1 /*
   2  * Copyright (c) 2001, 2019, 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 "ci/ciUtilities.hpp"
  27 #include "compiler/compileLog.hpp"
  28 #include "gc/shared/barrierSet.hpp"
  29 #include "gc/shared/c2/barrierSetC2.hpp"
  30 #include "interpreter/interpreter.hpp"
  31 #include "memory/resourceArea.hpp"
  32 #include "opto/addnode.hpp"
  33 #include "opto/castnode.hpp"
  34 #include "opto/convertnode.hpp"
  35 #include "opto/graphKit.hpp"
  36 #include "opto/idealKit.hpp"
  37 #include "opto/intrinsicnode.hpp"
  38 #include "opto/locknode.hpp"
  39 #include "opto/machnode.hpp"
  40 #include "opto/opaquenode.hpp"
  41 #include "opto/parse.hpp"
  42 #include "opto/rootnode.hpp"
  43 #include "opto/runtime.hpp"
  44 #include "runtime/deoptimization.hpp"
  45 #include "runtime/sharedRuntime.hpp"
  46 
  47 //----------------------------GraphKit-----------------------------------------
  48 // Main utility constructor.
  49 GraphKit::GraphKit(JVMState* jvms)
  50   : Phase(Phase::Parser),
  51     _env(C->env()),
  52     _gvn(*C->initial_gvn()),
  53     _barrier_set(BarrierSet::barrier_set()->barrier_set_c2())
  54 {
  55   _exceptions = jvms->map()->next_exception();
  56   if (_exceptions != NULL)  jvms->map()->set_next_exception(NULL);
  57   set_jvms(jvms);
  58 }
  59 
  60 // Private constructor for parser.
  61 GraphKit::GraphKit()
  62   : Phase(Phase::Parser),
  63     _env(C->env()),
  64     _gvn(*C->initial_gvn()),
  65     _barrier_set(BarrierSet::barrier_set()->barrier_set_c2())
  66 {
  67   _exceptions = NULL;
  68   set_map(NULL);
  69   debug_only(_sp = -99);
  70   debug_only(set_bci(-99));
  71 }
  72 
  73 
  74 
  75 //---------------------------clean_stack---------------------------------------
  76 // Clear away rubbish from the stack area of the JVM state.
  77 // This destroys any arguments that may be waiting on the stack.
  78 void GraphKit::clean_stack(int from_sp) {
  79   SafePointNode* map      = this->map();
  80   JVMState*      jvms     = this->jvms();
  81   int            stk_size = jvms->stk_size();
  82   int            stkoff   = jvms->stkoff();
  83   Node*          top      = this->top();
  84   for (int i = from_sp; i < stk_size; i++) {
  85     if (map->in(stkoff + i) != top) {
  86       map->set_req(stkoff + i, top);
  87     }
  88   }
  89 }
  90 
  91 
  92 //--------------------------------sync_jvms-----------------------------------
  93 // Make sure our current jvms agrees with our parse state.
  94 JVMState* GraphKit::sync_jvms() const {
  95   JVMState* jvms = this->jvms();
  96   jvms->set_bci(bci());       // Record the new bci in the JVMState
  97   jvms->set_sp(sp());         // Record the new sp in the JVMState
  98   assert(jvms_in_sync(), "jvms is now in sync");
  99   return jvms;
 100 }
 101 
 102 //--------------------------------sync_jvms_for_reexecute---------------------
 103 // Make sure our current jvms agrees with our parse state.  This version
 104 // uses the reexecute_sp for reexecuting bytecodes.
 105 JVMState* GraphKit::sync_jvms_for_reexecute() {
 106   JVMState* jvms = this->jvms();
 107   jvms->set_bci(bci());          // Record the new bci in the JVMState
 108   jvms->set_sp(reexecute_sp());  // Record the new sp in the JVMState
 109   return jvms;
 110 }
 111 
 112 #ifdef ASSERT
 113 bool GraphKit::jvms_in_sync() const {
 114   Parse* parse = is_Parse();
 115   if (parse == NULL) {
 116     if (bci() !=      jvms()->bci())          return false;
 117     if (sp()  != (int)jvms()->sp())           return false;
 118     return true;
 119   }
 120   if (jvms()->method() != parse->method())    return false;
 121   if (jvms()->bci()    != parse->bci())       return false;
 122   int jvms_sp = jvms()->sp();
 123   if (jvms_sp          != parse->sp())        return false;
 124   int jvms_depth = jvms()->depth();
 125   if (jvms_depth       != parse->depth())     return false;
 126   return true;
 127 }
 128 
 129 // Local helper checks for special internal merge points
 130 // used to accumulate and merge exception states.
 131 // They are marked by the region's in(0) edge being the map itself.
 132 // Such merge points must never "escape" into the parser at large,
 133 // until they have been handed to gvn.transform.
 134 static bool is_hidden_merge(Node* reg) {
 135   if (reg == NULL)  return false;
 136   if (reg->is_Phi()) {
 137     reg = reg->in(0);
 138     if (reg == NULL)  return false;
 139   }
 140   return reg->is_Region() && reg->in(0) != NULL && reg->in(0)->is_Root();
 141 }
 142 
 143 void GraphKit::verify_map() const {
 144   if (map() == NULL)  return;  // null map is OK
 145   assert(map()->req() <= jvms()->endoff(), "no extra garbage on map");
 146   assert(!map()->has_exceptions(),    "call add_exception_states_from 1st");
 147   assert(!is_hidden_merge(control()), "call use_exception_state, not set_map");
 148 }
 149 
 150 void GraphKit::verify_exception_state(SafePointNode* ex_map) {
 151   assert(ex_map->next_exception() == NULL, "not already part of a chain");
 152   assert(has_saved_ex_oop(ex_map), "every exception state has an ex_oop");
 153 }
 154 #endif
 155 
 156 //---------------------------stop_and_kill_map---------------------------------
 157 // Set _map to NULL, signalling a stop to further bytecode execution.
 158 // First smash the current map's control to a constant, to mark it dead.
 159 void GraphKit::stop_and_kill_map() {
 160   SafePointNode* dead_map = stop();
 161   if (dead_map != NULL) {
 162     dead_map->disconnect_inputs(NULL, C); // Mark the map as killed.
 163     assert(dead_map->is_killed(), "must be so marked");
 164   }
 165 }
 166 
 167 
 168 //--------------------------------stopped--------------------------------------
 169 // Tell if _map is NULL, or control is top.
 170 bool GraphKit::stopped() {
 171   if (map() == NULL)           return true;
 172   else if (control() == top()) return true;
 173   else                         return false;
 174 }
 175 
 176 
 177 //-----------------------------has_ex_handler----------------------------------
 178 // Tell if this method or any caller method has exception handlers.
 179 bool GraphKit::has_ex_handler() {
 180   for (JVMState* jvmsp = jvms(); jvmsp != NULL; jvmsp = jvmsp->caller()) {
 181     if (jvmsp->has_method() && jvmsp->method()->has_exception_handlers()) {
 182       return true;
 183     }
 184   }
 185   return false;
 186 }
 187 
 188 //------------------------------save_ex_oop------------------------------------
 189 // Save an exception without blowing stack contents or other JVM state.
 190 void GraphKit::set_saved_ex_oop(SafePointNode* ex_map, Node* ex_oop) {
 191   assert(!has_saved_ex_oop(ex_map), "clear ex-oop before setting again");
 192   ex_map->add_req(ex_oop);
 193   debug_only(verify_exception_state(ex_map));
 194 }
 195 
 196 inline static Node* common_saved_ex_oop(SafePointNode* ex_map, bool clear_it) {
 197   assert(GraphKit::has_saved_ex_oop(ex_map), "ex_oop must be there");
 198   Node* ex_oop = ex_map->in(ex_map->req()-1);
 199   if (clear_it)  ex_map->del_req(ex_map->req()-1);
 200   return ex_oop;
 201 }
 202 
 203 //-----------------------------saved_ex_oop------------------------------------
 204 // Recover a saved exception from its map.
 205 Node* GraphKit::saved_ex_oop(SafePointNode* ex_map) {
 206   return common_saved_ex_oop(ex_map, false);
 207 }
 208 
 209 //--------------------------clear_saved_ex_oop---------------------------------
 210 // Erase a previously saved exception from its map.
 211 Node* GraphKit::clear_saved_ex_oop(SafePointNode* ex_map) {
 212   return common_saved_ex_oop(ex_map, true);
 213 }
 214 
 215 #ifdef ASSERT
 216 //---------------------------has_saved_ex_oop----------------------------------
 217 // Erase a previously saved exception from its map.
 218 bool GraphKit::has_saved_ex_oop(SafePointNode* ex_map) {
 219   return ex_map->req() == ex_map->jvms()->endoff()+1;
 220 }
 221 #endif
 222 
 223 //-------------------------make_exception_state--------------------------------
 224 // Turn the current JVM state into an exception state, appending the ex_oop.
 225 SafePointNode* GraphKit::make_exception_state(Node* ex_oop) {
 226   sync_jvms();
 227   SafePointNode* ex_map = stop();  // do not manipulate this map any more
 228   set_saved_ex_oop(ex_map, ex_oop);
 229   return ex_map;
 230 }
 231 
 232 
 233 //--------------------------add_exception_state--------------------------------
 234 // Add an exception to my list of exceptions.
 235 void GraphKit::add_exception_state(SafePointNode* ex_map) {
 236   if (ex_map == NULL || ex_map->control() == top()) {
 237     return;
 238   }
 239 #ifdef ASSERT
 240   verify_exception_state(ex_map);
 241   if (has_exceptions()) {
 242     assert(ex_map->jvms()->same_calls_as(_exceptions->jvms()), "all collected exceptions must come from the same place");
 243   }
 244 #endif
 245 
 246   // If there is already an exception of exactly this type, merge with it.
 247   // In particular, null-checks and other low-level exceptions common up here.
 248   Node*       ex_oop  = saved_ex_oop(ex_map);
 249   const Type* ex_type = _gvn.type(ex_oop);
 250   if (ex_oop == top()) {
 251     // No action needed.
 252     return;
 253   }
 254   assert(ex_type->isa_instptr(), "exception must be an instance");
 255   for (SafePointNode* e2 = _exceptions; e2 != NULL; e2 = e2->next_exception()) {
 256     const Type* ex_type2 = _gvn.type(saved_ex_oop(e2));
 257     // We check sp also because call bytecodes can generate exceptions
 258     // both before and after arguments are popped!
 259     if (ex_type2 == ex_type
 260         && e2->_jvms->sp() == ex_map->_jvms->sp()) {
 261       combine_exception_states(ex_map, e2);
 262       return;
 263     }
 264   }
 265 
 266   // No pre-existing exception of the same type.  Chain it on the list.
 267   push_exception_state(ex_map);
 268 }
 269 
 270 //-----------------------add_exception_states_from-----------------------------
 271 void GraphKit::add_exception_states_from(JVMState* jvms) {
 272   SafePointNode* ex_map = jvms->map()->next_exception();
 273   if (ex_map != NULL) {
 274     jvms->map()->set_next_exception(NULL);
 275     for (SafePointNode* next_map; ex_map != NULL; ex_map = next_map) {
 276       next_map = ex_map->next_exception();
 277       ex_map->set_next_exception(NULL);
 278       add_exception_state(ex_map);
 279     }
 280   }
 281 }
 282 
 283 //-----------------------transfer_exceptions_into_jvms-------------------------
 284 JVMState* GraphKit::transfer_exceptions_into_jvms() {
 285   if (map() == NULL) {
 286     // We need a JVMS to carry the exceptions, but the map has gone away.
 287     // Create a scratch JVMS, cloned from any of the exception states...
 288     if (has_exceptions()) {
 289       _map = _exceptions;
 290       _map = clone_map();
 291       _map->set_next_exception(NULL);
 292       clear_saved_ex_oop(_map);
 293       debug_only(verify_map());
 294     } else {
 295       // ...or created from scratch
 296       JVMState* jvms = new (C) JVMState(_method, NULL);
 297       jvms->set_bci(_bci);
 298       jvms->set_sp(_sp);
 299       jvms->set_map(new SafePointNode(TypeFunc::Parms, jvms));
 300       set_jvms(jvms);
 301       for (uint i = 0; i < map()->req(); i++)  map()->init_req(i, top());
 302       set_all_memory(top());
 303       while (map()->req() < jvms->endoff())  map()->add_req(top());
 304     }
 305     // (This is a kludge, in case you didn't notice.)
 306     set_control(top());
 307   }
 308   JVMState* jvms = sync_jvms();
 309   assert(!jvms->map()->has_exceptions(), "no exceptions on this map yet");
 310   jvms->map()->set_next_exception(_exceptions);
 311   _exceptions = NULL;   // done with this set of exceptions
 312   return jvms;
 313 }
 314 
 315 static inline void add_n_reqs(Node* dstphi, Node* srcphi) {
 316   assert(is_hidden_merge(dstphi), "must be a special merge node");
 317   assert(is_hidden_merge(srcphi), "must be a special merge node");
 318   uint limit = srcphi->req();
 319   for (uint i = PhiNode::Input; i < limit; i++) {
 320     dstphi->add_req(srcphi->in(i));
 321   }
 322 }
 323 static inline void add_one_req(Node* dstphi, Node* src) {
 324   assert(is_hidden_merge(dstphi), "must be a special merge node");
 325   assert(!is_hidden_merge(src), "must not be a special merge node");
 326   dstphi->add_req(src);
 327 }
 328 
 329 //-----------------------combine_exception_states------------------------------
 330 // This helper function combines exception states by building phis on a
 331 // specially marked state-merging region.  These regions and phis are
 332 // untransformed, and can build up gradually.  The region is marked by
 333 // having a control input of its exception map, rather than NULL.  Such
 334 // regions do not appear except in this function, and in use_exception_state.
 335 void GraphKit::combine_exception_states(SafePointNode* ex_map, SafePointNode* phi_map) {
 336   if (failing())  return;  // dying anyway...
 337   JVMState* ex_jvms = ex_map->_jvms;
 338   assert(ex_jvms->same_calls_as(phi_map->_jvms), "consistent call chains");
 339   assert(ex_jvms->stkoff() == phi_map->_jvms->stkoff(), "matching locals");
 340   assert(ex_jvms->sp() == phi_map->_jvms->sp(), "matching stack sizes");
 341   assert(ex_jvms->monoff() == phi_map->_jvms->monoff(), "matching JVMS");
 342   assert(ex_jvms->scloff() == phi_map->_jvms->scloff(), "matching scalar replaced objects");
 343   assert(ex_map->req() == phi_map->req(), "matching maps");
 344   uint tos = ex_jvms->stkoff() + ex_jvms->sp();
 345   Node*         hidden_merge_mark = root();
 346   Node*         region  = phi_map->control();
 347   MergeMemNode* phi_mem = phi_map->merged_memory();
 348   MergeMemNode* ex_mem  = ex_map->merged_memory();
 349   if (region->in(0) != hidden_merge_mark) {
 350     // The control input is not (yet) a specially-marked region in phi_map.
 351     // Make it so, and build some phis.
 352     region = new RegionNode(2);
 353     _gvn.set_type(region, Type::CONTROL);
 354     region->set_req(0, hidden_merge_mark);  // marks an internal ex-state
 355     region->init_req(1, phi_map->control());
 356     phi_map->set_control(region);
 357     Node* io_phi = PhiNode::make(region, phi_map->i_o(), Type::ABIO);
 358     record_for_igvn(io_phi);
 359     _gvn.set_type(io_phi, Type::ABIO);
 360     phi_map->set_i_o(io_phi);
 361     for (MergeMemStream mms(phi_mem); mms.next_non_empty(); ) {
 362       Node* m = mms.memory();
 363       Node* m_phi = PhiNode::make(region, m, Type::MEMORY, mms.adr_type(C));
 364       record_for_igvn(m_phi);
 365       _gvn.set_type(m_phi, Type::MEMORY);
 366       mms.set_memory(m_phi);
 367     }
 368   }
 369 
 370   // Either or both of phi_map and ex_map might already be converted into phis.
 371   Node* ex_control = ex_map->control();
 372   // if there is special marking on ex_map also, we add multiple edges from src
 373   bool add_multiple = (ex_control->in(0) == hidden_merge_mark);
 374   // how wide was the destination phi_map, originally?
 375   uint orig_width = region->req();
 376 
 377   if (add_multiple) {
 378     add_n_reqs(region, ex_control);
 379     add_n_reqs(phi_map->i_o(), ex_map->i_o());
 380   } else {
 381     // ex_map has no merges, so we just add single edges everywhere
 382     add_one_req(region, ex_control);
 383     add_one_req(phi_map->i_o(), ex_map->i_o());
 384   }
 385   for (MergeMemStream mms(phi_mem, ex_mem); mms.next_non_empty2(); ) {
 386     if (mms.is_empty()) {
 387       // get a copy of the base memory, and patch some inputs into it
 388       const TypePtr* adr_type = mms.adr_type(C);
 389       Node* phi = mms.force_memory()->as_Phi()->slice_memory(adr_type);
 390       assert(phi->as_Phi()->region() == mms.base_memory()->in(0), "");
 391       mms.set_memory(phi);
 392       // Prepare to append interesting stuff onto the newly sliced phi:
 393       while (phi->req() > orig_width)  phi->del_req(phi->req()-1);
 394     }
 395     // Append stuff from ex_map:
 396     if (add_multiple) {
 397       add_n_reqs(mms.memory(), mms.memory2());
 398     } else {
 399       add_one_req(mms.memory(), mms.memory2());
 400     }
 401   }
 402   uint limit = ex_map->req();
 403   for (uint i = TypeFunc::Parms; i < limit; i++) {
 404     // Skip everything in the JVMS after tos.  (The ex_oop follows.)
 405     if (i == tos)  i = ex_jvms->monoff();
 406     Node* src = ex_map->in(i);
 407     Node* dst = phi_map->in(i);
 408     if (src != dst) {
 409       PhiNode* phi;
 410       if (dst->in(0) != region) {
 411         dst = phi = PhiNode::make(region, dst, _gvn.type(dst));
 412         record_for_igvn(phi);
 413         _gvn.set_type(phi, phi->type());
 414         phi_map->set_req(i, dst);
 415         // Prepare to append interesting stuff onto the new phi:
 416         while (dst->req() > orig_width)  dst->del_req(dst->req()-1);
 417       } else {
 418         assert(dst->is_Phi(), "nobody else uses a hidden region");
 419         phi = dst->as_Phi();
 420       }
 421       if (add_multiple && src->in(0) == ex_control) {
 422         // Both are phis.
 423         add_n_reqs(dst, src);
 424       } else {
 425         while (dst->req() < region->req())  add_one_req(dst, src);
 426       }
 427       const Type* srctype = _gvn.type(src);
 428       if (phi->type() != srctype) {
 429         const Type* dsttype = phi->type()->meet_speculative(srctype);
 430         if (phi->type() != dsttype) {
 431           phi->set_type(dsttype);
 432           _gvn.set_type(phi, dsttype);
 433         }
 434       }
 435     }
 436   }
 437   phi_map->merge_replaced_nodes_with(ex_map);
 438 }
 439 
 440 //--------------------------use_exception_state--------------------------------
 441 Node* GraphKit::use_exception_state(SafePointNode* phi_map) {
 442   if (failing()) { stop(); return top(); }
 443   Node* region = phi_map->control();
 444   Node* hidden_merge_mark = root();
 445   assert(phi_map->jvms()->map() == phi_map, "sanity: 1-1 relation");
 446   Node* ex_oop = clear_saved_ex_oop(phi_map);
 447   if (region->in(0) == hidden_merge_mark) {
 448     // Special marking for internal ex-states.  Process the phis now.
 449     region->set_req(0, region);  // now it's an ordinary region
 450     set_jvms(phi_map->jvms());   // ...so now we can use it as a map
 451     // Note: Setting the jvms also sets the bci and sp.
 452     set_control(_gvn.transform(region));
 453     uint tos = jvms()->stkoff() + sp();
 454     for (uint i = 1; i < tos; i++) {
 455       Node* x = phi_map->in(i);
 456       if (x->in(0) == region) {
 457         assert(x->is_Phi(), "expected a special phi");
 458         phi_map->set_req(i, _gvn.transform(x));
 459       }
 460     }
 461     for (MergeMemStream mms(merged_memory()); mms.next_non_empty(); ) {
 462       Node* x = mms.memory();
 463       if (x->in(0) == region) {
 464         assert(x->is_Phi(), "nobody else uses a hidden region");
 465         mms.set_memory(_gvn.transform(x));
 466       }
 467     }
 468     if (ex_oop->in(0) == region) {
 469       assert(ex_oop->is_Phi(), "expected a special phi");
 470       ex_oop = _gvn.transform(ex_oop);
 471     }
 472   } else {
 473     set_jvms(phi_map->jvms());
 474   }
 475 
 476   assert(!is_hidden_merge(phi_map->control()), "hidden ex. states cleared");
 477   assert(!is_hidden_merge(phi_map->i_o()), "hidden ex. states cleared");
 478   return ex_oop;
 479 }
 480 
 481 //---------------------------------java_bc-------------------------------------
 482 Bytecodes::Code GraphKit::java_bc() const {
 483   ciMethod* method = this->method();
 484   int       bci    = this->bci();
 485   if (method != NULL && bci != InvocationEntryBci)
 486     return method->java_code_at_bci(bci);
 487   else
 488     return Bytecodes::_illegal;
 489 }
 490 
 491 void GraphKit::uncommon_trap_if_should_post_on_exceptions(Deoptimization::DeoptReason reason,
 492                                                           bool must_throw) {
 493     // if the exception capability is set, then we will generate code
 494     // to check the JavaThread.should_post_on_exceptions flag to see
 495     // if we actually need to report exception events (for this
 496     // thread).  If we don't need to report exception events, we will
 497     // take the normal fast path provided by add_exception_events.  If
 498     // exception event reporting is enabled for this thread, we will
 499     // take the uncommon_trap in the BuildCutout below.
 500 
 501     // first must access the should_post_on_exceptions_flag in this thread's JavaThread
 502     Node* jthread = _gvn.transform(new ThreadLocalNode());
 503     Node* adr = basic_plus_adr(top(), jthread, in_bytes(JavaThread::should_post_on_exceptions_flag_offset()));
 504     Node* should_post_flag = make_load(control(), adr, TypeInt::INT, T_INT, Compile::AliasIdxRaw, MemNode::unordered);
 505 
 506     // Test the should_post_on_exceptions_flag vs. 0
 507     Node* chk = _gvn.transform( new CmpINode(should_post_flag, intcon(0)) );
 508     Node* tst = _gvn.transform( new BoolNode(chk, BoolTest::eq) );
 509 
 510     // Branch to slow_path if should_post_on_exceptions_flag was true
 511     { BuildCutout unless(this, tst, PROB_MAX);
 512       // Do not try anything fancy if we're notifying the VM on every throw.
 513       // Cf. case Bytecodes::_athrow in parse2.cpp.
 514       uncommon_trap(reason, Deoptimization::Action_none,
 515                     (ciKlass*)NULL, (char*)NULL, must_throw);
 516     }
 517 
 518 }
 519 
 520 //------------------------------builtin_throw----------------------------------
 521 void GraphKit::builtin_throw(Deoptimization::DeoptReason reason, Node* arg) {
 522   bool must_throw = true;
 523 
 524   if (env()->jvmti_can_post_on_exceptions()) {
 525     // check if we must post exception events, take uncommon trap if so
 526     uncommon_trap_if_should_post_on_exceptions(reason, must_throw);
 527     // here if should_post_on_exceptions is false
 528     // continue on with the normal codegen
 529   }
 530 
 531   // If this particular condition has not yet happened at this
 532   // bytecode, then use the uncommon trap mechanism, and allow for
 533   // a future recompilation if several traps occur here.
 534   // If the throw is hot, try to use a more complicated inline mechanism
 535   // which keeps execution inside the compiled code.
 536   bool treat_throw_as_hot = false;
 537   ciMethodData* md = method()->method_data();
 538 
 539   if (ProfileTraps) {
 540     if (too_many_traps(reason)) {
 541       treat_throw_as_hot = true;
 542     }
 543     // (If there is no MDO at all, assume it is early in
 544     // execution, and that any deopts are part of the
 545     // startup transient, and don't need to be remembered.)
 546 
 547     // Also, if there is a local exception handler, treat all throws
 548     // as hot if there has been at least one in this method.
 549     if (C->trap_count(reason) != 0
 550         && method()->method_data()->trap_count(reason) != 0
 551         && has_ex_handler()) {
 552         treat_throw_as_hot = true;
 553     }
 554   }
 555 
 556   // If this throw happens frequently, an uncommon trap might cause
 557   // a performance pothole.  If there is a local exception handler,
 558   // and if this particular bytecode appears to be deoptimizing often,
 559   // let us handle the throw inline, with a preconstructed instance.
 560   // Note:   If the deopt count has blown up, the uncommon trap
 561   // runtime is going to flush this nmethod, not matter what.
 562   if (treat_throw_as_hot
 563       && (!StackTraceInThrowable || OmitStackTraceInFastThrow)) {
 564     // If the throw is local, we use a pre-existing instance and
 565     // punt on the backtrace.  This would lead to a missing backtrace
 566     // (a repeat of 4292742) if the backtrace object is ever asked
 567     // for its backtrace.
 568     // Fixing this remaining case of 4292742 requires some flavor of
 569     // escape analysis.  Leave that for the future.
 570     ciInstance* ex_obj = NULL;
 571     switch (reason) {
 572     case Deoptimization::Reason_null_check:
 573       ex_obj = env()->NullPointerException_instance();
 574       break;
 575     case Deoptimization::Reason_div0_check:
 576       ex_obj = env()->ArithmeticException_instance();
 577       break;
 578     case Deoptimization::Reason_range_check:
 579       ex_obj = env()->ArrayIndexOutOfBoundsException_instance();
 580       break;
 581     case Deoptimization::Reason_class_check:
 582       if (java_bc() == Bytecodes::_aastore) {
 583         ex_obj = env()->ArrayStoreException_instance();
 584       } else {
 585         ex_obj = env()->ClassCastException_instance();
 586       }
 587       break;
 588     default:
 589       break;
 590     }
 591     if (failing()) { stop(); return; }  // exception allocation might fail
 592     if (ex_obj != NULL) {
 593       // Cheat with a preallocated exception object.
 594       if (C->log() != NULL)
 595         C->log()->elem("hot_throw preallocated='1' reason='%s'",
 596                        Deoptimization::trap_reason_name(reason));
 597       const TypeInstPtr* ex_con  = TypeInstPtr::make(ex_obj);
 598       Node*              ex_node = _gvn.transform(ConNode::make(ex_con));
 599 
 600       // Clear the detail message of the preallocated exception object.
 601       // Weblogic sometimes mutates the detail message of exceptions
 602       // using reflection.
 603       int offset = java_lang_Throwable::get_detailMessage_offset();
 604       const TypePtr* adr_typ = ex_con->add_offset(offset);
 605 
 606       Node *adr = basic_plus_adr(ex_node, ex_node, offset);
 607       const TypeOopPtr* val_type = TypeOopPtr::make_from_klass(env()->String_klass());
 608       Node *store = access_store_at(ex_node, adr, adr_typ, null(), val_type, T_OBJECT, IN_HEAP);
 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 enforcing certain bytecodes to reexecute if
 819 // deoptimization happens
 820 static bool should_reexecute_implied_by_bytecode(JVMState *jvms, bool is_anewarray) {
 821   ciMethod* cur_method = jvms->method();
 822   int       cur_bci   = jvms->bci();
 823   if (cur_method != NULL && cur_bci != InvocationEntryBci) {
 824     Bytecodes::Code code = cur_method->java_code_at_bci(cur_bci);
 825     return Interpreter::bytecode_should_reexecute(code) ||
 826            (is_anewarray && code == Bytecodes::_multianewarray);
 827     // Reexecute _multianewarray bytecode which was replaced with
 828     // sequence of [a]newarray. See Parse::do_multianewarray().
 829     //
 830     // Note: interpreter should not have it set since this optimization
 831     // is limited by dimensions and guarded by flag so in some cases
 832     // multianewarray() runtime calls will be generated and
 833     // the bytecode should not be reexecutes (stack will not be reset).
 834   } else
 835     return false;
 836 }
 837 
 838 // Helper function for adding JVMState and debug information to node
 839 void GraphKit::add_safepoint_edges(SafePointNode* call, bool must_throw) {
 840   // Add the safepoint edges to the call (or other safepoint).
 841 
 842   // Make sure dead locals are set to top.  This
 843   // should help register allocation time and cut down on the size
 844   // of the deoptimization information.
 845   assert(dead_locals_are_killed(), "garbage in debug info before safepoint");
 846 
 847   // Walk the inline list to fill in the correct set of JVMState's
 848   // Also fill in the associated edges for each JVMState.
 849 
 850   // If the bytecode needs to be reexecuted we need to put
 851   // the arguments back on the stack.
 852   const bool should_reexecute = jvms()->should_reexecute();
 853   JVMState* youngest_jvms = should_reexecute ? sync_jvms_for_reexecute() : sync_jvms();
 854 
 855   // NOTE: set_bci (called from sync_jvms) might reset the reexecute bit to
 856   // undefined if the bci is different.  This is normal for Parse but it
 857   // should not happen for LibraryCallKit because only one bci is processed.
 858   assert(!is_LibraryCallKit() || (jvms()->should_reexecute() == should_reexecute),
 859          "in LibraryCallKit the reexecute bit should not change");
 860 
 861   // If we are guaranteed to throw, we can prune everything but the
 862   // input to the current bytecode.
 863   bool can_prune_locals = false;
 864   uint stack_slots_not_pruned = 0;
 865   int inputs = 0, depth = 0;
 866   if (must_throw) {
 867     assert(method() == youngest_jvms->method(), "sanity");
 868     if (compute_stack_effects(inputs, depth)) {
 869       can_prune_locals = true;
 870       stack_slots_not_pruned = inputs;
 871     }
 872   }
 873 
 874   if (env()->should_retain_local_variables()) {
 875     // At any safepoint, this method can get breakpointed, which would
 876     // then require an immediate deoptimization.
 877     can_prune_locals = false;  // do not prune locals
 878     stack_slots_not_pruned = 0;
 879   }
 880 
 881   // do not scribble on the input jvms
 882   JVMState* out_jvms = youngest_jvms->clone_deep(C);
 883   call->set_jvms(out_jvms); // Start jvms list for call node
 884 
 885   // For a known set of bytecodes, the interpreter should reexecute them if
 886   // deoptimization happens. We set the reexecute state for them here
 887   if (out_jvms->is_reexecute_undefined() && //don't change if already specified
 888       should_reexecute_implied_by_bytecode(out_jvms, call->is_AllocateArray())) {
 889     out_jvms->set_should_reexecute(true); //NOTE: youngest_jvms not changed
 890   }
 891 
 892   // Presize the call:
 893   DEBUG_ONLY(uint non_debug_edges = call->req());
 894   call->add_req_batch(top(), youngest_jvms->debug_depth());
 895   assert(call->req() == non_debug_edges + youngest_jvms->debug_depth(), "");
 896 
 897   // Set up edges so that the call looks like this:
 898   //  Call [state:] ctl io mem fptr retadr
 899   //       [parms:] parm0 ... parmN
 900   //       [root:]  loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN
 901   //    [...mid:]   loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN [...]
 902   //       [young:] loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN
 903   // Note that caller debug info precedes callee debug info.
 904 
 905   // Fill pointer walks backwards from "young:" to "root:" in the diagram above:
 906   uint debug_ptr = call->req();
 907 
 908   // Loop over the map input edges associated with jvms, add them
 909   // to the call node, & reset all offsets to match call node array.
 910   for (JVMState* in_jvms = youngest_jvms; in_jvms != NULL; ) {
 911     uint debug_end   = debug_ptr;
 912     uint debug_start = debug_ptr - in_jvms->debug_size();
 913     debug_ptr = debug_start;  // back up the ptr
 914 
 915     uint p = debug_start;  // walks forward in [debug_start, debug_end)
 916     uint j, k, l;
 917     SafePointNode* in_map = in_jvms->map();
 918     out_jvms->set_map(call);
 919 
 920     if (can_prune_locals) {
 921       assert(in_jvms->method() == out_jvms->method(), "sanity");
 922       // If the current throw can reach an exception handler in this JVMS,
 923       // then we must keep everything live that can reach that handler.
 924       // As a quick and dirty approximation, we look for any handlers at all.
 925       if (in_jvms->method()->has_exception_handlers()) {
 926         can_prune_locals = false;
 927       }
 928     }
 929 
 930     // Add the Locals
 931     k = in_jvms->locoff();
 932     l = in_jvms->loc_size();
 933     out_jvms->set_locoff(p);
 934     if (!can_prune_locals) {
 935       for (j = 0; j < l; j++)
 936         call->set_req(p++, in_map->in(k+j));
 937     } else {
 938       p += l;  // already set to top above by add_req_batch
 939     }
 940 
 941     // Add the Expression Stack
 942     k = in_jvms->stkoff();
 943     l = in_jvms->sp();
 944     out_jvms->set_stkoff(p);
 945     if (!can_prune_locals) {
 946       for (j = 0; j < l; j++)
 947         call->set_req(p++, in_map->in(k+j));
 948     } else if (can_prune_locals && stack_slots_not_pruned != 0) {
 949       // Divide stack into {S0,...,S1}, where S0 is set to top.
 950       uint s1 = stack_slots_not_pruned;
 951       stack_slots_not_pruned = 0;  // for next iteration
 952       if (s1 > l)  s1 = l;
 953       uint s0 = l - s1;
 954       p += s0;  // skip the tops preinstalled by add_req_batch
 955       for (j = s0; j < l; j++)
 956         call->set_req(p++, in_map->in(k+j));
 957     } else {
 958       p += l;  // already set to top above by add_req_batch
 959     }
 960 
 961     // Add the Monitors
 962     k = in_jvms->monoff();
 963     l = in_jvms->mon_size();
 964     out_jvms->set_monoff(p);
 965     for (j = 0; j < l; j++)
 966       call->set_req(p++, in_map->in(k+j));
 967 
 968     // Copy any scalar object fields.
 969     k = in_jvms->scloff();
 970     l = in_jvms->scl_size();
 971     out_jvms->set_scloff(p);
 972     for (j = 0; j < l; j++)
 973       call->set_req(p++, in_map->in(k+j));
 974 
 975     // Finish the new jvms.
 976     out_jvms->set_endoff(p);
 977 
 978     assert(out_jvms->endoff()     == debug_end,             "fill ptr must match");
 979     assert(out_jvms->depth()      == in_jvms->depth(),      "depth must match");
 980     assert(out_jvms->loc_size()   == in_jvms->loc_size(),   "size must match");
 981     assert(out_jvms->mon_size()   == in_jvms->mon_size(),   "size must match");
 982     assert(out_jvms->scl_size()   == in_jvms->scl_size(),   "size must match");
 983     assert(out_jvms->debug_size() == in_jvms->debug_size(), "size must match");
 984 
 985     // Update the two tail pointers in parallel.
 986     out_jvms = out_jvms->caller();
 987     in_jvms  = in_jvms->caller();
 988   }
 989 
 990   assert(debug_ptr == non_debug_edges, "debug info must fit exactly");
 991 
 992   // Test the correctness of JVMState::debug_xxx accessors:
 993   assert(call->jvms()->debug_start() == non_debug_edges, "");
 994   assert(call->jvms()->debug_end()   == call->req(), "");
 995   assert(call->jvms()->debug_depth() == call->req() - non_debug_edges, "");
 996 }
 997 
 998 bool GraphKit::compute_stack_effects(int& inputs, int& depth) {
 999   Bytecodes::Code code = java_bc();
1000   if (code == Bytecodes::_wide) {
1001     code = method()->java_code_at_bci(bci() + 1);
1002   }
1003 
1004   BasicType rtype = T_ILLEGAL;
1005   int       rsize = 0;
1006 
1007   if (code != Bytecodes::_illegal) {
1008     depth = Bytecodes::depth(code); // checkcast=0, athrow=-1
1009     rtype = Bytecodes::result_type(code); // checkcast=P, athrow=V
1010     if (rtype < T_CONFLICT)
1011       rsize = type2size[rtype];
1012   }
1013 
1014   switch (code) {
1015   case Bytecodes::_illegal:
1016     return false;
1017 
1018   case Bytecodes::_ldc:
1019   case Bytecodes::_ldc_w:
1020   case Bytecodes::_ldc2_w:
1021     inputs = 0;
1022     break;
1023 
1024   case Bytecodes::_dup:         inputs = 1;  break;
1025   case Bytecodes::_dup_x1:      inputs = 2;  break;
1026   case Bytecodes::_dup_x2:      inputs = 3;  break;
1027   case Bytecodes::_dup2:        inputs = 2;  break;
1028   case Bytecodes::_dup2_x1:     inputs = 3;  break;
1029   case Bytecodes::_dup2_x2:     inputs = 4;  break;
1030   case Bytecodes::_swap:        inputs = 2;  break;
1031   case Bytecodes::_arraylength: inputs = 1;  break;
1032 
1033   case Bytecodes::_getstatic:
1034   case Bytecodes::_putstatic:
1035   case Bytecodes::_getfield:
1036   case Bytecodes::_putfield:
1037     {
1038       bool ignored_will_link;
1039       ciField* field = method()->get_field_at_bci(bci(), ignored_will_link);
1040       int      size  = field->type()->size();
1041       bool is_get = (depth >= 0), is_static = (depth & 1);
1042       inputs = (is_static ? 0 : 1);
1043       if (is_get) {
1044         depth = size - inputs;
1045       } else {
1046         inputs += size;        // putxxx pops the value from the stack
1047         depth = - inputs;
1048       }
1049     }
1050     break;
1051 
1052   case Bytecodes::_invokevirtual:
1053   case Bytecodes::_invokespecial:
1054   case Bytecodes::_invokestatic:
1055   case Bytecodes::_invokedynamic:
1056   case Bytecodes::_invokeinterface:
1057     {
1058       bool ignored_will_link;
1059       ciSignature* declared_signature = NULL;
1060       ciMethod* ignored_callee = method()->get_method_at_bci(bci(), ignored_will_link, &declared_signature);
1061       assert(declared_signature != NULL, "cannot be null");
1062       inputs   = declared_signature->arg_size_for_bc(code);
1063       int size = declared_signature->return_type()->size();
1064       depth = size - inputs;
1065     }
1066     break;
1067 
1068   case Bytecodes::_multianewarray:
1069     {
1070       ciBytecodeStream iter(method());
1071       iter.reset_to_bci(bci());
1072       iter.next();
1073       inputs = iter.get_dimensions();
1074       assert(rsize == 1, "");
1075       depth = rsize - inputs;
1076     }
1077     break;
1078 
1079   case Bytecodes::_ireturn:
1080   case Bytecodes::_lreturn:
1081   case Bytecodes::_freturn:
1082   case Bytecodes::_dreturn:
1083   case Bytecodes::_areturn:
1084     assert(rsize == -depth, "");
1085     inputs = rsize;
1086     break;
1087 
1088   case Bytecodes::_jsr:
1089   case Bytecodes::_jsr_w:
1090     inputs = 0;
1091     depth  = 1;                  // S.B. depth=1, not zero
1092     break;
1093 
1094   default:
1095     // bytecode produces a typed result
1096     inputs = rsize - depth;
1097     assert(inputs >= 0, "");
1098     break;
1099   }
1100 
1101 #ifdef ASSERT
1102   // spot check
1103   int outputs = depth + inputs;
1104   assert(outputs >= 0, "sanity");
1105   switch (code) {
1106   case Bytecodes::_checkcast: assert(inputs == 1 && outputs == 1, ""); break;
1107   case Bytecodes::_athrow:    assert(inputs == 1 && outputs == 0, ""); break;
1108   case Bytecodes::_aload_0:   assert(inputs == 0 && outputs == 1, ""); break;
1109   case Bytecodes::_return:    assert(inputs == 0 && outputs == 0, ""); break;
1110   case Bytecodes::_drem:      assert(inputs == 4 && outputs == 2, ""); break;
1111   default:                    break;
1112   }
1113 #endif //ASSERT
1114 
1115   return true;
1116 }
1117 
1118 
1119 
1120 //------------------------------basic_plus_adr---------------------------------
1121 Node* GraphKit::basic_plus_adr(Node* base, Node* ptr, Node* offset) {
1122   // short-circuit a common case
1123   if (offset == intcon(0))  return ptr;
1124   return _gvn.transform( new AddPNode(base, ptr, offset) );
1125 }
1126 
1127 Node* GraphKit::ConvI2L(Node* offset) {
1128   // short-circuit a common case
1129   jint offset_con = find_int_con(offset, Type::OffsetBot);
1130   if (offset_con != Type::OffsetBot) {
1131     return longcon((jlong) offset_con);
1132   }
1133   return _gvn.transform( new ConvI2LNode(offset));
1134 }
1135 
1136 Node* GraphKit::ConvI2UL(Node* offset) {
1137   juint offset_con = (juint) find_int_con(offset, Type::OffsetBot);
1138   if (offset_con != (juint) Type::OffsetBot) {
1139     return longcon((julong) offset_con);
1140   }
1141   Node* conv = _gvn.transform( new ConvI2LNode(offset));
1142   Node* mask = _gvn.transform(ConLNode::make((julong) max_juint));
1143   return _gvn.transform( new AndLNode(conv, mask) );
1144 }
1145 
1146 Node* GraphKit::ConvL2I(Node* offset) {
1147   // short-circuit a common case
1148   jlong offset_con = find_long_con(offset, (jlong)Type::OffsetBot);
1149   if (offset_con != (jlong)Type::OffsetBot) {
1150     return intcon((int) offset_con);
1151   }
1152   return _gvn.transform( new ConvL2INode(offset));
1153 }
1154 
1155 //-------------------------load_object_klass-----------------------------------
1156 Node* GraphKit::load_object_klass(Node* obj) {
1157   // Special-case a fresh allocation to avoid building nodes:
1158   Node* akls = AllocateNode::Ideal_klass(obj, &_gvn);
1159   if (akls != NULL)  return akls;
1160   Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes());
1161   return _gvn.transform(LoadKlassNode::make(_gvn, NULL, immutable_memory(), k_adr, TypeInstPtr::KLASS));
1162 }
1163 
1164 //-------------------------load_array_length-----------------------------------
1165 Node* GraphKit::load_array_length(Node* array) {
1166   // Special-case a fresh allocation to avoid building nodes:
1167   AllocateArrayNode* alloc = AllocateArrayNode::Ideal_array_allocation(array, &_gvn);
1168   Node *alen;
1169   if (alloc == NULL) {
1170     Node *r_adr = basic_plus_adr(array, arrayOopDesc::length_offset_in_bytes());
1171     alen = _gvn.transform( new LoadRangeNode(0, immutable_memory(), r_adr, TypeInt::POS));
1172   } else {
1173     alen = alloc->Ideal_length();
1174     Node* ccast = alloc->make_ideal_length(_gvn.type(array)->is_oopptr(), &_gvn);
1175     if (ccast != alen) {
1176       alen = _gvn.transform(ccast);
1177     }
1178   }
1179   return alen;
1180 }
1181 
1182 //------------------------------do_null_check----------------------------------
1183 // Helper function to do a NULL pointer check.  Returned value is
1184 // the incoming address with NULL casted away.  You are allowed to use the
1185 // not-null value only if you are control dependent on the test.
1186 #ifndef PRODUCT
1187 extern int explicit_null_checks_inserted,
1188            explicit_null_checks_elided;
1189 #endif
1190 Node* GraphKit::null_check_common(Node* value, BasicType type,
1191                                   // optional arguments for variations:
1192                                   bool assert_null,
1193                                   Node* *null_control,
1194                                   bool speculative) {
1195   assert(!assert_null || null_control == NULL, "not both at once");
1196   if (stopped())  return top();
1197   NOT_PRODUCT(explicit_null_checks_inserted++);
1198 
1199   // Construct NULL check
1200   Node *chk = NULL;
1201   switch(type) {
1202     case T_LONG   : chk = new CmpLNode(value, _gvn.zerocon(T_LONG)); break;
1203     case T_INT    : chk = new CmpINode(value, _gvn.intcon(0)); break;
1204     case T_ARRAY  : // fall through
1205       type = T_OBJECT;  // simplify further tests
1206     case T_OBJECT : {
1207       const Type *t = _gvn.type( value );
1208 
1209       const TypeOopPtr* tp = t->isa_oopptr();
1210       if (tp != NULL && tp->klass() != NULL && !tp->klass()->is_loaded()
1211           // Only for do_null_check, not any of its siblings:
1212           && !assert_null && null_control == NULL) {
1213         // Usually, any field access or invocation on an unloaded oop type
1214         // will simply fail to link, since the statically linked class is
1215         // likely also to be unloaded.  However, in -Xcomp mode, sometimes
1216         // the static class is loaded but the sharper oop type is not.
1217         // Rather than checking for this obscure case in lots of places,
1218         // we simply observe that a null check on an unloaded class
1219         // will always be followed by a nonsense operation, so we
1220         // can just issue the uncommon trap here.
1221         // Our access to the unloaded class will only be correct
1222         // after it has been loaded and initialized, which requires
1223         // a trip through the interpreter.
1224 #ifndef PRODUCT
1225         if (WizardMode) { tty->print("Null check of unloaded "); tp->klass()->print(); tty->cr(); }
1226 #endif
1227         uncommon_trap(Deoptimization::Reason_unloaded,
1228                       Deoptimization::Action_reinterpret,
1229                       tp->klass(), "!loaded");
1230         return top();
1231       }
1232 
1233       if (assert_null) {
1234         // See if the type is contained in NULL_PTR.
1235         // If so, then the value is already null.
1236         if (t->higher_equal(TypePtr::NULL_PTR)) {
1237           NOT_PRODUCT(explicit_null_checks_elided++);
1238           return value;           // Elided null assert quickly!
1239         }
1240       } else {
1241         // See if mixing in the NULL pointer changes type.
1242         // If so, then the NULL pointer was not allowed in the original
1243         // type.  In other words, "value" was not-null.
1244         if (t->meet(TypePtr::NULL_PTR) != t->remove_speculative()) {
1245           // same as: if (!TypePtr::NULL_PTR->higher_equal(t)) ...
1246           NOT_PRODUCT(explicit_null_checks_elided++);
1247           return value;           // Elided null check quickly!
1248         }
1249       }
1250       chk = new CmpPNode( value, null() );
1251       break;
1252     }
1253 
1254     default:
1255       fatal("unexpected type: %s", type2name(type));
1256   }
1257   assert(chk != NULL, "sanity check");
1258   chk = _gvn.transform(chk);
1259 
1260   BoolTest::mask btest = assert_null ? BoolTest::eq : BoolTest::ne;
1261   BoolNode *btst = new BoolNode( chk, btest);
1262   Node   *tst = _gvn.transform( btst );
1263 
1264   //-----------
1265   // if peephole optimizations occurred, a prior test existed.
1266   // If a prior test existed, maybe it dominates as we can avoid this test.
1267   if (tst != btst && type == T_OBJECT) {
1268     // At this point we want to scan up the CFG to see if we can
1269     // find an identical test (and so avoid this test altogether).
1270     Node *cfg = control();
1271     int depth = 0;
1272     while( depth < 16 ) {       // Limit search depth for speed
1273       if( cfg->Opcode() == Op_IfTrue &&
1274           cfg->in(0)->in(1) == tst ) {
1275         // Found prior test.  Use "cast_not_null" to construct an identical
1276         // CastPP (and hence hash to) as already exists for the prior test.
1277         // Return that casted value.
1278         if (assert_null) {
1279           replace_in_map(value, null());
1280           return null();  // do not issue the redundant test
1281         }
1282         Node *oldcontrol = control();
1283         set_control(cfg);
1284         Node *res = cast_not_null(value);
1285         set_control(oldcontrol);
1286         NOT_PRODUCT(explicit_null_checks_elided++);
1287         return res;
1288       }
1289       cfg = IfNode::up_one_dom(cfg, /*linear_only=*/ true);
1290       if (cfg == NULL)  break;  // Quit at region nodes
1291       depth++;
1292     }
1293   }
1294 
1295   //-----------
1296   // Branch to failure if null
1297   float ok_prob = PROB_MAX;  // a priori estimate:  nulls never happen
1298   Deoptimization::DeoptReason reason;
1299   if (assert_null) {
1300     reason = Deoptimization::reason_null_assert(speculative);
1301   } else if (type == T_OBJECT) {
1302     reason = Deoptimization::reason_null_check(speculative);
1303   } else {
1304     reason = Deoptimization::Reason_div0_check;
1305   }
1306   // %%% Since Reason_unhandled is not recorded on a per-bytecode basis,
1307   // ciMethodData::has_trap_at will return a conservative -1 if any
1308   // must-be-null assertion has failed.  This could cause performance
1309   // problems for a method after its first do_null_assert failure.
1310   // Consider using 'Reason_class_check' instead?
1311 
1312   // To cause an implicit null check, we set the not-null probability
1313   // to the maximum (PROB_MAX).  For an explicit check the probability
1314   // is set to a smaller value.
1315   if (null_control != NULL || too_many_traps(reason)) {
1316     // probability is less likely
1317     ok_prob =  PROB_LIKELY_MAG(3);
1318   } else if (!assert_null &&
1319              (ImplicitNullCheckThreshold > 0) &&
1320              method() != NULL &&
1321              (method()->method_data()->trap_count(reason)
1322               >= (uint)ImplicitNullCheckThreshold)) {
1323     ok_prob =  PROB_LIKELY_MAG(3);
1324   }
1325 
1326   if (null_control != NULL) {
1327     IfNode* iff = create_and_map_if(control(), tst, ok_prob, COUNT_UNKNOWN);
1328     Node* null_true = _gvn.transform( new IfFalseNode(iff));
1329     set_control(      _gvn.transform( new IfTrueNode(iff)));
1330 #ifndef PRODUCT
1331     if (null_true == top()) {
1332       explicit_null_checks_elided++;
1333     }
1334 #endif
1335     (*null_control) = null_true;
1336   } else {
1337     BuildCutout unless(this, tst, ok_prob);
1338     // Check for optimizer eliding test at parse time
1339     if (stopped()) {
1340       // Failure not possible; do not bother making uncommon trap.
1341       NOT_PRODUCT(explicit_null_checks_elided++);
1342     } else if (assert_null) {
1343       uncommon_trap(reason,
1344                     Deoptimization::Action_make_not_entrant,
1345                     NULL, "assert_null");
1346     } else {
1347       replace_in_map(value, zerocon(type));
1348       builtin_throw(reason);
1349     }
1350   }
1351 
1352   // Must throw exception, fall-thru not possible?
1353   if (stopped()) {
1354     return top();               // No result
1355   }
1356 
1357   if (assert_null) {
1358     // Cast obj to null on this path.
1359     replace_in_map(value, zerocon(type));
1360     return zerocon(type);
1361   }
1362 
1363   // Cast obj to not-null on this path, if there is no null_control.
1364   // (If there is a null_control, a non-null value may come back to haunt us.)
1365   if (type == T_OBJECT) {
1366     Node* cast = cast_not_null(value, false);
1367     if (null_control == NULL || (*null_control) == top())
1368       replace_in_map(value, cast);
1369     value = cast;
1370   }
1371 
1372   return value;
1373 }
1374 
1375 
1376 //------------------------------cast_not_null----------------------------------
1377 // Cast obj to not-null on this path
1378 Node* GraphKit::cast_not_null(Node* obj, bool do_replace_in_map) {
1379   const Type *t = _gvn.type(obj);
1380   const Type *t_not_null = t->join_speculative(TypePtr::NOTNULL);
1381   // Object is already not-null?
1382   if( t == t_not_null ) return obj;
1383 
1384   Node *cast = new CastPPNode(obj,t_not_null);
1385   cast->init_req(0, control());
1386   cast = _gvn.transform( cast );
1387 
1388   // Scan for instances of 'obj' in the current JVM mapping.
1389   // These instances are known to be not-null after the test.
1390   if (do_replace_in_map)
1391     replace_in_map(obj, cast);
1392 
1393   return cast;                  // Return casted value
1394 }
1395 
1396 // Sometimes in intrinsics, we implicitly know an object is not null
1397 // (there's no actual null check) so we can cast it to not null. In
1398 // the course of optimizations, the input to the cast can become null.
1399 // In that case that data path will die and we need the control path
1400 // to become dead as well to keep the graph consistent. So we have to
1401 // add a check for null for which one branch can't be taken. It uses
1402 // an Opaque4 node that will cause the check to be removed after loop
1403 // opts so the test goes away and the compiled code doesn't execute a
1404 // useless check.
1405 Node* GraphKit::must_be_not_null(Node* value, bool do_replace_in_map) {
1406   Node* chk = _gvn.transform(new CmpPNode(value, null()));
1407   Node *tst = _gvn.transform(new BoolNode(chk, BoolTest::ne));
1408   Node* opaq = _gvn.transform(new Opaque4Node(C, tst, intcon(1)));
1409   IfNode *iff = new IfNode(control(), opaq, PROB_MAX, COUNT_UNKNOWN);
1410   _gvn.set_type(iff, iff->Value(&_gvn));
1411   Node *if_f = _gvn.transform(new IfFalseNode(iff));
1412   Node *frame = _gvn.transform(new ParmNode(C->start(), TypeFunc::FramePtr));
1413   Node *halt = _gvn.transform(new HaltNode(if_f, frame));
1414   C->root()->add_req(halt);
1415   Node *if_t = _gvn.transform(new IfTrueNode(iff));
1416   set_control(if_t);
1417   return cast_not_null(value, do_replace_in_map);
1418 }
1419 
1420 
1421 //--------------------------replace_in_map-------------------------------------
1422 void GraphKit::replace_in_map(Node* old, Node* neww) {
1423   if (old == neww) {
1424     return;
1425   }
1426 
1427   map()->replace_edge(old, neww);
1428 
1429   // Note: This operation potentially replaces any edge
1430   // on the map.  This includes locals, stack, and monitors
1431   // of the current (innermost) JVM state.
1432 
1433   // don't let inconsistent types from profiling escape this
1434   // method
1435 
1436   const Type* told = _gvn.type(old);
1437   const Type* tnew = _gvn.type(neww);
1438 
1439   if (!tnew->higher_equal(told)) {
1440     return;
1441   }
1442 
1443   map()->record_replaced_node(old, neww);
1444 }
1445 
1446 
1447 //=============================================================================
1448 //--------------------------------memory---------------------------------------
1449 Node* GraphKit::memory(uint alias_idx) {
1450   MergeMemNode* mem = merged_memory();
1451   Node* p = mem->memory_at(alias_idx);
1452   _gvn.set_type(p, Type::MEMORY);  // must be mapped
1453   return p;
1454 }
1455 
1456 //-----------------------------reset_memory------------------------------------
1457 Node* GraphKit::reset_memory() {
1458   Node* mem = map()->memory();
1459   // do not use this node for any more parsing!
1460   debug_only( map()->set_memory((Node*)NULL) );
1461   return _gvn.transform( mem );
1462 }
1463 
1464 //------------------------------set_all_memory---------------------------------
1465 void GraphKit::set_all_memory(Node* newmem) {
1466   Node* mergemem = MergeMemNode::make(newmem);
1467   gvn().set_type_bottom(mergemem);
1468   map()->set_memory(mergemem);
1469 }
1470 
1471 //------------------------------set_all_memory_call----------------------------
1472 void GraphKit::set_all_memory_call(Node* call, bool separate_io_proj) {
1473   Node* newmem = _gvn.transform( new ProjNode(call, TypeFunc::Memory, separate_io_proj) );
1474   set_all_memory(newmem);
1475 }
1476 
1477 //=============================================================================
1478 //
1479 // parser factory methods for MemNodes
1480 //
1481 // These are layered on top of the factory methods in LoadNode and StoreNode,
1482 // and integrate with the parser's memory state and _gvn engine.
1483 //
1484 
1485 // factory methods in "int adr_idx"
1486 Node* GraphKit::make_load(Node* ctl, Node* adr, const Type* t, BasicType bt,
1487                           int adr_idx,
1488                           MemNode::MemOrd mo,
1489                           LoadNode::ControlDependency control_dependency,
1490                           bool require_atomic_access,
1491                           bool unaligned,
1492                           bool mismatched,
1493                           bool unsafe) {
1494   assert(adr_idx != Compile::AliasIdxTop, "use other make_load factory" );
1495   const TypePtr* adr_type = NULL; // debug-mode-only argument
1496   debug_only(adr_type = C->get_adr_type(adr_idx));
1497   Node* mem = memory(adr_idx);
1498   Node* ld;
1499   if (require_atomic_access && bt == T_LONG) {
1500     ld = LoadLNode::make_atomic(ctl, mem, adr, adr_type, t, mo, control_dependency, unaligned, mismatched, unsafe);
1501   } else if (require_atomic_access && bt == T_DOUBLE) {
1502     ld = LoadDNode::make_atomic(ctl, mem, adr, adr_type, t, mo, control_dependency, unaligned, mismatched, unsafe);
1503   } else {
1504     ld = LoadNode::make(_gvn, ctl, mem, adr, adr_type, t, bt, mo, control_dependency, unaligned, mismatched, unsafe);
1505   }
1506   ld = _gvn.transform(ld);
1507   if (((bt == T_OBJECT) && C->do_escape_analysis()) || C->eliminate_boxing()) {
1508     // Improve graph before escape analysis and boxing elimination.
1509     record_for_igvn(ld);
1510   }
1511   return ld;
1512 }
1513 
1514 Node* GraphKit::store_to_memory(Node* ctl, Node* adr, Node *val, BasicType bt,
1515                                 int adr_idx,
1516                                 MemNode::MemOrd mo,
1517                                 bool require_atomic_access,
1518                                 bool unaligned,
1519                                 bool mismatched,
1520                                 bool unsafe) {
1521   assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
1522   const TypePtr* adr_type = NULL;
1523   debug_only(adr_type = C->get_adr_type(adr_idx));
1524   Node *mem = memory(adr_idx);
1525   Node* st;
1526   if (require_atomic_access && bt == T_LONG) {
1527     st = StoreLNode::make_atomic(ctl, mem, adr, adr_type, val, mo);
1528   } else if (require_atomic_access && bt == T_DOUBLE) {
1529     st = StoreDNode::make_atomic(ctl, mem, adr, adr_type, val, mo);
1530   } else {
1531     st = StoreNode::make(_gvn, ctl, mem, adr, adr_type, val, bt, mo);
1532   }
1533   if (unaligned) {
1534     st->as_Store()->set_unaligned_access();
1535   }
1536   if (mismatched) {
1537     st->as_Store()->set_mismatched_access();
1538   }
1539   if (unsafe) {
1540     st->as_Store()->set_unsafe_access();
1541   }
1542   st = _gvn.transform(st);
1543   set_memory(st, adr_idx);
1544   // Back-to-back stores can only remove intermediate store with DU info
1545   // so push on worklist for optimizer.
1546   if (mem->req() > MemNode::Address && adr == mem->in(MemNode::Address))
1547     record_for_igvn(st);
1548 
1549   return st;
1550 }
1551 
1552 Node* GraphKit::access_store_at(Node* obj,
1553                                 Node* adr,
1554                                 const TypePtr* adr_type,
1555                                 Node* val,
1556                                 const Type* val_type,
1557                                 BasicType bt,
1558                                 DecoratorSet decorators) {
1559   // Transformation of a value which could be NULL pointer (CastPP #NULL)
1560   // could be delayed during Parse (for example, in adjust_map_after_if()).
1561   // Execute transformation here to avoid barrier generation in such case.
1562   if (_gvn.type(val) == TypePtr::NULL_PTR) {
1563     val = _gvn.makecon(TypePtr::NULL_PTR);
1564   }
1565 
1566   if (stopped()) {
1567     return top(); // Dead path ?
1568   }
1569 
1570   assert(val != NULL, "not dead path");
1571 
1572   C2AccessValuePtr addr(adr, adr_type);
1573   C2AccessValue value(val, val_type);
1574   C2ParseAccess access(this, decorators | C2_WRITE_ACCESS, bt, obj, addr);
1575   if (access.is_raw()) {
1576     return _barrier_set->BarrierSetC2::store_at(access, value);
1577   } else {
1578     return _barrier_set->store_at(access, value);
1579   }
1580 }
1581 
1582 Node* GraphKit::access_load_at(Node* obj,   // containing obj
1583                                Node* adr,   // actual adress to store val at
1584                                const TypePtr* adr_type,
1585                                const Type* val_type,
1586                                BasicType bt,
1587                                DecoratorSet decorators) {
1588   if (stopped()) {
1589     return top(); // Dead path ?
1590   }
1591 
1592   C2AccessValuePtr addr(adr, adr_type);
1593   C2ParseAccess access(this, decorators | C2_READ_ACCESS, bt, obj, addr);
1594   if (access.is_raw()) {
1595     return _barrier_set->BarrierSetC2::load_at(access, val_type);
1596   } else {
1597     return _barrier_set->load_at(access, val_type);
1598   }
1599 }
1600 
1601 Node* GraphKit::access_load(Node* adr,   // actual adress to load val at
1602                             const Type* val_type,
1603                             BasicType bt,
1604                             DecoratorSet decorators) {
1605   if (stopped()) {
1606     return top(); // Dead path ?
1607   }
1608 
1609   C2AccessValuePtr addr(adr, NULL);
1610   C2ParseAccess access(this, decorators | C2_READ_ACCESS, bt, NULL, addr);
1611   if (access.is_raw()) {
1612     return _barrier_set->BarrierSetC2::load_at(access, val_type);
1613   } else {
1614     return _barrier_set->load_at(access, val_type);
1615   }
1616 }
1617 
1618 Node* GraphKit::access_atomic_cmpxchg_val_at(Node* obj,
1619                                              Node* adr,
1620                                              const TypePtr* adr_type,
1621                                              int alias_idx,
1622                                              Node* expected_val,
1623                                              Node* new_val,
1624                                              const Type* value_type,
1625                                              BasicType bt,
1626                                              DecoratorSet decorators) {
1627   C2AccessValuePtr addr(adr, adr_type);
1628   C2AtomicParseAccess access(this, decorators | C2_READ_ACCESS | C2_WRITE_ACCESS,
1629                         bt, obj, addr, alias_idx);
1630   if (access.is_raw()) {
1631     return _barrier_set->BarrierSetC2::atomic_cmpxchg_val_at(access, expected_val, new_val, value_type);
1632   } else {
1633     return _barrier_set->atomic_cmpxchg_val_at(access, expected_val, new_val, value_type);
1634   }
1635 }
1636 
1637 Node* GraphKit::access_atomic_cmpxchg_bool_at(Node* obj,
1638                                               Node* adr,
1639                                               const TypePtr* adr_type,
1640                                               int alias_idx,
1641                                               Node* expected_val,
1642                                               Node* new_val,
1643                                               const Type* value_type,
1644                                               BasicType bt,
1645                                               DecoratorSet decorators) {
1646   C2AccessValuePtr addr(adr, adr_type);
1647   C2AtomicParseAccess access(this, decorators | C2_READ_ACCESS | C2_WRITE_ACCESS,
1648                         bt, obj, addr, alias_idx);
1649   if (access.is_raw()) {
1650     return _barrier_set->BarrierSetC2::atomic_cmpxchg_bool_at(access, expected_val, new_val, value_type);
1651   } else {
1652     return _barrier_set->atomic_cmpxchg_bool_at(access, expected_val, new_val, value_type);
1653   }
1654 }
1655 
1656 Node* GraphKit::access_atomic_xchg_at(Node* obj,
1657                                       Node* adr,
1658                                       const TypePtr* adr_type,
1659                                       int alias_idx,
1660                                       Node* new_val,
1661                                       const Type* value_type,
1662                                       BasicType bt,
1663                                       DecoratorSet decorators) {
1664   C2AccessValuePtr addr(adr, adr_type);
1665   C2AtomicParseAccess access(this, decorators | C2_READ_ACCESS | C2_WRITE_ACCESS,
1666                         bt, obj, addr, alias_idx);
1667   if (access.is_raw()) {
1668     return _barrier_set->BarrierSetC2::atomic_xchg_at(access, new_val, value_type);
1669   } else {
1670     return _barrier_set->atomic_xchg_at(access, new_val, value_type);
1671   }
1672 }
1673 
1674 Node* GraphKit::access_atomic_add_at(Node* obj,
1675                                      Node* adr,
1676                                      const TypePtr* adr_type,
1677                                      int alias_idx,
1678                                      Node* new_val,
1679                                      const Type* value_type,
1680                                      BasicType bt,
1681                                      DecoratorSet decorators) {
1682   C2AccessValuePtr addr(adr, adr_type);
1683   C2AtomicParseAccess access(this, decorators | C2_READ_ACCESS | C2_WRITE_ACCESS, bt, obj, addr, alias_idx);
1684   if (access.is_raw()) {
1685     return _barrier_set->BarrierSetC2::atomic_add_at(access, new_val, value_type);
1686   } else {
1687     return _barrier_set->atomic_add_at(access, new_val, value_type);
1688   }
1689 }
1690 
1691 void GraphKit::access_clone(Node* src, Node* dst, Node* size, bool is_array) {
1692   return _barrier_set->clone(this, src, dst, size, is_array);
1693 }
1694 
1695 Node* GraphKit::access_resolve(Node* n, DecoratorSet decorators) {
1696   // Use stronger ACCESS_WRITE|ACCESS_READ by default.
1697   if ((decorators & (ACCESS_READ | ACCESS_WRITE)) == 0) {
1698     decorators |= ACCESS_READ | ACCESS_WRITE;
1699   }
1700   return _barrier_set->resolve(this, n, decorators);
1701 }
1702 
1703 //-------------------------array_element_address-------------------------
1704 Node* GraphKit::array_element_address(Node* ary, Node* idx, BasicType elembt,
1705                                       const TypeInt* sizetype, Node* ctrl) {
1706   uint shift  = exact_log2(type2aelembytes(elembt));
1707   uint header = arrayOopDesc::base_offset_in_bytes(elembt);
1708 
1709   // short-circuit a common case (saves lots of confusing waste motion)
1710   jint idx_con = find_int_con(idx, -1);
1711   if (idx_con >= 0) {
1712     intptr_t offset = header + ((intptr_t)idx_con << shift);
1713     return basic_plus_adr(ary, offset);
1714   }
1715 
1716   // must be correct type for alignment purposes
1717   Node* base  = basic_plus_adr(ary, header);
1718   idx = Compile::conv_I2X_index(&_gvn, idx, sizetype, ctrl);
1719   Node* scale = _gvn.transform( new LShiftXNode(idx, intcon(shift)) );
1720   return basic_plus_adr(ary, base, scale);
1721 }
1722 
1723 //-------------------------load_array_element-------------------------
1724 Node* GraphKit::load_array_element(Node* ctl, Node* ary, Node* idx, const TypeAryPtr* arytype) {
1725   const Type* elemtype = arytype->elem();
1726   BasicType elembt = elemtype->array_element_basic_type();
1727   Node* adr = array_element_address(ary, idx, elembt, arytype->size());
1728   if (elembt == T_NARROWOOP) {
1729     elembt = T_OBJECT; // To satisfy switch in LoadNode::make()
1730   }
1731   Node* ld = make_load(ctl, adr, elemtype, elembt, arytype, MemNode::unordered);
1732   return ld;
1733 }
1734 
1735 //-------------------------set_arguments_for_java_call-------------------------
1736 // Arguments (pre-popped from the stack) are taken from the JVMS.
1737 void GraphKit::set_arguments_for_java_call(CallJavaNode* call) {
1738   // Add the call arguments:
1739   uint nargs = call->method()->arg_size();
1740   for (uint i = 0; i < nargs; i++) {
1741     Node* arg = argument(i);
1742     call->init_req(i + TypeFunc::Parms, arg);
1743   }
1744 }
1745 
1746 //---------------------------set_edges_for_java_call---------------------------
1747 // Connect a newly created call into the current JVMS.
1748 // A return value node (if any) is returned from set_edges_for_java_call.
1749 void GraphKit::set_edges_for_java_call(CallJavaNode* call, bool must_throw, bool separate_io_proj) {
1750 
1751   // Add the predefined inputs:
1752   call->init_req( TypeFunc::Control, control() );
1753   call->init_req( TypeFunc::I_O    , i_o() );
1754   call->init_req( TypeFunc::Memory , reset_memory() );
1755   call->init_req( TypeFunc::FramePtr, frameptr() );
1756   call->init_req( TypeFunc::ReturnAdr, top() );
1757 
1758   add_safepoint_edges(call, must_throw);
1759 
1760   Node* xcall = _gvn.transform(call);
1761 
1762   if (xcall == top()) {
1763     set_control(top());
1764     return;
1765   }
1766   assert(xcall == call, "call identity is stable");
1767 
1768   // Re-use the current map to produce the result.
1769 
1770   set_control(_gvn.transform(new ProjNode(call, TypeFunc::Control)));
1771   set_i_o(    _gvn.transform(new ProjNode(call, TypeFunc::I_O    , separate_io_proj)));
1772   set_all_memory_call(xcall, separate_io_proj);
1773 
1774   //return xcall;   // no need, caller already has it
1775 }
1776 
1777 Node* GraphKit::set_results_for_java_call(CallJavaNode* call, bool separate_io_proj, bool deoptimize) {
1778   if (stopped())  return top();  // maybe the call folded up?
1779 
1780   // Capture the return value, if any.
1781   Node* ret;
1782   if (call->method() == NULL ||
1783       call->method()->return_type()->basic_type() == T_VOID)
1784         ret = top();
1785   else  ret = _gvn.transform(new ProjNode(call, TypeFunc::Parms));
1786 
1787   // Note:  Since any out-of-line call can produce an exception,
1788   // we always insert an I_O projection from the call into the result.
1789 
1790   make_slow_call_ex(call, env()->Throwable_klass(), separate_io_proj, deoptimize);
1791 
1792   if (separate_io_proj) {
1793     // The caller requested separate projections be used by the fall
1794     // through and exceptional paths, so replace the projections for
1795     // the fall through path.
1796     set_i_o(_gvn.transform( new ProjNode(call, TypeFunc::I_O) ));
1797     set_all_memory(_gvn.transform( new ProjNode(call, TypeFunc::Memory) ));
1798   }
1799   return ret;
1800 }
1801 
1802 //--------------------set_predefined_input_for_runtime_call--------------------
1803 // Reading and setting the memory state is way conservative here.
1804 // The real problem is that I am not doing real Type analysis on memory,
1805 // so I cannot distinguish card mark stores from other stores.  Across a GC
1806 // point the Store Barrier and the card mark memory has to agree.  I cannot
1807 // have a card mark store and its barrier split across the GC point from
1808 // either above or below.  Here I get that to happen by reading ALL of memory.
1809 // A better answer would be to separate out card marks from other memory.
1810 // For now, return the input memory state, so that it can be reused
1811 // after the call, if this call has restricted memory effects.
1812 Node* GraphKit::set_predefined_input_for_runtime_call(SafePointNode* call, Node* narrow_mem) {
1813   // Set fixed predefined input arguments
1814   Node* memory = reset_memory();
1815   Node* m = narrow_mem == NULL ? memory : narrow_mem;
1816   call->init_req( TypeFunc::Control,   control()  );
1817   call->init_req( TypeFunc::I_O,       top()      ); // does no i/o
1818   call->init_req( TypeFunc::Memory,    m          ); // may gc ptrs
1819   call->init_req( TypeFunc::FramePtr,  frameptr() );
1820   call->init_req( TypeFunc::ReturnAdr, top()      );
1821   return memory;
1822 }
1823 
1824 //-------------------set_predefined_output_for_runtime_call--------------------
1825 // Set control and memory (not i_o) from the call.
1826 // If keep_mem is not NULL, use it for the output state,
1827 // except for the RawPtr output of the call, if hook_mem is TypeRawPtr::BOTTOM.
1828 // If hook_mem is NULL, this call produces no memory effects at all.
1829 // If hook_mem is a Java-visible memory slice (such as arraycopy operands),
1830 // then only that memory slice is taken from the call.
1831 // In the last case, we must put an appropriate memory barrier before
1832 // the call, so as to create the correct anti-dependencies on loads
1833 // preceding the call.
1834 void GraphKit::set_predefined_output_for_runtime_call(Node* call,
1835                                                       Node* keep_mem,
1836                                                       const TypePtr* hook_mem) {
1837   // no i/o
1838   set_control(_gvn.transform( new ProjNode(call,TypeFunc::Control) ));
1839   if (keep_mem) {
1840     // First clone the existing memory state
1841     set_all_memory(keep_mem);
1842     if (hook_mem != NULL) {
1843       // Make memory for the call
1844       Node* mem = _gvn.transform( new ProjNode(call, TypeFunc::Memory) );
1845       // Set the RawPtr memory state only.  This covers all the heap top/GC stuff
1846       // We also use hook_mem to extract specific effects from arraycopy stubs.
1847       set_memory(mem, hook_mem);
1848     }
1849     // ...else the call has NO memory effects.
1850 
1851     // Make sure the call advertises its memory effects precisely.
1852     // This lets us build accurate anti-dependences in gcm.cpp.
1853     assert(C->alias_type(call->adr_type()) == C->alias_type(hook_mem),
1854            "call node must be constructed correctly");
1855   } else {
1856     assert(hook_mem == NULL, "");
1857     // This is not a "slow path" call; all memory comes from the call.
1858     set_all_memory_call(call);
1859   }
1860 }
1861 
1862 // Keep track of MergeMems feeding into other MergeMems
1863 static void add_mergemem_users_to_worklist(Unique_Node_List& wl, Node* mem) {
1864   if (!mem->is_MergeMem()) {
1865     return;
1866   }
1867   for (SimpleDUIterator i(mem); i.has_next(); i.next()) {
1868     Node* use = i.get();
1869     if (use->is_MergeMem()) {
1870       wl.push(use);
1871     }
1872   }
1873 }
1874 
1875 // Replace the call with the current state of the kit.
1876 void GraphKit::replace_call(CallNode* call, Node* result, bool do_replaced_nodes) {
1877   JVMState* ejvms = NULL;
1878   if (has_exceptions()) {
1879     ejvms = transfer_exceptions_into_jvms();
1880   }
1881 
1882   ReplacedNodes replaced_nodes = map()->replaced_nodes();
1883   ReplacedNodes replaced_nodes_exception;
1884   Node* ex_ctl = top();
1885 
1886   SafePointNode* final_state = stop();
1887 
1888   // Find all the needed outputs of this call
1889   CallProjections callprojs;
1890   call->extract_projections(&callprojs, true);
1891 
1892   Unique_Node_List wl;
1893   Node* init_mem = call->in(TypeFunc::Memory);
1894   Node* final_mem = final_state->in(TypeFunc::Memory);
1895   Node* final_ctl = final_state->in(TypeFunc::Control);
1896   Node* final_io = final_state->in(TypeFunc::I_O);
1897 
1898   // Replace all the old call edges with the edges from the inlining result
1899   if (callprojs.fallthrough_catchproj != NULL) {
1900     C->gvn_replace_by(callprojs.fallthrough_catchproj, final_ctl);
1901   }
1902   if (callprojs.fallthrough_memproj != NULL) {
1903     if (final_mem->is_MergeMem()) {
1904       // Parser's exits MergeMem was not transformed but may be optimized
1905       final_mem = _gvn.transform(final_mem);
1906     }
1907     C->gvn_replace_by(callprojs.fallthrough_memproj,   final_mem);
1908     add_mergemem_users_to_worklist(wl, final_mem);
1909   }
1910   if (callprojs.fallthrough_ioproj != NULL) {
1911     C->gvn_replace_by(callprojs.fallthrough_ioproj,    final_io);
1912   }
1913 
1914   // Replace the result with the new result if it exists and is used
1915   if (callprojs.resproj != NULL && result != NULL) {
1916     C->gvn_replace_by(callprojs.resproj, result);
1917   }
1918 
1919   if (ejvms == NULL) {
1920     // No exception edges to simply kill off those paths
1921     if (callprojs.catchall_catchproj != NULL) {
1922       C->gvn_replace_by(callprojs.catchall_catchproj, C->top());
1923     }
1924     if (callprojs.catchall_memproj != NULL) {
1925       C->gvn_replace_by(callprojs.catchall_memproj,   C->top());
1926     }
1927     if (callprojs.catchall_ioproj != NULL) {
1928       C->gvn_replace_by(callprojs.catchall_ioproj,    C->top());
1929     }
1930     // Replace the old exception object with top
1931     if (callprojs.exobj != NULL) {
1932       C->gvn_replace_by(callprojs.exobj, C->top());
1933     }
1934   } else {
1935     GraphKit ekit(ejvms);
1936 
1937     // Load my combined exception state into the kit, with all phis transformed:
1938     SafePointNode* ex_map = ekit.combine_and_pop_all_exception_states();
1939     replaced_nodes_exception = ex_map->replaced_nodes();
1940 
1941     Node* ex_oop = ekit.use_exception_state(ex_map);
1942 
1943     if (callprojs.catchall_catchproj != NULL) {
1944       C->gvn_replace_by(callprojs.catchall_catchproj, ekit.control());
1945       ex_ctl = ekit.control();
1946     }
1947     if (callprojs.catchall_memproj != NULL) {
1948       Node* ex_mem = ekit.reset_memory();
1949       C->gvn_replace_by(callprojs.catchall_memproj,   ex_mem);
1950       add_mergemem_users_to_worklist(wl, ex_mem);
1951     }
1952     if (callprojs.catchall_ioproj != NULL) {
1953       C->gvn_replace_by(callprojs.catchall_ioproj,    ekit.i_o());
1954     }
1955 
1956     // Replace the old exception object with the newly created one
1957     if (callprojs.exobj != NULL) {
1958       C->gvn_replace_by(callprojs.exobj, ex_oop);
1959     }
1960   }
1961 
1962   // Disconnect the call from the graph
1963   call->disconnect_inputs(NULL, C);
1964   C->gvn_replace_by(call, C->top());
1965 
1966   // Clean up any MergeMems that feed other MergeMems since the
1967   // optimizer doesn't like that.
1968   while (wl.size() > 0) {
1969     _gvn.transform(wl.pop());
1970   }
1971 
1972   if (callprojs.fallthrough_catchproj != NULL && !final_ctl->is_top() && do_replaced_nodes) {
1973     replaced_nodes.apply(C, final_ctl);
1974   }
1975   if (!ex_ctl->is_top() && do_replaced_nodes) {
1976     replaced_nodes_exception.apply(C, ex_ctl);
1977   }
1978 }
1979 
1980 
1981 //------------------------------increment_counter------------------------------
1982 // for statistics: increment a VM counter by 1
1983 
1984 void GraphKit::increment_counter(address counter_addr) {
1985   Node* adr1 = makecon(TypeRawPtr::make(counter_addr));
1986   increment_counter(adr1);
1987 }
1988 
1989 void GraphKit::increment_counter(Node* counter_addr) {
1990   int adr_type = Compile::AliasIdxRaw;
1991   Node* ctrl = control();
1992   Node* cnt  = make_load(ctrl, counter_addr, TypeInt::INT, T_INT, adr_type, MemNode::unordered);
1993   Node* incr = _gvn.transform(new AddINode(cnt, _gvn.intcon(1)));
1994   store_to_memory(ctrl, counter_addr, incr, T_INT, adr_type, MemNode::unordered);
1995 }
1996 
1997 
1998 //------------------------------uncommon_trap----------------------------------
1999 // Bail out to the interpreter in mid-method.  Implemented by calling the
2000 // uncommon_trap blob.  This helper function inserts a runtime call with the
2001 // right debug info.
2002 void GraphKit::uncommon_trap(int trap_request,
2003                              ciKlass* klass, const char* comment,
2004                              bool must_throw,
2005                              bool keep_exact_action) {
2006   if (failing())  stop();
2007   if (stopped())  return; // trap reachable?
2008 
2009   // Note:  If ProfileTraps is true, and if a deopt. actually
2010   // occurs here, the runtime will make sure an MDO exists.  There is
2011   // no need to call method()->ensure_method_data() at this point.
2012 
2013   // Set the stack pointer to the right value for reexecution:
2014   set_sp(reexecute_sp());
2015 
2016 #ifdef ASSERT
2017   if (!must_throw) {
2018     // Make sure the stack has at least enough depth to execute
2019     // the current bytecode.
2020     int inputs, ignored_depth;
2021     if (compute_stack_effects(inputs, ignored_depth)) {
2022       assert(sp() >= inputs, "must have enough JVMS stack to execute %s: sp=%d, inputs=%d",
2023              Bytecodes::name(java_bc()), sp(), inputs);
2024     }
2025   }
2026 #endif
2027 
2028   Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(trap_request);
2029   Deoptimization::DeoptAction action = Deoptimization::trap_request_action(trap_request);
2030 
2031   switch (action) {
2032   case Deoptimization::Action_maybe_recompile:
2033   case Deoptimization::Action_reinterpret:
2034     // Temporary fix for 6529811 to allow virtual calls to be sure they
2035     // get the chance to go from mono->bi->mega
2036     if (!keep_exact_action &&
2037         Deoptimization::trap_request_index(trap_request) < 0 &&
2038         too_many_recompiles(reason)) {
2039       // This BCI is causing too many recompilations.
2040       if (C->log() != NULL) {
2041         C->log()->elem("observe that='trap_action_change' reason='%s' from='%s' to='none'",
2042                 Deoptimization::trap_reason_name(reason),
2043                 Deoptimization::trap_action_name(action));
2044       }
2045       action = Deoptimization::Action_none;
2046       trap_request = Deoptimization::make_trap_request(reason, action);
2047     } else {
2048       C->set_trap_can_recompile(true);
2049     }
2050     break;
2051   case Deoptimization::Action_make_not_entrant:
2052     C->set_trap_can_recompile(true);
2053     break;
2054   case Deoptimization::Action_none:
2055   case Deoptimization::Action_make_not_compilable:
2056     break;
2057   default:
2058 #ifdef ASSERT
2059     fatal("unknown action %d: %s", action, Deoptimization::trap_action_name(action));
2060 #endif
2061     break;
2062   }
2063 
2064   if (TraceOptoParse) {
2065     char buf[100];
2066     tty->print_cr("Uncommon trap %s at bci:%d",
2067                   Deoptimization::format_trap_request(buf, sizeof(buf),
2068                                                       trap_request), bci());
2069   }
2070 
2071   CompileLog* log = C->log();
2072   if (log != NULL) {
2073     int kid = (klass == NULL)? -1: log->identify(klass);
2074     log->begin_elem("uncommon_trap bci='%d'", bci());
2075     char buf[100];
2076     log->print(" %s", Deoptimization::format_trap_request(buf, sizeof(buf),
2077                                                           trap_request));
2078     if (kid >= 0)         log->print(" klass='%d'", kid);
2079     if (comment != NULL)  log->print(" comment='%s'", comment);
2080     log->end_elem();
2081   }
2082 
2083   // Make sure any guarding test views this path as very unlikely
2084   Node *i0 = control()->in(0);
2085   if (i0 != NULL && i0->is_If()) {        // Found a guarding if test?
2086     IfNode *iff = i0->as_If();
2087     float f = iff->_prob;   // Get prob
2088     if (control()->Opcode() == Op_IfTrue) {
2089       if (f > PROB_UNLIKELY_MAG(4))
2090         iff->_prob = PROB_MIN;
2091     } else {
2092       if (f < PROB_LIKELY_MAG(4))
2093         iff->_prob = PROB_MAX;
2094     }
2095   }
2096 
2097   // Clear out dead values from the debug info.
2098   kill_dead_locals();
2099 
2100   // Now insert the uncommon trap subroutine call
2101   address call_addr = SharedRuntime::uncommon_trap_blob()->entry_point();
2102   const TypePtr* no_memory_effects = NULL;
2103   // Pass the index of the class to be loaded
2104   Node* call = make_runtime_call(RC_NO_LEAF | RC_UNCOMMON |
2105                                  (must_throw ? RC_MUST_THROW : 0),
2106                                  OptoRuntime::uncommon_trap_Type(),
2107                                  call_addr, "uncommon_trap", no_memory_effects,
2108                                  intcon(trap_request));
2109   assert(call->as_CallStaticJava()->uncommon_trap_request() == trap_request,
2110          "must extract request correctly from the graph");
2111   assert(trap_request != 0, "zero value reserved by uncommon_trap_request");
2112 
2113   call->set_req(TypeFunc::ReturnAdr, returnadr());
2114   // The debug info is the only real input to this call.
2115 
2116   // Halt-and-catch fire here.  The above call should never return!
2117   HaltNode* halt = new HaltNode(control(), frameptr());
2118   _gvn.set_type_bottom(halt);
2119   root()->add_req(halt);
2120 
2121   stop_and_kill_map();
2122 }
2123 
2124 
2125 //--------------------------just_allocated_object------------------------------
2126 // Report the object that was just allocated.
2127 // It must be the case that there are no intervening safepoints.
2128 // We use this to determine if an object is so "fresh" that
2129 // it does not require card marks.
2130 Node* GraphKit::just_allocated_object(Node* current_control) {
2131   Node* ctrl = current_control;
2132   // Object::<init> is invoked after allocation, most of invoke nodes
2133   // will be reduced, but a region node is kept in parse time, we check
2134   // the pattern and skip the region node if it degraded to a copy.
2135   if (ctrl != NULL && ctrl->is_Region() && ctrl->req() == 2 &&
2136       ctrl->as_Region()->is_copy()) {
2137     ctrl = ctrl->as_Region()->is_copy();
2138   }
2139   if (C->recent_alloc_ctl() == ctrl) {
2140    return C->recent_alloc_obj();
2141   }
2142   return NULL;
2143 }
2144 
2145 
2146 void GraphKit::round_double_arguments(ciMethod* dest_method) {
2147   // (Note:  TypeFunc::make has a cache that makes this fast.)
2148   const TypeFunc* tf    = TypeFunc::make(dest_method);
2149   int             nargs = tf->domain()->cnt() - TypeFunc::Parms;
2150   for (int j = 0; j < nargs; j++) {
2151     const Type *targ = tf->domain()->field_at(j + TypeFunc::Parms);
2152     if( targ->basic_type() == T_DOUBLE ) {
2153       // If any parameters are doubles, they must be rounded before
2154       // the call, dstore_rounding does gvn.transform
2155       Node *arg = argument(j);
2156       arg = dstore_rounding(arg);
2157       set_argument(j, arg);
2158     }
2159   }
2160 }
2161 
2162 /**
2163  * Record profiling data exact_kls for Node n with the type system so
2164  * that it can propagate it (speculation)
2165  *
2166  * @param n          node that the type applies to
2167  * @param exact_kls  type from profiling
2168  * @param maybe_null did profiling see null?
2169  *
2170  * @return           node with improved type
2171  */
2172 Node* GraphKit::record_profile_for_speculation(Node* n, ciKlass* exact_kls, ProfilePtrKind ptr_kind) {
2173   const Type* current_type = _gvn.type(n);
2174   assert(UseTypeSpeculation, "type speculation must be on");
2175 
2176   const TypePtr* speculative = current_type->speculative();
2177 
2178   // Should the klass from the profile be recorded in the speculative type?
2179   if (current_type->would_improve_type(exact_kls, jvms()->depth())) {
2180     const TypeKlassPtr* tklass = TypeKlassPtr::make(exact_kls);
2181     const TypeOopPtr* xtype = tklass->as_instance_type();
2182     assert(xtype->klass_is_exact(), "Should be exact");
2183     // Any reason to believe n is not null (from this profiling or a previous one)?
2184     assert(ptr_kind != ProfileAlwaysNull, "impossible here");
2185     const TypePtr* ptr = (ptr_kind == ProfileMaybeNull && current_type->speculative_maybe_null()) ? TypePtr::BOTTOM : TypePtr::NOTNULL;
2186     // record the new speculative type's depth
2187     speculative = xtype->cast_to_ptr_type(ptr->ptr())->is_ptr();
2188     speculative = speculative->with_inline_depth(jvms()->depth());
2189   } else if (current_type->would_improve_ptr(ptr_kind)) {
2190     // Profiling report that null was never seen so we can change the
2191     // speculative type to non null ptr.
2192     if (ptr_kind == ProfileAlwaysNull) {
2193       speculative = TypePtr::NULL_PTR;
2194     } else {
2195       assert(ptr_kind == ProfileNeverNull, "nothing else is an improvement");
2196       const TypePtr* ptr = TypePtr::NOTNULL;
2197       if (speculative != NULL) {
2198         speculative = speculative->cast_to_ptr_type(ptr->ptr())->is_ptr();
2199       } else {
2200         speculative = ptr;
2201       }
2202     }
2203   }
2204 
2205   if (speculative != current_type->speculative()) {
2206     // Build a type with a speculative type (what we think we know
2207     // about the type but will need a guard when we use it)
2208     const TypeOopPtr* spec_type = TypeOopPtr::make(TypePtr::BotPTR, Type::OffsetBot, TypeOopPtr::InstanceBot, speculative);
2209     // We're changing the type, we need a new CheckCast node to carry
2210     // the new type. The new type depends on the control: what
2211     // profiling tells us is only valid from here as far as we can
2212     // tell.
2213     Node* cast = new CheckCastPPNode(control(), n, current_type->remove_speculative()->join_speculative(spec_type));
2214     cast = _gvn.transform(cast);
2215     replace_in_map(n, cast);
2216     n = cast;
2217   }
2218 
2219   return n;
2220 }
2221 
2222 /**
2223  * Record profiling data from receiver profiling at an invoke with the
2224  * type system so that it can propagate it (speculation)
2225  *
2226  * @param n  receiver node
2227  *
2228  * @return   node with improved type
2229  */
2230 Node* GraphKit::record_profiled_receiver_for_speculation(Node* n) {
2231   if (!UseTypeSpeculation) {
2232     return n;
2233   }
2234   ciKlass* exact_kls = profile_has_unique_klass();
2235   ProfilePtrKind ptr_kind = ProfileMaybeNull;
2236   if ((java_bc() == Bytecodes::_checkcast ||
2237        java_bc() == Bytecodes::_instanceof ||
2238        java_bc() == Bytecodes::_aastore) &&
2239       method()->method_data()->is_mature()) {
2240     ciProfileData* data = method()->method_data()->bci_to_data(bci());
2241     if (data != NULL) {
2242       if (!data->as_BitData()->null_seen()) {
2243         ptr_kind = ProfileNeverNull;
2244       } else {
2245         assert(data->is_ReceiverTypeData(), "bad profile data type");
2246         ciReceiverTypeData* call = (ciReceiverTypeData*)data->as_ReceiverTypeData();
2247         uint i = 0;
2248         for (; i < call->row_limit(); i++) {
2249           ciKlass* receiver = call->receiver(i);
2250           if (receiver != NULL) {
2251             break;
2252           }
2253         }
2254         ptr_kind = (i == call->row_limit()) ? ProfileAlwaysNull : ProfileMaybeNull;
2255       }
2256     }
2257   }
2258   return record_profile_for_speculation(n, exact_kls, ptr_kind);
2259 }
2260 
2261 /**
2262  * Record profiling data from argument profiling at an invoke with the
2263  * type system so that it can propagate it (speculation)
2264  *
2265  * @param dest_method  target method for the call
2266  * @param bc           what invoke bytecode is this?
2267  */
2268 void GraphKit::record_profiled_arguments_for_speculation(ciMethod* dest_method, Bytecodes::Code bc) {
2269   if (!UseTypeSpeculation) {
2270     return;
2271   }
2272   const TypeFunc* tf    = TypeFunc::make(dest_method);
2273   int             nargs = tf->domain()->cnt() - TypeFunc::Parms;
2274   int skip = Bytecodes::has_receiver(bc) ? 1 : 0;
2275   for (int j = skip, i = 0; j < nargs && i < TypeProfileArgsLimit; j++) {
2276     const Type *targ = tf->domain()->field_at(j + TypeFunc::Parms);
2277     if (targ->basic_type() == T_OBJECT || targ->basic_type() == T_ARRAY) {
2278       ProfilePtrKind ptr_kind = ProfileMaybeNull;
2279       ciKlass* better_type = NULL;
2280       if (method()->argument_profiled_type(bci(), i, better_type, ptr_kind)) {
2281         record_profile_for_speculation(argument(j), better_type, ptr_kind);
2282       }
2283       i++;
2284     }
2285   }
2286 }
2287 
2288 /**
2289  * Record profiling data from parameter profiling at an invoke with
2290  * the type system so that it can propagate it (speculation)
2291  */
2292 void GraphKit::record_profiled_parameters_for_speculation() {
2293   if (!UseTypeSpeculation) {
2294     return;
2295   }
2296   for (int i = 0, j = 0; i < method()->arg_size() ; i++) {
2297     if (_gvn.type(local(i))->isa_oopptr()) {
2298       ProfilePtrKind ptr_kind = ProfileMaybeNull;
2299       ciKlass* better_type = NULL;
2300       if (method()->parameter_profiled_type(j, better_type, ptr_kind)) {
2301         record_profile_for_speculation(local(i), better_type, ptr_kind);
2302       }
2303       j++;
2304     }
2305   }
2306 }
2307 
2308 /**
2309  * Record profiling data from return value profiling at an invoke with
2310  * the type system so that it can propagate it (speculation)
2311  */
2312 void GraphKit::record_profiled_return_for_speculation() {
2313   if (!UseTypeSpeculation) {
2314     return;
2315   }
2316   ProfilePtrKind ptr_kind = ProfileMaybeNull;
2317   ciKlass* better_type = NULL;
2318   if (method()->return_profiled_type(bci(), better_type, ptr_kind)) {
2319     // If profiling reports a single type for the return value,
2320     // feed it to the type system so it can propagate it as a
2321     // speculative type
2322     record_profile_for_speculation(stack(sp()-1), better_type, ptr_kind);
2323   }
2324 }
2325 
2326 void GraphKit::round_double_result(ciMethod* dest_method) {
2327   // A non-strict method may return a double value which has an extended
2328   // exponent, but this must not be visible in a caller which is 'strict'
2329   // If a strict caller invokes a non-strict callee, round a double result
2330 
2331   BasicType result_type = dest_method->return_type()->basic_type();
2332   assert( method() != NULL, "must have caller context");
2333   if( result_type == T_DOUBLE && method()->is_strict() && !dest_method->is_strict() ) {
2334     // Destination method's return value is on top of stack
2335     // dstore_rounding() does gvn.transform
2336     Node *result = pop_pair();
2337     result = dstore_rounding(result);
2338     push_pair(result);
2339   }
2340 }
2341 
2342 // rounding for strict float precision conformance
2343 Node* GraphKit::precision_rounding(Node* n) {
2344   return UseStrictFP && _method->flags().is_strict()
2345     && UseSSE == 0 && Matcher::strict_fp_requires_explicit_rounding
2346     ? _gvn.transform( new RoundFloatNode(0, n) )
2347     : n;
2348 }
2349 
2350 // rounding for strict double precision conformance
2351 Node* GraphKit::dprecision_rounding(Node *n) {
2352   return UseStrictFP && _method->flags().is_strict()
2353     && UseSSE <= 1 && Matcher::strict_fp_requires_explicit_rounding
2354     ? _gvn.transform( new RoundDoubleNode(0, n) )
2355     : n;
2356 }
2357 
2358 // rounding for non-strict double stores
2359 Node* GraphKit::dstore_rounding(Node* n) {
2360   return Matcher::strict_fp_requires_explicit_rounding
2361     && UseSSE <= 1
2362     ? _gvn.transform( new RoundDoubleNode(0, n) )
2363     : n;
2364 }
2365 
2366 //=============================================================================
2367 // Generate a fast path/slow path idiom.  Graph looks like:
2368 // [foo] indicates that 'foo' is a parameter
2369 //
2370 //              [in]     NULL
2371 //                 \    /
2372 //                  CmpP
2373 //                  Bool ne
2374 //                   If
2375 //                  /  \
2376 //              True    False-<2>
2377 //              / |
2378 //             /  cast_not_null
2379 //           Load  |    |   ^
2380 //        [fast_test]   |   |
2381 // gvn to   opt_test    |   |
2382 //          /    \      |  <1>
2383 //      True     False  |
2384 //        |         \\  |
2385 //   [slow_call]     \[fast_result]
2386 //    Ctl   Val       \      \
2387 //     |               \      \
2388 //    Catch       <1>   \      \
2389 //   /    \        ^     \      \
2390 //  Ex    No_Ex    |      \      \
2391 //  |       \   \  |       \ <2>  \
2392 //  ...      \  [slow_res] |  |    \   [null_result]
2393 //            \         \--+--+---  |  |
2394 //             \           | /    \ | /
2395 //              --------Region     Phi
2396 //
2397 //=============================================================================
2398 // Code is structured as a series of driver functions all called 'do_XXX' that
2399 // call a set of helper functions.  Helper functions first, then drivers.
2400 
2401 //------------------------------null_check_oop---------------------------------
2402 // Null check oop.  Set null-path control into Region in slot 3.
2403 // Make a cast-not-nullness use the other not-null control.  Return cast.
2404 Node* GraphKit::null_check_oop(Node* value, Node* *null_control,
2405                                bool never_see_null,
2406                                bool safe_for_replace,
2407                                bool speculative) {
2408   // Initial NULL check taken path
2409   (*null_control) = top();
2410   Node* cast = null_check_common(value, T_OBJECT, false, null_control, speculative);
2411 
2412   // Generate uncommon_trap:
2413   if (never_see_null && (*null_control) != top()) {
2414     // If we see an unexpected null at a check-cast we record it and force a
2415     // recompile; the offending check-cast will be compiled to handle NULLs.
2416     // If we see more than one offending BCI, then all checkcasts in the
2417     // method will be compiled to handle NULLs.
2418     PreserveJVMState pjvms(this);
2419     set_control(*null_control);
2420     replace_in_map(value, null());
2421     Deoptimization::DeoptReason reason = Deoptimization::reason_null_check(speculative);
2422     uncommon_trap(reason,
2423                   Deoptimization::Action_make_not_entrant);
2424     (*null_control) = top();    // NULL path is dead
2425   }
2426   if ((*null_control) == top() && safe_for_replace) {
2427     replace_in_map(value, cast);
2428   }
2429 
2430   // Cast away null-ness on the result
2431   return cast;
2432 }
2433 
2434 //------------------------------opt_iff----------------------------------------
2435 // Optimize the fast-check IfNode.  Set the fast-path region slot 2.
2436 // Return slow-path control.
2437 Node* GraphKit::opt_iff(Node* region, Node* iff) {
2438   IfNode *opt_iff = _gvn.transform(iff)->as_If();
2439 
2440   // Fast path taken; set region slot 2
2441   Node *fast_taken = _gvn.transform( new IfFalseNode(opt_iff) );
2442   region->init_req(2,fast_taken); // Capture fast-control
2443 
2444   // Fast path not-taken, i.e. slow path
2445   Node *slow_taken = _gvn.transform( new IfTrueNode(opt_iff) );
2446   return slow_taken;
2447 }
2448 
2449 //-----------------------------make_runtime_call-------------------------------
2450 Node* GraphKit::make_runtime_call(int flags,
2451                                   const TypeFunc* call_type, address call_addr,
2452                                   const char* call_name,
2453                                   const TypePtr* adr_type,
2454                                   // The following parms are all optional.
2455                                   // The first NULL ends the list.
2456                                   Node* parm0, Node* parm1,
2457                                   Node* parm2, Node* parm3,
2458                                   Node* parm4, Node* parm5,
2459                                   Node* parm6, Node* parm7) {
2460   assert(call_addr != NULL, "must not call NULL targets");
2461 
2462   // Slow-path call
2463   bool is_leaf = !(flags & RC_NO_LEAF);
2464   bool has_io  = (!is_leaf && !(flags & RC_NO_IO));
2465   if (call_name == NULL) {
2466     assert(!is_leaf, "must supply name for leaf");
2467     call_name = OptoRuntime::stub_name(call_addr);
2468   }
2469   CallNode* call;
2470   if (!is_leaf) {
2471     call = new CallStaticJavaNode(call_type, call_addr, call_name,
2472                                            bci(), adr_type);
2473   } else if (flags & RC_NO_FP) {
2474     call = new CallLeafNoFPNode(call_type, call_addr, call_name, adr_type);
2475   } else {
2476     call = new CallLeafNode(call_type, call_addr, call_name, adr_type);
2477   }
2478 
2479   // The following is similar to set_edges_for_java_call,
2480   // except that the memory effects of the call are restricted to AliasIdxRaw.
2481 
2482   // Slow path call has no side-effects, uses few values
2483   bool wide_in  = !(flags & RC_NARROW_MEM);
2484   bool wide_out = (C->get_alias_index(adr_type) == Compile::AliasIdxBot);
2485 
2486   Node* prev_mem = NULL;
2487   if (wide_in) {
2488     prev_mem = set_predefined_input_for_runtime_call(call);
2489   } else {
2490     assert(!wide_out, "narrow in => narrow out");
2491     Node* narrow_mem = memory(adr_type);
2492     prev_mem = set_predefined_input_for_runtime_call(call, narrow_mem);
2493   }
2494 
2495   // Hook each parm in order.  Stop looking at the first NULL.
2496   if (parm0 != NULL) { call->init_req(TypeFunc::Parms+0, parm0);
2497   if (parm1 != NULL) { call->init_req(TypeFunc::Parms+1, parm1);
2498   if (parm2 != NULL) { call->init_req(TypeFunc::Parms+2, parm2);
2499   if (parm3 != NULL) { call->init_req(TypeFunc::Parms+3, parm3);
2500   if (parm4 != NULL) { call->init_req(TypeFunc::Parms+4, parm4);
2501   if (parm5 != NULL) { call->init_req(TypeFunc::Parms+5, parm5);
2502   if (parm6 != NULL) { call->init_req(TypeFunc::Parms+6, parm6);
2503   if (parm7 != NULL) { call->init_req(TypeFunc::Parms+7, parm7);
2504     /* close each nested if ===> */  } } } } } } } }
2505   assert(call->in(call->req()-1) != NULL, "must initialize all parms");
2506 
2507   if (!is_leaf) {
2508     // Non-leaves can block and take safepoints:
2509     add_safepoint_edges(call, ((flags & RC_MUST_THROW) != 0));
2510   }
2511   // Non-leaves can throw exceptions:
2512   if (has_io) {
2513     call->set_req(TypeFunc::I_O, i_o());
2514   }
2515 
2516   if (flags & RC_UNCOMMON) {
2517     // Set the count to a tiny probability.  Cf. Estimate_Block_Frequency.
2518     // (An "if" probability corresponds roughly to an unconditional count.
2519     // Sort of.)
2520     call->set_cnt(PROB_UNLIKELY_MAG(4));
2521   }
2522 
2523   Node* c = _gvn.transform(call);
2524   assert(c == call, "cannot disappear");
2525 
2526   if (wide_out) {
2527     // Slow path call has full side-effects.
2528     set_predefined_output_for_runtime_call(call);
2529   } else {
2530     // Slow path call has few side-effects, and/or sets few values.
2531     set_predefined_output_for_runtime_call(call, prev_mem, adr_type);
2532   }
2533 
2534   if (has_io) {
2535     set_i_o(_gvn.transform(new ProjNode(call, TypeFunc::I_O)));
2536   }
2537   return call;
2538 
2539 }
2540 
2541 //------------------------------merge_memory-----------------------------------
2542 // Merge memory from one path into the current memory state.
2543 void GraphKit::merge_memory(Node* new_mem, Node* region, int new_path) {
2544   for (MergeMemStream mms(merged_memory(), new_mem->as_MergeMem()); mms.next_non_empty2(); ) {
2545     Node* old_slice = mms.force_memory();
2546     Node* new_slice = mms.memory2();
2547     if (old_slice != new_slice) {
2548       PhiNode* phi;
2549       if (old_slice->is_Phi() && old_slice->as_Phi()->region() == region) {
2550         if (mms.is_empty()) {
2551           // clone base memory Phi's inputs for this memory slice
2552           assert(old_slice == mms.base_memory(), "sanity");
2553           phi = PhiNode::make(region, NULL, Type::MEMORY, mms.adr_type(C));
2554           _gvn.set_type(phi, Type::MEMORY);
2555           for (uint i = 1; i < phi->req(); i++) {
2556             phi->init_req(i, old_slice->in(i));
2557           }
2558         } else {
2559           phi = old_slice->as_Phi(); // Phi was generated already
2560         }
2561       } else {
2562         phi = PhiNode::make(region, old_slice, Type::MEMORY, mms.adr_type(C));
2563         _gvn.set_type(phi, Type::MEMORY);
2564       }
2565       phi->set_req(new_path, new_slice);
2566       mms.set_memory(phi);
2567     }
2568   }
2569 }
2570 
2571 //------------------------------make_slow_call_ex------------------------------
2572 // Make the exception handler hookups for the slow call
2573 void GraphKit::make_slow_call_ex(Node* call, ciInstanceKlass* ex_klass, bool separate_io_proj, bool deoptimize) {
2574   if (stopped())  return;
2575 
2576   // Make a catch node with just two handlers:  fall-through and catch-all
2577   Node* i_o  = _gvn.transform( new ProjNode(call, TypeFunc::I_O, separate_io_proj) );
2578   Node* catc = _gvn.transform( new CatchNode(control(), i_o, 2) );
2579   Node* norm = _gvn.transform( new CatchProjNode(catc, CatchProjNode::fall_through_index, CatchProjNode::no_handler_bci) );
2580   Node* excp = _gvn.transform( new CatchProjNode(catc, CatchProjNode::catch_all_index,    CatchProjNode::no_handler_bci) );
2581 
2582   { PreserveJVMState pjvms(this);
2583     set_control(excp);
2584     set_i_o(i_o);
2585 
2586     if (excp != top()) {
2587       if (deoptimize) {
2588         // Deoptimize if an exception is caught. Don't construct exception state in this case.
2589         uncommon_trap(Deoptimization::Reason_unhandled,
2590                       Deoptimization::Action_none);
2591       } else {
2592         // Create an exception state also.
2593         // Use an exact type if the caller has a specific exception.
2594         const Type* ex_type = TypeOopPtr::make_from_klass_unique(ex_klass)->cast_to_ptr_type(TypePtr::NotNull);
2595         Node*       ex_oop  = new CreateExNode(ex_type, control(), i_o);
2596         add_exception_state(make_exception_state(_gvn.transform(ex_oop)));
2597       }
2598     }
2599   }
2600 
2601   // Get the no-exception control from the CatchNode.
2602   set_control(norm);
2603 }
2604 
2605 static IfNode* gen_subtype_check_compare(Node* ctrl, Node* in1, Node* in2, BoolTest::mask test, float p, PhaseGVN* gvn, BasicType bt) {
2606   Node* cmp = NULL;
2607   switch(bt) {
2608   case T_INT: cmp = new CmpINode(in1, in2); break;
2609   case T_ADDRESS: cmp = new CmpPNode(in1, in2); break;
2610   default: fatal("unexpected comparison type %s", type2name(bt));
2611   }
2612   gvn->transform(cmp);
2613   Node* bol = gvn->transform(new BoolNode(cmp, test));
2614   IfNode* iff = new IfNode(ctrl, bol, p, COUNT_UNKNOWN);
2615   gvn->transform(iff);
2616   if (!bol->is_Con()) gvn->record_for_igvn(iff);
2617   return iff;
2618 }
2619 
2620 
2621 //-------------------------------gen_subtype_check-----------------------------
2622 // Generate a subtyping check.  Takes as input the subtype and supertype.
2623 // Returns 2 values: sets the default control() to the true path and returns
2624 // the false path.  Only reads invariant memory; sets no (visible) memory.
2625 // The PartialSubtypeCheckNode sets the hidden 1-word cache in the encoding
2626 // but that's not exposed to the optimizer.  This call also doesn't take in an
2627 // Object; if you wish to check an Object you need to load the Object's class
2628 // prior to coming here.
2629 Node* Phase::gen_subtype_check(Node* subklass, Node* superklass, Node** ctrl, MergeMemNode* mem, PhaseGVN* gvn) {
2630   Compile* C = gvn->C;
2631 
2632   if ((*ctrl)->is_top()) {
2633     return C->top();
2634   }
2635 
2636   // Fast check for identical types, perhaps identical constants.
2637   // The types can even be identical non-constants, in cases
2638   // involving Array.newInstance, Object.clone, etc.
2639   if (subklass == superklass)
2640     return C->top();             // false path is dead; no test needed.
2641 
2642   if (gvn->type(superklass)->singleton()) {
2643     ciKlass* superk = gvn->type(superklass)->is_klassptr()->klass();
2644     ciKlass* subk   = gvn->type(subklass)->is_klassptr()->klass();
2645 
2646     // In the common case of an exact superklass, try to fold up the
2647     // test before generating code.  You may ask, why not just generate
2648     // the code and then let it fold up?  The answer is that the generated
2649     // code will necessarily include null checks, which do not always
2650     // completely fold away.  If they are also needless, then they turn
2651     // into a performance loss.  Example:
2652     //    Foo[] fa = blah(); Foo x = fa[0]; fa[1] = x;
2653     // Here, the type of 'fa' is often exact, so the store check
2654     // of fa[1]=x will fold up, without testing the nullness of x.
2655     switch (C->static_subtype_check(superk, subk)) {
2656     case Compile::SSC_always_false:
2657       {
2658         Node* always_fail = *ctrl;
2659         *ctrl = gvn->C->top();
2660         return always_fail;
2661       }
2662     case Compile::SSC_always_true:
2663       return C->top();
2664     case Compile::SSC_easy_test:
2665       {
2666         // Just do a direct pointer compare and be done.
2667         IfNode* iff = gen_subtype_check_compare(*ctrl, subklass, superklass, BoolTest::eq, PROB_STATIC_FREQUENT, gvn, T_ADDRESS);
2668         *ctrl = gvn->transform(new IfTrueNode(iff));
2669         return gvn->transform(new IfFalseNode(iff));
2670       }
2671     case Compile::SSC_full_test:
2672       break;
2673     default:
2674       ShouldNotReachHere();
2675     }
2676   }
2677 
2678   // %%% Possible further optimization:  Even if the superklass is not exact,
2679   // if the subklass is the unique subtype of the superklass, the check
2680   // will always succeed.  We could leave a dependency behind to ensure this.
2681 
2682   // First load the super-klass's check-offset
2683   Node *p1 = gvn->transform(new AddPNode(superklass, superklass, gvn->MakeConX(in_bytes(Klass::super_check_offset_offset()))));
2684   Node* m = mem->memory_at(C->get_alias_index(gvn->type(p1)->is_ptr()));
2685   Node *chk_off = gvn->transform(new LoadINode(NULL, m, p1, gvn->type(p1)->is_ptr(), TypeInt::INT, MemNode::unordered));
2686   int cacheoff_con = in_bytes(Klass::secondary_super_cache_offset());
2687   bool might_be_cache = (gvn->find_int_con(chk_off, cacheoff_con) == cacheoff_con);
2688 
2689   // Load from the sub-klass's super-class display list, or a 1-word cache of
2690   // the secondary superclass list, or a failing value with a sentinel offset
2691   // if the super-klass is an interface or exceptionally deep in the Java
2692   // hierarchy and we have to scan the secondary superclass list the hard way.
2693   // Worst-case type is a little odd: NULL is allowed as a result (usually
2694   // klass loads can never produce a NULL).
2695   Node *chk_off_X = chk_off;
2696 #ifdef _LP64
2697   chk_off_X = gvn->transform(new ConvI2LNode(chk_off_X));
2698 #endif
2699   Node *p2 = gvn->transform(new AddPNode(subklass,subklass,chk_off_X));
2700   // For some types like interfaces the following loadKlass is from a 1-word
2701   // cache which is mutable so can't use immutable memory.  Other
2702   // types load from the super-class display table which is immutable.
2703   m = mem->memory_at(C->get_alias_index(gvn->type(p2)->is_ptr()));
2704   Node *kmem = might_be_cache ? m : C->immutable_memory();
2705   Node *nkls = gvn->transform(LoadKlassNode::make(*gvn, NULL, kmem, p2, gvn->type(p2)->is_ptr(), TypeKlassPtr::OBJECT_OR_NULL));
2706 
2707   // Compile speed common case: ARE a subtype and we canNOT fail
2708   if( superklass == nkls )
2709     return C->top();             // false path is dead; no test needed.
2710 
2711   // See if we get an immediate positive hit.  Happens roughly 83% of the
2712   // time.  Test to see if the value loaded just previously from the subklass
2713   // is exactly the superklass.
2714   IfNode *iff1 = gen_subtype_check_compare(*ctrl, superklass, nkls, BoolTest::eq, PROB_LIKELY(0.83f), gvn, T_ADDRESS);
2715   Node *iftrue1 = gvn->transform( new IfTrueNode (iff1));
2716   *ctrl = gvn->transform(new IfFalseNode(iff1));
2717 
2718   // Compile speed common case: Check for being deterministic right now.  If
2719   // chk_off is a constant and not equal to cacheoff then we are NOT a
2720   // subklass.  In this case we need exactly the 1 test above and we can
2721   // return those results immediately.
2722   if (!might_be_cache) {
2723     Node* not_subtype_ctrl = *ctrl;
2724     *ctrl = iftrue1; // We need exactly the 1 test above
2725     return not_subtype_ctrl;
2726   }
2727 
2728   // Gather the various success & failures here
2729   RegionNode *r_ok_subtype = new RegionNode(4);
2730   gvn->record_for_igvn(r_ok_subtype);
2731   RegionNode *r_not_subtype = new RegionNode(3);
2732   gvn->record_for_igvn(r_not_subtype);
2733 
2734   r_ok_subtype->init_req(1, iftrue1);
2735 
2736   // Check for immediate negative hit.  Happens roughly 11% of the time (which
2737   // is roughly 63% of the remaining cases).  Test to see if the loaded
2738   // check-offset points into the subklass display list or the 1-element
2739   // cache.  If it points to the display (and NOT the cache) and the display
2740   // missed then it's not a subtype.
2741   Node *cacheoff = gvn->intcon(cacheoff_con);
2742   IfNode *iff2 = gen_subtype_check_compare(*ctrl, chk_off, cacheoff, BoolTest::ne, PROB_LIKELY(0.63f), gvn, T_INT);
2743   r_not_subtype->init_req(1, gvn->transform(new IfTrueNode (iff2)));
2744   *ctrl = gvn->transform(new IfFalseNode(iff2));
2745 
2746   // Check for self.  Very rare to get here, but it is taken 1/3 the time.
2747   // No performance impact (too rare) but allows sharing of secondary arrays
2748   // which has some footprint reduction.
2749   IfNode *iff3 = gen_subtype_check_compare(*ctrl, subklass, superklass, BoolTest::eq, PROB_LIKELY(0.36f), gvn, T_ADDRESS);
2750   r_ok_subtype->init_req(2, gvn->transform(new IfTrueNode(iff3)));
2751   *ctrl = gvn->transform(new IfFalseNode(iff3));
2752 
2753   // -- Roads not taken here: --
2754   // We could also have chosen to perform the self-check at the beginning
2755   // of this code sequence, as the assembler does.  This would not pay off
2756   // the same way, since the optimizer, unlike the assembler, can perform
2757   // static type analysis to fold away many successful self-checks.
2758   // Non-foldable self checks work better here in second position, because
2759   // the initial primary superclass check subsumes a self-check for most
2760   // types.  An exception would be a secondary type like array-of-interface,
2761   // which does not appear in its own primary supertype display.
2762   // Finally, we could have chosen to move the self-check into the
2763   // PartialSubtypeCheckNode, and from there out-of-line in a platform
2764   // dependent manner.  But it is worthwhile to have the check here,
2765   // where it can be perhaps be optimized.  The cost in code space is
2766   // small (register compare, branch).
2767 
2768   // Now do a linear scan of the secondary super-klass array.  Again, no real
2769   // performance impact (too rare) but it's gotta be done.
2770   // Since the code is rarely used, there is no penalty for moving it
2771   // out of line, and it can only improve I-cache density.
2772   // The decision to inline or out-of-line this final check is platform
2773   // dependent, and is found in the AD file definition of PartialSubtypeCheck.
2774   Node* psc = gvn->transform(
2775     new PartialSubtypeCheckNode(*ctrl, subklass, superklass));
2776 
2777   IfNode *iff4 = gen_subtype_check_compare(*ctrl, psc, gvn->zerocon(T_OBJECT), BoolTest::ne, PROB_FAIR, gvn, T_ADDRESS);
2778   r_not_subtype->init_req(2, gvn->transform(new IfTrueNode (iff4)));
2779   r_ok_subtype ->init_req(3, gvn->transform(new IfFalseNode(iff4)));
2780 
2781   // Return false path; set default control to true path.
2782   *ctrl = gvn->transform(r_ok_subtype);
2783   return gvn->transform(r_not_subtype);
2784 }
2785 
2786 // Profile-driven exact type check:
2787 Node* GraphKit::type_check_receiver(Node* receiver, ciKlass* klass,
2788                                     float prob,
2789                                     Node* *casted_receiver) {
2790   const TypeKlassPtr* tklass = TypeKlassPtr::make(klass);
2791   Node* recv_klass = load_object_klass(receiver);
2792   Node* want_klass = makecon(tklass);
2793   Node* cmp = _gvn.transform( new CmpPNode(recv_klass, want_klass) );
2794   Node* bol = _gvn.transform( new BoolNode(cmp, BoolTest::eq) );
2795   IfNode* iff = create_and_xform_if(control(), bol, prob, COUNT_UNKNOWN);
2796   set_control( _gvn.transform( new IfTrueNode (iff) ));
2797   Node* fail = _gvn.transform( new IfFalseNode(iff) );
2798 
2799   const TypeOopPtr* recv_xtype = tklass->as_instance_type();
2800   assert(recv_xtype->klass_is_exact(), "");
2801 
2802   // Subsume downstream occurrences of receiver with a cast to
2803   // recv_xtype, since now we know what the type will be.
2804   Node* cast = new CheckCastPPNode(control(), receiver, recv_xtype);
2805   (*casted_receiver) = _gvn.transform(cast);
2806   // (User must make the replace_in_map call.)
2807 
2808   return fail;
2809 }
2810 
2811 //------------------------------subtype_check_receiver-------------------------
2812 Node* GraphKit::subtype_check_receiver(Node* receiver, ciKlass* klass,
2813                                        Node** casted_receiver) {
2814   const TypeKlassPtr* tklass = TypeKlassPtr::make(klass);
2815   Node* recv_klass = load_object_klass(receiver);
2816   Node* want_klass = makecon(tklass);
2817 
2818   Node* slow_ctl = gen_subtype_check(recv_klass, want_klass);
2819 
2820   // Cast receiver after successful check
2821   const TypeOopPtr* recv_type = tklass->cast_to_exactness(false)->is_klassptr()->as_instance_type();
2822   Node* cast = new CheckCastPPNode(control(), receiver, recv_type);
2823   (*casted_receiver) = _gvn.transform(cast);
2824 
2825   return slow_ctl;
2826 }
2827 
2828 //------------------------------seems_never_null-------------------------------
2829 // Use null_seen information if it is available from the profile.
2830 // If we see an unexpected null at a type check we record it and force a
2831 // recompile; the offending check will be recompiled to handle NULLs.
2832 // If we see several offending BCIs, then all checks in the
2833 // method will be recompiled.
2834 bool GraphKit::seems_never_null(Node* obj, ciProfileData* data, bool& speculating) {
2835   speculating = !_gvn.type(obj)->speculative_maybe_null();
2836   Deoptimization::DeoptReason reason = Deoptimization::reason_null_check(speculating);
2837   if (UncommonNullCast               // Cutout for this technique
2838       && obj != null()               // And not the -Xcomp stupid case?
2839       && !too_many_traps(reason)
2840       ) {
2841     if (speculating) {
2842       return true;
2843     }
2844     if (data == NULL)
2845       // Edge case:  no mature data.  Be optimistic here.
2846       return true;
2847     // If the profile has not seen a null, assume it won't happen.
2848     assert(java_bc() == Bytecodes::_checkcast ||
2849            java_bc() == Bytecodes::_instanceof ||
2850            java_bc() == Bytecodes::_aastore, "MDO must collect null_seen bit here");
2851     return !data->as_BitData()->null_seen();
2852   }
2853   speculating = false;
2854   return false;
2855 }
2856 
2857 void GraphKit::guard_klass_being_initialized(Node* klass) {
2858   int init_state_off = in_bytes(InstanceKlass::init_state_offset());
2859   Node* adr = basic_plus_adr(top(), klass, init_state_off);
2860   Node* init_state = LoadNode::make(_gvn, NULL, immutable_memory(), adr,
2861                                     adr->bottom_type()->is_ptr(), TypeInt::BYTE,
2862                                     T_BYTE, MemNode::unordered);
2863   init_state = _gvn.transform(init_state);
2864 
2865   Node* being_initialized_state = makecon(TypeInt::make(InstanceKlass::being_initialized));
2866 
2867   Node* chk = _gvn.transform(new CmpINode(being_initialized_state, init_state));
2868   Node* tst = _gvn.transform(new BoolNode(chk, BoolTest::eq));
2869 
2870   { BuildCutout unless(this, tst, PROB_MAX);
2871     uncommon_trap(Deoptimization::Reason_initialized, Deoptimization::Action_reinterpret);
2872   }
2873 }
2874 
2875 void GraphKit::guard_init_thread(Node* klass) {
2876   int init_thread_off = in_bytes(InstanceKlass::init_thread_offset());
2877   Node* adr = basic_plus_adr(top(), klass, init_thread_off);
2878 
2879   Node* init_thread = LoadNode::make(_gvn, NULL, immutable_memory(), adr,
2880                                      adr->bottom_type()->is_ptr(), TypePtr::NOTNULL,
2881                                      T_ADDRESS, MemNode::unordered);
2882   init_thread = _gvn.transform(init_thread);
2883 
2884   Node* cur_thread = _gvn.transform(new ThreadLocalNode());
2885 
2886   Node* chk = _gvn.transform(new CmpPNode(cur_thread, init_thread));
2887   Node* tst = _gvn.transform(new BoolNode(chk, BoolTest::eq));
2888 
2889   { BuildCutout unless(this, tst, PROB_MAX);
2890     uncommon_trap(Deoptimization::Reason_uninitialized, Deoptimization::Action_none);
2891   }
2892 }
2893 
2894 void GraphKit::clinit_barrier(ciInstanceKlass* ik, ciMethod* context) {
2895   if (ik->is_being_initialized()) {
2896     if (C->needs_clinit_barrier(ik, context)) {
2897       Node* klass = makecon(TypeKlassPtr::make(ik));
2898       guard_klass_being_initialized(klass);
2899       guard_init_thread(klass);
2900       insert_mem_bar(Op_MemBarCPUOrder);
2901     }
2902   } else if (ik->is_initialized()) {
2903     return; // no barrier needed
2904   } else {
2905     uncommon_trap(Deoptimization::Reason_uninitialized,
2906                   Deoptimization::Action_reinterpret,
2907                   NULL);
2908   }
2909 }
2910 
2911 //------------------------maybe_cast_profiled_receiver-------------------------
2912 // If the profile has seen exactly one type, narrow to exactly that type.
2913 // Subsequent type checks will always fold up.
2914 Node* GraphKit::maybe_cast_profiled_receiver(Node* not_null_obj,
2915                                              ciKlass* require_klass,
2916                                              ciKlass* spec_klass,
2917                                              bool safe_for_replace) {
2918   if (!UseTypeProfile || !TypeProfileCasts) return NULL;
2919 
2920   Deoptimization::DeoptReason reason = Deoptimization::reason_class_check(spec_klass != NULL);
2921 
2922   // Make sure we haven't already deoptimized from this tactic.
2923   if (too_many_traps_or_recompiles(reason))
2924     return NULL;
2925 
2926   // (No, this isn't a call, but it's enough like a virtual call
2927   // to use the same ciMethod accessor to get the profile info...)
2928   // If we have a speculative type use it instead of profiling (which
2929   // may not help us)
2930   ciKlass* exact_kls = spec_klass == NULL ? profile_has_unique_klass() : spec_klass;
2931   if (exact_kls != NULL) {// no cast failures here
2932     if (require_klass == NULL ||
2933         C->static_subtype_check(require_klass, exact_kls) == Compile::SSC_always_true) {
2934       // If we narrow the type to match what the type profile sees or
2935       // the speculative type, we can then remove the rest of the
2936       // cast.
2937       // This is a win, even if the exact_kls is very specific,
2938       // because downstream operations, such as method calls,
2939       // will often benefit from the sharper type.
2940       Node* exact_obj = not_null_obj; // will get updated in place...
2941       Node* slow_ctl  = type_check_receiver(exact_obj, exact_kls, 1.0,
2942                                             &exact_obj);
2943       { PreserveJVMState pjvms(this);
2944         set_control(slow_ctl);
2945         uncommon_trap_exact(reason, Deoptimization::Action_maybe_recompile);
2946       }
2947       if (safe_for_replace) {
2948         replace_in_map(not_null_obj, exact_obj);
2949       }
2950       return exact_obj;
2951     }
2952     // assert(ssc == Compile::SSC_always_true)... except maybe the profile lied to us.
2953   }
2954 
2955   return NULL;
2956 }
2957 
2958 /**
2959  * Cast obj to type and emit guard unless we had too many traps here
2960  * already
2961  *
2962  * @param obj       node being casted
2963  * @param type      type to cast the node to
2964  * @param not_null  true if we know node cannot be null
2965  */
2966 Node* GraphKit::maybe_cast_profiled_obj(Node* obj,
2967                                         ciKlass* type,
2968                                         bool not_null) {
2969   if (stopped()) {
2970     return obj;
2971   }
2972 
2973   // type == NULL if profiling tells us this object is always null
2974   if (type != NULL) {
2975     Deoptimization::DeoptReason class_reason = Deoptimization::Reason_speculate_class_check;
2976     Deoptimization::DeoptReason null_reason = Deoptimization::Reason_speculate_null_check;
2977 
2978     if (!too_many_traps_or_recompiles(null_reason) &&
2979         !too_many_traps_or_recompiles(class_reason)) {
2980       Node* not_null_obj = NULL;
2981       // not_null is true if we know the object is not null and
2982       // there's no need for a null check
2983       if (!not_null) {
2984         Node* null_ctl = top();
2985         not_null_obj = null_check_oop(obj, &null_ctl, true, true, true);
2986         assert(null_ctl->is_top(), "no null control here");
2987       } else {
2988         not_null_obj = obj;
2989       }
2990 
2991       Node* exact_obj = not_null_obj;
2992       ciKlass* exact_kls = type;
2993       Node* slow_ctl  = type_check_receiver(exact_obj, exact_kls, 1.0,
2994                                             &exact_obj);
2995       {
2996         PreserveJVMState pjvms(this);
2997         set_control(slow_ctl);
2998         uncommon_trap_exact(class_reason, Deoptimization::Action_maybe_recompile);
2999       }
3000       replace_in_map(not_null_obj, exact_obj);
3001       obj = exact_obj;
3002     }
3003   } else {
3004     if (!too_many_traps_or_recompiles(Deoptimization::Reason_null_assert)) {
3005       Node* exact_obj = null_assert(obj);
3006       replace_in_map(obj, exact_obj);
3007       obj = exact_obj;
3008     }
3009   }
3010   return obj;
3011 }
3012 
3013 //-------------------------------gen_instanceof--------------------------------
3014 // Generate an instance-of idiom.  Used by both the instance-of bytecode
3015 // and the reflective instance-of call.
3016 Node* GraphKit::gen_instanceof(Node* obj, Node* superklass, bool safe_for_replace) {
3017   kill_dead_locals();           // Benefit all the uncommon traps
3018   assert( !stopped(), "dead parse path should be checked in callers" );
3019   assert(!TypePtr::NULL_PTR->higher_equal(_gvn.type(superklass)->is_klassptr()),
3020          "must check for not-null not-dead klass in callers");
3021 
3022   // Make the merge point
3023   enum { _obj_path = 1, _fail_path, _null_path, PATH_LIMIT };
3024   RegionNode* region = new RegionNode(PATH_LIMIT);
3025   Node*       phi    = new PhiNode(region, TypeInt::BOOL);
3026   C->set_has_split_ifs(true); // Has chance for split-if optimization
3027 
3028   ciProfileData* data = NULL;
3029   if (java_bc() == Bytecodes::_instanceof) {  // Only for the bytecode
3030     data = method()->method_data()->bci_to_data(bci());
3031   }
3032   bool speculative_not_null = false;
3033   bool never_see_null = (ProfileDynamicTypes  // aggressive use of profile
3034                          && seems_never_null(obj, data, speculative_not_null));
3035 
3036   // Null check; get casted pointer; set region slot 3
3037   Node* null_ctl = top();
3038   Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null, safe_for_replace, speculative_not_null);
3039 
3040   // If not_null_obj is dead, only null-path is taken
3041   if (stopped()) {              // Doing instance-of on a NULL?
3042     set_control(null_ctl);
3043     return intcon(0);
3044   }
3045   region->init_req(_null_path, null_ctl);
3046   phi   ->init_req(_null_path, intcon(0)); // Set null path value
3047   if (null_ctl == top()) {
3048     // Do this eagerly, so that pattern matches like is_diamond_phi
3049     // will work even during parsing.
3050     assert(_null_path == PATH_LIMIT-1, "delete last");
3051     region->del_req(_null_path);
3052     phi   ->del_req(_null_path);
3053   }
3054 
3055   // Do we know the type check always succeed?
3056   bool known_statically = false;
3057   if (_gvn.type(superklass)->singleton()) {
3058     ciKlass* superk = _gvn.type(superklass)->is_klassptr()->klass();
3059     ciKlass* subk = _gvn.type(obj)->is_oopptr()->klass();
3060     if (subk != NULL && subk->is_loaded()) {
3061       int static_res = C->static_subtype_check(superk, subk);
3062       known_statically = (static_res == Compile::SSC_always_true || static_res == Compile::SSC_always_false);
3063     }
3064   }
3065 
3066   if (!known_statically) {
3067     const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
3068     // We may not have profiling here or it may not help us. If we
3069     // have a speculative type use it to perform an exact cast.
3070     ciKlass* spec_obj_type = obj_type->speculative_type();
3071     if (spec_obj_type != NULL || (ProfileDynamicTypes && data != NULL)) {
3072       Node* cast_obj = maybe_cast_profiled_receiver(not_null_obj, NULL, spec_obj_type, safe_for_replace);
3073       if (stopped()) {            // Profile disagrees with this path.
3074         set_control(null_ctl);    // Null is the only remaining possibility.
3075         return intcon(0);
3076       }
3077       if (cast_obj != NULL) {
3078         not_null_obj = cast_obj;
3079       }
3080     }
3081   }
3082 
3083   // Load the object's klass
3084   Node* obj_klass = load_object_klass(not_null_obj);
3085 
3086   // Generate the subtype check
3087   Node* not_subtype_ctrl = gen_subtype_check(obj_klass, superklass);
3088 
3089   // Plug in the success path to the general merge in slot 1.
3090   region->init_req(_obj_path, control());
3091   phi   ->init_req(_obj_path, intcon(1));
3092 
3093   // Plug in the failing path to the general merge in slot 2.
3094   region->init_req(_fail_path, not_subtype_ctrl);
3095   phi   ->init_req(_fail_path, intcon(0));
3096 
3097   // Return final merged results
3098   set_control( _gvn.transform(region) );
3099   record_for_igvn(region);
3100 
3101   // If we know the type check always succeeds then we don't use the
3102   // profiling data at this bytecode. Don't lose it, feed it to the
3103   // type system as a speculative type.
3104   if (safe_for_replace) {
3105     Node* casted_obj = record_profiled_receiver_for_speculation(obj);
3106     replace_in_map(obj, casted_obj);
3107   }
3108 
3109   return _gvn.transform(phi);
3110 }
3111 
3112 //-------------------------------gen_checkcast---------------------------------
3113 // Generate a checkcast idiom.  Used by both the checkcast bytecode and the
3114 // array store bytecode.  Stack must be as-if BEFORE doing the bytecode so the
3115 // uncommon-trap paths work.  Adjust stack after this call.
3116 // If failure_control is supplied and not null, it is filled in with
3117 // the control edge for the cast failure.  Otherwise, an appropriate
3118 // uncommon trap or exception is thrown.
3119 Node* GraphKit::gen_checkcast(Node *obj, Node* superklass,
3120                               Node* *failure_control) {
3121   kill_dead_locals();           // Benefit all the uncommon traps
3122   const TypeKlassPtr *tk = _gvn.type(superklass)->is_klassptr();
3123   const Type *toop = TypeOopPtr::make_from_klass(tk->klass());
3124 
3125   // Fast cutout:  Check the case that the cast is vacuously true.
3126   // This detects the common cases where the test will short-circuit
3127   // away completely.  We do this before we perform the null check,
3128   // because if the test is going to turn into zero code, we don't
3129   // want a residual null check left around.  (Causes a slowdown,
3130   // for example, in some objArray manipulations, such as a[i]=a[j].)
3131   if (tk->singleton()) {
3132     const TypeOopPtr* objtp = _gvn.type(obj)->isa_oopptr();
3133     if (objtp != NULL && objtp->klass() != NULL) {
3134       switch (C->static_subtype_check(tk->klass(), objtp->klass())) {
3135       case Compile::SSC_always_true:
3136         // If we know the type check always succeed then we don't use
3137         // the profiling data at this bytecode. Don't lose it, feed it
3138         // to the type system as a speculative type.
3139         return record_profiled_receiver_for_speculation(obj);
3140       case Compile::SSC_always_false:
3141         // It needs a null check because a null will *pass* the cast check.
3142         // A non-null value will always produce an exception.
3143         return null_assert(obj);
3144       }
3145     }
3146   }
3147 
3148   ciProfileData* data = NULL;
3149   bool safe_for_replace = false;
3150   if (failure_control == NULL) {        // use MDO in regular case only
3151     assert(java_bc() == Bytecodes::_aastore ||
3152            java_bc() == Bytecodes::_checkcast,
3153            "interpreter profiles type checks only for these BCs");
3154     data = method()->method_data()->bci_to_data(bci());
3155     safe_for_replace = true;
3156   }
3157 
3158   // Make the merge point
3159   enum { _obj_path = 1, _null_path, PATH_LIMIT };
3160   RegionNode* region = new RegionNode(PATH_LIMIT);
3161   Node*       phi    = new PhiNode(region, toop);
3162   C->set_has_split_ifs(true); // Has chance for split-if optimization
3163 
3164   // Use null-cast information if it is available
3165   bool speculative_not_null = false;
3166   bool never_see_null = ((failure_control == NULL)  // regular case only
3167                          && seems_never_null(obj, data, speculative_not_null));
3168 
3169   // Null check; get casted pointer; set region slot 3
3170   Node* null_ctl = top();
3171   Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null, safe_for_replace, speculative_not_null);
3172 
3173   // If not_null_obj is dead, only null-path is taken
3174   if (stopped()) {              // Doing instance-of on a NULL?
3175     set_control(null_ctl);
3176     return null();
3177   }
3178   region->init_req(_null_path, null_ctl);
3179   phi   ->init_req(_null_path, null());  // Set null path value
3180   if (null_ctl == top()) {
3181     // Do this eagerly, so that pattern matches like is_diamond_phi
3182     // will work even during parsing.
3183     assert(_null_path == PATH_LIMIT-1, "delete last");
3184     region->del_req(_null_path);
3185     phi   ->del_req(_null_path);
3186   }
3187 
3188   Node* cast_obj = NULL;
3189   if (tk->klass_is_exact()) {
3190     // The following optimization tries to statically cast the speculative type of the object
3191     // (for example obtained during profiling) to the type of the superklass and then do a
3192     // dynamic check that the type of the object is what we expect. To work correctly
3193     // for checkcast and aastore the type of superklass should be exact.
3194     const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
3195     // We may not have profiling here or it may not help us. If we have
3196     // a speculative type use it to perform an exact cast.
3197     ciKlass* spec_obj_type = obj_type->speculative_type();
3198     if (spec_obj_type != NULL || data != NULL) {
3199       cast_obj = maybe_cast_profiled_receiver(not_null_obj, tk->klass(), spec_obj_type, safe_for_replace);
3200       if (cast_obj != NULL) {
3201         if (failure_control != NULL) // failure is now impossible
3202           (*failure_control) = top();
3203         // adjust the type of the phi to the exact klass:
3204         phi->raise_bottom_type(_gvn.type(cast_obj)->meet_speculative(TypePtr::NULL_PTR));
3205       }
3206     }
3207   }
3208 
3209   if (cast_obj == NULL) {
3210     // Load the object's klass
3211     Node* obj_klass = load_object_klass(not_null_obj);
3212 
3213     // Generate the subtype check
3214     Node* not_subtype_ctrl = gen_subtype_check( obj_klass, superklass );
3215 
3216     // Plug in success path into the merge
3217     cast_obj = _gvn.transform(new CheckCastPPNode(control(), not_null_obj, toop));
3218     // Failure path ends in uncommon trap (or may be dead - failure impossible)
3219     if (failure_control == NULL) {
3220       if (not_subtype_ctrl != top()) { // If failure is possible
3221         PreserveJVMState pjvms(this);
3222         set_control(not_subtype_ctrl);
3223         builtin_throw(Deoptimization::Reason_class_check, obj_klass);
3224       }
3225     } else {
3226       (*failure_control) = not_subtype_ctrl;
3227     }
3228   }
3229 
3230   region->init_req(_obj_path, control());
3231   phi   ->init_req(_obj_path, cast_obj);
3232 
3233   // A merge of NULL or Casted-NotNull obj
3234   Node* res = _gvn.transform(phi);
3235 
3236   // Note I do NOT always 'replace_in_map(obj,result)' here.
3237   //  if( tk->klass()->can_be_primary_super()  )
3238     // This means that if I successfully store an Object into an array-of-String
3239     // I 'forget' that the Object is really now known to be a String.  I have to
3240     // do this because we don't have true union types for interfaces - if I store
3241     // a Baz into an array-of-Interface and then tell the optimizer it's an
3242     // Interface, I forget that it's also a Baz and cannot do Baz-like field
3243     // references to it.  FIX THIS WHEN UNION TYPES APPEAR!
3244   //  replace_in_map( obj, res );
3245 
3246   // Return final merged results
3247   set_control( _gvn.transform(region) );
3248   record_for_igvn(region);
3249 
3250   return record_profiled_receiver_for_speculation(res);
3251 }
3252 
3253 //------------------------------next_monitor-----------------------------------
3254 // What number should be given to the next monitor?
3255 int GraphKit::next_monitor() {
3256   int current = jvms()->monitor_depth()* C->sync_stack_slots();
3257   int next = current + C->sync_stack_slots();
3258   // Keep the toplevel high water mark current:
3259   if (C->fixed_slots() < next)  C->set_fixed_slots(next);
3260   return current;
3261 }
3262 
3263 //------------------------------insert_mem_bar---------------------------------
3264 // Memory barrier to avoid floating things around
3265 // The membar serves as a pinch point between both control and all memory slices.
3266 Node* GraphKit::insert_mem_bar(int opcode, Node* precedent) {
3267   MemBarNode* mb = MemBarNode::make(C, opcode, Compile::AliasIdxBot, precedent);
3268   mb->init_req(TypeFunc::Control, control());
3269   mb->init_req(TypeFunc::Memory,  reset_memory());
3270   Node* membar = _gvn.transform(mb);
3271   set_control(_gvn.transform(new ProjNode(membar, TypeFunc::Control)));
3272   set_all_memory_call(membar);
3273   return membar;
3274 }
3275 
3276 //-------------------------insert_mem_bar_volatile----------------------------
3277 // Memory barrier to avoid floating things around
3278 // The membar serves as a pinch point between both control and memory(alias_idx).
3279 // If you want to make a pinch point on all memory slices, do not use this
3280 // function (even with AliasIdxBot); use insert_mem_bar() instead.
3281 Node* GraphKit::insert_mem_bar_volatile(int opcode, int alias_idx, Node* precedent) {
3282   // When Parse::do_put_xxx updates a volatile field, it appends a series
3283   // of MemBarVolatile nodes, one for *each* volatile field alias category.
3284   // The first membar is on the same memory slice as the field store opcode.
3285   // This forces the membar to follow the store.  (Bug 6500685 broke this.)
3286   // All the other membars (for other volatile slices, including AliasIdxBot,
3287   // which stands for all unknown volatile slices) are control-dependent
3288   // on the first membar.  This prevents later volatile loads or stores
3289   // from sliding up past the just-emitted store.
3290 
3291   MemBarNode* mb = MemBarNode::make(C, opcode, alias_idx, precedent);
3292   mb->set_req(TypeFunc::Control,control());
3293   if (alias_idx == Compile::AliasIdxBot) {
3294     mb->set_req(TypeFunc::Memory, merged_memory()->base_memory());
3295   } else {
3296     assert(!(opcode == Op_Initialize && alias_idx != Compile::AliasIdxRaw), "fix caller");
3297     mb->set_req(TypeFunc::Memory, memory(alias_idx));
3298   }
3299   Node* membar = _gvn.transform(mb);
3300   set_control(_gvn.transform(new ProjNode(membar, TypeFunc::Control)));
3301   if (alias_idx == Compile::AliasIdxBot) {
3302     merged_memory()->set_base_memory(_gvn.transform(new ProjNode(membar, TypeFunc::Memory)));
3303   } else {
3304     set_memory(_gvn.transform(new ProjNode(membar, TypeFunc::Memory)),alias_idx);
3305   }
3306   return membar;
3307 }
3308 
3309 void GraphKit::insert_store_load_for_barrier() {
3310   Node* mem = reset_memory();
3311   MemBarNode* mb = MemBarNode::make(C, Op_MemBarVolatile, Compile::AliasIdxRaw);
3312   mb->init_req(TypeFunc::Control, control());
3313   mb->init_req(TypeFunc::Memory, mem);
3314   Node* membar = _gvn.transform(mb);
3315   set_control(_gvn.transform(new ProjNode(membar, TypeFunc::Control)));
3316   Node* newmem = _gvn.transform(new ProjNode(membar, TypeFunc::Memory));
3317   set_all_memory(mem);
3318   set_memory(newmem, Compile::AliasIdxRaw);
3319 }
3320 
3321 //------------------------------shared_lock------------------------------------
3322 // Emit locking code.
3323 FastLockNode* GraphKit::shared_lock(Node* obj) {
3324   // bci is either a monitorenter bc or InvocationEntryBci
3325   // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
3326   assert(SynchronizationEntryBCI == InvocationEntryBci, "");
3327 
3328   if( !GenerateSynchronizationCode )
3329     return NULL;                // Not locking things?
3330   if (stopped())                // Dead monitor?
3331     return NULL;
3332 
3333   assert(dead_locals_are_killed(), "should kill locals before sync. point");
3334 
3335   obj = access_resolve(obj, ACCESS_READ | ACCESS_WRITE);
3336 
3337   // Box the stack location
3338   Node* box = _gvn.transform(new BoxLockNode(next_monitor()));
3339   Node* mem = reset_memory();
3340 
3341   FastLockNode * flock = _gvn.transform(new FastLockNode(0, obj, box) )->as_FastLock();
3342   if (UseBiasedLocking && PrintPreciseBiasedLockingStatistics) {
3343     // Create the counters for this fast lock.
3344     flock->create_lock_counter(sync_jvms()); // sync_jvms used to get current bci
3345   }
3346 
3347   // Create the rtm counters for this fast lock if needed.
3348   flock->create_rtm_lock_counter(sync_jvms()); // sync_jvms used to get current bci
3349 
3350   // Add monitor to debug info for the slow path.  If we block inside the
3351   // slow path and de-opt, we need the monitor hanging around
3352   map()->push_monitor( flock );
3353 
3354   const TypeFunc *tf = LockNode::lock_type();
3355   LockNode *lock = new LockNode(C, tf);
3356 
3357   lock->init_req( TypeFunc::Control, control() );
3358   lock->init_req( TypeFunc::Memory , mem );
3359   lock->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
3360   lock->init_req( TypeFunc::FramePtr, frameptr() );
3361   lock->init_req( TypeFunc::ReturnAdr, top() );
3362 
3363   lock->init_req(TypeFunc::Parms + 0, obj);
3364   lock->init_req(TypeFunc::Parms + 1, box);
3365   lock->init_req(TypeFunc::Parms + 2, flock);
3366   add_safepoint_edges(lock);
3367 
3368   lock = _gvn.transform( lock )->as_Lock();
3369 
3370   // lock has no side-effects, sets few values
3371   set_predefined_output_for_runtime_call(lock, mem, TypeRawPtr::BOTTOM);
3372 
3373   insert_mem_bar(Op_MemBarAcquireLock);
3374 
3375   // Add this to the worklist so that the lock can be eliminated
3376   record_for_igvn(lock);
3377 
3378 #ifndef PRODUCT
3379   if (PrintLockStatistics) {
3380     // Update the counter for this lock.  Don't bother using an atomic
3381     // operation since we don't require absolute accuracy.
3382     lock->create_lock_counter(map()->jvms());
3383     increment_counter(lock->counter()->addr());
3384   }
3385 #endif
3386 
3387   return flock;
3388 }
3389 
3390 
3391 //------------------------------shared_unlock----------------------------------
3392 // Emit unlocking code.
3393 void GraphKit::shared_unlock(Node* box, Node* obj) {
3394   // bci is either a monitorenter bc or InvocationEntryBci
3395   // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
3396   assert(SynchronizationEntryBCI == InvocationEntryBci, "");
3397 
3398   if( !GenerateSynchronizationCode )
3399     return;
3400   if (stopped()) {               // Dead monitor?
3401     map()->pop_monitor();        // Kill monitor from debug info
3402     return;
3403   }
3404 
3405   // Memory barrier to avoid floating things down past the locked region
3406   insert_mem_bar(Op_MemBarReleaseLock);
3407 
3408   const TypeFunc *tf = OptoRuntime::complete_monitor_exit_Type();
3409   UnlockNode *unlock = new UnlockNode(C, tf);
3410 #ifdef ASSERT
3411   unlock->set_dbg_jvms(sync_jvms());
3412 #endif
3413   uint raw_idx = Compile::AliasIdxRaw;
3414   unlock->init_req( TypeFunc::Control, control() );
3415   unlock->init_req( TypeFunc::Memory , memory(raw_idx) );
3416   unlock->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
3417   unlock->init_req( TypeFunc::FramePtr, frameptr() );
3418   unlock->init_req( TypeFunc::ReturnAdr, top() );
3419 
3420   unlock->init_req(TypeFunc::Parms + 0, obj);
3421   unlock->init_req(TypeFunc::Parms + 1, box);
3422   unlock = _gvn.transform(unlock)->as_Unlock();
3423 
3424   Node* mem = reset_memory();
3425 
3426   // unlock has no side-effects, sets few values
3427   set_predefined_output_for_runtime_call(unlock, mem, TypeRawPtr::BOTTOM);
3428 
3429   // Kill monitor from debug info
3430   map()->pop_monitor( );
3431 }
3432 
3433 //-------------------------------get_layout_helper-----------------------------
3434 // If the given klass is a constant or known to be an array,
3435 // fetch the constant layout helper value into constant_value
3436 // and return (Node*)NULL.  Otherwise, load the non-constant
3437 // layout helper value, and return the node which represents it.
3438 // This two-faced routine is useful because allocation sites
3439 // almost always feature constant types.
3440 Node* GraphKit::get_layout_helper(Node* klass_node, jint& constant_value) {
3441   const TypeKlassPtr* inst_klass = _gvn.type(klass_node)->isa_klassptr();
3442   if (!StressReflectiveCode && inst_klass != NULL) {
3443     ciKlass* klass = inst_klass->klass();
3444     bool    xklass = inst_klass->klass_is_exact();
3445     if (xklass || klass->is_array_klass()) {
3446       jint lhelper = klass->layout_helper();
3447       if (lhelper != Klass::_lh_neutral_value) {
3448         constant_value = lhelper;
3449         return (Node*) NULL;
3450       }
3451     }
3452   }
3453   constant_value = Klass::_lh_neutral_value;  // put in a known value
3454   Node* lhp = basic_plus_adr(klass_node, klass_node, in_bytes(Klass::layout_helper_offset()));
3455   return make_load(NULL, lhp, TypeInt::INT, T_INT, MemNode::unordered);
3456 }
3457 
3458 // We just put in an allocate/initialize with a big raw-memory effect.
3459 // Hook selected additional alias categories on the initialization.
3460 static void hook_memory_on_init(GraphKit& kit, int alias_idx,
3461                                 MergeMemNode* init_in_merge,
3462                                 Node* init_out_raw) {
3463   DEBUG_ONLY(Node* init_in_raw = init_in_merge->base_memory());
3464   assert(init_in_merge->memory_at(alias_idx) == init_in_raw, "");
3465 
3466   Node* prevmem = kit.memory(alias_idx);
3467   init_in_merge->set_memory_at(alias_idx, prevmem);
3468   kit.set_memory(init_out_raw, alias_idx);
3469 }
3470 
3471 //---------------------------set_output_for_allocation-------------------------
3472 Node* GraphKit::set_output_for_allocation(AllocateNode* alloc,
3473                                           const TypeOopPtr* oop_type,
3474                                           bool deoptimize_on_exception) {
3475   int rawidx = Compile::AliasIdxRaw;
3476   alloc->set_req( TypeFunc::FramePtr, frameptr() );
3477   add_safepoint_edges(alloc);
3478   Node* allocx = _gvn.transform(alloc);
3479   set_control( _gvn.transform(new ProjNode(allocx, TypeFunc::Control) ) );
3480   // create memory projection for i_o
3481   set_memory ( _gvn.transform( new ProjNode(allocx, TypeFunc::Memory, true) ), rawidx );
3482   make_slow_call_ex(allocx, env()->Throwable_klass(), true, deoptimize_on_exception);
3483 
3484   // create a memory projection as for the normal control path
3485   Node* malloc = _gvn.transform(new ProjNode(allocx, TypeFunc::Memory));
3486   set_memory(malloc, rawidx);
3487 
3488   // a normal slow-call doesn't change i_o, but an allocation does
3489   // we create a separate i_o projection for the normal control path
3490   set_i_o(_gvn.transform( new ProjNode(allocx, TypeFunc::I_O, false) ) );
3491   Node* rawoop = _gvn.transform( new ProjNode(allocx, TypeFunc::Parms) );
3492 
3493   // put in an initialization barrier
3494   InitializeNode* init = insert_mem_bar_volatile(Op_Initialize, rawidx,
3495                                                  rawoop)->as_Initialize();
3496   assert(alloc->initialization() == init,  "2-way macro link must work");
3497   assert(init ->allocation()     == alloc, "2-way macro link must work");
3498   {
3499     // Extract memory strands which may participate in the new object's
3500     // initialization, and source them from the new InitializeNode.
3501     // This will allow us to observe initializations when they occur,
3502     // and link them properly (as a group) to the InitializeNode.
3503     assert(init->in(InitializeNode::Memory) == malloc, "");
3504     MergeMemNode* minit_in = MergeMemNode::make(malloc);
3505     init->set_req(InitializeNode::Memory, minit_in);
3506     record_for_igvn(minit_in); // fold it up later, if possible
3507     Node* minit_out = memory(rawidx);
3508     assert(minit_out->is_Proj() && minit_out->in(0) == init, "");
3509     // Add an edge in the MergeMem for the header fields so an access
3510     // to one of those has correct memory state
3511     set_memory(minit_out, C->get_alias_index(oop_type->add_offset(oopDesc::mark_offset_in_bytes())));
3512     set_memory(minit_out, C->get_alias_index(oop_type->add_offset(oopDesc::klass_offset_in_bytes())));
3513     if (oop_type->isa_aryptr()) {
3514       const TypePtr* telemref = oop_type->add_offset(Type::OffsetBot);
3515       int            elemidx  = C->get_alias_index(telemref);
3516       hook_memory_on_init(*this, elemidx, minit_in, minit_out);
3517     } else if (oop_type->isa_instptr()) {
3518       ciInstanceKlass* ik = oop_type->klass()->as_instance_klass();
3519       for (int i = 0, len = ik->nof_nonstatic_fields(); i < len; i++) {
3520         ciField* field = ik->nonstatic_field_at(i);
3521         if (field->offset() >= TrackedInitializationLimit * HeapWordSize)
3522           continue;  // do not bother to track really large numbers of fields
3523         // Find (or create) the alias category for this field:
3524         int fieldidx = C->alias_type(field)->index();
3525         hook_memory_on_init(*this, fieldidx, minit_in, minit_out);
3526       }
3527     }
3528   }
3529 
3530   // Cast raw oop to the real thing...
3531   Node* javaoop = new CheckCastPPNode(control(), rawoop, oop_type);
3532   javaoop = _gvn.transform(javaoop);
3533   C->set_recent_alloc(control(), javaoop);
3534   assert(just_allocated_object(control()) == javaoop, "just allocated");
3535 
3536 #ifdef ASSERT
3537   { // Verify that the AllocateNode::Ideal_allocation recognizers work:
3538     assert(AllocateNode::Ideal_allocation(rawoop, &_gvn) == alloc,
3539            "Ideal_allocation works");
3540     assert(AllocateNode::Ideal_allocation(javaoop, &_gvn) == alloc,
3541            "Ideal_allocation works");
3542     if (alloc->is_AllocateArray()) {
3543       assert(AllocateArrayNode::Ideal_array_allocation(rawoop, &_gvn) == alloc->as_AllocateArray(),
3544              "Ideal_allocation works");
3545       assert(AllocateArrayNode::Ideal_array_allocation(javaoop, &_gvn) == alloc->as_AllocateArray(),
3546              "Ideal_allocation works");
3547     } else {
3548       assert(alloc->in(AllocateNode::ALength)->is_top(), "no length, please");
3549     }
3550   }
3551 #endif //ASSERT
3552 
3553   return javaoop;
3554 }
3555 
3556 //---------------------------new_instance--------------------------------------
3557 // This routine takes a klass_node which may be constant (for a static type)
3558 // or may be non-constant (for reflective code).  It will work equally well
3559 // for either, and the graph will fold nicely if the optimizer later reduces
3560 // the type to a constant.
3561 // The optional arguments are for specialized use by intrinsics:
3562 //  - If 'extra_slow_test' if not null is an extra condition for the slow-path.
3563 //  - If 'return_size_val', report the the total object size to the caller.
3564 //  - deoptimize_on_exception controls how Java exceptions are handled (rethrow vs deoptimize)
3565 Node* GraphKit::new_instance(Node* klass_node,
3566                              Node* extra_slow_test,
3567                              Node* *return_size_val,
3568                              bool deoptimize_on_exception) {
3569   // Compute size in doublewords
3570   // The size is always an integral number of doublewords, represented
3571   // as a positive bytewise size stored in the klass's layout_helper.
3572   // The layout_helper also encodes (in a low bit) the need for a slow path.
3573   jint  layout_con = Klass::_lh_neutral_value;
3574   Node* layout_val = get_layout_helper(klass_node, layout_con);
3575   int   layout_is_con = (layout_val == NULL);
3576 
3577   if (extra_slow_test == NULL)  extra_slow_test = intcon(0);
3578   // Generate the initial go-slow test.  It's either ALWAYS (return a
3579   // Node for 1) or NEVER (return a NULL) or perhaps (in the reflective
3580   // case) a computed value derived from the layout_helper.
3581   Node* initial_slow_test = NULL;
3582   if (layout_is_con) {
3583     assert(!StressReflectiveCode, "stress mode does not use these paths");
3584     bool must_go_slow = Klass::layout_helper_needs_slow_path(layout_con);
3585     initial_slow_test = must_go_slow ? intcon(1) : extra_slow_test;
3586   } else {   // reflective case
3587     // This reflective path is used by Unsafe.allocateInstance.
3588     // (It may be stress-tested by specifying StressReflectiveCode.)
3589     // Basically, we want to get into the VM is there's an illegal argument.
3590     Node* bit = intcon(Klass::_lh_instance_slow_path_bit);
3591     initial_slow_test = _gvn.transform( new AndINode(layout_val, bit) );
3592     if (extra_slow_test != intcon(0)) {
3593       initial_slow_test = _gvn.transform( new OrINode(initial_slow_test, extra_slow_test) );
3594     }
3595     // (Macro-expander will further convert this to a Bool, if necessary.)
3596   }
3597 
3598   // Find the size in bytes.  This is easy; it's the layout_helper.
3599   // The size value must be valid even if the slow path is taken.
3600   Node* size = NULL;
3601   if (layout_is_con) {
3602     size = MakeConX(Klass::layout_helper_size_in_bytes(layout_con));
3603   } else {   // reflective case
3604     // This reflective path is used by clone and Unsafe.allocateInstance.
3605     size = ConvI2X(layout_val);
3606 
3607     // Clear the low bits to extract layout_helper_size_in_bytes:
3608     assert((int)Klass::_lh_instance_slow_path_bit < BytesPerLong, "clear bit");
3609     Node* mask = MakeConX(~ (intptr_t)right_n_bits(LogBytesPerLong));
3610     size = _gvn.transform( new AndXNode(size, mask) );
3611   }
3612   if (return_size_val != NULL) {
3613     (*return_size_val) = size;
3614   }
3615 
3616   // This is a precise notnull oop of the klass.
3617   // (Actually, it need not be precise if this is a reflective allocation.)
3618   // It's what we cast the result to.
3619   const TypeKlassPtr* tklass = _gvn.type(klass_node)->isa_klassptr();
3620   if (!tklass)  tklass = TypeKlassPtr::OBJECT;
3621   const TypeOopPtr* oop_type = tklass->as_instance_type();
3622 
3623   // Now generate allocation code
3624 
3625   // The entire memory state is needed for slow path of the allocation
3626   // since GC and deoptimization can happened.
3627   Node *mem = reset_memory();
3628   set_all_memory(mem); // Create new memory state
3629 
3630   AllocateNode* alloc = new AllocateNode(C, AllocateNode::alloc_type(Type::TOP),
3631                                          control(), mem, i_o(),
3632                                          size, klass_node,
3633                                          initial_slow_test);
3634 
3635   return set_output_for_allocation(alloc, oop_type, deoptimize_on_exception);
3636 }
3637 
3638 //-------------------------------new_array-------------------------------------
3639 // helper for both newarray and anewarray
3640 // The 'length' parameter is (obviously) the length of the array.
3641 // See comments on new_instance for the meaning of the other arguments.
3642 Node* GraphKit::new_array(Node* klass_node,     // array klass (maybe variable)
3643                           Node* length,         // number of array elements
3644                           int   nargs,          // number of arguments to push back for uncommon trap
3645                           Node* *return_size_val,
3646                           bool deoptimize_on_exception) {
3647   jint  layout_con = Klass::_lh_neutral_value;
3648   Node* layout_val = get_layout_helper(klass_node, layout_con);
3649   int   layout_is_con = (layout_val == NULL);
3650 
3651   if (!layout_is_con && !StressReflectiveCode &&
3652       !too_many_traps(Deoptimization::Reason_class_check)) {
3653     // This is a reflective array creation site.
3654     // Optimistically assume that it is a subtype of Object[],
3655     // so that we can fold up all the address arithmetic.
3656     layout_con = Klass::array_layout_helper(T_OBJECT);
3657     Node* cmp_lh = _gvn.transform( new CmpINode(layout_val, intcon(layout_con)) );
3658     Node* bol_lh = _gvn.transform( new BoolNode(cmp_lh, BoolTest::eq) );
3659     { BuildCutout unless(this, bol_lh, PROB_MAX);
3660       inc_sp(nargs);
3661       uncommon_trap(Deoptimization::Reason_class_check,
3662                     Deoptimization::Action_maybe_recompile);
3663     }
3664     layout_val = NULL;
3665     layout_is_con = true;
3666   }
3667 
3668   // Generate the initial go-slow test.  Make sure we do not overflow
3669   // if length is huge (near 2Gig) or negative!  We do not need
3670   // exact double-words here, just a close approximation of needed
3671   // double-words.  We can't add any offset or rounding bits, lest we
3672   // take a size -1 of bytes and make it positive.  Use an unsigned
3673   // compare, so negative sizes look hugely positive.
3674   int fast_size_limit = FastAllocateSizeLimit;
3675   if (layout_is_con) {
3676     assert(!StressReflectiveCode, "stress mode does not use these paths");
3677     // Increase the size limit if we have exact knowledge of array type.
3678     int log2_esize = Klass::layout_helper_log2_element_size(layout_con);
3679     fast_size_limit <<= (LogBytesPerLong - log2_esize);
3680   }
3681 
3682   Node* initial_slow_cmp  = _gvn.transform( new CmpUNode( length, intcon( fast_size_limit ) ) );
3683   Node* initial_slow_test = _gvn.transform( new BoolNode( initial_slow_cmp, BoolTest::gt ) );
3684 
3685   // --- Size Computation ---
3686   // array_size = round_to_heap(array_header + (length << elem_shift));
3687   // where round_to_heap(x) == align_to(x, MinObjAlignmentInBytes)
3688   // and align_to(x, y) == ((x + y-1) & ~(y-1))
3689   // The rounding mask is strength-reduced, if possible.
3690   int round_mask = MinObjAlignmentInBytes - 1;
3691   Node* header_size = NULL;
3692   int   header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
3693   // (T_BYTE has the weakest alignment and size restrictions...)
3694   if (layout_is_con) {
3695     int       hsize  = Klass::layout_helper_header_size(layout_con);
3696     int       eshift = Klass::layout_helper_log2_element_size(layout_con);
3697     BasicType etype  = Klass::layout_helper_element_type(layout_con);
3698     if ((round_mask & ~right_n_bits(eshift)) == 0)
3699       round_mask = 0;  // strength-reduce it if it goes away completely
3700     assert((hsize & right_n_bits(eshift)) == 0, "hsize is pre-rounded");
3701     assert(header_size_min <= hsize, "generic minimum is smallest");
3702     header_size_min = hsize;
3703     header_size = intcon(hsize + round_mask);
3704   } else {
3705     Node* hss   = intcon(Klass::_lh_header_size_shift);
3706     Node* hsm   = intcon(Klass::_lh_header_size_mask);
3707     Node* hsize = _gvn.transform( new URShiftINode(layout_val, hss) );
3708     hsize       = _gvn.transform( new AndINode(hsize, hsm) );
3709     Node* mask  = intcon(round_mask);
3710     header_size = _gvn.transform( new AddINode(hsize, mask) );
3711   }
3712 
3713   Node* elem_shift = NULL;
3714   if (layout_is_con) {
3715     int eshift = Klass::layout_helper_log2_element_size(layout_con);
3716     if (eshift != 0)
3717       elem_shift = intcon(eshift);
3718   } else {
3719     // There is no need to mask or shift this value.
3720     // The semantics of LShiftINode include an implicit mask to 0x1F.
3721     assert(Klass::_lh_log2_element_size_shift == 0, "use shift in place");
3722     elem_shift = layout_val;
3723   }
3724 
3725   // Transition to native address size for all offset calculations:
3726   Node* lengthx = ConvI2X(length);
3727   Node* headerx = ConvI2X(header_size);
3728 #ifdef _LP64
3729   { const TypeInt* tilen = _gvn.find_int_type(length);
3730     if (tilen != NULL && tilen->_lo < 0) {
3731       // Add a manual constraint to a positive range.  Cf. array_element_address.
3732       jint size_max = fast_size_limit;
3733       if (size_max > tilen->_hi)  size_max = tilen->_hi;
3734       const TypeInt* tlcon = TypeInt::make(0, size_max, Type::WidenMin);
3735 
3736       // Only do a narrow I2L conversion if the range check passed.
3737       IfNode* iff = new IfNode(control(), initial_slow_test, PROB_MIN, COUNT_UNKNOWN);
3738       _gvn.transform(iff);
3739       RegionNode* region = new RegionNode(3);
3740       _gvn.set_type(region, Type::CONTROL);
3741       lengthx = new PhiNode(region, TypeLong::LONG);
3742       _gvn.set_type(lengthx, TypeLong::LONG);
3743 
3744       // Range check passed. Use ConvI2L node with narrow type.
3745       Node* passed = IfFalse(iff);
3746       region->init_req(1, passed);
3747       // Make I2L conversion control dependent to prevent it from
3748       // floating above the range check during loop optimizations.
3749       lengthx->init_req(1, C->constrained_convI2L(&_gvn, length, tlcon, passed));
3750 
3751       // Range check failed. Use ConvI2L with wide type because length may be invalid.
3752       region->init_req(2, IfTrue(iff));
3753       lengthx->init_req(2, ConvI2X(length));
3754 
3755       set_control(region);
3756       record_for_igvn(region);
3757       record_for_igvn(lengthx);
3758     }
3759   }
3760 #endif
3761 
3762   // Combine header size (plus rounding) and body size.  Then round down.
3763   // This computation cannot overflow, because it is used only in two
3764   // places, one where the length is sharply limited, and the other
3765   // after a successful allocation.
3766   Node* abody = lengthx;
3767   if (elem_shift != NULL)
3768     abody     = _gvn.transform( new LShiftXNode(lengthx, elem_shift) );
3769   Node* size  = _gvn.transform( new AddXNode(headerx, abody) );
3770   if (round_mask != 0) {
3771     Node* mask = MakeConX(~round_mask);
3772     size       = _gvn.transform( new AndXNode(size, mask) );
3773   }
3774   // else if round_mask == 0, the size computation is self-rounding
3775 
3776   if (return_size_val != NULL) {
3777     // This is the size
3778     (*return_size_val) = size;
3779   }
3780 
3781   // Now generate allocation code
3782 
3783   // The entire memory state is needed for slow path of the allocation
3784   // since GC and deoptimization can happened.
3785   Node *mem = reset_memory();
3786   set_all_memory(mem); // Create new memory state
3787 
3788   if (initial_slow_test->is_Bool()) {
3789     // Hide it behind a CMoveI, or else PhaseIdealLoop::split_up will get sick.
3790     initial_slow_test = initial_slow_test->as_Bool()->as_int_value(&_gvn);
3791   }
3792 
3793   // Create the AllocateArrayNode and its result projections
3794   AllocateArrayNode* alloc
3795     = new AllocateArrayNode(C, AllocateArrayNode::alloc_type(TypeInt::INT),
3796                             control(), mem, i_o(),
3797                             size, klass_node,
3798                             initial_slow_test,
3799                             length);
3800 
3801   // Cast to correct type.  Note that the klass_node may be constant or not,
3802   // and in the latter case the actual array type will be inexact also.
3803   // (This happens via a non-constant argument to inline_native_newArray.)
3804   // In any case, the value of klass_node provides the desired array type.
3805   const TypeInt* length_type = _gvn.find_int_type(length);
3806   const TypeOopPtr* ary_type = _gvn.type(klass_node)->is_klassptr()->as_instance_type();
3807   if (ary_type->isa_aryptr() && length_type != NULL) {
3808     // Try to get a better type than POS for the size
3809     ary_type = ary_type->is_aryptr()->cast_to_size(length_type);
3810   }
3811 
3812   Node* javaoop = set_output_for_allocation(alloc, ary_type, deoptimize_on_exception);
3813 
3814   // Cast length on remaining path to be as narrow as possible
3815   if (map()->find_edge(length) >= 0) {
3816     Node* ccast = alloc->make_ideal_length(ary_type, &_gvn);
3817     if (ccast != length) {
3818       _gvn.set_type_bottom(ccast);
3819       record_for_igvn(ccast);
3820       replace_in_map(length, ccast);
3821     }
3822   }
3823 
3824   return javaoop;
3825 }
3826 
3827 // The following "Ideal_foo" functions are placed here because they recognize
3828 // the graph shapes created by the functions immediately above.
3829 
3830 //---------------------------Ideal_allocation----------------------------------
3831 // Given an oop pointer or raw pointer, see if it feeds from an AllocateNode.
3832 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase) {
3833   if (ptr == NULL) {     // reduce dumb test in callers
3834     return NULL;
3835   }
3836 
3837   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
3838   ptr = bs->step_over_gc_barrier(ptr);
3839 
3840   if (ptr->is_CheckCastPP()) { // strip only one raw-to-oop cast
3841     ptr = ptr->in(1);
3842     if (ptr == NULL) return NULL;
3843   }
3844   // Return NULL for allocations with several casts:
3845   //   j.l.reflect.Array.newInstance(jobject, jint)
3846   //   Object.clone()
3847   // to keep more precise type from last cast.
3848   if (ptr->is_Proj()) {
3849     Node* allo = ptr->in(0);
3850     if (allo != NULL && allo->is_Allocate()) {
3851       return allo->as_Allocate();
3852     }
3853   }
3854   // Report failure to match.
3855   return NULL;
3856 }
3857 
3858 // Fancy version which also strips off an offset (and reports it to caller).
3859 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase,
3860                                              intptr_t& offset) {
3861   Node* base = AddPNode::Ideal_base_and_offset(ptr, phase, offset);
3862   if (base == NULL)  return NULL;
3863   return Ideal_allocation(base, phase);
3864 }
3865 
3866 // Trace Initialize <- Proj[Parm] <- Allocate
3867 AllocateNode* InitializeNode::allocation() {
3868   Node* rawoop = in(InitializeNode::RawAddress);
3869   if (rawoop->is_Proj()) {
3870     Node* alloc = rawoop->in(0);
3871     if (alloc->is_Allocate()) {
3872       return alloc->as_Allocate();
3873     }
3874   }
3875   return NULL;
3876 }
3877 
3878 // Trace Allocate -> Proj[Parm] -> Initialize
3879 InitializeNode* AllocateNode::initialization() {
3880   ProjNode* rawoop = proj_out_or_null(AllocateNode::RawAddress);
3881   if (rawoop == NULL)  return NULL;
3882   for (DUIterator_Fast imax, i = rawoop->fast_outs(imax); i < imax; i++) {
3883     Node* init = rawoop->fast_out(i);
3884     if (init->is_Initialize()) {
3885       assert(init->as_Initialize()->allocation() == this, "2-way link");
3886       return init->as_Initialize();
3887     }
3888   }
3889   return NULL;
3890 }
3891 
3892 //----------------------------- loop predicates ---------------------------
3893 
3894 //------------------------------add_predicate_impl----------------------------
3895 void GraphKit::add_predicate_impl(Deoptimization::DeoptReason reason, int nargs) {
3896   // Too many traps seen?
3897   if (too_many_traps(reason)) {
3898 #ifdef ASSERT
3899     if (TraceLoopPredicate) {
3900       int tc = C->trap_count(reason);
3901       tty->print("too many traps=%s tcount=%d in ",
3902                     Deoptimization::trap_reason_name(reason), tc);
3903       method()->print(); // which method has too many predicate traps
3904       tty->cr();
3905     }
3906 #endif
3907     // We cannot afford to take more traps here,
3908     // do not generate predicate.
3909     return;
3910   }
3911 
3912   Node *cont    = _gvn.intcon(1);
3913   Node* opq     = _gvn.transform(new Opaque1Node(C, cont));
3914   Node *bol     = _gvn.transform(new Conv2BNode(opq));
3915   IfNode* iff   = create_and_map_if(control(), bol, PROB_MAX, COUNT_UNKNOWN);
3916   Node* iffalse = _gvn.transform(new IfFalseNode(iff));
3917   C->add_predicate_opaq(opq);
3918   {
3919     PreserveJVMState pjvms(this);
3920     set_control(iffalse);
3921     inc_sp(nargs);
3922     uncommon_trap(reason, Deoptimization::Action_maybe_recompile);
3923   }
3924   Node* iftrue = _gvn.transform(new IfTrueNode(iff));
3925   set_control(iftrue);
3926 }
3927 
3928 //------------------------------add_predicate---------------------------------
3929 void GraphKit::add_predicate(int nargs) {
3930   if (UseLoopPredicate) {
3931     add_predicate_impl(Deoptimization::Reason_predicate, nargs);
3932   }
3933   if (UseProfiledLoopPredicate) {
3934     add_predicate_impl(Deoptimization::Reason_profile_predicate, nargs);
3935   }
3936   // loop's limit check predicate should be near the loop.
3937   add_predicate_impl(Deoptimization::Reason_loop_limit_check, nargs);
3938 }
3939 
3940 void GraphKit::sync_kit(IdealKit& ideal) {
3941   set_all_memory(ideal.merged_memory());
3942   set_i_o(ideal.i_o());
3943   set_control(ideal.ctrl());
3944 }
3945 
3946 void GraphKit::final_sync(IdealKit& ideal) {
3947   // Final sync IdealKit and graphKit.
3948   sync_kit(ideal);
3949 }
3950 
3951 Node* GraphKit::load_String_length(Node* str, bool set_ctrl) {
3952   Node* len = load_array_length(load_String_value(str, set_ctrl));
3953   Node* coder = load_String_coder(str, set_ctrl);
3954   // Divide length by 2 if coder is UTF16
3955   return _gvn.transform(new RShiftINode(len, coder));
3956 }
3957 
3958 Node* GraphKit::load_String_value(Node* str, bool set_ctrl) {
3959   int value_offset = java_lang_String::value_offset_in_bytes();
3960   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
3961                                                      false, NULL, 0);
3962   const TypePtr* value_field_type = string_type->add_offset(value_offset);
3963   const TypeAryPtr* value_type = TypeAryPtr::make(TypePtr::NotNull,
3964                                                   TypeAry::make(TypeInt::BYTE, TypeInt::POS),
3965                                                   ciTypeArrayKlass::make(T_BYTE), true, 0);
3966   Node* p = basic_plus_adr(str, str, value_offset);
3967   Node* load = access_load_at(str, p, value_field_type, value_type, T_OBJECT,
3968                               IN_HEAP | (set_ctrl ? C2_CONTROL_DEPENDENT_LOAD : 0) | MO_UNORDERED);
3969   return load;
3970 }
3971 
3972 Node* GraphKit::load_String_coder(Node* str, bool set_ctrl) {
3973   if (!CompactStrings) {
3974     return intcon(java_lang_String::CODER_UTF16);
3975   }
3976   int coder_offset = java_lang_String::coder_offset_in_bytes();
3977   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
3978                                                      false, NULL, 0);
3979   const TypePtr* coder_field_type = string_type->add_offset(coder_offset);
3980 
3981   Node* p = basic_plus_adr(str, str, coder_offset);
3982   Node* load = access_load_at(str, p, coder_field_type, TypeInt::BYTE, T_BYTE,
3983                               IN_HEAP | (set_ctrl ? C2_CONTROL_DEPENDENT_LOAD : 0) | MO_UNORDERED);
3984   return load;
3985 }
3986 
3987 void GraphKit::store_String_value(Node* str, Node* value) {
3988   int value_offset = java_lang_String::value_offset_in_bytes();
3989   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
3990                                                      false, NULL, 0);
3991   const TypePtr* value_field_type = string_type->add_offset(value_offset);
3992 
3993   access_store_at(str,  basic_plus_adr(str, value_offset), value_field_type,
3994                   value, TypeAryPtr::BYTES, T_OBJECT, IN_HEAP | MO_UNORDERED);
3995 }
3996 
3997 void GraphKit::store_String_coder(Node* str, Node* value) {
3998   int coder_offset = java_lang_String::coder_offset_in_bytes();
3999   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4000                                                      false, NULL, 0);
4001   const TypePtr* coder_field_type = string_type->add_offset(coder_offset);
4002 
4003   access_store_at(str, basic_plus_adr(str, coder_offset), coder_field_type,
4004                   value, TypeInt::BYTE, T_BYTE, IN_HEAP | MO_UNORDERED);
4005 }
4006 
4007 // Capture src and dst memory state with a MergeMemNode
4008 Node* GraphKit::capture_memory(const TypePtr* src_type, const TypePtr* dst_type) {
4009   if (src_type == dst_type) {
4010     // Types are equal, we don't need a MergeMemNode
4011     return memory(src_type);
4012   }
4013   MergeMemNode* merge = MergeMemNode::make(map()->memory());
4014   record_for_igvn(merge); // fold it up later, if possible
4015   int src_idx = C->get_alias_index(src_type);
4016   int dst_idx = C->get_alias_index(dst_type);
4017   merge->set_memory_at(src_idx, memory(src_idx));
4018   merge->set_memory_at(dst_idx, memory(dst_idx));
4019   return merge;
4020 }
4021 
4022 Node* GraphKit::compress_string(Node* src, const TypeAryPtr* src_type, Node* dst, Node* count) {
4023   assert(Matcher::match_rule_supported(Op_StrCompressedCopy), "Intrinsic not supported");
4024   assert(src_type == TypeAryPtr::BYTES || src_type == TypeAryPtr::CHARS, "invalid source type");
4025   // If input and output memory types differ, capture both states to preserve
4026   // the dependency between preceding and subsequent loads/stores.
4027   // For example, the following program:
4028   //  StoreB
4029   //  compress_string
4030   //  LoadB
4031   // has this memory graph (use->def):
4032   //  LoadB -> compress_string -> CharMem
4033   //             ... -> StoreB -> ByteMem
4034   // The intrinsic hides the dependency between LoadB and StoreB, causing
4035   // the load to read from memory not containing the result of the StoreB.
4036   // The correct memory graph should look like this:
4037   //  LoadB -> compress_string -> MergeMem(CharMem, StoreB(ByteMem))
4038   Node* mem = capture_memory(src_type, TypeAryPtr::BYTES);
4039   StrCompressedCopyNode* str = new StrCompressedCopyNode(control(), mem, src, dst, count);
4040   Node* res_mem = _gvn.transform(new SCMemProjNode(str));
4041   set_memory(res_mem, TypeAryPtr::BYTES);
4042   return str;
4043 }
4044 
4045 void GraphKit::inflate_string(Node* src, Node* dst, const TypeAryPtr* dst_type, Node* count) {
4046   assert(Matcher::match_rule_supported(Op_StrInflatedCopy), "Intrinsic not supported");
4047   assert(dst_type == TypeAryPtr::BYTES || dst_type == TypeAryPtr::CHARS, "invalid dest type");
4048   // Capture src and dst memory (see comment in 'compress_string').
4049   Node* mem = capture_memory(TypeAryPtr::BYTES, dst_type);
4050   StrInflatedCopyNode* str = new StrInflatedCopyNode(control(), mem, src, dst, count);
4051   set_memory(_gvn.transform(str), dst_type);
4052 }
4053 
4054 void GraphKit::inflate_string_slow(Node* src, Node* dst, Node* start, Node* count) {
4055   /**
4056    * int i_char = start;
4057    * for (int i_byte = 0; i_byte < count; i_byte++) {
4058    *   dst[i_char++] = (char)(src[i_byte] & 0xff);
4059    * }
4060    */
4061   src = access_resolve(src, ACCESS_READ);
4062   dst = access_resolve(dst, ACCESS_WRITE);
4063   add_predicate();
4064   RegionNode* head = new RegionNode(3);
4065   head->init_req(1, control());
4066   gvn().set_type(head, Type::CONTROL);
4067   record_for_igvn(head);
4068 
4069   Node* i_byte = new PhiNode(head, TypeInt::INT);
4070   i_byte->init_req(1, intcon(0));
4071   gvn().set_type(i_byte, TypeInt::INT);
4072   record_for_igvn(i_byte);
4073 
4074   Node* i_char = new PhiNode(head, TypeInt::INT);
4075   i_char->init_req(1, start);
4076   gvn().set_type(i_char, TypeInt::INT);
4077   record_for_igvn(i_char);
4078 
4079   Node* mem = PhiNode::make(head, memory(TypeAryPtr::BYTES), Type::MEMORY, TypeAryPtr::BYTES);
4080   gvn().set_type(mem, Type::MEMORY);
4081   record_for_igvn(mem);
4082   set_control(head);
4083   set_memory(mem, TypeAryPtr::BYTES);
4084   Node* ch = load_array_element(control(), src, i_byte, TypeAryPtr::BYTES);
4085   Node* st = store_to_memory(control(), array_element_address(dst, i_char, T_BYTE),
4086                              AndI(ch, intcon(0xff)), T_CHAR, TypeAryPtr::BYTES, MemNode::unordered,
4087                              false, false, true /* mismatched */);
4088 
4089   IfNode* iff = create_and_map_if(head, Bool(CmpI(i_byte, count), BoolTest::lt), PROB_FAIR, COUNT_UNKNOWN);
4090   head->init_req(2, IfTrue(iff));
4091   mem->init_req(2, st);
4092   i_byte->init_req(2, AddI(i_byte, intcon(1)));
4093   i_char->init_req(2, AddI(i_char, intcon(2)));
4094 
4095   set_control(IfFalse(iff));
4096   set_memory(st, TypeAryPtr::BYTES);
4097 }
4098 
4099 Node* GraphKit::make_constant_from_field(ciField* field, Node* obj) {
4100   if (!field->is_constant()) {
4101     return NULL; // Field not marked as constant.
4102   }
4103   ciInstance* holder = NULL;
4104   if (!field->is_static()) {
4105     ciObject* const_oop = obj->bottom_type()->is_oopptr()->const_oop();
4106     if (const_oop != NULL && const_oop->is_instance()) {
4107       holder = const_oop->as_instance();
4108     }
4109   }
4110   const Type* con_type = Type::make_constant_from_field(field, holder, field->layout_type(),
4111                                                         /*is_unsigned_load=*/false);
4112   if (con_type != NULL) {
4113     return makecon(con_type);
4114   }
4115   return NULL;
4116 }