.
1686     set_i_o(_gvn.transform( new ProjNode(call, TypeFunc::I_O) ));
1687     set_all_memory(_gvn.transform( new ProjNode(call, TypeFunc::Memory) ));
1688   }
1689   return ret;
1690 }
1691 
1692 //--------------------set_predefined_input_for_runtime_call--------------------
1693 // Reading and setting the memory state is way conservative here.
1694 // The real problem is that I am not doing real Type analysis on memory,
1695 // so I cannot distinguish card mark stores from other stores.  Across a GC
1696 // point the Store Barrier and the card mark memory has to agree.  I cannot
1697 // have a card mark store and its barrier split across the GC point from
1698 // either above or below.  Here I get that to happen by reading ALL of memory.
1699 // A better answer would be to separate out card marks from other memory.
1700 // For now, return the input memory state, so that it can be reused
1701 // after the call, if this call has restricted memory effects.
1702 Node* GraphKit::set_predefined_input_for_runtime_call(SafePointNode* call) {
1703   // Set fixed predefined input arguments
1704   Node* memory = reset_memory();
1705   call->init_req( TypeFunc::Control,   control()  );
1706   call->init_req( TypeFunc::I_O,       top()      ); // does no i/o
1707   call->init_req( TypeFunc::Memory,    memory     ); // may gc ptrs
1708   call->init_req( TypeFunc::FramePtr,  frameptr() );
1709   call->init_req( TypeFunc::ReturnAdr, top()      );
1710   return memory;
1711 }
1712 
1713 //-------------------set_predefined_output_for_runtime_call--------------------
1714 // Set control and memory (not i_o) from the call.
1715 // If keep_mem is not NULL, use it for the output state,
1716 // except for the RawPtr output of the call, if hook_mem is TypeRawPtr::BOTTOM.
1717 // If hook_mem is NULL, this call produces no memory effects at all.
1718 // If hook_mem is a Java-visible memory slice (such as arraycopy operands),
1719 // then only that memory slice is taken from the call.
1720 // In the last case, we must put an appropriate memory barrier before
1721 // the call, so as to create the correct anti-dependencies on loads
1722 // preceding the call.
1723 void GraphKit::set_predefined_output_for_runtime_call(Node* call,
1724                                                       Node* keep_mem,
1725                                                       const TypePtr* hook_mem) {
1726   // no i/o
1727   set_control(_gvn.transform( new ProjNode(call,TypeFunc::Control) ));
1728   if (keep_mem) {
1729     // First clone the existing memory state
1730     set_all_memory(keep_mem);
1731     if (hook_mem != NULL) {
1732       // Make memory for the call
1733       Node* mem = _gvn.transform( new ProjNode(call, TypeFunc::Memory) );
1734       // Set the RawPtr memory state only.  This covers all the heap top/GC stuff
1735       // We also use hook_mem to extract specific effects from arraycopy stubs.
1736       set_memory(mem, hook_mem);
1737     }
1738     // ...else the call has NO memory effects.
1739 
1740     // Make sure the call advertises its memory effects precisely.
1741     // This lets us build accurate anti-dependences in gcm.cpp.
1742     assert(C->alias_type(call->adr_type()) == C->alias_type(hook_mem),
1743            "call node must be constructed correctly");
1744   } else {
1745     assert(hook_mem == NULL, "");
1746     // This is not a "slow path" call; all memory comes from the call.
1747     set_all_memory_call(call);
1748   }
1749 }
1750 
1751 
1752 // Replace the call with the current state of the kit.
1753 void GraphKit::replace_call(CallNode* call, Node* result, bool do_replaced_nodes) {
1754   JVMState* ejvms = NULL;
1755   if (has_exceptions()) {
1756     ejvms = transfer_exceptions_into_jvms();
1757   }
1758 
1759   ReplacedNodes replaced_nodes = map()->replaced_nodes();
1760   ReplacedNodes replaced_nodes_exception;
1761   Node* ex_ctl = top();
1762 
1763   SafePointNode* final_state = stop();
1764 
1765   // Find all the needed outputs of this call
1766   CallProjections callprojs;
1767   call->extract_projections(&callprojs, true);
1768 
1769   Node* init_mem = call->in(TypeFunc::Memory);
1770   Node* final_mem = final_state->in(TypeFunc::Memory);
1771   Node* final_ctl = final_state->in(TypeFunc::Control);
1772   Node* final_io = final_state->in(TypeFunc::I_O);
1773 
1774   // Replace all the old call edges with the edges from the inlining result
1775   if (callprojs.fallthrough_catchproj != NULL) {
1776     C->gvn_replace_by(callprojs.fallthrough_catchproj, final_ctl);
1777   }
1778   if (callprojs.fallthrough_memproj != NULL) {
1779     if (final_mem->is_MergeMem()) {
1780       // Parser's exits MergeMem was not transformed but may be optimized
1781       final_mem = _gvn.transform(final_mem);
1782     }
1783     C->gvn_replace_by(callprojs.fallthrough_memproj,   final_mem);
1784   }
1785   if (callprojs.fallthrough_ioproj != NULL) {
1786     C->gvn_replace_by(callprojs.fallthrough_ioproj,    final_io);
1787   }
1788 
1789   // Replace the result with the new result if it exists and is used
1790   if (callprojs.resproj != NULL && result != NULL) {
1791     C->gvn_replace_by(callprojs.resproj, result);
1792   }
1793 
1794   if (ejvms == NULL) {
1795     // No exception edges to simply kill off those paths
1796     if (callprojs.catchall_catchproj != NULL) {
1797       C->gvn_replace_by(callprojs.catchall_catchproj, C->top());
1798     }
1799     if (callprojs.catchall_memproj != NULL) {
1800       C->gvn_replace_by(callprojs.catchall_memproj,   C->top());
1801     }
1802     if (callprojs.catchall_ioproj != NULL) {
1803       C->gvn_replace_by(callprojs.catchall_ioproj,    C->top());
1804     }
1805     // Replace the old exception object with top
1806     if (callprojs.exobj != NULL) {
1807       C->gvn_replace_by(callprojs.exobj, C->top());
1808     }
1809   } else {
1810     GraphKit ekit(ejvms);
1811 
1812     // Load my combined exception state into the kit, with all phis transformed:
1813     SafePointNode* ex_map = ekit.combine_and_pop_all_exception_states();
1814     replaced_nodes_exception = ex_map->replaced_nodes();
1815 
1816     Node* ex_oop = ekit.use_exception_state(ex_map);
1817 
1818     if (callprojs.catchall_catchproj != NULL) {
1819       C->gvn_replace_by(callprojs.catchall_catchproj, ekit.control());
1820       ex_ctl = ekit.control();
1821     }
1822     if (callprojs.catchall_memproj != NULL) {
1823       C->gvn_replace_by(callprojs.catchall_memproj,   ekit.reset_memory());
1824     }
1825     if (callprojs.catchall_ioproj != NULL) {
1826       C->gvn_replace_by(callprojs.catchall_ioproj,    ekit.i_o());
1827     }
1828 
1829     // Replace the old exception object with the newly created one
1830     if (callprojs.exobj != NULL) {
1831       C->gvn_replace_by(callprojs.exobj, ex_oop);
1832     }
1833   }
1834 
1835   // Disconnect the call from the graph
1836   call->disconnect_inputs(NULL, C);
1837   C->gvn_replace_by(call, C->top());
1838 
1839   // Clean up any MergeMems that feed other MergeMems since the
1840   // optimizer doesn't like that.
1841   if (final_mem->is_MergeMem()) {
1842     Node_List wl;
1843     for (SimpleDUIterator i(final_mem); i.has_next(); i.next()) {
1844       Node* m = i.get();
1845       if (m->is_MergeMem() && !wl.contains(m)) {
1846         wl.push(m);
1847       }
1848     }
1849     while (wl.size()  > 0) {
1850       _gvn.transform(wl.pop());
1851     }
1852   }
1853 
1854   if (callprojs.fallthrough_catchproj != NULL && !final_ctl->is_top() && do_replaced_nodes) {
1855     replaced_nodes.apply(C, final_ctl);
1856   }
1857   if (!ex_ctl->is_top() && do_replaced_nodes) {
1858     replaced_nodes_exception.apply(C, ex_ctl);
1859   }
1860 }
1861 
1862 
1863 //------------------------------increment_counter------------------------------
1864 // for statistics: increment a VM counter by 1
1865 
1866 void GraphKit::increment_counter(address counter_addr) {
1867   Node* adr1 = makecon(TypeRawPtr::make(counter_addr));
1868   increment_counter(adr1);
1869 }
1870 
1871 void GraphKit::increment_counter(Node* counter_addr) {
1872   int adr_type = Compile::AliasIdxRaw;
1873   Node* ctrl = control();
1874   Node* cnt  = make_load(ctrl, counter_addr, TypeInt::INT, T_INT, adr_type, MemNode::unordered);
1875   Node* incr = _gvn.transform(new AddINode(cnt, _gvn.intcon(1)));
1876   store_to_memory(ctrl, counter_addr, incr, T_INT, adr_type, MemNode::unordered);
1877 }
1878 
1879 
1880 //------------------------------uncommon_trap----------------------------------
1881 // Bail out to the interpreter in mid-method.  Implemented by calling the
1882 // uncommon_trap blob.  This helper function inserts a runtime call with the
1883 // right debug info.
1884 void GraphKit::uncommon_trap(int trap_request,
1885                              ciKlass* klass, const char* comment,
1886                              bool must_throw,
1887                              bool keep_exact_action) {
1888   if (failing())  stop();
1889   if (stopped())  return; // trap reachable?
1890 
1891   // Note:  If ProfileTraps is true, and if a deopt. actually
1892   // occurs here, the runtime will make sure an MDO exists.  There is
1893   // no need to call method()->ensure_method_data() at this point.
1894 
1895   // Set the stack pointer to the right value for reexecution:
1896   set_sp(reexecute_sp());
1897 
1898 #ifdef ASSERT
1899   if (!must_throw) {
1900     // Make sure the stack has at least enough depth to execute
1901     // the current bytecode.
1902     int inputs, ignored_depth;
1903     if (compute_stack_effects(inputs, ignored_depth)) {
1904       assert(sp() >= inputs, "must have enough JVMS stack to execute %s: sp=%d, inputs=%d",
1905              Bytecodes::name(java_bc()), sp(), inputs);
1906     }
1907   }
1908 #endif
1909 
1910   Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(trap_request);
1911   Deoptimization::DeoptAction action = Deoptimization::trap_request_action(trap_request);
1912 
1913   switch (action) {
1914   case Deoptimization::Action_maybe_recompile:
1915   case Deoptimization::Action_reinterpret:
1916     // Temporary fix for 6529811 to allow virtual calls to be sure they
1917     // get the chance to go from mono->bi->mega
1918     if (!keep_exact_action &&
1919         Deoptimization::trap_request_index(trap_request) < 0 &&
1920         too_many_recompiles(reason)) {
1921       // This BCI is causing too many recompilations.
1922       if (C->log() != NULL) {
1923         C->log()->elem("observe that='trap_action_change' reason='%s' from='%s' to='none'",
1924                 Deoptimization::trap_reason_name(reason),
1925                 Deoptimization::trap_action_name(action));
1926       }
1927       action = Deoptimization::Action_none;
1928       trap_request = Deoptimization::make_trap_request(reason, action);
1929     } else {
1930       C->set_trap_can_recompile(true);
1931     }
1932     break;
1933   case Deoptimization::Action_make_not_entrant:
1934     C->set_trap_can_recompile(true);
1935     break;
1936 #ifdef ASSERT
1937   case Deoptimization::Action_none:
1938   case Deoptimization::Action_make_not_compilable:
1939     break;
1940   default:
1941     fatal("unknown action %d: %s", action, Deoptimization::trap_action_name(action));
1942     break;
1943 #endif
1944   }
1945 
1946   if (TraceOptoParse) {
1947     char buf[100];
1948     tty->print_cr("Uncommon trap %s at bci:%d",
1949                   Deoptimization::format_trap_request(buf, sizeof(buf),
1950                                                       trap_request), bci());
1951   }
1952 
1953   CompileLog* log = C->log();
1954   if (log != NULL) {
1955     int kid = (klass == NULL)? -1: log->identify(klass);
1956     log->begin_elem("uncommon_trap bci='%d'", bci());
1957     char buf[100];
1958     log->print(" %s", Deoptimization::format_trap_request(buf, sizeof(buf),
1959                                                           trap_request));
1960     if (kid >= 0)         log->print(" klass='%d'", kid);
1961     if (comment != NULL)  log->print(" comment='%s'", comment);
1962     log->end_elem();
1963   }
1964 
1965   // Make sure any guarding test views this path as very unlikely
1966   Node *i0 = control()->in(0);
1967   if (i0 != NULL && i0->is_If()) {        // Found a guarding if test?
1968     IfNode *iff = i0->as_If();
1969     float f = iff->_prob;   // Get prob
1970     if (control()->Opcode() == Op_IfTrue) {
1971       if (f > PROB_UNLIKELY_MAG(4))
1972         iff->_prob = PROB_MIN;
1973     } else {
1974       if (f < PROB_LIKELY_MAG(4))
1975         iff->_prob = PROB_MAX;
1976     }
1977   }
1978 
1979   // Clear out dead values from the debug info.
1980   kill_dead_locals();
1981 
1982   // Now insert the uncommon trap subroutine call
1983   address call_addr = SharedRuntime::uncommon_trap_blob()->entry_point();
1984   const TypePtr* no_memory_effects = NULL;
1985   // Pass the index of the class to be loaded
1986   Node* call = make_runtime_call(RC_NO_LEAF | RC_UNCOMMON |
1987                                  (must_throw ? RC_MUST_THROW : 0),
1988                                  OptoRuntime::uncommon_trap_Type(),
1989                                  call_addr, "uncommon_trap", no_memory_effects,
1990                                  intcon(trap_request));
1991   assert(call->as_CallStaticJava()->uncommon_trap_request() == trap_request,
1992          "must extract request correctly from the graph");
1993   assert(trap_request != 0, "zero value reserved by uncommon_trap_request");
1994 
1995   call->set_req(TypeFunc::ReturnAdr, returnadr());
1996   // The debug info is the only real input to this call.
1997 
1998   // Halt-and-catch fire here.  The above call should never return!
1999   HaltNode* halt = new HaltNode(control(), frameptr());
2000   _gvn.set_type_bottom(halt);
2001   root()->add_req(halt);
2002 
2003   stop_and_kill_map();
2004 }
2005 
2006 
2007 //--------------------------just_allocated_object------------------------------
2008 // Report the object that was just allocated.
2009 // It must be the case that there are no intervening safepoints.
2010 // We use this to determine if an object is so "fresh" that
2011 // it does not require card marks.
2012 Node* GraphKit::just_allocated_object(Node* current_control) {
2013   if (C->recent_alloc_ctl() == current_control)
2014     return C->recent_alloc_obj();
2015   return NULL;
2016 }
2017 
2018 
2019 void GraphKit::round_double_arguments(ciMethod* dest_method) {
2020   // (Note:  TypeFunc::make has a cache that makes this fast.)
2021   const TypeFunc* tf    = TypeFunc::make(dest_method);
2022   int             nargs = tf->domain_sig()->cnt() - TypeFunc::Parms;
2023   for (int j = 0; j < nargs; j++) {
2024     const Type *targ = tf->domain_sig()->field_at(j + TypeFunc::Parms);
2025     if( targ->basic_type() == T_DOUBLE ) {
2026       // If any parameters are doubles, they must be rounded before
2027       // the call, dstore_rounding does gvn.transform
2028       Node *arg = argument(j);
2029       arg = dstore_rounding(arg);
2030       set_argument(j, arg);
2031     }
2032   }
2033 }
2034 
2035 /**
2036  * Record profiling data exact_kls for Node n with the type system so
2037  * that it can propagate it (speculation)
2038  *
2039  * @param n          node that the type applies to
2040  * @param exact_kls  type from profiling
2041  * @param maybe_null did profiling see null?
2042  *
2043  * @return           node with improved type
2044  */
2045 Node* GraphKit::record_profile_for_speculation(Node* n, ciKlass* exact_kls, bool maybe_null) {
2046   const Type* current_type = _gvn.type(n);
2047   assert(UseTypeSpeculation, "type speculation must be on");
2048 
2049   const TypePtr* speculative = current_type->speculative();
2050 
2051   // Should the klass from the profile be recorded in the speculative type?
2052   if (current_type->would_improve_type(exact_kls, jvms()->depth())) {
2053     const TypeKlassPtr* tklass = TypeKlassPtr::make(exact_kls);
2054     const TypeOopPtr* xtype = tklass->as_instance_type();
2055     assert(xtype->klass_is_exact(), "Should be exact");
2056     // Any reason to believe n is not null (from this profiling or a previous one)?
2057     const TypePtr* ptr = (maybe_null && current_type->speculative_maybe_null()) ? TypePtr::BOTTOM : TypePtr::NOTNULL;
2058     // record the new speculative type's depth
2059     speculative = xtype->cast_to_ptr_type(ptr->ptr())->is_ptr();
2060     speculative = speculative->with_inline_depth(jvms()->depth());
2061   } else if (current_type->would_improve_ptr(maybe_null)) {
2062     // Profiling report that null was never seen so we can change the
2063     // speculative type to non null ptr.
2064     assert(!maybe_null, "nothing to improve");
2065     if (speculative == NULL) {
2066       speculative = TypePtr::NOTNULL;
2067     } else {
2068       const TypePtr* ptr = TypePtr::NOTNULL;
2069       speculative = speculative->cast_to_ptr_type(ptr->ptr())->is_ptr();
2070     }
2071   }
2072 
2073   if (speculative != current_type->speculative()) {
2074     // Build a type with a speculative type (what we think we know
2075     // about the type but will need a guard when we use it)
2076     const TypeOopPtr* spec_type = TypeOopPtr::make(TypePtr::BotPTR, Type::Offset::bottom, TypeOopPtr::InstanceBot, speculative);
2077     // We're changing the type, we need a new CheckCast node to carry
2078     // the new type. The new type depends on the control: what
2079     // profiling tells us is only valid from here as far as we can
2080     // tell.
2081     Node* cast = new CheckCastPPNode(control(), n, current_type->remove_speculative()->join_speculative(spec_type));
2082     cast = _gvn.transform(cast);
2083     replace_in_map(n, cast);
2084     n = cast;
2085   }
2086 
2087   return n;
2088 }
2089 
2090 /**
2091  * Record profiling data from receiver profiling at an invoke with the
2092  * type system so that it can propagate it (speculation)
2093  *
2094  * @param n  receiver node
2095  *
2096  * @return   node with improved type
2097  */
2098 Node* GraphKit::record_profiled_receiver_for_speculation(Node* n) {
2099   if (!UseTypeSpeculation) {
2100     return n;
2101   }
2102   ciKlass* exact_kls = profile_has_unique_klass();
2103   bool maybe_null = true;
2104   if (java_bc() == Bytecodes::_checkcast ||
2105       java_bc() == Bytecodes::_instanceof ||
2106       java_bc() == Bytecodes::_aastore) {
2107     ciProfileData* data = method()->method_data()->bci_to_data(bci());
2108     maybe_null = data == NULL ? true : data->as_BitData()->null_seen();
2109   }
2110   return record_profile_for_speculation(n, exact_kls, maybe_null);
2111 }
2112 
2113 /**
2114  * Record profiling data from argument profiling at an invoke with the
2115  * type system so that it can propagate it (speculation)
2116  *
2117  * @param dest_method  target method for the call
2118  * @param bc           what invoke bytecode is this?
2119  */
2120 void GraphKit::record_profiled_arguments_for_speculation(ciMethod* dest_method, Bytecodes::Code bc) {
2121   if (!UseTypeSpeculation) {
2122     return;
2123   }
2124   const TypeFunc* tf    = TypeFunc::make(dest_method);
2125   int             nargs = tf->domain_sig()->cnt() - TypeFunc::Parms;
2126   int skip = Bytecodes::has_receiver(bc) ? 1 : 0;
2127   for (int j = skip, i = 0; j < nargs && i < TypeProfileArgsLimit; j++) {
2128     const Type *targ = tf->domain_sig()->field_at(j + TypeFunc::Parms);
2129     if (targ->basic_type() == T_OBJECT || targ->basic_type() == T_ARRAY) {
2130       bool maybe_null = true;
2131       ciKlass* better_type = NULL;
2132       if (method()->argument_profiled_type(bci(), i, better_type, maybe_null)) {
2133         record_profile_for_speculation(argument(j), better_type, maybe_null);
2134       }
2135       i++;
2136     }
2137   }
2138 }
2139 
2140 /**
2141  * Record profiling data from parameter profiling at an invoke with
2142  * the type system so that it can propagate it (speculation)
2143  */
2144 void GraphKit::record_profiled_parameters_for_speculation() {
2145   if (!UseTypeSpeculation) {
2146     return;
2147   }
2148   for (int i = 0, j = 0; i < method()->arg_size() ; i++) {
2149     if (_gvn.type(local(i))->isa_oopptr()) {
2150       bool maybe_null = true;
2151       ciKlass* better_type = NULL;
2152       if (method()->parameter_profiled_type(j, better_type, maybe_null)) {
2153         record_profile_for_speculation(local(i), better_type, maybe_null);
2154       }
2155       j++;
2156     }
2157   }
2158 }
2159 
2160 /**
2161  * Record profiling data from return value profiling at an invoke with
2162  * the type system so that it can propagate it (speculation)
2163  */
2164 void GraphKit::record_profiled_return_for_speculation() {
2165   if (!UseTypeSpeculation) {
2166     return;
2167   }
2168   bool maybe_null = true;
2169   ciKlass* better_type = NULL;
2170   if (method()->return_profiled_type(bci(), better_type, maybe_null)) {
2171     // If profiling reports a single type for the return value,
2172     // feed it to the type system so it can propagate it as a
2173     // speculative type
2174     record_profile_for_speculation(stack(sp()-1), better_type, maybe_null);
2175   }
2176 }
2177 
2178 void GraphKit::round_double_result(ciMethod* dest_method) {
2179   // A non-strict method may return a double value which has an extended
2180   // exponent, but this must not be visible in a caller which is 'strict'
2181   // If a strict caller invokes a non-strict callee, round a double result
2182 
2183   BasicType result_type = dest_method->return_type()->basic_type();
2184   assert( method() != NULL, "must have caller context");
2185   if( result_type == T_DOUBLE && method()->is_strict() && !dest_method->is_strict() ) {
2186     // Destination method's return value is on top of stack
2187     // dstore_rounding() does gvn.transform
2188     Node *result = pop_pair();
2189     result = dstore_rounding(result);
2190     push_pair(result);
2191   }
2192 }
2193 
2194 // rounding for strict float precision conformance
2195 Node* GraphKit::precision_rounding(Node* n) {
2196   return UseStrictFP && _method->flags().is_strict()
2197     && UseSSE == 0 && Matcher::strict_fp_requires_explicit_rounding
2198     ? _gvn.transform( new RoundFloatNode(0, n) )
2199     : n;
2200 }
2201 
2202 // rounding for strict double precision conformance
2203 Node* GraphKit::dprecision_rounding(Node *n) {
2204   return UseStrictFP && _method->flags().is_strict()
2205     && UseSSE <= 1 && Matcher::strict_fp_requires_explicit_rounding
2206     ? _gvn.transform( new RoundDoubleNode(0, n) )
2207     : n;
2208 }
2209 
2210 // rounding for non-strict double stores
2211 Node* GraphKit::dstore_rounding(Node* n) {
2212   return Matcher::strict_fp_requires_explicit_rounding
2213     && UseSSE <= 1
2214     ? _gvn.transform( new RoundDoubleNode(0, n) )
2215     : n;
2216 }
2217 
2218 //=============================================================================
2219 // Generate a fast path/slow path idiom.  Graph looks like:
2220 // [foo] indicates that 'foo' is a parameter
2221 //
2222 //              [in]     NULL
2223 //                 \    /
2224 //                  CmpP
2225 //                  Bool ne
2226 //                   If
2227 //                  /  \
2228 //              True    False-<2>
2229 //              / |
2230 //             /  cast_not_null
2231 //           Load  |    |   ^
2232 //        [fast_test]   |   |
2233 // gvn to   opt_test    |   |
2234 //          /    \      |  <1>
2235 //      True     False  |
2236 //        |         \\  |
2237 //   [slow_call]     \[fast_result]
2238 //    Ctl   Val       \      \
2239 //     |               \      \
2240 //    Catch       <1>   \      \
2241 //   /    \        ^     \      \
2242 //  Ex    No_Ex    |      \      \
2243 //  |       \   \  |       \ <2>  \
2244 //  ...      \  [slow_res] |  |    \   [null_result]
2245 //            \         \--+--+---  |  |
2246 //             \           | /    \ | /
2247 //              --------Region     Phi
2248 //
2249 //=============================================================================
2250 // Code is structured as a series of driver functions all called 'do_XXX' that
2251 // call a set of helper functions.  Helper functions first, then drivers.
2252 
2253 //------------------------------null_check_oop---------------------------------
2254 // Null check oop.  Set null-path control into Region in slot 3.
2255 // Make a cast-not-nullness use the other not-null control.  Return cast.
2256 Node* GraphKit::null_check_oop(Node* value, Node* *null_control,
2257                                bool never_see_null,
2258                                bool safe_for_replace,
2259                                bool speculative) {
2260   // Initial NULL check taken path
2261   (*null_control) = top();
2262   Node* cast = null_check_common(value, T_OBJECT, false, null_control, speculative);
2263 
2264   // Generate uncommon_trap:
2265   if (never_see_null && (*null_control) != top()) {
2266     // If we see an unexpected null at a check-cast we record it and force a
2267     // recompile; the offending check-cast will be compiled to handle NULLs.
2268     // If we see more than one offending BCI, then all checkcasts in the
2269     // method will be compiled to handle NULLs.
2270     PreserveJVMState pjvms(this);
2271     set_control(*null_control);
2272     replace_in_map(value, null());
2273     Deoptimization::DeoptReason reason = Deoptimization::reason_null_check(speculative);
2274     uncommon_trap(reason,
2275                   Deoptimization::Action_make_not_entrant);
2276     (*null_control) = top();    // NULL path is dead
2277   }
2278   if ((*null_control) == top() && safe_for_replace) {
2279     replace_in_map(value, cast);
2280   }
2281 
2282   // Cast away null-ness on the result
2283   return cast;
2284 }
2285 
2286 //------------------------------opt_iff----------------------------------------
2287 // Optimize the fast-check IfNode.  Set the fast-path region slot 2.
2288 // Return slow-path control.
2289 Node* GraphKit::opt_iff(Node* region, Node* iff) {
2290   IfNode *opt_iff = _gvn.transform(iff)->as_If();
2291 
2292   // Fast path taken; set region slot 2
2293   Node *fast_taken = _gvn.transform( new IfFalseNode(opt_iff) );
2294   region->init_req(2,fast_taken); // Capture fast-control
2295 
2296   // Fast path not-taken, i.e. slow path
2297   Node *slow_taken = _gvn.transform( new IfTrueNode(opt_iff) );
2298   return slow_taken;
2299 }
2300 
2301 //-----------------------------make_runtime_call-------------------------------
2302 Node* GraphKit::make_runtime_call(int flags,
2303                                   const TypeFunc* call_type, address call_addr,
2304                                   const char* call_name,
2305                                   const TypePtr* adr_type,
2306                                   // The following parms are all optional.
2307                                   // The first NULL ends the list.
2308                                   Node* parm0, Node* parm1,
2309                                   Node* parm2, Node* parm3,
2310                                   Node* parm4, Node* parm5,
2311                                   Node* parm6, Node* parm7) {
2312   // Slow-path call
2313   bool is_leaf = !(flags & RC_NO_LEAF);
2314   bool has_io  = (!is_leaf && !(flags & RC_NO_IO));
2315   if (call_name == NULL) {
2316     assert(!is_leaf, "must supply name for leaf");
2317     call_name = OptoRuntime::stub_name(call_addr);
2318   }
2319   CallNode* call;
2320   if (!is_leaf) {
2321     call = new CallStaticJavaNode(call_type, call_addr, call_name,
2322                                            bci(), adr_type);
2323   } else if (flags & RC_NO_FP) {
2324     call = new CallLeafNoFPNode(call_type, call_addr, call_name, adr_type);
2325   } else {
2326     call = new CallLeafNode(call_type, call_addr, call_name, adr_type);
2327   }
2328 
2329   // The following is similar to set_edges_for_java_call,
2330   // except that the memory effects of the call are restricted to AliasIdxRaw.
2331 
2332   // Slow path call has no side-effects, uses few values
2333   bool wide_in  = !(flags & RC_NARROW_MEM);
2334   bool wide_out = (C->get_alias_index(adr_type) == Compile::AliasIdxBot);
2335 
2336   Node* prev_mem = NULL;
2337   if (wide_in) {
2338     prev_mem = set_predefined_input_for_runtime_call(call);
2339   } else {
2340     assert(!wide_out, "narrow in => narrow out");
2341     Node* narrow_mem = memory(adr_type);
2342     prev_mem = reset_memory();
2343     map()->set_memory(narrow_mem);
2344     set_predefined_input_for_runtime_call(call);
2345   }
2346 
2347   // Hook each parm in order.  Stop looking at the first NULL.
2348   if (parm0 != NULL) { call->init_req(TypeFunc::Parms+0, parm0);
2349   if (parm1 != NULL) { call->init_req(TypeFunc::Parms+1, parm1);
2350   if (parm2 != NULL) { call->init_req(TypeFunc::Parms+2, parm2);
2351   if (parm3 != NULL) { call->init_req(TypeFunc::Parms+3, parm3);
2352   if (parm4 != NULL) { call->init_req(TypeFunc::Parms+4, parm4);
2353   if (parm5 != NULL) { call->init_req(TypeFunc::Parms+5, parm5);
2354   if (parm6 != NULL) { call->init_req(TypeFunc::Parms+6, parm6);
2355   if (parm7 != NULL) { call->init_req(TypeFunc::Parms+7, parm7);
2356     /* close each nested if ===> */  } } } } } } } }
2357   assert(call->in(call->req()-1) != NULL, "must initialize all parms");
2358 
2359   if (!is_leaf) {
2360     // Non-leaves can block and take safepoints:
2361     add_safepoint_edges(call, ((flags & RC_MUST_THROW) != 0));
2362   }
2363   // Non-leaves can throw exceptions:
2364   if (has_io) {
2365     call->set_req(TypeFunc::I_O, i_o());
2366   }
2367 
2368   if (flags & RC_UNCOMMON) {
2369     // Set the count to a tiny probability.  Cf. Estimate_Block_Frequency.
2370     // (An "if" probability corresponds roughly to an unconditional count.
2371     // Sort of.)
2372     call->set_cnt(PROB_UNLIKELY_MAG(4));
2373   }
2374 
2375   Node* c = _gvn.transform(call);
2376   assert(c == call, "cannot disappear");
2377 
2378   if (wide_out) {
2379     // Slow path call has full side-effects.
2380     set_predefined_output_for_runtime_call(call);
2381   } else {
2382     // Slow path call has few side-effects, and/or sets few values.
2383     set_predefined_output_for_runtime_call(call, prev_mem, adr_type);
2384   }
2385 
2386   if (has_io) {
2387     set_i_o(_gvn.transform(new ProjNode(call, TypeFunc::I_O)));
2388   }
2389   return call;
2390 
2391 }
2392 
2393 //------------------------------merge_memory-----------------------------------
2394 // Merge memory from one path into the current memory state.
2395 void GraphKit::merge_memory(Node* new_mem, Node* region, int new_path) {
2396   for (MergeMemStream mms(merged_memory(), new_mem->as_MergeMem()); mms.next_non_empty2(); ) {
2397     Node* old_slice = mms.force_memory();
2398     Node* new_slice = mms.memory2();
2399     if (old_slice != new_slice) {
2400       PhiNode* phi;
2401       if (old_slice->is_Phi() && old_slice->as_Phi()->region() == region) {
2402         if (mms.is_empty()) {
2403           // clone base memory Phi's inputs for this memory slice
2404           assert(old_slice == mms.base_memory(), "sanity");
2405           phi = PhiNode::make(region, NULL, Type::MEMORY, mms.adr_type(C));
2406           _gvn.set_type(phi, Type::MEMORY);
2407           for (uint i = 1; i < phi->req(); i++) {
2408             phi->init_req(i, old_slice->in(i));
2409           }
2410         } else {
2411           phi = old_slice->as_Phi(); // Phi was generated already
2412         }
2413       } else {
2414         phi = PhiNode::make(region, old_slice, Type::MEMORY, mms.adr_type(C));
2415         _gvn.set_type(phi, Type::MEMORY);
2416       }
2417       phi->set_req(new_path, new_slice);
2418       mms.set_memory(phi);
2419     }
2420   }
2421 }
2422 
2423 //------------------------------make_slow_call_ex------------------------------
2424 // Make the exception handler hookups for the slow call
2425 void GraphKit::make_slow_call_ex(Node* call, ciInstanceKlass* ex_klass, bool separate_io_proj, bool deoptimize) {
2426   if (stopped())  return;
2427 
2428   // Make a catch node with just two handlers:  fall-through and catch-all
2429   Node* i_o  = _gvn.transform( new ProjNode(call, TypeFunc::I_O, separate_io_proj) );
2430   Node* catc = _gvn.transform( new CatchNode(control(), i_o, 2) );
2431   Node* norm = _gvn.transform( new CatchProjNode(catc, CatchProjNode::fall_through_index, CatchProjNode::no_handler_bci) );
2432   Node* excp = _gvn.transform( new CatchProjNode(catc, CatchProjNode::catch_all_index,    CatchProjNode::no_handler_bci) );
2433 
2434   { PreserveJVMState pjvms(this);
2435     set_control(excp);
2436     set_i_o(i_o);
2437 
2438     if (excp != top()) {
2439       if (deoptimize) {
2440         // Deoptimize if an exception is caught. Don't construct exception state in this case.
2441         uncommon_trap(Deoptimization::Reason_unhandled,
2442                       Deoptimization::Action_none);
2443       } else {
2444         // Create an exception state also.
2445         // Use an exact type if the caller has specified a specific exception.
2446         const Type* ex_type = TypeOopPtr::make_from_klass_unique(ex_klass)->cast_to_ptr_type(TypePtr::NotNull);
2447         Node*       ex_oop  = new CreateExNode(ex_type, control(), i_o);
2448         add_exception_state(make_exception_state(_gvn.transform(ex_oop)));
2449       }
2450     }
2451   }
2452 
2453   // Get the no-exception control from the CatchNode.
2454   set_control(norm);
2455 }
2456 
2457 static IfNode* gen_subtype_check_compare(Node* ctrl, Node* in1, Node* in2, BoolTest::mask test, float p, PhaseGVN* gvn, BasicType bt) {
2458   Node* cmp = NULL;
2459   switch(bt) {
2460   case T_INT: cmp = new CmpINode(in1, in2); break;
2461   case T_ADDRESS: cmp = new CmpPNode(in1, in2); break;
2462   default: fatal("unexpected comparison type %s", type2name(bt));
2463   }
2464   gvn->transform(cmp);
2465   Node* bol = gvn->transform(new BoolNode(cmp, test));
2466   IfNode* iff = new IfNode(ctrl, bol, p, COUNT_UNKNOWN);
2467   gvn->transform(iff);
2468   if (!bol->is_Con()) gvn->record_for_igvn(iff);
2469   return iff;
2470 }
2471 
2472 
2473 //-------------------------------gen_subtype_check-----------------------------
2474 // Generate a subtyping check.  Takes as input the subtype and supertype.
2475 // Returns 2 values: sets the default control() to the true path and returns
2476 // the false path.  Only reads invariant memory; sets no (visible) memory.
2477 // The PartialSubtypeCheckNode sets the hidden 1-word cache in the encoding
2478 // but that's not exposed to the optimizer.  This call also doesn't take in an
2479 // Object; if you wish to check an Object you need to load the Object's class
2480 // prior to coming here.
2481 Node* Phase::gen_subtype_check(Node* subklass, Node* superklass, Node** ctrl, MergeMemNode* mem, PhaseGVN* gvn) {
2482   Compile* C = gvn->C;
2483 
2484   if ((*ctrl)->is_top()) {
2485     return C->top();
2486   }
2487 
2488   // Fast check for identical types, perhaps identical constants.
2489   // The types can even be identical non-constants, in cases
2490   // involving Array.newInstance, Object.clone, etc.
2491   if (subklass == superklass)
2492     return C->top();             // false path is dead; no test needed.
2493 
2494   if (gvn->type(superklass)->singleton()) {
2495     ciKlass* superk = gvn->type(superklass)->is_klassptr()->klass();
2496     ciKlass* subk   = gvn->type(subklass)->is_klassptr()->klass();
2497 
2498     // In the common case of an exact superklass, try to fold up the
2499     // test before generating code.  You may ask, why not just generate
2500     // the code and then let it fold up?  The answer is that the generated
2501     // code will necessarily include null checks, which do not always
2502     // completely fold away.  If they are also needless, then they turn
2503     // into a performance loss.  Example:
2504     //    Foo[] fa = blah(); Foo x = fa[0]; fa[1] = x;
2505     // Here, the type of 'fa' is often exact, so the store check
2506     // of fa[1]=x will fold up, without testing the nullness of x.
2507     switch (C->static_subtype_check(superk, subk)) {
2508     case Compile::SSC_always_false:
2509       {
2510         Node* always_fail = *ctrl;
2511         *ctrl = gvn->C->top();
2512         return always_fail;
2513       }
2514     case Compile::SSC_always_true:
2515       return C->top();
2516     case Compile::SSC_easy_test:
2517       {
2518         // Just do a direct pointer compare and be done.
2519         IfNode* iff = gen_subtype_check_compare(*ctrl, subklass, superklass, BoolTest::eq, PROB_STATIC_FREQUENT, gvn, T_ADDRESS);
2520         *ctrl = gvn->transform(new IfTrueNode(iff));
2521         return gvn->transform(new IfFalseNode(iff));
2522       }
2523     case Compile::SSC_full_test:
2524       break;
2525     default:
2526       ShouldNotReachHere();
2527     }
2528   }
2529 
2530   // %%% Possible further optimization:  Even if the superklass is not exact,
2531   // if the subklass is the unique subtype of the superklass, the check
2532   // will always succeed.  We could leave a dependency behind to ensure this.
2533 
2534   // First load the super-klass's check-offset
2535   Node *p1 = gvn->transform(new AddPNode(superklass, superklass, gvn->MakeConX(in_bytes(Klass::super_check_offset_offset()))));
2536   Node* m = mem->memory_at(C->get_alias_index(gvn->type(p1)->is_ptr()));
2537   Node *chk_off = gvn->transform(new LoadINode(NULL, m, p1, gvn->type(p1)->is_ptr(), TypeInt::INT, MemNode::unordered));
2538   int cacheoff_con = in_bytes(Klass::secondary_super_cache_offset());
2539   bool might_be_cache = (gvn->find_int_con(chk_off, cacheoff_con) == cacheoff_con);
2540 
2541   // Load from the sub-klass's super-class display list, or a 1-word cache of
2542   // the secondary superclass list, or a failing value with a sentinel offset
2543   // if the super-klass is an interface or exceptionally deep in the Java
2544   // hierarchy and we have to scan the secondary superclass list the hard way.
2545   // Worst-case type is a little odd: NULL is allowed as a result (usually
2546   // klass loads can never produce a NULL).
2547   Node *chk_off_X = chk_off;
2548 #ifdef _LP64
2549   chk_off_X = gvn->transform(new ConvI2LNode(chk_off_X));
2550 #endif
2551   Node *p2 = gvn->transform(new AddPNode(subklass,subklass,chk_off_X));
2552   // For some types like interfaces the following loadKlass is from a 1-word
2553   // cache which is mutable so can't use immutable memory.  Other
2554   // types load from the super-class display table which is immutable.
2555   m = mem->memory_at(C->get_alias_index(gvn->type(p2)->is_ptr()));
2556   Node *kmem = might_be_cache ? m : C->immutable_memory();
2557   Node *nkls = gvn->transform(LoadKlassNode::make(*gvn, NULL, kmem, p2, gvn->type(p2)->is_ptr(), TypeKlassPtr::OBJECT_OR_NULL));
2558 
2559   // Compile speed common case: ARE a subtype and we canNOT fail
2560   if( superklass == nkls )
2561     return C->top();             // false path is dead; no test needed.
2562 
2563   // See if we get an immediate positive hit.  Happens roughly 83% of the
2564   // time.  Test to see if the value loaded just previously from the subklass
2565   // is exactly the superklass.
2566   IfNode *iff1 = gen_subtype_check_compare(*ctrl, superklass, nkls, BoolTest::eq, PROB_LIKELY(0.83f), gvn, T_ADDRESS);
2567   Node *iftrue1 = gvn->transform( new IfTrueNode (iff1));
2568   *ctrl = gvn->transform(new IfFalseNode(iff1));
2569 
2570   // Compile speed common case: Check for being deterministic right now.  If
2571   // chk_off is a constant and not equal to cacheoff then we are NOT a
2572   // subklass.  In this case we need exactly the 1 test above and we can
2573   // return those results immediately.
2574   if (!might_be_cache) {
2575     Node* not_subtype_ctrl = *ctrl;
2576     *ctrl = iftrue1; // We need exactly the 1 test above
2577     return not_subtype_ctrl;
2578   }
2579 
2580   // Gather the various success & failures here
2581   RegionNode *r_ok_subtype = new RegionNode(4);
2582   gvn->record_for_igvn(r_ok_subtype);
2583   RegionNode *r_not_subtype = new RegionNode(3);
2584   gvn->record_for_igvn(r_not_subtype);
2585 
2586   r_ok_subtype->init_req(1, iftrue1);
2587 
2588   // Check for immediate negative hit.  Happens roughly 11% of the time (which
2589   // is roughly 63% of the remaining cases).  Test to see if the loaded
2590   // check-offset points into the subklass display list or the 1-element
2591   // cache.  If it points to the display (and NOT the cache) and the display
2592   // missed then it's not a subtype.
2593   Node *cacheoff = gvn->intcon(cacheoff_con);
2594   IfNode *iff2 = gen_subtype_check_compare(*ctrl, chk_off, cacheoff, BoolTest::ne, PROB_LIKELY(0.63f), gvn, T_INT);
2595   r_not_subtype->init_req(1, gvn->transform(new IfTrueNode (iff2)));
2596   *ctrl = gvn->transform(new IfFalseNode(iff2));
2597 
2598   // Check for self.  Very rare to get here, but it is taken 1/3 the time.
2599   // No performance impact (too rare) but allows sharing of secondary arrays
2600   // which has some footprint reduction.
2601   IfNode *iff3 = gen_subtype_check_compare(*ctrl, subklass, superklass, BoolTest::eq, PROB_LIKELY(0.36f), gvn, T_ADDRESS);
2602   r_ok_subtype->init_req(2, gvn->transform(new IfTrueNode(iff3)));
2603   *ctrl = gvn->transform(new IfFalseNode(iff3));
2604 
2605   // -- Roads not taken here: --
2606   // We could also have chosen to perform the self-check at the beginning
2607   // of this code sequence, as the assembler does.  This would not pay off
2608   // the same way, since the optimizer, unlike the assembler, can perform
2609   // static type analysis to fold away many successful self-checks.
2610   // Non-foldable self checks work better here in second position, because
2611   // the initial primary superclass check subsumes a self-check for most
2612   // types.  An exception would be a secondary type like array-of-interface,
2613   // which does not appear in its own primary supertype display.
2614   // Finally, we could have chosen to move the self-check into the
2615   // PartialSubtypeCheckNode, and from there out-of-line in a platform
2616   // dependent manner.  But it is worthwhile to have the check here,
2617   // where it can be perhaps be optimized.  The cost in code space is
2618   // small (register compare, branch).
2619 
2620   // Now do a linear scan of the secondary super-klass array.  Again, no real
2621   // performance impact (too rare) but it's gotta be done.
2622   // Since the code is rarely used, there is no penalty for moving it
2623   // out of line, and it can only improve I-cache density.
2624   // The decision to inline or out-of-line this final check is platform
2625   // dependent, and is found in the AD file definition of PartialSubtypeCheck.
2626   Node* psc = gvn->transform(
2627     new PartialSubtypeCheckNode(*ctrl, subklass, superklass));
2628 
2629   IfNode *iff4 = gen_subtype_check_compare(*ctrl, psc, gvn->zerocon(T_OBJECT), BoolTest::ne, PROB_FAIR, gvn, T_ADDRESS);
2630   r_not_subtype->init_req(2, gvn->transform(new IfTrueNode (iff4)));
2631   r_ok_subtype ->init_req(3, gvn->transform(new IfFalseNode(iff4)));
2632 
2633   // Return false path; set default control to true path.
2634   *ctrl = gvn->transform(r_ok_subtype);
2635   return gvn->transform(r_not_subtype);
2636 }
2637 
2638 // Profile-driven exact type check:
2639 Node* GraphKit::type_check_receiver(Node* receiver, ciKlass* klass,
2640                                     float prob,
2641                                     Node* *casted_receiver) {
2642   const TypeKlassPtr* tklass = TypeKlassPtr::make(klass);
2643   Node* recv_klass = load_object_klass(receiver);
2644   Node* want_klass = makecon(tklass);
2645   Node* cmp = _gvn.transform( new CmpPNode(recv_klass, want_klass) );
2646   Node* bol = _gvn.transform( new BoolNode(cmp, BoolTest::eq) );
2647   IfNode* iff = create_and_xform_if(control(), bol, prob, COUNT_UNKNOWN);
2648   set_control( _gvn.transform( new IfTrueNode (iff) ));
2649   Node* fail = _gvn.transform( new IfFalseNode(iff) );
2650 
2651   const TypeOopPtr* recv_xtype = tklass->as_instance_type();
2652   assert(recv_xtype->klass_is_exact(), "");
2653 
2654   // Subsume downstream occurrences of receiver with a cast to
2655   // recv_xtype, since now we know what the type will be.
2656   Node* cast = new CheckCastPPNode(control(), receiver, recv_xtype);
2657   (*casted_receiver) = _gvn.transform(cast);
2658   // (User must make the replace_in_map call.)
2659 
2660   return fail;
2661 }
2662 












2663 
2664 //------------------------------seems_never_null-------------------------------
2665 // Use null_seen information if it is available from the profile.
2666 // If we see an unexpected null at a type check we record it and force a
2667 // recompile; the offending check will be recompiled to handle NULLs.
2668 // If we see several offending BCIs, then all checks in the
2669 // method will be recompiled.
2670 bool GraphKit::seems_never_null(Node* obj, ciProfileData* data, bool& speculating) {
2671   speculating = !_gvn.type(obj)->speculative_maybe_null();
2672   Deoptimization::DeoptReason reason = Deoptimization::reason_null_check(speculating);
2673   if (UncommonNullCast               // Cutout for this technique
2674       && obj != null()               // And not the -Xcomp stupid case?
2675       && !too_many_traps(reason)
2676       ) {
2677     if (speculating) {
2678       return true;
2679     }
2680     if (data == NULL)
2681       // Edge case:  no mature data.  Be optimistic here.
2682       return true;
2683     // If the profile has not seen a null, assume it won't happen.
2684     assert(java_bc() == Bytecodes::_checkcast ||
2685            java_bc() == Bytecodes::_instanceof ||
2686            java_bc() == Bytecodes::_aastore, "MDO must collect null_seen bit here");
2687     return !data->as_BitData()->null_seen();
2688   }
2689   speculating = false;
2690   return false;
2691 }
2692 
2693 //------------------------maybe_cast_profiled_receiver-------------------------
2694 // If the profile has seen exactly one type, narrow to exactly that type.
2695 // Subsequent type checks will always fold up.
2696 Node* GraphKit::maybe_cast_profiled_receiver(Node* not_null_obj,
2697                                              ciKlass* require_klass,
2698                                              ciKlass* spec_klass,
2699                                              bool safe_for_replace) {
2700   if (!UseTypeProfile || !TypeProfileCasts) return NULL;
2701 
2702   Deoptimization::DeoptReason reason = Deoptimization::reason_class_check(spec_klass != NULL);
2703 
2704   // Make sure we haven't already deoptimized from this tactic.
2705   if (too_many_traps(reason) || too_many_recompiles(reason))
2706     return NULL;
2707 
2708   // (No, this isn't a call, but it's enough like a virtual call
2709   // to use the same ciMethod accessor to get the profile info...)
2710   // If we have a speculative type use it instead of profiling (which
2711   // may not help us)
2712   ciKlass* exact_kls = spec_klass == NULL ? profile_has_unique_klass() : spec_klass;
2713   if (exact_kls != NULL) {// no cast failures here
2714     if (require_klass == NULL ||
2715         C->static_subtype_check(require_klass, exact_kls) == Compile::SSC_always_true) {
2716       // If we narrow the type to match what the type profile sees or
2717       // the speculative type, we can then remove the rest of the
2718       // cast.
2719       // This is a win, even if the exact_kls is very specific,
2720       // because downstream operations, such as method calls,
2721       // will often benefit from the sharper type.
2722       Node* exact_obj = not_null_obj; // will get updated in place...
2723       Node* slow_ctl  = type_check_receiver(exact_obj, exact_kls, 1.0,
2724                                             &exact_obj);
2725       { PreserveJVMState pjvms(this);
2726         set_control(slow_ctl);
2727         uncommon_trap_exact(reason, Deoptimization::Action_maybe_recompile);
2728       }
2729       if (safe_for_replace) {
2730         replace_in_map(not_null_obj, exact_obj);
2731       }
2732       return exact_obj;
2733     }
2734     // assert(ssc == Compile::SSC_always_true)... except maybe the profile lied to us.
2735   }
2736 
2737   return NULL;
2738 }
2739 
2740 /**
2741  * Cast obj to type and emit guard unless we had too many traps here
2742  * already
2743  *
2744  * @param obj       node being casted
2745  * @param type      type to cast the node to
2746  * @param not_null  true if we know node cannot be null
2747  */
2748 Node* GraphKit::maybe_cast_profiled_obj(Node* obj,
2749                                         ciKlass* type,
2750                                         bool not_null) {
2751   if (stopped()) {
2752     return obj;
2753   }
2754 
2755   // type == NULL if profiling tells us this object is always null
2756   if (type != NULL) {
2757     Deoptimization::DeoptReason class_reason = Deoptimization::Reason_speculate_class_check;
2758     Deoptimization::DeoptReason null_reason = Deoptimization::Reason_speculate_null_check;
2759 
2760     if (!too_many_traps(null_reason) && !too_many_recompiles(null_reason) &&
2761         !too_many_traps(class_reason) &&
2762         !too_many_recompiles(class_reason)) {
2763       Node* not_null_obj = NULL;
2764       // not_null is true if we know the object is not null and
2765       // there's no need for a null check
2766       if (!not_null) {
2767         Node* null_ctl = top();
2768         not_null_obj = null_check_oop(obj, &null_ctl, true, true, true);
2769         assert(null_ctl->is_top(), "no null control here");
2770       } else {
2771         not_null_obj = obj;
2772       }
2773 
2774       Node* exact_obj = not_null_obj;
2775       ciKlass* exact_kls = type;
2776       Node* slow_ctl  = type_check_receiver(exact_obj, exact_kls, 1.0,
2777                                             &exact_obj);
2778       {
2779         PreserveJVMState pjvms(this);
2780         set_control(slow_ctl);
2781         uncommon_trap_exact(class_reason, Deoptimization::Action_maybe_recompile);
2782       }
2783       replace_in_map(not_null_obj, exact_obj);
2784       obj = exact_obj;
2785     }
2786   } else {
2787     if (!too_many_traps(Deoptimization::Reason_null_assert) &&
2788         !too_many_recompiles(Deoptimization::Reason_null_assert)) {
2789       Node* exact_obj = null_assert(obj);
2790       replace_in_map(obj, exact_obj);
2791       obj = exact_obj;
2792     }
2793   }
2794   return obj;
2795 }
2796 
2797 //-------------------------------gen_instanceof--------------------------------
2798 // Generate an instance-of idiom.  Used by both the instance-of bytecode
2799 // and the reflective instance-of call.
2800 Node* GraphKit::gen_instanceof(Node* obj, Node* superklass, bool safe_for_replace) {
2801   kill_dead_locals();           // Benefit all the uncommon traps
2802   assert( !stopped(), "dead parse path should be checked in callers" );
2803   assert(!TypePtr::NULL_PTR->higher_equal(_gvn.type(superklass)->is_klassptr()),
2804          "must check for not-null not-dead klass in callers");
2805 
2806   // Make the merge point
2807   enum { _obj_path = 1, _fail_path, _null_path, PATH_LIMIT };
2808   RegionNode* region = new RegionNode(PATH_LIMIT);
2809   Node*       phi    = new PhiNode(region, TypeInt::BOOL);
2810   C->set_has_split_ifs(true); // Has chance for split-if optimization
2811 
2812   ciProfileData* data = NULL;
2813   if (java_bc() == Bytecodes::_instanceof) {  // Only for the bytecode
2814     data = method()->method_data()->bci_to_data(bci());
2815   }
2816   bool speculative_not_null = false;
2817   bool never_see_null = (ProfileDynamicTypes  // aggressive use of profile
2818                          && seems_never_null(obj, data, speculative_not_null));
2819 
2820   // Null check; get casted pointer; set region slot 3
2821   Node* null_ctl = top();
2822   Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null, safe_for_replace, speculative_not_null);
2823 
2824   // If not_null_obj is dead, only null-path is taken
2825   if (stopped()) {              // Doing instance-of on a NULL?
2826     set_control(null_ctl);
2827     return intcon(0);
2828   }
2829   region->init_req(_null_path, null_ctl);
2830   phi   ->init_req(_null_path, intcon(0)); // Set null path value
2831   if (null_ctl == top()) {
2832     // Do this eagerly, so that pattern matches like is_diamond_phi
2833     // will work even during parsing.
2834     assert(_null_path == PATH_LIMIT-1, "delete last");
2835     region->del_req(_null_path);
2836     phi   ->del_req(_null_path);
2837   }
2838 
2839   // Do we know the type check always succeed?
2840   bool known_statically = false;
2841   if (_gvn.type(superklass)->singleton()) {
2842     ciKlass* superk = _gvn.type(superklass)->is_klassptr()->klass();
2843     ciKlass* subk = _gvn.type(obj)->is_oopptr()->klass();
2844     if (subk != NULL && subk->is_loaded()) {
2845       int static_res = C->static_subtype_check(superk, subk);
2846       known_statically = (static_res == Compile::SSC_always_true || static_res == Compile::SSC_always_false);
2847     }
2848   }
2849 
2850   if (known_statically && UseTypeSpeculation) {
2851     // If we know the type check always succeeds then we don't use the
2852     // profiling data at this bytecode. Don't lose it, feed it to the
2853     // type system as a speculative type.
2854     not_null_obj = record_profiled_receiver_for_speculation(not_null_obj);
2855   } else {
2856     const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
2857     // We may not have profiling here or it may not help us. If we
2858     // have a speculative type use it to perform an exact cast.
2859     ciKlass* spec_obj_type = obj_type->speculative_type();
2860     if (spec_obj_type != NULL || (ProfileDynamicTypes && data != NULL)) {
2861       Node* cast_obj = maybe_cast_profiled_receiver(not_null_obj, NULL, spec_obj_type, safe_for_replace);
2862       if (stopped()) {            // Profile disagrees with this path.
2863         set_control(null_ctl);    // Null is the only remaining possibility.
2864         return intcon(0);
2865       }
2866       if (cast_obj != NULL) {
2867         not_null_obj = cast_obj;
2868       }
2869     }
2870   }
2871 
2872   // Load the object's klass
2873   Node* obj_klass = load_object_klass(not_null_obj);
2874 
2875   // Generate the subtype check
2876   Node* not_subtype_ctrl = gen_subtype_check(obj_klass, superklass);
2877 
2878   // Plug in the success path to the general merge in slot 1.
2879   region->init_req(_obj_path, control());
2880   phi   ->init_req(_obj_path, intcon(1));
2881 
2882   // Plug in the failing path to the general merge in slot 2.
2883   region->init_req(_fail_path, not_subtype_ctrl);
2884   phi   ->init_req(_fail_path, intcon(0));
2885 
2886   // Return final merged results
2887   set_control( _gvn.transform(region) );
2888   record_for_igvn(region);
2889   return _gvn.transform(phi);
2890 }
2891 
2892 //-------------------------------gen_checkcast---------------------------------
2893 // Generate a checkcast idiom.  Used by both the checkcast bytecode and the
2894 // array store bytecode.  Stack must be as-if BEFORE doing the bytecode so the
2895 // uncommon-trap paths work.  Adjust stack after this call.
2896 // If failure_control is supplied and not null, it is filled in with
2897 // the control edge for the cast failure.  Otherwise, an appropriate
2898 // uncommon trap or exception is thrown.
2899 Node* GraphKit::gen_checkcast(Node *obj, Node* superklass,
2900                               Node* *failure_control) {
2901   kill_dead_locals();           // Benefit all the uncommon traps
2902   const TypeKlassPtr *tk = _gvn.type(superklass)->is_klassptr();
2903   const Type *toop = TypeOopPtr::make_from_klass(tk->klass());
2904 
2905   // Fast cutout:  Check the case that the cast is vacuously true.
2906   // This detects the common cases where the test will short-circuit
2907   // away completely.  We do this before we perform the null check,
2908   // because if the test is going to turn into zero code, we don't
2909   // want a residual null check left around.  (Causes a slowdown,
2910   // for example, in some objArray manipulations, such as a[i]=a[j].)
2911   if (tk->singleton()) {
2912     const TypeOopPtr* objtp = _gvn.type(obj)->isa_oopptr();
2913     if (objtp != NULL && objtp->klass() != NULL) {
2914       switch (C->static_subtype_check(tk->klass(), objtp->klass())) {
2915       case Compile::SSC_always_true:
2916         // If we know the type check always succeed then we don't use
2917         // the profiling data at this bytecode. Don't lose it, feed it
2918         // to the type system as a speculative type.
2919         return record_profiled_receiver_for_speculation(obj);
2920       case Compile::SSC_always_false:
2921         // It needs a null check because a null will *pass* the cast check.
2922         // A non-null value will always produce an exception.
2923         return null_assert(obj);
2924       }
2925     }
2926   }
2927 
2928   ciProfileData* data = NULL;
2929   bool safe_for_replace = false;
2930   if (failure_control == NULL) {        // use MDO in regular case only
2931     assert(java_bc() == Bytecodes::_aastore ||
2932            java_bc() == Bytecodes::_checkcast,
2933            "interpreter profiles type checks only for these BCs");
2934     data = method()->method_data()->bci_to_data(bci());
2935     safe_for_replace = true;
2936   }
2937 
2938   // Make the merge point
2939   enum { _obj_path = 1, _null_path, PATH_LIMIT };
2940   RegionNode* region = new RegionNode(PATH_LIMIT);
2941   Node*       phi    = new PhiNode(region, toop);
2942   C->set_has_split_ifs(true); // Has chance for split-if optimization
2943 
2944   // Use null-cast information if it is available
2945   bool speculative_not_null = false;
2946   bool never_see_null = ((failure_control == NULL)  // regular case only
2947                          && seems_never_null(obj, data, speculative_not_null));
2948 
2949   // Null check; get casted pointer; set region slot 3
2950   Node* null_ctl = top();
2951   Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null, safe_for_replace, speculative_not_null);
2952 
2953   // If not_null_obj is dead, only null-path is taken
2954   if (stopped()) {              // Doing instance-of on a NULL?
2955     set_control(null_ctl);
2956     return null();
2957   }
2958   region->init_req(_null_path, null_ctl);
2959   phi   ->init_req(_null_path, null());  // Set null path value
2960   if (null_ctl == top()) {
2961     // Do this eagerly, so that pattern matches like is_diamond_phi
2962     // will work even during parsing.
2963     assert(_null_path == PATH_LIMIT-1, "delete last");
2964     region->del_req(_null_path);
2965     phi   ->del_req(_null_path);
2966   }
2967 
2968   Node* cast_obj = NULL;
2969   if (tk->klass_is_exact()) {
2970     // The following optimization tries to statically cast the speculative type of the object
2971     // (for example obtained during profiling) to the type of the superklass and then do a
2972     // dynamic check that the type of the object is what we expect. To work correctly
2973     // for checkcast and aastore the type of superklass should be exact.
2974     const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
2975     // We may not have profiling here or it may not help us. If we have
2976     // a speculative type use it to perform an exact cast.
2977     ciKlass* spec_obj_type = obj_type->speculative_type();
2978     if (spec_obj_type != NULL || data != NULL) {
2979       cast_obj = maybe_cast_profiled_receiver(not_null_obj, tk->klass(), spec_obj_type, safe_for_replace);
2980       if (cast_obj != NULL) {
2981         if (failure_control != NULL) // failure is now impossible
2982           (*failure_control) = top();
2983         // adjust the type of the phi to the exact klass:
2984         phi->raise_bottom_type(_gvn.type(cast_obj)->meet_speculative(TypePtr::NULL_PTR));
2985       }
2986     }
2987   }
2988 
2989   if (cast_obj == NULL) {
2990     // Load the object's klass
2991     Node* obj_klass = load_object_klass(not_null_obj);
2992 
2993     // Generate the subtype check
2994     Node* not_subtype_ctrl = gen_subtype_check( obj_klass, superklass );
2995 
2996     // Plug in success path into the merge
2997     cast_obj = _gvn.transform(new CheckCastPPNode(control(), not_null_obj, toop));
2998     // Failure path ends in uncommon trap (or may be dead - failure impossible)
2999     if (failure_control == NULL) {
3000       if (not_subtype_ctrl != top()) { // If failure is possible
3001         PreserveJVMState pjvms(this);
3002         set_control(not_subtype_ctrl);
3003         builtin_throw(Deoptimization::Reason_class_check, obj_klass);
3004       }
3005     } else {
3006       (*failure_control) = not_subtype_ctrl;
3007     }
3008   }
3009 
3010   region->init_req(_obj_path, control());
3011   phi   ->init_req(_obj_path, cast_obj);
3012 
3013   // A merge of NULL or Casted-NotNull obj
3014   Node* res = _gvn.transform(phi);
3015 
3016   // Note I do NOT always 'replace_in_map(obj,result)' here.
3017   //  if( tk->klass()->can_be_primary_super()  )
3018     // This means that if I successfully store an Object into an array-of-String
3019     // I 'forget' that the Object is really now known to be a String.  I have to
3020     // do this because we don't have true union types for interfaces - if I store
3021     // a Baz into an array-of-Interface and then tell the optimizer it's an
3022     // Interface, I forget that it's also a Baz and cannot do Baz-like field
3023     // references to it.  FIX THIS WHEN UNION TYPES APPEAR!
3024   //  replace_in_map( obj, res );
3025 
3026   // Return final merged results
3027   set_control( _gvn.transform(region) );
3028   record_for_igvn(region);
3029   return res;
3030 }
3031 
3032 //------------------------------next_monitor-----------------------------------
3033 // What number should be given to the next monitor?
3034 int GraphKit::next_monitor() {
3035   int current = jvms()->monitor_depth()* C->sync_stack_slots();
3036   int next = current + C->sync_stack_slots();
3037   // Keep the toplevel high water mark current:
3038   if (C->fixed_slots() < next)  C->set_fixed_slots(next);
3039   return current;
3040 }
3041 
3042 //------------------------------insert_mem_bar---------------------------------
3043 // Memory barrier to avoid floating things around
3044 // The membar serves as a pinch point between both control and all memory slices.
3045 Node* GraphKit::insert_mem_bar(int opcode, Node* precedent) {
3046   MemBarNode* mb = MemBarNode::make(C, opcode, Compile::AliasIdxBot, precedent);
3047   mb->init_req(TypeFunc::Control, control());
3048   mb->init_req(TypeFunc::Memory,  reset_memory());
3049   Node* membar = _gvn.transform(mb);
3050   set_control(_gvn.transform(new ProjNode(membar, TypeFunc::Control)));
3051   set_all_memory_call(membar);
3052   return membar;
3053 }
3054 
3055 //-------------------------insert_mem_bar_volatile----------------------------
3056 // Memory barrier to avoid floating things around
3057 // The membar serves as a pinch point between both control and memory(alias_idx).
3058 // If you want to make a pinch point on all memory slices, do not use this
3059 // function (even with AliasIdxBot); use insert_mem_bar() instead.
3060 Node* GraphKit::insert_mem_bar_volatile(int opcode, int alias_idx, Node* precedent) {
3061   // When Parse::do_put_xxx updates a volatile field, it appends a series
3062   // of MemBarVolatile nodes, one for *each* volatile field alias category.
3063   // The first membar is on the same memory slice as the field store opcode.
3064   // This forces the membar to follow the store.  (Bug 6500685 broke this.)
3065   // All the other membars (for other volatile slices, including AliasIdxBot,
3066   // which stands for all unknown volatile slices) are control-dependent
3067   // on the first membar.  This prevents later volatile loads or stores
3068   // from sliding up past the just-emitted store.
3069 
3070   MemBarNode* mb = MemBarNode::make(C, opcode, alias_idx, precedent);
3071   mb->set_req(TypeFunc::Control,control());
3072   if (alias_idx == Compile::AliasIdxBot) {
3073     mb->set_req(TypeFunc::Memory, merged_memory()->base_memory());
3074   } else {
3075     assert(!(opcode == Op_Initialize && alias_idx != Compile::AliasIdxRaw), "fix caller");
3076     mb->set_req(TypeFunc::Memory, memory(alias_idx));
3077   }
3078   Node* membar = _gvn.transform(mb);
3079   set_control(_gvn.transform(new ProjNode(membar, TypeFunc::Control)));
3080   if (alias_idx == Compile::AliasIdxBot) {
3081     merged_memory()->set_base_memory(_gvn.transform(new ProjNode(membar, TypeFunc::Memory)));
3082   } else {
3083     set_memory(_gvn.transform(new ProjNode(membar, TypeFunc::Memory)),alias_idx);
3084   }
3085   return membar;
3086 }
3087 
3088 //------------------------------shared_lock------------------------------------
3089 // Emit locking code.
3090 FastLockNode* GraphKit::shared_lock(Node* obj) {
3091   // bci is either a monitorenter bc or InvocationEntryBci
3092   // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
3093   assert(SynchronizationEntryBCI == InvocationEntryBci, "");
3094 
3095   if( !GenerateSynchronizationCode )
3096     return NULL;                // Not locking things?
3097   if (stopped())                // Dead monitor?
3098     return NULL;
3099 
3100   assert(dead_locals_are_killed(), "should kill locals before sync. point");
3101 
3102   // Box the stack location
3103   Node* box = _gvn.transform(new BoxLockNode(next_monitor()));
3104   Node* mem = reset_memory();
3105 
3106   FastLockNode * flock = _gvn.transform(new FastLockNode(0, obj, box) )->as_FastLock();
3107   if (UseBiasedLocking && PrintPreciseBiasedLockingStatistics) {
3108     // Create the counters for this fast lock.
3109     flock->create_lock_counter(sync_jvms()); // sync_jvms used to get current bci
3110   }
3111 
3112   // Create the rtm counters for this fast lock if needed.
3113   flock->create_rtm_lock_counter(sync_jvms()); // sync_jvms used to get current bci
3114 
3115   // Add monitor to debug info for the slow path.  If we block inside the
3116   // slow path and de-opt, we need the monitor hanging around
3117   map()->push_monitor( flock );
3118 
3119   const TypeFunc *tf = LockNode::lock_type();
3120   LockNode *lock = new LockNode(C, tf);
3121 
3122   lock->init_req( TypeFunc::Control, control() );
3123   lock->init_req( TypeFunc::Memory , mem );
3124   lock->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
3125   lock->init_req( TypeFunc::FramePtr, frameptr() );
3126   lock->init_req( TypeFunc::ReturnAdr, top() );
3127 
3128   lock->init_req(TypeFunc::Parms + 0, obj);
3129   lock->init_req(TypeFunc::Parms + 1, box);
3130   lock->init_req(TypeFunc::Parms + 2, flock);
3131   add_safepoint_edges(lock);
3132 
3133   lock = _gvn.transform( lock )->as_Lock();
3134 
3135   // lock has no side-effects, sets few values
3136   set_predefined_output_for_runtime_call(lock, mem, TypeRawPtr::BOTTOM);
3137 
3138   insert_mem_bar(Op_MemBarAcquireLock);
3139 
3140   // Add this to the worklist so that the lock can be eliminated
3141   record_for_igvn(lock);
3142 
3143 #ifndef PRODUCT
3144   if (PrintLockStatistics) {
3145     // Update the counter for this lock.  Don't bother using an atomic
3146     // operation since we don't require absolute accuracy.
3147     lock->create_lock_counter(map()->jvms());
3148     increment_counter(lock->counter()->addr());
3149   }
3150 #endif
3151 
3152   return flock;
3153 }
3154 
3155 
3156 //------------------------------shared_unlock----------------------------------
3157 // Emit unlocking code.
3158 void GraphKit::shared_unlock(Node* box, Node* obj) {
3159   // bci is either a monitorenter bc or InvocationEntryBci
3160   // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
3161   assert(SynchronizationEntryBCI == InvocationEntryBci, "");
3162 
3163   if( !GenerateSynchronizationCode )
3164     return;
3165   if (stopped()) {               // Dead monitor?
3166     map()->pop_monitor();        // Kill monitor from debug info
3167     return;
3168   }
3169 
3170   // Memory barrier to avoid floating things down past the locked region
3171   insert_mem_bar(Op_MemBarReleaseLock);
3172 
3173   const TypeFunc *tf = OptoRuntime::complete_monitor_exit_Type();
3174   UnlockNode *unlock = new UnlockNode(C, tf);
3175 #ifdef ASSERT
3176   unlock->set_dbg_jvms(sync_jvms());
3177 #endif
3178   uint raw_idx = Compile::AliasIdxRaw;
3179   unlock->init_req( TypeFunc::Control, control() );
3180   unlock->init_req( TypeFunc::Memory , memory(raw_idx) );
3181   unlock->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
3182   unlock->init_req( TypeFunc::FramePtr, frameptr() );
3183   unlock->init_req( TypeFunc::ReturnAdr, top() );
3184 
3185   unlock->init_req(TypeFunc::Parms + 0, obj);
3186   unlock->init_req(TypeFunc::Parms + 1, box);
3187   unlock = _gvn.transform(unlock)->as_Unlock();
3188 
3189   Node* mem = reset_memory();
3190 
3191   // unlock has no side-effects, sets few values
3192   set_predefined_output_for_runtime_call(unlock, mem, TypeRawPtr::BOTTOM);
3193 
3194   // Kill monitor from debug info
3195   map()->pop_monitor( );
3196 }
3197 
3198 //-------------------------------get_layout_helper-----------------------------
3199 // If the given klass is a constant or known to be an array,
3200 // fetch the constant layout helper value into constant_value
3201 // and return (Node*)NULL.  Otherwise, load the non-constant
3202 // layout helper value, and return the node which represents it.
3203 // This two-faced routine is useful because allocation sites
3204 // almost always feature constant types.
3205 Node* GraphKit::get_layout_helper(Node* klass_node, jint& constant_value) {
3206   const TypeKlassPtr* inst_klass = _gvn.type(klass_node)->isa_klassptr();
3207   if (!StressReflectiveCode && inst_klass != NULL) {
3208     ciKlass* klass = inst_klass->klass();
3209     bool    xklass = inst_klass->klass_is_exact();
3210     if (xklass || klass->is_array_klass()) {
3211       jint lhelper = klass->layout_helper();
3212       if (lhelper != Klass::_lh_neutral_value) {
3213         constant_value = lhelper;
3214         return (Node*) NULL;
3215       }
3216     }
3217   }
3218   constant_value = Klass::_lh_neutral_value;  // put in a known value
3219   Node* lhp = basic_plus_adr(klass_node, klass_node, in_bytes(Klass::layout_helper_offset()));
3220   return make_load(NULL, lhp, TypeInt::INT, T_INT, MemNode::unordered);
3221 }
3222 
3223 // We just put in an allocate/initialize with a big raw-memory effect.
3224 // Hook selected additional alias categories on the initialization.
3225 static void hook_memory_on_init(GraphKit& kit, int alias_idx,
3226                                 MergeMemNode* init_in_merge,
3227                                 Node* init_out_raw) {
3228   DEBUG_ONLY(Node* init_in_raw = init_in_merge->base_memory());
3229   assert(init_in_merge->memory_at(alias_idx) == init_in_raw, "");
3230 
3231   Node* prevmem = kit.memory(alias_idx);
3232   init_in_merge->set_memory_at(alias_idx, prevmem);
3233   kit.set_memory(init_out_raw, alias_idx);
3234 }
3235 
3236 //---------------------------set_output_for_allocation-------------------------
3237 Node* GraphKit::set_output_for_allocation(AllocateNode* alloc,
3238                                           const TypeOopPtr* oop_type,
3239                                           bool deoptimize_on_exception) {
3240   int rawidx = Compile::AliasIdxRaw;
3241   alloc->set_req( TypeFunc::FramePtr, frameptr() );
3242   add_safepoint_edges(alloc);
3243   Node* allocx = _gvn.transform(alloc);
3244   set_control( _gvn.transform(new ProjNode(allocx, TypeFunc::Control) ) );
3245   // create memory projection for i_o
3246   set_memory ( _gvn.transform( new ProjNode(allocx, TypeFunc::Memory, true) ), rawidx );
3247   make_slow_call_ex(allocx, env()->Throwable_klass(), true, deoptimize_on_exception);
3248 
3249   // create a memory projection as for the normal control path
3250   Node* malloc = _gvn.transform(new ProjNode(allocx, TypeFunc::Memory));
3251   set_memory(malloc, rawidx);
3252 
3253   // a normal slow-call doesn't change i_o, but an allocation does
3254   // we create a separate i_o projection for the normal control path
3255   set_i_o(_gvn.transform( new ProjNode(allocx, TypeFunc::I_O, false) ) );
3256   Node* rawoop = _gvn.transform( new ProjNode(allocx, TypeFunc::Parms) );
3257 
3258   // put in an initialization barrier
3259   InitializeNode* init = insert_mem_bar_volatile(Op_Initialize, rawidx,
3260                                                  rawoop)->as_Initialize();
3261   assert(alloc->initialization() == init,  "2-way macro link must work");
3262   assert(init ->allocation()     == alloc, "2-way macro link must work");
3263   {
3264     // Extract memory strands which may participate in the new object's
3265     // initialization, and source them from the new InitializeNode.
3266     // This will allow us to observe initializations when they occur,
3267     // and link them properly (as a group) to the InitializeNode.
3268     assert(init->in(InitializeNode::Memory) == malloc, "");
3269     MergeMemNode* minit_in = MergeMemNode::make(malloc);
3270     init->set_req(InitializeNode::Memory, minit_in);
3271     record_for_igvn(minit_in); // fold it up later, if possible
3272     Node* minit_out = memory(rawidx);
3273     assert(minit_out->is_Proj() && minit_out->in(0) == init, "");
3274     if (oop_type->isa_aryptr()) {
3275       const TypePtr* telemref = oop_type->add_offset(Type::OffsetBot);
3276       int            elemidx  = C->get_alias_index(telemref);
3277       hook_memory_on_init(*this, elemidx, minit_in, minit_out);
3278     } else if (oop_type->isa_instptr() || oop_type->isa_valuetypeptr()) {
3279       ciInstanceKlass* ik = oop_type->klass()->as_instance_klass();
3280       for (int i = 0, len = ik->nof_nonstatic_fields(); i < len; i++) {
3281         ciField* field = ik->nonstatic_field_at(i);
3282         if (field->offset() >= TrackedInitializationLimit * HeapWordSize)
3283           continue;  // do not bother to track really large numbers of fields
3284         // Find (or create) the alias category for this field:
3285         int fieldidx = C->alias_type(field)->index();
3286         hook_memory_on_init(*this, fieldidx, minit_in, minit_out);
3287       }
3288     }
3289   }
3290 
3291   // Cast raw oop to the real thing...
3292   Node* javaoop = new CheckCastPPNode(control(), rawoop, oop_type);
3293   javaoop = _gvn.transform(javaoop);
3294   C->set_recent_alloc(control(), javaoop);
3295   assert(just_allocated_object(control()) == javaoop, "just allocated");
3296 
3297 #ifdef ASSERT
3298   { // Verify that the AllocateNode::Ideal_allocation recognizers work:
3299     assert(AllocateNode::Ideal_allocation(rawoop, &_gvn) == alloc,
3300            "Ideal_allocation works");
3301     assert(AllocateNode::Ideal_allocation(javaoop, &_gvn) == alloc,
3302            "Ideal_allocation works");
3303     if (alloc->is_AllocateArray()) {
3304       assert(AllocateArrayNode::Ideal_array_allocation(rawoop, &_gvn) == alloc->as_AllocateArray(),
3305              "Ideal_allocation works");
3306       assert(AllocateArrayNode::Ideal_array_allocation(javaoop, &_gvn) == alloc->as_AllocateArray(),
3307              "Ideal_allocation works");
3308     } else {
3309       assert(alloc->in(AllocateNode::ALength)->is_top(), "no length, please");
3310     }
3311   }
3312 #endif //ASSERT
3313 
3314   return javaoop;
3315 }
3316 
3317 //---------------------------new_instance--------------------------------------
3318 // This routine takes a klass_node which may be constant (for a static type)
3319 // or may be non-constant (for reflective code).  It will work equally well
3320 // for either, and the graph will fold nicely if the optimizer later reduces
3321 // the type to a constant.
3322 // The optional arguments are for specialized use by intrinsics:
3323 //  - If 'extra_slow_test' if not null is an extra condition for the slow-path.
3324 //  - If 'return_size_val', report the the total object size to the caller.
3325 //  - deoptimize_on_exception controls how Java exceptions are handled (rethrow vs deoptimize)
3326 Node* GraphKit::new_instance(Node* klass_node,
3327                              Node* extra_slow_test,
3328                              Node* *return_size_val,
3329                              bool deoptimize_on_exception) {
3330   // Compute size in doublewords
3331   // The size is always an integral number of doublewords, represented
3332   // as a positive bytewise size stored in the klass's layout_helper.
3333   // The layout_helper also encodes (in a low bit) the need for a slow path.
3334   jint  layout_con = Klass::_lh_neutral_value;
3335   Node* layout_val = get_layout_helper(klass_node, layout_con);
3336   int   layout_is_con = (layout_val == NULL);
3337 
3338   if (extra_slow_test == NULL)  extra_slow_test = intcon(0);
3339   // Generate the initial go-slow test.  It's either ALWAYS (return a
3340   // Node for 1) or NEVER (return a NULL) or perhaps (in the reflective
3341   // case) a computed value derived from the layout_helper.
3342   Node* initial_slow_test = NULL;
3343   if (layout_is_con) {
3344     assert(!StressReflectiveCode, "stress mode does not use these paths");
3345     bool must_go_slow = Klass::layout_helper_needs_slow_path(layout_con);
3346     initial_slow_test = must_go_slow ? intcon(1) : extra_slow_test;
3347   } else {   // reflective case
3348     // This reflective path is used by Unsafe.allocateInstance.
3349     // (It may be stress-tested by specifying StressReflectiveCode.)
3350     // Basically, we want to get into the VM is there's an illegal argument.
3351     Node* bit = intcon(Klass::_lh_instance_slow_path_bit);
3352     initial_slow_test = _gvn.transform( new AndINode(layout_val, bit) );
3353     if (extra_slow_test != intcon(0)) {
3354       initial_slow_test = _gvn.transform( new OrINode(initial_slow_test, extra_slow_test) );
3355     }
3356     // (Macro-expander will further convert this to a Bool, if necessary.)
3357   }
3358 
3359   // Find the size in bytes.  This is easy; it's the layout_helper.
3360   // The size value must be valid even if the slow path is taken.
3361   Node* size = NULL;
3362   if (layout_is_con) {
3363     size = MakeConX(Klass::layout_helper_size_in_bytes(layout_con));
3364   } else {   // reflective case
3365     // This reflective path is used by clone and Unsafe.allocateInstance.
3366     size = ConvI2X(layout_val);
3367 
3368     // Clear the low bits to extract layout_helper_size_in_bytes:
3369     assert((int)Klass::_lh_instance_slow_path_bit < BytesPerLong, "clear bit");
3370     Node* mask = MakeConX(~ (intptr_t)right_n_bits(LogBytesPerLong));
3371     size = _gvn.transform( new AndXNode(size, mask) );
3372   }
3373   if (return_size_val != NULL) {
3374     (*return_size_val) = size;
3375   }
3376 
3377   // This is a precise notnull oop of the klass.
3378   // (Actually, it need not be precise if this is a reflective allocation.)
3379   // It's what we cast the result to.
3380   const TypeKlassPtr* tklass = _gvn.type(klass_node)->isa_klassptr();
3381   if (!tklass)  tklass = TypeKlassPtr::OBJECT;
3382   const TypeOopPtr* oop_type = tklass->as_instance_type();
3383 
3384   // Now generate allocation code
3385 
3386   // The entire memory state is needed for slow path of the allocation
3387   // since GC and deoptimization can happen.
3388   Node *mem = reset_memory();
3389   set_all_memory(mem); // Create new memory state
3390 
3391   AllocateNode* alloc = new AllocateNode(C, AllocateNode::alloc_type(Type::TOP),
3392                                          control(), mem, i_o(),
3393                                          size, klass_node,
3394                                          initial_slow_test);
3395 
3396   return set_output_for_allocation(alloc, oop_type, deoptimize_on_exception);
3397 }
3398 
3399 //-------------------------------new_array-------------------------------------
3400 // helper for newarray, anewarray and vnewarray
3401 // The 'length' parameter is (obviously) the length of the array.
3402 // See comments on new_instance for the meaning of the other arguments.
3403 Node* GraphKit::new_array(Node* klass_node,     // array klass (maybe variable)
3404                           Node* length,         // number of array elements
3405                           int   nargs,          // number of arguments to push back for uncommon trap
3406                           Node* *return_size_val,
3407                           bool deoptimize_on_exception) {
3408   jint  layout_con = Klass::_lh_neutral_value;
3409   Node* layout_val = get_layout_helper(klass_node, layout_con);
3410   int   layout_is_con = (layout_val == NULL);
3411 
3412   if (!layout_is_con && !StressReflectiveCode &&
3413       !too_many_traps(Deoptimization::Reason_class_check)) {
3414     // This is a reflective array creation site.
3415     // Optimistically assume that it is a subtype of Object[],
3416     // so that we can fold up all the address arithmetic.
3417     layout_con = Klass::array_layout_helper(T_OBJECT);
3418     Node* cmp_lh = _gvn.transform( new CmpINode(layout_val, intcon(layout_con)) );
3419     Node* bol_lh = _gvn.transform( new BoolNode(cmp_lh, BoolTest::eq) );
3420     { BuildCutout unless(this, bol_lh, PROB_MAX);
3421       inc_sp(nargs);
3422       uncommon_trap(Deoptimization::Reason_class_check,
3423                     Deoptimization::Action_maybe_recompile);
3424     }
3425     layout_val = NULL;
3426     layout_is_con = true;
3427   }
3428 
3429   // Generate the initial go-slow test.  Make sure we do not overflow
3430   // if length is huge (near 2Gig) or negative!  We do not need
3431   // exact double-words here, just a close approximation of needed
3432   // double-words.  We can't add any offset or rounding bits, lest we
3433   // take a size -1 of bytes and make it positive.  Use an unsigned
3434   // compare, so negative sizes look hugely positive.
3435   int fast_size_limit = FastAllocateSizeLimit;
3436   if (layout_is_con) {
3437     assert(!StressReflectiveCode, "stress mode does not use these paths");
3438     // Increase the size limit if we have exact knowledge of array type.
3439     int log2_esize = Klass::layout_helper_log2_element_size(layout_con);
3440     fast_size_limit <<= (LogBytesPerLong - log2_esize);
3441   }
3442 
3443   Node* initial_slow_cmp  = _gvn.transform( new CmpUNode( length, intcon( fast_size_limit ) ) );
3444   Node* initial_slow_test = _gvn.transform( new BoolNode( initial_slow_cmp, BoolTest::gt ) );
3445 
3446   // --- Size Computation ---
3447   // array_size = round_to_heap(array_header + (length << elem_shift));
3448   // where round_to_heap(x) == round_to(x, MinObjAlignmentInBytes)
3449   // and round_to(x, y) == ((x + y-1) & ~(y-1))
3450   // The rounding mask is strength-reduced, if possible.
3451   int round_mask = MinObjAlignmentInBytes - 1;
3452   Node* header_size = NULL;
3453   int   header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
3454   // (T_BYTE has the weakest alignment and size restrictions...)
3455   if (layout_is_con) {
3456     int       hsize  = Klass::layout_helper_header_size(layout_con);
3457     int       eshift = Klass::layout_helper_log2_element_size(layout_con);
3458     BasicType etype  = Klass::layout_helper_element_type(layout_con);
3459     bool is_value_array = Klass::layout_helper_is_valueArray(layout_con);
3460     if ((round_mask & ~right_n_bits(eshift)) == 0)
3461       round_mask = 0;  // strength-reduce it if it goes away completely
3462     assert(is_value_array || (hsize & right_n_bits(eshift)) == 0, "hsize is pre-rounded");
3463     assert(header_size_min <= hsize, "generic minimum is smallest");
3464     header_size_min = hsize;
3465     header_size = intcon(hsize + round_mask);
3466   } else {
3467     Node* hss   = intcon(Klass::_lh_header_size_shift);
3468     Node* hsm   = intcon(Klass::_lh_header_size_mask);
3469     Node* hsize = _gvn.transform( new URShiftINode(layout_val, hss) );
3470     hsize       = _gvn.transform( new AndINode(hsize, hsm) );
3471     Node* mask  = intcon(round_mask);
3472     header_size = _gvn.transform( new AddINode(hsize, mask) );
3473   }
3474 
3475   Node* elem_shift = NULL;
3476   if (layout_is_con) {
3477     int eshift = Klass::layout_helper_log2_element_size(layout_con);
3478     if (eshift != 0)
3479       elem_shift = intcon(eshift);
3480   } else {
3481     // There is no need to mask or shift this value.
3482     // The semantics of LShiftINode include an implicit mask to 0x1F.
3483     assert(Klass::_lh_log2_element_size_shift == 0, "use shift in place");
3484     elem_shift = layout_val;
3485   }
3486 
3487   // Transition to native address size for all offset calculations:
3488   Node* lengthx = ConvI2X(length);
3489   Node* headerx = ConvI2X(header_size);
3490 #ifdef _LP64
3491   { const TypeInt* tilen = _gvn.find_int_type(length);
3492     if (tilen != NULL && tilen->_lo < 0) {
3493       // Add a manual constraint to a positive range.  Cf. array_element_address.
3494       jint size_max = fast_size_limit;
3495       if (size_max > tilen->_hi)  size_max = tilen->_hi;
3496       const TypeInt* tlcon = TypeInt::make(0, size_max, Type::WidenMin);
3497 
3498       // Only do a narrow I2L conversion if the range check passed.
3499       IfNode* iff = new IfNode(control(), initial_slow_test, PROB_MIN, COUNT_UNKNOWN);
3500       _gvn.transform(iff);
3501       RegionNode* region = new RegionNode(3);
3502       _gvn.set_type(region, Type::CONTROL);
3503       lengthx = new PhiNode(region, TypeLong::LONG);
3504       _gvn.set_type(lengthx, TypeLong::LONG);
3505 
3506       // Range check passed. Use ConvI2L node with narrow type.
3507       Node* passed = IfFalse(iff);
3508       region->init_req(1, passed);
3509       // Make I2L conversion control dependent to prevent it from
3510       // floating above the range check during loop optimizations.
3511       lengthx->init_req(1, C->constrained_convI2L(&_gvn, length, tlcon, passed));
3512 
3513       // Range check failed. Use ConvI2L with wide type because length may be invalid.
3514       region->init_req(2, IfTrue(iff));
3515       lengthx->init_req(2, ConvI2X(length));
3516 
3517       set_control(region);
3518       record_for_igvn(region);
3519       record_for_igvn(lengthx);
3520     }
3521   }
3522 #endif
3523 
3524   // Combine header size (plus rounding) and body size.  Then round down.
3525   // This computation cannot overflow, because it is used only in two
3526   // places, one where the length is sharply limited, and the other
3527   // after a successful allocation.
3528   Node* abody = lengthx;
3529   if (elem_shift != NULL)
3530     abody     = _gvn.transform( new LShiftXNode(lengthx, elem_shift) );
3531   Node* size  = _gvn.transform( new AddXNode(headerx, abody) );
3532   if (round_mask != 0) {
3533     Node* mask = MakeConX(~round_mask);
3534     size       = _gvn.transform( new AndXNode(size, mask) );
3535   }
3536   // else if round_mask == 0, the size computation is self-rounding
3537 
3538   if (return_size_val != NULL) {
3539     // This is the size
3540     (*return_size_val) = size;
3541   }
3542 
3543   // Now generate allocation code
3544 
3545   // The entire memory state is needed for slow path of the allocation
3546   // since GC and deoptimization can happen.
3547   Node *mem = reset_memory();
3548   set_all_memory(mem); // Create new memory state
3549 
3550   if (initial_slow_test->is_Bool()) {
3551     // Hide it behind a CMoveI, or else PhaseIdealLoop::split_up will get sick.
3552     initial_slow_test = initial_slow_test->as_Bool()->as_int_value(&_gvn);
3553   }
3554 
3555   // Create the AllocateArrayNode and its result projections
3556   AllocateArrayNode* alloc
3557     = new AllocateArrayNode(C, AllocateArrayNode::alloc_type(TypeInt::INT),
3558                             control(), mem, i_o(),
3559                             size, klass_node,
3560                             initial_slow_test,
3561                             length);
3562 
3563   // Cast to correct type.  Note that the klass_node may be constant or not,
3564   // and in the latter case the actual array type will be inexact also.
3565   // (This happens via a non-constant argument to inline_native_newArray.)
3566   // In any case, the value of klass_node provides the desired array type.
3567   const TypeInt* length_type = _gvn.find_int_type(length);
3568   const TypeOopPtr* ary_type = _gvn.type(klass_node)->is_klassptr()->as_instance_type();
3569   if (ary_type->isa_aryptr() && length_type != NULL) {
3570     // Try to get a better type than POS for the size
3571     ary_type = ary_type->is_aryptr()->cast_to_size(length_type);
3572   }
3573 
3574   Node* javaoop = set_output_for_allocation(alloc, ary_type, deoptimize_on_exception);
3575 
3576   // Cast length on remaining path to be as narrow as possible
3577   if (map()->find_edge(length) >= 0) {
3578     Node* ccast = alloc->make_ideal_length(ary_type, &_gvn);
3579     if (ccast != length) {
3580       _gvn.set_type_bottom(ccast);
3581       record_for_igvn(ccast);
3582       replace_in_map(length, ccast);
3583     }
3584   }
3585 
3586   const TypeAryPtr* ary_ptr = ary_type->isa_aryptr();
3587   ciKlass* elem_klass = ary_ptr != NULL ? ary_ptr->klass()->as_array_klass()->element_klass() : NULL;
3588   if (elem_klass != NULL && elem_klass->is_valuetype()) {
3589     ciValueKlass* vk = elem_klass->as_value_klass();
3590     if (!vk->flatten_array()) {
3591       // Non-flattened value type arrays need to be initialized with default value type oops
3592       initialize_value_type_array(javaoop, length, elem_klass->as_value_klass(), nargs);
3593       InitializeNode* init = alloc->initialization();
3594       init->set_complete_with_arraycopy();
3595     }
3596   }
3597 
3598   return javaoop;
3599 }
3600 
3601 void GraphKit::initialize_value_type_array(Node* array, Node* length, ciValueKlass* vk, int nargs) {
3602   // Check for zero length
3603   Node* null_ctl = top();
3604   null_check_common(length, T_INT, false, &null_ctl, false);
3605   if (stopped()) {
3606     set_control(null_ctl); // Always zero
3607     return;
3608   }
3609 
3610   // Prepare for merging control and IO
3611   RegionNode* res_ctl = new RegionNode(3);
3612   res_ctl->init_req(1, null_ctl);
3613   gvn().set_type(res_ctl, Type::CONTROL);
3614   record_for_igvn(res_ctl);
3615   Node* res_io = PhiNode::make(res_ctl, i_o(), Type::ABIO);
3616   gvn().set_type(res_io, Type::ABIO);
3617   record_for_igvn(res_io);
3618 
3619   // TODO comment
3620   SafePointNode* loop_map = NULL;
3621   {
3622     PreserveJVMState pjvms(this);
3623     // Create default value type and store it to memory
3624     Node* oop = ValueTypeNode::make_default(gvn(), vk);
3625     oop = oop->as_ValueType()->store_to_memory(this);
3626 
3627     length = SubI(length, intcon(1));
3628     add_predicate(nargs);
3629     RegionNode* loop = new RegionNode(3);
3630     loop->init_req(1, control());
3631     gvn().set_type(loop, Type::CONTROL);
3632     record_for_igvn(loop);
3633 
3634     Node* index = new PhiNode(loop, TypeInt::INT);
3635     index->init_req(1, intcon(0));
3636     gvn().set_type(index, TypeInt::INT);
3637     record_for_igvn(index);
3638 
3639     // TODO explain why we need to capture all memory
3640     PhiNode* mem = new PhiNode(loop, Type::MEMORY, TypePtr::BOTTOM);
3641     mem->init_req(1, reset_memory());
3642     gvn().set_type(mem, Type::MEMORY);
3643     record_for_igvn(mem);
3644     set_control(loop);
3645     set_all_memory(mem);
3646     // Initialize array element
3647     Node* adr = array_element_address(array, index, T_OBJECT);
3648     const TypeOopPtr* elemtype = TypeValueTypePtr::make(TypePtr::NotNull, vk);
3649     Node* store = store_oop_to_array(control(), array, adr, TypeAryPtr::OOPS, oop, elemtype, T_OBJECT, MemNode::release);
3650 
3651     IfNode* iff = create_and_map_if(control(), Bool(CmpI(index, length), BoolTest::lt), PROB_FAIR, COUNT_UNKNOWN);
3652     loop->init_req(2, IfTrue(iff));
3653     mem->init_req(2, merged_memory());
3654     index->init_req(2, AddI(index, intcon(1)));
3655 
3656     res_ctl->init_req(2, IfFalse(iff));
3657     res_io->set_req(2, i_o());
3658     loop_map = stop();
3659   }
3660   // Set merged control, IO and memory
3661   set_control(res_ctl);
3662   set_i_o(res_io);
3663   merge_memory(loop_map->merged_memory(), res_ctl, 2);
3664 
3665   // Transform new memory Phis.
3666   for (MergeMemStream mms(merged_memory()); mms.next_non_empty();) {
3667     Node* phi = mms.memory();
3668     if (phi->is_Phi() && phi->in(0) == res_ctl) {
3669       mms.set_memory(gvn().transform(phi));
3670     }
3671   }
3672 }
3673 
3674 // The following "Ideal_foo" functions are placed here because they recognize
3675 // the graph shapes created by the functions immediately above.
3676 
3677 //---------------------------Ideal_allocation----------------------------------
3678 // Given an oop pointer or raw pointer, see if it feeds from an AllocateNode.
3679 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase) {
3680   if (ptr == NULL) {     // reduce dumb test in callers
3681     return NULL;
3682   }
3683   if (ptr->is_CheckCastPP()) { // strip only one raw-to-oop cast
3684     ptr = ptr->in(1);
3685     if (ptr == NULL) return NULL;
3686   }
3687   // Return NULL for allocations with several casts:
3688   //   j.l.reflect.Array.newInstance(jobject, jint)
3689   //   Object.clone()
3690   // to keep more precise type from last cast.
3691   if (ptr->is_Proj()) {
3692     Node* allo = ptr->in(0);
3693     if (allo != NULL && allo->is_Allocate()) {
3694       return allo->as_Allocate();
3695     }
3696   }
3697   // Report failure to match.
3698   return NULL;
3699 }
3700 
3701 // Fancy version which also strips off an offset (and reports it to caller).
3702 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase,
3703                                              intptr_t& offset) {
3704   Node* base = AddPNode::Ideal_base_and_offset(ptr, phase, offset);
3705   if (base == NULL)  return NULL;
3706   return Ideal_allocation(base, phase);
3707 }
3708 
3709 // Trace Initialize <- Proj[Parm] <- Allocate
3710 AllocateNode* InitializeNode::allocation() {
3711   Node* rawoop = in(InitializeNode::RawAddress);
3712   if (rawoop->is_Proj()) {
3713     Node* alloc = rawoop->in(0);
3714     if (alloc->is_Allocate()) {
3715       return alloc->as_Allocate();
3716     }
3717   }
3718   return NULL;
3719 }
3720 
3721 // Trace Allocate -> Proj[Parm] -> Initialize
3722 InitializeNode* AllocateNode::initialization() {
3723   ProjNode* rawoop = proj_out(AllocateNode::RawAddress);
3724   if (rawoop == NULL)  return NULL;
3725   for (DUIterator_Fast imax, i = rawoop->fast_outs(imax); i < imax; i++) {
3726     Node* init = rawoop->fast_out(i);
3727     if (init->is_Initialize()) {
3728       assert(init->as_Initialize()->allocation() == this, "2-way link");
3729       return init->as_Initialize();
3730     }
3731   }
3732   return NULL;
3733 }
3734 
3735 //----------------------------- loop predicates ---------------------------
3736 
3737 //------------------------------add_predicate_impl----------------------------
3738 void GraphKit::add_predicate_impl(Deoptimization::DeoptReason reason, int nargs) {
3739   // Too many traps seen?
3740   if (too_many_traps(reason)) {
3741 #ifdef ASSERT
3742     if (TraceLoopPredicate) {
3743       int tc = C->trap_count(reason);
3744       tty->print("too many traps=%s tcount=%d in ",
3745                     Deoptimization::trap_reason_name(reason), tc);
3746       method()->print(); // which method has too many predicate traps
3747       tty->cr();
3748     }
3749 #endif
3750     // We cannot afford to take more traps here,
3751     // do not generate predicate.
3752     return;
3753   }
3754 
3755   Node *cont    = _gvn.intcon(1);
3756   Node* opq     = _gvn.transform(new Opaque1Node(C, cont));
3757   Node *bol     = _gvn.transform(new Conv2BNode(opq));
3758   IfNode* iff   = create_and_map_if(control(), bol, PROB_MAX, COUNT_UNKNOWN);
3759   Node* iffalse = _gvn.transform(new IfFalseNode(iff));
3760   C->add_predicate_opaq(opq);
3761   {
3762     PreserveJVMState pjvms(this);
3763     set_control(iffalse);
3764     inc_sp(nargs);
3765     uncommon_trap(reason, Deoptimization::Action_maybe_recompile);
3766   }
3767   Node* iftrue = _gvn.transform(new IfTrueNode(iff));
3768   set_control(iftrue);
3769 }
3770 
3771 //------------------------------add_predicate---------------------------------
3772 void GraphKit::add_predicate(int nargs) {
3773   if (UseLoopPredicate) {
3774     add_predicate_impl(Deoptimization::Reason_predicate, nargs);
3775   }
3776   // loop's limit check predicate should be near the loop.
3777   add_predicate_impl(Deoptimization::Reason_loop_limit_check, nargs);
3778 }
3779 
3780 //----------------------------- store barriers ----------------------------
3781 #define __ ideal.
3782 
3783 void GraphKit::sync_kit(IdealKit& ideal) {
3784   set_all_memory(__ merged_memory());
3785   set_i_o(__ i_o());
3786   set_control(__ ctrl());
3787 }
3788 
3789 void GraphKit::final_sync(IdealKit& ideal) {
3790   // Final sync IdealKit and graphKit.
3791   sync_kit(ideal);
3792 }
3793 
3794 Node* GraphKit::byte_map_base_node() {
3795   // Get base of card map
3796   CardTableModRefBS* ct =
3797     barrier_set_cast<CardTableModRefBS>(Universe::heap()->barrier_set());
3798   assert(sizeof(*ct->byte_map_base) == sizeof(jbyte), "adjust users of this code");
3799   if (ct->byte_map_base != NULL) {
3800     return makecon(TypeRawPtr::make((address)ct->byte_map_base));
3801   } else {
3802     return null();
3803   }
3804 }
3805 
3806 // vanilla/CMS post barrier
3807 // Insert a write-barrier store.  This is to let generational GC work; we have
3808 // to flag all oop-stores before the next GC point.
3809 void GraphKit::write_barrier_post(Node* oop_store,
3810                                   Node* obj,
3811                                   Node* adr,
3812                                   uint  adr_idx,
3813                                   Node* val,
3814                                   bool use_precise) {
3815   // No store check needed if we're storing a NULL or an old object
3816   // (latter case is probably a string constant). The concurrent
3817   // mark sweep garbage collector, however, needs to have all nonNull
3818   // oop updates flagged via card-marks.
3819   if (val != NULL && val->is_Con()) {
3820     // must be either an oop or NULL
3821     const Type* t = val->bottom_type();
3822     if (t == TypePtr::NULL_PTR || t == Type::TOP)
3823       // stores of null never (?) need barriers
3824       return;
3825   }
3826 
3827   if (use_ReduceInitialCardMarks()
3828       && obj == just_allocated_object(control())) {
3829     // We can skip marks on a freshly-allocated object in Eden.
3830     // Keep this code in sync with new_store_pre_barrier() in runtime.cpp.
3831     // That routine informs GC to take appropriate compensating steps,
3832     // upon a slow-path allocation, so as to make this card-mark
3833     // elision safe.
3834     return;
3835   }
3836 
3837   if (!use_precise) {
3838     // All card marks for a (non-array) instance are in one place:
3839     adr = obj;
3840   }
3841   // (Else it's an array (or unknown), and we want more precise card marks.)
3842   assert(adr != NULL, "");
3843 
3844   IdealKit ideal(this, true);
3845 
3846   // Convert the pointer to an int prior to doing math on it
3847   Node* cast = __ CastPX(__ ctrl(), adr);
3848 
3849   // Divide by card size
3850   assert(Universe::heap()->barrier_set()->is_a(BarrierSet::CardTableModRef),
3851          "Only one we handle so far.");
3852   Node* card_offset = __ URShiftX( cast, __ ConI(CardTableModRefBS::card_shift) );
3853 
3854   // Combine card table base and card offset
3855   Node* card_adr = __ AddP(__ top(), byte_map_base_node(), card_offset );
3856 
3857   // Get the alias_index for raw card-mark memory
3858   int adr_type = Compile::AliasIdxRaw;
3859   Node*   zero = __ ConI(0); // Dirty card value
3860   BasicType bt = T_BYTE;
3861 
3862   if (UseConcMarkSweepGC && UseCondCardMark) {
3863     insert_mem_bar(Op_MemBarVolatile);   // StoreLoad barrier
3864     __ sync_kit(this);
3865   }
3866 
3867   if (UseCondCardMark) {
3868     // The classic GC reference write barrier is typically implemented
3869     // as a store into the global card mark table.  Unfortunately
3870     // unconditional stores can result in false sharing and excessive
3871     // coherence traffic as well as false transactional aborts.
3872     // UseCondCardMark enables MP "polite" conditional card mark
3873     // stores.  In theory we could relax the load from ctrl() to
3874     // no_ctrl, but that doesn't buy much latitude.
3875     Node* card_val = __ load( __ ctrl(), card_adr, TypeInt::BYTE, bt, adr_type);
3876     __ if_then(card_val, BoolTest::ne, zero);
3877   }
3878 
3879   // Smash zero into card
3880   if( !UseConcMarkSweepGC ) {
3881     __ store(__ ctrl(), card_adr, zero, bt, adr_type, MemNode::unordered);
3882   } else {
3883     // Specialized path for CM store barrier
3884     __ storeCM(__ ctrl(), card_adr, zero, oop_store, adr_idx, bt, adr_type);
3885   }
3886 
3887   if (UseCondCardMark) {
3888     __ end_if();
3889   }
3890 
3891   // Final sync IdealKit and GraphKit.
3892   final_sync(ideal);
3893 }
3894 /*
3895  * Determine if the G1 pre-barrier can be removed. The pre-barrier is
3896  * required by SATB to make sure all objects live at the start of the
3897  * marking are kept alive, all reference updates need to any previous
3898  * reference stored before writing.
3899  *
3900  * If the previous value is NULL there is no need to save the old value.
3901  * References that are NULL are filtered during runtime by the barrier
3902  * code to avoid unnecessary queuing.
3903  *
3904  * However in the case of newly allocated objects it might be possible to
3905  * prove that the reference about to be overwritten is NULL during compile
3906  * time and avoid adding the barrier code completely.
3907  *
3908  * The compiler needs to determine that the object in which a field is about
3909  * to be written is newly allocated, and that no prior store to the same field
3910  * has happened since the allocation.
3911  *
3912  * Returns true if the pre-barrier can be removed
3913  */
3914 bool GraphKit::g1_can_remove_pre_barrier(PhaseTransform* phase, Node* adr,
3915                                          BasicType bt, uint adr_idx) {
3916   intptr_t offset = 0;
3917   Node* base = AddPNode::Ideal_base_and_offset(adr, phase, offset);
3918   AllocateNode* alloc = AllocateNode::Ideal_allocation(base, phase);
3919 
3920   if (offset == Type::OffsetBot) {
3921     return false; // cannot unalias unless there are precise offsets
3922   }
3923 
3924   if (alloc == NULL) {
3925     return false; // No allocation found
3926   }
3927 
3928   intptr_t size_in_bytes = type2aelembytes(bt);
3929 
3930   Node* mem = memory(adr_idx); // start searching here...
3931 
3932   for (int cnt = 0; cnt < 50; cnt++) {
3933 
3934     if (mem->is_Store()) {
3935 
3936       Node* st_adr = mem->in(MemNode::Address);
3937       intptr_t st_offset = 0;
3938       Node* st_base = AddPNode::Ideal_base_and_offset(st_adr, phase, st_offset);
3939 
3940       if (st_base == NULL) {
3941         break; // inscrutable pointer
3942       }
3943 
3944       // Break we have found a store with same base and offset as ours so break
3945       if (st_base == base && st_offset == offset) {
3946         break;
3947       }
3948 
3949       if (st_offset != offset && st_offset != Type::OffsetBot) {
3950         const int MAX_STORE = BytesPerLong;
3951         if (st_offset >= offset + size_in_bytes ||
3952             st_offset <= offset - MAX_STORE ||
3953             st_offset <= offset - mem->as_Store()->memory_size()) {
3954           // Success:  The offsets are provably independent.
3955           // (You may ask, why not just test st_offset != offset and be done?
3956           // The answer is that stores of different sizes can co-exist
3957           // in the same sequence of RawMem effects.  We sometimes initialize
3958           // a whole 'tile' of array elements with a single jint or jlong.)
3959           mem = mem->in(MemNode::Memory);
3960           continue; // advance through independent store memory
3961         }
3962       }
3963 
3964       if (st_base != base
3965           && MemNode::detect_ptr_independence(base, alloc, st_base,
3966                                               AllocateNode::Ideal_allocation(st_base, phase),
3967                                               phase)) {
3968         // Success:  The bases are provably independent.
3969         mem = mem->in(MemNode::Memory);
3970         continue; // advance through independent store memory
3971       }
3972     } else if (mem->is_Proj() && mem->in(0)->is_Initialize()) {
3973 
3974       InitializeNode* st_init = mem->in(0)->as_Initialize();
3975       AllocateNode* st_alloc = st_init->allocation();
3976 
3977       // Make sure that we are looking at the same allocation site.
3978       // The alloc variable is guaranteed to not be null here from earlier check.
3979       if (alloc == st_alloc) {
3980         // Check that the initialization is storing NULL so that no previous store
3981         // has been moved up and directly write a reference
3982         Node* captured_store = st_init->find_captured_store(offset,
3983                                                             type2aelembytes(T_OBJECT),
3984                                                             phase);
3985         if (captured_store == NULL || captured_store == st_init->zero_memory()) {
3986           return true;
3987         }
3988       }
3989     }
3990 
3991     // Unless there is an explicit 'continue', we must bail out here,
3992     // because 'mem' is an inscrutable memory state (e.g., a call).
3993     break;
3994   }
3995 
3996   return false;
3997 }
3998 
3999 // G1 pre/post barriers
4000 void GraphKit::g1_write_barrier_pre(bool do_load,
4001                                     Node* obj,
4002                                     Node* adr,
4003                                     uint alias_idx,
4004                                     Node* val,
4005                                     const TypeOopPtr* val_type,
4006                                     Node* pre_val,
4007                                     BasicType bt) {
4008 
4009   // Some sanity checks
4010   // Note: val is unused in this routine.
4011 
4012   if (do_load) {
4013     // We need to generate the load of the previous value
4014     assert(obj != NULL, "must have a base");
4015     assert(adr != NULL, "where are loading from?");
4016     assert(pre_val == NULL, "loaded already?");
4017     assert(val_type != NULL, "need a type");
4018 
4019     if (use_ReduceInitialCardMarks()
4020         && g1_can_remove_pre_barrier(&_gvn, adr, bt, alias_idx)) {
4021       return;
4022     }
4023 
4024   } else {
4025     // In this case both val_type and alias_idx are unused.
4026     assert(pre_val != NULL, "must be loaded already");
4027     // Nothing to be done if pre_val is null.
4028     if (pre_val->bottom_type() == TypePtr::NULL_PTR) return;
4029     assert(pre_val->bottom_type()->basic_type() == T_OBJECT, "or we shouldn't be here");
4030   }
4031   assert(bt == T_OBJECT || bt == T_VALUETYPE, "or we shouldn't be here");
4032 
4033   IdealKit ideal(this, true);
4034 
4035   Node* tls = __ thread(); // ThreadLocalStorage
4036 
4037   Node* no_ctrl = NULL;
4038   Node* no_base = __ top();
4039   Node* zero  = __ ConI(0);
4040   Node* zeroX = __ ConX(0);
4041 
4042   float likely  = PROB_LIKELY(0.999);
4043   float unlikely  = PROB_UNLIKELY(0.999);
4044 
4045   BasicType active_type = in_bytes(SATBMarkQueue::byte_width_of_active()) == 4 ? T_INT : T_BYTE;
4046   assert(in_bytes(SATBMarkQueue::byte_width_of_active()) == 4 || in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "flag width");
4047 
4048   // Offsets into the thread
4049   const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() +  // 648
4050                                           SATBMarkQueue::byte_offset_of_active());
4051   const int index_offset   = in_bytes(JavaThread::satb_mark_queue_offset() +  // 656
4052                                           SATBMarkQueue::byte_offset_of_index());
4053   const int buffer_offset  = in_bytes(JavaThread::satb_mark_queue_offset() +  // 652
4054                                           SATBMarkQueue::byte_offset_of_buf());
4055 
4056   // Now the actual pointers into the thread
4057   Node* marking_adr = __ AddP(no_base, tls, __ ConX(marking_offset));
4058   Node* buffer_adr  = __ AddP(no_base, tls, __ ConX(buffer_offset));
4059   Node* index_adr   = __ AddP(no_base, tls, __ ConX(index_offset));
4060 
4061   // Now some of the values
4062   Node* marking = __ load(__ ctrl(), marking_adr, TypeInt::INT, active_type, Compile::AliasIdxRaw);
4063 
4064   // if (!marking)
4065   __ if_then(marking, BoolTest::ne, zero, unlikely); {
4066     BasicType index_bt = TypeX_X->basic_type();
4067     assert(sizeof(size_t) == type2aelembytes(index_bt), "Loading G1 SATBMarkQueue::_index with wrong size.");
4068     Node* index   = __ load(__ ctrl(), index_adr, TypeX_X, index_bt, Compile::AliasIdxRaw);
4069 
4070     if (do_load) {
4071       // load original value
4072       // alias_idx correct??
4073       pre_val = __ load(__ ctrl(), adr, val_type, bt, alias_idx);
4074     }
4075 
4076     // if (pre_val != NULL)
4077     __ if_then(pre_val, BoolTest::ne, null()); {
4078       Node* buffer  = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
4079 
4080       // is the queue for this thread full?
4081       __ if_then(index, BoolTest::ne, zeroX, likely); {
4082 
4083         // decrement the index
4084         Node* next_index = _gvn.transform(new SubXNode(index, __ ConX(sizeof(intptr_t))));
4085 
4086         // Now get the buffer location we will log the previous value into and store it
4087         Node *log_addr = __ AddP(no_base, buffer, next_index);
4088         __ store(__ ctrl(), log_addr, pre_val, T_OBJECT, Compile::AliasIdxRaw, MemNode::unordered);
4089         // update the index
4090         __ store(__ ctrl(), index_adr, next_index, index_bt, Compile::AliasIdxRaw, MemNode::unordered);
4091 
4092       } __ else_(); {
4093 
4094         // logging buffer is full, call the runtime
4095         const TypeFunc *tf = OptoRuntime::g1_wb_pre_Type();
4096         __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_pre), "g1_wb_pre", pre_val, tls);
4097       } __ end_if();  // (!index)
4098     } __ end_if();  // (pre_val != NULL)
4099   } __ end_if();  // (!marking)
4100 
4101   // Final sync IdealKit and GraphKit.
4102   final_sync(ideal);
4103 }
4104 
4105 /*
4106  * G1 similar to any GC with a Young Generation requires a way to keep track of
4107  * references from Old Generation to Young Generation to make sure all live
4108  * objects are found. G1 also requires to keep track of object references
4109  * between different regions to enable evacuation of old regions, which is done
4110  * as part of mixed collections. References are tracked in remembered sets and
4111  * is continuously updated as reference are written to with the help of the
4112  * post-barrier.
4113  *
4114  * To reduce the number of updates to the remembered set the post-barrier
4115  * filters updates to fields in objects located in the Young Generation,
4116  * the same region as the reference, when the NULL is being written or
4117  * if the card is already marked as dirty by an earlier write.
4118  *
4119  * Under certain circumstances it is possible to avoid generating the
4120  * post-barrier completely if it is possible during compile time to prove
4121  * the object is newly allocated and that no safepoint exists between the
4122  * allocation and the store.
4123  *
4124  * In the case of slow allocation the allocation code must handle the barrier
4125  * as part of the allocation in the case the allocated object is not located
4126  * in the nursery, this would happen for humongous objects. This is similar to
4127  * how CMS is required to handle this case, see the comments for the method
4128  * CollectedHeap::new_store_pre_barrier and OptoRuntime::new_store_pre_barrier.
4129  * A deferred card mark is required for these objects and handled in the above
4130  * mentioned methods.
4131  *
4132  * Returns true if the post barrier can be removed
4133  */
4134 bool GraphKit::g1_can_remove_post_barrier(PhaseTransform* phase, Node* store,
4135                                           Node* adr) {
4136   intptr_t      offset = 0;
4137   Node*         base   = AddPNode::Ideal_base_and_offset(adr, phase, offset);
4138   AllocateNode* alloc  = AllocateNode::Ideal_allocation(base, phase);
4139 
4140   if (offset == Type::OffsetBot) {
4141     return false; // cannot unalias unless there are precise offsets
4142   }
4143 
4144   if (alloc == NULL) {
4145      return false; // No allocation found
4146   }
4147 
4148   // Start search from Store node
4149   Node* mem = store->in(MemNode::Control);
4150   if (mem->is_Proj() && mem->in(0)->is_Initialize()) {
4151 
4152     InitializeNode* st_init = mem->in(0)->as_Initialize();
4153     AllocateNode*  st_alloc = st_init->allocation();
4154 
4155     // Make sure we are looking at the same allocation
4156     if (alloc == st_alloc) {
4157       return true;
4158     }
4159   }
4160 
4161   return false;
4162 }
4163 
4164 //
4165 // Update the card table and add card address to the queue
4166 //
4167 void GraphKit::g1_mark_card(IdealKit& ideal,
4168                             Node* card_adr,
4169                             Node* oop_store,
4170                             uint oop_alias_idx,
4171                             Node* index,
4172                             Node* index_adr,
4173                             Node* buffer,
4174                             const TypeFunc* tf) {
4175 
4176   Node* zero  = __ ConI(0);
4177   Node* zeroX = __ ConX(0);
4178   Node* no_base = __ top();
4179   BasicType card_bt = T_BYTE;
4180   // Smash zero into card. MUST BE ORDERED WRT TO STORE
4181   __ storeCM(__ ctrl(), card_adr, zero, oop_store, oop_alias_idx, card_bt, Compile::AliasIdxRaw);
4182 
4183   //  Now do the queue work
4184   __ if_then(index, BoolTest::ne, zeroX); {
4185 
4186     Node* next_index = _gvn.transform(new SubXNode(index, __ ConX(sizeof(intptr_t))));
4187     Node* log_addr = __ AddP(no_base, buffer, next_index);
4188 
4189     // Order, see storeCM.
4190     __ store(__ ctrl(), log_addr, card_adr, T_ADDRESS, Compile::AliasIdxRaw, MemNode::unordered);
4191     __ store(__ ctrl(), index_adr, next_index, TypeX_X->basic_type(), Compile::AliasIdxRaw, MemNode::unordered);
4192 
4193   } __ else_(); {
4194     __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_post), "g1_wb_post", card_adr, __ thread());
4195   } __ end_if();
4196 
4197 }
4198 
4199 void GraphKit::g1_write_barrier_post(Node* oop_store,
4200                                      Node* obj,
4201                                      Node* adr,
4202                                      uint alias_idx,
4203                                      Node* val,
4204                                      BasicType bt,
4205                                      bool use_precise) {
4206   // If we are writing a NULL then we need no post barrier
4207 
4208   if (val != NULL && val->is_Con() && val->bottom_type() == TypePtr::NULL_PTR) {
4209     // Must be NULL
4210     const Type* t = val->bottom_type();
4211     assert(t == Type::TOP || t == TypePtr::NULL_PTR, "must be NULL");
4212     // No post barrier if writing NULLx
4213     return;
4214   }
4215 
4216   if (use_ReduceInitialCardMarks() && obj == just_allocated_object(control())) {
4217     // We can skip marks on a freshly-allocated object in Eden.
4218     // Keep this code in sync with new_store_pre_barrier() in runtime.cpp.
4219     // That routine informs GC to take appropriate compensating steps,
4220     // upon a slow-path allocation, so as to make this card-mark
4221     // elision safe.
4222     return;
4223   }
4224 
4225   if (use_ReduceInitialCardMarks()
4226       && g1_can_remove_post_barrier(&_gvn, oop_store, adr)) {
4227     return;
4228   }
4229 
4230   if (!use_precise) {
4231     // All card marks for a (non-array) instance are in one place:
4232     adr = obj;
4233   }
4234   // (Else it's an array (or unknown), and we want more precise card marks.)
4235   assert(adr != NULL, "");
4236 
4237   IdealKit ideal(this, true);
4238 
4239   Node* tls = __ thread(); // ThreadLocalStorage
4240 
4241   Node* no_base = __ top();
4242   float likely  = PROB_LIKELY(0.999);
4243   float unlikely  = PROB_UNLIKELY(0.999);
4244   Node* young_card = __ ConI((jint)G1SATBCardTableModRefBS::g1_young_card_val());
4245   Node* dirty_card = __ ConI((jint)CardTableModRefBS::dirty_card_val());
4246   Node* zeroX = __ ConX(0);
4247 
4248   // Get the alias_index for raw card-mark memory
4249   const TypePtr* card_type = TypeRawPtr::BOTTOM;
4250 
4251   const TypeFunc *tf = OptoRuntime::g1_wb_post_Type();
4252 
4253   // Offsets into the thread
4254   const int index_offset  = in_bytes(JavaThread::dirty_card_queue_offset() +
4255                                      DirtyCardQueue::byte_offset_of_index());
4256   const int buffer_offset = in_bytes(JavaThread::dirty_card_queue_offset() +
4257                                      DirtyCardQueue::byte_offset_of_buf());
4258 
4259   // Pointers into the thread
4260 
4261   Node* buffer_adr = __ AddP(no_base, tls, __ ConX(buffer_offset));
4262   Node* index_adr =  __ AddP(no_base, tls, __ ConX(index_offset));
4263 
4264   // Now some values
4265   // Use ctrl to avoid hoisting these values past a safepoint, which could
4266   // potentially reset these fields in the JavaThread.
4267   Node* index  = __ load(__ ctrl(), index_adr, TypeX_X, TypeX_X->basic_type(), Compile::AliasIdxRaw);
4268   Node* buffer = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
4269 
4270   // Convert the store obj pointer to an int prior to doing math on it
4271   // Must use ctrl to prevent "integerized oop" existing across safepoint
4272   Node* cast =  __ CastPX(__ ctrl(), adr);
4273 
4274   // Divide pointer by card size
4275   Node* card_offset = __ URShiftX( cast, __ ConI(CardTableModRefBS::card_shift) );
4276 
4277   // Combine card table base and card offset
4278   Node* card_adr = __ AddP(no_base, byte_map_base_node(), card_offset );
4279 
4280   // If we know the value being stored does it cross regions?
4281 
4282   if (val != NULL) {
4283     // Does the store cause us to cross regions?
4284 
4285     // Should be able to do an unsigned compare of region_size instead of
4286     // and extra shift. Do we have an unsigned compare??
4287     // Node* region_size = __ ConI(1 << HeapRegion::LogOfHRGrainBytes);
4288     Node* xor_res =  __ URShiftX ( __ XorX( cast,  __ CastPX(__ ctrl(), val)), __ ConI(HeapRegion::LogOfHRGrainBytes));
4289 
4290     // if (xor_res == 0) same region so skip
4291     __ if_then(xor_res, BoolTest::ne, zeroX); {
4292 
4293       // No barrier if we are storing a NULL
4294       __ if_then(val, BoolTest::ne, null(), unlikely); {
4295 
4296         // Ok must mark the card if not already dirty
4297 
4298         // load the original value of the card
4299         Node* card_val = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
4300 
4301         __ if_then(card_val, BoolTest::ne, young_card); {
4302           sync_kit(ideal);
4303           // Use Op_MemBarVolatile to achieve the effect of a StoreLoad barrier.
4304           insert_mem_bar(Op_MemBarVolatile, oop_store);
4305           __ sync_kit(this);
4306 
4307           Node* card_val_reload = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
4308           __ if_then(card_val_reload, BoolTest::ne, dirty_card); {
4309             g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
4310           } __ end_if();
4311         } __ end_if();
4312       } __ end_if();
4313     } __ end_if();
4314   } else {
4315     // The Object.clone() intrinsic uses this path if !ReduceInitialCardMarks.
4316     // We don't need a barrier here if the destination is a newly allocated object
4317     // in Eden. Otherwise, GC verification breaks because we assume that cards in Eden
4318     // are set to 'g1_young_gen' (see G1SATBCardTableModRefBS::verify_g1_young_region()).
4319     assert(!use_ReduceInitialCardMarks(), "can only happen with card marking");
4320     Node* card_val = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
4321     __ if_then(card_val, BoolTest::ne, young_card); {
4322       g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
4323     } __ end_if();
4324   }
4325 
4326   // Final sync IdealKit and GraphKit.
4327   final_sync(ideal);
4328 }
4329 #undef __
4330 
4331 
4332 Node* GraphKit::load_String_length(Node* ctrl, Node* str) {
4333   Node* len = load_array_length(load_String_value(ctrl, str));
4334   Node* coder = load_String_coder(ctrl, str);
4335   // Divide length by 2 if coder is UTF16
4336   return _gvn.transform(new RShiftINode(len, coder));
4337 }
4338 
4339 Node* GraphKit::load_String_value(Node* ctrl, Node* str) {
4340   int value_offset = java_lang_String::value_offset_in_bytes();
4341   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4342                                                      false, NULL, Type::Offset(0));
4343   const TypePtr* value_field_type = string_type->add_offset(value_offset);
4344   const TypeAryPtr* value_type = TypeAryPtr::make(TypePtr::NotNull,
4345                                                   TypeAry::make(TypeInt::BYTE, TypeInt::POS),
4346                                                   ciTypeArrayKlass::make(T_BYTE), true, Type::Offset(0));
4347   int value_field_idx = C->get_alias_index(value_field_type);
4348   Node* load = make_load(ctrl, basic_plus_adr(str, str, value_offset),
4349                          value_type, T_OBJECT, value_field_idx, MemNode::unordered);
4350   // String.value field is known to be @Stable.
4351   if (UseImplicitStableValues) {
4352     load = cast_array_to_stable(load, value_type);
4353   }
4354   return load;
4355 }
4356 
4357 Node* GraphKit::load_String_coder(Node* ctrl, Node* str) {
4358   if (!CompactStrings) {
4359     return intcon(java_lang_String::CODER_UTF16);
4360   }
4361   int coder_offset = java_lang_String::coder_offset_in_bytes();
4362   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4363                                                      false, NULL, Type::Offset(0));
4364   const TypePtr* coder_field_type = string_type->add_offset(coder_offset);
4365   int coder_field_idx = C->get_alias_index(coder_field_type);
4366   return make_load(ctrl, basic_plus_adr(str, str, coder_offset),
4367                    TypeInt::BYTE, T_BYTE, coder_field_idx, MemNode::unordered);
4368 }
4369 
4370 void GraphKit::store_String_value(Node* ctrl, Node* str, Node* value) {
4371   int value_offset = java_lang_String::value_offset_in_bytes();
4372   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4373                                                      false, NULL, Type::Offset(0));
4374   const TypePtr* value_field_type = string_type->add_offset(value_offset);
4375   store_oop_to_object(ctrl, str,  basic_plus_adr(str, value_offset), value_field_type,
4376       value, TypeAryPtr::BYTES, T_OBJECT, MemNode::unordered);
4377 }
4378 
4379 void GraphKit::store_String_coder(Node* ctrl, Node* str, Node* value) {
4380   int coder_offset = java_lang_String::coder_offset_in_bytes();
4381   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4382                                                      false, NULL, Type::Offset(0));
4383   const TypePtr* coder_field_type = string_type->add_offset(coder_offset);
4384   int coder_field_idx = C->get_alias_index(coder_field_type);
4385   store_to_memory(ctrl, basic_plus_adr(str, coder_offset),
4386                   value, T_BYTE, coder_field_idx, MemNode::unordered);
4387 }
4388 
4389 // Capture src and dst memory state with a MergeMemNode
4390 Node* GraphKit::capture_memory(const TypePtr* src_type, const TypePtr* dst_type) {
4391   if (src_type == dst_type) {
4392     // Types are equal, we don't need a MergeMemNode
4393     return memory(src_type);
4394   }
4395   MergeMemNode* merge = MergeMemNode::make(map()->memory());
4396   record_for_igvn(merge); // fold it up later, if possible
4397   int src_idx = C->get_alias_index(src_type);
4398   int dst_idx = C->get_alias_index(dst_type);
4399   merge->set_memory_at(src_idx, memory(src_idx));
4400   merge->set_memory_at(dst_idx, memory(dst_idx));
4401   return merge;
4402 }
4403 
4404 Node* GraphKit::compress_string(Node* src, const TypeAryPtr* src_type, Node* dst, Node* count) {
4405   assert(Matcher::match_rule_supported(Op_StrCompressedCopy), "Intrinsic not supported");
4406   assert(src_type == TypeAryPtr::BYTES || src_type == TypeAryPtr::CHARS, "invalid source type");
4407   // If input and output memory types differ, capture both states to preserve
4408   // the dependency between preceding and subsequent loads/stores.
4409   // For example, the following program:
4410   //  StoreB
4411   //  compress_string
4412   //  LoadB
4413   // has this memory graph (use->def):
4414   //  LoadB -> compress_string -> CharMem
4415   //             ... -> StoreB -> ByteMem
4416   // The intrinsic hides the dependency between LoadB and StoreB, causing
4417   // the load to read from memory not containing the result of the StoreB.
4418   // The correct memory graph should look like this:
4419   //  LoadB -> compress_string -> MergeMem(CharMem, StoreB(ByteMem))
4420   Node* mem = capture_memory(src_type, TypeAryPtr::BYTES);
4421   StrCompressedCopyNode* str = new StrCompressedCopyNode(control(), mem, src, dst, count);
4422   Node* res_mem = _gvn.transform(new SCMemProjNode(str));
4423   set_memory(res_mem, TypeAryPtr::BYTES);
4424   return str;
4425 }
4426 
4427 void GraphKit::inflate_string(Node* src, Node* dst, const TypeAryPtr* dst_type, Node* count) {
4428   assert(Matcher::match_rule_supported(Op_StrInflatedCopy), "Intrinsic not supported");
4429   assert(dst_type == TypeAryPtr::BYTES || dst_type == TypeAryPtr::CHARS, "invalid dest type");
4430   // Capture src and dst memory (see comment in 'compress_string').
4431   Node* mem = capture_memory(TypeAryPtr::BYTES, dst_type);
4432   StrInflatedCopyNode* str = new StrInflatedCopyNode(control(), mem, src, dst, count);
4433   set_memory(_gvn.transform(str), dst_type);
4434 }
4435 
4436 void GraphKit::inflate_string_slow(Node* src, Node* dst, Node* start, Node* count) {
4437   /**
4438    * int i_char = start;
4439    * for (int i_byte = 0; i_byte < count; i_byte++) {
4440    *   dst[i_char++] = (char)(src[i_byte] & 0xff);
4441    * }
4442    */
4443   add_predicate();
4444   RegionNode* head = new RegionNode(3);
4445   head->init_req(1, control());
4446   gvn().set_type(head, Type::CONTROL);
4447   record_for_igvn(head);
4448 
4449   Node* i_byte = new PhiNode(head, TypeInt::INT);
4450   i_byte->init_req(1, intcon(0));
4451   gvn().set_type(i_byte, TypeInt::INT);
4452   record_for_igvn(i_byte);
4453 
4454   Node* i_char = new PhiNode(head, TypeInt::INT);
4455   i_char->init_req(1, start);
4456   gvn().set_type(i_char, TypeInt::INT);
4457   record_for_igvn(i_char);
4458 
4459   Node* mem = PhiNode::make(head, memory(TypeAryPtr::BYTES), Type::MEMORY, TypeAryPtr::BYTES);
4460   gvn().set_type(mem, Type::MEMORY);
4461   record_for_igvn(mem);
4462   set_control(head);
4463   set_memory(mem, TypeAryPtr::BYTES);
4464   Node* ch = load_array_element(control(), src, i_byte, TypeAryPtr::BYTES);
4465   Node* st = store_to_memory(control(), array_element_address(dst, i_char, T_BYTE),
4466                              AndI(ch, intcon(0xff)), T_CHAR, TypeAryPtr::BYTES, MemNode::unordered,
4467                              false, false, true /* mismatched */);
4468 
4469   IfNode* iff = create_and_map_if(head, Bool(CmpI(i_byte, count), BoolTest::lt), PROB_FAIR, COUNT_UNKNOWN);
4470   head->init_req(2, IfTrue(iff));
4471   mem->init_req(2, st);
4472   i_byte->init_req(2, AddI(i_byte, intcon(1)));
4473   i_char->init_req(2, AddI(i_char, intcon(2)));
4474 
4475   set_control(IfFalse(iff));
4476   set_memory(st, TypeAryPtr::BYTES);
4477 }
4478 
4479 Node* GraphKit::make_constant_from_field(ciField* field, Node* obj) {
4480   if (!field->is_constant()) {
4481     return NULL; // Field not marked as constant.
4482   }
4483   ciInstance* holder = NULL;
4484   if (!field->is_static()) {
4485     ciObject* const_oop = obj->bottom_type()->is_oopptr()->const_oop();
4486     if (const_oop != NULL && const_oop->is_instance()) {
4487       holder = const_oop->as_instance();
4488     }
4489   }
4490   const Type* con_type = Type::make_constant_from_field(field, holder, field->layout_type(),
4491                                                         /*is_unsigned_load=*/false);
4492   if (con_type != NULL) {
4493     Node* con = makecon(con_type);
4494     if (field->layout_type() == T_VALUETYPE) {
4495       // Load value type from constant oop
4496       con = ValueTypeNode::make(gvn(), map()->memory(), con);
4497     }
4498     return con;
4499   }
4500   return NULL;
4501 }
4502 
4503 Node* GraphKit::cast_array_to_stable(Node* ary, const TypeAryPtr* ary_type) {
4504   // Reify the property as a CastPP node in Ideal graph to comply with monotonicity
4505   // assumption of CCP analysis.
4506   return _gvn.transform(new CastPPNode(ary, ary_type->cast_to_stable(true)));
4507 }
--- EOF ---