1 /*
   2  * Copyright (c) 2001, 2014, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "compiler/compileLog.hpp"
  27 #include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp"
  28 #include "gc_implementation/g1/heapRegion.hpp"
  29 #include "gc_interface/collectedHeap.hpp"
  30 #include "memory/barrierSet.hpp"
  31 #include "memory/cardTableModRefBS.hpp"
  32 #include "opto/addnode.hpp"
  33 #include "opto/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 {
  54   _exceptions = jvms->map()->next_exception();
  55   if (_exceptions != NULL)  jvms->map()->set_next_exception(NULL);
  56   set_jvms(jvms);
  57 }
  58 
  59 // Private constructor for parser.
  60 GraphKit::GraphKit()
  61   : Phase(Phase::Parser),
  62     _env(C->env()),
  63     _gvn(*C->initial_gvn())
  64 {
  65   _exceptions = NULL;
  66   set_map(NULL);
  67   debug_only(_sp = -99);
  68   debug_only(set_bci(-99));
  69 }
  70 
  71 
  72 
  73 //---------------------------clean_stack---------------------------------------
  74 // Clear away rubbish from the stack area of the JVM state.
  75 // This destroys any arguments that may be waiting on the stack.
  76 void GraphKit::clean_stack(int from_sp) {
  77   SafePointNode* map      = this->map();
  78   JVMState*      jvms     = this->jvms();
  79   int            stk_size = jvms->stk_size();
  80   int            stkoff   = jvms->stkoff();
  81   Node*          top      = this->top();
  82   for (int i = from_sp; i < stk_size; i++) {
  83     if (map->in(stkoff + i) != top) {
  84       map->set_req(stkoff + i, top);
  85     }
  86   }
  87 }
  88 
  89 
  90 //--------------------------------sync_jvms-----------------------------------
  91 // Make sure our current jvms agrees with our parse state.
  92 JVMState* GraphKit::sync_jvms() const {
  93   JVMState* jvms = this->jvms();
  94   jvms->set_bci(bci());       // Record the new bci in the JVMState
  95   jvms->set_sp(sp());         // Record the new sp in the JVMState
  96   assert(jvms_in_sync(), "jvms is now in sync");
  97   return jvms;
  98 }
  99 
 100 //--------------------------------sync_jvms_for_reexecute---------------------
 101 // Make sure our current jvms agrees with our parse state.  This version
 102 // uses the reexecute_sp for reexecuting bytecodes.
 103 JVMState* GraphKit::sync_jvms_for_reexecute() {
 104   JVMState* jvms = this->jvms();
 105   jvms->set_bci(bci());          // Record the new bci in the JVMState
 106   jvms->set_sp(reexecute_sp());  // Record the new sp in the JVMState
 107   return jvms;
 108 }
 109 
 110 #ifdef ASSERT
 111 bool GraphKit::jvms_in_sync() const {
 112   Parse* parse = is_Parse();
 113   if (parse == NULL) {
 114     if (bci() !=      jvms()->bci())          return false;
 115     if (sp()  != (int)jvms()->sp())           return false;
 116     return true;
 117   }
 118   if (jvms()->method() != parse->method())    return false;
 119   if (jvms()->bci()    != parse->bci())       return false;
 120   int jvms_sp = jvms()->sp();
 121   if (jvms_sp          != parse->sp())        return false;
 122   int jvms_depth = jvms()->depth();
 123   if (jvms_depth       != parse->depth())     return false;
 124   return true;
 125 }
 126 
 127 // Local helper checks for special internal merge points
 128 // used to accumulate and merge exception states.
 129 // They are marked by the region's in(0) edge being the map itself.
 130 // Such merge points must never "escape" into the parser at large,
 131 // until they have been handed to gvn.transform.
 132 static bool is_hidden_merge(Node* reg) {
 133   if (reg == NULL)  return false;
 134   if (reg->is_Phi()) {
 135     reg = reg->in(0);
 136     if (reg == NULL)  return false;
 137   }
 138   return reg->is_Region() && reg->in(0) != NULL && reg->in(0)->is_Root();
 139 }
 140 
 141 void GraphKit::verify_map() const {
 142   if (map() == NULL)  return;  // null map is OK
 143   assert(map()->req() <= jvms()->endoff(), "no extra garbage on map");
 144   assert(!map()->has_exceptions(),    "call add_exception_states_from 1st");
 145   assert(!is_hidden_merge(control()), "call use_exception_state, not set_map");
 146 }
 147 
 148 void GraphKit::verify_exception_state(SafePointNode* ex_map) {
 149   assert(ex_map->next_exception() == NULL, "not already part of a chain");
 150   assert(has_saved_ex_oop(ex_map), "every exception state has an ex_oop");
 151 }
 152 #endif
 153 
 154 //---------------------------stop_and_kill_map---------------------------------
 155 // Set _map to NULL, signalling a stop to further bytecode execution.
 156 // First smash the current map's control to a constant, to mark it dead.
 157 void GraphKit::stop_and_kill_map() {
 158   SafePointNode* dead_map = stop();
 159   if (dead_map != NULL) {
 160     dead_map->disconnect_inputs(NULL, C); // Mark the map as killed.
 161     assert(dead_map->is_killed(), "must be so marked");
 162   }
 163 }
 164 
 165 
 166 //--------------------------------stopped--------------------------------------
 167 // Tell if _map is NULL, or control is top.
 168 bool GraphKit::stopped() {
 169   if (map() == NULL)           return true;
 170   else if (control() == top()) return true;
 171   else                         return false;
 172 }
 173 
 174 
 175 //-----------------------------has_ex_handler----------------------------------
 176 // Tell if this method or any caller method has exception handlers.
 177 bool GraphKit::has_ex_handler() {
 178   for (JVMState* jvmsp = jvms(); jvmsp != NULL; jvmsp = jvmsp->caller()) {
 179     if (jvmsp->has_method() && jvmsp->method()->has_exception_handlers()) {
 180       return true;
 181     }
 182   }
 183   return false;
 184 }
 185 
 186 //------------------------------save_ex_oop------------------------------------
 187 // Save an exception without blowing stack contents or other JVM state.
 188 void GraphKit::set_saved_ex_oop(SafePointNode* ex_map, Node* ex_oop) {
 189   assert(!has_saved_ex_oop(ex_map), "clear ex-oop before setting again");
 190   ex_map->add_req(ex_oop);
 191   debug_only(verify_exception_state(ex_map));
 192 }
 193 
 194 inline static Node* common_saved_ex_oop(SafePointNode* ex_map, bool clear_it) {
 195   assert(GraphKit::has_saved_ex_oop(ex_map), "ex_oop must be there");
 196   Node* ex_oop = ex_map->in(ex_map->req()-1);
 197   if (clear_it)  ex_map->del_req(ex_map->req()-1);
 198   return ex_oop;
 199 }
 200 
 201 //-----------------------------saved_ex_oop------------------------------------
 202 // Recover a saved exception from its map.
 203 Node* GraphKit::saved_ex_oop(SafePointNode* ex_map) {
 204   return common_saved_ex_oop(ex_map, false);
 205 }
 206 
 207 //--------------------------clear_saved_ex_oop---------------------------------
 208 // Erase a previously saved exception from its map.
 209 Node* GraphKit::clear_saved_ex_oop(SafePointNode* ex_map) {
 210   return common_saved_ex_oop(ex_map, true);
 211 }
 212 
 213 #ifdef ASSERT
 214 //---------------------------has_saved_ex_oop----------------------------------
 215 // Erase a previously saved exception from its map.
 216 bool GraphKit::has_saved_ex_oop(SafePointNode* ex_map) {
 217   return ex_map->req() == ex_map->jvms()->endoff()+1;
 218 }
 219 #endif
 220 
 221 //-------------------------make_exception_state--------------------------------
 222 // Turn the current JVM state into an exception state, appending the ex_oop.
 223 SafePointNode* GraphKit::make_exception_state(Node* ex_oop) {
 224   sync_jvms();
 225   SafePointNode* ex_map = stop();  // do not manipulate this map any more
 226   set_saved_ex_oop(ex_map, ex_oop);
 227   return ex_map;
 228 }
 229 
 230 
 231 //--------------------------add_exception_state--------------------------------
 232 // Add an exception to my list of exceptions.
 233 void GraphKit::add_exception_state(SafePointNode* ex_map) {
 234   if (ex_map == NULL || ex_map->control() == top()) {
 235     return;
 236   }
 237 #ifdef ASSERT
 238   verify_exception_state(ex_map);
 239   if (has_exceptions()) {
 240     assert(ex_map->jvms()->same_calls_as(_exceptions->jvms()), "all collected exceptions must come from the same place");
 241   }
 242 #endif
 243 
 244   // If there is already an exception of exactly this type, merge with it.
 245   // In particular, null-checks and other low-level exceptions common up here.
 246   Node*       ex_oop  = saved_ex_oop(ex_map);
 247   const Type* ex_type = _gvn.type(ex_oop);
 248   if (ex_oop == top()) {
 249     // No action needed.
 250     return;
 251   }
 252   assert(ex_type->isa_instptr(), "exception must be an instance");
 253   for (SafePointNode* e2 = _exceptions; e2 != NULL; e2 = e2->next_exception()) {
 254     const Type* ex_type2 = _gvn.type(saved_ex_oop(e2));
 255     // We check sp also because call bytecodes can generate exceptions
 256     // both before and after arguments are popped!
 257     if (ex_type2 == ex_type
 258         && e2->_jvms->sp() == ex_map->_jvms->sp()) {
 259       combine_exception_states(ex_map, e2);
 260       return;
 261     }
 262   }
 263 
 264   // No pre-existing exception of the same type.  Chain it on the list.
 265   push_exception_state(ex_map);
 266 }
 267 
 268 //-----------------------add_exception_states_from-----------------------------
 269 void GraphKit::add_exception_states_from(JVMState* jvms) {
 270   SafePointNode* ex_map = jvms->map()->next_exception();
 271   if (ex_map != NULL) {
 272     jvms->map()->set_next_exception(NULL);
 273     for (SafePointNode* next_map; ex_map != NULL; ex_map = next_map) {
 274       next_map = ex_map->next_exception();
 275       ex_map->set_next_exception(NULL);
 276       add_exception_state(ex_map);
 277     }
 278   }
 279 }
 280 
 281 //-----------------------transfer_exceptions_into_jvms-------------------------
 282 JVMState* GraphKit::transfer_exceptions_into_jvms() {
 283   if (map() == NULL) {
 284     // We need a JVMS to carry the exceptions, but the map has gone away.
 285     // Create a scratch JVMS, cloned from any of the exception states...
 286     if (has_exceptions()) {
 287       _map = _exceptions;
 288       _map = clone_map();
 289       _map->set_next_exception(NULL);
 290       clear_saved_ex_oop(_map);
 291       debug_only(verify_map());
 292     } else {
 293       // ...or created from scratch
 294       JVMState* jvms = new (C) JVMState(_method, NULL);
 295       jvms->set_bci(_bci);
 296       jvms->set_sp(_sp);
 297       jvms->set_map(new SafePointNode(TypeFunc::Parms, jvms));
 298       set_jvms(jvms);
 299       for (uint i = 0; i < map()->req(); i++)  map()->init_req(i, top());
 300       set_all_memory(top());
 301       while (map()->req() < jvms->endoff())  map()->add_req(top());
 302     }
 303     // (This is a kludge, in case you didn't notice.)
 304     set_control(top());
 305   }
 306   JVMState* jvms = sync_jvms();
 307   assert(!jvms->map()->has_exceptions(), "no exceptions on this map yet");
 308   jvms->map()->set_next_exception(_exceptions);
 309   _exceptions = NULL;   // done with this set of exceptions
 310   return jvms;
 311 }
 312 
 313 static inline void add_n_reqs(Node* dstphi, Node* srcphi) {
 314   assert(is_hidden_merge(dstphi), "must be a special merge node");
 315   assert(is_hidden_merge(srcphi), "must be a special merge node");
 316   uint limit = srcphi->req();
 317   for (uint i = PhiNode::Input; i < limit; i++) {
 318     dstphi->add_req(srcphi->in(i));
 319   }
 320 }
 321 static inline void add_one_req(Node* dstphi, Node* src) {
 322   assert(is_hidden_merge(dstphi), "must be a special merge node");
 323   assert(!is_hidden_merge(src), "must not be a special merge node");
 324   dstphi->add_req(src);
 325 }
 326 
 327 //-----------------------combine_exception_states------------------------------
 328 // This helper function combines exception states by building phis on a
 329 // specially marked state-merging region.  These regions and phis are
 330 // untransformed, and can build up gradually.  The region is marked by
 331 // having a control input of its exception map, rather than NULL.  Such
 332 // regions do not appear except in this function, and in use_exception_state.
 333 void GraphKit::combine_exception_states(SafePointNode* ex_map, SafePointNode* phi_map) {
 334   if (failing())  return;  // dying anyway...
 335   JVMState* ex_jvms = ex_map->_jvms;
 336   assert(ex_jvms->same_calls_as(phi_map->_jvms), "consistent call chains");
 337   assert(ex_jvms->stkoff() == phi_map->_jvms->stkoff(), "matching locals");
 338   assert(ex_jvms->sp() == phi_map->_jvms->sp(), "matching stack sizes");
 339   assert(ex_jvms->monoff() == phi_map->_jvms->monoff(), "matching JVMS");
 340   assert(ex_jvms->scloff() == phi_map->_jvms->scloff(), "matching scalar replaced objects");
 341   assert(ex_map->req() == phi_map->req(), "matching maps");
 342   uint tos = ex_jvms->stkoff() + ex_jvms->sp();
 343   Node*         hidden_merge_mark = root();
 344   Node*         region  = phi_map->control();
 345   MergeMemNode* phi_mem = phi_map->merged_memory();
 346   MergeMemNode* ex_mem  = ex_map->merged_memory();
 347   if (region->in(0) != hidden_merge_mark) {
 348     // The control input is not (yet) a specially-marked region in phi_map.
 349     // Make it so, and build some phis.
 350     region = new RegionNode(2);
 351     _gvn.set_type(region, Type::CONTROL);
 352     region->set_req(0, hidden_merge_mark);  // marks an internal ex-state
 353     region->init_req(1, phi_map->control());
 354     phi_map->set_control(region);
 355     Node* io_phi = PhiNode::make(region, phi_map->i_o(), Type::ABIO);
 356     record_for_igvn(io_phi);
 357     _gvn.set_type(io_phi, Type::ABIO);
 358     phi_map->set_i_o(io_phi);
 359     for (MergeMemStream mms(phi_mem); mms.next_non_empty(); ) {
 360       Node* m = mms.memory();
 361       Node* m_phi = PhiNode::make(region, m, Type::MEMORY, mms.adr_type(C));
 362       record_for_igvn(m_phi);
 363       _gvn.set_type(m_phi, Type::MEMORY);
 364       mms.set_memory(m_phi);
 365     }
 366   }
 367 
 368   // Either or both of phi_map and ex_map might already be converted into phis.
 369   Node* ex_control = ex_map->control();
 370   // if there is special marking on ex_map also, we add multiple edges from src
 371   bool add_multiple = (ex_control->in(0) == hidden_merge_mark);
 372   // how wide was the destination phi_map, originally?
 373   uint orig_width = region->req();
 374 
 375   if (add_multiple) {
 376     add_n_reqs(region, ex_control);
 377     add_n_reqs(phi_map->i_o(), ex_map->i_o());
 378   } else {
 379     // ex_map has no merges, so we just add single edges everywhere
 380     add_one_req(region, ex_control);
 381     add_one_req(phi_map->i_o(), ex_map->i_o());
 382   }
 383   for (MergeMemStream mms(phi_mem, ex_mem); mms.next_non_empty2(); ) {
 384     if (mms.is_empty()) {
 385       // get a copy of the base memory, and patch some inputs into it
 386       const TypePtr* adr_type = mms.adr_type(C);
 387       Node* phi = mms.force_memory()->as_Phi()->slice_memory(adr_type);
 388       assert(phi->as_Phi()->region() == mms.base_memory()->in(0), "");
 389       mms.set_memory(phi);
 390       // Prepare to append interesting stuff onto the newly sliced phi:
 391       while (phi->req() > orig_width)  phi->del_req(phi->req()-1);
 392     }
 393     // Append stuff from ex_map:
 394     if (add_multiple) {
 395       add_n_reqs(mms.memory(), mms.memory2());
 396     } else {
 397       add_one_req(mms.memory(), mms.memory2());
 398     }
 399   }
 400   uint limit = ex_map->req();
 401   for (uint i = TypeFunc::Parms; i < limit; i++) {
 402     // Skip everything in the JVMS after tos.  (The ex_oop follows.)
 403     if (i == tos)  i = ex_jvms->monoff();
 404     Node* src = ex_map->in(i);
 405     Node* dst = phi_map->in(i);
 406     if (src != dst) {
 407       PhiNode* phi;
 408       if (dst->in(0) != region) {
 409         dst = phi = PhiNode::make(region, dst, _gvn.type(dst));
 410         record_for_igvn(phi);
 411         _gvn.set_type(phi, phi->type());
 412         phi_map->set_req(i, dst);
 413         // Prepare to append interesting stuff onto the new phi:
 414         while (dst->req() > orig_width)  dst->del_req(dst->req()-1);
 415       } else {
 416         assert(dst->is_Phi(), "nobody else uses a hidden region");
 417         phi = dst->as_Phi();
 418       }
 419       if (add_multiple && src->in(0) == ex_control) {
 420         // Both are phis.
 421         add_n_reqs(dst, src);
 422       } else {
 423         while (dst->req() < region->req())  add_one_req(dst, src);
 424       }
 425       const Type* srctype = _gvn.type(src);
 426       if (phi->type() != srctype) {
 427         const Type* dsttype = phi->type()->meet_speculative(srctype);
 428         if (phi->type() != dsttype) {
 429           phi->set_type(dsttype);
 430           _gvn.set_type(phi, dsttype);
 431         }
 432       }
 433     }
 434   }
 435   phi_map->merge_replaced_nodes_with(ex_map);
 436 }
 437 
 438 //--------------------------use_exception_state--------------------------------
 439 Node* GraphKit::use_exception_state(SafePointNode* phi_map) {
 440   if (failing()) { stop(); return top(); }
 441   Node* region = phi_map->control();
 442   Node* hidden_merge_mark = root();
 443   assert(phi_map->jvms()->map() == phi_map, "sanity: 1-1 relation");
 444   Node* ex_oop = clear_saved_ex_oop(phi_map);
 445   if (region->in(0) == hidden_merge_mark) {
 446     // Special marking for internal ex-states.  Process the phis now.
 447     region->set_req(0, region);  // now it's an ordinary region
 448     set_jvms(phi_map->jvms());   // ...so now we can use it as a map
 449     // Note: Setting the jvms also sets the bci and sp.
 450     set_control(_gvn.transform(region));
 451     uint tos = jvms()->stkoff() + sp();
 452     for (uint i = 1; i < tos; i++) {
 453       Node* x = phi_map->in(i);
 454       if (x->in(0) == region) {
 455         assert(x->is_Phi(), "expected a special phi");
 456         phi_map->set_req(i, _gvn.transform(x));
 457       }
 458     }
 459     for (MergeMemStream mms(merged_memory()); mms.next_non_empty(); ) {
 460       Node* x = mms.memory();
 461       if (x->in(0) == region) {
 462         assert(x->is_Phi(), "nobody else uses a hidden region");
 463         mms.set_memory(_gvn.transform(x));
 464       }
 465     }
 466     if (ex_oop->in(0) == region) {
 467       assert(ex_oop->is_Phi(), "expected a special phi");
 468       ex_oop = _gvn.transform(ex_oop);
 469     }
 470   } else {
 471     set_jvms(phi_map->jvms());
 472   }
 473 
 474   assert(!is_hidden_merge(phi_map->control()), "hidden ex. states cleared");
 475   assert(!is_hidden_merge(phi_map->i_o()), "hidden ex. states cleared");
 476   return ex_oop;
 477 }
 478 
 479 //---------------------------------java_bc-------------------------------------
 480 Bytecodes::Code GraphKit::java_bc() const {
 481   ciMethod* method = this->method();
 482   int       bci    = this->bci();
 483   if (method != NULL && bci != InvocationEntryBci)
 484     return method->java_code_at_bci(bci);
 485   else
 486     return Bytecodes::_illegal;
 487 }
 488 
 489 void GraphKit::uncommon_trap_if_should_post_on_exceptions(Deoptimization::DeoptReason reason,
 490                                                           bool must_throw) {
 491     // if the exception capability is set, then we will generate code
 492     // to check the JavaThread.should_post_on_exceptions flag to see
 493     // if we actually need to report exception events (for this
 494     // thread).  If we don't need to report exception events, we will
 495     // take the normal fast path provided by add_exception_events.  If
 496     // exception event reporting is enabled for this thread, we will
 497     // take the uncommon_trap in the BuildCutout below.
 498 
 499     // first must access the should_post_on_exceptions_flag in this thread's JavaThread
 500     Node* jthread = _gvn.transform(new ThreadLocalNode());
 501     Node* adr = basic_plus_adr(top(), jthread, in_bytes(JavaThread::should_post_on_exceptions_flag_offset()));
 502     Node* should_post_flag = make_load(control(), adr, TypeInt::INT, T_INT, Compile::AliasIdxRaw, MemNode::unordered);
 503 
 504     // Test the should_post_on_exceptions_flag vs. 0
 505     Node* chk = _gvn.transform( new CmpINode(should_post_flag, intcon(0)) );
 506     Node* tst = _gvn.transform( new BoolNode(chk, BoolTest::eq) );
 507 
 508     // Branch to slow_path if should_post_on_exceptions_flag was true
 509     { BuildCutout unless(this, tst, PROB_MAX);
 510       // Do not try anything fancy if we're notifying the VM on every throw.
 511       // Cf. case Bytecodes::_athrow in parse2.cpp.
 512       uncommon_trap(reason, Deoptimization::Action_none,
 513                     (ciKlass*)NULL, (char*)NULL, must_throw);
 514     }
 515 
 516 }
 517 
 518 //------------------------------builtin_throw----------------------------------
 519 void GraphKit::builtin_throw(Deoptimization::DeoptReason reason, Node* arg) {
 520   bool must_throw = true;
 521 
 522   if (env()->jvmti_can_post_on_exceptions()) {
 523     // check if we must post exception events, take uncommon trap if so
 524     uncommon_trap_if_should_post_on_exceptions(reason, must_throw);
 525     // here if should_post_on_exceptions is false
 526     // continue on with the normal codegen
 527   }
 528 
 529   // If this particular condition has not yet happened at this
 530   // bytecode, then use the uncommon trap mechanism, and allow for
 531   // a future recompilation if several traps occur here.
 532   // If the throw is hot, try to use a more complicated inline mechanism
 533   // which keeps execution inside the compiled code.
 534   bool treat_throw_as_hot = false;
 535   ciMethodData* md = method()->method_data();
 536 
 537   if (ProfileTraps) {
 538     if (too_many_traps(reason)) {
 539       treat_throw_as_hot = true;
 540     }
 541     // (If there is no MDO at all, assume it is early in
 542     // execution, and that any deopts are part of the
 543     // startup transient, and don't need to be remembered.)
 544 
 545     // Also, if there is a local exception handler, treat all throws
 546     // as hot if there has been at least one in this method.
 547     if (C->trap_count(reason) != 0
 548         && method()->method_data()->trap_count(reason) != 0
 549         && has_ex_handler()) {
 550         treat_throw_as_hot = true;
 551     }
 552   }
 553 
 554   // If this throw happens frequently, an uncommon trap might cause
 555   // a performance pothole.  If there is a local exception handler,
 556   // and if this particular bytecode appears to be deoptimizing often,
 557   // let us handle the throw inline, with a preconstructed instance.
 558   // Note:   If the deopt count has blown up, the uncommon trap
 559   // runtime is going to flush this nmethod, not matter what.
 560   if (treat_throw_as_hot
 561       && (!StackTraceInThrowable || OmitStackTraceInFastThrow)) {
 562     // If the throw is local, we use a pre-existing instance and
 563     // punt on the backtrace.  This would lead to a missing backtrace
 564     // (a repeat of 4292742) if the backtrace object is ever asked
 565     // for its backtrace.
 566     // Fixing this remaining case of 4292742 requires some flavor of
 567     // escape analysis.  Leave that for the future.
 568     ciInstance* ex_obj = NULL;
 569     switch (reason) {
 570     case Deoptimization::Reason_null_check:
 571       ex_obj = env()->NullPointerException_instance();
 572       break;
 573     case Deoptimization::Reason_div0_check:
 574       ex_obj = env()->ArithmeticException_instance();
 575       break;
 576     case Deoptimization::Reason_range_check:
 577       ex_obj = env()->ArrayIndexOutOfBoundsException_instance();
 578       break;
 579     case Deoptimization::Reason_class_check:
 580       if (java_bc() == Bytecodes::_aastore) {
 581         ex_obj = env()->ArrayStoreException_instance();
 582       } else {
 583         ex_obj = env()->ClassCastException_instance();
 584       }
 585       break;
 586     }
 587     if (failing()) { stop(); return; }  // exception allocation might fail
 588     if (ex_obj != NULL) {
 589       // Cheat with a preallocated exception object.
 590       if (C->log() != NULL)
 591         C->log()->elem("hot_throw preallocated='1' reason='%s'",
 592                        Deoptimization::trap_reason_name(reason));
 593       const TypeInstPtr* ex_con  = TypeInstPtr::make(ex_obj);
 594       Node*              ex_node = _gvn.transform(ConNode::make(ex_con));
 595 
 596       // Clear the detail message of the preallocated exception object.
 597       // Weblogic sometimes mutates the detail message of exceptions
 598       // using reflection.
 599       int offset = java_lang_Throwable::get_detailMessage_offset();
 600       const TypePtr* adr_typ = ex_con->add_offset(offset);
 601 
 602       Node *adr = basic_plus_adr(ex_node, ex_node, offset);
 603       const TypeOopPtr* val_type = TypeOopPtr::make_from_klass(env()->String_klass());
 604       // Conservatively release stores of object references.
 605       Node *store = store_oop_to_object(control(), ex_node, adr, adr_typ, null(), val_type, T_OBJECT, MemNode::release);
 606 
 607       add_exception_state(make_exception_state(ex_node));
 608       return;
 609     }
 610   }
 611 
 612   // %%% Maybe add entry to OptoRuntime which directly throws the exc.?
 613   // It won't be much cheaper than bailing to the interp., since we'll
 614   // have to pass up all the debug-info, and the runtime will have to
 615   // create the stack trace.
 616 
 617   // Usual case:  Bail to interpreter.
 618   // Reserve the right to recompile if we haven't seen anything yet.
 619 
 620   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? C->method() : NULL;
 621   Deoptimization::DeoptAction action = Deoptimization::Action_maybe_recompile;
 622   if (treat_throw_as_hot
 623       && (method()->method_data()->trap_recompiled_at(bci(), m)
 624           || C->too_many_traps(reason))) {
 625     // We cannot afford to take more traps here.  Suffer in the interpreter.
 626     if (C->log() != NULL)
 627       C->log()->elem("hot_throw preallocated='0' reason='%s' mcount='%d'",
 628                      Deoptimization::trap_reason_name(reason),
 629                      C->trap_count(reason));
 630     action = Deoptimization::Action_none;
 631   }
 632 
 633   // "must_throw" prunes the JVM state to include only the stack, if there
 634   // are no local exception handlers.  This should cut down on register
 635   // allocation time and code size, by drastically reducing the number
 636   // of in-edges on the call to the uncommon trap.
 637 
 638   uncommon_trap(reason, action, (ciKlass*)NULL, (char*)NULL, must_throw);
 639 }
 640 
 641 
 642 //----------------------------PreserveJVMState---------------------------------
 643 PreserveJVMState::PreserveJVMState(GraphKit* kit, bool clone_map) {
 644   debug_only(kit->verify_map());
 645   _kit    = kit;
 646   _map    = kit->map();   // preserve the map
 647   _sp     = kit->sp();
 648   kit->set_map(clone_map ? kit->clone_map() : NULL);
 649 #ifdef ASSERT
 650   _bci    = kit->bci();
 651   Parse* parser = kit->is_Parse();
 652   int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo();
 653   _block  = block;
 654 #endif
 655 }
 656 PreserveJVMState::~PreserveJVMState() {
 657   GraphKit* kit = _kit;
 658 #ifdef ASSERT
 659   assert(kit->bci() == _bci, "bci must not shift");
 660   Parse* parser = kit->is_Parse();
 661   int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo();
 662   assert(block == _block,    "block must not shift");
 663 #endif
 664   kit->set_map(_map);
 665   kit->set_sp(_sp);
 666 }
 667 
 668 
 669 //-----------------------------BuildCutout-------------------------------------
 670 BuildCutout::BuildCutout(GraphKit* kit, Node* p, float prob, float cnt)
 671   : PreserveJVMState(kit)
 672 {
 673   assert(p->is_Con() || p->is_Bool(), "test must be a bool");
 674   SafePointNode* outer_map = _map;   // preserved map is caller's
 675   SafePointNode* inner_map = kit->map();
 676   IfNode* iff = kit->create_and_map_if(outer_map->control(), p, prob, cnt);
 677   outer_map->set_control(kit->gvn().transform( new IfTrueNode(iff) ));
 678   inner_map->set_control(kit->gvn().transform( new IfFalseNode(iff) ));
 679 }
 680 BuildCutout::~BuildCutout() {
 681   GraphKit* kit = _kit;
 682   assert(kit->stopped(), "cutout code must stop, throw, return, etc.");
 683 }
 684 
 685 //---------------------------PreserveReexecuteState----------------------------
 686 PreserveReexecuteState::PreserveReexecuteState(GraphKit* kit) {
 687   assert(!kit->stopped(), "must call stopped() before");
 688   _kit    =    kit;
 689   _sp     =    kit->sp();
 690   _reexecute = kit->jvms()->_reexecute;
 691 }
 692 PreserveReexecuteState::~PreserveReexecuteState() {
 693   if (_kit->stopped()) return;
 694   _kit->jvms()->_reexecute = _reexecute;
 695   _kit->set_sp(_sp);
 696 }
 697 
 698 //------------------------------clone_map--------------------------------------
 699 // Implementation of PreserveJVMState
 700 //
 701 // Only clone_map(...) here. If this function is only used in the
 702 // PreserveJVMState class we may want to get rid of this extra
 703 // function eventually and do it all there.
 704 
 705 SafePointNode* GraphKit::clone_map() {
 706   if (map() == NULL)  return NULL;
 707 
 708   // Clone the memory edge first
 709   Node* mem = MergeMemNode::make(map()->memory());
 710   gvn().set_type_bottom(mem);
 711 
 712   SafePointNode *clonemap = (SafePointNode*)map()->clone();
 713   JVMState* jvms = this->jvms();
 714   JVMState* clonejvms = jvms->clone_shallow(C);
 715   clonemap->set_memory(mem);
 716   clonemap->set_jvms(clonejvms);
 717   clonejvms->set_map(clonemap);
 718   record_for_igvn(clonemap);
 719   gvn().set_type_bottom(clonemap);
 720   return clonemap;
 721 }
 722 
 723 
 724 //-----------------------------set_map_clone-----------------------------------
 725 void GraphKit::set_map_clone(SafePointNode* m) {
 726   _map = m;
 727   _map = clone_map();
 728   _map->set_next_exception(NULL);
 729   debug_only(verify_map());
 730 }
 731 
 732 
 733 //----------------------------kill_dead_locals---------------------------------
 734 // Detect any locals which are known to be dead, and force them to top.
 735 void GraphKit::kill_dead_locals() {
 736   // Consult the liveness information for the locals.  If any
 737   // of them are unused, then they can be replaced by top().  This
 738   // should help register allocation time and cut down on the size
 739   // of the deoptimization information.
 740 
 741   // This call is made from many of the bytecode handling
 742   // subroutines called from the Big Switch in do_one_bytecode.
 743   // Every bytecode which might include a slow path is responsible
 744   // for killing its dead locals.  The more consistent we
 745   // are about killing deads, the fewer useless phis will be
 746   // constructed for them at various merge points.
 747 
 748   // bci can be -1 (InvocationEntryBci).  We return the entry
 749   // liveness for the method.
 750 
 751   if (method() == NULL || method()->code_size() == 0) {
 752     // We are building a graph for a call to a native method.
 753     // All locals are live.
 754     return;
 755   }
 756 
 757   ResourceMark rm;
 758 
 759   // Consult the liveness information for the locals.  If any
 760   // of them are unused, then they can be replaced by top().  This
 761   // should help register allocation time and cut down on the size
 762   // of the deoptimization information.
 763   MethodLivenessResult live_locals = method()->liveness_at_bci(bci());
 764 
 765   int len = (int)live_locals.size();
 766   assert(len <= jvms()->loc_size(), "too many live locals");
 767   for (int local = 0; local < len; local++) {
 768     if (!live_locals.at(local)) {
 769       set_local(local, top());
 770     }
 771   }
 772 }
 773 
 774 #ifdef ASSERT
 775 //-------------------------dead_locals_are_killed------------------------------
 776 // Return true if all dead locals are set to top in the map.
 777 // Used to assert "clean" debug info at various points.
 778 bool GraphKit::dead_locals_are_killed() {
 779   if (method() == NULL || method()->code_size() == 0) {
 780     // No locals need to be dead, so all is as it should be.
 781     return true;
 782   }
 783 
 784   // Make sure somebody called kill_dead_locals upstream.
 785   ResourceMark rm;
 786   for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) {
 787     if (jvms->loc_size() == 0)  continue;  // no locals to consult
 788     SafePointNode* map = jvms->map();
 789     ciMethod* method = jvms->method();
 790     int       bci    = jvms->bci();
 791     if (jvms == this->jvms()) {
 792       bci = this->bci();  // it might not yet be synched
 793     }
 794     MethodLivenessResult live_locals = method->liveness_at_bci(bci);
 795     int len = (int)live_locals.size();
 796     if (!live_locals.is_valid() || len == 0)
 797       // This method is trivial, or is poisoned by a breakpoint.
 798       return true;
 799     assert(len == jvms->loc_size(), "live map consistent with locals map");
 800     for (int local = 0; local < len; local++) {
 801       if (!live_locals.at(local) && map->local(jvms, local) != top()) {
 802         if (PrintMiscellaneous && (Verbose || WizardMode)) {
 803           tty->print_cr("Zombie local %d: ", local);
 804           jvms->dump();
 805         }
 806         return false;
 807       }
 808     }
 809   }
 810   return true;
 811 }
 812 
 813 #endif //ASSERT
 814 
 815 // Helper function for enforcing certain bytecodes to reexecute if
 816 // deoptimization happens
 817 static bool should_reexecute_implied_by_bytecode(JVMState *jvms, bool is_anewarray) {
 818   ciMethod* cur_method = jvms->method();
 819   int       cur_bci   = jvms->bci();
 820   if (cur_method != NULL && cur_bci != InvocationEntryBci) {
 821     Bytecodes::Code code = cur_method->java_code_at_bci(cur_bci);
 822     return Interpreter::bytecode_should_reexecute(code) ||
 823            is_anewarray && code == Bytecodes::_multianewarray;
 824     // Reexecute _multianewarray bytecode which was replaced with
 825     // sequence of [a]newarray. See Parse::do_multianewarray().
 826     //
 827     // Note: interpreter should not have it set since this optimization
 828     // is limited by dimensions and guarded by flag so in some cases
 829     // multianewarray() runtime calls will be generated and
 830     // the bytecode should not be reexecutes (stack will not be reset).
 831   } else
 832     return false;
 833 }
 834 
 835 // Helper function for adding JVMState and debug information to node
 836 void GraphKit::add_safepoint_edges(SafePointNode* call, bool must_throw) {
 837   // Add the safepoint edges to the call (or other safepoint).
 838 
 839   // Make sure dead locals are set to top.  This
 840   // should help register allocation time and cut down on the size
 841   // of the deoptimization information.
 842   assert(dead_locals_are_killed(), "garbage in debug info before safepoint");
 843 
 844   // Walk the inline list to fill in the correct set of JVMState's
 845   // Also fill in the associated edges for each JVMState.
 846 
 847   // If the bytecode needs to be reexecuted we need to put
 848   // the arguments back on the stack.
 849   const bool should_reexecute = jvms()->should_reexecute();
 850   JVMState* youngest_jvms = should_reexecute ? sync_jvms_for_reexecute() : sync_jvms();
 851 
 852   // NOTE: set_bci (called from sync_jvms) might reset the reexecute bit to
 853   // undefined if the bci is different.  This is normal for Parse but it
 854   // should not happen for LibraryCallKit because only one bci is processed.
 855   assert(!is_LibraryCallKit() || (jvms()->should_reexecute() == should_reexecute),
 856          "in LibraryCallKit the reexecute bit should not change");
 857 
 858   // If we are guaranteed to throw, we can prune everything but the
 859   // input to the current bytecode.
 860   bool can_prune_locals = false;
 861   uint stack_slots_not_pruned = 0;
 862   int inputs = 0, depth = 0;
 863   if (must_throw) {
 864     assert(method() == youngest_jvms->method(), "sanity");
 865     if (compute_stack_effects(inputs, depth)) {
 866       can_prune_locals = true;
 867       stack_slots_not_pruned = inputs;
 868     }
 869   }
 870 
 871   if (env()->should_retain_local_variables()) {
 872     // At any safepoint, this method can get breakpointed, which would
 873     // then require an immediate deoptimization.
 874     can_prune_locals = false;  // do not prune locals
 875     stack_slots_not_pruned = 0;
 876   }
 877 
 878   // do not scribble on the input jvms
 879   JVMState* out_jvms = youngest_jvms->clone_deep(C);
 880   call->set_jvms(out_jvms); // Start jvms list for call node
 881 
 882   // For a known set of bytecodes, the interpreter should reexecute them if
 883   // deoptimization happens. We set the reexecute state for them here
 884   if (out_jvms->is_reexecute_undefined() && //don't change if already specified
 885       should_reexecute_implied_by_bytecode(out_jvms, call->is_AllocateArray())) {
 886     out_jvms->set_should_reexecute(true); //NOTE: youngest_jvms not changed
 887   }
 888 
 889   // Presize the call:
 890   DEBUG_ONLY(uint non_debug_edges = call->req());
 891   call->add_req_batch(top(), youngest_jvms->debug_depth());
 892   assert(call->req() == non_debug_edges + youngest_jvms->debug_depth(), "");
 893 
 894   // Set up edges so that the call looks like this:
 895   //  Call [state:] ctl io mem fptr retadr
 896   //       [parms:] parm0 ... parmN
 897   //       [root:]  loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN
 898   //    [...mid:]   loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN [...]
 899   //       [young:] loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN
 900   // Note that caller debug info precedes callee debug info.
 901 
 902   // Fill pointer walks backwards from "young:" to "root:" in the diagram above:
 903   uint debug_ptr = call->req();
 904 
 905   // Loop over the map input edges associated with jvms, add them
 906   // to the call node, & reset all offsets to match call node array.
 907   for (JVMState* in_jvms = youngest_jvms; in_jvms != NULL; ) {
 908     uint debug_end   = debug_ptr;
 909     uint debug_start = debug_ptr - in_jvms->debug_size();
 910     debug_ptr = debug_start;  // back up the ptr
 911 
 912     uint p = debug_start;  // walks forward in [debug_start, debug_end)
 913     uint j, k, l;
 914     SafePointNode* in_map = in_jvms->map();
 915     out_jvms->set_map(call);
 916 
 917     if (can_prune_locals) {
 918       assert(in_jvms->method() == out_jvms->method(), "sanity");
 919       // If the current throw can reach an exception handler in this JVMS,
 920       // then we must keep everything live that can reach that handler.
 921       // As a quick and dirty approximation, we look for any handlers at all.
 922       if (in_jvms->method()->has_exception_handlers()) {
 923         can_prune_locals = false;
 924       }
 925     }
 926 
 927     // Add the Locals
 928     k = in_jvms->locoff();
 929     l = in_jvms->loc_size();
 930     out_jvms->set_locoff(p);
 931     if (!can_prune_locals) {
 932       for (j = 0; j < l; j++)
 933         call->set_req(p++, in_map->in(k+j));
 934     } else {
 935       p += l;  // already set to top above by add_req_batch
 936     }
 937 
 938     // Add the Expression Stack
 939     k = in_jvms->stkoff();
 940     l = in_jvms->sp();
 941     out_jvms->set_stkoff(p);
 942     if (!can_prune_locals) {
 943       for (j = 0; j < l; j++)
 944         call->set_req(p++, in_map->in(k+j));
 945     } else if (can_prune_locals && stack_slots_not_pruned != 0) {
 946       // Divide stack into {S0,...,S1}, where S0 is set to top.
 947       uint s1 = stack_slots_not_pruned;
 948       stack_slots_not_pruned = 0;  // for next iteration
 949       if (s1 > l)  s1 = l;
 950       uint s0 = l - s1;
 951       p += s0;  // skip the tops preinstalled by add_req_batch
 952       for (j = s0; j < l; j++)
 953         call->set_req(p++, in_map->in(k+j));
 954     } else {
 955       p += l;  // already set to top above by add_req_batch
 956     }
 957 
 958     // Add the Monitors
 959     k = in_jvms->monoff();
 960     l = in_jvms->mon_size();
 961     out_jvms->set_monoff(p);
 962     for (j = 0; j < l; j++)
 963       call->set_req(p++, in_map->in(k+j));
 964 
 965     // Copy any scalar object fields.
 966     k = in_jvms->scloff();
 967     l = in_jvms->scl_size();
 968     out_jvms->set_scloff(p);
 969     for (j = 0; j < l; j++)
 970       call->set_req(p++, in_map->in(k+j));
 971 
 972     // Finish the new jvms.
 973     out_jvms->set_endoff(p);
 974 
 975     assert(out_jvms->endoff()     == debug_end,             "fill ptr must match");
 976     assert(out_jvms->depth()      == in_jvms->depth(),      "depth must match");
 977     assert(out_jvms->loc_size()   == in_jvms->loc_size(),   "size must match");
 978     assert(out_jvms->mon_size()   == in_jvms->mon_size(),   "size must match");
 979     assert(out_jvms->scl_size()   == in_jvms->scl_size(),   "size must match");
 980     assert(out_jvms->debug_size() == in_jvms->debug_size(), "size must match");
 981 
 982     // Update the two tail pointers in parallel.
 983     out_jvms = out_jvms->caller();
 984     in_jvms  = in_jvms->caller();
 985   }
 986 
 987   assert(debug_ptr == non_debug_edges, "debug info must fit exactly");
 988 
 989   // Test the correctness of JVMState::debug_xxx accessors:
 990   assert(call->jvms()->debug_start() == non_debug_edges, "");
 991   assert(call->jvms()->debug_end()   == call->req(), "");
 992   assert(call->jvms()->debug_depth() == call->req() - non_debug_edges, "");
 993 }
 994 
 995 bool GraphKit::compute_stack_effects(int& inputs, int& depth) {
 996   Bytecodes::Code code = java_bc();
 997   if (code == Bytecodes::_wide) {
 998     code = method()->java_code_at_bci(bci() + 1);
 999   }
1000 
1001   BasicType rtype = T_ILLEGAL;
1002   int       rsize = 0;
1003 
1004   if (code != Bytecodes::_illegal) {
1005     depth = Bytecodes::depth(code); // checkcast=0, athrow=-1
1006     rtype = Bytecodes::result_type(code); // checkcast=P, athrow=V
1007     if (rtype < T_CONFLICT)
1008       rsize = type2size[rtype];
1009   }
1010 
1011   switch (code) {
1012   case Bytecodes::_illegal:
1013     return false;
1014 
1015   case Bytecodes::_ldc:
1016   case Bytecodes::_ldc_w:
1017   case Bytecodes::_ldc2_w:
1018     inputs = 0;
1019     break;
1020 
1021   case Bytecodes::_dup:         inputs = 1;  break;
1022   case Bytecodes::_dup_x1:      inputs = 2;  break;
1023   case Bytecodes::_dup_x2:      inputs = 3;  break;
1024   case Bytecodes::_dup2:        inputs = 2;  break;
1025   case Bytecodes::_dup2_x1:     inputs = 3;  break;
1026   case Bytecodes::_dup2_x2:     inputs = 4;  break;
1027   case Bytecodes::_swap:        inputs = 2;  break;
1028   case Bytecodes::_arraylength: inputs = 1;  break;
1029 
1030   case Bytecodes::_getstatic:
1031   case Bytecodes::_putstatic:
1032   case Bytecodes::_getfield:
1033   case Bytecodes::_putfield:
1034     {
1035       bool ignored_will_link;
1036       ciField* field = method()->get_field_at_bci(bci(), ignored_will_link);
1037       int      size  = field->type()->size();
1038       bool is_get = (depth >= 0), is_static = (depth & 1);
1039       inputs = (is_static ? 0 : 1);
1040       if (is_get) {
1041         depth = size - inputs;
1042       } else {
1043         inputs += size;        // putxxx pops the value from the stack
1044         depth = - inputs;
1045       }
1046     }
1047     break;
1048 
1049   case Bytecodes::_invokevirtual:
1050   case Bytecodes::_invokespecial:
1051   case Bytecodes::_invokestatic:
1052   case Bytecodes::_invokedynamic:
1053   case Bytecodes::_invokeinterface:
1054     {
1055       bool ignored_will_link;
1056       ciSignature* declared_signature = NULL;
1057       ciMethod* ignored_callee = method()->get_method_at_bci(bci(), ignored_will_link, &declared_signature);
1058       assert(declared_signature != NULL, "cannot be null");
1059       inputs   = declared_signature->arg_size_for_bc(code);
1060       int size = declared_signature->return_type()->size();
1061       depth = size - inputs;
1062     }
1063     break;
1064 
1065   case Bytecodes::_multianewarray:
1066     {
1067       ciBytecodeStream iter(method());
1068       iter.reset_to_bci(bci());
1069       iter.next();
1070       inputs = iter.get_dimensions();
1071       assert(rsize == 1, "");
1072       depth = rsize - inputs;
1073     }
1074     break;
1075 
1076   case Bytecodes::_ireturn:
1077   case Bytecodes::_lreturn:
1078   case Bytecodes::_freturn:
1079   case Bytecodes::_dreturn:
1080   case Bytecodes::_areturn:
1081     assert(rsize = -depth, "");
1082     inputs = rsize;
1083     break;
1084 
1085   case Bytecodes::_jsr:
1086   case Bytecodes::_jsr_w:
1087     inputs = 0;
1088     depth  = 1;                  // S.B. depth=1, not zero
1089     break;
1090 
1091   default:
1092     // bytecode produces a typed result
1093     inputs = rsize - depth;
1094     assert(inputs >= 0, "");
1095     break;
1096   }
1097 
1098 #ifdef ASSERT
1099   // spot check
1100   int outputs = depth + inputs;
1101   assert(outputs >= 0, "sanity");
1102   switch (code) {
1103   case Bytecodes::_checkcast: assert(inputs == 1 && outputs == 1, ""); break;
1104   case Bytecodes::_athrow:    assert(inputs == 1 && outputs == 0, ""); break;
1105   case Bytecodes::_aload_0:   assert(inputs == 0 && outputs == 1, ""); break;
1106   case Bytecodes::_return:    assert(inputs == 0 && outputs == 0, ""); break;
1107   case Bytecodes::_drem:      assert(inputs == 4 && outputs == 2, ""); break;
1108   }
1109 #endif //ASSERT
1110 
1111   return true;
1112 }
1113 
1114 
1115 
1116 //------------------------------basic_plus_adr---------------------------------
1117 Node* GraphKit::basic_plus_adr(Node* base, Node* ptr, Node* offset) {
1118   // short-circuit a common case
1119   if (offset == intcon(0))  return ptr;
1120   return _gvn.transform( new AddPNode(base, ptr, offset) );
1121 }
1122 
1123 Node* GraphKit::ConvI2L(Node* offset) {
1124   // short-circuit a common case
1125   jint offset_con = find_int_con(offset, Type::OffsetBot);
1126   if (offset_con != Type::OffsetBot) {
1127     return longcon((jlong) offset_con);
1128   }
1129   return _gvn.transform( new ConvI2LNode(offset));
1130 }
1131 
1132 Node* GraphKit::ConvI2UL(Node* offset) {
1133   juint offset_con = (juint) find_int_con(offset, Type::OffsetBot);
1134   if (offset_con != (juint) Type::OffsetBot) {
1135     return longcon((julong) offset_con);
1136   }
1137   Node* conv = _gvn.transform( new ConvI2LNode(offset));
1138   Node* mask = _gvn.transform(ConLNode::make((julong) max_juint));
1139   return _gvn.transform( new AndLNode(conv, mask) );
1140 }
1141 
1142 Node* GraphKit::ConvL2I(Node* offset) {
1143   // short-circuit a common case
1144   jlong offset_con = find_long_con(offset, (jlong)Type::OffsetBot);
1145   if (offset_con != (jlong)Type::OffsetBot) {
1146     return intcon((int) offset_con);
1147   }
1148   return _gvn.transform( new ConvL2INode(offset));
1149 }
1150 
1151 //-------------------------load_object_klass-----------------------------------
1152 Node* GraphKit::load_object_klass(Node* obj) {
1153   // Special-case a fresh allocation to avoid building nodes:
1154   Node* akls = AllocateNode::Ideal_klass(obj, &_gvn);
1155   if (akls != NULL)  return akls;
1156   Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes());
1157   return _gvn.transform(LoadKlassNode::make(_gvn, NULL, immutable_memory(), k_adr, TypeInstPtr::KLASS));
1158 }
1159 
1160 //-------------------------load_array_length-----------------------------------
1161 Node* GraphKit::load_array_length(Node* array) {
1162   // Special-case a fresh allocation to avoid building nodes:
1163   AllocateArrayNode* alloc = AllocateArrayNode::Ideal_array_allocation(array, &_gvn);
1164   Node *alen;
1165   if (alloc == NULL) {
1166     Node *r_adr = basic_plus_adr(array, arrayOopDesc::length_offset_in_bytes());
1167     alen = _gvn.transform( new LoadRangeNode(0, immutable_memory(), r_adr, TypeInt::POS));
1168   } else {
1169     alen = alloc->Ideal_length();
1170     Node* ccast = alloc->make_ideal_length(_gvn.type(array)->is_oopptr(), &_gvn);
1171     if (ccast != alen) {
1172       alen = _gvn.transform(ccast);
1173     }
1174   }
1175   return alen;
1176 }
1177 
1178 //------------------------------do_null_check----------------------------------
1179 // Helper function to do a NULL pointer check.  Returned value is
1180 // the incoming address with NULL casted away.  You are allowed to use the
1181 // not-null value only if you are control dependent on the test.
1182 extern int explicit_null_checks_inserted,
1183            explicit_null_checks_elided;
1184 Node* GraphKit::null_check_common(Node* value, BasicType type,
1185                                   // optional arguments for variations:
1186                                   bool assert_null,
1187                                   Node* *null_control,
1188                                   bool speculative) {
1189   assert(!assert_null || null_control == NULL, "not both at once");
1190   if (stopped())  return top();
1191   if (!GenerateCompilerNullChecks && !assert_null && null_control == NULL) {
1192     // For some performance testing, we may wish to suppress null checking.
1193     value = cast_not_null(value);   // Make it appear to be non-null (4962416).
1194     return value;
1195   }
1196   explicit_null_checks_inserted++;
1197 
1198   // Construct NULL check
1199   Node *chk = NULL;
1200   switch(type) {
1201     case T_LONG   : chk = new CmpLNode(value, _gvn.zerocon(T_LONG)); break;
1202     case T_INT    : chk = new CmpINode(value, _gvn.intcon(0)); break;
1203     case T_ARRAY  : // fall through
1204       type = T_OBJECT;  // simplify further tests
1205     case T_OBJECT : {
1206       const Type *t = _gvn.type( value );
1207 
1208       const TypeOopPtr* tp = t->isa_oopptr();
1209       if (tp != NULL && tp->klass() != NULL && !tp->klass()->is_loaded()
1210           // Only for do_null_check, not any of its siblings:
1211           && !assert_null && null_control == NULL) {
1212         // Usually, any field access or invocation on an unloaded oop type
1213         // will simply fail to link, since the statically linked class is
1214         // likely also to be unloaded.  However, in -Xcomp mode, sometimes
1215         // the static class is loaded but the sharper oop type is not.
1216         // Rather than checking for this obscure case in lots of places,
1217         // we simply observe that a null check on an unloaded class
1218         // will always be followed by a nonsense operation, so we
1219         // can just issue the uncommon trap here.
1220         // Our access to the unloaded class will only be correct
1221         // after it has been loaded and initialized, which requires
1222         // a trip through the interpreter.
1223 #ifndef PRODUCT
1224         if (WizardMode) { tty->print("Null check of unloaded "); tp->klass()->print(); tty->cr(); }
1225 #endif
1226         uncommon_trap(Deoptimization::Reason_unloaded,
1227                       Deoptimization::Action_reinterpret,
1228                       tp->klass(), "!loaded");
1229         return top();
1230       }
1231 
1232       if (assert_null) {
1233         // See if the type is contained in NULL_PTR.
1234         // If so, then the value is already null.
1235         if (t->higher_equal(TypePtr::NULL_PTR)) {
1236           explicit_null_checks_elided++;
1237           return value;           // Elided null assert quickly!
1238         }
1239       } else {
1240         // See if mixing in the NULL pointer changes type.
1241         // If so, then the NULL pointer was not allowed in the original
1242         // type.  In other words, "value" was not-null.
1243         if (t->meet(TypePtr::NULL_PTR) != t->remove_speculative()) {
1244           // same as: if (!TypePtr::NULL_PTR->higher_equal(t)) ...
1245           explicit_null_checks_elided++;
1246           return value;           // Elided null check quickly!
1247         }
1248       }
1249       chk = new CmpPNode( value, null() );
1250       break;
1251     }
1252 
1253     default:
1254       fatal(err_msg_res("unexpected type: %s", type2name(type)));
1255   }
1256   assert(chk != NULL, "sanity check");
1257   chk = _gvn.transform(chk);
1258 
1259   BoolTest::mask btest = assert_null ? BoolTest::eq : BoolTest::ne;
1260   BoolNode *btst = new BoolNode( chk, btest);
1261   Node   *tst = _gvn.transform( btst );
1262 
1263   //-----------
1264   // if peephole optimizations occurred, a prior test existed.
1265   // If a prior test existed, maybe it dominates as we can avoid this test.
1266   if (tst != btst && type == T_OBJECT) {
1267     // At this point we want to scan up the CFG to see if we can
1268     // find an identical test (and so avoid this test altogether).
1269     Node *cfg = control();
1270     int depth = 0;
1271     while( depth < 16 ) {       // Limit search depth for speed
1272       if( cfg->Opcode() == Op_IfTrue &&
1273           cfg->in(0)->in(1) == tst ) {
1274         // Found prior test.  Use "cast_not_null" to construct an identical
1275         // CastPP (and hence hash to) as already exists for the prior test.
1276         // Return that casted value.
1277         if (assert_null) {
1278           replace_in_map(value, null());
1279           return null();  // do not issue the redundant test
1280         }
1281         Node *oldcontrol = control();
1282         set_control(cfg);
1283         Node *res = cast_not_null(value);
1284         set_control(oldcontrol);
1285         explicit_null_checks_elided++;
1286         return res;
1287       }
1288       cfg = IfNode::up_one_dom(cfg, /*linear_only=*/ true);
1289       if (cfg == NULL)  break;  // Quit at region nodes
1290       depth++;
1291     }
1292   }
1293 
1294   //-----------
1295   // Branch to failure if null
1296   float ok_prob = PROB_MAX;  // a priori estimate:  nulls never happen
1297   Deoptimization::DeoptReason reason;
1298   if (assert_null) {
1299     reason = Deoptimization::Reason_null_assert;
1300   } else if (type == T_OBJECT) {
1301     reason = Deoptimization::reason_null_check(speculative);
1302   } else {
1303     reason = Deoptimization::Reason_div0_check;
1304   }
1305   // %%% Since Reason_unhandled is not recorded on a per-bytecode basis,
1306   // ciMethodData::has_trap_at will return a conservative -1 if any
1307   // must-be-null assertion has failed.  This could cause performance
1308   // problems for a method after its first do_null_assert failure.
1309   // Consider using 'Reason_class_check' instead?
1310 
1311   // To cause an implicit null check, we set the not-null probability
1312   // to the maximum (PROB_MAX).  For an explicit check the probability
1313   // is set to a smaller value.
1314   if (null_control != NULL || too_many_traps(reason)) {
1315     // probability is less likely
1316     ok_prob =  PROB_LIKELY_MAG(3);
1317   } else if (!assert_null &&
1318              (ImplicitNullCheckThreshold > 0) &&
1319              method() != NULL &&
1320              (method()->method_data()->trap_count(reason)
1321               >= (uint)ImplicitNullCheckThreshold)) {
1322     ok_prob =  PROB_LIKELY_MAG(3);
1323   }
1324 
1325   if (null_control != NULL) {
1326     IfNode* iff = create_and_map_if(control(), tst, ok_prob, COUNT_UNKNOWN);
1327     Node* null_true = _gvn.transform( new IfFalseNode(iff));
1328     set_control(      _gvn.transform( new IfTrueNode(iff)));
1329     if (null_true == top())
1330       explicit_null_checks_elided++;
1331     (*null_control) = null_true;
1332   } else {
1333     BuildCutout unless(this, tst, ok_prob);
1334     // Check for optimizer eliding test at parse time
1335     if (stopped()) {
1336       // Failure not possible; do not bother making uncommon trap.
1337       explicit_null_checks_elided++;
1338     } else if (assert_null) {
1339       uncommon_trap(reason,
1340                     Deoptimization::Action_make_not_entrant,
1341                     NULL, "assert_null");
1342     } else {
1343       replace_in_map(value, zerocon(type));
1344       builtin_throw(reason);
1345     }
1346   }
1347 
1348   // Must throw exception, fall-thru not possible?
1349   if (stopped()) {
1350     return top();               // No result
1351   }
1352 
1353   if (assert_null) {
1354     // Cast obj to null on this path.
1355     replace_in_map(value, zerocon(type));
1356     return zerocon(type);
1357   }
1358 
1359   // Cast obj to not-null on this path, if there is no null_control.
1360   // (If there is a null_control, a non-null value may come back to haunt us.)
1361   if (type == T_OBJECT) {
1362     Node* cast = cast_not_null(value, false);
1363     if (null_control == NULL || (*null_control) == top())
1364       replace_in_map(value, cast);
1365     value = cast;
1366   }
1367 
1368   return value;
1369 }
1370 
1371 
1372 //------------------------------cast_not_null----------------------------------
1373 // Cast obj to not-null on this path
1374 Node* GraphKit::cast_not_null(Node* obj, bool do_replace_in_map) {
1375   const Type *t = _gvn.type(obj);
1376   const Type *t_not_null = t->join_speculative(TypePtr::NOTNULL);
1377   // Object is already not-null?
1378   if( t == t_not_null ) return obj;
1379 
1380   Node *cast = new CastPPNode(obj,t_not_null);
1381   cast->init_req(0, control());
1382   cast = _gvn.transform( cast );
1383 
1384   // Scan for instances of 'obj' in the current JVM mapping.
1385   // These instances are known to be not-null after the test.
1386   if (do_replace_in_map)
1387     replace_in_map(obj, cast);
1388 
1389   return cast;                  // Return casted value
1390 }
1391 
1392 
1393 //--------------------------replace_in_map-------------------------------------
1394 void GraphKit::replace_in_map(Node* old, Node* neww) {
1395   if (old == neww) {
1396     return;
1397   }
1398 
1399   map()->replace_edge(old, neww);
1400 
1401   // Note: This operation potentially replaces any edge
1402   // on the map.  This includes locals, stack, and monitors
1403   // of the current (innermost) JVM state.
1404 
1405   // don't let inconsistent types from profiling escape this
1406   // method
1407 
1408   const Type* told = _gvn.type(old);
1409   const Type* tnew = _gvn.type(neww);
1410 
1411   if (!tnew->higher_equal(told)) {
1412     return;
1413   }
1414 
1415   map()->record_replaced_node(old, neww);
1416 }
1417 
1418 
1419 //=============================================================================
1420 //--------------------------------memory---------------------------------------
1421 Node* GraphKit::memory(uint alias_idx) {
1422   MergeMemNode* mem = merged_memory();
1423   Node* p = mem->memory_at(alias_idx);
1424   _gvn.set_type(p, Type::MEMORY);  // must be mapped
1425   return p;
1426 }
1427 
1428 //-----------------------------reset_memory------------------------------------
1429 Node* GraphKit::reset_memory() {
1430   Node* mem = map()->memory();
1431   // do not use this node for any more parsing!
1432   debug_only( map()->set_memory((Node*)NULL) );
1433   return _gvn.transform( mem );
1434 }
1435 
1436 //------------------------------set_all_memory---------------------------------
1437 void GraphKit::set_all_memory(Node* newmem) {
1438   Node* mergemem = MergeMemNode::make(newmem);
1439   gvn().set_type_bottom(mergemem);
1440   map()->set_memory(mergemem);
1441 }
1442 
1443 //------------------------------set_all_memory_call----------------------------
1444 void GraphKit::set_all_memory_call(Node* call, bool separate_io_proj) {
1445   Node* newmem = _gvn.transform( new ProjNode(call, TypeFunc::Memory, separate_io_proj) );
1446   set_all_memory(newmem);
1447 }
1448 
1449 //=============================================================================
1450 //
1451 // parser factory methods for MemNodes
1452 //
1453 // These are layered on top of the factory methods in LoadNode and StoreNode,
1454 // and integrate with the parser's memory state and _gvn engine.
1455 //
1456 
1457 // factory methods in "int adr_idx"
1458 Node* GraphKit::make_load(Node* ctl, Node* adr, const Type* t, BasicType bt,
1459                           int adr_idx,
1460                           MemNode::MemOrd mo, bool require_atomic_access) {
1461   assert(adr_idx != Compile::AliasIdxTop, "use other make_load factory" );
1462   const TypePtr* adr_type = NULL; // debug-mode-only argument
1463   debug_only(adr_type = C->get_adr_type(adr_idx));
1464   Node* mem = memory(adr_idx);
1465   Node* ld;
1466   if (require_atomic_access && bt == T_LONG) {
1467     ld = LoadLNode::make_atomic(ctl, mem, adr, adr_type, t, mo);
1468   } else if (require_atomic_access && bt == T_DOUBLE) {
1469     ld = LoadDNode::make_atomic(ctl, mem, adr, adr_type, t, mo);
1470   } else {
1471     ld = LoadNode::make(_gvn, ctl, mem, adr, adr_type, t, bt, mo);
1472   }
1473   ld = _gvn.transform(ld);
1474   if ((bt == T_OBJECT) && C->do_escape_analysis() || C->eliminate_boxing()) {
1475     // Improve graph before escape analysis and boxing elimination.
1476     record_for_igvn(ld);
1477   }
1478   return ld;
1479 }
1480 
1481 Node* GraphKit::store_to_memory(Node* ctl, Node* adr, Node *val, BasicType bt,
1482                                 int adr_idx,
1483                                 MemNode::MemOrd mo,
1484                                 bool require_atomic_access) {
1485   assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
1486   const TypePtr* adr_type = NULL;
1487   debug_only(adr_type = C->get_adr_type(adr_idx));
1488   Node *mem = memory(adr_idx);
1489   Node* st;
1490   if (require_atomic_access && bt == T_LONG) {
1491     st = StoreLNode::make_atomic(ctl, mem, adr, adr_type, val, mo);
1492   } else if (require_atomic_access && bt == T_DOUBLE) {
1493     st = StoreDNode::make_atomic(ctl, mem, adr, adr_type, val, mo);
1494   } else {
1495     st = StoreNode::make(_gvn, ctl, mem, adr, adr_type, val, bt, mo);
1496   }
1497   st = _gvn.transform(st);
1498   set_memory(st, adr_idx);
1499   // Back-to-back stores can only remove intermediate store with DU info
1500   // so push on worklist for optimizer.
1501   if (mem->req() > MemNode::Address && adr == mem->in(MemNode::Address))
1502     record_for_igvn(st);
1503 
1504   return st;
1505 }
1506 
1507 
1508 void GraphKit::pre_barrier(bool do_load,
1509                            Node* ctl,
1510                            Node* obj,
1511                            Node* adr,
1512                            uint  adr_idx,
1513                            Node* val,
1514                            const TypeOopPtr* val_type,
1515                            Node* pre_val,
1516                            BasicType bt) {
1517 
1518   BarrierSet* bs = Universe::heap()->barrier_set();
1519   set_control(ctl);
1520   switch (bs->kind()) {
1521     case BarrierSet::G1SATBCT:
1522     case BarrierSet::G1SATBCTLogging:
1523       g1_write_barrier_pre(do_load, obj, adr, adr_idx, val, val_type, pre_val, bt);
1524       break;
1525 
1526     case BarrierSet::CardTableModRef:
1527     case BarrierSet::CardTableExtension:
1528     case BarrierSet::ModRef:
1529       break;
1530 
1531     case BarrierSet::Other:
1532     default      :
1533       ShouldNotReachHere();
1534 
1535   }
1536 }
1537 
1538 bool GraphKit::can_move_pre_barrier() const {
1539   BarrierSet* bs = Universe::heap()->barrier_set();
1540   switch (bs->kind()) {
1541     case BarrierSet::G1SATBCT:
1542     case BarrierSet::G1SATBCTLogging:
1543       return true; // Can move it if no safepoint
1544 
1545     case BarrierSet::CardTableModRef:
1546     case BarrierSet::CardTableExtension:
1547     case BarrierSet::ModRef:
1548       return true; // There is no pre-barrier
1549 
1550     case BarrierSet::Other:
1551     default      :
1552       ShouldNotReachHere();
1553   }
1554   return false;
1555 }
1556 
1557 void GraphKit::post_barrier(Node* ctl,
1558                             Node* store,
1559                             Node* obj,
1560                             Node* adr,
1561                             uint  adr_idx,
1562                             Node* val,
1563                             BasicType bt,
1564                             bool use_precise) {
1565   BarrierSet* bs = Universe::heap()->barrier_set();
1566   set_control(ctl);
1567   switch (bs->kind()) {
1568     case BarrierSet::G1SATBCT:
1569     case BarrierSet::G1SATBCTLogging:
1570       g1_write_barrier_post(store, obj, adr, adr_idx, val, bt, use_precise);
1571       break;
1572 
1573     case BarrierSet::CardTableModRef:
1574     case BarrierSet::CardTableExtension:
1575       write_barrier_post(store, obj, adr, adr_idx, val, use_precise);
1576       break;
1577 
1578     case BarrierSet::ModRef:
1579       break;
1580 
1581     case BarrierSet::Other:
1582     default      :
1583       ShouldNotReachHere();
1584 
1585   }
1586 }
1587 
1588 Node* GraphKit::store_oop(Node* ctl,
1589                           Node* obj,
1590                           Node* adr,
1591                           const TypePtr* adr_type,
1592                           Node* val,
1593                           const TypeOopPtr* val_type,
1594                           BasicType bt,
1595                           bool use_precise,
1596                           MemNode::MemOrd mo) {
1597   // Transformation of a value which could be NULL pointer (CastPP #NULL)
1598   // could be delayed during Parse (for example, in adjust_map_after_if()).
1599   // Execute transformation here to avoid barrier generation in such case.
1600   if (_gvn.type(val) == TypePtr::NULL_PTR)
1601     val = _gvn.makecon(TypePtr::NULL_PTR);
1602 
1603   set_control(ctl);
1604   if (stopped()) return top(); // Dead path ?
1605 
1606   assert(bt == T_OBJECT, "sanity");
1607   assert(val != NULL, "not dead path");
1608   uint adr_idx = C->get_alias_index(adr_type);
1609   assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
1610 
1611   pre_barrier(true /* do_load */,
1612               control(), obj, adr, adr_idx, val, val_type,
1613               NULL /* pre_val */,
1614               bt);
1615 
1616   Node* store = store_to_memory(control(), adr, val, bt, adr_idx, mo);
1617   post_barrier(control(), store, obj, adr, adr_idx, val, bt, use_precise);
1618   return store;
1619 }
1620 
1621 // Could be an array or object we don't know at compile time (unsafe ref.)
1622 Node* GraphKit::store_oop_to_unknown(Node* ctl,
1623                              Node* obj,   // containing obj
1624                              Node* adr,  // actual adress to store val at
1625                              const TypePtr* adr_type,
1626                              Node* val,
1627                              BasicType bt,
1628                              MemNode::MemOrd mo) {
1629   Compile::AliasType* at = C->alias_type(adr_type);
1630   const TypeOopPtr* val_type = NULL;
1631   if (adr_type->isa_instptr()) {
1632     if (at->field() != NULL) {
1633       // known field.  This code is a copy of the do_put_xxx logic.
1634       ciField* field = at->field();
1635       if (!field->type()->is_loaded()) {
1636         val_type = TypeInstPtr::BOTTOM;
1637       } else {
1638         val_type = TypeOopPtr::make_from_klass(field->type()->as_klass());
1639       }
1640     }
1641   } else if (adr_type->isa_aryptr()) {
1642     val_type = adr_type->is_aryptr()->elem()->make_oopptr();
1643   }
1644   if (val_type == NULL) {
1645     val_type = TypeInstPtr::BOTTOM;
1646   }
1647   return store_oop(ctl, obj, adr, adr_type, val, val_type, bt, true, mo);
1648 }
1649 
1650 
1651 //-------------------------array_element_address-------------------------
1652 Node* GraphKit::array_element_address(Node* ary, Node* idx, BasicType elembt,
1653                                       const TypeInt* sizetype) {
1654   uint shift  = exact_log2(type2aelembytes(elembt));
1655   uint header = arrayOopDesc::base_offset_in_bytes(elembt);
1656 
1657   // short-circuit a common case (saves lots of confusing waste motion)
1658   jint idx_con = find_int_con(idx, -1);
1659   if (idx_con >= 0) {
1660     intptr_t offset = header + ((intptr_t)idx_con << shift);
1661     return basic_plus_adr(ary, offset);
1662   }
1663 
1664   // must be correct type for alignment purposes
1665   Node* base  = basic_plus_adr(ary, header);
1666 #ifdef _LP64
1667   // The scaled index operand to AddP must be a clean 64-bit value.
1668   // Java allows a 32-bit int to be incremented to a negative
1669   // value, which appears in a 64-bit register as a large
1670   // positive number.  Using that large positive number as an
1671   // operand in pointer arithmetic has bad consequences.
1672   // On the other hand, 32-bit overflow is rare, and the possibility
1673   // can often be excluded, if we annotate the ConvI2L node with
1674   // a type assertion that its value is known to be a small positive
1675   // number.  (The prior range check has ensured this.)
1676   // This assertion is used by ConvI2LNode::Ideal.
1677   int index_max = max_jint - 1;  // array size is max_jint, index is one less
1678   if (sizetype != NULL)  index_max = sizetype->_hi - 1;
1679   const TypeLong* lidxtype = TypeLong::make(CONST64(0), index_max, Type::WidenMax);
1680   idx = _gvn.transform( new ConvI2LNode(idx, lidxtype) );
1681 #endif
1682   Node* scale = _gvn.transform( new LShiftXNode(idx, intcon(shift)) );
1683   return basic_plus_adr(ary, base, scale);
1684 }
1685 
1686 //-------------------------load_array_element-------------------------
1687 Node* GraphKit::load_array_element(Node* ctl, Node* ary, Node* idx, const TypeAryPtr* arytype) {
1688   const Type* elemtype = arytype->elem();
1689   BasicType elembt = elemtype->array_element_basic_type();
1690   Node* adr = array_element_address(ary, idx, elembt, arytype->size());
1691   Node* ld = make_load(ctl, adr, elemtype, elembt, arytype, MemNode::unordered);
1692   return ld;
1693 }
1694 
1695 //-------------------------set_arguments_for_java_call-------------------------
1696 // Arguments (pre-popped from the stack) are taken from the JVMS.
1697 void GraphKit::set_arguments_for_java_call(CallJavaNode* call) {
1698   // Add the call arguments:
1699   uint nargs = call->method()->arg_size();
1700   for (uint i = 0; i < nargs; i++) {
1701     Node* arg = argument(i);
1702     call->init_req(i + TypeFunc::Parms, arg);
1703   }
1704 }
1705 
1706 //---------------------------set_edges_for_java_call---------------------------
1707 // Connect a newly created call into the current JVMS.
1708 // A return value node (if any) is returned from set_edges_for_java_call.
1709 void GraphKit::set_edges_for_java_call(CallJavaNode* call, bool must_throw, bool separate_io_proj) {
1710 
1711   // Add the predefined inputs:
1712   call->init_req( TypeFunc::Control, control() );
1713   call->init_req( TypeFunc::I_O    , i_o() );
1714   call->init_req( TypeFunc::Memory , reset_memory() );
1715   call->init_req( TypeFunc::FramePtr, frameptr() );
1716   call->init_req( TypeFunc::ReturnAdr, top() );
1717 
1718   add_safepoint_edges(call, must_throw);
1719 
1720   Node* xcall = _gvn.transform(call);
1721 
1722   if (xcall == top()) {
1723     set_control(top());
1724     return;
1725   }
1726   assert(xcall == call, "call identity is stable");
1727 
1728   // Re-use the current map to produce the result.
1729 
1730   set_control(_gvn.transform(new ProjNode(call, TypeFunc::Control)));
1731   set_i_o(    _gvn.transform(new ProjNode(call, TypeFunc::I_O    , separate_io_proj)));
1732   set_all_memory_call(xcall, separate_io_proj);
1733 
1734   //return xcall;   // no need, caller already has it
1735 }
1736 
1737 Node* GraphKit::set_results_for_java_call(CallJavaNode* call, bool separate_io_proj) {
1738   if (stopped())  return top();  // maybe the call folded up?
1739 
1740   // Capture the return value, if any.
1741   Node* ret;
1742   if (call->method() == NULL ||
1743       call->method()->return_type()->basic_type() == T_VOID)
1744         ret = top();
1745   else  ret = _gvn.transform(new ProjNode(call, TypeFunc::Parms));
1746 
1747   // Note:  Since any out-of-line call can produce an exception,
1748   // we always insert an I_O projection from the call into the result.
1749 
1750   make_slow_call_ex(call, env()->Throwable_klass(), separate_io_proj);
1751 
1752   if (separate_io_proj) {
1753     // The caller requested separate projections be used by the fall
1754     // through and exceptional paths, so replace the projections for
1755     // the fall through path.
1756     set_i_o(_gvn.transform( new ProjNode(call, TypeFunc::I_O) ));
1757     set_all_memory(_gvn.transform( new ProjNode(call, TypeFunc::Memory) ));
1758   }
1759   return ret;
1760 }
1761 
1762 //--------------------set_predefined_input_for_runtime_call--------------------
1763 // Reading and setting the memory state is way conservative here.
1764 // The real problem is that I am not doing real Type analysis on memory,
1765 // so I cannot distinguish card mark stores from other stores.  Across a GC
1766 // point the Store Barrier and the card mark memory has to agree.  I cannot
1767 // have a card mark store and its barrier split across the GC point from
1768 // either above or below.  Here I get that to happen by reading ALL of memory.
1769 // A better answer would be to separate out card marks from other memory.
1770 // For now, return the input memory state, so that it can be reused
1771 // after the call, if this call has restricted memory effects.
1772 Node* GraphKit::set_predefined_input_for_runtime_call(SafePointNode* call) {
1773   // Set fixed predefined input arguments
1774   Node* memory = reset_memory();
1775   call->init_req( TypeFunc::Control,   control()  );
1776   call->init_req( TypeFunc::I_O,       top()      ); // does no i/o
1777   call->init_req( TypeFunc::Memory,    memory     ); // may gc ptrs
1778   call->init_req( TypeFunc::FramePtr,  frameptr() );
1779   call->init_req( TypeFunc::ReturnAdr, top()      );
1780   return memory;
1781 }
1782 
1783 //-------------------set_predefined_output_for_runtime_call--------------------
1784 // Set control and memory (not i_o) from the call.
1785 // If keep_mem is not NULL, use it for the output state,
1786 // except for the RawPtr output of the call, if hook_mem is TypeRawPtr::BOTTOM.
1787 // If hook_mem is NULL, this call produces no memory effects at all.
1788 // If hook_mem is a Java-visible memory slice (such as arraycopy operands),
1789 // then only that memory slice is taken from the call.
1790 // In the last case, we must put an appropriate memory barrier before
1791 // the call, so as to create the correct anti-dependencies on loads
1792 // preceding the call.
1793 void GraphKit::set_predefined_output_for_runtime_call(Node* call,
1794                                                       Node* keep_mem,
1795                                                       const TypePtr* hook_mem) {
1796   // no i/o
1797   set_control(_gvn.transform( new ProjNode(call,TypeFunc::Control) ));
1798   if (keep_mem) {
1799     // First clone the existing memory state
1800     set_all_memory(keep_mem);
1801     if (hook_mem != NULL) {
1802       // Make memory for the call
1803       Node* mem = _gvn.transform( new ProjNode(call, TypeFunc::Memory) );
1804       // Set the RawPtr memory state only.  This covers all the heap top/GC stuff
1805       // We also use hook_mem to extract specific effects from arraycopy stubs.
1806       set_memory(mem, hook_mem);
1807     }
1808     // ...else the call has NO memory effects.
1809 
1810     // Make sure the call advertises its memory effects precisely.
1811     // This lets us build accurate anti-dependences in gcm.cpp.
1812     assert(C->alias_type(call->adr_type()) == C->alias_type(hook_mem),
1813            "call node must be constructed correctly");
1814   } else {
1815     assert(hook_mem == NULL, "");
1816     // This is not a "slow path" call; all memory comes from the call.
1817     set_all_memory_call(call);
1818   }
1819 }
1820 
1821 
1822 // Replace the call with the current state of the kit.
1823 void GraphKit::replace_call(CallNode* call, Node* result, bool do_replaced_nodes) {
1824   JVMState* ejvms = NULL;
1825   if (has_exceptions()) {
1826     ejvms = transfer_exceptions_into_jvms();
1827   }
1828 
1829   ReplacedNodes replaced_nodes = map()->replaced_nodes();
1830   ReplacedNodes replaced_nodes_exception;
1831   Node* ex_ctl = top();
1832 
1833   SafePointNode* final_state = stop();
1834 
1835   // Find all the needed outputs of this call
1836   CallProjections callprojs;
1837   call->extract_projections(&callprojs, true);
1838 
1839   Node* init_mem = call->in(TypeFunc::Memory);
1840   Node* final_mem = final_state->in(TypeFunc::Memory);
1841   Node* final_ctl = final_state->in(TypeFunc::Control);
1842   Node* final_io = final_state->in(TypeFunc::I_O);
1843 
1844   // Replace all the old call edges with the edges from the inlining result
1845   if (callprojs.fallthrough_catchproj != NULL) {
1846     C->gvn_replace_by(callprojs.fallthrough_catchproj, final_ctl);
1847   }
1848   if (callprojs.fallthrough_memproj != NULL) {
1849     if (final_mem->is_MergeMem()) {
1850       // Parser's exits MergeMem was not transformed but may be optimized
1851       final_mem = _gvn.transform(final_mem);
1852     }
1853     C->gvn_replace_by(callprojs.fallthrough_memproj,   final_mem);
1854   }
1855   if (callprojs.fallthrough_ioproj != NULL) {
1856     C->gvn_replace_by(callprojs.fallthrough_ioproj,    final_io);
1857   }
1858 
1859   // Replace the result with the new result if it exists and is used
1860   if (callprojs.resproj != NULL && result != NULL) {
1861     C->gvn_replace_by(callprojs.resproj, result);
1862   }
1863 
1864   if (ejvms == NULL) {
1865     // No exception edges to simply kill off those paths
1866     if (callprojs.catchall_catchproj != NULL) {
1867       C->gvn_replace_by(callprojs.catchall_catchproj, C->top());
1868     }
1869     if (callprojs.catchall_memproj != NULL) {
1870       C->gvn_replace_by(callprojs.catchall_memproj,   C->top());
1871     }
1872     if (callprojs.catchall_ioproj != NULL) {
1873       C->gvn_replace_by(callprojs.catchall_ioproj,    C->top());
1874     }
1875     // Replace the old exception object with top
1876     if (callprojs.exobj != NULL) {
1877       C->gvn_replace_by(callprojs.exobj, C->top());
1878     }
1879   } else {
1880     GraphKit ekit(ejvms);
1881 
1882     // Load my combined exception state into the kit, with all phis transformed:
1883     SafePointNode* ex_map = ekit.combine_and_pop_all_exception_states();
1884     replaced_nodes_exception = ex_map->replaced_nodes();
1885 
1886     Node* ex_oop = ekit.use_exception_state(ex_map);
1887 
1888     if (callprojs.catchall_catchproj != NULL) {
1889       C->gvn_replace_by(callprojs.catchall_catchproj, ekit.control());
1890       ex_ctl = ekit.control();
1891     }
1892     if (callprojs.catchall_memproj != NULL) {
1893       C->gvn_replace_by(callprojs.catchall_memproj,   ekit.reset_memory());
1894     }
1895     if (callprojs.catchall_ioproj != NULL) {
1896       C->gvn_replace_by(callprojs.catchall_ioproj,    ekit.i_o());
1897     }
1898 
1899     // Replace the old exception object with the newly created one
1900     if (callprojs.exobj != NULL) {
1901       C->gvn_replace_by(callprojs.exobj, ex_oop);
1902     }
1903   }
1904 
1905   // Disconnect the call from the graph
1906   call->disconnect_inputs(NULL, C);
1907   C->gvn_replace_by(call, C->top());
1908 
1909   // Clean up any MergeMems that feed other MergeMems since the
1910   // optimizer doesn't like that.
1911   if (final_mem->is_MergeMem()) {
1912     Node_List wl;
1913     for (SimpleDUIterator i(final_mem); i.has_next(); i.next()) {
1914       Node* m = i.get();
1915       if (m->is_MergeMem() && !wl.contains(m)) {
1916         wl.push(m);
1917       }
1918     }
1919     while (wl.size()  > 0) {
1920       _gvn.transform(wl.pop());
1921     }
1922   }
1923 
1924   if (callprojs.fallthrough_catchproj != NULL && !final_ctl->is_top() && do_replaced_nodes) {
1925     replaced_nodes.apply(C, final_ctl);
1926   }
1927   if (!ex_ctl->is_top() && do_replaced_nodes) {
1928     replaced_nodes_exception.apply(C, ex_ctl);
1929   }
1930 }
1931 
1932 
1933 //------------------------------increment_counter------------------------------
1934 // for statistics: increment a VM counter by 1
1935 
1936 void GraphKit::increment_counter(address counter_addr) {
1937   Node* adr1 = makecon(TypeRawPtr::make(counter_addr));
1938   increment_counter(adr1);
1939 }
1940 
1941 void GraphKit::increment_counter(Node* counter_addr) {
1942   int adr_type = Compile::AliasIdxRaw;
1943   Node* ctrl = control();
1944   Node* cnt  = make_load(ctrl, counter_addr, TypeInt::INT, T_INT, adr_type, MemNode::unordered);
1945   Node* incr = _gvn.transform(new AddINode(cnt, _gvn.intcon(1)));
1946   store_to_memory(ctrl, counter_addr, incr, T_INT, adr_type, MemNode::unordered);
1947 }
1948 
1949 
1950 //------------------------------uncommon_trap----------------------------------
1951 // Bail out to the interpreter in mid-method.  Implemented by calling the
1952 // uncommon_trap blob.  This helper function inserts a runtime call with the
1953 // right debug info.
1954 void GraphKit::uncommon_trap(int trap_request,
1955                              ciKlass* klass, const char* comment,
1956                              bool must_throw,
1957                              bool keep_exact_action) {
1958   if (failing())  stop();
1959   if (stopped())  return; // trap reachable?
1960 
1961   // Note:  If ProfileTraps is true, and if a deopt. actually
1962   // occurs here, the runtime will make sure an MDO exists.  There is
1963   // no need to call method()->ensure_method_data() at this point.
1964 
1965   // Set the stack pointer to the right value for reexecution:
1966   set_sp(reexecute_sp());
1967 
1968 #ifdef ASSERT
1969   if (!must_throw) {
1970     // Make sure the stack has at least enough depth to execute
1971     // the current bytecode.
1972     int inputs, ignored_depth;
1973     if (compute_stack_effects(inputs, ignored_depth)) {
1974       assert(sp() >= inputs, err_msg_res("must have enough JVMS stack to execute %s: sp=%d, inputs=%d",
1975              Bytecodes::name(java_bc()), sp(), inputs));
1976     }
1977   }
1978 #endif
1979 
1980   Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(trap_request);
1981   Deoptimization::DeoptAction action = Deoptimization::trap_request_action(trap_request);
1982 
1983   switch (action) {
1984   case Deoptimization::Action_maybe_recompile:
1985   case Deoptimization::Action_reinterpret:
1986     // Temporary fix for 6529811 to allow virtual calls to be sure they
1987     // get the chance to go from mono->bi->mega
1988     if (!keep_exact_action &&
1989         Deoptimization::trap_request_index(trap_request) < 0 &&
1990         too_many_recompiles(reason)) {
1991       // This BCI is causing too many recompilations.
1992       if (C->log() != NULL) {
1993         C->log()->elem("observe that='trap_action_change' reason='%s' from='%s' to='none'",
1994                 Deoptimization::trap_reason_name(reason),
1995                 Deoptimization::trap_action_name(action));
1996       }
1997       action = Deoptimization::Action_none;
1998       trap_request = Deoptimization::make_trap_request(reason, action);
1999     } else {
2000       C->set_trap_can_recompile(true);
2001     }
2002     break;
2003   case Deoptimization::Action_make_not_entrant:
2004     C->set_trap_can_recompile(true);
2005     break;
2006 #ifdef ASSERT
2007   case Deoptimization::Action_none:
2008   case Deoptimization::Action_make_not_compilable:
2009     break;
2010   default:
2011     fatal(err_msg_res("unknown action %d: %s", action, Deoptimization::trap_action_name(action)));
2012     break;
2013 #endif
2014   }
2015 
2016   if (TraceOptoParse) {
2017     char buf[100];
2018     tty->print_cr("Uncommon trap %s at bci:%d",
2019                   Deoptimization::format_trap_request(buf, sizeof(buf),
2020                                                       trap_request), bci());
2021   }
2022 
2023   CompileLog* log = C->log();
2024   if (log != NULL) {
2025     int kid = (klass == NULL)? -1: log->identify(klass);
2026     log->begin_elem("uncommon_trap bci='%d'", bci());
2027     char buf[100];
2028     log->print(" %s", Deoptimization::format_trap_request(buf, sizeof(buf),
2029                                                           trap_request));
2030     if (kid >= 0)         log->print(" klass='%d'", kid);
2031     if (comment != NULL)  log->print(" comment='%s'", comment);
2032     log->end_elem();
2033   }
2034 
2035   // Make sure any guarding test views this path as very unlikely
2036   Node *i0 = control()->in(0);
2037   if (i0 != NULL && i0->is_If()) {        // Found a guarding if test?
2038     IfNode *iff = i0->as_If();
2039     float f = iff->_prob;   // Get prob
2040     if (control()->Opcode() == Op_IfTrue) {
2041       if (f > PROB_UNLIKELY_MAG(4))
2042         iff->_prob = PROB_MIN;
2043     } else {
2044       if (f < PROB_LIKELY_MAG(4))
2045         iff->_prob = PROB_MAX;
2046     }
2047   }
2048 
2049   // Clear out dead values from the debug info.
2050   kill_dead_locals();
2051 
2052   // Now insert the uncommon trap subroutine call
2053   address call_addr = SharedRuntime::uncommon_trap_blob()->entry_point();
2054   const TypePtr* no_memory_effects = NULL;
2055   // Pass the index of the class to be loaded
2056   Node* call = make_runtime_call(RC_NO_LEAF | RC_UNCOMMON |
2057                                  (must_throw ? RC_MUST_THROW : 0),
2058                                  OptoRuntime::uncommon_trap_Type(),
2059                                  call_addr, "uncommon_trap", no_memory_effects,
2060                                  intcon(trap_request));
2061   assert(call->as_CallStaticJava()->uncommon_trap_request() == trap_request,
2062          "must extract request correctly from the graph");
2063   assert(trap_request != 0, "zero value reserved by uncommon_trap_request");
2064 
2065   call->set_req(TypeFunc::ReturnAdr, returnadr());
2066   // The debug info is the only real input to this call.
2067 
2068   // Halt-and-catch fire here.  The above call should never return!
2069   HaltNode* halt = new HaltNode(control(), frameptr());
2070   _gvn.set_type_bottom(halt);
2071   root()->add_req(halt);
2072 
2073   stop_and_kill_map();
2074 }
2075 
2076 
2077 //--------------------------just_allocated_object------------------------------
2078 // Report the object that was just allocated.
2079 // It must be the case that there are no intervening safepoints.
2080 // We use this to determine if an object is so "fresh" that
2081 // it does not require card marks.
2082 Node* GraphKit::just_allocated_object(Node* current_control) {
2083   if (C->recent_alloc_ctl() == current_control)
2084     return C->recent_alloc_obj();
2085   return NULL;
2086 }
2087 
2088 
2089 void GraphKit::round_double_arguments(ciMethod* dest_method) {
2090   // (Note:  TypeFunc::make has a cache that makes this fast.)
2091   const TypeFunc* tf    = TypeFunc::make(dest_method);
2092   int             nargs = tf->domain()->cnt() - TypeFunc::Parms;
2093   for (int j = 0; j < nargs; j++) {
2094     const Type *targ = tf->domain()->field_at(j + TypeFunc::Parms);
2095     if( targ->basic_type() == T_DOUBLE ) {
2096       // If any parameters are doubles, they must be rounded before
2097       // the call, dstore_rounding does gvn.transform
2098       Node *arg = argument(j);
2099       arg = dstore_rounding(arg);
2100       set_argument(j, arg);
2101     }
2102   }
2103 }
2104 
2105 /**
2106  * Record profiling data exact_kls for Node n with the type system so
2107  * that it can propagate it (speculation)
2108  *
2109  * @param n          node that the type applies to
2110  * @param exact_kls  type from profiling
2111  * @param maybe_null did profiling see null?
2112  *
2113  * @return           node with improved type
2114  */
2115 Node* GraphKit::record_profile_for_speculation(Node* n, ciKlass* exact_kls, bool maybe_null) {
2116   const Type* current_type = _gvn.type(n);
2117   assert(UseTypeSpeculation, "type speculation must be on");
2118 
2119   const TypePtr* speculative = current_type->speculative();
2120 
2121   // Should the klass from the profile be recorded in the speculative type?
2122   if (current_type->would_improve_type(exact_kls, jvms()->depth())) {
2123     const TypeKlassPtr* tklass = TypeKlassPtr::make(exact_kls);
2124     const TypeOopPtr* xtype = tklass->as_instance_type();
2125     assert(xtype->klass_is_exact(), "Should be exact");
2126     // Any reason to believe n is not null (from this profiling or a previous one)?
2127     const TypePtr* ptr = (maybe_null && current_type->speculative_maybe_null()) ? TypePtr::BOTTOM : TypePtr::NOTNULL;
2128     // record the new speculative type's depth
2129     speculative = xtype->cast_to_ptr_type(ptr->ptr())->is_ptr();
2130     speculative = speculative->with_inline_depth(jvms()->depth());
2131   } else if (current_type->would_improve_ptr(maybe_null)) {
2132     // Profiling report that null was never seen so we can change the
2133     // speculative type to non null ptr.
2134     assert(!maybe_null, "nothing to improve");
2135     if (speculative == NULL) {
2136       speculative = TypePtr::NOTNULL;
2137     } else {
2138       const TypePtr* ptr = TypePtr::NOTNULL;
2139       speculative = speculative->cast_to_ptr_type(ptr->ptr())->is_ptr();
2140     }
2141   }
2142 
2143   if (speculative != current_type->speculative()) {
2144     // Build a type with a speculative type (what we think we know
2145     // about the type but will need a guard when we use it)
2146     const TypeOopPtr* spec_type = TypeOopPtr::make(TypePtr::BotPTR, Type::OffsetBot, TypeOopPtr::InstanceBot, speculative);
2147     // We're changing the type, we need a new CheckCast node to carry
2148     // the new type. The new type depends on the control: what
2149     // profiling tells us is only valid from here as far as we can
2150     // tell.
2151     Node* cast = new CheckCastPPNode(control(), n, current_type->remove_speculative()->join_speculative(spec_type));
2152     cast = _gvn.transform(cast);
2153     replace_in_map(n, cast);
2154     n = cast;
2155   }
2156 
2157   return n;
2158 }
2159 
2160 /**
2161  * Record profiling data from receiver profiling at an invoke with the
2162  * type system so that it can propagate it (speculation)
2163  *
2164  * @param n  receiver node
2165  *
2166  * @return   node with improved type
2167  */
2168 Node* GraphKit::record_profiled_receiver_for_speculation(Node* n) {
2169   if (!UseTypeSpeculation) {
2170     return n;
2171   }
2172   ciKlass* exact_kls = profile_has_unique_klass();
2173   bool maybe_null = true;
2174   if (java_bc() == Bytecodes::_checkcast ||
2175       java_bc() == Bytecodes::_instanceof ||
2176       java_bc() == Bytecodes::_aastore) {
2177     ciProfileData* data = method()->method_data()->bci_to_data(bci());
2178     bool maybe_null = data == NULL ? true : data->as_BitData()->null_seen();
2179   }
2180   return record_profile_for_speculation(n, exact_kls, maybe_null);
2181   return n;
2182 }
2183 
2184 /**
2185  * Record profiling data from argument profiling at an invoke with the
2186  * type system so that it can propagate it (speculation)
2187  *
2188  * @param dest_method  target method for the call
2189  * @param bc           what invoke bytecode is this?
2190  */
2191 void GraphKit::record_profiled_arguments_for_speculation(ciMethod* dest_method, Bytecodes::Code bc) {
2192   if (!UseTypeSpeculation) {
2193     return;
2194   }
2195   const TypeFunc* tf    = TypeFunc::make(dest_method);
2196   int             nargs = tf->domain()->cnt() - TypeFunc::Parms;
2197   int skip = Bytecodes::has_receiver(bc) ? 1 : 0;
2198   for (int j = skip, i = 0; j < nargs && i < TypeProfileArgsLimit; j++) {
2199     const Type *targ = tf->domain()->field_at(j + TypeFunc::Parms);
2200     if (targ->basic_type() == T_OBJECT || targ->basic_type() == T_ARRAY) {
2201       bool maybe_null = true;
2202       ciKlass* better_type = NULL;
2203       if (method()->argument_profiled_type(bci(), i, better_type, maybe_null)) {
2204         record_profile_for_speculation(argument(j), better_type, maybe_null);
2205       }
2206       i++;
2207     }
2208   }
2209 }
2210 
2211 /**
2212  * Record profiling data from parameter profiling at an invoke with
2213  * the type system so that it can propagate it (speculation)
2214  */
2215 void GraphKit::record_profiled_parameters_for_speculation() {
2216   if (!UseTypeSpeculation) {
2217     return;
2218   }
2219   for (int i = 0, j = 0; i < method()->arg_size() ; i++) {
2220     if (_gvn.type(local(i))->isa_oopptr()) {
2221       bool maybe_null = true;
2222       ciKlass* better_type = NULL;
2223       if (method()->parameter_profiled_type(j, better_type, maybe_null)) {
2224         record_profile_for_speculation(local(i), better_type, maybe_null);
2225       }
2226       j++;
2227     }
2228   }
2229 }
2230 
2231 /**
2232  * Record profiling data from return value profiling at an invoke with
2233  * the type system so that it can propagate it (speculation)
2234  */
2235 void GraphKit::record_profiled_return_for_speculation() {
2236   if (!UseTypeSpeculation) {
2237     return;
2238   }
2239   bool maybe_null = true;
2240   ciKlass* better_type = NULL;
2241   if (method()->return_profiled_type(bci(), better_type, maybe_null)) {
2242     // If profiling reports a single type for the return value,
2243     // feed it to the type system so it can propagate it as a
2244     // speculative type
2245     record_profile_for_speculation(stack(sp()-1), better_type, maybe_null);
2246   }
2247 }
2248 
2249 void GraphKit::round_double_result(ciMethod* dest_method) {
2250   // A non-strict method may return a double value which has an extended
2251   // exponent, but this must not be visible in a caller which is 'strict'
2252   // If a strict caller invokes a non-strict callee, round a double result
2253 
2254   BasicType result_type = dest_method->return_type()->basic_type();
2255   assert( method() != NULL, "must have caller context");
2256   if( result_type == T_DOUBLE && method()->is_strict() && !dest_method->is_strict() ) {
2257     // Destination method's return value is on top of stack
2258     // dstore_rounding() does gvn.transform
2259     Node *result = pop_pair();
2260     result = dstore_rounding(result);
2261     push_pair(result);
2262   }
2263 }
2264 
2265 // rounding for strict float precision conformance
2266 Node* GraphKit::precision_rounding(Node* n) {
2267   return UseStrictFP && _method->flags().is_strict()
2268     && UseSSE == 0 && Matcher::strict_fp_requires_explicit_rounding
2269     ? _gvn.transform( new RoundFloatNode(0, n) )
2270     : n;
2271 }
2272 
2273 // rounding for strict double precision conformance
2274 Node* GraphKit::dprecision_rounding(Node *n) {
2275   return UseStrictFP && _method->flags().is_strict()
2276     && UseSSE <= 1 && Matcher::strict_fp_requires_explicit_rounding
2277     ? _gvn.transform( new RoundDoubleNode(0, n) )
2278     : n;
2279 }
2280 
2281 // rounding for non-strict double stores
2282 Node* GraphKit::dstore_rounding(Node* n) {
2283   return Matcher::strict_fp_requires_explicit_rounding
2284     && UseSSE <= 1
2285     ? _gvn.transform( new RoundDoubleNode(0, n) )
2286     : n;
2287 }
2288 
2289 //=============================================================================
2290 // Generate a fast path/slow path idiom.  Graph looks like:
2291 // [foo] indicates that 'foo' is a parameter
2292 //
2293 //              [in]     NULL
2294 //                 \    /
2295 //                  CmpP
2296 //                  Bool ne
2297 //                   If
2298 //                  /  \
2299 //              True    False-<2>
2300 //              / |
2301 //             /  cast_not_null
2302 //           Load  |    |   ^
2303 //        [fast_test]   |   |
2304 // gvn to   opt_test    |   |
2305 //          /    \      |  <1>
2306 //      True     False  |
2307 //        |         \\  |
2308 //   [slow_call]     \[fast_result]
2309 //    Ctl   Val       \      \
2310 //     |               \      \
2311 //    Catch       <1>   \      \
2312 //   /    \        ^     \      \
2313 //  Ex    No_Ex    |      \      \
2314 //  |       \   \  |       \ <2>  \
2315 //  ...      \  [slow_res] |  |    \   [null_result]
2316 //            \         \--+--+---  |  |
2317 //             \           | /    \ | /
2318 //              --------Region     Phi
2319 //
2320 //=============================================================================
2321 // Code is structured as a series of driver functions all called 'do_XXX' that
2322 // call a set of helper functions.  Helper functions first, then drivers.
2323 
2324 //------------------------------null_check_oop---------------------------------
2325 // Null check oop.  Set null-path control into Region in slot 3.
2326 // Make a cast-not-nullness use the other not-null control.  Return cast.
2327 Node* GraphKit::null_check_oop(Node* value, Node* *null_control,
2328                                bool never_see_null,
2329                                bool safe_for_replace,
2330                                bool speculative) {
2331   // Initial NULL check taken path
2332   (*null_control) = top();
2333   Node* cast = null_check_common(value, T_OBJECT, false, null_control, speculative);
2334 
2335   // Generate uncommon_trap:
2336   if (never_see_null && (*null_control) != top()) {
2337     // If we see an unexpected null at a check-cast we record it and force a
2338     // recompile; the offending check-cast will be compiled to handle NULLs.
2339     // If we see more than one offending BCI, then all checkcasts in the
2340     // method will be compiled to handle NULLs.
2341     PreserveJVMState pjvms(this);
2342     set_control(*null_control);
2343     replace_in_map(value, null());
2344     Deoptimization::DeoptReason reason = Deoptimization::reason_null_check(speculative);
2345     uncommon_trap(reason,
2346                   Deoptimization::Action_make_not_entrant);
2347     (*null_control) = top();    // NULL path is dead
2348   }
2349   if ((*null_control) == top() && safe_for_replace) {
2350     replace_in_map(value, cast);
2351   }
2352 
2353   // Cast away null-ness on the result
2354   return cast;
2355 }
2356 
2357 //------------------------------opt_iff----------------------------------------
2358 // Optimize the fast-check IfNode.  Set the fast-path region slot 2.
2359 // Return slow-path control.
2360 Node* GraphKit::opt_iff(Node* region, Node* iff) {
2361   IfNode *opt_iff = _gvn.transform(iff)->as_If();
2362 
2363   // Fast path taken; set region slot 2
2364   Node *fast_taken = _gvn.transform( new IfFalseNode(opt_iff) );
2365   region->init_req(2,fast_taken); // Capture fast-control
2366 
2367   // Fast path not-taken, i.e. slow path
2368   Node *slow_taken = _gvn.transform( new IfTrueNode(opt_iff) );
2369   return slow_taken;
2370 }
2371 
2372 //-----------------------------make_runtime_call-------------------------------
2373 Node* GraphKit::make_runtime_call(int flags,
2374                                   const TypeFunc* call_type, address call_addr,
2375                                   const char* call_name,
2376                                   const TypePtr* adr_type,
2377                                   // The following parms are all optional.
2378                                   // The first NULL ends the list.
2379                                   Node* parm0, Node* parm1,
2380                                   Node* parm2, Node* parm3,
2381                                   Node* parm4, Node* parm5,
2382                                   Node* parm6, Node* parm7) {
2383   // Slow-path call
2384   bool is_leaf = !(flags & RC_NO_LEAF);
2385   bool has_io  = (!is_leaf && !(flags & RC_NO_IO));
2386   if (call_name == NULL) {
2387     assert(!is_leaf, "must supply name for leaf");
2388     call_name = OptoRuntime::stub_name(call_addr);
2389   }
2390   CallNode* call;
2391   if (!is_leaf) {
2392     call = new CallStaticJavaNode(call_type, call_addr, call_name,
2393                                            bci(), adr_type);
2394   } else if (flags & RC_NO_FP) {
2395     call = new CallLeafNoFPNode(call_type, call_addr, call_name, adr_type);
2396   } else {
2397     call = new CallLeafNode(call_type, call_addr, call_name, adr_type);
2398   }
2399 
2400   // The following is similar to set_edges_for_java_call,
2401   // except that the memory effects of the call are restricted to AliasIdxRaw.
2402 
2403   // Slow path call has no side-effects, uses few values
2404   bool wide_in  = !(flags & RC_NARROW_MEM);
2405   bool wide_out = (C->get_alias_index(adr_type) == Compile::AliasIdxBot);
2406 
2407   Node* prev_mem = NULL;
2408   if (wide_in) {
2409     prev_mem = set_predefined_input_for_runtime_call(call);
2410   } else {
2411     assert(!wide_out, "narrow in => narrow out");
2412     Node* narrow_mem = memory(adr_type);
2413     prev_mem = reset_memory();
2414     map()->set_memory(narrow_mem);
2415     set_predefined_input_for_runtime_call(call);
2416   }
2417 
2418   // Hook each parm in order.  Stop looking at the first NULL.
2419   if (parm0 != NULL) { call->init_req(TypeFunc::Parms+0, parm0);
2420   if (parm1 != NULL) { call->init_req(TypeFunc::Parms+1, parm1);
2421   if (parm2 != NULL) { call->init_req(TypeFunc::Parms+2, parm2);
2422   if (parm3 != NULL) { call->init_req(TypeFunc::Parms+3, parm3);
2423   if (parm4 != NULL) { call->init_req(TypeFunc::Parms+4, parm4);
2424   if (parm5 != NULL) { call->init_req(TypeFunc::Parms+5, parm5);
2425   if (parm6 != NULL) { call->init_req(TypeFunc::Parms+6, parm6);
2426   if (parm7 != NULL) { call->init_req(TypeFunc::Parms+7, parm7);
2427     /* close each nested if ===> */  } } } } } } } }
2428   assert(call->in(call->req()-1) != NULL, "must initialize all parms");
2429 
2430   if (!is_leaf) {
2431     // Non-leaves can block and take safepoints:
2432     add_safepoint_edges(call, ((flags & RC_MUST_THROW) != 0));
2433   }
2434   // Non-leaves can throw exceptions:
2435   if (has_io) {
2436     call->set_req(TypeFunc::I_O, i_o());
2437   }
2438 
2439   if (flags & RC_UNCOMMON) {
2440     // Set the count to a tiny probability.  Cf. Estimate_Block_Frequency.
2441     // (An "if" probability corresponds roughly to an unconditional count.
2442     // Sort of.)
2443     call->set_cnt(PROB_UNLIKELY_MAG(4));
2444   }
2445 
2446   Node* c = _gvn.transform(call);
2447   assert(c == call, "cannot disappear");
2448 
2449   if (wide_out) {
2450     // Slow path call has full side-effects.
2451     set_predefined_output_for_runtime_call(call);
2452   } else {
2453     // Slow path call has few side-effects, and/or sets few values.
2454     set_predefined_output_for_runtime_call(call, prev_mem, adr_type);
2455   }
2456 
2457   if (has_io) {
2458     set_i_o(_gvn.transform(new ProjNode(call, TypeFunc::I_O)));
2459   }
2460   return call;
2461 
2462 }
2463 
2464 //------------------------------merge_memory-----------------------------------
2465 // Merge memory from one path into the current memory state.
2466 void GraphKit::merge_memory(Node* new_mem, Node* region, int new_path) {
2467   for (MergeMemStream mms(merged_memory(), new_mem->as_MergeMem()); mms.next_non_empty2(); ) {
2468     Node* old_slice = mms.force_memory();
2469     Node* new_slice = mms.memory2();
2470     if (old_slice != new_slice) {
2471       PhiNode* phi;
2472       if (old_slice->is_Phi() && old_slice->as_Phi()->region() == region) {
2473         if (mms.is_empty()) {
2474           // clone base memory Phi's inputs for this memory slice
2475           assert(old_slice == mms.base_memory(), "sanity");
2476           phi = PhiNode::make(region, NULL, Type::MEMORY, mms.adr_type(C));
2477           _gvn.set_type(phi, Type::MEMORY);
2478           for (uint i = 1; i < phi->req(); i++) {
2479             phi->init_req(i, old_slice->in(i));
2480           }
2481         } else {
2482           phi = old_slice->as_Phi(); // Phi was generated already
2483         }
2484       } else {
2485         phi = PhiNode::make(region, old_slice, Type::MEMORY, mms.adr_type(C));
2486         _gvn.set_type(phi, Type::MEMORY);
2487       }
2488       phi->set_req(new_path, new_slice);
2489       mms.set_memory(phi);
2490     }
2491   }
2492 }
2493 
2494 //------------------------------make_slow_call_ex------------------------------
2495 // Make the exception handler hookups for the slow call
2496 void GraphKit::make_slow_call_ex(Node* call, ciInstanceKlass* ex_klass, bool separate_io_proj, bool deoptimize) {
2497   if (stopped())  return;
2498 
2499   // Make a catch node with just two handlers:  fall-through and catch-all
2500   Node* i_o  = _gvn.transform( new ProjNode(call, TypeFunc::I_O, separate_io_proj) );
2501   Node* catc = _gvn.transform( new CatchNode(control(), i_o, 2) );
2502   Node* norm = _gvn.transform( new CatchProjNode(catc, CatchProjNode::fall_through_index, CatchProjNode::no_handler_bci) );
2503   Node* excp = _gvn.transform( new CatchProjNode(catc, CatchProjNode::catch_all_index,    CatchProjNode::no_handler_bci) );
2504 
2505   { PreserveJVMState pjvms(this);
2506     set_control(excp);
2507     set_i_o(i_o);
2508 
2509     if (excp != top()) {
2510       if (deoptimize) {
2511         // Deoptimize if an exception is caught. Don't construct exception state in this case.
2512         uncommon_trap(Deoptimization::Reason_unhandled,
2513                       Deoptimization::Action_none);
2514       } else {
2515         // Create an exception state also.
2516         // Use an exact type if the caller has specified a specific exception.
2517         const Type* ex_type = TypeOopPtr::make_from_klass_unique(ex_klass)->cast_to_ptr_type(TypePtr::NotNull);
2518         Node*       ex_oop  = new CreateExNode(ex_type, control(), i_o);
2519         add_exception_state(make_exception_state(_gvn.transform(ex_oop)));
2520       }
2521     }
2522   }
2523 
2524   // Get the no-exception control from the CatchNode.
2525   set_control(norm);
2526 }
2527 
2528 static IfNode* gen_subtype_check_compare(Node* ctrl, Node* in1, Node* in2, BoolTest::mask test, float p, PhaseGVN* gvn, BasicType bt) {
2529   Node* cmp = NULL;
2530   switch(bt) {
2531   case T_INT: cmp = new CmpINode(in1, in2); break;
2532   case T_ADDRESS: cmp = new CmpPNode(in1, in2); break;
2533   default: fatal(err_msg("unexpected comparison type %s", type2name(bt)));
2534   }
2535   gvn->transform(cmp);
2536   Node* bol = gvn->transform(new BoolNode(cmp, test));
2537   IfNode* iff = new IfNode(ctrl, bol, p, COUNT_UNKNOWN);
2538   gvn->transform(iff);
2539   if (!bol->is_Con()) gvn->record_for_igvn(iff);
2540   return iff;
2541 }
2542 
2543 
2544 //-------------------------------gen_subtype_check-----------------------------
2545 // Generate a subtyping check.  Takes as input the subtype and supertype.
2546 // Returns 2 values: sets the default control() to the true path and returns
2547 // the false path.  Only reads invariant memory; sets no (visible) memory.
2548 // The PartialSubtypeCheckNode sets the hidden 1-word cache in the encoding
2549 // but that's not exposed to the optimizer.  This call also doesn't take in an
2550 // Object; if you wish to check an Object you need to load the Object's class
2551 // prior to coming here.
2552 Node* Phase::gen_subtype_check(Node* subklass, Node* superklass, Node** ctrl, MergeMemNode* mem, PhaseGVN* gvn) {
2553   Compile* C = gvn->C;
2554   // Fast check for identical types, perhaps identical constants.
2555   // The types can even be identical non-constants, in cases
2556   // involving Array.newInstance, Object.clone, etc.
2557   if (subklass == superklass)
2558     return C->top();             // false path is dead; no test needed.
2559 
2560   if (gvn->type(superklass)->singleton()) {
2561     ciKlass* superk = gvn->type(superklass)->is_klassptr()->klass();
2562     ciKlass* subk   = gvn->type(subklass)->is_klassptr()->klass();
2563 
2564     // In the common case of an exact superklass, try to fold up the
2565     // test before generating code.  You may ask, why not just generate
2566     // the code and then let it fold up?  The answer is that the generated
2567     // code will necessarily include null checks, which do not always
2568     // completely fold away.  If they are also needless, then they turn
2569     // into a performance loss.  Example:
2570     //    Foo[] fa = blah(); Foo x = fa[0]; fa[1] = x;
2571     // Here, the type of 'fa' is often exact, so the store check
2572     // of fa[1]=x will fold up, without testing the nullness of x.
2573     switch (C->static_subtype_check(superk, subk)) {
2574     case Compile::SSC_always_false:
2575       {
2576         Node* always_fail = *ctrl;
2577         *ctrl = gvn->C->top();
2578         return always_fail;
2579       }
2580     case Compile::SSC_always_true:
2581       return C->top();
2582     case Compile::SSC_easy_test:
2583       {
2584         // Just do a direct pointer compare and be done.
2585         IfNode* iff = gen_subtype_check_compare(*ctrl, subklass, superklass, BoolTest::eq, PROB_STATIC_FREQUENT, gvn, T_ADDRESS);
2586         *ctrl = gvn->transform(new IfTrueNode(iff));
2587         return gvn->transform(new IfFalseNode(iff));
2588       }
2589     case Compile::SSC_full_test:
2590       break;
2591     default:
2592       ShouldNotReachHere();
2593     }
2594   }
2595 
2596   // %%% Possible further optimization:  Even if the superklass is not exact,
2597   // if the subklass is the unique subtype of the superklass, the check
2598   // will always succeed.  We could leave a dependency behind to ensure this.
2599 
2600   // First load the super-klass's check-offset
2601   Node *p1 = gvn->transform(new AddPNode(superklass, superklass, gvn->MakeConX(in_bytes(Klass::super_check_offset_offset()))));
2602   Node* m = mem->memory_at(C->get_alias_index(gvn->type(p1)->is_ptr()));
2603   Node *chk_off = gvn->transform(new LoadINode(NULL, m, p1, gvn->type(p1)->is_ptr(), TypeInt::INT, MemNode::unordered));
2604   int cacheoff_con = in_bytes(Klass::secondary_super_cache_offset());
2605   bool might_be_cache = (gvn->find_int_con(chk_off, cacheoff_con) == cacheoff_con);
2606 
2607   // Load from the sub-klass's super-class display list, or a 1-word cache of
2608   // the secondary superclass list, or a failing value with a sentinel offset
2609   // if the super-klass is an interface or exceptionally deep in the Java
2610   // hierarchy and we have to scan the secondary superclass list the hard way.
2611   // Worst-case type is a little odd: NULL is allowed as a result (usually
2612   // klass loads can never produce a NULL).
2613   Node *chk_off_X = chk_off;
2614 #ifdef _LP64
2615   chk_off_X = gvn->transform(new ConvI2LNode(chk_off_X));
2616 #endif
2617   Node *p2 = gvn->transform(new AddPNode(subklass,subklass,chk_off_X));
2618   // For some types like interfaces the following loadKlass is from a 1-word
2619   // cache which is mutable so can't use immutable memory.  Other
2620   // types load from the super-class display table which is immutable.
2621   m = mem->memory_at(C->get_alias_index(gvn->type(p2)->is_ptr()));
2622   Node *kmem = might_be_cache ? m : C->immutable_memory();
2623   Node *nkls = gvn->transform(LoadKlassNode::make(*gvn, NULL, kmem, p2, gvn->type(p2)->is_ptr(), TypeKlassPtr::OBJECT_OR_NULL));
2624 
2625   // Compile speed common case: ARE a subtype and we canNOT fail
2626   if( superklass == nkls )
2627     return C->top();             // false path is dead; no test needed.
2628 
2629   // See if we get an immediate positive hit.  Happens roughly 83% of the
2630   // time.  Test to see if the value loaded just previously from the subklass
2631   // is exactly the superklass.
2632   IfNode *iff1 = gen_subtype_check_compare(*ctrl, superklass, nkls, BoolTest::eq, PROB_LIKELY(0.83f), gvn, T_ADDRESS);
2633   Node *iftrue1 = gvn->transform( new IfTrueNode (iff1));
2634   *ctrl = gvn->transform(new IfFalseNode(iff1));
2635 
2636   // Compile speed common case: Check for being deterministic right now.  If
2637   // chk_off is a constant and not equal to cacheoff then we are NOT a
2638   // subklass.  In this case we need exactly the 1 test above and we can
2639   // return those results immediately.
2640   if (!might_be_cache) {
2641     Node* not_subtype_ctrl = *ctrl;
2642     *ctrl = iftrue1; // We need exactly the 1 test above
2643     return not_subtype_ctrl;
2644   }
2645 
2646   // Gather the various success & failures here
2647   RegionNode *r_ok_subtype = new RegionNode(4);
2648   gvn->record_for_igvn(r_ok_subtype);
2649   RegionNode *r_not_subtype = new RegionNode(3);
2650   gvn->record_for_igvn(r_not_subtype);
2651 
2652   r_ok_subtype->init_req(1, iftrue1);
2653 
2654   // Check for immediate negative hit.  Happens roughly 11% of the time (which
2655   // is roughly 63% of the remaining cases).  Test to see if the loaded
2656   // check-offset points into the subklass display list or the 1-element
2657   // cache.  If it points to the display (and NOT the cache) and the display
2658   // missed then it's not a subtype.
2659   Node *cacheoff = gvn->intcon(cacheoff_con);
2660   IfNode *iff2 = gen_subtype_check_compare(*ctrl, chk_off, cacheoff, BoolTest::ne, PROB_LIKELY(0.63f), gvn, T_INT);
2661   r_not_subtype->init_req(1, gvn->transform(new IfTrueNode (iff2)));
2662   *ctrl = gvn->transform(new IfFalseNode(iff2));
2663 
2664   // Check for self.  Very rare to get here, but it is taken 1/3 the time.
2665   // No performance impact (too rare) but allows sharing of secondary arrays
2666   // which has some footprint reduction.
2667   IfNode *iff3 = gen_subtype_check_compare(*ctrl, subklass, superklass, BoolTest::eq, PROB_LIKELY(0.36f), gvn, T_ADDRESS);
2668   r_ok_subtype->init_req(2, gvn->transform(new IfTrueNode(iff3)));
2669   *ctrl = gvn->transform(new IfFalseNode(iff3));
2670 
2671   // -- Roads not taken here: --
2672   // We could also have chosen to perform the self-check at the beginning
2673   // of this code sequence, as the assembler does.  This would not pay off
2674   // the same way, since the optimizer, unlike the assembler, can perform
2675   // static type analysis to fold away many successful self-checks.
2676   // Non-foldable self checks work better here in second position, because
2677   // the initial primary superclass check subsumes a self-check for most
2678   // types.  An exception would be a secondary type like array-of-interface,
2679   // which does not appear in its own primary supertype display.
2680   // Finally, we could have chosen to move the self-check into the
2681   // PartialSubtypeCheckNode, and from there out-of-line in a platform
2682   // dependent manner.  But it is worthwhile to have the check here,
2683   // where it can be perhaps be optimized.  The cost in code space is
2684   // small (register compare, branch).
2685 
2686   // Now do a linear scan of the secondary super-klass array.  Again, no real
2687   // performance impact (too rare) but it's gotta be done.
2688   // Since the code is rarely used, there is no penalty for moving it
2689   // out of line, and it can only improve I-cache density.
2690   // The decision to inline or out-of-line this final check is platform
2691   // dependent, and is found in the AD file definition of PartialSubtypeCheck.
2692   Node* psc = gvn->transform(
2693     new PartialSubtypeCheckNode(*ctrl, subklass, superklass));
2694 
2695   IfNode *iff4 = gen_subtype_check_compare(*ctrl, psc, gvn->zerocon(T_OBJECT), BoolTest::ne, PROB_FAIR, gvn, T_ADDRESS);
2696   r_not_subtype->init_req(2, gvn->transform(new IfTrueNode (iff4)));
2697   r_ok_subtype ->init_req(3, gvn->transform(new IfFalseNode(iff4)));
2698 
2699   // Return false path; set default control to true path.
2700   *ctrl = gvn->transform(r_ok_subtype);
2701   return gvn->transform(r_not_subtype);
2702 }
2703 
2704 // Profile-driven exact type check:
2705 Node* GraphKit::type_check_receiver(Node* receiver, ciKlass* klass,
2706                                     float prob,
2707                                     Node* *casted_receiver) {
2708   const TypeKlassPtr* tklass = TypeKlassPtr::make(klass);
2709   Node* recv_klass = load_object_klass(receiver);
2710   Node* want_klass = makecon(tklass);
2711   Node* cmp = _gvn.transform( new CmpPNode(recv_klass, want_klass) );
2712   Node* bol = _gvn.transform( new BoolNode(cmp, BoolTest::eq) );
2713   IfNode* iff = create_and_xform_if(control(), bol, prob, COUNT_UNKNOWN);
2714   set_control( _gvn.transform( new IfTrueNode (iff) ));
2715   Node* fail = _gvn.transform( new IfFalseNode(iff) );
2716 
2717   const TypeOopPtr* recv_xtype = tklass->as_instance_type();
2718   assert(recv_xtype->klass_is_exact(), "");
2719 
2720   // Subsume downstream occurrences of receiver with a cast to
2721   // recv_xtype, since now we know what the type will be.
2722   Node* cast = new CheckCastPPNode(control(), receiver, recv_xtype);
2723   (*casted_receiver) = _gvn.transform(cast);
2724   // (User must make the replace_in_map call.)
2725 
2726   return fail;
2727 }
2728 
2729 
2730 //------------------------------seems_never_null-------------------------------
2731 // Use null_seen information if it is available from the profile.
2732 // If we see an unexpected null at a type check we record it and force a
2733 // recompile; the offending check will be recompiled to handle NULLs.
2734 // If we see several offending BCIs, then all checks in the
2735 // method will be recompiled.
2736 bool GraphKit::seems_never_null(Node* obj, ciProfileData* data, bool& speculating) {
2737   speculating = !_gvn.type(obj)->speculative_maybe_null();
2738   Deoptimization::DeoptReason reason = Deoptimization::reason_null_check(speculating);
2739   if (UncommonNullCast               // Cutout for this technique
2740       && obj != null()               // And not the -Xcomp stupid case?
2741       && !too_many_traps(reason)
2742       ) {
2743     if (speculating) {
2744       return true;
2745     }
2746     if (data == NULL)
2747       // Edge case:  no mature data.  Be optimistic here.
2748       return true;
2749     // If the profile has not seen a null, assume it won't happen.
2750     assert(java_bc() == Bytecodes::_checkcast ||
2751            java_bc() == Bytecodes::_instanceof ||
2752            java_bc() == Bytecodes::_aastore, "MDO must collect null_seen bit here");
2753     return !data->as_BitData()->null_seen();
2754   }
2755   speculating = false;
2756   return false;
2757 }
2758 
2759 //------------------------maybe_cast_profiled_receiver-------------------------
2760 // If the profile has seen exactly one type, narrow to exactly that type.
2761 // Subsequent type checks will always fold up.
2762 Node* GraphKit::maybe_cast_profiled_receiver(Node* not_null_obj,
2763                                              ciKlass* require_klass,
2764                                              ciKlass* spec_klass,
2765                                              bool safe_for_replace) {
2766   if (!UseTypeProfile || !TypeProfileCasts) return NULL;
2767 
2768   Deoptimization::DeoptReason reason = Deoptimization::reason_class_check(spec_klass != NULL);
2769 
2770   // Make sure we haven't already deoptimized from this tactic.
2771   if (too_many_traps(reason) || too_many_recompiles(reason))
2772     return NULL;
2773 
2774   // (No, this isn't a call, but it's enough like a virtual call
2775   // to use the same ciMethod accessor to get the profile info...)
2776   // If we have a speculative type use it instead of profiling (which
2777   // may not help us)
2778   ciKlass* exact_kls = spec_klass == NULL ? profile_has_unique_klass() : spec_klass;
2779   if (exact_kls != NULL) {// no cast failures here
2780     if (require_klass == NULL ||
2781         C->static_subtype_check(require_klass, exact_kls) == Compile::SSC_always_true) {
2782       // If we narrow the type to match what the type profile sees or
2783       // the speculative type, we can then remove the rest of the
2784       // cast.
2785       // This is a win, even if the exact_kls is very specific,
2786       // because downstream operations, such as method calls,
2787       // will often benefit from the sharper type.
2788       Node* exact_obj = not_null_obj; // will get updated in place...
2789       Node* slow_ctl  = type_check_receiver(exact_obj, exact_kls, 1.0,
2790                                             &exact_obj);
2791       { PreserveJVMState pjvms(this);
2792         set_control(slow_ctl);
2793         uncommon_trap_exact(reason, Deoptimization::Action_maybe_recompile);
2794       }
2795       if (safe_for_replace) {
2796         replace_in_map(not_null_obj, exact_obj);
2797       }
2798       return exact_obj;
2799     }
2800     // assert(ssc == Compile::SSC_always_true)... except maybe the profile lied to us.
2801   }
2802 
2803   return NULL;
2804 }
2805 
2806 /**
2807  * Cast obj to type and emit guard unless we had too many traps here
2808  * already
2809  *
2810  * @param obj       node being casted
2811  * @param type      type to cast the node to
2812  * @param not_null  true if we know node cannot be null
2813  */
2814 Node* GraphKit::maybe_cast_profiled_obj(Node* obj,
2815                                         ciKlass* type,
2816                                         bool not_null,
2817                                         SafePointNode* sfpt) {
2818   // type == NULL if profiling tells us this object is always null
2819   if (type != NULL) {
2820     Deoptimization::DeoptReason class_reason = Deoptimization::Reason_speculate_class_check;
2821     Deoptimization::DeoptReason null_reason = Deoptimization::Reason_speculate_null_check;
2822     ciMethod* trap_method = (sfpt == NULL) ? method() : sfpt->jvms()->method();
2823     int trap_bci = (sfpt == NULL) ? bci() : sfpt->jvms()->bci();
2824 
2825     if (!too_many_traps(null_reason) && !too_many_recompiles(null_reason) &&
2826         !C->too_many_traps(trap_method, trap_bci, class_reason) &&
2827         !C->too_many_recompiles(trap_method, trap_bci, class_reason)) {
2828       Node* not_null_obj = NULL;
2829       // not_null is true if we know the object is not null and
2830       // there's no need for a null check
2831       if (!not_null) {
2832         Node* null_ctl = top();
2833         not_null_obj = null_check_oop(obj, &null_ctl, true, true, true);
2834         assert(null_ctl->is_top(), "no null control here");
2835       } else {
2836         not_null_obj = obj;
2837       }
2838 
2839       Node* exact_obj = not_null_obj;
2840       ciKlass* exact_kls = type;
2841       Node* slow_ctl  = type_check_receiver(exact_obj, exact_kls, 1.0,
2842                                             &exact_obj);
2843       if (sfpt != NULL) {
2844         GraphKit kit(sfpt->jvms());
2845         PreserveJVMState pjvms(&kit);
2846         kit.set_control(slow_ctl);
2847         kit.uncommon_trap_exact(class_reason, Deoptimization::Action_maybe_recompile);
2848       } else {
2849         PreserveJVMState pjvms(this);
2850         set_control(slow_ctl);
2851         uncommon_trap_exact(class_reason, Deoptimization::Action_maybe_recompile);
2852       }
2853       replace_in_map(not_null_obj, exact_obj);
2854       obj = exact_obj;
2855     }
2856   } else {
2857     if (!too_many_traps(Deoptimization::Reason_null_assert) &&
2858         !too_many_recompiles(Deoptimization::Reason_null_assert)) {
2859       Node* exact_obj = null_assert(obj);
2860       replace_in_map(obj, exact_obj);
2861       obj = exact_obj;
2862     }
2863   }
2864   return obj;
2865 }
2866 
2867 //-------------------------------gen_instanceof--------------------------------
2868 // Generate an instance-of idiom.  Used by both the instance-of bytecode
2869 // and the reflective instance-of call.
2870 Node* GraphKit::gen_instanceof(Node* obj, Node* superklass, bool safe_for_replace) {
2871   kill_dead_locals();           // Benefit all the uncommon traps
2872   assert( !stopped(), "dead parse path should be checked in callers" );
2873   assert(!TypePtr::NULL_PTR->higher_equal(_gvn.type(superklass)->is_klassptr()),
2874          "must check for not-null not-dead klass in callers");
2875 
2876   // Make the merge point
2877   enum { _obj_path = 1, _fail_path, _null_path, PATH_LIMIT };
2878   RegionNode* region = new RegionNode(PATH_LIMIT);
2879   Node*       phi    = new PhiNode(region, TypeInt::BOOL);
2880   C->set_has_split_ifs(true); // Has chance for split-if optimization
2881 
2882   ciProfileData* data = NULL;
2883   if (java_bc() == Bytecodes::_instanceof) {  // Only for the bytecode
2884     data = method()->method_data()->bci_to_data(bci());
2885   }
2886   bool speculative_not_null = false;
2887   bool never_see_null = (ProfileDynamicTypes  // aggressive use of profile
2888                          && seems_never_null(obj, data, speculative_not_null));
2889 
2890   // Null check; get casted pointer; set region slot 3
2891   Node* null_ctl = top();
2892   Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null, safe_for_replace, speculative_not_null);
2893 
2894   // If not_null_obj is dead, only null-path is taken
2895   if (stopped()) {              // Doing instance-of on a NULL?
2896     set_control(null_ctl);
2897     return intcon(0);
2898   }
2899   region->init_req(_null_path, null_ctl);
2900   phi   ->init_req(_null_path, intcon(0)); // Set null path value
2901   if (null_ctl == top()) {
2902     // Do this eagerly, so that pattern matches like is_diamond_phi
2903     // will work even during parsing.
2904     assert(_null_path == PATH_LIMIT-1, "delete last");
2905     region->del_req(_null_path);
2906     phi   ->del_req(_null_path);
2907   }
2908 
2909   // Do we know the type check always succeed?
2910   bool known_statically = false;
2911   if (_gvn.type(superklass)->singleton()) {
2912     ciKlass* superk = _gvn.type(superklass)->is_klassptr()->klass();
2913     ciKlass* subk = _gvn.type(obj)->is_oopptr()->klass();
2914     if (subk != NULL && subk->is_loaded()) {
2915       int static_res = C->static_subtype_check(superk, subk);
2916       known_statically = (static_res == Compile::SSC_always_true || static_res == Compile::SSC_always_false);
2917     }
2918   }
2919 
2920   if (known_statically && UseTypeSpeculation) {
2921     // If we know the type check always succeeds then we don't use the
2922     // profiling data at this bytecode. Don't lose it, feed it to the
2923     // type system as a speculative type.
2924     not_null_obj = record_profiled_receiver_for_speculation(not_null_obj);
2925   } else {
2926     const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
2927     // We may not have profiling here or it may not help us. If we
2928     // have a speculative type use it to perform an exact cast.
2929     ciKlass* spec_obj_type = obj_type->speculative_type();
2930     if (spec_obj_type != NULL || (ProfileDynamicTypes && data != NULL)) {
2931       Node* cast_obj = maybe_cast_profiled_receiver(not_null_obj, NULL, spec_obj_type, safe_for_replace);
2932       if (stopped()) {            // Profile disagrees with this path.
2933         set_control(null_ctl);    // Null is the only remaining possibility.
2934         return intcon(0);
2935       }
2936       if (cast_obj != NULL) {
2937         not_null_obj = cast_obj;
2938       }
2939     }
2940   }
2941 
2942   // Load the object's klass
2943   Node* obj_klass = load_object_klass(not_null_obj);
2944 
2945   // Generate the subtype check
2946   Node* not_subtype_ctrl = gen_subtype_check(obj_klass, superklass);
2947 
2948   // Plug in the success path to the general merge in slot 1.
2949   region->init_req(_obj_path, control());
2950   phi   ->init_req(_obj_path, intcon(1));
2951 
2952   // Plug in the failing path to the general merge in slot 2.
2953   region->init_req(_fail_path, not_subtype_ctrl);
2954   phi   ->init_req(_fail_path, intcon(0));
2955 
2956   // Return final merged results
2957   set_control( _gvn.transform(region) );
2958   record_for_igvn(region);
2959   return _gvn.transform(phi);
2960 }
2961 
2962 //-------------------------------gen_checkcast---------------------------------
2963 // Generate a checkcast idiom.  Used by both the checkcast bytecode and the
2964 // array store bytecode.  Stack must be as-if BEFORE doing the bytecode so the
2965 // uncommon-trap paths work.  Adjust stack after this call.
2966 // If failure_control is supplied and not null, it is filled in with
2967 // the control edge for the cast failure.  Otherwise, an appropriate
2968 // uncommon trap or exception is thrown.
2969 Node* GraphKit::gen_checkcast(Node *obj, Node* superklass,
2970                               Node* *failure_control) {
2971   kill_dead_locals();           // Benefit all the uncommon traps
2972   const TypeKlassPtr *tk = _gvn.type(superklass)->is_klassptr();
2973   const Type *toop = TypeOopPtr::make_from_klass(tk->klass());
2974 
2975   // Fast cutout:  Check the case that the cast is vacuously true.
2976   // This detects the common cases where the test will short-circuit
2977   // away completely.  We do this before we perform the null check,
2978   // because if the test is going to turn into zero code, we don't
2979   // want a residual null check left around.  (Causes a slowdown,
2980   // for example, in some objArray manipulations, such as a[i]=a[j].)
2981   if (tk->singleton()) {
2982     const TypeOopPtr* objtp = _gvn.type(obj)->isa_oopptr();
2983     if (objtp != NULL && objtp->klass() != NULL) {
2984       switch (C->static_subtype_check(tk->klass(), objtp->klass())) {
2985       case Compile::SSC_always_true:
2986         // If we know the type check always succeed then we don't use
2987         // the profiling data at this bytecode. Don't lose it, feed it
2988         // to the type system as a speculative type.
2989         return record_profiled_receiver_for_speculation(obj);
2990       case Compile::SSC_always_false:
2991         // It needs a null check because a null will *pass* the cast check.
2992         // A non-null value will always produce an exception.
2993         return null_assert(obj);
2994       }
2995     }
2996   }
2997 
2998   ciProfileData* data = NULL;
2999   bool safe_for_replace = false;
3000   if (failure_control == NULL) {        // use MDO in regular case only
3001     assert(java_bc() == Bytecodes::_aastore ||
3002            java_bc() == Bytecodes::_checkcast,
3003            "interpreter profiles type checks only for these BCs");
3004     data = method()->method_data()->bci_to_data(bci());
3005     safe_for_replace = true;
3006   }
3007 
3008   // Make the merge point
3009   enum { _obj_path = 1, _null_path, PATH_LIMIT };
3010   RegionNode* region = new RegionNode(PATH_LIMIT);
3011   Node*       phi    = new PhiNode(region, toop);
3012   C->set_has_split_ifs(true); // Has chance for split-if optimization
3013 
3014   // Use null-cast information if it is available
3015   bool speculative_not_null = false;
3016   bool never_see_null = ((failure_control == NULL)  // regular case only
3017                          && seems_never_null(obj, data, speculative_not_null));
3018 
3019   // Null check; get casted pointer; set region slot 3
3020   Node* null_ctl = top();
3021   Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null, safe_for_replace, speculative_not_null);
3022 
3023   // If not_null_obj is dead, only null-path is taken
3024   if (stopped()) {              // Doing instance-of on a NULL?
3025     set_control(null_ctl);
3026     return null();
3027   }
3028   region->init_req(_null_path, null_ctl);
3029   phi   ->init_req(_null_path, null());  // Set null path value
3030   if (null_ctl == top()) {
3031     // Do this eagerly, so that pattern matches like is_diamond_phi
3032     // will work even during parsing.
3033     assert(_null_path == PATH_LIMIT-1, "delete last");
3034     region->del_req(_null_path);
3035     phi   ->del_req(_null_path);
3036   }
3037 
3038   Node* cast_obj = NULL;
3039   if (tk->klass_is_exact()) {
3040     // The following optimization tries to statically cast the speculative type of the object
3041     // (for example obtained during profiling) to the type of the superklass and then do a
3042     // dynamic check that the type of the object is what we expect. To work correctly
3043     // for checkcast and aastore the type of superklass should be exact.
3044     const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
3045     // We may not have profiling here or it may not help us. If we have
3046     // a speculative type use it to perform an exact cast.
3047     ciKlass* spec_obj_type = obj_type->speculative_type();
3048     if (spec_obj_type != NULL || (data != NULL)) {
3049       cast_obj = maybe_cast_profiled_receiver(not_null_obj, tk->klass(), spec_obj_type, safe_for_replace);
3050       if (cast_obj != NULL) {
3051         if (failure_control != NULL) // failure is now impossible
3052           (*failure_control) = top();
3053         // adjust the type of the phi to the exact klass:
3054         phi->raise_bottom_type(_gvn.type(cast_obj)->meet_speculative(TypePtr::NULL_PTR));
3055       }
3056     }
3057   }
3058 
3059   if (cast_obj == NULL) {
3060     // Load the object's klass
3061     Node* obj_klass = load_object_klass(not_null_obj);
3062 
3063     // Generate the subtype check
3064     Node* not_subtype_ctrl = gen_subtype_check( obj_klass, superklass );
3065 
3066     // Plug in success path into the merge
3067     cast_obj = _gvn.transform(new CheckCastPPNode(control(), not_null_obj, toop));
3068     // Failure path ends in uncommon trap (or may be dead - failure impossible)
3069     if (failure_control == NULL) {
3070       if (not_subtype_ctrl != top()) { // If failure is possible
3071         PreserveJVMState pjvms(this);
3072         set_control(not_subtype_ctrl);
3073         builtin_throw(Deoptimization::Reason_class_check, obj_klass);
3074       }
3075     } else {
3076       (*failure_control) = not_subtype_ctrl;
3077     }
3078   }
3079 
3080   region->init_req(_obj_path, control());
3081   phi   ->init_req(_obj_path, cast_obj);
3082 
3083   // A merge of NULL or Casted-NotNull obj
3084   Node* res = _gvn.transform(phi);
3085 
3086   // Note I do NOT always 'replace_in_map(obj,result)' here.
3087   //  if( tk->klass()->can_be_primary_super()  )
3088     // This means that if I successfully store an Object into an array-of-String
3089     // I 'forget' that the Object is really now known to be a String.  I have to
3090     // do this because we don't have true union types for interfaces - if I store
3091     // a Baz into an array-of-Interface and then tell the optimizer it's an
3092     // Interface, I forget that it's also a Baz and cannot do Baz-like field
3093     // references to it.  FIX THIS WHEN UNION TYPES APPEAR!
3094   //  replace_in_map( obj, res );
3095 
3096   // Return final merged results
3097   set_control( _gvn.transform(region) );
3098   record_for_igvn(region);
3099   return res;
3100 }
3101 
3102 //------------------------------next_monitor-----------------------------------
3103 // What number should be given to the next monitor?
3104 int GraphKit::next_monitor() {
3105   int current = jvms()->monitor_depth()* C->sync_stack_slots();
3106   int next = current + C->sync_stack_slots();
3107   // Keep the toplevel high water mark current:
3108   if (C->fixed_slots() < next)  C->set_fixed_slots(next);
3109   return current;
3110 }
3111 
3112 //------------------------------insert_mem_bar---------------------------------
3113 // Memory barrier to avoid floating things around
3114 // The membar serves as a pinch point between both control and all memory slices.
3115 Node* GraphKit::insert_mem_bar(int opcode, Node* precedent) {
3116   MemBarNode* mb = MemBarNode::make(C, opcode, Compile::AliasIdxBot, precedent);
3117   mb->init_req(TypeFunc::Control, control());
3118   mb->init_req(TypeFunc::Memory,  reset_memory());
3119   Node* membar = _gvn.transform(mb);
3120   set_control(_gvn.transform(new ProjNode(membar, TypeFunc::Control)));
3121   set_all_memory_call(membar);
3122   return membar;
3123 }
3124 
3125 //-------------------------insert_mem_bar_volatile----------------------------
3126 // Memory barrier to avoid floating things around
3127 // The membar serves as a pinch point between both control and memory(alias_idx).
3128 // If you want to make a pinch point on all memory slices, do not use this
3129 // function (even with AliasIdxBot); use insert_mem_bar() instead.
3130 Node* GraphKit::insert_mem_bar_volatile(int opcode, int alias_idx, Node* precedent) {
3131   // When Parse::do_put_xxx updates a volatile field, it appends a series
3132   // of MemBarVolatile nodes, one for *each* volatile field alias category.
3133   // The first membar is on the same memory slice as the field store opcode.
3134   // This forces the membar to follow the store.  (Bug 6500685 broke this.)
3135   // All the other membars (for other volatile slices, including AliasIdxBot,
3136   // which stands for all unknown volatile slices) are control-dependent
3137   // on the first membar.  This prevents later volatile loads or stores
3138   // from sliding up past the just-emitted store.
3139 
3140   MemBarNode* mb = MemBarNode::make(C, opcode, alias_idx, precedent);
3141   mb->set_req(TypeFunc::Control,control());
3142   if (alias_idx == Compile::AliasIdxBot) {
3143     mb->set_req(TypeFunc::Memory, merged_memory()->base_memory());
3144   } else {
3145     assert(!(opcode == Op_Initialize && alias_idx != Compile::AliasIdxRaw), "fix caller");
3146     mb->set_req(TypeFunc::Memory, memory(alias_idx));
3147   }
3148   Node* membar = _gvn.transform(mb);
3149   set_control(_gvn.transform(new ProjNode(membar, TypeFunc::Control)));
3150   if (alias_idx == Compile::AliasIdxBot) {
3151     merged_memory()->set_base_memory(_gvn.transform(new ProjNode(membar, TypeFunc::Memory)));
3152   } else {
3153     set_memory(_gvn.transform(new ProjNode(membar, TypeFunc::Memory)),alias_idx);
3154   }
3155   return membar;
3156 }
3157 
3158 //------------------------------shared_lock------------------------------------
3159 // Emit locking code.
3160 FastLockNode* GraphKit::shared_lock(Node* obj) {
3161   // bci is either a monitorenter bc or InvocationEntryBci
3162   // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
3163   assert(SynchronizationEntryBCI == InvocationEntryBci, "");
3164 
3165   if( !GenerateSynchronizationCode )
3166     return NULL;                // Not locking things?
3167   if (stopped())                // Dead monitor?
3168     return NULL;
3169 
3170   assert(dead_locals_are_killed(), "should kill locals before sync. point");
3171 
3172   // Box the stack location
3173   Node* box = _gvn.transform(new BoxLockNode(next_monitor()));
3174   Node* mem = reset_memory();
3175 
3176   FastLockNode * flock = _gvn.transform(new FastLockNode(0, obj, box) )->as_FastLock();
3177   if (UseBiasedLocking && PrintPreciseBiasedLockingStatistics) {
3178     // Create the counters for this fast lock.
3179     flock->create_lock_counter(sync_jvms()); // sync_jvms used to get current bci
3180   }
3181 
3182   // Create the rtm counters for this fast lock if needed.
3183   flock->create_rtm_lock_counter(sync_jvms()); // sync_jvms used to get current bci
3184 
3185   // Add monitor to debug info for the slow path.  If we block inside the
3186   // slow path and de-opt, we need the monitor hanging around
3187   map()->push_monitor( flock );
3188 
3189   const TypeFunc *tf = LockNode::lock_type();
3190   LockNode *lock = new LockNode(C, tf);
3191 
3192   lock->init_req( TypeFunc::Control, control() );
3193   lock->init_req( TypeFunc::Memory , mem );
3194   lock->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
3195   lock->init_req( TypeFunc::FramePtr, frameptr() );
3196   lock->init_req( TypeFunc::ReturnAdr, top() );
3197 
3198   lock->init_req(TypeFunc::Parms + 0, obj);
3199   lock->init_req(TypeFunc::Parms + 1, box);
3200   lock->init_req(TypeFunc::Parms + 2, flock);
3201   add_safepoint_edges(lock);
3202 
3203   lock = _gvn.transform( lock )->as_Lock();
3204 
3205   // lock has no side-effects, sets few values
3206   set_predefined_output_for_runtime_call(lock, mem, TypeRawPtr::BOTTOM);
3207 
3208   insert_mem_bar(Op_MemBarAcquireLock);
3209 
3210   // Add this to the worklist so that the lock can be eliminated
3211   record_for_igvn(lock);
3212 
3213 #ifndef PRODUCT
3214   if (PrintLockStatistics) {
3215     // Update the counter for this lock.  Don't bother using an atomic
3216     // operation since we don't require absolute accuracy.
3217     lock->create_lock_counter(map()->jvms());
3218     increment_counter(lock->counter()->addr());
3219   }
3220 #endif
3221 
3222   return flock;
3223 }
3224 
3225 
3226 //------------------------------shared_unlock----------------------------------
3227 // Emit unlocking code.
3228 void GraphKit::shared_unlock(Node* box, Node* obj) {
3229   // bci is either a monitorenter bc or InvocationEntryBci
3230   // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
3231   assert(SynchronizationEntryBCI == InvocationEntryBci, "");
3232 
3233   if( !GenerateSynchronizationCode )
3234     return;
3235   if (stopped()) {               // Dead monitor?
3236     map()->pop_monitor();        // Kill monitor from debug info
3237     return;
3238   }
3239 
3240   // Memory barrier to avoid floating things down past the locked region
3241   insert_mem_bar(Op_MemBarReleaseLock);
3242 
3243   const TypeFunc *tf = OptoRuntime::complete_monitor_exit_Type();
3244   UnlockNode *unlock = new UnlockNode(C, tf);
3245   uint raw_idx = Compile::AliasIdxRaw;
3246   unlock->init_req( TypeFunc::Control, control() );
3247   unlock->init_req( TypeFunc::Memory , memory(raw_idx) );
3248   unlock->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
3249   unlock->init_req( TypeFunc::FramePtr, frameptr() );
3250   unlock->init_req( TypeFunc::ReturnAdr, top() );
3251 
3252   unlock->init_req(TypeFunc::Parms + 0, obj);
3253   unlock->init_req(TypeFunc::Parms + 1, box);
3254   unlock = _gvn.transform(unlock)->as_Unlock();
3255 
3256   Node* mem = reset_memory();
3257 
3258   // unlock has no side-effects, sets few values
3259   set_predefined_output_for_runtime_call(unlock, mem, TypeRawPtr::BOTTOM);
3260 
3261   // Kill monitor from debug info
3262   map()->pop_monitor( );
3263 }
3264 
3265 //-------------------------------get_layout_helper-----------------------------
3266 // If the given klass is a constant or known to be an array,
3267 // fetch the constant layout helper value into constant_value
3268 // and return (Node*)NULL.  Otherwise, load the non-constant
3269 // layout helper value, and return the node which represents it.
3270 // This two-faced routine is useful because allocation sites
3271 // almost always feature constant types.
3272 Node* GraphKit::get_layout_helper(Node* klass_node, jint& constant_value) {
3273   const TypeKlassPtr* inst_klass = _gvn.type(klass_node)->isa_klassptr();
3274   if (!StressReflectiveCode && inst_klass != NULL) {
3275     ciKlass* klass = inst_klass->klass();
3276     bool    xklass = inst_klass->klass_is_exact();
3277     if (xklass || klass->is_array_klass()) {
3278       jint lhelper = klass->layout_helper();
3279       if (lhelper != Klass::_lh_neutral_value) {
3280         constant_value = lhelper;
3281         return (Node*) NULL;
3282       }
3283     }
3284   }
3285   constant_value = Klass::_lh_neutral_value;  // put in a known value
3286   Node* lhp = basic_plus_adr(klass_node, klass_node, in_bytes(Klass::layout_helper_offset()));
3287   return make_load(NULL, lhp, TypeInt::INT, T_INT, MemNode::unordered);
3288 }
3289 
3290 // We just put in an allocate/initialize with a big raw-memory effect.
3291 // Hook selected additional alias categories on the initialization.
3292 static void hook_memory_on_init(GraphKit& kit, int alias_idx,
3293                                 MergeMemNode* init_in_merge,
3294                                 Node* init_out_raw) {
3295   DEBUG_ONLY(Node* init_in_raw = init_in_merge->base_memory());
3296   assert(init_in_merge->memory_at(alias_idx) == init_in_raw, "");
3297 
3298   Node* prevmem = kit.memory(alias_idx);
3299   init_in_merge->set_memory_at(alias_idx, prevmem);
3300   kit.set_memory(init_out_raw, alias_idx);
3301 }
3302 
3303 //---------------------------set_output_for_allocation-------------------------
3304 Node* GraphKit::set_output_for_allocation(AllocateNode* alloc,
3305                                           const TypeOopPtr* oop_type,
3306                                           bool deoptimize_on_exception) {
3307   int rawidx = Compile::AliasIdxRaw;
3308   alloc->set_req( TypeFunc::FramePtr, frameptr() );
3309   add_safepoint_edges(alloc);
3310   Node* allocx = _gvn.transform(alloc);
3311   set_control( _gvn.transform(new ProjNode(allocx, TypeFunc::Control) ) );
3312   // create memory projection for i_o
3313   set_memory ( _gvn.transform( new ProjNode(allocx, TypeFunc::Memory, true) ), rawidx );
3314   make_slow_call_ex(allocx, env()->Throwable_klass(), true, deoptimize_on_exception);
3315 
3316   // create a memory projection as for the normal control path
3317   Node* malloc = _gvn.transform(new ProjNode(allocx, TypeFunc::Memory));
3318   set_memory(malloc, rawidx);
3319 
3320   // a normal slow-call doesn't change i_o, but an allocation does
3321   // we create a separate i_o projection for the normal control path
3322   set_i_o(_gvn.transform( new ProjNode(allocx, TypeFunc::I_O, false) ) );
3323   Node* rawoop = _gvn.transform( new ProjNode(allocx, TypeFunc::Parms) );
3324 
3325   // put in an initialization barrier
3326   InitializeNode* init = insert_mem_bar_volatile(Op_Initialize, rawidx,
3327                                                  rawoop)->as_Initialize();
3328   assert(alloc->initialization() == init,  "2-way macro link must work");
3329   assert(init ->allocation()     == alloc, "2-way macro link must work");
3330   {
3331     // Extract memory strands which may participate in the new object's
3332     // initialization, and source them from the new InitializeNode.
3333     // This will allow us to observe initializations when they occur,
3334     // and link them properly (as a group) to the InitializeNode.
3335     assert(init->in(InitializeNode::Memory) == malloc, "");
3336     MergeMemNode* minit_in = MergeMemNode::make(malloc);
3337     init->set_req(InitializeNode::Memory, minit_in);
3338     record_for_igvn(minit_in); // fold it up later, if possible
3339     Node* minit_out = memory(rawidx);
3340     assert(minit_out->is_Proj() && minit_out->in(0) == init, "");
3341     if (oop_type->isa_aryptr()) {
3342       const TypePtr* telemref = oop_type->add_offset(Type::OffsetBot);
3343       int            elemidx  = C->get_alias_index(telemref);
3344       hook_memory_on_init(*this, elemidx, minit_in, minit_out);
3345     } else if (oop_type->isa_instptr()) {
3346       ciInstanceKlass* ik = oop_type->klass()->as_instance_klass();
3347       for (int i = 0, len = ik->nof_nonstatic_fields(); i < len; i++) {
3348         ciField* field = ik->nonstatic_field_at(i);
3349         if (field->offset() >= TrackedInitializationLimit * HeapWordSize)
3350           continue;  // do not bother to track really large numbers of fields
3351         // Find (or create) the alias category for this field:
3352         int fieldidx = C->alias_type(field)->index();
3353         hook_memory_on_init(*this, fieldidx, minit_in, minit_out);
3354       }
3355     }
3356   }
3357 
3358   // Cast raw oop to the real thing...
3359   Node* javaoop = new CheckCastPPNode(control(), rawoop, oop_type);
3360   javaoop = _gvn.transform(javaoop);
3361   C->set_recent_alloc(control(), javaoop);
3362   assert(just_allocated_object(control()) == javaoop, "just allocated");
3363 
3364 #ifdef ASSERT
3365   { // Verify that the AllocateNode::Ideal_allocation recognizers work:
3366     assert(AllocateNode::Ideal_allocation(rawoop, &_gvn) == alloc,
3367            "Ideal_allocation works");
3368     assert(AllocateNode::Ideal_allocation(javaoop, &_gvn) == alloc,
3369            "Ideal_allocation works");
3370     if (alloc->is_AllocateArray()) {
3371       assert(AllocateArrayNode::Ideal_array_allocation(rawoop, &_gvn) == alloc->as_AllocateArray(),
3372              "Ideal_allocation works");
3373       assert(AllocateArrayNode::Ideal_array_allocation(javaoop, &_gvn) == alloc->as_AllocateArray(),
3374              "Ideal_allocation works");
3375     } else {
3376       assert(alloc->in(AllocateNode::ALength)->is_top(), "no length, please");
3377     }
3378   }
3379 #endif //ASSERT
3380 
3381   return javaoop;
3382 }
3383 
3384 //---------------------------new_instance--------------------------------------
3385 // This routine takes a klass_node which may be constant (for a static type)
3386 // or may be non-constant (for reflective code).  It will work equally well
3387 // for either, and the graph will fold nicely if the optimizer later reduces
3388 // the type to a constant.
3389 // The optional arguments are for specialized use by intrinsics:
3390 //  - If 'extra_slow_test' if not null is an extra condition for the slow-path.
3391 //  - If 'return_size_val', report the the total object size to the caller.
3392 //  - deoptimize_on_exception controls how Java exceptions are handled (rethrow vs deoptimize)
3393 Node* GraphKit::new_instance(Node* klass_node,
3394                              Node* extra_slow_test,
3395                              Node* *return_size_val,
3396                              bool deoptimize_on_exception) {
3397   // Compute size in doublewords
3398   // The size is always an integral number of doublewords, represented
3399   // as a positive bytewise size stored in the klass's layout_helper.
3400   // The layout_helper also encodes (in a low bit) the need for a slow path.
3401   jint  layout_con = Klass::_lh_neutral_value;
3402   Node* layout_val = get_layout_helper(klass_node, layout_con);
3403   int   layout_is_con = (layout_val == NULL);
3404 
3405   if (extra_slow_test == NULL)  extra_slow_test = intcon(0);
3406   // Generate the initial go-slow test.  It's either ALWAYS (return a
3407   // Node for 1) or NEVER (return a NULL) or perhaps (in the reflective
3408   // case) a computed value derived from the layout_helper.
3409   Node* initial_slow_test = NULL;
3410   if (layout_is_con) {
3411     assert(!StressReflectiveCode, "stress mode does not use these paths");
3412     bool must_go_slow = Klass::layout_helper_needs_slow_path(layout_con);
3413     initial_slow_test = must_go_slow? intcon(1): extra_slow_test;
3414 
3415   } else {   // reflective case
3416     // This reflective path is used by Unsafe.allocateInstance.
3417     // (It may be stress-tested by specifying StressReflectiveCode.)
3418     // Basically, we want to get into the VM is there's an illegal argument.
3419     Node* bit = intcon(Klass::_lh_instance_slow_path_bit);
3420     initial_slow_test = _gvn.transform( new AndINode(layout_val, bit) );
3421     if (extra_slow_test != intcon(0)) {
3422       initial_slow_test = _gvn.transform( new OrINode(initial_slow_test, extra_slow_test) );
3423     }
3424     // (Macro-expander will further convert this to a Bool, if necessary.)
3425   }
3426 
3427   // Find the size in bytes.  This is easy; it's the layout_helper.
3428   // The size value must be valid even if the slow path is taken.
3429   Node* size = NULL;
3430   if (layout_is_con) {
3431     size = MakeConX(Klass::layout_helper_size_in_bytes(layout_con));
3432   } else {   // reflective case
3433     // This reflective path is used by clone and Unsafe.allocateInstance.
3434     size = ConvI2X(layout_val);
3435 
3436     // Clear the low bits to extract layout_helper_size_in_bytes:
3437     assert((int)Klass::_lh_instance_slow_path_bit < BytesPerLong, "clear bit");
3438     Node* mask = MakeConX(~ (intptr_t)right_n_bits(LogBytesPerLong));
3439     size = _gvn.transform( new AndXNode(size, mask) );
3440   }
3441   if (return_size_val != NULL) {
3442     (*return_size_val) = size;
3443   }
3444 
3445   // This is a precise notnull oop of the klass.
3446   // (Actually, it need not be precise if this is a reflective allocation.)
3447   // It's what we cast the result to.
3448   const TypeKlassPtr* tklass = _gvn.type(klass_node)->isa_klassptr();
3449   if (!tklass)  tklass = TypeKlassPtr::OBJECT;
3450   const TypeOopPtr* oop_type = tklass->as_instance_type();
3451 
3452   // Now generate allocation code
3453 
3454   // The entire memory state is needed for slow path of the allocation
3455   // since GC and deoptimization can happened.
3456   Node *mem = reset_memory();
3457   set_all_memory(mem); // Create new memory state
3458 
3459   AllocateNode* alloc = new AllocateNode(C, AllocateNode::alloc_type(Type::TOP),
3460                                          control(), mem, i_o(),
3461                                          size, klass_node,
3462                                          initial_slow_test);
3463 
3464   return set_output_for_allocation(alloc, oop_type, deoptimize_on_exception);
3465 }
3466 
3467 //-------------------------------new_array-------------------------------------
3468 // helper for both newarray and anewarray
3469 // The 'length' parameter is (obviously) the length of the array.
3470 // See comments on new_instance for the meaning of the other arguments.
3471 Node* GraphKit::new_array(Node* klass_node,     // array klass (maybe variable)
3472                           Node* length,         // number of array elements
3473                           int   nargs,          // number of arguments to push back for uncommon trap
3474                           Node* *return_size_val,
3475                           bool deoptimize_on_exception) {
3476   jint  layout_con = Klass::_lh_neutral_value;
3477   Node* layout_val = get_layout_helper(klass_node, layout_con);
3478   int   layout_is_con = (layout_val == NULL);
3479 
3480   if (!layout_is_con && !StressReflectiveCode &&
3481       !too_many_traps(Deoptimization::Reason_class_check)) {
3482     // This is a reflective array creation site.
3483     // Optimistically assume that it is a subtype of Object[],
3484     // so that we can fold up all the address arithmetic.
3485     layout_con = Klass::array_layout_helper(T_OBJECT);
3486     Node* cmp_lh = _gvn.transform( new CmpINode(layout_val, intcon(layout_con)) );
3487     Node* bol_lh = _gvn.transform( new BoolNode(cmp_lh, BoolTest::eq) );
3488     { BuildCutout unless(this, bol_lh, PROB_MAX);
3489       inc_sp(nargs);
3490       uncommon_trap(Deoptimization::Reason_class_check,
3491                     Deoptimization::Action_maybe_recompile);
3492     }
3493     layout_val = NULL;
3494     layout_is_con = true;
3495   }
3496 
3497   // Generate the initial go-slow test.  Make sure we do not overflow
3498   // if length is huge (near 2Gig) or negative!  We do not need
3499   // exact double-words here, just a close approximation of needed
3500   // double-words.  We can't add any offset or rounding bits, lest we
3501   // take a size -1 of bytes and make it positive.  Use an unsigned
3502   // compare, so negative sizes look hugely positive.
3503   int fast_size_limit = FastAllocateSizeLimit;
3504   if (layout_is_con) {
3505     assert(!StressReflectiveCode, "stress mode does not use these paths");
3506     // Increase the size limit if we have exact knowledge of array type.
3507     int log2_esize = Klass::layout_helper_log2_element_size(layout_con);
3508     fast_size_limit <<= (LogBytesPerLong - log2_esize);
3509   }
3510 
3511   Node* initial_slow_cmp  = _gvn.transform( new CmpUNode( length, intcon( fast_size_limit ) ) );
3512   Node* initial_slow_test = _gvn.transform( new BoolNode( initial_slow_cmp, BoolTest::gt ) );
3513   if (initial_slow_test->is_Bool()) {
3514     // Hide it behind a CMoveI, or else PhaseIdealLoop::split_up will get sick.
3515     initial_slow_test = initial_slow_test->as_Bool()->as_int_value(&_gvn);
3516   }
3517 
3518   // --- Size Computation ---
3519   // array_size = round_to_heap(array_header + (length << elem_shift));
3520   // where round_to_heap(x) == round_to(x, MinObjAlignmentInBytes)
3521   // and round_to(x, y) == ((x + y-1) & ~(y-1))
3522   // The rounding mask is strength-reduced, if possible.
3523   int round_mask = MinObjAlignmentInBytes - 1;
3524   Node* header_size = NULL;
3525   int   header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
3526   // (T_BYTE has the weakest alignment and size restrictions...)
3527   if (layout_is_con) {
3528     int       hsize  = Klass::layout_helper_header_size(layout_con);
3529     int       eshift = Klass::layout_helper_log2_element_size(layout_con);
3530     BasicType etype  = Klass::layout_helper_element_type(layout_con);
3531     if ((round_mask & ~right_n_bits(eshift)) == 0)
3532       round_mask = 0;  // strength-reduce it if it goes away completely
3533     assert((hsize & right_n_bits(eshift)) == 0, "hsize is pre-rounded");
3534     assert(header_size_min <= hsize, "generic minimum is smallest");
3535     header_size_min = hsize;
3536     header_size = intcon(hsize + round_mask);
3537   } else {
3538     Node* hss   = intcon(Klass::_lh_header_size_shift);
3539     Node* hsm   = intcon(Klass::_lh_header_size_mask);
3540     Node* hsize = _gvn.transform( new URShiftINode(layout_val, hss) );
3541     hsize       = _gvn.transform( new AndINode(hsize, hsm) );
3542     Node* mask  = intcon(round_mask);
3543     header_size = _gvn.transform( new AddINode(hsize, mask) );
3544   }
3545 
3546   Node* elem_shift = NULL;
3547   if (layout_is_con) {
3548     int eshift = Klass::layout_helper_log2_element_size(layout_con);
3549     if (eshift != 0)
3550       elem_shift = intcon(eshift);
3551   } else {
3552     // There is no need to mask or shift this value.
3553     // The semantics of LShiftINode include an implicit mask to 0x1F.
3554     assert(Klass::_lh_log2_element_size_shift == 0, "use shift in place");
3555     elem_shift = layout_val;
3556   }
3557 
3558   // Transition to native address size for all offset calculations:
3559   Node* lengthx = ConvI2X(length);
3560   Node* headerx = ConvI2X(header_size);
3561 #ifdef _LP64
3562   { const TypeLong* tllen = _gvn.find_long_type(lengthx);
3563     if (tllen != NULL && tllen->_lo < 0) {
3564       // Add a manual constraint to a positive range.  Cf. array_element_address.
3565       jlong size_max = arrayOopDesc::max_array_length(T_BYTE);
3566       if (size_max > tllen->_hi)  size_max = tllen->_hi;
3567       const TypeLong* tlcon = TypeLong::make(CONST64(0), size_max, Type::WidenMin);
3568       lengthx = _gvn.transform( new ConvI2LNode(length, tlcon));
3569     }
3570   }
3571 #endif
3572 
3573   // Combine header size (plus rounding) and body size.  Then round down.
3574   // This computation cannot overflow, because it is used only in two
3575   // places, one where the length is sharply limited, and the other
3576   // after a successful allocation.
3577   Node* abody = lengthx;
3578   if (elem_shift != NULL)
3579     abody     = _gvn.transform( new LShiftXNode(lengthx, elem_shift) );
3580   Node* size  = _gvn.transform( new AddXNode(headerx, abody) );
3581   if (round_mask != 0) {
3582     Node* mask = MakeConX(~round_mask);
3583     size       = _gvn.transform( new AndXNode(size, mask) );
3584   }
3585   // else if round_mask == 0, the size computation is self-rounding
3586 
3587   if (return_size_val != NULL) {
3588     // This is the size
3589     (*return_size_val) = size;
3590   }
3591 
3592   // Now generate allocation code
3593 
3594   // The entire memory state is needed for slow path of the allocation
3595   // since GC and deoptimization can happened.
3596   Node *mem = reset_memory();
3597   set_all_memory(mem); // Create new memory state
3598 
3599   // Create the AllocateArrayNode and its result projections
3600   AllocateArrayNode* alloc
3601     = new AllocateArrayNode(C, AllocateArrayNode::alloc_type(TypeInt::INT),
3602                             control(), mem, i_o(),
3603                             size, klass_node,
3604                             initial_slow_test,
3605                             length);
3606 
3607   // Cast to correct type.  Note that the klass_node may be constant or not,
3608   // and in the latter case the actual array type will be inexact also.
3609   // (This happens via a non-constant argument to inline_native_newArray.)
3610   // In any case, the value of klass_node provides the desired array type.
3611   const TypeInt* length_type = _gvn.find_int_type(length);
3612   const TypeOopPtr* ary_type = _gvn.type(klass_node)->is_klassptr()->as_instance_type();
3613   if (ary_type->isa_aryptr() && length_type != NULL) {
3614     // Try to get a better type than POS for the size
3615     ary_type = ary_type->is_aryptr()->cast_to_size(length_type);
3616   }
3617 
3618   Node* javaoop = set_output_for_allocation(alloc, ary_type, deoptimize_on_exception);
3619 
3620   // Cast length on remaining path to be as narrow as possible
3621   if (map()->find_edge(length) >= 0) {
3622     Node* ccast = alloc->make_ideal_length(ary_type, &_gvn);
3623     if (ccast != length) {
3624       _gvn.set_type_bottom(ccast);
3625       record_for_igvn(ccast);
3626       replace_in_map(length, ccast);
3627     }
3628   }
3629 
3630   return javaoop;
3631 }
3632 
3633 // The following "Ideal_foo" functions are placed here because they recognize
3634 // the graph shapes created by the functions immediately above.
3635 
3636 //---------------------------Ideal_allocation----------------------------------
3637 // Given an oop pointer or raw pointer, see if it feeds from an AllocateNode.
3638 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase) {
3639   if (ptr == NULL) {     // reduce dumb test in callers
3640     return NULL;
3641   }
3642   if (ptr->is_CheckCastPP()) { // strip only one raw-to-oop cast
3643     ptr = ptr->in(1);
3644     if (ptr == NULL) return NULL;
3645   }
3646   // Return NULL for allocations with several casts:
3647   //   j.l.reflect.Array.newInstance(jobject, jint)
3648   //   Object.clone()
3649   // to keep more precise type from last cast.
3650   if (ptr->is_Proj()) {
3651     Node* allo = ptr->in(0);
3652     if (allo != NULL && allo->is_Allocate()) {
3653       return allo->as_Allocate();
3654     }
3655   }
3656   // Report failure to match.
3657   return NULL;
3658 }
3659 
3660 // Fancy version which also strips off an offset (and reports it to caller).
3661 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase,
3662                                              intptr_t& offset) {
3663   Node* base = AddPNode::Ideal_base_and_offset(ptr, phase, offset);
3664   if (base == NULL)  return NULL;
3665   return Ideal_allocation(base, phase);
3666 }
3667 
3668 // Trace Initialize <- Proj[Parm] <- Allocate
3669 AllocateNode* InitializeNode::allocation() {
3670   Node* rawoop = in(InitializeNode::RawAddress);
3671   if (rawoop->is_Proj()) {
3672     Node* alloc = rawoop->in(0);
3673     if (alloc->is_Allocate()) {
3674       return alloc->as_Allocate();
3675     }
3676   }
3677   return NULL;
3678 }
3679 
3680 // Trace Allocate -> Proj[Parm] -> Initialize
3681 InitializeNode* AllocateNode::initialization() {
3682   ProjNode* rawoop = proj_out(AllocateNode::RawAddress);
3683   if (rawoop == NULL)  return NULL;
3684   for (DUIterator_Fast imax, i = rawoop->fast_outs(imax); i < imax; i++) {
3685     Node* init = rawoop->fast_out(i);
3686     if (init->is_Initialize()) {
3687       assert(init->as_Initialize()->allocation() == this, "2-way link");
3688       return init->as_Initialize();
3689     }
3690   }
3691   return NULL;
3692 }
3693 
3694 //----------------------------- loop predicates ---------------------------
3695 
3696 //------------------------------add_predicate_impl----------------------------
3697 void GraphKit::add_predicate_impl(Deoptimization::DeoptReason reason, int nargs) {
3698   // Too many traps seen?
3699   if (too_many_traps(reason)) {
3700 #ifdef ASSERT
3701     if (TraceLoopPredicate) {
3702       int tc = C->trap_count(reason);
3703       tty->print("too many traps=%s tcount=%d in ",
3704                     Deoptimization::trap_reason_name(reason), tc);
3705       method()->print(); // which method has too many predicate traps
3706       tty->cr();
3707     }
3708 #endif
3709     // We cannot afford to take more traps here,
3710     // do not generate predicate.
3711     return;
3712   }
3713 
3714   Node *cont    = _gvn.intcon(1);
3715   Node* opq     = _gvn.transform(new Opaque1Node(C, cont));
3716   Node *bol     = _gvn.transform(new Conv2BNode(opq));
3717   IfNode* iff   = create_and_map_if(control(), bol, PROB_MAX, COUNT_UNKNOWN);
3718   Node* iffalse = _gvn.transform(new IfFalseNode(iff));
3719   C->add_predicate_opaq(opq);
3720   {
3721     PreserveJVMState pjvms(this);
3722     set_control(iffalse);
3723     inc_sp(nargs);
3724     uncommon_trap(reason, Deoptimization::Action_maybe_recompile);
3725   }
3726   Node* iftrue = _gvn.transform(new IfTrueNode(iff));
3727   set_control(iftrue);
3728 }
3729 
3730 //------------------------------add_predicate---------------------------------
3731 void GraphKit::add_predicate(int nargs) {
3732   if (UseLoopPredicate) {
3733     add_predicate_impl(Deoptimization::Reason_predicate, nargs);
3734   }
3735   // loop's limit check predicate should be near the loop.
3736   if (LoopLimitCheck) {
3737     add_predicate_impl(Deoptimization::Reason_loop_limit_check, nargs);
3738   }
3739 }
3740 
3741 //----------------------------- store barriers ----------------------------
3742 #define __ ideal.
3743 
3744 void GraphKit::sync_kit(IdealKit& ideal) {
3745   set_all_memory(__ merged_memory());
3746   set_i_o(__ i_o());
3747   set_control(__ ctrl());
3748 }
3749 
3750 void GraphKit::final_sync(IdealKit& ideal) {
3751   // Final sync IdealKit and graphKit.
3752   sync_kit(ideal);
3753 }
3754 
3755 // vanilla/CMS post barrier
3756 // Insert a write-barrier store.  This is to let generational GC work; we have
3757 // to flag all oop-stores before the next GC point.
3758 void GraphKit::write_barrier_post(Node* oop_store,
3759                                   Node* obj,
3760                                   Node* adr,
3761                                   uint  adr_idx,
3762                                   Node* val,
3763                                   bool use_precise) {
3764   // No store check needed if we're storing a NULL or an old object
3765   // (latter case is probably a string constant). The concurrent
3766   // mark sweep garbage collector, however, needs to have all nonNull
3767   // oop updates flagged via card-marks.
3768   if (val != NULL && val->is_Con()) {
3769     // must be either an oop or NULL
3770     const Type* t = val->bottom_type();
3771     if (t == TypePtr::NULL_PTR || t == Type::TOP)
3772       // stores of null never (?) need barriers
3773       return;
3774   }
3775 
3776   if (use_ReduceInitialCardMarks()
3777       && obj == just_allocated_object(control())) {
3778     // We can skip marks on a freshly-allocated object in Eden.
3779     // Keep this code in sync with new_store_pre_barrier() in runtime.cpp.
3780     // That routine informs GC to take appropriate compensating steps,
3781     // upon a slow-path allocation, so as to make this card-mark
3782     // elision safe.
3783     return;
3784   }
3785 
3786   if (!use_precise) {
3787     // All card marks for a (non-array) instance are in one place:
3788     adr = obj;
3789   }
3790   // (Else it's an array (or unknown), and we want more precise card marks.)
3791   assert(adr != NULL, "");
3792 
3793   IdealKit ideal(this, true);
3794 
3795   // Convert the pointer to an int prior to doing math on it
3796   Node* cast = __ CastPX(__ ctrl(), adr);
3797 
3798   // Divide by card size
3799   assert(Universe::heap()->barrier_set()->kind() == BarrierSet::CardTableModRef,
3800          "Only one we handle so far.");
3801   Node* card_offset = __ URShiftX( cast, __ ConI(CardTableModRefBS::card_shift) );
3802 
3803   // Combine card table base and card offset
3804   Node* card_adr = __ AddP(__ top(), byte_map_base_node(), card_offset );
3805 
3806   // Get the alias_index for raw card-mark memory
3807   int adr_type = Compile::AliasIdxRaw;
3808   Node*   zero = __ ConI(0); // Dirty card value
3809   BasicType bt = T_BYTE;
3810 
3811   if (UseCondCardMark) {
3812     // The classic GC reference write barrier is typically implemented
3813     // as a store into the global card mark table.  Unfortunately
3814     // unconditional stores can result in false sharing and excessive
3815     // coherence traffic as well as false transactional aborts.
3816     // UseCondCardMark enables MP "polite" conditional card mark
3817     // stores.  In theory we could relax the load from ctrl() to
3818     // no_ctrl, but that doesn't buy much latitude.
3819     Node* card_val = __ load( __ ctrl(), card_adr, TypeInt::BYTE, bt, adr_type);
3820     __ if_then(card_val, BoolTest::ne, zero);
3821   }
3822 
3823   // Smash zero into card
3824   if( !UseConcMarkSweepGC ) {
3825     __ store(__ ctrl(), card_adr, zero, bt, adr_type, MemNode::release);
3826   } else {
3827     // Specialized path for CM store barrier
3828     __ storeCM(__ ctrl(), card_adr, zero, oop_store, adr_idx, bt, adr_type);
3829   }
3830 
3831   if (UseCondCardMark) {
3832     __ end_if();
3833   }
3834 
3835   // Final sync IdealKit and GraphKit.
3836   final_sync(ideal);
3837 }
3838 /*
3839  * Determine if the G1 pre-barrier can be removed. The pre-barrier is
3840  * required by SATB to make sure all objects live at the start of the
3841  * marking are kept alive, all reference updates need to any previous
3842  * reference stored before writing.
3843  *
3844  * If the previous value is NULL there is no need to save the old value.
3845  * References that are NULL are filtered during runtime by the barrier
3846  * code to avoid unnecessary queuing.
3847  *
3848  * However in the case of newly allocated objects it might be possible to
3849  * prove that the reference about to be overwritten is NULL during compile
3850  * time and avoid adding the barrier code completely.
3851  *
3852  * The compiler needs to determine that the object in which a field is about
3853  * to be written is newly allocated, and that no prior store to the same field
3854  * has happened since the allocation.
3855  *
3856  * Returns true if the pre-barrier can be removed
3857  */
3858 bool GraphKit::g1_can_remove_pre_barrier(PhaseTransform* phase, Node* adr,
3859                                          BasicType bt, uint adr_idx) {
3860   intptr_t offset = 0;
3861   Node* base = AddPNode::Ideal_base_and_offset(adr, phase, offset);
3862   AllocateNode* alloc = AllocateNode::Ideal_allocation(base, phase);
3863 
3864   if (offset == Type::OffsetBot) {
3865     return false; // cannot unalias unless there are precise offsets
3866   }
3867 
3868   if (alloc == NULL) {
3869     return false; // No allocation found
3870   }
3871 
3872   intptr_t size_in_bytes = type2aelembytes(bt);
3873 
3874   Node* mem = memory(adr_idx); // start searching here...
3875 
3876   for (int cnt = 0; cnt < 50; cnt++) {
3877 
3878     if (mem->is_Store()) {
3879 
3880       Node* st_adr = mem->in(MemNode::Address);
3881       intptr_t st_offset = 0;
3882       Node* st_base = AddPNode::Ideal_base_and_offset(st_adr, phase, st_offset);
3883 
3884       if (st_base == NULL) {
3885         break; // inscrutable pointer
3886       }
3887 
3888       // Break we have found a store with same base and offset as ours so break
3889       if (st_base == base && st_offset == offset) {
3890         break;
3891       }
3892 
3893       if (st_offset != offset && st_offset != Type::OffsetBot) {
3894         const int MAX_STORE = BytesPerLong;
3895         if (st_offset >= offset + size_in_bytes ||
3896             st_offset <= offset - MAX_STORE ||
3897             st_offset <= offset - mem->as_Store()->memory_size()) {
3898           // Success:  The offsets are provably independent.
3899           // (You may ask, why not just test st_offset != offset and be done?
3900           // The answer is that stores of different sizes can co-exist
3901           // in the same sequence of RawMem effects.  We sometimes initialize
3902           // a whole 'tile' of array elements with a single jint or jlong.)
3903           mem = mem->in(MemNode::Memory);
3904           continue; // advance through independent store memory
3905         }
3906       }
3907 
3908       if (st_base != base
3909           && MemNode::detect_ptr_independence(base, alloc, st_base,
3910                                               AllocateNode::Ideal_allocation(st_base, phase),
3911                                               phase)) {
3912         // Success:  The bases are provably independent.
3913         mem = mem->in(MemNode::Memory);
3914         continue; // advance through independent store memory
3915       }
3916     } else if (mem->is_Proj() && mem->in(0)->is_Initialize()) {
3917 
3918       InitializeNode* st_init = mem->in(0)->as_Initialize();
3919       AllocateNode* st_alloc = st_init->allocation();
3920 
3921       // Make sure that we are looking at the same allocation site.
3922       // The alloc variable is guaranteed to not be null here from earlier check.
3923       if (alloc == st_alloc) {
3924         // Check that the initialization is storing NULL so that no previous store
3925         // has been moved up and directly write a reference
3926         Node* captured_store = st_init->find_captured_store(offset,
3927                                                             type2aelembytes(T_OBJECT),
3928                                                             phase);
3929         if (captured_store == NULL || captured_store == st_init->zero_memory()) {
3930           return true;
3931         }
3932       }
3933     }
3934 
3935     // Unless there is an explicit 'continue', we must bail out here,
3936     // because 'mem' is an inscrutable memory state (e.g., a call).
3937     break;
3938   }
3939 
3940   return false;
3941 }
3942 
3943 // G1 pre/post barriers
3944 void GraphKit::g1_write_barrier_pre(bool do_load,
3945                                     Node* obj,
3946                                     Node* adr,
3947                                     uint alias_idx,
3948                                     Node* val,
3949                                     const TypeOopPtr* val_type,
3950                                     Node* pre_val,
3951                                     BasicType bt) {
3952 
3953   // Some sanity checks
3954   // Note: val is unused in this routine.
3955 
3956   if (do_load) {
3957     // We need to generate the load of the previous value
3958     assert(obj != NULL, "must have a base");
3959     assert(adr != NULL, "where are loading from?");
3960     assert(pre_val == NULL, "loaded already?");
3961     assert(val_type != NULL, "need a type");
3962 
3963     if (use_ReduceInitialCardMarks()
3964         && g1_can_remove_pre_barrier(&_gvn, adr, bt, alias_idx)) {
3965       return;
3966     }
3967 
3968   } else {
3969     // In this case both val_type and alias_idx are unused.
3970     assert(pre_val != NULL, "must be loaded already");
3971     // Nothing to be done if pre_val is null.
3972     if (pre_val->bottom_type() == TypePtr::NULL_PTR) return;
3973     assert(pre_val->bottom_type()->basic_type() == T_OBJECT, "or we shouldn't be here");
3974   }
3975   assert(bt == T_OBJECT, "or we shouldn't be here");
3976 
3977   IdealKit ideal(this, true);
3978 
3979   Node* tls = __ thread(); // ThreadLocalStorage
3980 
3981   Node* no_ctrl = NULL;
3982   Node* no_base = __ top();
3983   Node* zero  = __ ConI(0);
3984   Node* zeroX = __ ConX(0);
3985 
3986   float likely  = PROB_LIKELY(0.999);
3987   float unlikely  = PROB_UNLIKELY(0.999);
3988 
3989   BasicType active_type = in_bytes(PtrQueue::byte_width_of_active()) == 4 ? T_INT : T_BYTE;
3990   assert(in_bytes(PtrQueue::byte_width_of_active()) == 4 || in_bytes(PtrQueue::byte_width_of_active()) == 1, "flag width");
3991 
3992   // Offsets into the thread
3993   const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() +  // 648
3994                                           PtrQueue::byte_offset_of_active());
3995   const int index_offset   = in_bytes(JavaThread::satb_mark_queue_offset() +  // 656
3996                                           PtrQueue::byte_offset_of_index());
3997   const int buffer_offset  = in_bytes(JavaThread::satb_mark_queue_offset() +  // 652
3998                                           PtrQueue::byte_offset_of_buf());
3999 
4000   // Now the actual pointers into the thread
4001   Node* marking_adr = __ AddP(no_base, tls, __ ConX(marking_offset));
4002   Node* buffer_adr  = __ AddP(no_base, tls, __ ConX(buffer_offset));
4003   Node* index_adr   = __ AddP(no_base, tls, __ ConX(index_offset));
4004 
4005   // Now some of the values
4006   Node* marking = __ load(__ ctrl(), marking_adr, TypeInt::INT, active_type, Compile::AliasIdxRaw);
4007 
4008   // if (!marking)
4009   __ if_then(marking, BoolTest::ne, zero, unlikely); {
4010     BasicType index_bt = TypeX_X->basic_type();
4011     assert(sizeof(size_t) == type2aelembytes(index_bt), "Loading G1 PtrQueue::_index with wrong size.");
4012     Node* index   = __ load(__ ctrl(), index_adr, TypeX_X, index_bt, Compile::AliasIdxRaw);
4013 
4014     if (do_load) {
4015       // load original value
4016       // alias_idx correct??
4017       pre_val = __ load(__ ctrl(), adr, val_type, bt, alias_idx);
4018     }
4019 
4020     // if (pre_val != NULL)
4021     __ if_then(pre_val, BoolTest::ne, null()); {
4022       Node* buffer  = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
4023 
4024       // is the queue for this thread full?
4025       __ if_then(index, BoolTest::ne, zeroX, likely); {
4026 
4027         // decrement the index
4028         Node* next_index = _gvn.transform(new SubXNode(index, __ ConX(sizeof(intptr_t))));
4029 
4030         // Now get the buffer location we will log the previous value into and store it
4031         Node *log_addr = __ AddP(no_base, buffer, next_index);
4032         __ store(__ ctrl(), log_addr, pre_val, T_OBJECT, Compile::AliasIdxRaw, MemNode::unordered);
4033         // update the index
4034         __ store(__ ctrl(), index_adr, next_index, index_bt, Compile::AliasIdxRaw, MemNode::unordered);
4035 
4036       } __ else_(); {
4037 
4038         // logging buffer is full, call the runtime
4039         const TypeFunc *tf = OptoRuntime::g1_wb_pre_Type();
4040         __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_pre), "g1_wb_pre", pre_val, tls);
4041       } __ end_if();  // (!index)
4042     } __ end_if();  // (pre_val != NULL)
4043   } __ end_if();  // (!marking)
4044 
4045   // Final sync IdealKit and GraphKit.
4046   final_sync(ideal);
4047 }
4048 
4049 /*
4050  * G1 similar to any GC with a Young Generation requires a way to keep track of
4051  * references from Old Generation to Young Generation to make sure all live
4052  * objects are found. G1 also requires to keep track of object references
4053  * between different regions to enable evacuation of old regions, which is done
4054  * as part of mixed collections. References are tracked in remembered sets and
4055  * is continuously updated as reference are written to with the help of the
4056  * post-barrier.
4057  *
4058  * To reduce the number of updates to the remembered set the post-barrier
4059  * filters updates to fields in objects located in the Young Generation,
4060  * the same region as the reference, when the NULL is being written or
4061  * if the card is already marked as dirty by an earlier write.
4062  *
4063  * Under certain circumstances it is possible to avoid generating the
4064  * post-barrier completely if it is possible during compile time to prove
4065  * the object is newly allocated and that no safepoint exists between the
4066  * allocation and the store.
4067  *
4068  * In the case of slow allocation the allocation code must handle the barrier
4069  * as part of the allocation in the case the allocated object is not located
4070  * in the nursery, this would happen for humongous objects. This is similar to
4071  * how CMS is required to handle this case, see the comments for the method
4072  * CollectedHeap::new_store_pre_barrier and OptoRuntime::new_store_pre_barrier.
4073  * A deferred card mark is required for these objects and handled in the above
4074  * mentioned methods.
4075  *
4076  * Returns true if the post barrier can be removed
4077  */
4078 bool GraphKit::g1_can_remove_post_barrier(PhaseTransform* phase, Node* store,
4079                                           Node* adr) {
4080   intptr_t      offset = 0;
4081   Node*         base   = AddPNode::Ideal_base_and_offset(adr, phase, offset);
4082   AllocateNode* alloc  = AllocateNode::Ideal_allocation(base, phase);
4083 
4084   if (offset == Type::OffsetBot) {
4085     return false; // cannot unalias unless there are precise offsets
4086   }
4087 
4088   if (alloc == NULL) {
4089      return false; // No allocation found
4090   }
4091 
4092   // Start search from Store node
4093   Node* mem = store->in(MemNode::Control);
4094   if (mem->is_Proj() && mem->in(0)->is_Initialize()) {
4095 
4096     InitializeNode* st_init = mem->in(0)->as_Initialize();
4097     AllocateNode*  st_alloc = st_init->allocation();
4098 
4099     // Make sure we are looking at the same allocation
4100     if (alloc == st_alloc) {
4101       return true;
4102     }
4103   }
4104 
4105   return false;
4106 }
4107 
4108 //
4109 // Update the card table and add card address to the queue
4110 //
4111 void GraphKit::g1_mark_card(IdealKit& ideal,
4112                             Node* card_adr,
4113                             Node* oop_store,
4114                             uint oop_alias_idx,
4115                             Node* index,
4116                             Node* index_adr,
4117                             Node* buffer,
4118                             const TypeFunc* tf) {
4119 
4120   Node* zero  = __ ConI(0);
4121   Node* zeroX = __ ConX(0);
4122   Node* no_base = __ top();
4123   BasicType card_bt = T_BYTE;
4124   // Smash zero into card. MUST BE ORDERED WRT TO STORE
4125   __ storeCM(__ ctrl(), card_adr, zero, oop_store, oop_alias_idx, card_bt, Compile::AliasIdxRaw);
4126 
4127   //  Now do the queue work
4128   __ if_then(index, BoolTest::ne, zeroX); {
4129 
4130     Node* next_index = _gvn.transform(new SubXNode(index, __ ConX(sizeof(intptr_t))));
4131     Node* log_addr = __ AddP(no_base, buffer, next_index);
4132 
4133     // Order, see storeCM.
4134     __ store(__ ctrl(), log_addr, card_adr, T_ADDRESS, Compile::AliasIdxRaw, MemNode::unordered);
4135     __ store(__ ctrl(), index_adr, next_index, TypeX_X->basic_type(), Compile::AliasIdxRaw, MemNode::unordered);
4136 
4137   } __ else_(); {
4138     __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_post), "g1_wb_post", card_adr, __ thread());
4139   } __ end_if();
4140 
4141 }
4142 
4143 void GraphKit::g1_write_barrier_post(Node* oop_store,
4144                                      Node* obj,
4145                                      Node* adr,
4146                                      uint alias_idx,
4147                                      Node* val,
4148                                      BasicType bt,
4149                                      bool use_precise) {
4150   // If we are writing a NULL then we need no post barrier
4151 
4152   if (val != NULL && val->is_Con() && val->bottom_type() == TypePtr::NULL_PTR) {
4153     // Must be NULL
4154     const Type* t = val->bottom_type();
4155     assert(t == Type::TOP || t == TypePtr::NULL_PTR, "must be NULL");
4156     // No post barrier if writing NULLx
4157     return;
4158   }
4159 
4160   if (use_ReduceInitialCardMarks() && obj == just_allocated_object(control())) {
4161     // We can skip marks on a freshly-allocated object in Eden.
4162     // Keep this code in sync with new_store_pre_barrier() in runtime.cpp.
4163     // That routine informs GC to take appropriate compensating steps,
4164     // upon a slow-path allocation, so as to make this card-mark
4165     // elision safe.
4166     return;
4167   }
4168 
4169   if (use_ReduceInitialCardMarks()
4170       && g1_can_remove_post_barrier(&_gvn, oop_store, adr)) {
4171     return;
4172   }
4173 
4174   if (!use_precise) {
4175     // All card marks for a (non-array) instance are in one place:
4176     adr = obj;
4177   }
4178   // (Else it's an array (or unknown), and we want more precise card marks.)
4179   assert(adr != NULL, "");
4180 
4181   IdealKit ideal(this, true);
4182 
4183   Node* tls = __ thread(); // ThreadLocalStorage
4184 
4185   Node* no_base = __ top();
4186   float likely  = PROB_LIKELY(0.999);
4187   float unlikely  = PROB_UNLIKELY(0.999);
4188   Node* young_card = __ ConI((jint)G1SATBCardTableModRefBS::g1_young_card_val());
4189   Node* dirty_card = __ ConI((jint)CardTableModRefBS::dirty_card_val());
4190   Node* zeroX = __ ConX(0);
4191 
4192   // Get the alias_index for raw card-mark memory
4193   const TypePtr* card_type = TypeRawPtr::BOTTOM;
4194 
4195   const TypeFunc *tf = OptoRuntime::g1_wb_post_Type();
4196 
4197   // Offsets into the thread
4198   const int index_offset  = in_bytes(JavaThread::dirty_card_queue_offset() +
4199                                      PtrQueue::byte_offset_of_index());
4200   const int buffer_offset = in_bytes(JavaThread::dirty_card_queue_offset() +
4201                                      PtrQueue::byte_offset_of_buf());
4202 
4203   // Pointers into the thread
4204 
4205   Node* buffer_adr = __ AddP(no_base, tls, __ ConX(buffer_offset));
4206   Node* index_adr =  __ AddP(no_base, tls, __ ConX(index_offset));
4207 
4208   // Now some values
4209   // Use ctrl to avoid hoisting these values past a safepoint, which could
4210   // potentially reset these fields in the JavaThread.
4211   Node* index  = __ load(__ ctrl(), index_adr, TypeX_X, TypeX_X->basic_type(), Compile::AliasIdxRaw);
4212   Node* buffer = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
4213 
4214   // Convert the store obj pointer to an int prior to doing math on it
4215   // Must use ctrl to prevent "integerized oop" existing across safepoint
4216   Node* cast =  __ CastPX(__ ctrl(), adr);
4217 
4218   // Divide pointer by card size
4219   Node* card_offset = __ URShiftX( cast, __ ConI(CardTableModRefBS::card_shift) );
4220 
4221   // Combine card table base and card offset
4222   Node* card_adr = __ AddP(no_base, byte_map_base_node(), card_offset );
4223 
4224   // If we know the value being stored does it cross regions?
4225 
4226   if (val != NULL) {
4227     // Does the store cause us to cross regions?
4228 
4229     // Should be able to do an unsigned compare of region_size instead of
4230     // and extra shift. Do we have an unsigned compare??
4231     // Node* region_size = __ ConI(1 << HeapRegion::LogOfHRGrainBytes);
4232     Node* xor_res =  __ URShiftX ( __ XorX( cast,  __ CastPX(__ ctrl(), val)), __ ConI(HeapRegion::LogOfHRGrainBytes));
4233 
4234     // if (xor_res == 0) same region so skip
4235     __ if_then(xor_res, BoolTest::ne, zeroX); {
4236 
4237       // No barrier if we are storing a NULL
4238       __ if_then(val, BoolTest::ne, null(), unlikely); {
4239 
4240         // Ok must mark the card if not already dirty
4241 
4242         // load the original value of the card
4243         Node* card_val = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
4244 
4245         __ if_then(card_val, BoolTest::ne, young_card); {
4246           sync_kit(ideal);
4247           // Use Op_MemBarVolatile to achieve the effect of a StoreLoad barrier.
4248           insert_mem_bar(Op_MemBarVolatile, oop_store);
4249           __ sync_kit(this);
4250 
4251           Node* card_val_reload = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
4252           __ if_then(card_val_reload, BoolTest::ne, dirty_card); {
4253             g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
4254           } __ end_if();
4255         } __ end_if();
4256       } __ end_if();
4257     } __ end_if();
4258   } else {
4259     // Object.clone() instrinsic uses this path.
4260     g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
4261   }
4262 
4263   // Final sync IdealKit and GraphKit.
4264   final_sync(ideal);
4265 }
4266 #undef __
4267 
4268 
4269 
4270 Node* GraphKit::load_String_offset(Node* ctrl, Node* str) {
4271   if (java_lang_String::has_offset_field()) {
4272     int offset_offset = java_lang_String::offset_offset_in_bytes();
4273     const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4274                                                        false, NULL, 0);
4275     const TypePtr* offset_field_type = string_type->add_offset(offset_offset);
4276     int offset_field_idx = C->get_alias_index(offset_field_type);
4277     return make_load(ctrl,
4278                      basic_plus_adr(str, str, offset_offset),
4279                      TypeInt::INT, T_INT, offset_field_idx, MemNode::unordered);
4280   } else {
4281     return intcon(0);
4282   }
4283 }
4284 
4285 Node* GraphKit::load_String_length(Node* ctrl, Node* str) {
4286   if (java_lang_String::has_count_field()) {
4287     int count_offset = java_lang_String::count_offset_in_bytes();
4288     const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4289                                                        false, NULL, 0);
4290     const TypePtr* count_field_type = string_type->add_offset(count_offset);
4291     int count_field_idx = C->get_alias_index(count_field_type);
4292     return make_load(ctrl,
4293                      basic_plus_adr(str, str, count_offset),
4294                      TypeInt::INT, T_INT, count_field_idx, MemNode::unordered);
4295   } else {
4296     return load_array_length(load_String_value(ctrl, str));
4297   }
4298 }
4299 
4300 Node* GraphKit::load_String_value(Node* ctrl, Node* str) {
4301   int value_offset = java_lang_String::value_offset_in_bytes();
4302   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4303                                                      false, NULL, 0);
4304   const TypePtr* value_field_type = string_type->add_offset(value_offset);
4305   const TypeAryPtr*  value_type = TypeAryPtr::make(TypePtr::NotNull,
4306                                                    TypeAry::make(TypeInt::CHAR,TypeInt::POS),
4307                                                    ciTypeArrayKlass::make(T_CHAR), true, 0);
4308   int value_field_idx = C->get_alias_index(value_field_type);
4309   Node* load = make_load(ctrl, basic_plus_adr(str, str, value_offset),
4310                          value_type, T_OBJECT, value_field_idx, MemNode::unordered);
4311   // String.value field is known to be @Stable.
4312   if (UseImplicitStableValues) {
4313     load = cast_array_to_stable(load, value_type);
4314   }
4315   return load;
4316 }
4317 
4318 void GraphKit::store_String_offset(Node* ctrl, Node* str, Node* value) {
4319   int offset_offset = java_lang_String::offset_offset_in_bytes();
4320   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4321                                                      false, NULL, 0);
4322   const TypePtr* offset_field_type = string_type->add_offset(offset_offset);
4323   int offset_field_idx = C->get_alias_index(offset_field_type);
4324   store_to_memory(ctrl, basic_plus_adr(str, offset_offset),
4325                   value, T_INT, offset_field_idx, MemNode::unordered);
4326 }
4327 
4328 void GraphKit::store_String_value(Node* ctrl, Node* str, Node* value) {
4329   int value_offset = java_lang_String::value_offset_in_bytes();
4330   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4331                                                      false, NULL, 0);
4332   const TypePtr* value_field_type = string_type->add_offset(value_offset);
4333 
4334   store_oop_to_object(ctrl, str,  basic_plus_adr(str, value_offset), value_field_type,
4335       value, TypeAryPtr::CHARS, T_OBJECT, MemNode::unordered);
4336 }
4337 
4338 void GraphKit::store_String_length(Node* ctrl, Node* str, Node* value) {
4339   int count_offset = java_lang_String::count_offset_in_bytes();
4340   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4341                                                      false, NULL, 0);
4342   const TypePtr* count_field_type = string_type->add_offset(count_offset);
4343   int count_field_idx = C->get_alias_index(count_field_type);
4344   store_to_memory(ctrl, basic_plus_adr(str, count_offset),
4345                   value, T_INT, count_field_idx, MemNode::unordered);
4346 }
4347 
4348 Node* GraphKit::cast_array_to_stable(Node* ary, const TypeAryPtr* ary_type) {
4349   // Reify the property as a CastPP node in Ideal graph to comply with monotonicity
4350   // assumption of CCP analysis.
4351   return _gvn.transform(new CastPPNode(ary, ary_type->cast_to_stable(true)));
4352 }