1 /*
   2  * Copyright (c) 2001, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "compiler/compileLog.hpp"
  27 #include "ci/ciValueKlass.hpp"
  28 #include "gc/g1/g1SATBCardTableModRefBS.hpp"
  29 #include "gc/g1/heapRegion.hpp"
  30 #include "gc/shared/barrierSet.hpp"
  31 #include "gc/shared/cardTableModRefBS.hpp"
  32 #include "gc/shared/collectedHeap.hpp"
  33 #include "memory/resourceArea.hpp"
  34 #include "opto/addnode.hpp"
  35 #include "opto/castnode.hpp"
  36 #include "opto/convertnode.hpp"
  37 #include "opto/graphKit.hpp"
  38 #include "opto/idealKit.hpp"
  39 #include "opto/intrinsicnode.hpp"
  40 #include "opto/locknode.hpp"
  41 #include "opto/machnode.hpp"
  42 #include "opto/opaquenode.hpp"
  43 #include "opto/parse.hpp"
  44 #include "opto/rootnode.hpp"
  45 #include "opto/runtime.hpp"
  46 #include "opto/valuetypenode.hpp"
  47 #include "runtime/deoptimization.hpp"
  48 #include "runtime/sharedRuntime.hpp"
  49 
  50 //----------------------------GraphKit-----------------------------------------
  51 // Main utility constructor.
  52 GraphKit::GraphKit(JVMState* jvms, PhaseGVN* gvn)
  53   : Phase(Phase::Parser),
  54     _env(C->env()),
  55     _gvn((gvn != NULL) ? *gvn : *C->initial_gvn())
  56 {
  57   _exceptions = jvms->map()->next_exception();
  58   if (_exceptions != NULL)  jvms->map()->set_next_exception(NULL);
  59   set_jvms(jvms);
  60 #ifdef ASSERT
  61   if (_gvn.is_IterGVN() != NULL) {
  62     assert(_gvn.is_IterGVN()->delay_transform(), "Transformation must be delayed if IterGVN is used");
  63     // Save the initial size of _for_igvn worklist for verification (see ~GraphKit)
  64     _worklist_size = _gvn.C->for_igvn()->size();
  65   }
  66 #endif
  67 }
  68 
  69 // Private constructor for parser.
  70 GraphKit::GraphKit()
  71   : Phase(Phase::Parser),
  72     _env(C->env()),
  73     _gvn(*C->initial_gvn())
  74 {
  75   _exceptions = NULL;
  76   set_map(NULL);
  77   debug_only(_sp = -99);
  78   debug_only(set_bci(-99));
  79 }
  80 
  81 
  82 
  83 //---------------------------clean_stack---------------------------------------
  84 // Clear away rubbish from the stack area of the JVM state.
  85 // This destroys any arguments that may be waiting on the stack.
  86 void GraphKit::clean_stack(int from_sp) {
  87   SafePointNode* map      = this->map();
  88   JVMState*      jvms     = this->jvms();
  89   int            stk_size = jvms->stk_size();
  90   int            stkoff   = jvms->stkoff();
  91   Node*          top      = this->top();
  92   for (int i = from_sp; i < stk_size; i++) {
  93     if (map->in(stkoff + i) != top) {
  94       map->set_req(stkoff + i, top);
  95     }
  96   }
  97 }
  98 
  99 
 100 //--------------------------------sync_jvms-----------------------------------
 101 // Make sure our current jvms agrees with our parse state.
 102 JVMState* GraphKit::sync_jvms() const {
 103   JVMState* jvms = this->jvms();
 104   jvms->set_bci(bci());       // Record the new bci in the JVMState
 105   jvms->set_sp(sp());         // Record the new sp in the JVMState
 106   assert(jvms_in_sync(), "jvms is now in sync");
 107   return jvms;
 108 }
 109 
 110 //--------------------------------sync_jvms_for_reexecute---------------------
 111 // Make sure our current jvms agrees with our parse state.  This version
 112 // uses the reexecute_sp for reexecuting bytecodes.
 113 JVMState* GraphKit::sync_jvms_for_reexecute() {
 114   JVMState* jvms = this->jvms();
 115   jvms->set_bci(bci());          // Record the new bci in the JVMState
 116   jvms->set_sp(reexecute_sp());  // Record the new sp in the JVMState
 117   return jvms;
 118 }
 119 
 120 #ifdef ASSERT
 121 bool GraphKit::jvms_in_sync() const {
 122   Parse* parse = is_Parse();
 123   if (parse == NULL) {
 124     if (bci() !=      jvms()->bci())          return false;
 125     if (sp()  != (int)jvms()->sp())           return false;
 126     return true;
 127   }
 128   if (jvms()->method() != parse->method())    return false;
 129   if (jvms()->bci()    != parse->bci())       return false;
 130   int jvms_sp = jvms()->sp();
 131   if (jvms_sp          != parse->sp())        return false;
 132   int jvms_depth = jvms()->depth();
 133   if (jvms_depth       != parse->depth())     return false;
 134   return true;
 135 }
 136 
 137 // Local helper checks for special internal merge points
 138 // used to accumulate and merge exception states.
 139 // They are marked by the region's in(0) edge being the map itself.
 140 // Such merge points must never "escape" into the parser at large,
 141 // until they have been handed to gvn.transform.
 142 static bool is_hidden_merge(Node* reg) {
 143   if (reg == NULL)  return false;
 144   if (reg->is_Phi()) {
 145     reg = reg->in(0);
 146     if (reg == NULL)  return false;
 147   }
 148   return reg->is_Region() && reg->in(0) != NULL && reg->in(0)->is_Root();
 149 }
 150 
 151 void GraphKit::verify_map() const {
 152   if (map() == NULL)  return;  // null map is OK
 153   assert(map()->req() <= jvms()->endoff(), "no extra garbage on map");
 154   assert(!map()->has_exceptions(),    "call add_exception_states_from 1st");
 155   assert(!is_hidden_merge(control()), "call use_exception_state, not set_map");
 156 }
 157 
 158 void GraphKit::verify_exception_state(SafePointNode* ex_map) {
 159   assert(ex_map->next_exception() == NULL, "not already part of a chain");
 160   assert(has_saved_ex_oop(ex_map), "every exception state has an ex_oop");
 161 }
 162 #endif
 163 
 164 //---------------------------stop_and_kill_map---------------------------------
 165 // Set _map to NULL, signalling a stop to further bytecode execution.
 166 // First smash the current map's control to a constant, to mark it dead.
 167 void GraphKit::stop_and_kill_map() {
 168   SafePointNode* dead_map = stop();
 169   if (dead_map != NULL) {
 170     dead_map->disconnect_inputs(NULL, C); // Mark the map as killed.
 171     assert(dead_map->is_killed(), "must be so marked");
 172   }
 173 }
 174 
 175 
 176 //--------------------------------stopped--------------------------------------
 177 // Tell if _map is NULL, or control is top.
 178 bool GraphKit::stopped() {
 179   if (map() == NULL)           return true;
 180   else if (control() == top()) return true;
 181   else                         return false;
 182 }
 183 
 184 
 185 //-----------------------------has_ex_handler----------------------------------
 186 // Tell if this method or any caller method has exception handlers.
 187 bool GraphKit::has_ex_handler() {
 188   for (JVMState* jvmsp = jvms(); jvmsp != NULL; jvmsp = jvmsp->caller()) {
 189     if (jvmsp->has_method() && jvmsp->method()->has_exception_handlers()) {
 190       return true;
 191     }
 192   }
 193   return false;
 194 }
 195 
 196 //------------------------------save_ex_oop------------------------------------
 197 // Save an exception without blowing stack contents or other JVM state.
 198 void GraphKit::set_saved_ex_oop(SafePointNode* ex_map, Node* ex_oop) {
 199   assert(!has_saved_ex_oop(ex_map), "clear ex-oop before setting again");
 200   ex_map->add_req(ex_oop);
 201   debug_only(verify_exception_state(ex_map));
 202 }
 203 
 204 inline static Node* common_saved_ex_oop(SafePointNode* ex_map, bool clear_it) {
 205   assert(GraphKit::has_saved_ex_oop(ex_map), "ex_oop must be there");
 206   Node* ex_oop = ex_map->in(ex_map->req()-1);
 207   if (clear_it)  ex_map->del_req(ex_map->req()-1);
 208   return ex_oop;
 209 }
 210 
 211 //-----------------------------saved_ex_oop------------------------------------
 212 // Recover a saved exception from its map.
 213 Node* GraphKit::saved_ex_oop(SafePointNode* ex_map) {
 214   return common_saved_ex_oop(ex_map, false);
 215 }
 216 
 217 //--------------------------clear_saved_ex_oop---------------------------------
 218 // Erase a previously saved exception from its map.
 219 Node* GraphKit::clear_saved_ex_oop(SafePointNode* ex_map) {
 220   return common_saved_ex_oop(ex_map, true);
 221 }
 222 
 223 #ifdef ASSERT
 224 //---------------------------has_saved_ex_oop----------------------------------
 225 // Erase a previously saved exception from its map.
 226 bool GraphKit::has_saved_ex_oop(SafePointNode* ex_map) {
 227   return ex_map->req() == ex_map->jvms()->endoff()+1;
 228 }
 229 #endif
 230 
 231 //-------------------------make_exception_state--------------------------------
 232 // Turn the current JVM state into an exception state, appending the ex_oop.
 233 SafePointNode* GraphKit::make_exception_state(Node* ex_oop) {
 234   sync_jvms();
 235   SafePointNode* ex_map = stop();  // do not manipulate this map any more
 236   set_saved_ex_oop(ex_map, ex_oop);
 237   return ex_map;
 238 }
 239 
 240 
 241 //--------------------------add_exception_state--------------------------------
 242 // Add an exception to my list of exceptions.
 243 void GraphKit::add_exception_state(SafePointNode* ex_map) {
 244   if (ex_map == NULL || ex_map->control() == top()) {
 245     return;
 246   }
 247 #ifdef ASSERT
 248   verify_exception_state(ex_map);
 249   if (has_exceptions()) {
 250     assert(ex_map->jvms()->same_calls_as(_exceptions->jvms()), "all collected exceptions must come from the same place");
 251   }
 252 #endif
 253 
 254   // If there is already an exception of exactly this type, merge with it.
 255   // In particular, null-checks and other low-level exceptions common up here.
 256   Node*       ex_oop  = saved_ex_oop(ex_map);
 257   const Type* ex_type = _gvn.type(ex_oop);
 258   if (ex_oop == top()) {
 259     // No action needed.
 260     return;
 261   }
 262   assert(ex_type->isa_instptr(), "exception must be an instance");
 263   for (SafePointNode* e2 = _exceptions; e2 != NULL; e2 = e2->next_exception()) {
 264     const Type* ex_type2 = _gvn.type(saved_ex_oop(e2));
 265     // We check sp also because call bytecodes can generate exceptions
 266     // both before and after arguments are popped!
 267     if (ex_type2 == ex_type
 268         && e2->_jvms->sp() == ex_map->_jvms->sp()) {
 269       combine_exception_states(ex_map, e2);
 270       return;
 271     }
 272   }
 273 
 274   // No pre-existing exception of the same type.  Chain it on the list.
 275   push_exception_state(ex_map);
 276 }
 277 
 278 //-----------------------add_exception_states_from-----------------------------
 279 void GraphKit::add_exception_states_from(JVMState* jvms) {
 280   SafePointNode* ex_map = jvms->map()->next_exception();
 281   if (ex_map != NULL) {
 282     jvms->map()->set_next_exception(NULL);
 283     for (SafePointNode* next_map; ex_map != NULL; ex_map = next_map) {
 284       next_map = ex_map->next_exception();
 285       ex_map->set_next_exception(NULL);
 286       add_exception_state(ex_map);
 287     }
 288   }
 289 }
 290 
 291 //-----------------------transfer_exceptions_into_jvms-------------------------
 292 JVMState* GraphKit::transfer_exceptions_into_jvms() {
 293   if (map() == NULL) {
 294     // We need a JVMS to carry the exceptions, but the map has gone away.
 295     // Create a scratch JVMS, cloned from any of the exception states...
 296     if (has_exceptions()) {
 297       _map = _exceptions;
 298       _map = clone_map();
 299       _map->set_next_exception(NULL);
 300       clear_saved_ex_oop(_map);
 301       debug_only(verify_map());
 302     } else {
 303       // ...or created from scratch
 304       JVMState* jvms = new (C) JVMState(_method, NULL);
 305       jvms->set_bci(_bci);
 306       jvms->set_sp(_sp);
 307       jvms->set_map(new SafePointNode(TypeFunc::Parms, jvms));
 308       set_jvms(jvms);
 309       for (uint i = 0; i < map()->req(); i++)  map()->init_req(i, top());
 310       set_all_memory(top());
 311       while (map()->req() < jvms->endoff())  map()->add_req(top());
 312     }
 313     // (This is a kludge, in case you didn't notice.)
 314     set_control(top());
 315   }
 316   JVMState* jvms = sync_jvms();
 317   assert(!jvms->map()->has_exceptions(), "no exceptions on this map yet");
 318   jvms->map()->set_next_exception(_exceptions);
 319   _exceptions = NULL;   // done with this set of exceptions
 320   return jvms;
 321 }
 322 
 323 static inline void add_n_reqs(Node* dstphi, Node* srcphi) {
 324   assert(is_hidden_merge(dstphi), "must be a special merge node");
 325   assert(is_hidden_merge(srcphi), "must be a special merge node");
 326   uint limit = srcphi->req();
 327   for (uint i = PhiNode::Input; i < limit; i++) {
 328     dstphi->add_req(srcphi->in(i));
 329   }
 330 }
 331 static inline void add_one_req(Node* dstphi, Node* src) {
 332   assert(is_hidden_merge(dstphi), "must be a special merge node");
 333   assert(!is_hidden_merge(src), "must not be a special merge node");
 334   dstphi->add_req(src);
 335 }
 336 
 337 //-----------------------combine_exception_states------------------------------
 338 // This helper function combines exception states by building phis on a
 339 // specially marked state-merging region.  These regions and phis are
 340 // untransformed, and can build up gradually.  The region is marked by
 341 // having a control input of its exception map, rather than NULL.  Such
 342 // regions do not appear except in this function, and in use_exception_state.
 343 void GraphKit::combine_exception_states(SafePointNode* ex_map, SafePointNode* phi_map) {
 344   if (failing())  return;  // dying anyway...
 345   JVMState* ex_jvms = ex_map->_jvms;
 346   assert(ex_jvms->same_calls_as(phi_map->_jvms), "consistent call chains");
 347   assert(ex_jvms->stkoff() == phi_map->_jvms->stkoff(), "matching locals");
 348   assert(ex_jvms->sp() == phi_map->_jvms->sp(), "matching stack sizes");
 349   assert(ex_jvms->monoff() == phi_map->_jvms->monoff(), "matching JVMS");
 350   assert(ex_jvms->scloff() == phi_map->_jvms->scloff(), "matching scalar replaced objects");
 351   assert(ex_map->req() == phi_map->req(), "matching maps");
 352   uint tos = ex_jvms->stkoff() + ex_jvms->sp();
 353   Node*         hidden_merge_mark = root();
 354   Node*         region  = phi_map->control();
 355   MergeMemNode* phi_mem = phi_map->merged_memory();
 356   MergeMemNode* ex_mem  = ex_map->merged_memory();
 357   if (region->in(0) != hidden_merge_mark) {
 358     // The control input is not (yet) a specially-marked region in phi_map.
 359     // Make it so, and build some phis.
 360     region = new RegionNode(2);
 361     _gvn.set_type(region, Type::CONTROL);
 362     region->set_req(0, hidden_merge_mark);  // marks an internal ex-state
 363     region->init_req(1, phi_map->control());
 364     phi_map->set_control(region);
 365     Node* io_phi = PhiNode::make(region, phi_map->i_o(), Type::ABIO);
 366     record_for_igvn(io_phi);
 367     _gvn.set_type(io_phi, Type::ABIO);
 368     phi_map->set_i_o(io_phi);
 369     for (MergeMemStream mms(phi_mem); mms.next_non_empty(); ) {
 370       Node* m = mms.memory();
 371       Node* m_phi = PhiNode::make(region, m, Type::MEMORY, mms.adr_type(C));
 372       record_for_igvn(m_phi);
 373       _gvn.set_type(m_phi, Type::MEMORY);
 374       mms.set_memory(m_phi);
 375     }
 376   }
 377 
 378   // Either or both of phi_map and ex_map might already be converted into phis.
 379   Node* ex_control = ex_map->control();
 380   // if there is special marking on ex_map also, we add multiple edges from src
 381   bool add_multiple = (ex_control->in(0) == hidden_merge_mark);
 382   // how wide was the destination phi_map, originally?
 383   uint orig_width = region->req();
 384 
 385   if (add_multiple) {
 386     add_n_reqs(region, ex_control);
 387     add_n_reqs(phi_map->i_o(), ex_map->i_o());
 388   } else {
 389     // ex_map has no merges, so we just add single edges everywhere
 390     add_one_req(region, ex_control);
 391     add_one_req(phi_map->i_o(), ex_map->i_o());
 392   }
 393   for (MergeMemStream mms(phi_mem, ex_mem); mms.next_non_empty2(); ) {
 394     if (mms.is_empty()) {
 395       // get a copy of the base memory, and patch some inputs into it
 396       const TypePtr* adr_type = mms.adr_type(C);
 397       Node* phi = mms.force_memory()->as_Phi()->slice_memory(adr_type);
 398       assert(phi->as_Phi()->region() == mms.base_memory()->in(0), "");
 399       mms.set_memory(phi);
 400       // Prepare to append interesting stuff onto the newly sliced phi:
 401       while (phi->req() > orig_width)  phi->del_req(phi->req()-1);
 402     }
 403     // Append stuff from ex_map:
 404     if (add_multiple) {
 405       add_n_reqs(mms.memory(), mms.memory2());
 406     } else {
 407       add_one_req(mms.memory(), mms.memory2());
 408     }
 409   }
 410   uint limit = ex_map->req();
 411   for (uint i = TypeFunc::Parms; i < limit; i++) {
 412     // Skip everything in the JVMS after tos.  (The ex_oop follows.)
 413     if (i == tos)  i = ex_jvms->monoff();
 414     Node* src = ex_map->in(i);
 415     Node* dst = phi_map->in(i);
 416     if (src != dst) {
 417       PhiNode* phi;
 418       if (dst->in(0) != region) {
 419         dst = phi = PhiNode::make(region, dst, _gvn.type(dst));
 420         record_for_igvn(phi);
 421         _gvn.set_type(phi, phi->type());
 422         phi_map->set_req(i, dst);
 423         // Prepare to append interesting stuff onto the new phi:
 424         while (dst->req() > orig_width)  dst->del_req(dst->req()-1);
 425       } else {
 426         assert(dst->is_Phi(), "nobody else uses a hidden region");
 427         phi = dst->as_Phi();
 428       }
 429       if (add_multiple && src->in(0) == ex_control) {
 430         // Both are phis.
 431         add_n_reqs(dst, src);
 432       } else {
 433         while (dst->req() < region->req())  add_one_req(dst, src);
 434       }
 435       const Type* srctype = _gvn.type(src);
 436       if (phi->type() != srctype) {
 437         const Type* dsttype = phi->type()->meet_speculative(srctype);
 438         if (phi->type() != dsttype) {
 439           phi->set_type(dsttype);
 440           _gvn.set_type(phi, dsttype);
 441         }
 442       }
 443     }
 444   }
 445   phi_map->merge_replaced_nodes_with(ex_map);
 446 }
 447 
 448 //--------------------------use_exception_state--------------------------------
 449 Node* GraphKit::use_exception_state(SafePointNode* phi_map) {
 450   if (failing()) { stop(); return top(); }
 451   Node* region = phi_map->control();
 452   Node* hidden_merge_mark = root();
 453   assert(phi_map->jvms()->map() == phi_map, "sanity: 1-1 relation");
 454   Node* ex_oop = clear_saved_ex_oop(phi_map);
 455   if (region->in(0) == hidden_merge_mark) {
 456     // Special marking for internal ex-states.  Process the phis now.
 457     region->set_req(0, region);  // now it's an ordinary region
 458     set_jvms(phi_map->jvms());   // ...so now we can use it as a map
 459     // Note: Setting the jvms also sets the bci and sp.
 460     set_control(_gvn.transform(region));
 461     uint tos = jvms()->stkoff() + sp();
 462     for (uint i = 1; i < tos; i++) {
 463       Node* x = phi_map->in(i);
 464       if (x->in(0) == region) {
 465         assert(x->is_Phi(), "expected a special phi");
 466         phi_map->set_req(i, _gvn.transform(x));
 467       }
 468     }
 469     for (MergeMemStream mms(merged_memory()); mms.next_non_empty(); ) {
 470       Node* x = mms.memory();
 471       if (x->in(0) == region) {
 472         assert(x->is_Phi(), "nobody else uses a hidden region");
 473         mms.set_memory(_gvn.transform(x));
 474       }
 475     }
 476     if (ex_oop->in(0) == region) {
 477       assert(ex_oop->is_Phi(), "expected a special phi");
 478       ex_oop = _gvn.transform(ex_oop);
 479     }
 480   } else {
 481     set_jvms(phi_map->jvms());
 482   }
 483 
 484   assert(!is_hidden_merge(phi_map->control()), "hidden ex. states cleared");
 485   assert(!is_hidden_merge(phi_map->i_o()), "hidden ex. states cleared");
 486   return ex_oop;
 487 }
 488 
 489 //---------------------------------java_bc-------------------------------------
 490 Bytecodes::Code GraphKit::java_bc() const {
 491   ciMethod* method = this->method();
 492   int       bci    = this->bci();
 493   if (method != NULL && bci != InvocationEntryBci)
 494     return method->java_code_at_bci(bci);
 495   else
 496     return Bytecodes::_illegal;
 497 }
 498 
 499 void GraphKit::uncommon_trap_if_should_post_on_exceptions(Deoptimization::DeoptReason reason,
 500                                                           bool must_throw) {
 501     // if the exception capability is set, then we will generate code
 502     // to check the JavaThread.should_post_on_exceptions flag to see
 503     // if we actually need to report exception events (for this
 504     // thread).  If we don't need to report exception events, we will
 505     // take the normal fast path provided by add_exception_events.  If
 506     // exception event reporting is enabled for this thread, we will
 507     // take the uncommon_trap in the BuildCutout below.
 508 
 509     // first must access the should_post_on_exceptions_flag in this thread's JavaThread
 510     Node* jthread = _gvn.transform(new ThreadLocalNode());
 511     Node* adr = basic_plus_adr(top(), jthread, in_bytes(JavaThread::should_post_on_exceptions_flag_offset()));
 512     Node* should_post_flag = make_load(control(), adr, TypeInt::INT, T_INT, Compile::AliasIdxRaw, MemNode::unordered);
 513 
 514     // Test the should_post_on_exceptions_flag vs. 0
 515     Node* chk = _gvn.transform( new CmpINode(should_post_flag, intcon(0)) );
 516     Node* tst = _gvn.transform( new BoolNode(chk, BoolTest::eq) );
 517 
 518     // Branch to slow_path if should_post_on_exceptions_flag was true
 519     { BuildCutout unless(this, tst, PROB_MAX);
 520       // Do not try anything fancy if we're notifying the VM on every throw.
 521       // Cf. case Bytecodes::_athrow in parse2.cpp.
 522       uncommon_trap(reason, Deoptimization::Action_none,
 523                     (ciKlass*)NULL, (char*)NULL, must_throw);
 524     }
 525 
 526 }
 527 
 528 //------------------------------builtin_throw----------------------------------
 529 void GraphKit::builtin_throw(Deoptimization::DeoptReason reason, Node* arg) {
 530   bool must_throw = true;
 531 
 532   if (env()->jvmti_can_post_on_exceptions()) {
 533     // check if we must post exception events, take uncommon trap if so
 534     uncommon_trap_if_should_post_on_exceptions(reason, must_throw);
 535     // here if should_post_on_exceptions is false
 536     // continue on with the normal codegen
 537   }
 538 
 539   // If this particular condition has not yet happened at this
 540   // bytecode, then use the uncommon trap mechanism, and allow for
 541   // a future recompilation if several traps occur here.
 542   // If the throw is hot, try to use a more complicated inline mechanism
 543   // which keeps execution inside the compiled code.
 544   bool treat_throw_as_hot = false;
 545   ciMethodData* md = method()->method_data();
 546 
 547   if (ProfileTraps) {
 548     if (too_many_traps(reason)) {
 549       treat_throw_as_hot = true;
 550     }
 551     // (If there is no MDO at all, assume it is early in
 552     // execution, and that any deopts are part of the
 553     // startup transient, and don't need to be remembered.)
 554 
 555     // Also, if there is a local exception handler, treat all throws
 556     // as hot if there has been at least one in this method.
 557     if (C->trap_count(reason) != 0
 558         && method()->method_data()->trap_count(reason) != 0
 559         && has_ex_handler()) {
 560         treat_throw_as_hot = true;
 561     }
 562   }
 563 
 564   // If this throw happens frequently, an uncommon trap might cause
 565   // a performance pothole.  If there is a local exception handler,
 566   // and if this particular bytecode appears to be deoptimizing often,
 567   // let us handle the throw inline, with a preconstructed instance.
 568   // Note:   If the deopt count has blown up, the uncommon trap
 569   // runtime is going to flush this nmethod, not matter what.
 570   if (treat_throw_as_hot
 571       && (!StackTraceInThrowable || OmitStackTraceInFastThrow)) {
 572     // If the throw is local, we use a pre-existing instance and
 573     // punt on the backtrace.  This would lead to a missing backtrace
 574     // (a repeat of 4292742) if the backtrace object is ever asked
 575     // for its backtrace.
 576     // Fixing this remaining case of 4292742 requires some flavor of
 577     // escape analysis.  Leave that for the future.
 578     ciInstance* ex_obj = NULL;
 579     switch (reason) {
 580     case Deoptimization::Reason_null_check:
 581       ex_obj = env()->NullPointerException_instance();
 582       break;
 583     case Deoptimization::Reason_div0_check:
 584       ex_obj = env()->ArithmeticException_instance();
 585       break;
 586     case Deoptimization::Reason_range_check:
 587       ex_obj = env()->ArrayIndexOutOfBoundsException_instance();
 588       break;
 589     case Deoptimization::Reason_class_check:
 590       if (java_bc() == Bytecodes::_aastore) {
 591         ex_obj = env()->ArrayStoreException_instance();
 592       } else {
 593         ex_obj = env()->ClassCastException_instance();
 594       }
 595       break;
 596     default:
 597       break;
 598     }
 599     if (failing()) { stop(); return; }  // exception allocation might fail
 600     if (ex_obj != NULL) {
 601       // Cheat with a preallocated exception object.
 602       if (C->log() != NULL)
 603         C->log()->elem("hot_throw preallocated='1' reason='%s'",
 604                        Deoptimization::trap_reason_name(reason));
 605       const TypeInstPtr* ex_con  = TypeInstPtr::make(ex_obj);
 606       Node*              ex_node = _gvn.transform(ConNode::make(ex_con));
 607 
 608       // Clear the detail message of the preallocated exception object.
 609       // Weblogic sometimes mutates the detail message of exceptions
 610       // using reflection.
 611       int offset = java_lang_Throwable::get_detailMessage_offset();
 612       const TypePtr* adr_typ = ex_con->add_offset(offset);
 613 
 614       Node *adr = basic_plus_adr(ex_node, ex_node, offset);
 615       const TypeOopPtr* val_type = TypeOopPtr::make_from_klass(env()->String_klass());
 616       // Conservatively release stores of object references.
 617       Node *store = store_oop_to_object(control(), ex_node, adr, adr_typ, null(), val_type, T_OBJECT, MemNode::release);
 618 
 619       add_exception_state(make_exception_state(ex_node));
 620       return;
 621     }
 622   }
 623 
 624   // %%% Maybe add entry to OptoRuntime which directly throws the exc.?
 625   // It won't be much cheaper than bailing to the interp., since we'll
 626   // have to pass up all the debug-info, and the runtime will have to
 627   // create the stack trace.
 628 
 629   // Usual case:  Bail to interpreter.
 630   // Reserve the right to recompile if we haven't seen anything yet.
 631 
 632   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? C->method() : NULL;
 633   Deoptimization::DeoptAction action = Deoptimization::Action_maybe_recompile;
 634   if (treat_throw_as_hot
 635       && (method()->method_data()->trap_recompiled_at(bci(), m)
 636           || C->too_many_traps(reason))) {
 637     // We cannot afford to take more traps here.  Suffer in the interpreter.
 638     if (C->log() != NULL)
 639       C->log()->elem("hot_throw preallocated='0' reason='%s' mcount='%d'",
 640                      Deoptimization::trap_reason_name(reason),
 641                      C->trap_count(reason));
 642     action = Deoptimization::Action_none;
 643   }
 644 
 645   // "must_throw" prunes the JVM state to include only the stack, if there
 646   // are no local exception handlers.  This should cut down on register
 647   // allocation time and code size, by drastically reducing the number
 648   // of in-edges on the call to the uncommon trap.
 649 
 650   uncommon_trap(reason, action, (ciKlass*)NULL, (char*)NULL, must_throw);
 651 }
 652 
 653 
 654 //----------------------------PreserveJVMState---------------------------------
 655 PreserveJVMState::PreserveJVMState(GraphKit* kit, bool clone_map) {
 656   debug_only(kit->verify_map());
 657   _kit    = kit;
 658   _map    = kit->map();   // preserve the map
 659   _sp     = kit->sp();
 660   kit->set_map(clone_map ? kit->clone_map() : NULL);
 661 #ifdef ASSERT
 662   _bci    = kit->bci();
 663   Parse* parser = kit->is_Parse();
 664   int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo();
 665   _block  = block;
 666 #endif
 667 }
 668 PreserveJVMState::~PreserveJVMState() {
 669   GraphKit* kit = _kit;
 670 #ifdef ASSERT
 671   assert(kit->bci() == _bci, "bci must not shift");
 672   Parse* parser = kit->is_Parse();
 673   int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo();
 674   assert(block == _block,    "block must not shift");
 675 #endif
 676   kit->set_map(_map);
 677   kit->set_sp(_sp);
 678 }
 679 
 680 
 681 //-----------------------------BuildCutout-------------------------------------
 682 BuildCutout::BuildCutout(GraphKit* kit, Node* p, float prob, float cnt)
 683   : PreserveJVMState(kit)
 684 {
 685   assert(p->is_Con() || p->is_Bool(), "test must be a bool");
 686   SafePointNode* outer_map = _map;   // preserved map is caller's
 687   SafePointNode* inner_map = kit->map();
 688   IfNode* iff = kit->create_and_map_if(outer_map->control(), p, prob, cnt);
 689   outer_map->set_control(kit->gvn().transform( new IfTrueNode(iff) ));
 690   inner_map->set_control(kit->gvn().transform( new IfFalseNode(iff) ));
 691 }
 692 BuildCutout::~BuildCutout() {
 693   GraphKit* kit = _kit;
 694   assert(kit->stopped(), "cutout code must stop, throw, return, etc.");
 695 }
 696 
 697 //---------------------------PreserveReexecuteState----------------------------
 698 PreserveReexecuteState::PreserveReexecuteState(GraphKit* kit) {
 699   assert(!kit->stopped(), "must call stopped() before");
 700   _kit    =    kit;
 701   _sp     =    kit->sp();
 702   _reexecute = kit->jvms()->_reexecute;
 703 }
 704 PreserveReexecuteState::~PreserveReexecuteState() {
 705   if (_kit->stopped()) return;
 706   _kit->jvms()->_reexecute = _reexecute;
 707   _kit->set_sp(_sp);
 708 }
 709 
 710 //------------------------------clone_map--------------------------------------
 711 // Implementation of PreserveJVMState
 712 //
 713 // Only clone_map(...) here. If this function is only used in the
 714 // PreserveJVMState class we may want to get rid of this extra
 715 // function eventually and do it all there.
 716 
 717 SafePointNode* GraphKit::clone_map() {
 718   if (map() == NULL)  return NULL;
 719 
 720   // Clone the memory edge first
 721   Node* mem = MergeMemNode::make(map()->memory());
 722   gvn().set_type_bottom(mem);
 723 
 724   SafePointNode *clonemap = (SafePointNode*)map()->clone();
 725   JVMState* jvms = this->jvms();
 726   JVMState* clonejvms = jvms->clone_shallow(C);
 727   clonemap->set_memory(mem);
 728   clonemap->set_jvms(clonejvms);
 729   clonejvms->set_map(clonemap);
 730   record_for_igvn(clonemap);
 731   gvn().set_type_bottom(clonemap);
 732   return clonemap;
 733 }
 734 
 735 
 736 //-----------------------------set_map_clone-----------------------------------
 737 void GraphKit::set_map_clone(SafePointNode* m) {
 738   _map = m;
 739   _map = clone_map();
 740   _map->set_next_exception(NULL);
 741   debug_only(verify_map());
 742 }
 743 
 744 
 745 //----------------------------kill_dead_locals---------------------------------
 746 // Detect any locals which are known to be dead, and force them to top.
 747 void GraphKit::kill_dead_locals() {
 748   // Consult the liveness information for the locals.  If any
 749   // of them are unused, then they can be replaced by top().  This
 750   // should help register allocation time and cut down on the size
 751   // of the deoptimization information.
 752 
 753   // This call is made from many of the bytecode handling
 754   // subroutines called from the Big Switch in do_one_bytecode.
 755   // Every bytecode which might include a slow path is responsible
 756   // for killing its dead locals.  The more consistent we
 757   // are about killing deads, the fewer useless phis will be
 758   // constructed for them at various merge points.
 759 
 760   // bci can be -1 (InvocationEntryBci).  We return the entry
 761   // liveness for the method.
 762 
 763   if (method() == NULL || method()->code_size() == 0) {
 764     // We are building a graph for a call to a native method.
 765     // All locals are live.
 766     return;
 767   }
 768 
 769   ResourceMark rm;
 770 
 771   // Consult the liveness information for the locals.  If any
 772   // of them are unused, then they can be replaced by top().  This
 773   // should help register allocation time and cut down on the size
 774   // of the deoptimization information.
 775   MethodLivenessResult live_locals = method()->liveness_at_bci(bci());
 776 
 777   int len = (int)live_locals.size();
 778   assert(len <= jvms()->loc_size(), "too many live locals");
 779   for (int local = 0; local < len; local++) {
 780     if (!live_locals.at(local)) {
 781       set_local(local, top());
 782     }
 783   }
 784 }
 785 
 786 #ifdef ASSERT
 787 //-------------------------dead_locals_are_killed------------------------------
 788 // Return true if all dead locals are set to top in the map.
 789 // Used to assert "clean" debug info at various points.
 790 bool GraphKit::dead_locals_are_killed() {
 791   if (method() == NULL || method()->code_size() == 0) {
 792     // No locals need to be dead, so all is as it should be.
 793     return true;
 794   }
 795 
 796   // Make sure somebody called kill_dead_locals upstream.
 797   ResourceMark rm;
 798   for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) {
 799     if (jvms->loc_size() == 0)  continue;  // no locals to consult
 800     SafePointNode* map = jvms->map();
 801     ciMethod* method = jvms->method();
 802     int       bci    = jvms->bci();
 803     if (jvms == this->jvms()) {
 804       bci = this->bci();  // it might not yet be synched
 805     }
 806     MethodLivenessResult live_locals = method->liveness_at_bci(bci);
 807     int len = (int)live_locals.size();
 808     if (!live_locals.is_valid() || len == 0)
 809       // This method is trivial, or is poisoned by a breakpoint.
 810       return true;
 811     assert(len == jvms->loc_size(), "live map consistent with locals map");
 812     for (int local = 0; local < len; local++) {
 813       if (!live_locals.at(local) && map->local(jvms, local) != top()) {
 814         if (PrintMiscellaneous && (Verbose || WizardMode)) {
 815           tty->print_cr("Zombie local %d: ", local);
 816           jvms->dump();
 817         }
 818         return false;
 819       }
 820     }
 821   }
 822   return true;
 823 }
 824 
 825 #endif //ASSERT
 826 
 827 // Helper function for enforcing certain bytecodes to reexecute if
 828 // deoptimization happens
 829 static bool should_reexecute_implied_by_bytecode(JVMState *jvms, bool is_anewarray) {
 830   ciMethod* cur_method = jvms->method();
 831   int       cur_bci   = jvms->bci();
 832   if (cur_method != NULL && cur_bci != InvocationEntryBci) {
 833     Bytecodes::Code code = cur_method->java_code_at_bci(cur_bci);
 834     return Interpreter::bytecode_should_reexecute(code) ||
 835            (is_anewarray && (code == Bytecodes::_multianewarray));
 836     // Reexecute _multianewarray bytecode which was replaced with
 837     // sequence of [a]newarray. See Parse::do_multianewarray().
 838     //
 839     // Note: interpreter should not have it set since this optimization
 840     // is limited by dimensions and guarded by flag so in some cases
 841     // multianewarray() runtime calls will be generated and
 842     // the bytecode should not be reexecutes (stack will not be reset).
 843   } else {
 844     return false;
 845   }
 846 }
 847 
 848 // Helper function for adding JVMState and debug information to node
 849 void GraphKit::add_safepoint_edges(SafePointNode* call, bool must_throw) {
 850   // Add the safepoint edges to the call (or other safepoint).
 851 
 852   // Make sure dead locals are set to top.  This
 853   // should help register allocation time and cut down on the size
 854   // of the deoptimization information.
 855   assert(dead_locals_are_killed(), "garbage in debug info before safepoint");
 856 
 857   // Walk the inline list to fill in the correct set of JVMState's
 858   // Also fill in the associated edges for each JVMState.
 859 
 860   // If the bytecode needs to be reexecuted we need to put
 861   // the arguments back on the stack.
 862   const bool should_reexecute = jvms()->should_reexecute();
 863   JVMState* youngest_jvms = should_reexecute ? sync_jvms_for_reexecute() : sync_jvms();
 864 
 865   // NOTE: set_bci (called from sync_jvms) might reset the reexecute bit to
 866   // undefined if the bci is different.  This is normal for Parse but it
 867   // should not happen for LibraryCallKit because only one bci is processed.
 868   assert(!is_LibraryCallKit() || (jvms()->should_reexecute() == should_reexecute),
 869          "in LibraryCallKit the reexecute bit should not change");
 870 
 871   // If we are guaranteed to throw, we can prune everything but the
 872   // input to the current bytecode.
 873   bool can_prune_locals = false;
 874   uint stack_slots_not_pruned = 0;
 875   int inputs = 0, depth = 0;
 876   if (must_throw) {
 877     assert(method() == youngest_jvms->method(), "sanity");
 878     if (compute_stack_effects(inputs, depth)) {
 879       can_prune_locals = true;
 880       stack_slots_not_pruned = inputs;
 881     }
 882   }
 883 
 884   if (env()->should_retain_local_variables()) {
 885     // At any safepoint, this method can get breakpointed, which would
 886     // then require an immediate deoptimization.
 887     can_prune_locals = false;  // do not prune locals
 888     stack_slots_not_pruned = 0;
 889   }
 890 
 891   // do not scribble on the input jvms
 892   JVMState* out_jvms = youngest_jvms->clone_deep(C);
 893   call->set_jvms(out_jvms); // Start jvms list for call node
 894 
 895   // For a known set of bytecodes, the interpreter should reexecute them if
 896   // deoptimization happens. We set the reexecute state for them here
 897   if (out_jvms->is_reexecute_undefined() && //don't change if already specified
 898       should_reexecute_implied_by_bytecode(out_jvms, call->is_AllocateArray())) {
 899     out_jvms->set_should_reexecute(true); //NOTE: youngest_jvms not changed
 900   }
 901 
 902   // Presize the call:
 903   DEBUG_ONLY(uint non_debug_edges = call->req());
 904   call->add_req_batch(top(), youngest_jvms->debug_depth());
 905   assert(call->req() == non_debug_edges + youngest_jvms->debug_depth(), "");
 906 
 907   // Set up edges so that the call looks like this:
 908   //  Call [state:] ctl io mem fptr retadr
 909   //       [parms:] parm0 ... parmN
 910   //       [root:]  loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN
 911   //    [...mid:]   loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN [...]
 912   //       [young:] loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN
 913   // Note that caller debug info precedes callee debug info.
 914 
 915   // Fill pointer walks backwards from "young:" to "root:" in the diagram above:
 916   uint debug_ptr = call->req();
 917 
 918   // Loop over the map input edges associated with jvms, add them
 919   // to the call node, & reset all offsets to match call node array.
 920   for (JVMState* in_jvms = youngest_jvms; in_jvms != NULL; ) {
 921     uint debug_end   = debug_ptr;
 922     uint debug_start = debug_ptr - in_jvms->debug_size();
 923     debug_ptr = debug_start;  // back up the ptr
 924 
 925     uint p = debug_start;  // walks forward in [debug_start, debug_end)
 926     uint j, k, l;
 927     SafePointNode* in_map = in_jvms->map();
 928     out_jvms->set_map(call);
 929 
 930     if (can_prune_locals) {
 931       assert(in_jvms->method() == out_jvms->method(), "sanity");
 932       // If the current throw can reach an exception handler in this JVMS,
 933       // then we must keep everything live that can reach that handler.
 934       // As a quick and dirty approximation, we look for any handlers at all.
 935       if (in_jvms->method()->has_exception_handlers()) {
 936         can_prune_locals = false;
 937       }
 938     }
 939 
 940     // Add the Locals
 941     k = in_jvms->locoff();
 942     l = in_jvms->loc_size();
 943     out_jvms->set_locoff(p);
 944     if (!can_prune_locals) {
 945       for (j = 0; j < l; j++)
 946         call->set_req(p++, in_map->in(k+j));
 947     } else {
 948       p += l;  // already set to top above by add_req_batch
 949     }
 950 
 951     // Add the Expression Stack
 952     k = in_jvms->stkoff();
 953     l = in_jvms->sp();
 954     out_jvms->set_stkoff(p);
 955     if (!can_prune_locals) {
 956       for (j = 0; j < l; j++)
 957         call->set_req(p++, in_map->in(k+j));
 958     } else if (can_prune_locals && stack_slots_not_pruned != 0) {
 959       // Divide stack into {S0,...,S1}, where S0 is set to top.
 960       uint s1 = stack_slots_not_pruned;
 961       stack_slots_not_pruned = 0;  // for next iteration
 962       if (s1 > l)  s1 = l;
 963       uint s0 = l - s1;
 964       p += s0;  // skip the tops preinstalled by add_req_batch
 965       for (j = s0; j < l; j++)
 966         call->set_req(p++, in_map->in(k+j));
 967     } else {
 968       p += l;  // already set to top above by add_req_batch
 969     }
 970 
 971     // Add the Monitors
 972     k = in_jvms->monoff();
 973     l = in_jvms->mon_size();
 974     out_jvms->set_monoff(p);
 975     for (j = 0; j < l; j++)
 976       call->set_req(p++, in_map->in(k+j));
 977 
 978     // Copy any scalar object fields.
 979     k = in_jvms->scloff();
 980     l = in_jvms->scl_size();
 981     out_jvms->set_scloff(p);
 982     for (j = 0; j < l; j++)
 983       call->set_req(p++, in_map->in(k+j));
 984 
 985     // Finish the new jvms.
 986     out_jvms->set_endoff(p);
 987 
 988     assert(out_jvms->endoff()     == debug_end,             "fill ptr must match");
 989     assert(out_jvms->depth()      == in_jvms->depth(),      "depth must match");
 990     assert(out_jvms->loc_size()   == in_jvms->loc_size(),   "size must match");
 991     assert(out_jvms->mon_size()   == in_jvms->mon_size(),   "size must match");
 992     assert(out_jvms->scl_size()   == in_jvms->scl_size(),   "size must match");
 993     assert(out_jvms->debug_size() == in_jvms->debug_size(), "size must match");
 994 
 995     // Update the two tail pointers in parallel.
 996     out_jvms = out_jvms->caller();
 997     in_jvms  = in_jvms->caller();
 998   }
 999 
1000   assert(debug_ptr == non_debug_edges, "debug info must fit exactly");
1001 
1002   // Test the correctness of JVMState::debug_xxx accessors:
1003   assert(call->jvms()->debug_start() == non_debug_edges, "");
1004   assert(call->jvms()->debug_end()   == call->req(), "");
1005   assert(call->jvms()->debug_depth() == call->req() - non_debug_edges, "");
1006 }
1007 
1008 bool GraphKit::compute_stack_effects(int& inputs, int& depth) {
1009   Bytecodes::Code code = java_bc();
1010   if (code == Bytecodes::_wide) {
1011     code = method()->java_code_at_bci(bci() + 1);
1012   }
1013 
1014   BasicType rtype = T_ILLEGAL;
1015   int       rsize = 0;
1016 
1017   if (code != Bytecodes::_illegal) {
1018     depth = Bytecodes::depth(code); // checkcast=0, athrow=-1
1019     rtype = Bytecodes::result_type(code); // checkcast=P, athrow=V
1020     if (rtype < T_CONFLICT)
1021       rsize = type2size[rtype];
1022   }
1023 
1024   switch (code) {
1025   case Bytecodes::_illegal:
1026     return false;
1027 
1028   case Bytecodes::_ldc:
1029   case Bytecodes::_ldc_w:
1030   case Bytecodes::_ldc2_w:
1031     inputs = 0;
1032     break;
1033 
1034   case Bytecodes::_dup:         inputs = 1;  break;
1035   case Bytecodes::_dup_x1:      inputs = 2;  break;
1036   case Bytecodes::_dup_x2:      inputs = 3;  break;
1037   case Bytecodes::_dup2:        inputs = 2;  break;
1038   case Bytecodes::_dup2_x1:     inputs = 3;  break;
1039   case Bytecodes::_dup2_x2:     inputs = 4;  break;
1040   case Bytecodes::_swap:        inputs = 2;  break;
1041   case Bytecodes::_arraylength: inputs = 1;  break;
1042 
1043   case Bytecodes::_getstatic:
1044   case Bytecodes::_putstatic:
1045   case Bytecodes::_getfield:
1046   case Bytecodes::_putfield:
1047     {
1048       bool ignored_will_link;
1049       ciField* field = method()->get_field_at_bci(bci(), ignored_will_link);
1050       int      size  = field->type()->size();
1051       bool is_get = (depth >= 0), is_static = (depth & 1);
1052       inputs = (is_static ? 0 : 1);
1053       if (is_get) {
1054         depth = size - inputs;
1055       } else {
1056         inputs += size;        // putxxx pops the value from the stack
1057         depth = - inputs;
1058       }
1059     }
1060     break;
1061 
1062   case Bytecodes::_invokevirtual:
1063   case Bytecodes::_invokespecial:
1064   case Bytecodes::_invokestatic:
1065   case Bytecodes::_invokedynamic:
1066   case Bytecodes::_invokeinterface:
1067     {
1068       bool ignored_will_link;
1069       ciSignature* declared_signature = NULL;
1070       ciMethod* ignored_callee = method()->get_method_at_bci(bci(), ignored_will_link, &declared_signature);
1071       assert(declared_signature != NULL, "cannot be null");
1072       inputs   = declared_signature->arg_size_for_bc(code);
1073       int size = declared_signature->return_type()->size();
1074       depth = size - inputs;
1075     }
1076     break;
1077 
1078   case Bytecodes::_multianewarray:
1079     {
1080       ciBytecodeStream iter(method());
1081       iter.reset_to_bci(bci());
1082       iter.next();
1083       inputs = iter.get_dimensions();
1084       assert(rsize == 1, "");
1085       depth = rsize - inputs;
1086     }
1087     break;
1088 
1089   case Bytecodes::_withfield: {
1090     bool ignored_will_link;
1091     ciField* field = method()->get_field_at_bci(bci(), ignored_will_link);
1092     int      size  = field->type()->size();
1093     inputs = size+1;
1094     depth = rsize - inputs;
1095     break;
1096   }
1097 
1098   case Bytecodes::_ireturn:
1099   case Bytecodes::_lreturn:
1100   case Bytecodes::_freturn:
1101   case Bytecodes::_dreturn:
1102   case Bytecodes::_areturn:
1103     assert(rsize == -depth, "");
1104     inputs = rsize;
1105     break;
1106 
1107   case Bytecodes::_jsr:
1108   case Bytecodes::_jsr_w:
1109     inputs = 0;
1110     depth  = 1;                  // S.B. depth=1, not zero
1111     break;
1112 
1113   default:
1114     // bytecode produces a typed result
1115     inputs = rsize - depth;
1116     assert(inputs >= 0, "");
1117     break;
1118   }
1119 
1120 #ifdef ASSERT
1121   // spot check
1122   int outputs = depth + inputs;
1123   assert(outputs >= 0, "sanity");
1124   switch (code) {
1125   case Bytecodes::_checkcast: assert(inputs == 1 && outputs == 1, ""); break;
1126   case Bytecodes::_athrow:    assert(inputs == 1 && outputs == 0, ""); break;
1127   case Bytecodes::_aload_0:   assert(inputs == 0 && outputs == 1, ""); break;
1128   case Bytecodes::_return:    assert(inputs == 0 && outputs == 0, ""); break;
1129   case Bytecodes::_drem:      assert(inputs == 4 && outputs == 2, ""); break;
1130   default:                    break;
1131   }
1132 #endif //ASSERT
1133 
1134   return true;
1135 }
1136 
1137 
1138 
1139 //------------------------------basic_plus_adr---------------------------------
1140 Node* GraphKit::basic_plus_adr(Node* base, Node* ptr, Node* offset) {
1141   // short-circuit a common case
1142   if (offset == intcon(0))  return ptr;
1143   return _gvn.transform( new AddPNode(base, ptr, offset) );
1144 }
1145 
1146 Node* GraphKit::ConvI2L(Node* offset) {
1147   // short-circuit a common case
1148   jint offset_con = find_int_con(offset, Type::OffsetBot);
1149   if (offset_con != Type::OffsetBot) {
1150     return longcon((jlong) offset_con);
1151   }
1152   return _gvn.transform( new ConvI2LNode(offset));
1153 }
1154 
1155 Node* GraphKit::ConvI2UL(Node* offset) {
1156   juint offset_con = (juint) find_int_con(offset, Type::OffsetBot);
1157   if (offset_con != (juint) Type::OffsetBot) {
1158     return longcon((julong) offset_con);
1159   }
1160   Node* conv = _gvn.transform( new ConvI2LNode(offset));
1161   Node* mask = _gvn.transform(ConLNode::make((julong) max_juint));
1162   return _gvn.transform( new AndLNode(conv, mask) );
1163 }
1164 
1165 Node* GraphKit::ConvL2I(Node* offset) {
1166   // short-circuit a common case
1167   jlong offset_con = find_long_con(offset, (jlong)Type::OffsetBot);
1168   if (offset_con != (jlong)Type::OffsetBot) {
1169     return intcon((int) offset_con);
1170   }
1171   return _gvn.transform( new ConvL2INode(offset));
1172 }
1173 
1174 //-------------------------load_object_klass-----------------------------------
1175 Node* GraphKit::load_object_klass(Node* obj) {
1176   // Special-case a fresh allocation to avoid building nodes:
1177   Node* akls = AllocateNode::Ideal_klass(obj, &_gvn);
1178   if (akls != NULL)  return akls;
1179   Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes());
1180   return _gvn.transform(LoadKlassNode::make(_gvn, NULL, immutable_memory(), k_adr, TypeInstPtr::KLASS));
1181 }
1182 
1183 //-------------------------load_array_length-----------------------------------
1184 Node* GraphKit::load_array_length(Node* array) {
1185   // Special-case a fresh allocation to avoid building nodes:
1186   AllocateArrayNode* alloc = AllocateArrayNode::Ideal_array_allocation(array, &_gvn);
1187   Node *alen;
1188   if (alloc == NULL) {
1189     Node *r_adr = basic_plus_adr(array, arrayOopDesc::length_offset_in_bytes());
1190     alen = _gvn.transform( new LoadRangeNode(0, immutable_memory(), r_adr, TypeInt::POS));
1191   } else {
1192     alen = alloc->Ideal_length();
1193     Node* ccast = alloc->make_ideal_length(_gvn.type(array)->is_oopptr(), &_gvn);
1194     if (ccast != alen) {
1195       alen = _gvn.transform(ccast);
1196     }
1197   }
1198   return alen;
1199 }
1200 
1201 //------------------------------do_null_check----------------------------------
1202 // Helper function to do a NULL pointer check.  Returned value is
1203 // the incoming address with NULL casted away.  You are allowed to use the
1204 // not-null value only if you are control dependent on the test.
1205 #ifndef PRODUCT
1206 extern int explicit_null_checks_inserted,
1207            explicit_null_checks_elided;
1208 #endif
1209 Node* GraphKit::null_check_common(Node* value, BasicType type,
1210                                   // optional arguments for variations:
1211                                   bool assert_null,
1212                                   Node* *null_control,
1213                                   bool speculative) {
1214   assert(!assert_null || null_control == NULL, "not both at once");
1215   if (stopped())  return top();
1216   NOT_PRODUCT(explicit_null_checks_inserted++);
1217 
1218   // Construct NULL check
1219   Node *chk = NULL;
1220   switch(type) {
1221     case T_LONG   : chk = new CmpLNode(value, _gvn.zerocon(T_LONG)); break;
1222     case T_INT    : chk = new CmpINode(value, _gvn.intcon(0)); break;
1223     case T_VALUETYPE : // fall through
1224     case T_ARRAY  : // fall through
1225       type = T_OBJECT;  // simplify further tests
1226     case T_OBJECT : {
1227       const Type *t = _gvn.type( value );
1228 
1229       const TypeOopPtr* tp = t->isa_oopptr();
1230       if (tp != NULL && tp->klass() != NULL && !tp->klass()->is_loaded()
1231           // Only for do_null_check, not any of its siblings:
1232           && !assert_null && null_control == NULL) {
1233         // Usually, any field access or invocation on an unloaded oop type
1234         // will simply fail to link, since the statically linked class is
1235         // likely also to be unloaded.  However, in -Xcomp mode, sometimes
1236         // the static class is loaded but the sharper oop type is not.
1237         // Rather than checking for this obscure case in lots of places,
1238         // we simply observe that a null check on an unloaded class
1239         // will always be followed by a nonsense operation, so we
1240         // can just issue the uncommon trap here.
1241         // Our access to the unloaded class will only be correct
1242         // after it has been loaded and initialized, which requires
1243         // a trip through the interpreter.
1244 #ifndef PRODUCT
1245         if (WizardMode) { tty->print("Null check of unloaded "); tp->klass()->print(); tty->cr(); }
1246 #endif
1247         uncommon_trap(Deoptimization::Reason_unloaded,
1248                       Deoptimization::Action_reinterpret,
1249                       tp->klass(), "!loaded");
1250         return top();
1251       }
1252 
1253       if (assert_null) {
1254         // See if the type is contained in NULL_PTR.
1255         // If so, then the value is already null.
1256         if (t->higher_equal(TypePtr::NULL_PTR)) {
1257           NOT_PRODUCT(explicit_null_checks_elided++);
1258           return value;           // Elided null assert quickly!
1259         }
1260       } else {
1261         // See if mixing in the NULL pointer changes type.
1262         // If so, then the NULL pointer was not allowed in the original
1263         // type.  In other words, "value" was not-null.
1264         if (t->meet(TypePtr::NULL_PTR) != t->remove_speculative()) {
1265           // same as: if (!TypePtr::NULL_PTR->higher_equal(t)) ...
1266           NOT_PRODUCT(explicit_null_checks_elided++);
1267           return value;           // Elided null check quickly!
1268         }
1269       }
1270       chk = new CmpPNode( value, null() );
1271       break;
1272     }
1273 
1274     default:
1275       fatal("unexpected type: %s", type2name(type));
1276   }
1277   assert(chk != NULL, "sanity check");
1278   chk = _gvn.transform(chk);
1279 
1280   BoolTest::mask btest = assert_null ? BoolTest::eq : BoolTest::ne;
1281   BoolNode *btst = new BoolNode( chk, btest);
1282   Node   *tst = _gvn.transform( btst );
1283 
1284   //-----------
1285   // if peephole optimizations occurred, a prior test existed.
1286   // If a prior test existed, maybe it dominates as we can avoid this test.
1287   if (tst != btst && type == T_OBJECT) {
1288     // At this point we want to scan up the CFG to see if we can
1289     // find an identical test (and so avoid this test altogether).
1290     Node *cfg = control();
1291     int depth = 0;
1292     while( depth < 16 ) {       // Limit search depth for speed
1293       if( cfg->Opcode() == Op_IfTrue &&
1294           cfg->in(0)->in(1) == tst ) {
1295         // Found prior test.  Use "cast_not_null" to construct an identical
1296         // CastPP (and hence hash to) as already exists for the prior test.
1297         // Return that casted value.
1298         if (assert_null) {
1299           replace_in_map(value, null());
1300           return null();  // do not issue the redundant test
1301         }
1302         Node *oldcontrol = control();
1303         set_control(cfg);
1304         Node *res = cast_not_null(value);
1305         set_control(oldcontrol);
1306         NOT_PRODUCT(explicit_null_checks_elided++);
1307         return res;
1308       }
1309       cfg = IfNode::up_one_dom(cfg, /*linear_only=*/ true);
1310       if (cfg == NULL)  break;  // Quit at region nodes
1311       depth++;
1312     }
1313   }
1314 
1315   //-----------
1316   // Branch to failure if null
1317   float ok_prob = PROB_MAX;  // a priori estimate:  nulls never happen
1318   Deoptimization::DeoptReason reason;
1319   if (assert_null) {
1320     reason = Deoptimization::reason_null_assert(speculative);
1321   } else if (type == T_OBJECT) {
1322     reason = Deoptimization::reason_null_check(speculative);
1323   } else {
1324     reason = Deoptimization::Reason_div0_check;
1325   }
1326   // %%% Since Reason_unhandled is not recorded on a per-bytecode basis,
1327   // ciMethodData::has_trap_at will return a conservative -1 if any
1328   // must-be-null assertion has failed.  This could cause performance
1329   // problems for a method after its first do_null_assert failure.
1330   // Consider using 'Reason_class_check' instead?
1331 
1332   // To cause an implicit null check, we set the not-null probability
1333   // to the maximum (PROB_MAX).  For an explicit check the probability
1334   // is set to a smaller value.
1335   if (null_control != NULL || too_many_traps(reason)) {
1336     // probability is less likely
1337     ok_prob =  PROB_LIKELY_MAG(3);
1338   } else if (!assert_null &&
1339              (ImplicitNullCheckThreshold > 0) &&
1340              method() != NULL &&
1341              (method()->method_data()->trap_count(reason)
1342               >= (uint)ImplicitNullCheckThreshold)) {
1343     ok_prob =  PROB_LIKELY_MAG(3);
1344   }
1345 
1346   if (null_control != NULL) {
1347     IfNode* iff = create_and_map_if(control(), tst, ok_prob, COUNT_UNKNOWN);
1348     Node* null_true = _gvn.transform( new IfFalseNode(iff));
1349     set_control(      _gvn.transform( new IfTrueNode(iff)));
1350 #ifndef PRODUCT
1351     if (null_true == top()) {
1352       explicit_null_checks_elided++;
1353     }
1354 #endif
1355     (*null_control) = null_true;
1356   } else {
1357     BuildCutout unless(this, tst, ok_prob);
1358     // Check for optimizer eliding test at parse time
1359     if (stopped()) {
1360       // Failure not possible; do not bother making uncommon trap.
1361       NOT_PRODUCT(explicit_null_checks_elided++);
1362     } else if (assert_null) {
1363       uncommon_trap(reason,
1364                     Deoptimization::Action_make_not_entrant,
1365                     NULL, "assert_null");
1366     } else {
1367       replace_in_map(value, zerocon(type));
1368       builtin_throw(reason);
1369     }
1370   }
1371 
1372   // Must throw exception, fall-thru not possible?
1373   if (stopped()) {
1374     return top();               // No result
1375   }
1376 
1377   if (assert_null) {
1378     // Cast obj to null on this path.
1379     replace_in_map(value, zerocon(type));
1380     return zerocon(type);
1381   }
1382 
1383   // Cast obj to not-null on this path, if there is no null_control.
1384   // (If there is a null_control, a non-null value may come back to haunt us.)
1385   if (type == T_OBJECT) {
1386     Node* cast = cast_not_null(value, false);
1387     if (null_control == NULL || (*null_control) == top())
1388       replace_in_map(value, cast);
1389     value = cast;
1390   }
1391 
1392   return value;
1393 }
1394 
1395 
1396 //------------------------------cast_not_null----------------------------------
1397 // Cast obj to not-null on this path
1398 Node* GraphKit::cast_not_null(Node* obj, bool do_replace_in_map) {
1399   const Type *t = _gvn.type(obj);
1400   const Type *t_not_null = t->join_speculative(TypePtr::NOTNULL);
1401   // Object is already not-null?
1402   if( t == t_not_null ) return obj;
1403 
1404   Node *cast = new CastPPNode(obj,t_not_null);
1405   cast->init_req(0, control());
1406   cast = _gvn.transform( cast );
1407 
1408   // Scan for instances of 'obj' in the current JVM mapping.
1409   // These instances are known to be not-null after the test.
1410   if (do_replace_in_map)
1411     replace_in_map(obj, cast);
1412 
1413   return cast;                  // Return casted value
1414 }
1415 
1416 // Sometimes in intrinsics, we implicitly know an object is not null
1417 // (there's no actual null check) so we can cast it to not null. In
1418 // the course of optimizations, the input to the cast can become null.
1419 // In that case that data path will die and we need the control path
1420 // to become dead as well to keep the graph consistent. So we have to
1421 // add a check for null for which one branch can't be taken. It uses
1422 // an Opaque4 node that will cause the check to be removed after loop
1423 // opts so the test goes away and the compiled code doesn't execute a
1424 // useless check.
1425 Node* GraphKit::must_be_not_null(Node* value, bool do_replace_in_map) {
1426   Node* chk = _gvn.transform(new CmpPNode(value, null()));
1427   Node *tst = _gvn.transform(new BoolNode(chk, BoolTest::ne));
1428   Node* opaq = _gvn.transform(new Opaque4Node(C, tst, intcon(1)));
1429   IfNode *iff = new IfNode(control(), opaq, PROB_MAX, COUNT_UNKNOWN);
1430   _gvn.set_type(iff, iff->Value(&_gvn));
1431   Node *if_f = _gvn.transform(new IfFalseNode(iff));
1432   Node *frame = _gvn.transform(new ParmNode(C->start(), TypeFunc::FramePtr));
1433   Node *halt = _gvn.transform(new HaltNode(if_f, frame));
1434   C->root()->add_req(halt);
1435   Node *if_t = _gvn.transform(new IfTrueNode(iff));
1436   set_control(if_t);
1437   return cast_not_null(value, do_replace_in_map);
1438 }
1439 
1440 
1441 //--------------------------replace_in_map-------------------------------------
1442 void GraphKit::replace_in_map(Node* old, Node* neww) {
1443   if (old == neww) {
1444     return;
1445   }
1446 
1447   map()->replace_edge(old, neww);
1448 
1449   // Note: This operation potentially replaces any edge
1450   // on the map.  This includes locals, stack, and monitors
1451   // of the current (innermost) JVM state.
1452 
1453   // don't let inconsistent types from profiling escape this
1454   // method
1455 
1456   const Type* told = _gvn.type(old);
1457   const Type* tnew = _gvn.type(neww);
1458 
1459   if (!tnew->higher_equal(told)) {
1460     return;
1461   }
1462 
1463   map()->record_replaced_node(old, neww);
1464 }
1465 
1466 
1467 //=============================================================================
1468 //--------------------------------memory---------------------------------------
1469 Node* GraphKit::memory(uint alias_idx) {
1470   MergeMemNode* mem = merged_memory();
1471   Node* p = mem->memory_at(alias_idx);
1472   _gvn.set_type(p, Type::MEMORY);  // must be mapped
1473   return p;
1474 }
1475 
1476 //-----------------------------reset_memory------------------------------------
1477 Node* GraphKit::reset_memory() {
1478   Node* mem = map()->memory();
1479   // do not use this node for any more parsing!
1480   debug_only( map()->set_memory((Node*)NULL) );
1481   return _gvn.transform( mem );
1482 }
1483 
1484 //------------------------------set_all_memory---------------------------------
1485 void GraphKit::set_all_memory(Node* newmem) {
1486   Node* mergemem = MergeMemNode::make(newmem);
1487   gvn().set_type_bottom(mergemem);
1488   map()->set_memory(mergemem);
1489 }
1490 
1491 //------------------------------set_all_memory_call----------------------------
1492 void GraphKit::set_all_memory_call(Node* call, bool separate_io_proj) {
1493   Node* newmem = _gvn.transform( new ProjNode(call, TypeFunc::Memory, separate_io_proj) );
1494   set_all_memory(newmem);
1495 }
1496 
1497 //=============================================================================
1498 //
1499 // parser factory methods for MemNodes
1500 //
1501 // These are layered on top of the factory methods in LoadNode and StoreNode,
1502 // and integrate with the parser's memory state and _gvn engine.
1503 //
1504 
1505 // factory methods in "int adr_idx"
1506 Node* GraphKit::make_load(Node* ctl, Node* adr, const Type* t, BasicType bt,
1507                           int adr_idx,
1508                           MemNode::MemOrd mo,
1509                           LoadNode::ControlDependency control_dependency,
1510                           bool require_atomic_access,
1511                           bool unaligned,
1512                           bool mismatched) {
1513   assert(adr_idx != Compile::AliasIdxTop, "use other make_load factory" );
1514   const TypePtr* adr_type = NULL; // debug-mode-only argument
1515   debug_only(adr_type = C->get_adr_type(adr_idx));
1516   Node* mem = memory(adr_idx);
1517   Node* ld;
1518   if (require_atomic_access && bt == T_LONG) {
1519     ld = LoadLNode::make_atomic(ctl, mem, adr, adr_type, t, mo, control_dependency, unaligned, mismatched);
1520   } else if (require_atomic_access && bt == T_DOUBLE) {
1521     ld = LoadDNode::make_atomic(ctl, mem, adr, adr_type, t, mo, control_dependency, unaligned, mismatched);
1522   } else {
1523     ld = LoadNode::make(_gvn, ctl, mem, adr, adr_type, t, bt, mo, control_dependency, unaligned, mismatched);
1524   }
1525   ld = _gvn.transform(ld);
1526   if (bt == T_VALUETYPE) {
1527     // Loading a non-flattened value type from memory requires a null check.
1528     ld = ValueTypeNode::make_from_oop(this, ld, t->make_ptr()->is_valuetypeptr()->value_klass(), true /* null check */);
1529   } else if (((bt == T_OBJECT) && C->do_escape_analysis()) || C->eliminate_boxing()) {
1530     // Improve graph before escape analysis and boxing elimination.
1531     record_for_igvn(ld);
1532   }
1533   return ld;
1534 }
1535 
1536 Node* GraphKit::store_to_memory(Node* ctl, Node* adr, Node *val, BasicType bt,
1537                                 int adr_idx,
1538                                 MemNode::MemOrd mo,
1539                                 bool require_atomic_access,
1540                                 bool unaligned,
1541                                 bool mismatched) {
1542   assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
1543   const TypePtr* adr_type = NULL;
1544   debug_only(adr_type = C->get_adr_type(adr_idx));
1545   Node *mem = memory(adr_idx);
1546   Node* st;
1547   if (require_atomic_access && bt == T_LONG) {
1548     st = StoreLNode::make_atomic(ctl, mem, adr, adr_type, val, mo);
1549   } else if (require_atomic_access && bt == T_DOUBLE) {
1550     st = StoreDNode::make_atomic(ctl, mem, adr, adr_type, val, mo);
1551   } else {
1552     st = StoreNode::make(_gvn, ctl, mem, adr, adr_type, val, bt, mo);
1553   }
1554   if (unaligned) {
1555     st->as_Store()->set_unaligned_access();
1556   }
1557   if (mismatched) {
1558     st->as_Store()->set_mismatched_access();
1559   }
1560   st = _gvn.transform(st);
1561   set_memory(st, adr_idx);
1562   // Back-to-back stores can only remove intermediate store with DU info
1563   // so push on worklist for optimizer.
1564   if (mem->req() > MemNode::Address && adr == mem->in(MemNode::Address))
1565     record_for_igvn(st);
1566 
1567   return st;
1568 }
1569 
1570 
1571 void GraphKit::pre_barrier(bool do_load,
1572                            Node* ctl,
1573                            Node* obj,
1574                            Node* adr,
1575                            uint  adr_idx,
1576                            Node* val,
1577                            const TypeOopPtr* val_type,
1578                            Node* pre_val,
1579                            BasicType bt) {
1580 
1581   BarrierSet* bs = Universe::heap()->barrier_set();
1582   set_control(ctl);
1583   switch (bs->kind()) {
1584     case BarrierSet::G1SATBCTLogging:
1585       g1_write_barrier_pre(do_load, obj, adr, adr_idx, val, val_type, pre_val, bt);
1586       break;
1587 
1588     case BarrierSet::CardTableForRS:
1589     case BarrierSet::CardTableExtension:
1590     case BarrierSet::ModRef:
1591       break;
1592 
1593     default      :
1594       ShouldNotReachHere();
1595 
1596   }
1597 }
1598 
1599 bool GraphKit::can_move_pre_barrier() const {
1600   BarrierSet* bs = Universe::heap()->barrier_set();
1601   switch (bs->kind()) {
1602     case BarrierSet::G1SATBCTLogging:
1603       return true; // Can move it if no safepoint
1604 
1605     case BarrierSet::CardTableForRS:
1606     case BarrierSet::CardTableExtension:
1607     case BarrierSet::ModRef:
1608       return true; // There is no pre-barrier
1609 
1610     default      :
1611       ShouldNotReachHere();
1612   }
1613   return false;
1614 }
1615 
1616 void GraphKit::post_barrier(Node* ctl,
1617                             Node* store,
1618                             Node* obj,
1619                             Node* adr,
1620                             uint  adr_idx,
1621                             Node* val,
1622                             BasicType bt,
1623                             bool use_precise) {
1624   BarrierSet* bs = Universe::heap()->barrier_set();
1625   set_control(ctl);
1626   switch (bs->kind()) {
1627     case BarrierSet::G1SATBCTLogging:
1628       g1_write_barrier_post(store, obj, adr, adr_idx, val, bt, use_precise);
1629       break;
1630 
1631     case BarrierSet::CardTableForRS:
1632     case BarrierSet::CardTableExtension:
1633       write_barrier_post(store, obj, adr, adr_idx, val, use_precise);
1634       break;
1635 
1636     case BarrierSet::ModRef:
1637       break;
1638 
1639     default      :
1640       ShouldNotReachHere();
1641 
1642   }
1643 }
1644 
1645 Node* GraphKit::store_oop(Node* ctl,
1646                           Node* obj,
1647                           Node* adr,
1648                           const TypePtr* adr_type,
1649                           Node* val,
1650                           const TypeOopPtr* val_type,
1651                           BasicType bt,
1652                           bool use_precise,
1653                           MemNode::MemOrd mo,
1654                           bool mismatched) {
1655   // Transformation of a value which could be NULL pointer (CastPP #NULL)
1656   // could be delayed during Parse (for example, in adjust_map_after_if()).
1657   // Execute transformation here to avoid barrier generation in such case.
1658   if (_gvn.type(val) == TypePtr::NULL_PTR)
1659     val = _gvn.makecon(TypePtr::NULL_PTR);
1660 
1661   set_control(ctl);
1662   if (stopped()) return top(); // Dead path ?
1663 
1664   assert(bt == T_OBJECT || bt == T_VALUETYPE, "sanity");
1665   assert(val != NULL, "not dead path");
1666   uint adr_idx = C->get_alias_index(adr_type);
1667   assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
1668 
1669   if (val->is_ValueType()) {
1670     // Allocate value type and get oop
1671     val = val->as_ValueType()->allocate(this)->get_oop();
1672   }
1673 
1674   pre_barrier(true /* do_load */,
1675               control(), obj, adr, adr_idx, val, val_type,
1676               NULL /* pre_val */,
1677               bt);
1678 
1679   Node* store = store_to_memory(control(), adr, val, bt, adr_idx, mo, mismatched);
1680   post_barrier(control(), store, obj, adr, adr_idx, val, bt, use_precise);
1681   return store;
1682 }
1683 
1684 // Could be an array or object we don't know at compile time (unsafe ref.)
1685 Node* GraphKit::store_oop_to_unknown(Node* ctl,
1686                              Node* obj,   // containing obj
1687                              Node* adr,  // actual adress to store val at
1688                              const TypePtr* adr_type,
1689                              Node* val,
1690                              BasicType bt,
1691                              MemNode::MemOrd mo,
1692                              bool mismatched) {
1693   Compile::AliasType* at = C->alias_type(adr_type);
1694   const TypeOopPtr* val_type = NULL;
1695   if (adr_type->isa_instptr()) {
1696     if (at->field() != NULL) {
1697       // known field.  This code is a copy of the do_put_xxx logic.
1698       ciField* field = at->field();
1699       if (!field->type()->is_loaded()) {
1700         val_type = TypeInstPtr::BOTTOM;
1701       } else {
1702         val_type = TypeOopPtr::make_from_klass(field->type()->as_klass());
1703       }
1704     }
1705   } else if (adr_type->isa_aryptr()) {
1706     val_type = adr_type->is_aryptr()->elem()->make_oopptr();
1707   }
1708   if (val_type == NULL) {
1709     val_type = TypeInstPtr::BOTTOM;
1710   }
1711   return store_oop(ctl, obj, adr, adr_type, val, val_type, bt, true, mo, mismatched);
1712 }
1713 
1714 
1715 //-------------------------array_element_address-------------------------
1716 Node* GraphKit::array_element_address(Node* ary, Node* idx, BasicType elembt,
1717                                       const TypeInt* sizetype, Node* ctrl) {
1718   uint shift  = exact_log2(type2aelembytes(elembt));
1719   ciKlass* arytype_klass = _gvn.type(ary)->is_aryptr()->klass();
1720   if (arytype_klass->is_value_array_klass()) {
1721     ciValueArrayKlass* vak = arytype_klass->as_value_array_klass();
1722     shift = vak->log2_element_size();
1723   }
1724   uint header = arrayOopDesc::base_offset_in_bytes(elembt);
1725 
1726   // short-circuit a common case (saves lots of confusing waste motion)
1727   jint idx_con = find_int_con(idx, -1);
1728   if (idx_con >= 0) {
1729     intptr_t offset = header + ((intptr_t)idx_con << shift);
1730     return basic_plus_adr(ary, offset);
1731   }
1732 
1733   // must be correct type for alignment purposes
1734   Node* base  = basic_plus_adr(ary, header);
1735   idx = Compile::conv_I2X_index(&_gvn, idx, sizetype, ctrl);
1736   Node* scale = _gvn.transform( new LShiftXNode(idx, intcon(shift)) );
1737   return basic_plus_adr(ary, base, scale);
1738 }
1739 
1740 //-------------------------load_array_element-------------------------
1741 Node* GraphKit::load_array_element(Node* ctl, Node* ary, Node* idx, const TypeAryPtr* arytype) {
1742   const Type* elemtype = arytype->elem();
1743   BasicType elembt = elemtype->array_element_basic_type();
1744   assert(elembt != T_VALUETYPE, "value types are not supported by this method");
1745   Node* adr = array_element_address(ary, idx, elembt, arytype->size());
1746   if (elembt == T_NARROWOOP) {
1747     elembt = T_OBJECT; // To satisfy switch in LoadNode::make()
1748   }
1749   Node* ld = make_load(ctl, adr, elemtype, elembt, arytype, MemNode::unordered);
1750   return ld;
1751 }
1752 
1753 //-------------------------set_arguments_for_java_call-------------------------
1754 // Arguments (pre-popped from the stack) are taken from the JVMS.
1755 void GraphKit::set_arguments_for_java_call(CallJavaNode* call) {
1756   // Add the call arguments:
1757   const TypeTuple* domain = call->tf()->domain_sig();
1758   uint nargs = domain->cnt();
1759   for (uint i = TypeFunc::Parms, idx = TypeFunc::Parms; i < nargs; i++) {
1760     Node* arg = argument(i-TypeFunc::Parms);
1761     if (ValueTypePassFieldsAsArgs) {
1762       if (arg->is_ValueType()) {
1763         ValueTypeNode* vt = arg->as_ValueType();
1764         if (!domain->field_at(i)->is_valuetypeptr()->is__Value()) {
1765           // We don't pass value type arguments by reference but instead
1766           // pass each field of the value type
1767           idx += vt->pass_fields(call, idx, *this);
1768           // If a value type argument is passed as fields, attach the Method* to the call site
1769           // to be able to access the extended signature later via attached_method_before_pc().
1770           // For example, see CompiledMethod::preserve_callee_argument_oops().
1771           call->set_override_symbolic_info(true);
1772         } else {
1773           arg = arg->as_ValueType()->allocate(this)->get_oop();
1774           call->init_req(idx, arg);
1775           idx++;
1776         }
1777       } else {
1778         call->init_req(idx, arg);
1779         idx++;
1780       }
1781     } else {
1782       if (arg->is_ValueType()) {
1783         // Pass value type argument via oop to callee
1784         arg = arg->as_ValueType()->allocate(this)->get_oop();
1785       }
1786       call->init_req(i, arg);
1787     }
1788   }
1789 }
1790 
1791 //---------------------------set_edges_for_java_call---------------------------
1792 // Connect a newly created call into the current JVMS.
1793 // A return value node (if any) is returned from set_edges_for_java_call.
1794 void GraphKit::set_edges_for_java_call(CallJavaNode* call, bool must_throw, bool separate_io_proj) {
1795 
1796   // Add the predefined inputs:
1797   call->init_req( TypeFunc::Control, control() );
1798   call->init_req( TypeFunc::I_O    , i_o() );
1799   call->init_req( TypeFunc::Memory , reset_memory() );
1800   call->init_req( TypeFunc::FramePtr, frameptr() );
1801   call->init_req( TypeFunc::ReturnAdr, top() );
1802 
1803   add_safepoint_edges(call, must_throw);
1804 
1805   Node* xcall = _gvn.transform(call);
1806 
1807   if (xcall == top()) {
1808     set_control(top());
1809     return;
1810   }
1811   assert(xcall == call, "call identity is stable");
1812 
1813   // Re-use the current map to produce the result.
1814 
1815   set_control(_gvn.transform(new ProjNode(call, TypeFunc::Control)));
1816   set_i_o(    _gvn.transform(new ProjNode(call, TypeFunc::I_O    , separate_io_proj)));
1817   set_all_memory_call(xcall, separate_io_proj);
1818 
1819   //return xcall;   // no need, caller already has it
1820 }
1821 
1822 Node* GraphKit::set_results_for_java_call(CallJavaNode* call, bool separate_io_proj) {
1823   if (stopped())  return top();  // maybe the call folded up?
1824 
1825   // Note:  Since any out-of-line call can produce an exception,
1826   // we always insert an I_O projection from the call into the result.
1827 
1828   make_slow_call_ex(call, env()->Throwable_klass(), separate_io_proj);
1829 
1830   if (separate_io_proj) {
1831     // The caller requested separate projections be used by the fall
1832     // through and exceptional paths, so replace the projections for
1833     // the fall through path.
1834     set_i_o(_gvn.transform( new ProjNode(call, TypeFunc::I_O) ));
1835     set_all_memory(_gvn.transform( new ProjNode(call, TypeFunc::Memory) ));
1836   }
1837 
1838   // Capture the return value, if any.
1839   Node* ret;
1840   if (call->method() == NULL ||
1841       call->method()->return_type()->basic_type() == T_VOID) {
1842     ret = top();
1843   } else {
1844     if (!call->tf()->returns_value_type_as_fields()) {
1845       ret = _gvn.transform(new ProjNode(call, TypeFunc::Parms));
1846     } else {
1847       // Return of multiple values (value type fields): we create a
1848       // ValueType node, each field is a projection from the call.
1849       const TypeTuple* range_sig = call->tf()->range_sig();
1850       const Type* t = range_sig->field_at(TypeFunc::Parms);
1851       assert(t->isa_valuetypeptr(), "only value types for multiple return values");
1852       ciValueKlass* vk = t->is_valuetypeptr()->value_klass();
1853       Node* ctl = control();
1854       ret = ValueTypeNode::make_from_multi(_gvn, ctl, merged_memory(), call, vk, TypeFunc::Parms+1, false);
1855       set_control(ctl);
1856     }
1857   }
1858 
1859   return ret;
1860 }
1861 
1862 //--------------------set_predefined_input_for_runtime_call--------------------
1863 // Reading and setting the memory state is way conservative here.
1864 // The real problem is that I am not doing real Type analysis on memory,
1865 // so I cannot distinguish card mark stores from other stores.  Across a GC
1866 // point the Store Barrier and the card mark memory has to agree.  I cannot
1867 // have a card mark store and its barrier split across the GC point from
1868 // either above or below.  Here I get that to happen by reading ALL of memory.
1869 // A better answer would be to separate out card marks from other memory.
1870 // For now, return the input memory state, so that it can be reused
1871 // after the call, if this call has restricted memory effects.
1872 Node* GraphKit::set_predefined_input_for_runtime_call(SafePointNode* call) {
1873   // Set fixed predefined input arguments
1874   Node* memory = reset_memory();
1875   call->init_req( TypeFunc::Control,   control()  );
1876   call->init_req( TypeFunc::I_O,       top()      ); // does no i/o
1877   call->init_req( TypeFunc::Memory,    memory     ); // may gc ptrs
1878   call->init_req( TypeFunc::FramePtr,  frameptr() );
1879   call->init_req( TypeFunc::ReturnAdr, top()      );
1880   return memory;
1881 }
1882 
1883 //-------------------set_predefined_output_for_runtime_call--------------------
1884 // Set control and memory (not i_o) from the call.
1885 // If keep_mem is not NULL, use it for the output state,
1886 // except for the RawPtr output of the call, if hook_mem is TypeRawPtr::BOTTOM.
1887 // If hook_mem is NULL, this call produces no memory effects at all.
1888 // If hook_mem is a Java-visible memory slice (such as arraycopy operands),
1889 // then only that memory slice is taken from the call.
1890 // In the last case, we must put an appropriate memory barrier before
1891 // the call, so as to create the correct anti-dependencies on loads
1892 // preceding the call.
1893 void GraphKit::set_predefined_output_for_runtime_call(Node* call,
1894                                                       Node* keep_mem,
1895                                                       const TypePtr* hook_mem) {
1896   // no i/o
1897   set_control(_gvn.transform( new ProjNode(call,TypeFunc::Control) ));
1898   if (keep_mem) {
1899     // First clone the existing memory state
1900     set_all_memory(keep_mem);
1901     if (hook_mem != NULL) {
1902       // Make memory for the call
1903       Node* mem = _gvn.transform( new ProjNode(call, TypeFunc::Memory) );
1904       // Set the RawPtr memory state only.  This covers all the heap top/GC stuff
1905       // We also use hook_mem to extract specific effects from arraycopy stubs.
1906       set_memory(mem, hook_mem);
1907     }
1908     // ...else the call has NO memory effects.
1909 
1910     // Make sure the call advertises its memory effects precisely.
1911     // This lets us build accurate anti-dependences in gcm.cpp.
1912     assert(C->alias_type(call->adr_type()) == C->alias_type(hook_mem),
1913            "call node must be constructed correctly");
1914   } else {
1915     assert(hook_mem == NULL, "");
1916     // This is not a "slow path" call; all memory comes from the call.
1917     set_all_memory_call(call);
1918   }
1919 }
1920 
1921 
1922 // Replace the call with the current state of the kit.
1923 void GraphKit::replace_call(CallNode* call, Node* result, bool do_replaced_nodes) {
1924   JVMState* ejvms = NULL;
1925   if (has_exceptions()) {
1926     ejvms = transfer_exceptions_into_jvms();
1927   }
1928 
1929   ReplacedNodes replaced_nodes = map()->replaced_nodes();
1930   ReplacedNodes replaced_nodes_exception;
1931   Node* ex_ctl = top();
1932 
1933   SafePointNode* final_state = stop();
1934 
1935   // Find all the needed outputs of this call
1936   CallProjections* callprojs = call->extract_projections(true);
1937 
1938   Node* init_mem = call->in(TypeFunc::Memory);
1939   Node* final_mem = final_state->in(TypeFunc::Memory);
1940   Node* final_ctl = final_state->in(TypeFunc::Control);
1941   Node* final_io = final_state->in(TypeFunc::I_O);
1942 
1943   // Replace all the old call edges with the edges from the inlining result
1944   if (callprojs->fallthrough_catchproj != NULL) {
1945     C->gvn_replace_by(callprojs->fallthrough_catchproj, final_ctl);
1946   }
1947   if (callprojs->fallthrough_memproj != NULL) {
1948     if (final_mem->is_MergeMem()) {
1949       // Parser's exits MergeMem was not transformed but may be optimized
1950       final_mem = _gvn.transform(final_mem);
1951     }
1952     C->gvn_replace_by(callprojs->fallthrough_memproj,   final_mem);
1953   }
1954   if (callprojs->fallthrough_ioproj != NULL) {
1955     C->gvn_replace_by(callprojs->fallthrough_ioproj,    final_io);
1956   }
1957 
1958   // Replace the result with the new result if it exists and is used
1959   if (callprojs->resproj[0] != NULL && result != NULL) {
1960     assert(callprojs->nb_resproj == 1, "unexpected number of results");
1961     C->gvn_replace_by(callprojs->resproj[0], result);
1962   }
1963 
1964   if (ejvms == NULL) {
1965     // No exception edges to simply kill off those paths
1966     if (callprojs->catchall_catchproj != NULL) {
1967       C->gvn_replace_by(callprojs->catchall_catchproj, C->top());
1968     }
1969     if (callprojs->catchall_memproj != NULL) {
1970       C->gvn_replace_by(callprojs->catchall_memproj,   C->top());
1971     }
1972     if (callprojs->catchall_ioproj != NULL) {
1973       C->gvn_replace_by(callprojs->catchall_ioproj,    C->top());
1974     }
1975     // Replace the old exception object with top
1976     if (callprojs->exobj != NULL) {
1977       C->gvn_replace_by(callprojs->exobj, C->top());
1978     }
1979   } else {
1980     GraphKit ekit(ejvms);
1981 
1982     // Load my combined exception state into the kit, with all phis transformed:
1983     SafePointNode* ex_map = ekit.combine_and_pop_all_exception_states();
1984     replaced_nodes_exception = ex_map->replaced_nodes();
1985 
1986     Node* ex_oop = ekit.use_exception_state(ex_map);
1987 
1988     if (callprojs->catchall_catchproj != NULL) {
1989       C->gvn_replace_by(callprojs->catchall_catchproj, ekit.control());
1990       ex_ctl = ekit.control();
1991     }
1992     if (callprojs->catchall_memproj != NULL) {
1993       C->gvn_replace_by(callprojs->catchall_memproj,   ekit.reset_memory());
1994     }
1995     if (callprojs->catchall_ioproj != NULL) {
1996       C->gvn_replace_by(callprojs->catchall_ioproj,    ekit.i_o());
1997     }
1998 
1999     // Replace the old exception object with the newly created one
2000     if (callprojs->exobj != NULL) {
2001       C->gvn_replace_by(callprojs->exobj, ex_oop);
2002     }
2003   }
2004 
2005   // Disconnect the call from the graph
2006   call->disconnect_inputs(NULL, C);
2007   C->gvn_replace_by(call, C->top());
2008 
2009   // Clean up any MergeMems that feed other MergeMems since the
2010   // optimizer doesn't like that.
2011   if (final_mem->is_MergeMem()) {
2012     Node_List wl;
2013     for (SimpleDUIterator i(final_mem); i.has_next(); i.next()) {
2014       Node* m = i.get();
2015       if (m->is_MergeMem() && !wl.contains(m)) {
2016         wl.push(m);
2017       }
2018     }
2019     while (wl.size()  > 0) {
2020       _gvn.transform(wl.pop());
2021     }
2022   }
2023 
2024   if (callprojs->fallthrough_catchproj != NULL && !final_ctl->is_top() && do_replaced_nodes) {
2025     replaced_nodes.apply(C, final_ctl);
2026   }
2027   if (!ex_ctl->is_top() && do_replaced_nodes) {
2028     replaced_nodes_exception.apply(C, ex_ctl);
2029   }
2030 }
2031 
2032 
2033 //------------------------------increment_counter------------------------------
2034 // for statistics: increment a VM counter by 1
2035 
2036 void GraphKit::increment_counter(address counter_addr) {
2037   Node* adr1 = makecon(TypeRawPtr::make(counter_addr));
2038   increment_counter(adr1);
2039 }
2040 
2041 void GraphKit::increment_counter(Node* counter_addr) {
2042   int adr_type = Compile::AliasIdxRaw;
2043   Node* ctrl = control();
2044   Node* cnt  = make_load(ctrl, counter_addr, TypeInt::INT, T_INT, adr_type, MemNode::unordered);
2045   Node* incr = _gvn.transform(new AddINode(cnt, _gvn.intcon(1)));
2046   store_to_memory(ctrl, counter_addr, incr, T_INT, adr_type, MemNode::unordered);
2047 }
2048 
2049 
2050 //------------------------------uncommon_trap----------------------------------
2051 // Bail out to the interpreter in mid-method.  Implemented by calling the
2052 // uncommon_trap blob.  This helper function inserts a runtime call with the
2053 // right debug info.
2054 void GraphKit::uncommon_trap(int trap_request,
2055                              ciKlass* klass, const char* comment,
2056                              bool must_throw,
2057                              bool keep_exact_action) {
2058   if (failing())  stop();
2059   if (stopped())  return; // trap reachable?
2060 
2061   // Note:  If ProfileTraps is true, and if a deopt. actually
2062   // occurs here, the runtime will make sure an MDO exists.  There is
2063   // no need to call method()->ensure_method_data() at this point.
2064 
2065   // Set the stack pointer to the right value for reexecution:
2066   set_sp(reexecute_sp());
2067 
2068 #ifdef ASSERT
2069   if (!must_throw) {
2070     // Make sure the stack has at least enough depth to execute
2071     // the current bytecode.
2072     int inputs, ignored_depth;
2073     if (compute_stack_effects(inputs, ignored_depth)) {
2074       assert(sp() >= inputs, "must have enough JVMS stack to execute %s: sp=%d, inputs=%d",
2075              Bytecodes::name(java_bc()), sp(), inputs);
2076     }
2077   }
2078 #endif
2079 
2080   Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(trap_request);
2081   Deoptimization::DeoptAction action = Deoptimization::trap_request_action(trap_request);
2082 
2083   switch (action) {
2084   case Deoptimization::Action_maybe_recompile:
2085   case Deoptimization::Action_reinterpret:
2086     // Temporary fix for 6529811 to allow virtual calls to be sure they
2087     // get the chance to go from mono->bi->mega
2088     if (!keep_exact_action &&
2089         Deoptimization::trap_request_index(trap_request) < 0 &&
2090         too_many_recompiles(reason)) {
2091       // This BCI is causing too many recompilations.
2092       if (C->log() != NULL) {
2093         C->log()->elem("observe that='trap_action_change' reason='%s' from='%s' to='none'",
2094                 Deoptimization::trap_reason_name(reason),
2095                 Deoptimization::trap_action_name(action));
2096       }
2097       action = Deoptimization::Action_none;
2098       trap_request = Deoptimization::make_trap_request(reason, action);
2099     } else {
2100       C->set_trap_can_recompile(true);
2101     }
2102     break;
2103   case Deoptimization::Action_make_not_entrant:
2104     C->set_trap_can_recompile(true);
2105     break;
2106   case Deoptimization::Action_none:
2107   case Deoptimization::Action_make_not_compilable:
2108     break;
2109   default:
2110 #ifdef ASSERT
2111     fatal("unknown action %d: %s", action, Deoptimization::trap_action_name(action));
2112 #endif
2113     break;
2114   }
2115 
2116   if (TraceOptoParse) {
2117     char buf[100];
2118     tty->print_cr("Uncommon trap %s at bci:%d",
2119                   Deoptimization::format_trap_request(buf, sizeof(buf),
2120                                                       trap_request), bci());
2121   }
2122 
2123   CompileLog* log = C->log();
2124   if (log != NULL) {
2125     int kid = (klass == NULL)? -1: log->identify(klass);
2126     log->begin_elem("uncommon_trap bci='%d'", bci());
2127     char buf[100];
2128     log->print(" %s", Deoptimization::format_trap_request(buf, sizeof(buf),
2129                                                           trap_request));
2130     if (kid >= 0)         log->print(" klass='%d'", kid);
2131     if (comment != NULL)  log->print(" comment='%s'", comment);
2132     log->end_elem();
2133   }
2134 
2135   // Make sure any guarding test views this path as very unlikely
2136   Node *i0 = control()->in(0);
2137   if (i0 != NULL && i0->is_If()) {        // Found a guarding if test?
2138     IfNode *iff = i0->as_If();
2139     float f = iff->_prob;   // Get prob
2140     if (control()->Opcode() == Op_IfTrue) {
2141       if (f > PROB_UNLIKELY_MAG(4))
2142         iff->_prob = PROB_MIN;
2143     } else {
2144       if (f < PROB_LIKELY_MAG(4))
2145         iff->_prob = PROB_MAX;
2146     }
2147   }
2148 
2149   // Clear out dead values from the debug info.
2150   kill_dead_locals();
2151 
2152   // Now insert the uncommon trap subroutine call
2153   address call_addr = SharedRuntime::uncommon_trap_blob()->entry_point();
2154   const TypePtr* no_memory_effects = NULL;
2155   // Pass the index of the class to be loaded
2156   Node* call = make_runtime_call(RC_NO_LEAF | RC_UNCOMMON |
2157                                  (must_throw ? RC_MUST_THROW : 0),
2158                                  OptoRuntime::uncommon_trap_Type(),
2159                                  call_addr, "uncommon_trap", no_memory_effects,
2160                                  intcon(trap_request));
2161   assert(call->as_CallStaticJava()->uncommon_trap_request() == trap_request,
2162          "must extract request correctly from the graph");
2163   assert(trap_request != 0, "zero value reserved by uncommon_trap_request");
2164 
2165   call->set_req(TypeFunc::ReturnAdr, returnadr());
2166   // The debug info is the only real input to this call.
2167 
2168   // Halt-and-catch fire here.  The above call should never return!
2169   HaltNode* halt = new HaltNode(control(), frameptr());
2170   _gvn.set_type_bottom(halt);
2171   root()->add_req(halt);
2172 
2173   stop_and_kill_map();
2174 }
2175 
2176 
2177 //--------------------------just_allocated_object------------------------------
2178 // Report the object that was just allocated.
2179 // It must be the case that there are no intervening safepoints.
2180 // We use this to determine if an object is so "fresh" that
2181 // it does not require card marks.
2182 Node* GraphKit::just_allocated_object(Node* current_control) {
2183   if (C->recent_alloc_ctl() == current_control)
2184     return C->recent_alloc_obj();
2185   return NULL;
2186 }
2187 
2188 
2189 void GraphKit::round_double_arguments(ciMethod* dest_method) {
2190   // (Note:  TypeFunc::make has a cache that makes this fast.)
2191   const TypeFunc* tf    = TypeFunc::make(dest_method);
2192   int             nargs = tf->domain_sig()->cnt() - TypeFunc::Parms;
2193   for (int j = 0; j < nargs; j++) {
2194     const Type *targ = tf->domain_sig()->field_at(j + TypeFunc::Parms);
2195     if( targ->basic_type() == T_DOUBLE ) {
2196       // If any parameters are doubles, they must be rounded before
2197       // the call, dstore_rounding does gvn.transform
2198       Node *arg = argument(j);
2199       arg = dstore_rounding(arg);
2200       set_argument(j, arg);
2201     }
2202   }
2203 }
2204 
2205 /**
2206  * Record profiling data exact_kls for Node n with the type system so
2207  * that it can propagate it (speculation)
2208  *
2209  * @param n          node that the type applies to
2210  * @param exact_kls  type from profiling
2211  * @param maybe_null did profiling see null?
2212  *
2213  * @return           node with improved type
2214  */
2215 Node* GraphKit::record_profile_for_speculation(Node* n, ciKlass* exact_kls, ProfilePtrKind ptr_kind) {
2216   const Type* current_type = _gvn.type(n);
2217   assert(UseTypeSpeculation, "type speculation must be on");
2218 
2219   const TypePtr* speculative = current_type->speculative();
2220 
2221   // Should the klass from the profile be recorded in the speculative type?
2222   if (current_type->would_improve_type(exact_kls, jvms()->depth())) {
2223     const TypeKlassPtr* tklass = TypeKlassPtr::make(exact_kls);
2224     const TypeOopPtr* xtype = tklass->as_instance_type();
2225     assert(xtype->klass_is_exact(), "Should be exact");
2226     // Any reason to believe n is not null (from this profiling or a previous one)?
2227     assert(ptr_kind != ProfileAlwaysNull, "impossible here");
2228     const TypePtr* ptr = (ptr_kind == ProfileMaybeNull && current_type->speculative_maybe_null()) ? TypePtr::BOTTOM : TypePtr::NOTNULL;
2229     // record the new speculative type's depth
2230     speculative = xtype->cast_to_ptr_type(ptr->ptr())->is_ptr();
2231     speculative = speculative->with_inline_depth(jvms()->depth());
2232   } else if (current_type->would_improve_ptr(ptr_kind)) {
2233     // Profiling report that null was never seen so we can change the
2234     // speculative type to non null ptr.
2235     if (ptr_kind == ProfileAlwaysNull) {
2236       speculative = TypePtr::NULL_PTR;
2237     } else {
2238       assert(ptr_kind == ProfileNeverNull, "nothing else is an improvement");
2239       const TypePtr* ptr = TypePtr::NOTNULL;
2240       if (speculative != NULL) {
2241         speculative = speculative->cast_to_ptr_type(ptr->ptr())->is_ptr();
2242       } else {
2243         speculative = ptr;
2244       }
2245     }
2246   }
2247 
2248   if (speculative != current_type->speculative()) {
2249     // Build a type with a speculative type (what we think we know
2250     // about the type but will need a guard when we use it)
2251     const TypeOopPtr* spec_type = TypeOopPtr::make(TypePtr::BotPTR, Type::Offset::bottom, TypeOopPtr::InstanceBot, speculative);
2252     // We're changing the type, we need a new CheckCast node to carry
2253     // the new type. The new type depends on the control: what
2254     // profiling tells us is only valid from here as far as we can
2255     // tell.
2256     Node* cast = new CheckCastPPNode(control(), n, current_type->remove_speculative()->join_speculative(spec_type));
2257     cast = _gvn.transform(cast);
2258     replace_in_map(n, cast);
2259     n = cast;
2260   }
2261 
2262   return n;
2263 }
2264 
2265 /**
2266  * Record profiling data from receiver profiling at an invoke with the
2267  * type system so that it can propagate it (speculation)
2268  *
2269  * @param n  receiver node
2270  *
2271  * @return   node with improved type
2272  */
2273 Node* GraphKit::record_profiled_receiver_for_speculation(Node* n) {
2274   if (!UseTypeSpeculation) {
2275     return n;
2276   }
2277   ciKlass* exact_kls = profile_has_unique_klass();
2278   ProfilePtrKind ptr_kind = ProfileMaybeNull;
2279   if ((java_bc() == Bytecodes::_checkcast ||
2280        java_bc() == Bytecodes::_instanceof ||
2281        java_bc() == Bytecodes::_aastore) &&
2282       method()->method_data()->is_mature()) {
2283     ciProfileData* data = method()->method_data()->bci_to_data(bci());
2284     if (data != NULL) {
2285       if (!data->as_BitData()->null_seen()) {
2286         ptr_kind = ProfileNeverNull;
2287       } else {
2288         assert(data->is_ReceiverTypeData(), "bad profile data type");
2289         ciReceiverTypeData* call = (ciReceiverTypeData*)data->as_ReceiverTypeData();
2290         uint i = 0;
2291         for (; i < call->row_limit(); i++) {
2292           ciKlass* receiver = call->receiver(i);
2293           if (receiver != NULL) {
2294             break;
2295           }
2296         }
2297         ptr_kind = (i == call->row_limit()) ? ProfileAlwaysNull : ProfileMaybeNull;
2298       }
2299     }
2300   }
2301   return record_profile_for_speculation(n, exact_kls, ptr_kind);
2302 }
2303 
2304 /**
2305  * Record profiling data from argument profiling at an invoke with the
2306  * type system so that it can propagate it (speculation)
2307  *
2308  * @param dest_method  target method for the call
2309  * @param bc           what invoke bytecode is this?
2310  */
2311 void GraphKit::record_profiled_arguments_for_speculation(ciMethod* dest_method, Bytecodes::Code bc) {
2312   if (!UseTypeSpeculation) {
2313     return;
2314   }
2315   const TypeFunc* tf    = TypeFunc::make(dest_method);
2316   int             nargs = tf->domain_sig()->cnt() - TypeFunc::Parms;
2317   int skip = Bytecodes::has_receiver(bc) ? 1 : 0;
2318   for (int j = skip, i = 0; j < nargs && i < TypeProfileArgsLimit; j++) {
2319     const Type *targ = tf->domain_sig()->field_at(j + TypeFunc::Parms);
2320     if (targ->isa_oopptr() && !targ->isa_valuetypeptr()) {
2321       ProfilePtrKind ptr_kind = ProfileMaybeNull;
2322       ciKlass* better_type = NULL;
2323       if (method()->argument_profiled_type(bci(), i, better_type, ptr_kind)) {
2324         record_profile_for_speculation(argument(j), better_type, ptr_kind);
2325       }
2326       i++;
2327     }
2328   }
2329 }
2330 
2331 /**
2332  * Record profiling data from parameter profiling at an invoke with
2333  * the type system so that it can propagate it (speculation)
2334  */
2335 void GraphKit::record_profiled_parameters_for_speculation() {
2336   if (!UseTypeSpeculation) {
2337     return;
2338   }
2339   for (int i = 0, j = 0; i < method()->arg_size() ; i++) {
2340     if (_gvn.type(local(i))->isa_oopptr()) {
2341       ProfilePtrKind ptr_kind = ProfileMaybeNull;
2342       ciKlass* better_type = NULL;
2343       if (method()->parameter_profiled_type(j, better_type, ptr_kind)) {
2344         record_profile_for_speculation(local(i), better_type, ptr_kind);
2345       }
2346       j++;
2347     }
2348   }
2349 }
2350 
2351 /**
2352  * Record profiling data from return value profiling at an invoke with
2353  * the type system so that it can propagate it (speculation)
2354  */
2355 void GraphKit::record_profiled_return_for_speculation() {
2356   if (!UseTypeSpeculation) {
2357     return;
2358   }
2359   ProfilePtrKind ptr_kind = ProfileMaybeNull;
2360   ciKlass* better_type = NULL;
2361   if (method()->return_profiled_type(bci(), better_type, ptr_kind)) {
2362     // If profiling reports a single type for the return value,
2363     // feed it to the type system so it can propagate it as a
2364     // speculative type
2365     record_profile_for_speculation(stack(sp()-1), better_type, ptr_kind);
2366   }
2367 }
2368 
2369 void GraphKit::round_double_result(ciMethod* dest_method) {
2370   // A non-strict method may return a double value which has an extended
2371   // exponent, but this must not be visible in a caller which is 'strict'
2372   // If a strict caller invokes a non-strict callee, round a double result
2373 
2374   BasicType result_type = dest_method->return_type()->basic_type();
2375   assert( method() != NULL, "must have caller context");
2376   if( result_type == T_DOUBLE && method()->is_strict() && !dest_method->is_strict() ) {
2377     // Destination method's return value is on top of stack
2378     // dstore_rounding() does gvn.transform
2379     Node *result = pop_pair();
2380     result = dstore_rounding(result);
2381     push_pair(result);
2382   }
2383 }
2384 
2385 // rounding for strict float precision conformance
2386 Node* GraphKit::precision_rounding(Node* n) {
2387   return UseStrictFP && _method->flags().is_strict()
2388     && UseSSE == 0 && Matcher::strict_fp_requires_explicit_rounding
2389     ? _gvn.transform( new RoundFloatNode(0, n) )
2390     : n;
2391 }
2392 
2393 // rounding for strict double precision conformance
2394 Node* GraphKit::dprecision_rounding(Node *n) {
2395   return UseStrictFP && _method->flags().is_strict()
2396     && UseSSE <= 1 && Matcher::strict_fp_requires_explicit_rounding
2397     ? _gvn.transform( new RoundDoubleNode(0, n) )
2398     : n;
2399 }
2400 
2401 // rounding for non-strict double stores
2402 Node* GraphKit::dstore_rounding(Node* n) {
2403   return Matcher::strict_fp_requires_explicit_rounding
2404     && UseSSE <= 1
2405     ? _gvn.transform( new RoundDoubleNode(0, n) )
2406     : n;
2407 }
2408 
2409 //=============================================================================
2410 // Generate a fast path/slow path idiom.  Graph looks like:
2411 // [foo] indicates that 'foo' is a parameter
2412 //
2413 //              [in]     NULL
2414 //                 \    /
2415 //                  CmpP
2416 //                  Bool ne
2417 //                   If
2418 //                  /  \
2419 //              True    False-<2>
2420 //              / |
2421 //             /  cast_not_null
2422 //           Load  |    |   ^
2423 //        [fast_test]   |   |
2424 // gvn to   opt_test    |   |
2425 //          /    \      |  <1>
2426 //      True     False  |
2427 //        |         \\  |
2428 //   [slow_call]     \[fast_result]
2429 //    Ctl   Val       \      \
2430 //     |               \      \
2431 //    Catch       <1>   \      \
2432 //   /    \        ^     \      \
2433 //  Ex    No_Ex    |      \      \
2434 //  |       \   \  |       \ <2>  \
2435 //  ...      \  [slow_res] |  |    \   [null_result]
2436 //            \         \--+--+---  |  |
2437 //             \           | /    \ | /
2438 //              --------Region     Phi
2439 //
2440 //=============================================================================
2441 // Code is structured as a series of driver functions all called 'do_XXX' that
2442 // call a set of helper functions.  Helper functions first, then drivers.
2443 
2444 //------------------------------null_check_oop---------------------------------
2445 // Null check oop.  Set null-path control into Region in slot 3.
2446 // Make a cast-not-nullness use the other not-null control.  Return cast.
2447 Node* GraphKit::null_check_oop(Node* value, Node* *null_control,
2448                                bool never_see_null,
2449                                bool safe_for_replace,
2450                                bool speculative) {
2451   // Initial NULL check taken path
2452   (*null_control) = top();
2453   Node* cast = null_check_common(value, T_OBJECT, false, null_control, speculative);
2454 
2455   // Generate uncommon_trap:
2456   if (never_see_null && (*null_control) != top()) {
2457     // If we see an unexpected null at a check-cast we record it and force a
2458     // recompile; the offending check-cast will be compiled to handle NULLs.
2459     // If we see more than one offending BCI, then all checkcasts in the
2460     // method will be compiled to handle NULLs.
2461     PreserveJVMState pjvms(this);
2462     set_control(*null_control);
2463     replace_in_map(value, null());
2464     Deoptimization::DeoptReason reason = Deoptimization::reason_null_check(speculative);
2465     uncommon_trap(reason,
2466                   Deoptimization::Action_make_not_entrant);
2467     (*null_control) = top();    // NULL path is dead
2468   }
2469   if ((*null_control) == top() && safe_for_replace) {
2470     replace_in_map(value, cast);
2471   }
2472 
2473   // Cast away null-ness on the result
2474   return cast;
2475 }
2476 
2477 //------------------------------opt_iff----------------------------------------
2478 // Optimize the fast-check IfNode.  Set the fast-path region slot 2.
2479 // Return slow-path control.
2480 Node* GraphKit::opt_iff(Node* region, Node* iff) {
2481   IfNode *opt_iff = _gvn.transform(iff)->as_If();
2482 
2483   // Fast path taken; set region slot 2
2484   Node *fast_taken = _gvn.transform( new IfFalseNode(opt_iff) );
2485   region->init_req(2,fast_taken); // Capture fast-control
2486 
2487   // Fast path not-taken, i.e. slow path
2488   Node *slow_taken = _gvn.transform( new IfTrueNode(opt_iff) );
2489   return slow_taken;
2490 }
2491 
2492 //-----------------------------make_runtime_call-------------------------------
2493 Node* GraphKit::make_runtime_call(int flags,
2494                                   const TypeFunc* call_type, address call_addr,
2495                                   const char* call_name,
2496                                   const TypePtr* adr_type,
2497                                   // The following parms are all optional.
2498                                   // The first NULL ends the list.
2499                                   Node* parm0, Node* parm1,
2500                                   Node* parm2, Node* parm3,
2501                                   Node* parm4, Node* parm5,
2502                                   Node* parm6, Node* parm7) {
2503   // Slow-path call
2504   bool is_leaf = !(flags & RC_NO_LEAF);
2505   bool has_io  = (!is_leaf && !(flags & RC_NO_IO));
2506   if (call_name == NULL) {
2507     assert(!is_leaf, "must supply name for leaf");
2508     call_name = OptoRuntime::stub_name(call_addr);
2509   }
2510   CallNode* call;
2511   if (!is_leaf) {
2512     call = new CallStaticJavaNode(call_type, call_addr, call_name,
2513                                            bci(), adr_type);
2514   } else if (flags & RC_NO_FP) {
2515     call = new CallLeafNoFPNode(call_type, call_addr, call_name, adr_type);
2516   } else {
2517     call = new CallLeafNode(call_type, call_addr, call_name, adr_type);
2518   }
2519 
2520   // The following is similar to set_edges_for_java_call,
2521   // except that the memory effects of the call are restricted to AliasIdxRaw.
2522 
2523   // Slow path call has no side-effects, uses few values
2524   bool wide_in  = !(flags & RC_NARROW_MEM);
2525   bool wide_out = (C->get_alias_index(adr_type) == Compile::AliasIdxBot);
2526 
2527   Node* prev_mem = NULL;
2528   if (wide_in) {
2529     prev_mem = set_predefined_input_for_runtime_call(call);
2530   } else {
2531     assert(!wide_out, "narrow in => narrow out");
2532     Node* narrow_mem = memory(adr_type);
2533     prev_mem = reset_memory();
2534     map()->set_memory(narrow_mem);
2535     set_predefined_input_for_runtime_call(call);
2536   }
2537 
2538   // Hook each parm in order.  Stop looking at the first NULL.
2539   if (parm0 != NULL) { call->init_req(TypeFunc::Parms+0, parm0);
2540   if (parm1 != NULL) { call->init_req(TypeFunc::Parms+1, parm1);
2541   if (parm2 != NULL) { call->init_req(TypeFunc::Parms+2, parm2);
2542   if (parm3 != NULL) { call->init_req(TypeFunc::Parms+3, parm3);
2543   if (parm4 != NULL) { call->init_req(TypeFunc::Parms+4, parm4);
2544   if (parm5 != NULL) { call->init_req(TypeFunc::Parms+5, parm5);
2545   if (parm6 != NULL) { call->init_req(TypeFunc::Parms+6, parm6);
2546   if (parm7 != NULL) { call->init_req(TypeFunc::Parms+7, parm7);
2547     /* close each nested if ===> */  } } } } } } } }
2548   assert(call->in(call->req()-1) != NULL, "must initialize all parms");
2549 
2550   if (!is_leaf) {
2551     // Non-leaves can block and take safepoints:
2552     add_safepoint_edges(call, ((flags & RC_MUST_THROW) != 0));
2553   }
2554   // Non-leaves can throw exceptions:
2555   if (has_io) {
2556     call->set_req(TypeFunc::I_O, i_o());
2557   }
2558 
2559   if (flags & RC_UNCOMMON) {
2560     // Set the count to a tiny probability.  Cf. Estimate_Block_Frequency.
2561     // (An "if" probability corresponds roughly to an unconditional count.
2562     // Sort of.)
2563     call->set_cnt(PROB_UNLIKELY_MAG(4));
2564   }
2565 
2566   Node* c = _gvn.transform(call);
2567   assert(c == call, "cannot disappear");
2568 
2569   if (wide_out) {
2570     // Slow path call has full side-effects.
2571     set_predefined_output_for_runtime_call(call);
2572   } else {
2573     // Slow path call has few side-effects, and/or sets few values.
2574     set_predefined_output_for_runtime_call(call, prev_mem, adr_type);
2575   }
2576 
2577   if (has_io) {
2578     set_i_o(_gvn.transform(new ProjNode(call, TypeFunc::I_O)));
2579   }
2580   return call;
2581 
2582 }
2583 
2584 //------------------------------merge_memory-----------------------------------
2585 // Merge memory from one path into the current memory state.
2586 void GraphKit::merge_memory(Node* new_mem, Node* region, int new_path) {
2587   for (MergeMemStream mms(merged_memory(), new_mem->as_MergeMem()); mms.next_non_empty2(); ) {
2588     Node* old_slice = mms.force_memory();
2589     Node* new_slice = mms.memory2();
2590     if (old_slice != new_slice) {
2591       PhiNode* phi;
2592       if (old_slice->is_Phi() && old_slice->as_Phi()->region() == region) {
2593         if (mms.is_empty()) {
2594           // clone base memory Phi's inputs for this memory slice
2595           assert(old_slice == mms.base_memory(), "sanity");
2596           phi = PhiNode::make(region, NULL, Type::MEMORY, mms.adr_type(C));
2597           _gvn.set_type(phi, Type::MEMORY);
2598           for (uint i = 1; i < phi->req(); i++) {
2599             phi->init_req(i, old_slice->in(i));
2600           }
2601         } else {
2602           phi = old_slice->as_Phi(); // Phi was generated already
2603         }
2604       } else {
2605         phi = PhiNode::make(region, old_slice, Type::MEMORY, mms.adr_type(C));
2606         _gvn.set_type(phi, Type::MEMORY);
2607       }
2608       phi->set_req(new_path, new_slice);
2609       mms.set_memory(phi);
2610     }
2611   }
2612 }
2613 
2614 //------------------------------make_slow_call_ex------------------------------
2615 // Make the exception handler hookups for the slow call
2616 void GraphKit::make_slow_call_ex(Node* call, ciInstanceKlass* ex_klass, bool separate_io_proj, bool deoptimize) {
2617   if (stopped())  return;
2618 
2619   // Make a catch node with just two handlers:  fall-through and catch-all
2620   Node* i_o  = _gvn.transform( new ProjNode(call, TypeFunc::I_O, separate_io_proj) );
2621   Node* catc = _gvn.transform( new CatchNode(control(), i_o, 2) );
2622   Node* norm = _gvn.transform( new CatchProjNode(catc, CatchProjNode::fall_through_index, CatchProjNode::no_handler_bci) );
2623   Node* excp = _gvn.transform( new CatchProjNode(catc, CatchProjNode::catch_all_index,    CatchProjNode::no_handler_bci) );
2624 
2625   { PreserveJVMState pjvms(this);
2626     set_control(excp);
2627     set_i_o(i_o);
2628 
2629     if (excp != top()) {
2630       if (deoptimize) {
2631         // Deoptimize if an exception is caught. Don't construct exception state in this case.
2632         uncommon_trap(Deoptimization::Reason_unhandled,
2633                       Deoptimization::Action_none);
2634       } else {
2635         // Create an exception state also.
2636         // Use an exact type if the caller has specified a specific exception.
2637         const Type* ex_type = TypeOopPtr::make_from_klass_unique(ex_klass)->cast_to_ptr_type(TypePtr::NotNull);
2638         Node*       ex_oop  = new CreateExNode(ex_type, control(), i_o);
2639         add_exception_state(make_exception_state(_gvn.transform(ex_oop)));
2640       }
2641     }
2642   }
2643 
2644   // Get the no-exception control from the CatchNode.
2645   set_control(norm);
2646 }
2647 
2648 static IfNode* gen_subtype_check_compare(Node* ctrl, Node* in1, Node* in2, BoolTest::mask test, float p, PhaseGVN* gvn, BasicType bt) {
2649   Node* cmp = NULL;
2650   switch(bt) {
2651   case T_INT: cmp = new CmpINode(in1, in2); break;
2652   case T_ADDRESS: cmp = new CmpPNode(in1, in2); break;
2653   default: fatal("unexpected comparison type %s", type2name(bt));
2654   }
2655   gvn->transform(cmp);
2656   Node* bol = gvn->transform(new BoolNode(cmp, test));
2657   IfNode* iff = new IfNode(ctrl, bol, p, COUNT_UNKNOWN);
2658   gvn->transform(iff);
2659   if (!bol->is_Con()) gvn->record_for_igvn(iff);
2660   return iff;
2661 }
2662 
2663 
2664 //-------------------------------gen_subtype_check-----------------------------
2665 // Generate a subtyping check.  Takes as input the subtype and supertype.
2666 // Returns 2 values: sets the default control() to the true path and returns
2667 // the false path.  Only reads invariant memory; sets no (visible) memory.
2668 // The PartialSubtypeCheckNode sets the hidden 1-word cache in the encoding
2669 // but that's not exposed to the optimizer.  This call also doesn't take in an
2670 // Object; if you wish to check an Object you need to load the Object's class
2671 // prior to coming here.
2672 Node* Phase::gen_subtype_check(Node* subklass, Node* superklass, Node** ctrl, MergeMemNode* mem, PhaseGVN* gvn) {
2673   Compile* C = gvn->C;
2674 
2675   if ((*ctrl)->is_top()) {
2676     return C->top();
2677   }
2678 
2679   // Fast check for identical types, perhaps identical constants.
2680   // The types can even be identical non-constants, in cases
2681   // involving Array.newInstance, Object.clone, etc.
2682   if (subklass == superklass)
2683     return C->top();             // false path is dead; no test needed.
2684 
2685   if (gvn->type(superklass)->singleton()) {
2686     ciKlass* superk = gvn->type(superklass)->is_klassptr()->klass();
2687     ciKlass* subk   = gvn->type(subklass)->is_klassptr()->klass();
2688 
2689     // In the common case of an exact superklass, try to fold up the
2690     // test before generating code.  You may ask, why not just generate
2691     // the code and then let it fold up?  The answer is that the generated
2692     // code will necessarily include null checks, which do not always
2693     // completely fold away.  If they are also needless, then they turn
2694     // into a performance loss.  Example:
2695     //    Foo[] fa = blah(); Foo x = fa[0]; fa[1] = x;
2696     // Here, the type of 'fa' is often exact, so the store check
2697     // of fa[1]=x will fold up, without testing the nullness of x.
2698     switch (C->static_subtype_check(superk, subk)) {
2699     case Compile::SSC_always_false:
2700       {
2701         Node* always_fail = *ctrl;
2702         *ctrl = gvn->C->top();
2703         return always_fail;
2704       }
2705     case Compile::SSC_always_true:
2706       return C->top();
2707     case Compile::SSC_easy_test:
2708       {
2709         // Just do a direct pointer compare and be done.
2710         IfNode* iff = gen_subtype_check_compare(*ctrl, subklass, superklass, BoolTest::eq, PROB_STATIC_FREQUENT, gvn, T_ADDRESS);
2711         *ctrl = gvn->transform(new IfTrueNode(iff));
2712         return gvn->transform(new IfFalseNode(iff));
2713       }
2714     case Compile::SSC_full_test:
2715       break;
2716     default:
2717       ShouldNotReachHere();
2718     }
2719   }
2720 
2721   // %%% Possible further optimization:  Even if the superklass is not exact,
2722   // if the subklass is the unique subtype of the superklass, the check
2723   // will always succeed.  We could leave a dependency behind to ensure this.
2724 
2725   // First load the super-klass's check-offset
2726   Node *p1 = gvn->transform(new AddPNode(superklass, superklass, gvn->MakeConX(in_bytes(Klass::super_check_offset_offset()))));
2727   Node* m = mem->memory_at(C->get_alias_index(gvn->type(p1)->is_ptr()));
2728   Node *chk_off = gvn->transform(new LoadINode(NULL, m, p1, gvn->type(p1)->is_ptr(), TypeInt::INT, MemNode::unordered));
2729   int cacheoff_con = in_bytes(Klass::secondary_super_cache_offset());
2730   bool might_be_cache = (gvn->find_int_con(chk_off, cacheoff_con) == cacheoff_con);
2731 
2732   // Load from the sub-klass's super-class display list, or a 1-word cache of
2733   // the secondary superclass list, or a failing value with a sentinel offset
2734   // if the super-klass is an interface or exceptionally deep in the Java
2735   // hierarchy and we have to scan the secondary superclass list the hard way.
2736   // Worst-case type is a little odd: NULL is allowed as a result (usually
2737   // klass loads can never produce a NULL).
2738   Node *chk_off_X = chk_off;
2739 #ifdef _LP64
2740   chk_off_X = gvn->transform(new ConvI2LNode(chk_off_X));
2741 #endif
2742   Node *p2 = gvn->transform(new AddPNode(subklass,subklass,chk_off_X));
2743   // For some types like interfaces the following loadKlass is from a 1-word
2744   // cache which is mutable so can't use immutable memory.  Other
2745   // types load from the super-class display table which is immutable.
2746   m = mem->memory_at(C->get_alias_index(gvn->type(p2)->is_ptr()));
2747   Node *kmem = might_be_cache ? m : C->immutable_memory();
2748   Node *nkls = gvn->transform(LoadKlassNode::make(*gvn, NULL, kmem, p2, gvn->type(p2)->is_ptr(), TypeKlassPtr::BOTTOM));
2749 
2750   // Compile speed common case: ARE a subtype and we canNOT fail
2751   if( superklass == nkls )
2752     return C->top();             // false path is dead; no test needed.
2753 
2754   // See if we get an immediate positive hit.  Happens roughly 83% of the
2755   // time.  Test to see if the value loaded just previously from the subklass
2756   // is exactly the superklass.
2757   IfNode *iff1 = gen_subtype_check_compare(*ctrl, superklass, nkls, BoolTest::eq, PROB_LIKELY(0.83f), gvn, T_ADDRESS);
2758   Node *iftrue1 = gvn->transform( new IfTrueNode (iff1));
2759   *ctrl = gvn->transform(new IfFalseNode(iff1));
2760 
2761   // Compile speed common case: Check for being deterministic right now.  If
2762   // chk_off is a constant and not equal to cacheoff then we are NOT a
2763   // subklass.  In this case we need exactly the 1 test above and we can
2764   // return those results immediately.
2765   if (!might_be_cache) {
2766     Node* not_subtype_ctrl = *ctrl;
2767     *ctrl = iftrue1; // We need exactly the 1 test above
2768     return not_subtype_ctrl;
2769   }
2770 
2771   // Gather the various success & failures here
2772   RegionNode *r_ok_subtype = new RegionNode(4);
2773   gvn->record_for_igvn(r_ok_subtype);
2774   RegionNode *r_not_subtype = new RegionNode(3);
2775   gvn->record_for_igvn(r_not_subtype);
2776 
2777   r_ok_subtype->init_req(1, iftrue1);
2778 
2779   // Check for immediate negative hit.  Happens roughly 11% of the time (which
2780   // is roughly 63% of the remaining cases).  Test to see if the loaded
2781   // check-offset points into the subklass display list or the 1-element
2782   // cache.  If it points to the display (and NOT the cache) and the display
2783   // missed then it's not a subtype.
2784   Node *cacheoff = gvn->intcon(cacheoff_con);
2785   IfNode *iff2 = gen_subtype_check_compare(*ctrl, chk_off, cacheoff, BoolTest::ne, PROB_LIKELY(0.63f), gvn, T_INT);
2786   r_not_subtype->init_req(1, gvn->transform(new IfTrueNode (iff2)));
2787   *ctrl = gvn->transform(new IfFalseNode(iff2));
2788 
2789   // Check for self.  Very rare to get here, but it is taken 1/3 the time.
2790   // No performance impact (too rare) but allows sharing of secondary arrays
2791   // which has some footprint reduction.
2792   IfNode *iff3 = gen_subtype_check_compare(*ctrl, subklass, superklass, BoolTest::eq, PROB_LIKELY(0.36f), gvn, T_ADDRESS);
2793   r_ok_subtype->init_req(2, gvn->transform(new IfTrueNode(iff3)));
2794   *ctrl = gvn->transform(new IfFalseNode(iff3));
2795 
2796   // -- Roads not taken here: --
2797   // We could also have chosen to perform the self-check at the beginning
2798   // of this code sequence, as the assembler does.  This would not pay off
2799   // the same way, since the optimizer, unlike the assembler, can perform
2800   // static type analysis to fold away many successful self-checks.
2801   // Non-foldable self checks work better here in second position, because
2802   // the initial primary superclass check subsumes a self-check for most
2803   // types.  An exception would be a secondary type like array-of-interface,
2804   // which does not appear in its own primary supertype display.
2805   // Finally, we could have chosen to move the self-check into the
2806   // PartialSubtypeCheckNode, and from there out-of-line in a platform
2807   // dependent manner.  But it is worthwhile to have the check here,
2808   // where it can be perhaps be optimized.  The cost in code space is
2809   // small (register compare, branch).
2810 
2811   // Now do a linear scan of the secondary super-klass array.  Again, no real
2812   // performance impact (too rare) but it's gotta be done.
2813   // Since the code is rarely used, there is no penalty for moving it
2814   // out of line, and it can only improve I-cache density.
2815   // The decision to inline or out-of-line this final check is platform
2816   // dependent, and is found in the AD file definition of PartialSubtypeCheck.
2817   Node* psc = gvn->transform(
2818     new PartialSubtypeCheckNode(*ctrl, subklass, superklass));
2819 
2820   IfNode *iff4 = gen_subtype_check_compare(*ctrl, psc, gvn->zerocon(T_OBJECT), BoolTest::ne, PROB_FAIR, gvn, T_ADDRESS);
2821   r_not_subtype->init_req(2, gvn->transform(new IfTrueNode (iff4)));
2822   r_ok_subtype ->init_req(3, gvn->transform(new IfFalseNode(iff4)));
2823 
2824   // Return false path; set default control to true path.
2825   *ctrl = gvn->transform(r_ok_subtype);
2826   return gvn->transform(r_not_subtype);
2827 }
2828 
2829 // Profile-driven exact type check:
2830 Node* GraphKit::type_check_receiver(Node* receiver, ciKlass* klass,
2831                                     float prob,
2832                                     Node* *casted_receiver) {
2833   const TypeKlassPtr* tklass = TypeKlassPtr::make(klass);
2834   Node* recv_klass = load_object_klass(receiver);
2835   Node* fail = type_check(recv_klass, tklass, prob);
2836   const TypeOopPtr* recv_xtype = tklass->as_instance_type();
2837   assert(recv_xtype->klass_is_exact(), "");
2838 
2839   // Subsume downstream occurrences of receiver with a cast to
2840   // recv_xtype, since now we know what the type will be.
2841   Node* cast = new CheckCastPPNode(control(), receiver, recv_xtype);
2842   (*casted_receiver) = _gvn.transform(cast);
2843   // (User must make the replace_in_map call.)
2844 
2845   return fail;
2846 }
2847 
2848 Node* GraphKit::type_check(Node* recv_klass, const TypeKlassPtr* tklass,
2849                            float prob) {
2850   //const TypeKlassPtr* tklass = TypeKlassPtr::make(klass);
2851   Node* want_klass = makecon(tklass);
2852   Node* cmp = _gvn.transform( new CmpPNode(recv_klass, want_klass));
2853   Node* bol = _gvn.transform( new BoolNode(cmp, BoolTest::eq) );
2854   IfNode* iff = create_and_xform_if(control(), bol, prob, COUNT_UNKNOWN);
2855   set_control(  _gvn.transform( new IfTrueNode (iff)));
2856   Node* fail = _gvn.transform( new IfFalseNode(iff));
2857   return fail;
2858 }
2859 
2860 
2861 //------------------------------seems_never_null-------------------------------
2862 // Use null_seen information if it is available from the profile.
2863 // If we see an unexpected null at a type check we record it and force a
2864 // recompile; the offending check will be recompiled to handle NULLs.
2865 // If we see several offending BCIs, then all checks in the
2866 // method will be recompiled.
2867 bool GraphKit::seems_never_null(Node* obj, ciProfileData* data, bool& speculating) {
2868   speculating = !_gvn.type(obj)->speculative_maybe_null();
2869   Deoptimization::DeoptReason reason = Deoptimization::reason_null_check(speculating);
2870   if (UncommonNullCast               // Cutout for this technique
2871       && obj != null()               // And not the -Xcomp stupid case?
2872       && !too_many_traps(reason)
2873       ) {
2874     if (speculating) {
2875       return true;
2876     }
2877     if (data == NULL)
2878       // Edge case:  no mature data.  Be optimistic here.
2879       return true;
2880     // If the profile has not seen a null, assume it won't happen.
2881     assert(java_bc() == Bytecodes::_checkcast ||
2882            java_bc() == Bytecodes::_instanceof ||
2883            java_bc() == Bytecodes::_aastore, "MDO must collect null_seen bit here");
2884     return !data->as_BitData()->null_seen();
2885   }
2886   speculating = false;
2887   return false;
2888 }
2889 
2890 //------------------------maybe_cast_profiled_receiver-------------------------
2891 // If the profile has seen exactly one type, narrow to exactly that type.
2892 // Subsequent type checks will always fold up.
2893 Node* GraphKit::maybe_cast_profiled_receiver(Node* not_null_obj,
2894                                              ciKlass* require_klass,
2895                                              ciKlass* spec_klass,
2896                                              bool safe_for_replace) {
2897   if (!UseTypeProfile || !TypeProfileCasts) return NULL;
2898 
2899   Deoptimization::DeoptReason reason = Deoptimization::reason_class_check(spec_klass != NULL);
2900 
2901   // Make sure we haven't already deoptimized from this tactic.
2902   if (too_many_traps(reason) || too_many_recompiles(reason))
2903     return NULL;
2904 
2905   // (No, this isn't a call, but it's enough like a virtual call
2906   // to use the same ciMethod accessor to get the profile info...)
2907   // If we have a speculative type use it instead of profiling (which
2908   // may not help us)
2909   ciKlass* exact_kls = spec_klass == NULL ? profile_has_unique_klass() : spec_klass;
2910   if (exact_kls != NULL) {// no cast failures here
2911     if (require_klass == NULL ||
2912         C->static_subtype_check(require_klass, exact_kls) == Compile::SSC_always_true) {
2913       // If we narrow the type to match what the type profile sees or
2914       // the speculative type, we can then remove the rest of the
2915       // cast.
2916       // This is a win, even if the exact_kls is very specific,
2917       // because downstream operations, such as method calls,
2918       // will often benefit from the sharper type.
2919       Node* exact_obj = not_null_obj; // will get updated in place...
2920       Node* slow_ctl  = type_check_receiver(exact_obj, exact_kls, 1.0,
2921                                             &exact_obj);
2922       { PreserveJVMState pjvms(this);
2923         set_control(slow_ctl);
2924         uncommon_trap_exact(reason, Deoptimization::Action_maybe_recompile);
2925       }
2926       if (safe_for_replace) {
2927         replace_in_map(not_null_obj, exact_obj);
2928       }
2929       return exact_obj;
2930     }
2931     // assert(ssc == Compile::SSC_always_true)... except maybe the profile lied to us.
2932   }
2933 
2934   return NULL;
2935 }
2936 
2937 /**
2938  * Cast obj to type and emit guard unless we had too many traps here
2939  * already
2940  *
2941  * @param obj       node being casted
2942  * @param type      type to cast the node to
2943  * @param not_null  true if we know node cannot be null
2944  */
2945 Node* GraphKit::maybe_cast_profiled_obj(Node* obj,
2946                                         ciKlass* type,
2947                                         bool not_null) {
2948   if (stopped()) {
2949     return obj;
2950   }
2951 
2952   // type == NULL if profiling tells us this object is always null
2953   if (type != NULL) {
2954     Deoptimization::DeoptReason class_reason = Deoptimization::Reason_speculate_class_check;
2955     Deoptimization::DeoptReason null_reason = Deoptimization::Reason_speculate_null_check;
2956 
2957     if (!too_many_traps(null_reason) && !too_many_recompiles(null_reason) &&
2958         !too_many_traps(class_reason) &&
2959         !too_many_recompiles(class_reason)) {
2960       Node* not_null_obj = NULL;
2961       // not_null is true if we know the object is not null and
2962       // there's no need for a null check
2963       if (!not_null) {
2964         Node* null_ctl = top();
2965         not_null_obj = null_check_oop(obj, &null_ctl, true, true, true);
2966         assert(null_ctl->is_top(), "no null control here");
2967       } else {
2968         not_null_obj = obj;
2969       }
2970 
2971       Node* exact_obj = not_null_obj;
2972       ciKlass* exact_kls = type;
2973       Node* slow_ctl  = type_check_receiver(exact_obj, exact_kls, 1.0,
2974                                             &exact_obj);
2975       {
2976         PreserveJVMState pjvms(this);
2977         set_control(slow_ctl);
2978         uncommon_trap_exact(class_reason, Deoptimization::Action_maybe_recompile);
2979       }
2980       replace_in_map(not_null_obj, exact_obj);
2981       obj = exact_obj;
2982     }
2983   } else {
2984     if (!too_many_traps(Deoptimization::Reason_null_assert) &&
2985         !too_many_recompiles(Deoptimization::Reason_null_assert)) {
2986       Node* exact_obj = null_assert(obj);
2987       replace_in_map(obj, exact_obj);
2988       obj = exact_obj;
2989     }
2990   }
2991   return obj;
2992 }
2993 
2994 //-------------------------------gen_instanceof--------------------------------
2995 // Generate an instance-of idiom.  Used by both the instance-of bytecode
2996 // and the reflective instance-of call.
2997 Node* GraphKit::gen_instanceof(Node* obj, Node* superklass, bool safe_for_replace) {
2998   kill_dead_locals();           // Benefit all the uncommon traps
2999   assert( !stopped(), "dead parse path should be checked in callers" );
3000   assert(!TypePtr::NULL_PTR->higher_equal(_gvn.type(superklass)->is_klassptr()),
3001          "must check for not-null not-dead klass in callers");
3002 
3003   // Make the merge point
3004   enum { _obj_path = 1, _fail_path, _null_path, PATH_LIMIT };
3005   RegionNode* region = new RegionNode(PATH_LIMIT);
3006   Node*       phi    = new PhiNode(region, TypeInt::BOOL);
3007   C->set_has_split_ifs(true); // Has chance for split-if optimization
3008 
3009   ciProfileData* data = NULL;
3010   if (java_bc() == Bytecodes::_instanceof) {  // Only for the bytecode
3011     data = method()->method_data()->bci_to_data(bci());
3012   }
3013   bool speculative_not_null = false;
3014   bool never_see_null = (ProfileDynamicTypes  // aggressive use of profile
3015                          && seems_never_null(obj, data, speculative_not_null));
3016 
3017   // Null check; get casted pointer; set region slot 3
3018   Node* null_ctl = top();
3019   Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null, safe_for_replace, speculative_not_null);
3020 
3021   // If not_null_obj is dead, only null-path is taken
3022   if (stopped()) {              // Doing instance-of on a NULL?
3023     set_control(null_ctl);
3024     return intcon(0);
3025   }
3026   region->init_req(_null_path, null_ctl);
3027   phi   ->init_req(_null_path, intcon(0)); // Set null path value
3028   if (null_ctl == top()) {
3029     // Do this eagerly, so that pattern matches like is_diamond_phi
3030     // will work even during parsing.
3031     assert(_null_path == PATH_LIMIT-1, "delete last");
3032     region->del_req(_null_path);
3033     phi   ->del_req(_null_path);
3034   }
3035 
3036   // Do we know the type check always succeed?
3037   bool known_statically = false;
3038   if (_gvn.type(superklass)->singleton()) {
3039     ciKlass* superk = _gvn.type(superklass)->is_klassptr()->klass();
3040     ciKlass* subk = _gvn.type(obj)->is_oopptr()->klass();
3041     if (subk != NULL && subk->is_loaded()) {
3042       int static_res = C->static_subtype_check(superk, subk);
3043       known_statically = (static_res == Compile::SSC_always_true || static_res == Compile::SSC_always_false);
3044     }
3045   }
3046 
3047   if (!known_statically) {
3048     const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
3049     // We may not have profiling here or it may not help us. If we
3050     // have a speculative type use it to perform an exact cast.
3051     ciKlass* spec_obj_type = obj_type->speculative_type();
3052     if (spec_obj_type != NULL || (ProfileDynamicTypes && data != NULL)) {
3053       Node* cast_obj = maybe_cast_profiled_receiver(not_null_obj, NULL, spec_obj_type, safe_for_replace);
3054       if (stopped()) {            // Profile disagrees with this path.
3055         set_control(null_ctl);    // Null is the only remaining possibility.
3056         return intcon(0);
3057       }
3058       if (cast_obj != NULL) {
3059         not_null_obj = cast_obj;
3060       }
3061     }
3062   }
3063 
3064   // Load the object's klass
3065   Node* obj_klass = load_object_klass(not_null_obj);
3066 
3067   // Generate the subtype check
3068   Node* not_subtype_ctrl = gen_subtype_check(obj_klass, superklass);
3069 
3070   // Plug in the success path to the general merge in slot 1.
3071   region->init_req(_obj_path, control());
3072   phi   ->init_req(_obj_path, intcon(1));
3073 
3074   // Plug in the failing path to the general merge in slot 2.
3075   region->init_req(_fail_path, not_subtype_ctrl);
3076   phi   ->init_req(_fail_path, intcon(0));
3077 
3078   // Return final merged results
3079   set_control( _gvn.transform(region) );
3080   record_for_igvn(region);
3081 
3082   // If we know the type check always succeeds then we don't use the
3083   // profiling data at this bytecode. Don't lose it, feed it to the
3084   // type system as a speculative type.
3085   if (safe_for_replace) {
3086     Node* casted_obj = record_profiled_receiver_for_speculation(obj);
3087     replace_in_map(obj, casted_obj);
3088   }
3089 
3090   return _gvn.transform(phi);
3091 }
3092 
3093 //-------------------------------gen_checkcast---------------------------------
3094 // Generate a checkcast idiom.  Used by both the checkcast bytecode and the
3095 // array store bytecode.  Stack must be as-if BEFORE doing the bytecode so the
3096 // uncommon-trap paths work.  Adjust stack after this call.
3097 // If failure_control is supplied and not null, it is filled in with
3098 // the control edge for the cast failure.  Otherwise, an appropriate
3099 // uncommon trap or exception is thrown.
3100 Node* GraphKit::gen_checkcast(Node *obj, Node* superklass,
3101                               Node* *failure_control) {
3102   kill_dead_locals();           // Benefit all the uncommon traps
3103   const TypeKlassPtr *tk = _gvn.type(superklass)->is_klassptr();
3104   const Type *toop = TypeOopPtr::make_from_klass(tk->klass());
3105 
3106   // Fast cutout:  Check the case that the cast is vacuously true.
3107   // This detects the common cases where the test will short-circuit
3108   // away completely.  We do this before we perform the null check,
3109   // because if the test is going to turn into zero code, we don't
3110   // want a residual null check left around.  (Causes a slowdown,
3111   // for example, in some objArray manipulations, such as a[i]=a[j].)
3112   if (tk->singleton()) {
3113     const TypeOopPtr* objtp = _gvn.type(obj)->isa_oopptr();
3114     if (objtp != NULL && objtp->klass() != NULL) {
3115       switch (C->static_subtype_check(tk->klass(), objtp->klass())) {
3116       case Compile::SSC_always_true:
3117         // If we know the type check always succeed then we don't use
3118         // the profiling data at this bytecode. Don't lose it, feed it
3119         // to the type system as a speculative type.
3120         return record_profiled_receiver_for_speculation(obj);
3121       case Compile::SSC_always_false:
3122         // It needs a null check because a null will *pass* the cast check.
3123         // A non-null value will always produce an exception.
3124         return null_assert(obj);
3125       }
3126     }
3127   }
3128 
3129   ciProfileData* data = NULL;
3130   bool safe_for_replace = false;
3131   if (failure_control == NULL) {        // use MDO in regular case only
3132     assert(java_bc() == Bytecodes::_aastore ||
3133            java_bc() == Bytecodes::_checkcast,
3134            "interpreter profiles type checks only for these BCs");
3135     data = method()->method_data()->bci_to_data(bci());
3136     safe_for_replace = true;
3137   }
3138 
3139   // Make the merge point
3140   enum { _obj_path = 1, _null_path, PATH_LIMIT };
3141   RegionNode* region = new RegionNode(PATH_LIMIT);
3142   Node*       phi    = new PhiNode(region, toop);
3143   C->set_has_split_ifs(true); // Has chance for split-if optimization
3144 
3145   // Use null-cast information if it is available
3146   bool speculative_not_null = false;
3147   bool never_see_null = ((failure_control == NULL)  // regular case only
3148                          && seems_never_null(obj, data, speculative_not_null));
3149 
3150   // Null check; get casted pointer; set region slot 3
3151   Node* null_ctl = top();
3152   Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null, safe_for_replace, speculative_not_null);
3153 
3154   // If not_null_obj is dead, only null-path is taken
3155   if (stopped()) {              // Doing instance-of on a NULL?
3156     set_control(null_ctl);
3157     return null();
3158   }
3159   region->init_req(_null_path, null_ctl);
3160   phi   ->init_req(_null_path, null());  // Set null path value
3161   if (null_ctl == top()) {
3162     // Do this eagerly, so that pattern matches like is_diamond_phi
3163     // will work even during parsing.
3164     assert(_null_path == PATH_LIMIT-1, "delete last");
3165     region->del_req(_null_path);
3166     phi   ->del_req(_null_path);
3167   }
3168 
3169   Node* cast_obj = NULL;
3170   if (tk->klass_is_exact()) {
3171     // The following optimization tries to statically cast the speculative type of the object
3172     // (for example obtained during profiling) to the type of the superklass and then do a
3173     // dynamic check that the type of the object is what we expect. To work correctly
3174     // for checkcast and aastore the type of superklass should be exact.
3175     const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
3176     // We may not have profiling here or it may not help us. If we have
3177     // a speculative type use it to perform an exact cast.
3178     ciKlass* spec_obj_type = obj_type->speculative_type();
3179     if (spec_obj_type != NULL || data != NULL) {
3180       cast_obj = maybe_cast_profiled_receiver(not_null_obj, tk->klass(), spec_obj_type, safe_for_replace);
3181       if (cast_obj != NULL) {
3182         if (failure_control != NULL) // failure is now impossible
3183           (*failure_control) = top();
3184         // adjust the type of the phi to the exact klass:
3185         phi->raise_bottom_type(_gvn.type(cast_obj)->meet_speculative(TypePtr::NULL_PTR));
3186       }
3187     }
3188   }
3189 
3190   if (cast_obj == NULL) {
3191     // Load the object's klass
3192     Node* obj_klass = load_object_klass(not_null_obj);
3193 
3194     // Generate the subtype check
3195     Node* not_subtype_ctrl = gen_subtype_check( obj_klass, superklass );
3196 
3197     // Plug in success path into the merge
3198     cast_obj = _gvn.transform(new CheckCastPPNode(control(), not_null_obj, toop));
3199     // Failure path ends in uncommon trap (or may be dead - failure impossible)
3200     if (failure_control == NULL) {
3201       if (not_subtype_ctrl != top()) { // If failure is possible
3202         PreserveJVMState pjvms(this);
3203         set_control(not_subtype_ctrl);
3204         builtin_throw(Deoptimization::Reason_class_check, obj_klass);
3205       }
3206     } else {
3207       (*failure_control) = not_subtype_ctrl;
3208     }
3209   }
3210 
3211   region->init_req(_obj_path, control());
3212   phi   ->init_req(_obj_path, cast_obj);
3213 
3214   // A merge of NULL or Casted-NotNull obj
3215   Node* res = _gvn.transform(phi);
3216 
3217   // Note I do NOT always 'replace_in_map(obj,result)' here.
3218   //  if( tk->klass()->can_be_primary_super()  )
3219     // This means that if I successfully store an Object into an array-of-String
3220     // I 'forget' that the Object is really now known to be a String.  I have to
3221     // do this because we don't have true union types for interfaces - if I store
3222     // a Baz into an array-of-Interface and then tell the optimizer it's an
3223     // Interface, I forget that it's also a Baz and cannot do Baz-like field
3224     // references to it.  FIX THIS WHEN UNION TYPES APPEAR!
3225   //  replace_in_map( obj, res );
3226 
3227   // Return final merged results
3228   set_control( _gvn.transform(region) );
3229   record_for_igvn(region);
3230 
3231   return record_profiled_receiver_for_speculation(res);
3232 }
3233 
3234 //------------------------------next_monitor-----------------------------------
3235 // What number should be given to the next monitor?
3236 int GraphKit::next_monitor() {
3237   int current = jvms()->monitor_depth()* C->sync_stack_slots();
3238   int next = current + C->sync_stack_slots();
3239   // Keep the toplevel high water mark current:
3240   if (C->fixed_slots() < next)  C->set_fixed_slots(next);
3241   return current;
3242 }
3243 
3244 //------------------------------insert_mem_bar---------------------------------
3245 // Memory barrier to avoid floating things around
3246 // The membar serves as a pinch point between both control and all memory slices.
3247 Node* GraphKit::insert_mem_bar(int opcode, Node* precedent) {
3248   MemBarNode* mb = MemBarNode::make(C, opcode, Compile::AliasIdxBot, precedent);
3249   mb->init_req(TypeFunc::Control, control());
3250   mb->init_req(TypeFunc::Memory,  reset_memory());
3251   Node* membar = _gvn.transform(mb);
3252   set_control(_gvn.transform(new ProjNode(membar, TypeFunc::Control)));
3253   set_all_memory_call(membar);
3254   return membar;
3255 }
3256 
3257 //-------------------------insert_mem_bar_volatile----------------------------
3258 // Memory barrier to avoid floating things around
3259 // The membar serves as a pinch point between both control and memory(alias_idx).
3260 // If you want to make a pinch point on all memory slices, do not use this
3261 // function (even with AliasIdxBot); use insert_mem_bar() instead.
3262 Node* GraphKit::insert_mem_bar_volatile(int opcode, int alias_idx, Node* precedent) {
3263   // When Parse::do_put_xxx updates a volatile field, it appends a series
3264   // of MemBarVolatile nodes, one for *each* volatile field alias category.
3265   // The first membar is on the same memory slice as the field store opcode.
3266   // This forces the membar to follow the store.  (Bug 6500685 broke this.)
3267   // All the other membars (for other volatile slices, including AliasIdxBot,
3268   // which stands for all unknown volatile slices) are control-dependent
3269   // on the first membar.  This prevents later volatile loads or stores
3270   // from sliding up past the just-emitted store.
3271 
3272   MemBarNode* mb = MemBarNode::make(C, opcode, alias_idx, precedent);
3273   mb->set_req(TypeFunc::Control,control());
3274   if (alias_idx == Compile::AliasIdxBot) {
3275     mb->set_req(TypeFunc::Memory, merged_memory()->base_memory());
3276   } else {
3277     assert(!(opcode == Op_Initialize && alias_idx != Compile::AliasIdxRaw), "fix caller");
3278     mb->set_req(TypeFunc::Memory, memory(alias_idx));
3279   }
3280   Node* membar = _gvn.transform(mb);
3281   set_control(_gvn.transform(new ProjNode(membar, TypeFunc::Control)));
3282   if (alias_idx == Compile::AliasIdxBot) {
3283     merged_memory()->set_base_memory(_gvn.transform(new ProjNode(membar, TypeFunc::Memory)));
3284   } else {
3285     set_memory(_gvn.transform(new ProjNode(membar, TypeFunc::Memory)),alias_idx);
3286   }
3287   return membar;
3288 }
3289 
3290 //------------------------------shared_lock------------------------------------
3291 // Emit locking code.
3292 FastLockNode* GraphKit::shared_lock(Node* obj) {
3293   // bci is either a monitorenter bc or InvocationEntryBci
3294   // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
3295   assert(SynchronizationEntryBCI == InvocationEntryBci, "");
3296 
3297   if( !GenerateSynchronizationCode )
3298     return NULL;                // Not locking things?
3299   if (stopped())                // Dead monitor?
3300     return NULL;
3301 
3302   assert(dead_locals_are_killed(), "should kill locals before sync. point");
3303 
3304   // Box the stack location
3305   Node* box = _gvn.transform(new BoxLockNode(next_monitor()));
3306   Node* mem = reset_memory();
3307 
3308   FastLockNode * flock = _gvn.transform(new FastLockNode(0, obj, box) )->as_FastLock();
3309   if (UseBiasedLocking && PrintPreciseBiasedLockingStatistics) {
3310     // Create the counters for this fast lock.
3311     flock->create_lock_counter(sync_jvms()); // sync_jvms used to get current bci
3312   }
3313 
3314   // Create the rtm counters for this fast lock if needed.
3315   flock->create_rtm_lock_counter(sync_jvms()); // sync_jvms used to get current bci
3316 
3317   // Add monitor to debug info for the slow path.  If we block inside the
3318   // slow path and de-opt, we need the monitor hanging around
3319   map()->push_monitor( flock );
3320 
3321   const TypeFunc *tf = LockNode::lock_type();
3322   LockNode *lock = new LockNode(C, tf);
3323 
3324   lock->init_req( TypeFunc::Control, control() );
3325   lock->init_req( TypeFunc::Memory , mem );
3326   lock->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
3327   lock->init_req( TypeFunc::FramePtr, frameptr() );
3328   lock->init_req( TypeFunc::ReturnAdr, top() );
3329 
3330   lock->init_req(TypeFunc::Parms + 0, obj);
3331   lock->init_req(TypeFunc::Parms + 1, box);
3332   lock->init_req(TypeFunc::Parms + 2, flock);
3333   add_safepoint_edges(lock);
3334 
3335   lock = _gvn.transform( lock )->as_Lock();
3336 
3337   // lock has no side-effects, sets few values
3338   set_predefined_output_for_runtime_call(lock, mem, TypeRawPtr::BOTTOM);
3339 
3340   insert_mem_bar(Op_MemBarAcquireLock);
3341 
3342   // Add this to the worklist so that the lock can be eliminated
3343   record_for_igvn(lock);
3344 
3345 #ifndef PRODUCT
3346   if (PrintLockStatistics) {
3347     // Update the counter for this lock.  Don't bother using an atomic
3348     // operation since we don't require absolute accuracy.
3349     lock->create_lock_counter(map()->jvms());
3350     increment_counter(lock->counter()->addr());
3351   }
3352 #endif
3353 
3354   return flock;
3355 }
3356 
3357 
3358 //------------------------------shared_unlock----------------------------------
3359 // Emit unlocking code.
3360 void GraphKit::shared_unlock(Node* box, Node* obj) {
3361   // bci is either a monitorenter bc or InvocationEntryBci
3362   // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
3363   assert(SynchronizationEntryBCI == InvocationEntryBci, "");
3364 
3365   if( !GenerateSynchronizationCode )
3366     return;
3367   if (stopped()) {               // Dead monitor?
3368     map()->pop_monitor();        // Kill monitor from debug info
3369     return;
3370   }
3371 
3372   // Memory barrier to avoid floating things down past the locked region
3373   insert_mem_bar(Op_MemBarReleaseLock);
3374 
3375   const TypeFunc *tf = OptoRuntime::complete_monitor_exit_Type();
3376   UnlockNode *unlock = new UnlockNode(C, tf);
3377 #ifdef ASSERT
3378   unlock->set_dbg_jvms(sync_jvms());
3379 #endif
3380   uint raw_idx = Compile::AliasIdxRaw;
3381   unlock->init_req( TypeFunc::Control, control() );
3382   unlock->init_req( TypeFunc::Memory , memory(raw_idx) );
3383   unlock->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
3384   unlock->init_req( TypeFunc::FramePtr, frameptr() );
3385   unlock->init_req( TypeFunc::ReturnAdr, top() );
3386 
3387   unlock->init_req(TypeFunc::Parms + 0, obj);
3388   unlock->init_req(TypeFunc::Parms + 1, box);
3389   unlock = _gvn.transform(unlock)->as_Unlock();
3390 
3391   Node* mem = reset_memory();
3392 
3393   // unlock has no side-effects, sets few values
3394   set_predefined_output_for_runtime_call(unlock, mem, TypeRawPtr::BOTTOM);
3395 
3396   // Kill monitor from debug info
3397   map()->pop_monitor( );
3398 }
3399 
3400 //-------------------------------get_layout_helper-----------------------------
3401 // If the given klass is a constant or known to be an array,
3402 // fetch the constant layout helper value into constant_value
3403 // and return (Node*)NULL.  Otherwise, load the non-constant
3404 // layout helper value, and return the node which represents it.
3405 // This two-faced routine is useful because allocation sites
3406 // almost always feature constant types.
3407 Node* GraphKit::get_layout_helper(Node* klass_node, jint& constant_value) {
3408   const TypeKlassPtr* inst_klass = _gvn.type(klass_node)->isa_klassptr();
3409   if (!StressReflectiveCode && inst_klass != NULL) {
3410     ciKlass* klass = inst_klass->klass();
3411     assert(klass != NULL, "klass should not be NULL");
3412     bool    xklass = inst_klass->klass_is_exact();
3413     if (xklass || klass->is_array_klass()) {
3414       jint lhelper = klass->layout_helper();
3415       if (lhelper != Klass::_lh_neutral_value) {
3416         constant_value = lhelper;
3417         return (Node*) NULL;
3418       }
3419     }
3420   }
3421   constant_value = Klass::_lh_neutral_value;  // put in a known value
3422   Node* lhp = basic_plus_adr(klass_node, klass_node, in_bytes(Klass::layout_helper_offset()));
3423   return make_load(NULL, lhp, TypeInt::INT, T_INT, MemNode::unordered);
3424 }
3425 
3426 // We just put in an allocate/initialize with a big raw-memory effect.
3427 // Hook selected additional alias categories on the initialization.
3428 static void hook_memory_on_init(GraphKit& kit, int alias_idx,
3429                                 MergeMemNode* init_in_merge,
3430                                 Node* init_out_raw) {
3431   DEBUG_ONLY(Node* init_in_raw = init_in_merge->base_memory());
3432   assert(init_in_merge->memory_at(alias_idx) == init_in_raw, "");
3433 
3434   Node* prevmem = kit.memory(alias_idx);
3435   init_in_merge->set_memory_at(alias_idx, prevmem);
3436   kit.set_memory(init_out_raw, alias_idx);
3437 }
3438 
3439 //---------------------------set_output_for_allocation-------------------------
3440 Node* GraphKit::set_output_for_allocation(AllocateNode* alloc,
3441                                           const TypeOopPtr* oop_type,
3442                                           bool deoptimize_on_exception) {
3443   int rawidx = Compile::AliasIdxRaw;
3444   alloc->set_req( TypeFunc::FramePtr, frameptr() );
3445   add_safepoint_edges(alloc);
3446   Node* allocx = _gvn.transform(alloc);
3447   set_control( _gvn.transform(new ProjNode(allocx, TypeFunc::Control) ) );
3448   // create memory projection for i_o
3449   set_memory ( _gvn.transform( new ProjNode(allocx, TypeFunc::Memory, true) ), rawidx );
3450   make_slow_call_ex(allocx, env()->Throwable_klass(), true, deoptimize_on_exception);
3451 
3452   // create a memory projection as for the normal control path
3453   Node* malloc = _gvn.transform(new ProjNode(allocx, TypeFunc::Memory));
3454   set_memory(malloc, rawidx);
3455 
3456   // a normal slow-call doesn't change i_o, but an allocation does
3457   // we create a separate i_o projection for the normal control path
3458   set_i_o(_gvn.transform( new ProjNode(allocx, TypeFunc::I_O, false) ) );
3459   Node* rawoop = _gvn.transform( new ProjNode(allocx, TypeFunc::Parms) );
3460 
3461   // put in an initialization barrier
3462   InitializeNode* init = insert_mem_bar_volatile(Op_Initialize, rawidx,
3463                                                  rawoop)->as_Initialize();
3464   assert(alloc->initialization() == init,  "2-way macro link must work");
3465   assert(init ->allocation()     == alloc, "2-way macro link must work");
3466   {
3467     // Extract memory strands which may participate in the new object's
3468     // initialization, and source them from the new InitializeNode.
3469     // This will allow us to observe initializations when they occur,
3470     // and link them properly (as a group) to the InitializeNode.
3471     assert(init->in(InitializeNode::Memory) == malloc, "");
3472     MergeMemNode* minit_in = MergeMemNode::make(malloc);
3473     init->set_req(InitializeNode::Memory, minit_in);
3474     record_for_igvn(minit_in); // fold it up later, if possible
3475     Node* minit_out = memory(rawidx);
3476     assert(minit_out->is_Proj() && minit_out->in(0) == init, "");
3477     if (oop_type->isa_aryptr()) {
3478       const TypeAryPtr* arytype = oop_type->is_aryptr();
3479       if (arytype->klass()->is_value_array_klass()) {
3480         ciValueArrayKlass* vak = arytype->klass()->as_value_array_klass();
3481         ciValueKlass* vk = vak->element_klass()->as_value_klass();
3482         for (int i = 0, len = vk->nof_nonstatic_fields(); i < len; i++) {
3483           ciField* field = vk->nonstatic_field_at(i);
3484           if (field->offset() >= TrackedInitializationLimit * HeapWordSize)
3485             continue;  // do not bother to track really large numbers of fields
3486           int off_in_vt = field->offset() - vk->first_field_offset();
3487           const TypePtr* adr_type = arytype->with_field_offset(off_in_vt)->add_offset(Type::OffsetBot);
3488           int fieldidx = C->get_alias_index(adr_type);
3489           hook_memory_on_init(*this, fieldidx, minit_in, minit_out);
3490         }
3491       } else {
3492         const TypePtr* telemref = oop_type->add_offset(Type::OffsetBot);
3493         int            elemidx  = C->get_alias_index(telemref);
3494         hook_memory_on_init(*this, elemidx, minit_in, minit_out);
3495       }
3496     } else if (oop_type->isa_instptr() || oop_type->isa_valuetypeptr()) {
3497       ciInstanceKlass* ik = oop_type->klass()->as_instance_klass();
3498       for (int i = 0, len = ik->nof_nonstatic_fields(); i < len; i++) {
3499         ciField* field = ik->nonstatic_field_at(i);
3500         if (field->offset() >= TrackedInitializationLimit * HeapWordSize)
3501           continue;  // do not bother to track really large numbers of fields
3502         // Find (or create) the alias category for this field:
3503         int fieldidx = C->alias_type(field)->index();
3504         hook_memory_on_init(*this, fieldidx, minit_in, minit_out);
3505       }
3506     }
3507   }
3508 
3509   // Cast raw oop to the real thing...
3510   Node* javaoop = new CheckCastPPNode(control(), rawoop, oop_type);
3511   javaoop = _gvn.transform(javaoop);
3512   C->set_recent_alloc(control(), javaoop);
3513   assert(just_allocated_object(control()) == javaoop, "just allocated");
3514 
3515 #ifdef ASSERT
3516   { // Verify that the AllocateNode::Ideal_allocation recognizers work:
3517     assert(AllocateNode::Ideal_allocation(rawoop, &_gvn) == alloc,
3518            "Ideal_allocation works");
3519     assert(AllocateNode::Ideal_allocation(javaoop, &_gvn) == alloc,
3520            "Ideal_allocation works");
3521     if (alloc->is_AllocateArray()) {
3522       assert(AllocateArrayNode::Ideal_array_allocation(rawoop, &_gvn) == alloc->as_AllocateArray(),
3523              "Ideal_allocation works");
3524       assert(AllocateArrayNode::Ideal_array_allocation(javaoop, &_gvn) == alloc->as_AllocateArray(),
3525              "Ideal_allocation works");
3526     } else {
3527       assert(alloc->in(AllocateNode::ALength)->is_top(), "no length, please");
3528     }
3529   }
3530 #endif //ASSERT
3531 
3532   return javaoop;
3533 }
3534 
3535 //---------------------------new_instance--------------------------------------
3536 // This routine takes a klass_node which may be constant (for a static type)
3537 // or may be non-constant (for reflective code).  It will work equally well
3538 // for either, and the graph will fold nicely if the optimizer later reduces
3539 // the type to a constant.
3540 // The optional arguments are for specialized use by intrinsics:
3541 //  - If 'extra_slow_test' if not null is an extra condition for the slow-path.
3542 //  - If 'return_size_val', report the the total object size to the caller.
3543 //  - deoptimize_on_exception controls how Java exceptions are handled (rethrow vs deoptimize)
3544 Node* GraphKit::new_instance(Node* klass_node,
3545                              Node* extra_slow_test,
3546                              Node* *return_size_val,
3547                              bool deoptimize_on_exception,
3548                              ValueTypeBaseNode* value_node) {
3549   // Compute size in doublewords
3550   // The size is always an integral number of doublewords, represented
3551   // as a positive bytewise size stored in the klass's layout_helper.
3552   // The layout_helper also encodes (in a low bit) the need for a slow path.
3553   jint  layout_con = Klass::_lh_neutral_value;
3554   Node* layout_val = get_layout_helper(klass_node, layout_con);
3555   bool  layout_is_con = (layout_val == NULL);
3556 
3557   if (extra_slow_test == NULL)  extra_slow_test = intcon(0);
3558   // Generate the initial go-slow test.  It's either ALWAYS (return a
3559   // Node for 1) or NEVER (return a NULL) or perhaps (in the reflective
3560   // case) a computed value derived from the layout_helper.
3561   Node* initial_slow_test = NULL;
3562   if (layout_is_con) {
3563     assert(!StressReflectiveCode, "stress mode does not use these paths");
3564     bool must_go_slow = Klass::layout_helper_needs_slow_path(layout_con);
3565     initial_slow_test = must_go_slow ? intcon(1) : extra_slow_test;
3566   } else {   // reflective case
3567     // This reflective path is used by Unsafe.allocateInstance.
3568     // (It may be stress-tested by specifying StressReflectiveCode.)
3569     // Basically, we want to get into the VM is there's an illegal argument.
3570     Node* bit = intcon(Klass::_lh_instance_slow_path_bit);
3571     initial_slow_test = _gvn.transform( new AndINode(layout_val, bit) );
3572     if (extra_slow_test != intcon(0)) {
3573       initial_slow_test = _gvn.transform( new OrINode(initial_slow_test, extra_slow_test) );
3574     }
3575     // (Macro-expander will further convert this to a Bool, if necessary.)
3576   }
3577 
3578   // Find the size in bytes.  This is easy; it's the layout_helper.
3579   // The size value must be valid even if the slow path is taken.
3580   Node* size = NULL;
3581   if (layout_is_con) {
3582     size = MakeConX(Klass::layout_helper_size_in_bytes(layout_con));
3583   } else {   // reflective case
3584     // This reflective path is used by clone and Unsafe.allocateInstance.
3585     size = ConvI2X(layout_val);
3586 
3587     // Clear the low bits to extract layout_helper_size_in_bytes:
3588     assert((int)Klass::_lh_instance_slow_path_bit < BytesPerLong, "clear bit");
3589     Node* mask = MakeConX(~ (intptr_t)right_n_bits(LogBytesPerLong));
3590     size = _gvn.transform( new AndXNode(size, mask) );
3591   }
3592   if (return_size_val != NULL) {
3593     (*return_size_val) = size;
3594   }
3595 
3596   // This is a precise notnull oop of the klass.
3597   // (Actually, it need not be precise if this is a reflective allocation.)
3598   // It's what we cast the result to.
3599   const TypeKlassPtr* tklass = _gvn.type(klass_node)->isa_klassptr();
3600   if (!tklass)  tklass = TypeKlassPtr::OBJECT;
3601   const TypeOopPtr* oop_type = tklass->as_instance_type();
3602 
3603   // Now generate allocation code
3604 
3605   // The entire memory state is needed for slow path of the allocation
3606   // since GC and deoptimization can happen.
3607   Node *mem = reset_memory();
3608   set_all_memory(mem); // Create new memory state
3609 
3610   AllocateNode* alloc = new AllocateNode(C, AllocateNode::alloc_type(Type::TOP),
3611                                          control(), mem, i_o(),
3612                                          size, klass_node,
3613                                          initial_slow_test, value_node);
3614 
3615   return set_output_for_allocation(alloc, oop_type, deoptimize_on_exception);
3616 }
3617 
3618 //-------------------------------new_array-------------------------------------
3619 // helper for newarray and anewarray
3620 // The 'length' parameter is (obviously) the length of the array.
3621 // See comments on new_instance for the meaning of the other arguments.
3622 Node* GraphKit::new_array(Node* klass_node,     // array klass (maybe variable)
3623                           Node* length,         // number of array elements
3624                           int   nargs,          // number of arguments to push back for uncommon trap
3625                           Node* *return_size_val,
3626                           bool deoptimize_on_exception) {
3627   jint  layout_con = Klass::_lh_neutral_value;
3628   Node* layout_val = get_layout_helper(klass_node, layout_con);
3629   bool  layout_is_con = (layout_val == NULL);
3630 
3631   if (!layout_is_con && !StressReflectiveCode &&
3632       !too_many_traps(Deoptimization::Reason_class_check)) {
3633     // This is a reflective array creation site.
3634     // Optimistically assume that it is a subtype of Object[],
3635     // so that we can fold up all the address arithmetic.
3636     layout_con = Klass::array_layout_helper(T_OBJECT);
3637     Node* cmp_lh = _gvn.transform( new CmpINode(layout_val, intcon(layout_con)) );
3638     Node* bol_lh = _gvn.transform( new BoolNode(cmp_lh, BoolTest::eq) );
3639     { BuildCutout unless(this, bol_lh, PROB_MAX);
3640       inc_sp(nargs);
3641       uncommon_trap(Deoptimization::Reason_class_check,
3642                     Deoptimization::Action_maybe_recompile);
3643     }
3644     layout_val = NULL;
3645     layout_is_con = true;
3646   }
3647 
3648   // Generate the initial go-slow test.  Make sure we do not overflow
3649   // if length is huge (near 2Gig) or negative!  We do not need
3650   // exact double-words here, just a close approximation of needed
3651   // double-words.  We can't add any offset or rounding bits, lest we
3652   // take a size -1 of bytes and make it positive.  Use an unsigned
3653   // compare, so negative sizes look hugely positive.
3654   int fast_size_limit = FastAllocateSizeLimit;
3655   if (layout_is_con) {
3656     assert(!StressReflectiveCode, "stress mode does not use these paths");
3657     // Increase the size limit if we have exact knowledge of array type.
3658     int log2_esize = Klass::layout_helper_log2_element_size(layout_con);
3659     fast_size_limit <<= (LogBytesPerLong - log2_esize);
3660   }
3661 
3662   Node* initial_slow_cmp  = _gvn.transform( new CmpUNode( length, intcon( fast_size_limit ) ) );
3663   Node* initial_slow_test = _gvn.transform( new BoolNode( initial_slow_cmp, BoolTest::gt ) );
3664 
3665   // --- Size Computation ---
3666   // array_size = round_to_heap(array_header + (length << elem_shift));
3667   // where round_to_heap(x) == align_to(x, MinObjAlignmentInBytes)
3668   // and align_to(x, y) == ((x + y-1) & ~(y-1))
3669   // The rounding mask is strength-reduced, if possible.
3670   int round_mask = MinObjAlignmentInBytes - 1;
3671   Node* header_size = NULL;
3672   int   header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
3673   // (T_BYTE has the weakest alignment and size restrictions...)
3674   if (layout_is_con) {
3675     int       hsize  = Klass::layout_helper_header_size(layout_con);
3676     int       eshift = Klass::layout_helper_log2_element_size(layout_con);
3677     BasicType etype  = Klass::layout_helper_element_type(layout_con);
3678     bool is_value_array = Klass::layout_helper_is_valueArray(layout_con);
3679     if ((round_mask & ~right_n_bits(eshift)) == 0)
3680       round_mask = 0;  // strength-reduce it if it goes away completely
3681     assert(is_value_array || (hsize & right_n_bits(eshift)) == 0, "hsize is pre-rounded");
3682     assert(header_size_min <= hsize, "generic minimum is smallest");
3683     header_size_min = hsize;
3684     header_size = intcon(hsize + round_mask);
3685   } else {
3686     Node* hss   = intcon(Klass::_lh_header_size_shift);
3687     Node* hsm   = intcon(Klass::_lh_header_size_mask);
3688     Node* hsize = _gvn.transform( new URShiftINode(layout_val, hss) );
3689     hsize       = _gvn.transform( new AndINode(hsize, hsm) );
3690     Node* mask  = intcon(round_mask);
3691     header_size = _gvn.transform( new AddINode(hsize, mask) );
3692   }
3693 
3694   Node* elem_shift = NULL;
3695   if (layout_is_con) {
3696     int eshift = Klass::layout_helper_log2_element_size(layout_con);
3697     if (eshift != 0)
3698       elem_shift = intcon(eshift);
3699   } else {
3700     // There is no need to mask or shift this value.
3701     // The semantics of LShiftINode include an implicit mask to 0x1F.
3702     assert(Klass::_lh_log2_element_size_shift == 0, "use shift in place");
3703     elem_shift = layout_val;
3704   }
3705 
3706   // Transition to native address size for all offset calculations:
3707   Node* lengthx = ConvI2X(length);
3708   Node* headerx = ConvI2X(header_size);
3709 #ifdef _LP64
3710   { const TypeInt* tilen = _gvn.find_int_type(length);
3711     if (tilen != NULL && tilen->_lo < 0) {
3712       // Add a manual constraint to a positive range.  Cf. array_element_address.
3713       jint size_max = fast_size_limit;
3714       if (size_max > tilen->_hi)  size_max = tilen->_hi;
3715       const TypeInt* tlcon = TypeInt::make(0, size_max, Type::WidenMin);
3716 
3717       // Only do a narrow I2L conversion if the range check passed.
3718       IfNode* iff = new IfNode(control(), initial_slow_test, PROB_MIN, COUNT_UNKNOWN);
3719       _gvn.transform(iff);
3720       RegionNode* region = new RegionNode(3);
3721       _gvn.set_type(region, Type::CONTROL);
3722       lengthx = new PhiNode(region, TypeLong::LONG);
3723       _gvn.set_type(lengthx, TypeLong::LONG);
3724 
3725       // Range check passed. Use ConvI2L node with narrow type.
3726       Node* passed = IfFalse(iff);
3727       region->init_req(1, passed);
3728       // Make I2L conversion control dependent to prevent it from
3729       // floating above the range check during loop optimizations.
3730       lengthx->init_req(1, C->constrained_convI2L(&_gvn, length, tlcon, passed));
3731 
3732       // Range check failed. Use ConvI2L with wide type because length may be invalid.
3733       region->init_req(2, IfTrue(iff));
3734       lengthx->init_req(2, ConvI2X(length));
3735 
3736       set_control(region);
3737       record_for_igvn(region);
3738       record_for_igvn(lengthx);
3739     }
3740   }
3741 #endif
3742 
3743   // Combine header size (plus rounding) and body size.  Then round down.
3744   // This computation cannot overflow, because it is used only in two
3745   // places, one where the length is sharply limited, and the other
3746   // after a successful allocation.
3747   Node* abody = lengthx;
3748   if (elem_shift != NULL)
3749     abody     = _gvn.transform( new LShiftXNode(lengthx, elem_shift) );
3750   Node* size  = _gvn.transform( new AddXNode(headerx, abody) );
3751   if (round_mask != 0) {
3752     Node* mask = MakeConX(~round_mask);
3753     size       = _gvn.transform( new AndXNode(size, mask) );
3754   }
3755   // else if round_mask == 0, the size computation is self-rounding
3756 
3757   if (return_size_val != NULL) {
3758     // This is the size
3759     (*return_size_val) = size;
3760   }
3761 
3762   // Now generate allocation code
3763 
3764   // The entire memory state is needed for slow path of the allocation
3765   // since GC and deoptimization can happen.
3766   Node *mem = reset_memory();
3767   set_all_memory(mem); // Create new memory state
3768 
3769   if (initial_slow_test->is_Bool()) {
3770     // Hide it behind a CMoveI, or else PhaseIdealLoop::split_up will get sick.
3771     initial_slow_test = initial_slow_test->as_Bool()->as_int_value(&_gvn);
3772   }
3773 
3774   // Create the AllocateArrayNode and its result projections
3775   AllocateArrayNode* alloc
3776     = new AllocateArrayNode(C, AllocateArrayNode::alloc_type(TypeInt::INT),
3777                             control(), mem, i_o(),
3778                             size, klass_node,
3779                             initial_slow_test,
3780                             length);
3781 
3782   // Cast to correct type.  Note that the klass_node may be constant or not,
3783   // and in the latter case the actual array type will be inexact also.
3784   // (This happens via a non-constant argument to inline_native_newArray.)
3785   // In any case, the value of klass_node provides the desired array type.
3786   const TypeInt* length_type = _gvn.find_int_type(length);
3787   const TypeOopPtr* ary_type = _gvn.type(klass_node)->is_klassptr()->as_instance_type();
3788   if (ary_type->isa_aryptr() && length_type != NULL) {
3789     // Try to get a better type than POS for the size
3790     ary_type = ary_type->is_aryptr()->cast_to_size(length_type);
3791   }
3792 
3793   Node* javaoop = set_output_for_allocation(alloc, ary_type, deoptimize_on_exception);
3794 
3795   // Cast length on remaining path to be as narrow as possible
3796   if (map()->find_edge(length) >= 0) {
3797     Node* ccast = alloc->make_ideal_length(ary_type, &_gvn);
3798     if (ccast != length) {
3799       _gvn.set_type_bottom(ccast);
3800       record_for_igvn(ccast);
3801       replace_in_map(length, ccast);
3802     }
3803   }
3804 
3805   const TypeAryPtr* ary_ptr = ary_type->isa_aryptr();
3806   ciKlass* elem_klass = ary_ptr != NULL ? ary_ptr->klass()->as_array_klass()->element_klass() : NULL;
3807   if (elem_klass != NULL && elem_klass->is_valuetype()) {
3808     ciValueKlass* vk = elem_klass->as_value_klass();
3809     if (!vk->flatten_array()) {
3810       // Non-flattened value type arrays need to be initialized with default value type oops
3811       initialize_value_type_array(javaoop, length, elem_klass->as_value_klass(), nargs);
3812       // TODO re-enable once JDK-8189802 is fixed
3813       // InitializeNode* init = alloc->initialization();
3814       //init->set_complete_with_arraycopy();
3815     }
3816   }
3817 
3818   return javaoop;
3819 }
3820 
3821 void GraphKit::initialize_value_type_array(Node* array, Node* length, ciValueKlass* vk, int nargs) {
3822   // Check for zero length
3823   Node* null_ctl = top();
3824   null_check_common(length, T_INT, false, &null_ctl, false);
3825   if (stopped()) {
3826     set_control(null_ctl); // Always zero
3827     return;
3828   }
3829 
3830   RegionNode* res_ctl = new RegionNode(3);
3831   gvn().set_type(res_ctl, Type::CONTROL);
3832   record_for_igvn(res_ctl);
3833 
3834   // Length is zero: don't execute initialization loop
3835   res_ctl->init_req(1, null_ctl);
3836   PhiNode* res_io  = PhiNode::make(res_ctl, i_o(), Type::ABIO);
3837   PhiNode* res_mem = PhiNode::make(res_ctl, merged_memory(), Type::MEMORY, TypePtr::BOTTOM);
3838   gvn().set_type(res_io, Type::ABIO);
3839   gvn().set_type(res_mem, Type::MEMORY);
3840   record_for_igvn(res_io);
3841   record_for_igvn(res_mem);
3842 
3843   // Length is non-zero: execute a loop that initializes the array with the default value type
3844   Node* oop = ValueTypeNode::load_default_oop(gvn(), vk);
3845 
3846   add_predicate(nargs);
3847   RegionNode* loop = new RegionNode(3);
3848   loop->init_req(1, control());
3849   PhiNode* index = PhiNode::make(loop, intcon(0), TypeInt::INT);
3850   PhiNode* mem   = PhiNode::make(loop, reset_memory(), Type::MEMORY, TypePtr::BOTTOM);
3851 
3852   gvn().set_type(loop, Type::CONTROL);
3853   gvn().set_type(index, TypeInt::INT);
3854   gvn().set_type(mem, Type::MEMORY);
3855   record_for_igvn(loop);
3856   record_for_igvn(index);
3857   record_for_igvn(mem);
3858 
3859   // Loop body: initialize array element at 'index'
3860   set_control(loop);
3861   set_all_memory(mem);
3862   Node* adr = array_element_address(array, index, T_OBJECT);
3863   const TypeOopPtr* elemtype = TypeValueTypePtr::make(TypePtr::NotNull, vk);
3864   store_oop_to_array(control(), array, adr, TypeAryPtr::OOPS, oop, elemtype, T_VALUETYPE, MemNode::release);
3865 
3866   // Check if we need to execute another loop iteration
3867   length = SubI(length, intcon(1));
3868   IfNode* iff = create_and_map_if(control(), Bool(CmpI(index, length), BoolTest::lt), PROB_FAIR, COUNT_UNKNOWN);
3869 
3870   // Continue with next iteration
3871   loop->init_req(2, IfTrue(iff));
3872   index->init_req(2, AddI(index, intcon(1)));
3873   mem->init_req(2, merged_memory());
3874 
3875   // Exit loop
3876   res_ctl->init_req(2, IfFalse(iff));
3877   res_io->set_req(2, i_o());
3878   res_mem->set_req(2, reset_memory());
3879 
3880   // Set merged control, IO and memory
3881   set_control(res_ctl);
3882   set_i_o(res_io);
3883   set_all_memory(res_mem);
3884 }
3885 
3886 // The following "Ideal_foo" functions are placed here because they recognize
3887 // the graph shapes created by the functions immediately above.
3888 
3889 //---------------------------Ideal_allocation----------------------------------
3890 // Given an oop pointer or raw pointer, see if it feeds from an AllocateNode.
3891 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase) {
3892   if (ptr == NULL) {     // reduce dumb test in callers
3893     return NULL;
3894   }
3895   if (ptr->is_CheckCastPP()) { // strip only one raw-to-oop cast
3896     ptr = ptr->in(1);
3897     if (ptr == NULL) return NULL;
3898   }
3899   // Return NULL for allocations with several casts:
3900   //   j.l.reflect.Array.newInstance(jobject, jint)
3901   //   Object.clone()
3902   // to keep more precise type from last cast.
3903   if (ptr->is_Proj()) {
3904     Node* allo = ptr->in(0);
3905     if (allo != NULL && allo->is_Allocate()) {
3906       return allo->as_Allocate();
3907     }
3908   }
3909   // Report failure to match.
3910   return NULL;
3911 }
3912 
3913 // Fancy version which also strips off an offset (and reports it to caller).
3914 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase,
3915                                              intptr_t& offset) {
3916   Node* base = AddPNode::Ideal_base_and_offset(ptr, phase, offset);
3917   if (base == NULL)  return NULL;
3918   return Ideal_allocation(base, phase);
3919 }
3920 
3921 // Trace Initialize <- Proj[Parm] <- Allocate
3922 AllocateNode* InitializeNode::allocation() {
3923   Node* rawoop = in(InitializeNode::RawAddress);
3924   if (rawoop->is_Proj()) {
3925     Node* alloc = rawoop->in(0);
3926     if (alloc->is_Allocate()) {
3927       return alloc->as_Allocate();
3928     }
3929   }
3930   return NULL;
3931 }
3932 
3933 // Trace Allocate -> Proj[Parm] -> Initialize
3934 InitializeNode* AllocateNode::initialization() {
3935   ProjNode* rawoop = proj_out_or_null(AllocateNode::RawAddress);
3936   if (rawoop == NULL)  return NULL;
3937   for (DUIterator_Fast imax, i = rawoop->fast_outs(imax); i < imax; i++) {
3938     Node* init = rawoop->fast_out(i);
3939     if (init->is_Initialize()) {
3940       assert(init->as_Initialize()->allocation() == this, "2-way link");
3941       return init->as_Initialize();
3942     }
3943   }
3944   return NULL;
3945 }
3946 
3947 //----------------------------- loop predicates ---------------------------
3948 
3949 //------------------------------add_predicate_impl----------------------------
3950 void GraphKit::add_predicate_impl(Deoptimization::DeoptReason reason, int nargs) {
3951   // Too many traps seen?
3952   if (too_many_traps(reason)) {
3953 #ifdef ASSERT
3954     if (TraceLoopPredicate) {
3955       int tc = C->trap_count(reason);
3956       tty->print("too many traps=%s tcount=%d in ",
3957                     Deoptimization::trap_reason_name(reason), tc);
3958       method()->print(); // which method has too many predicate traps
3959       tty->cr();
3960     }
3961 #endif
3962     // We cannot afford to take more traps here,
3963     // do not generate predicate.
3964     return;
3965   }
3966 
3967   Node *cont    = _gvn.intcon(1);
3968   Node* opq     = _gvn.transform(new Opaque1Node(C, cont));
3969   Node *bol     = _gvn.transform(new Conv2BNode(opq));
3970   IfNode* iff   = create_and_map_if(control(), bol, PROB_MAX, COUNT_UNKNOWN);
3971   Node* iffalse = _gvn.transform(new IfFalseNode(iff));
3972   C->add_predicate_opaq(opq);
3973   {
3974     PreserveJVMState pjvms(this);
3975     set_control(iffalse);
3976     inc_sp(nargs);
3977     uncommon_trap(reason, Deoptimization::Action_maybe_recompile);
3978   }
3979   Node* iftrue = _gvn.transform(new IfTrueNode(iff));
3980   set_control(iftrue);
3981 }
3982 
3983 //------------------------------add_predicate---------------------------------
3984 void GraphKit::add_predicate(int nargs) {
3985   if (UseLoopPredicate) {
3986     add_predicate_impl(Deoptimization::Reason_predicate, nargs);
3987   }
3988   // loop's limit check predicate should be near the loop.
3989   add_predicate_impl(Deoptimization::Reason_loop_limit_check, nargs);
3990 }
3991 
3992 //----------------------------- store barriers ----------------------------
3993 #define __ ideal.
3994 
3995 void GraphKit::sync_kit(IdealKit& ideal) {
3996   set_all_memory(__ merged_memory());
3997   set_i_o(__ i_o());
3998   set_control(__ ctrl());
3999 }
4000 
4001 void GraphKit::final_sync(IdealKit& ideal) {
4002   // Final sync IdealKit and graphKit.
4003   sync_kit(ideal);
4004 }
4005 
4006 Node* GraphKit::byte_map_base_node() {
4007   // Get base of card map
4008   CardTableModRefBS* ct =
4009     barrier_set_cast<CardTableModRefBS>(Universe::heap()->barrier_set());
4010   assert(sizeof(*ct->byte_map_base) == sizeof(jbyte), "adjust users of this code");
4011   if (ct->byte_map_base != NULL) {
4012     return makecon(TypeRawPtr::make((address)ct->byte_map_base));
4013   } else {
4014     return null();
4015   }
4016 }
4017 
4018 // vanilla/CMS post barrier
4019 // Insert a write-barrier store.  This is to let generational GC work; we have
4020 // to flag all oop-stores before the next GC point.
4021 void GraphKit::write_barrier_post(Node* oop_store,
4022                                   Node* obj,
4023                                   Node* adr,
4024                                   uint  adr_idx,
4025                                   Node* val,
4026                                   bool use_precise) {
4027   // No store check needed if we're storing a NULL or an old object
4028   // (latter case is probably a string constant). The concurrent
4029   // mark sweep garbage collector, however, needs to have all nonNull
4030   // oop updates flagged via card-marks.
4031   if (val != NULL && val->is_Con()) {
4032     // must be either an oop or NULL
4033     const Type* t = val->bottom_type();
4034     if (t == TypePtr::NULL_PTR || t == Type::TOP)
4035       // stores of null never (?) need barriers
4036       return;
4037   }
4038 
4039   if (use_ReduceInitialCardMarks()
4040       && obj == just_allocated_object(control())) {
4041     // We can skip marks on a freshly-allocated object in Eden.
4042     // Keep this code in sync with new_store_pre_barrier() in runtime.cpp.
4043     // That routine informs GC to take appropriate compensating steps,
4044     // upon a slow-path allocation, so as to make this card-mark
4045     // elision safe.
4046     return;
4047   }
4048 
4049   if (!use_precise) {
4050     // All card marks for a (non-array) instance are in one place:
4051     adr = obj;
4052   }
4053   // (Else it's an array (or unknown), and we want more precise card marks.)
4054   assert(adr != NULL, "");
4055 
4056   IdealKit ideal(this, true);
4057 
4058   // Convert the pointer to an int prior to doing math on it
4059   Node* cast = __ CastPX(__ ctrl(), adr);
4060 
4061   // Divide by card size
4062   assert(Universe::heap()->barrier_set()->is_a(BarrierSet::CardTableModRef),
4063          "Only one we handle so far.");
4064   Node* card_offset = __ URShiftX( cast, __ ConI(CardTableModRefBS::card_shift) );
4065 
4066   // Combine card table base and card offset
4067   Node* card_adr = __ AddP(__ top(), byte_map_base_node(), card_offset );
4068 
4069   // Get the alias_index for raw card-mark memory
4070   int adr_type = Compile::AliasIdxRaw;
4071   Node*   zero = __ ConI(0); // Dirty card value
4072   BasicType bt = T_BYTE;
4073 
4074   if (UseConcMarkSweepGC && UseCondCardMark) {
4075     insert_mem_bar(Op_MemBarVolatile);   // StoreLoad barrier
4076     __ sync_kit(this);
4077   }
4078 
4079   if (UseCondCardMark) {
4080     // The classic GC reference write barrier is typically implemented
4081     // as a store into the global card mark table.  Unfortunately
4082     // unconditional stores can result in false sharing and excessive
4083     // coherence traffic as well as false transactional aborts.
4084     // UseCondCardMark enables MP "polite" conditional card mark
4085     // stores.  In theory we could relax the load from ctrl() to
4086     // no_ctrl, but that doesn't buy much latitude.
4087     Node* card_val = __ load( __ ctrl(), card_adr, TypeInt::BYTE, bt, adr_type);
4088     __ if_then(card_val, BoolTest::ne, zero);
4089   }
4090 
4091   // Smash zero into card
4092   if( !UseConcMarkSweepGC ) {
4093     __ store(__ ctrl(), card_adr, zero, bt, adr_type, MemNode::unordered);
4094   } else {
4095     // Specialized path for CM store barrier
4096     __ storeCM(__ ctrl(), card_adr, zero, oop_store, adr_idx, bt, adr_type);
4097   }
4098 
4099   if (UseCondCardMark) {
4100     __ end_if();
4101   }
4102 
4103   // Final sync IdealKit and GraphKit.
4104   final_sync(ideal);
4105 }
4106 /*
4107  * Determine if the G1 pre-barrier can be removed. The pre-barrier is
4108  * required by SATB to make sure all objects live at the start of the
4109  * marking are kept alive, all reference updates need to any previous
4110  * reference stored before writing.
4111  *
4112  * If the previous value is NULL there is no need to save the old value.
4113  * References that are NULL are filtered during runtime by the barrier
4114  * code to avoid unnecessary queuing.
4115  *
4116  * However in the case of newly allocated objects it might be possible to
4117  * prove that the reference about to be overwritten is NULL during compile
4118  * time and avoid adding the barrier code completely.
4119  *
4120  * The compiler needs to determine that the object in which a field is about
4121  * to be written is newly allocated, and that no prior store to the same field
4122  * has happened since the allocation.
4123  *
4124  * Returns true if the pre-barrier can be removed
4125  */
4126 bool GraphKit::g1_can_remove_pre_barrier(PhaseTransform* phase, Node* adr,
4127                                          BasicType bt, uint adr_idx) {
4128   intptr_t offset = 0;
4129   Node* base = AddPNode::Ideal_base_and_offset(adr, phase, offset);
4130   AllocateNode* alloc = AllocateNode::Ideal_allocation(base, phase);
4131 
4132   if (offset == Type::OffsetBot) {
4133     return false; // cannot unalias unless there are precise offsets
4134   }
4135 
4136   if (alloc == NULL) {
4137     return false; // No allocation found
4138   }
4139 
4140   intptr_t size_in_bytes = type2aelembytes(bt);
4141 
4142   Node* mem = memory(adr_idx); // start searching here...
4143 
4144   for (int cnt = 0; cnt < 50; cnt++) {
4145 
4146     if (mem->is_Store()) {
4147 
4148       Node* st_adr = mem->in(MemNode::Address);
4149       intptr_t st_offset = 0;
4150       Node* st_base = AddPNode::Ideal_base_and_offset(st_adr, phase, st_offset);
4151 
4152       if (st_base == NULL) {
4153         break; // inscrutable pointer
4154       }
4155 
4156       // Break we have found a store with same base and offset as ours so break
4157       if (st_base == base && st_offset == offset) {
4158         break;
4159       }
4160 
4161       if (st_offset != offset && st_offset != Type::OffsetBot) {
4162         const int MAX_STORE = BytesPerLong;
4163         if (st_offset >= offset + size_in_bytes ||
4164             st_offset <= offset - MAX_STORE ||
4165             st_offset <= offset - mem->as_Store()->memory_size()) {
4166           // Success:  The offsets are provably independent.
4167           // (You may ask, why not just test st_offset != offset and be done?
4168           // The answer is that stores of different sizes can co-exist
4169           // in the same sequence of RawMem effects.  We sometimes initialize
4170           // a whole 'tile' of array elements with a single jint or jlong.)
4171           mem = mem->in(MemNode::Memory);
4172           continue; // advance through independent store memory
4173         }
4174       }
4175 
4176       if (st_base != base
4177           && MemNode::detect_ptr_independence(base, alloc, st_base,
4178                                               AllocateNode::Ideal_allocation(st_base, phase),
4179                                               phase)) {
4180         // Success:  The bases are provably independent.
4181         mem = mem->in(MemNode::Memory);
4182         continue; // advance through independent store memory
4183       }
4184     } else if (mem->is_Proj() && mem->in(0)->is_Initialize()) {
4185 
4186       InitializeNode* st_init = mem->in(0)->as_Initialize();
4187       AllocateNode* st_alloc = st_init->allocation();
4188 
4189       // Make sure that we are looking at the same allocation site.
4190       // The alloc variable is guaranteed to not be null here from earlier check.
4191       if (alloc == st_alloc) {
4192         // Check that the initialization is storing NULL so that no previous store
4193         // has been moved up and directly write a reference
4194         Node* captured_store = st_init->find_captured_store(offset,
4195                                                             type2aelembytes(T_OBJECT),
4196                                                             phase);
4197         if (captured_store == NULL || captured_store == st_init->zero_memory()) {
4198           return true;
4199         }
4200       }
4201     }
4202 
4203     // Unless there is an explicit 'continue', we must bail out here,
4204     // because 'mem' is an inscrutable memory state (e.g., a call).
4205     break;
4206   }
4207 
4208   return false;
4209 }
4210 
4211 // G1 pre/post barriers
4212 void GraphKit::g1_write_barrier_pre(bool do_load,
4213                                     Node* obj,
4214                                     Node* adr,
4215                                     uint alias_idx,
4216                                     Node* val,
4217                                     const TypeOopPtr* val_type,
4218                                     Node* pre_val,
4219                                     BasicType bt) {
4220 
4221   // Some sanity checks
4222   // Note: val is unused in this routine.
4223 
4224   if (do_load) {
4225     // We need to generate the load of the previous value
4226     assert(obj != NULL, "must have a base");
4227     assert(adr != NULL, "where are loading from?");
4228     assert(pre_val == NULL, "loaded already?");
4229     assert(val_type != NULL, "need a type");
4230 
4231     if (use_ReduceInitialCardMarks()
4232         && g1_can_remove_pre_barrier(&_gvn, adr, bt, alias_idx)) {
4233       return;
4234     }
4235 
4236   } else {
4237     // In this case both val_type and alias_idx are unused.
4238     assert(pre_val != NULL, "must be loaded already");
4239     // Nothing to be done if pre_val is null.
4240     if (pre_val->bottom_type() == TypePtr::NULL_PTR) return;
4241     assert(pre_val->bottom_type()->basic_type() == T_OBJECT, "or we shouldn't be here");
4242   }
4243   assert(bt == T_OBJECT || bt == T_VALUETYPE, "or we shouldn't be here");
4244 
4245   IdealKit ideal(this, true);
4246 
4247   Node* tls = __ thread(); // ThreadLocalStorage
4248 
4249   Node* no_ctrl = NULL;
4250   Node* no_base = __ top();
4251   Node* zero  = __ ConI(0);
4252   Node* zeroX = __ ConX(0);
4253 
4254   float likely  = PROB_LIKELY(0.999);
4255   float unlikely  = PROB_UNLIKELY(0.999);
4256 
4257   BasicType active_type = in_bytes(SATBMarkQueue::byte_width_of_active()) == 4 ? T_INT : T_BYTE;
4258   assert(in_bytes(SATBMarkQueue::byte_width_of_active()) == 4 || in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "flag width");
4259 
4260   // Offsets into the thread
4261   const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() +  // 648
4262                                           SATBMarkQueue::byte_offset_of_active());
4263   const int index_offset   = in_bytes(JavaThread::satb_mark_queue_offset() +  // 656
4264                                           SATBMarkQueue::byte_offset_of_index());
4265   const int buffer_offset  = in_bytes(JavaThread::satb_mark_queue_offset() +  // 652
4266                                           SATBMarkQueue::byte_offset_of_buf());
4267 
4268   // Now the actual pointers into the thread
4269   Node* marking_adr = __ AddP(no_base, tls, __ ConX(marking_offset));
4270   Node* buffer_adr  = __ AddP(no_base, tls, __ ConX(buffer_offset));
4271   Node* index_adr   = __ AddP(no_base, tls, __ ConX(index_offset));
4272 
4273   // Now some of the values
4274   Node* marking = __ load(__ ctrl(), marking_adr, TypeInt::INT, active_type, Compile::AliasIdxRaw);
4275 
4276   // if (!marking)
4277   __ if_then(marking, BoolTest::ne, zero, unlikely); {
4278     BasicType index_bt = TypeX_X->basic_type();
4279     assert(sizeof(size_t) == type2aelembytes(index_bt), "Loading G1 SATBMarkQueue::_index with wrong size.");
4280     Node* index   = __ load(__ ctrl(), index_adr, TypeX_X, index_bt, Compile::AliasIdxRaw);
4281 
4282     if (do_load) {
4283       // load original value
4284       // alias_idx correct??
4285       pre_val = __ load(__ ctrl(), adr, val_type, bt, alias_idx);
4286     }
4287 
4288     // if (pre_val != NULL)
4289     __ if_then(pre_val, BoolTest::ne, null()); {
4290       Node* buffer  = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
4291 
4292       // is the queue for this thread full?
4293       __ if_then(index, BoolTest::ne, zeroX, likely); {
4294 
4295         // decrement the index
4296         Node* next_index = _gvn.transform(new SubXNode(index, __ ConX(sizeof(intptr_t))));
4297 
4298         // Now get the buffer location we will log the previous value into and store it
4299         Node *log_addr = __ AddP(no_base, buffer, next_index);
4300         __ store(__ ctrl(), log_addr, pre_val, T_OBJECT, Compile::AliasIdxRaw, MemNode::unordered);
4301         // update the index
4302         __ store(__ ctrl(), index_adr, next_index, index_bt, Compile::AliasIdxRaw, MemNode::unordered);
4303 
4304       } __ else_(); {
4305 
4306         // logging buffer is full, call the runtime
4307         const TypeFunc *tf = OptoRuntime::g1_wb_pre_Type();
4308         __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_pre), "g1_wb_pre", pre_val, tls);
4309       } __ end_if();  // (!index)
4310     } __ end_if();  // (pre_val != NULL)
4311   } __ end_if();  // (!marking)
4312 
4313   // Final sync IdealKit and GraphKit.
4314   final_sync(ideal);
4315 }
4316 
4317 /*
4318  * G1 similar to any GC with a Young Generation requires a way to keep track of
4319  * references from Old Generation to Young Generation to make sure all live
4320  * objects are found. G1 also requires to keep track of object references
4321  * between different regions to enable evacuation of old regions, which is done
4322  * as part of mixed collections. References are tracked in remembered sets and
4323  * is continuously updated as reference are written to with the help of the
4324  * post-barrier.
4325  *
4326  * To reduce the number of updates to the remembered set the post-barrier
4327  * filters updates to fields in objects located in the Young Generation,
4328  * the same region as the reference, when the NULL is being written or
4329  * if the card is already marked as dirty by an earlier write.
4330  *
4331  * Under certain circumstances it is possible to avoid generating the
4332  * post-barrier completely if it is possible during compile time to prove
4333  * the object is newly allocated and that no safepoint exists between the
4334  * allocation and the store.
4335  *
4336  * In the case of slow allocation the allocation code must handle the barrier
4337  * as part of the allocation in the case the allocated object is not located
4338  * in the nursery, this would happen for humongous objects. This is similar to
4339  * how CMS is required to handle this case, see the comments for the method
4340  * CollectedHeap::new_store_pre_barrier and OptoRuntime::new_store_pre_barrier.
4341  * A deferred card mark is required for these objects and handled in the above
4342  * mentioned methods.
4343  *
4344  * Returns true if the post barrier can be removed
4345  */
4346 bool GraphKit::g1_can_remove_post_barrier(PhaseTransform* phase, Node* store,
4347                                           Node* adr) {
4348   intptr_t      offset = 0;
4349   Node*         base   = AddPNode::Ideal_base_and_offset(adr, phase, offset);
4350   AllocateNode* alloc  = AllocateNode::Ideal_allocation(base, phase);
4351 
4352   if (offset == Type::OffsetBot) {
4353     return false; // cannot unalias unless there are precise offsets
4354   }
4355 
4356   if (alloc == NULL) {
4357      return false; // No allocation found
4358   }
4359 
4360   // Start search from Store node
4361   Node* mem = store->in(MemNode::Control);
4362   if (mem->is_Proj() && mem->in(0)->is_Initialize()) {
4363 
4364     InitializeNode* st_init = mem->in(0)->as_Initialize();
4365     AllocateNode*  st_alloc = st_init->allocation();
4366 
4367     // Make sure we are looking at the same allocation
4368     if (alloc == st_alloc) {
4369       return true;
4370     }
4371   }
4372 
4373   return false;
4374 }
4375 
4376 //
4377 // Update the card table and add card address to the queue
4378 //
4379 void GraphKit::g1_mark_card(IdealKit& ideal,
4380                             Node* card_adr,
4381                             Node* oop_store,
4382                             uint oop_alias_idx,
4383                             Node* index,
4384                             Node* index_adr,
4385                             Node* buffer,
4386                             const TypeFunc* tf) {
4387 
4388   Node* zero  = __ ConI(0);
4389   Node* zeroX = __ ConX(0);
4390   Node* no_base = __ top();
4391   BasicType card_bt = T_BYTE;
4392   // Smash zero into card. MUST BE ORDERED WRT TO STORE
4393   __ storeCM(__ ctrl(), card_adr, zero, oop_store, oop_alias_idx, card_bt, Compile::AliasIdxRaw);
4394 
4395   //  Now do the queue work
4396   __ if_then(index, BoolTest::ne, zeroX); {
4397 
4398     Node* next_index = _gvn.transform(new SubXNode(index, __ ConX(sizeof(intptr_t))));
4399     Node* log_addr = __ AddP(no_base, buffer, next_index);
4400 
4401     // Order, see storeCM.
4402     __ store(__ ctrl(), log_addr, card_adr, T_ADDRESS, Compile::AliasIdxRaw, MemNode::unordered);
4403     __ store(__ ctrl(), index_adr, next_index, TypeX_X->basic_type(), Compile::AliasIdxRaw, MemNode::unordered);
4404 
4405   } __ else_(); {
4406     __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_post), "g1_wb_post", card_adr, __ thread());
4407   } __ end_if();
4408 
4409 }
4410 
4411 void GraphKit::g1_write_barrier_post(Node* oop_store,
4412                                      Node* obj,
4413                                      Node* adr,
4414                                      uint alias_idx,
4415                                      Node* val,
4416                                      BasicType bt,
4417                                      bool use_precise) {
4418   // If we are writing a NULL then we need no post barrier
4419 
4420   if (val != NULL && val->is_Con() && val->bottom_type() == TypePtr::NULL_PTR) {
4421     // Must be NULL
4422     const Type* t = val->bottom_type();
4423     assert(t == Type::TOP || t == TypePtr::NULL_PTR, "must be NULL");
4424     // No post barrier if writing NULLx
4425     return;
4426   }
4427 
4428   if (use_ReduceInitialCardMarks() && obj == just_allocated_object(control())) {
4429     // We can skip marks on a freshly-allocated object in Eden.
4430     // Keep this code in sync with new_store_pre_barrier() in runtime.cpp.
4431     // That routine informs GC to take appropriate compensating steps,
4432     // upon a slow-path allocation, so as to make this card-mark
4433     // elision safe.
4434     return;
4435   }
4436 
4437   if (use_ReduceInitialCardMarks()
4438       && g1_can_remove_post_barrier(&_gvn, oop_store, adr)) {
4439     return;
4440   }
4441 
4442   if (!use_precise) {
4443     // All card marks for a (non-array) instance are in one place:
4444     adr = obj;
4445   }
4446   // (Else it's an array (or unknown), and we want more precise card marks.)
4447   assert(adr != NULL, "");
4448 
4449   IdealKit ideal(this, true);
4450 
4451   Node* tls = __ thread(); // ThreadLocalStorage
4452 
4453   Node* no_base = __ top();
4454   float likely  = PROB_LIKELY(0.999);
4455   float unlikely  = PROB_UNLIKELY(0.999);
4456   Node* young_card = __ ConI((jint)G1SATBCardTableModRefBS::g1_young_card_val());
4457   Node* dirty_card = __ ConI((jint)CardTableModRefBS::dirty_card_val());
4458   Node* zeroX = __ ConX(0);
4459 
4460   // Get the alias_index for raw card-mark memory
4461   const TypePtr* card_type = TypeRawPtr::BOTTOM;
4462 
4463   const TypeFunc *tf = OptoRuntime::g1_wb_post_Type();
4464 
4465   // Offsets into the thread
4466   const int index_offset  = in_bytes(JavaThread::dirty_card_queue_offset() +
4467                                      DirtyCardQueue::byte_offset_of_index());
4468   const int buffer_offset = in_bytes(JavaThread::dirty_card_queue_offset() +
4469                                      DirtyCardQueue::byte_offset_of_buf());
4470 
4471   // Pointers into the thread
4472 
4473   Node* buffer_adr = __ AddP(no_base, tls, __ ConX(buffer_offset));
4474   Node* index_adr =  __ AddP(no_base, tls, __ ConX(index_offset));
4475 
4476   // Now some values
4477   // Use ctrl to avoid hoisting these values past a safepoint, which could
4478   // potentially reset these fields in the JavaThread.
4479   Node* index  = __ load(__ ctrl(), index_adr, TypeX_X, TypeX_X->basic_type(), Compile::AliasIdxRaw);
4480   Node* buffer = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
4481 
4482   // Convert the store obj pointer to an int prior to doing math on it
4483   // Must use ctrl to prevent "integerized oop" existing across safepoint
4484   Node* cast =  __ CastPX(__ ctrl(), adr);
4485 
4486   // Divide pointer by card size
4487   Node* card_offset = __ URShiftX( cast, __ ConI(CardTableModRefBS::card_shift) );
4488 
4489   // Combine card table base and card offset
4490   Node* card_adr = __ AddP(no_base, byte_map_base_node(), card_offset );
4491 
4492   // If we know the value being stored does it cross regions?
4493 
4494   if (val != NULL) {
4495     // Does the store cause us to cross regions?
4496 
4497     // Should be able to do an unsigned compare of region_size instead of
4498     // and extra shift. Do we have an unsigned compare??
4499     // Node* region_size = __ ConI(1 << HeapRegion::LogOfHRGrainBytes);
4500     Node* xor_res =  __ URShiftX ( __ XorX( cast,  __ CastPX(__ ctrl(), val)), __ ConI(HeapRegion::LogOfHRGrainBytes));
4501 
4502     // if (xor_res == 0) same region so skip
4503     __ if_then(xor_res, BoolTest::ne, zeroX); {
4504 
4505       // No barrier if we are storing a NULL
4506       __ if_then(val, BoolTest::ne, null(), unlikely); {
4507 
4508         // Ok must mark the card if not already dirty
4509 
4510         // load the original value of the card
4511         Node* card_val = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
4512 
4513         __ if_then(card_val, BoolTest::ne, young_card); {
4514           sync_kit(ideal);
4515           // Use Op_MemBarVolatile to achieve the effect of a StoreLoad barrier.
4516           insert_mem_bar(Op_MemBarVolatile, oop_store);
4517           __ sync_kit(this);
4518 
4519           Node* card_val_reload = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
4520           __ if_then(card_val_reload, BoolTest::ne, dirty_card); {
4521             g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
4522           } __ end_if();
4523         } __ end_if();
4524       } __ end_if();
4525     } __ end_if();
4526   } else {
4527     // The Object.clone() intrinsic uses this path if !ReduceInitialCardMarks.
4528     // We don't need a barrier here if the destination is a newly allocated object
4529     // in Eden. Otherwise, GC verification breaks because we assume that cards in Eden
4530     // are set to 'g1_young_gen' (see G1SATBCardTableModRefBS::verify_g1_young_region()).
4531     assert(!use_ReduceInitialCardMarks(), "can only happen with card marking");
4532     Node* card_val = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
4533     __ if_then(card_val, BoolTest::ne, young_card); {
4534       g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
4535     } __ end_if();
4536   }
4537 
4538   // Final sync IdealKit and GraphKit.
4539   final_sync(ideal);
4540 }
4541 #undef __
4542 
4543 
4544 Node* GraphKit::load_String_length(Node* ctrl, Node* str) {
4545   Node* len = load_array_length(load_String_value(ctrl, str));
4546   Node* coder = load_String_coder(ctrl, str);
4547   // Divide length by 2 if coder is UTF16
4548   return _gvn.transform(new RShiftINode(len, coder));
4549 }
4550 
4551 Node* GraphKit::load_String_value(Node* ctrl, Node* str) {
4552   int value_offset = java_lang_String::value_offset_in_bytes();
4553   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4554                                                      false, NULL, Type::Offset(0));
4555   const TypePtr* value_field_type = string_type->add_offset(value_offset);
4556   const TypeAryPtr* value_type = TypeAryPtr::make(TypePtr::NotNull,
4557                                                   TypeAry::make(TypeInt::BYTE, TypeInt::POS),
4558                                                   ciTypeArrayKlass::make(T_BYTE), true, Type::Offset(0));
4559   int value_field_idx = C->get_alias_index(value_field_type);
4560   Node* load = make_load(ctrl, basic_plus_adr(str, str, value_offset),
4561                          value_type, T_OBJECT, value_field_idx, MemNode::unordered);
4562   // String.value field is known to be @Stable.
4563   if (UseImplicitStableValues) {
4564     load = cast_array_to_stable(load, value_type);
4565   }
4566   return load;
4567 }
4568 
4569 Node* GraphKit::load_String_coder(Node* ctrl, Node* str) {
4570   if (!CompactStrings) {
4571     return intcon(java_lang_String::CODER_UTF16);
4572   }
4573   int coder_offset = java_lang_String::coder_offset_in_bytes();
4574   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4575                                                      false, NULL, Type::Offset(0));
4576   const TypePtr* coder_field_type = string_type->add_offset(coder_offset);
4577   int coder_field_idx = C->get_alias_index(coder_field_type);
4578   return make_load(ctrl, basic_plus_adr(str, str, coder_offset),
4579                    TypeInt::BYTE, T_BYTE, coder_field_idx, MemNode::unordered);
4580 }
4581 
4582 void GraphKit::store_String_value(Node* ctrl, Node* str, Node* value) {
4583   int value_offset = java_lang_String::value_offset_in_bytes();
4584   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4585                                                      false, NULL, Type::Offset(0));
4586   const TypePtr* value_field_type = string_type->add_offset(value_offset);
4587   store_oop_to_object(ctrl, str,  basic_plus_adr(str, value_offset), value_field_type,
4588       value, TypeAryPtr::BYTES, T_OBJECT, MemNode::unordered);
4589 }
4590 
4591 void GraphKit::store_String_coder(Node* ctrl, Node* str, Node* value) {
4592   int coder_offset = java_lang_String::coder_offset_in_bytes();
4593   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4594                                                      false, NULL, Type::Offset(0));
4595   const TypePtr* coder_field_type = string_type->add_offset(coder_offset);
4596   int coder_field_idx = C->get_alias_index(coder_field_type);
4597   store_to_memory(ctrl, basic_plus_adr(str, coder_offset),
4598                   value, T_BYTE, coder_field_idx, MemNode::unordered);
4599 }
4600 
4601 // Capture src and dst memory state with a MergeMemNode
4602 Node* GraphKit::capture_memory(const TypePtr* src_type, const TypePtr* dst_type) {
4603   if (src_type == dst_type) {
4604     // Types are equal, we don't need a MergeMemNode
4605     return memory(src_type);
4606   }
4607   MergeMemNode* merge = MergeMemNode::make(map()->memory());
4608   record_for_igvn(merge); // fold it up later, if possible
4609   int src_idx = C->get_alias_index(src_type);
4610   int dst_idx = C->get_alias_index(dst_type);
4611   merge->set_memory_at(src_idx, memory(src_idx));
4612   merge->set_memory_at(dst_idx, memory(dst_idx));
4613   return merge;
4614 }
4615 
4616 Node* GraphKit::compress_string(Node* src, const TypeAryPtr* src_type, Node* dst, Node* count) {
4617   assert(Matcher::match_rule_supported(Op_StrCompressedCopy), "Intrinsic not supported");
4618   assert(src_type == TypeAryPtr::BYTES || src_type == TypeAryPtr::CHARS, "invalid source type");
4619   // If input and output memory types differ, capture both states to preserve
4620   // the dependency between preceding and subsequent loads/stores.
4621   // For example, the following program:
4622   //  StoreB
4623   //  compress_string
4624   //  LoadB
4625   // has this memory graph (use->def):
4626   //  LoadB -> compress_string -> CharMem
4627   //             ... -> StoreB -> ByteMem
4628   // The intrinsic hides the dependency between LoadB and StoreB, causing
4629   // the load to read from memory not containing the result of the StoreB.
4630   // The correct memory graph should look like this:
4631   //  LoadB -> compress_string -> MergeMem(CharMem, StoreB(ByteMem))
4632   Node* mem = capture_memory(src_type, TypeAryPtr::BYTES);
4633   StrCompressedCopyNode* str = new StrCompressedCopyNode(control(), mem, src, dst, count);
4634   Node* res_mem = _gvn.transform(new SCMemProjNode(str));
4635   set_memory(res_mem, TypeAryPtr::BYTES);
4636   return str;
4637 }
4638 
4639 void GraphKit::inflate_string(Node* src, Node* dst, const TypeAryPtr* dst_type, Node* count) {
4640   assert(Matcher::match_rule_supported(Op_StrInflatedCopy), "Intrinsic not supported");
4641   assert(dst_type == TypeAryPtr::BYTES || dst_type == TypeAryPtr::CHARS, "invalid dest type");
4642   // Capture src and dst memory (see comment in 'compress_string').
4643   Node* mem = capture_memory(TypeAryPtr::BYTES, dst_type);
4644   StrInflatedCopyNode* str = new StrInflatedCopyNode(control(), mem, src, dst, count);
4645   set_memory(_gvn.transform(str), dst_type);
4646 }
4647 
4648 void GraphKit::inflate_string_slow(Node* src, Node* dst, Node* start, Node* count) {
4649   /**
4650    * int i_char = start;
4651    * for (int i_byte = 0; i_byte < count; i_byte++) {
4652    *   dst[i_char++] = (char)(src[i_byte] & 0xff);
4653    * }
4654    */
4655   add_predicate();
4656   RegionNode* head = new RegionNode(3);
4657   head->init_req(1, control());
4658   gvn().set_type(head, Type::CONTROL);
4659   record_for_igvn(head);
4660 
4661   Node* i_byte = new PhiNode(head, TypeInt::INT);
4662   i_byte->init_req(1, intcon(0));
4663   gvn().set_type(i_byte, TypeInt::INT);
4664   record_for_igvn(i_byte);
4665 
4666   Node* i_char = new PhiNode(head, TypeInt::INT);
4667   i_char->init_req(1, start);
4668   gvn().set_type(i_char, TypeInt::INT);
4669   record_for_igvn(i_char);
4670 
4671   Node* mem = PhiNode::make(head, memory(TypeAryPtr::BYTES), Type::MEMORY, TypeAryPtr::BYTES);
4672   gvn().set_type(mem, Type::MEMORY);
4673   record_for_igvn(mem);
4674   set_control(head);
4675   set_memory(mem, TypeAryPtr::BYTES);
4676   Node* ch = load_array_element(control(), src, i_byte, TypeAryPtr::BYTES);
4677   Node* st = store_to_memory(control(), array_element_address(dst, i_char, T_BYTE),
4678                              AndI(ch, intcon(0xff)), T_CHAR, TypeAryPtr::BYTES, MemNode::unordered,
4679                              false, false, true /* mismatched */);
4680 
4681   IfNode* iff = create_and_map_if(head, Bool(CmpI(i_byte, count), BoolTest::lt), PROB_FAIR, COUNT_UNKNOWN);
4682   head->init_req(2, IfTrue(iff));
4683   mem->init_req(2, st);
4684   i_byte->init_req(2, AddI(i_byte, intcon(1)));
4685   i_char->init_req(2, AddI(i_char, intcon(2)));
4686 
4687   set_control(IfFalse(iff));
4688   set_memory(st, TypeAryPtr::BYTES);
4689 }
4690 
4691 Node* GraphKit::make_constant_from_field(ciField* field, Node* obj) {
4692   if (!field->is_constant()) {
4693     return NULL; // Field not marked as constant.
4694   }
4695   ciInstance* holder = NULL;
4696   if (!field->is_static()) {
4697     ciObject* const_oop = obj->bottom_type()->is_oopptr()->const_oop();
4698     if (const_oop != NULL && const_oop->is_instance()) {
4699       holder = const_oop->as_instance();
4700     }
4701   }
4702   const Type* con_type = Type::make_constant_from_field(field, holder, field->layout_type(),
4703                                                         /*is_unsigned_load=*/false);
4704   if (con_type != NULL) {
4705     Node* con = makecon(con_type);
4706     if (field->layout_type() == T_VALUETYPE) {
4707       // Load value type from constant oop
4708       con = ValueTypeNode::make_from_oop(this, con, field->type()->as_value_klass());
4709     }
4710     return con;
4711   }
4712   return NULL;
4713 }
4714 
4715 Node* GraphKit::cast_array_to_stable(Node* ary, const TypeAryPtr* ary_type) {
4716   // Reify the property as a CastPP node in Ideal graph to comply with monotonicity
4717   // assumption of CCP analysis.
4718   return _gvn.transform(new CastPPNode(ary, ary_type->cast_to_stable(true)));
4719 }