rev 5127 : 8023597: Optimize G1 barriers code for unsafe load_store
Summary: Avoid loading old values in G1 pre-barriers for inlined unsafe load_store nodes.

   1 /*
   2  * Copyright (c) 2001, 2012, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "compiler/compileLog.hpp"
  27 #include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp"
  28 #include "gc_implementation/g1/heapRegion.hpp"
  29 #include "gc_interface/collectedHeap.hpp"
  30 #include "memory/barrierSet.hpp"
  31 #include "memory/cardTableModRefBS.hpp"
  32 #include "opto/addnode.hpp"
  33 #include "opto/graphKit.hpp"
  34 #include "opto/idealKit.hpp"
  35 #include "opto/locknode.hpp"
  36 #include "opto/machnode.hpp"
  37 #include "opto/parse.hpp"
  38 #include "opto/rootnode.hpp"
  39 #include "opto/runtime.hpp"
  40 #include "runtime/deoptimization.hpp"
  41 #include "runtime/sharedRuntime.hpp"
  42 
  43 //----------------------------GraphKit-----------------------------------------
  44 // Main utility constructor.
  45 GraphKit::GraphKit(JVMState* jvms)
  46   : Phase(Phase::Parser),
  47     _env(C->env()),
  48     _gvn(*C->initial_gvn())
  49 {
  50   _exceptions = jvms->map()->next_exception();
  51   if (_exceptions != NULL)  jvms->map()->set_next_exception(NULL);
  52   set_jvms(jvms);
  53 }
  54 
  55 // Private constructor for parser.
  56 GraphKit::GraphKit()
  57   : Phase(Phase::Parser),
  58     _env(C->env()),
  59     _gvn(*C->initial_gvn())
  60 {
  61   _exceptions = NULL;
  62   set_map(NULL);
  63   debug_only(_sp = -99);
  64   debug_only(set_bci(-99));
  65 }
  66 
  67 
  68 
  69 //---------------------------clean_stack---------------------------------------
  70 // Clear away rubbish from the stack area of the JVM state.
  71 // This destroys any arguments that may be waiting on the stack.
  72 void GraphKit::clean_stack(int from_sp) {
  73   SafePointNode* map      = this->map();
  74   JVMState*      jvms     = this->jvms();
  75   int            stk_size = jvms->stk_size();
  76   int            stkoff   = jvms->stkoff();
  77   Node*          top      = this->top();
  78   for (int i = from_sp; i < stk_size; i++) {
  79     if (map->in(stkoff + i) != top) {
  80       map->set_req(stkoff + i, top);
  81     }
  82   }
  83 }
  84 
  85 
  86 //--------------------------------sync_jvms-----------------------------------
  87 // Make sure our current jvms agrees with our parse state.
  88 JVMState* GraphKit::sync_jvms() const {
  89   JVMState* jvms = this->jvms();
  90   jvms->set_bci(bci());       // Record the new bci in the JVMState
  91   jvms->set_sp(sp());         // Record the new sp in the JVMState
  92   assert(jvms_in_sync(), "jvms is now in sync");
  93   return jvms;
  94 }
  95 
  96 //--------------------------------sync_jvms_for_reexecute---------------------
  97 // Make sure our current jvms agrees with our parse state.  This version
  98 // uses the reexecute_sp for reexecuting bytecodes.
  99 JVMState* GraphKit::sync_jvms_for_reexecute() {
 100   JVMState* jvms = this->jvms();
 101   jvms->set_bci(bci());          // Record the new bci in the JVMState
 102   jvms->set_sp(reexecute_sp());  // Record the new sp in the JVMState
 103   return jvms;
 104 }
 105 
 106 #ifdef ASSERT
 107 bool GraphKit::jvms_in_sync() const {
 108   Parse* parse = is_Parse();
 109   if (parse == NULL) {
 110     if (bci() !=      jvms()->bci())          return false;
 111     if (sp()  != (int)jvms()->sp())           return false;
 112     return true;
 113   }
 114   if (jvms()->method() != parse->method())    return false;
 115   if (jvms()->bci()    != parse->bci())       return false;
 116   int jvms_sp = jvms()->sp();
 117   if (jvms_sp          != parse->sp())        return false;
 118   int jvms_depth = jvms()->depth();
 119   if (jvms_depth       != parse->depth())     return false;
 120   return true;
 121 }
 122 
 123 // Local helper checks for special internal merge points
 124 // used to accumulate and merge exception states.
 125 // They are marked by the region's in(0) edge being the map itself.
 126 // Such merge points must never "escape" into the parser at large,
 127 // until they have been handed to gvn.transform.
 128 static bool is_hidden_merge(Node* reg) {
 129   if (reg == NULL)  return false;
 130   if (reg->is_Phi()) {
 131     reg = reg->in(0);
 132     if (reg == NULL)  return false;
 133   }
 134   return reg->is_Region() && reg->in(0) != NULL && reg->in(0)->is_Root();
 135 }
 136 
 137 void GraphKit::verify_map() const {
 138   if (map() == NULL)  return;  // null map is OK
 139   assert(map()->req() <= jvms()->endoff(), "no extra garbage on map");
 140   assert(!map()->has_exceptions(),    "call add_exception_states_from 1st");
 141   assert(!is_hidden_merge(control()), "call use_exception_state, not set_map");
 142 }
 143 
 144 void GraphKit::verify_exception_state(SafePointNode* ex_map) {
 145   assert(ex_map->next_exception() == NULL, "not already part of a chain");
 146   assert(has_saved_ex_oop(ex_map), "every exception state has an ex_oop");
 147 }
 148 #endif
 149 
 150 //---------------------------stop_and_kill_map---------------------------------
 151 // Set _map to NULL, signalling a stop to further bytecode execution.
 152 // First smash the current map's control to a constant, to mark it dead.
 153 void GraphKit::stop_and_kill_map() {
 154   SafePointNode* dead_map = stop();
 155   if (dead_map != NULL) {
 156     dead_map->disconnect_inputs(NULL, C); // Mark the map as killed.
 157     assert(dead_map->is_killed(), "must be so marked");
 158   }
 159 }
 160 
 161 
 162 //--------------------------------stopped--------------------------------------
 163 // Tell if _map is NULL, or control is top.
 164 bool GraphKit::stopped() {
 165   if (map() == NULL)           return true;
 166   else if (control() == top()) return true;
 167   else                         return false;
 168 }
 169 
 170 
 171 //-----------------------------has_ex_handler----------------------------------
 172 // Tell if this method or any caller method has exception handlers.
 173 bool GraphKit::has_ex_handler() {
 174   for (JVMState* jvmsp = jvms(); jvmsp != NULL; jvmsp = jvmsp->caller()) {
 175     if (jvmsp->has_method() && jvmsp->method()->has_exception_handlers()) {
 176       return true;
 177     }
 178   }
 179   return false;
 180 }
 181 
 182 //------------------------------save_ex_oop------------------------------------
 183 // Save an exception without blowing stack contents or other JVM state.
 184 void GraphKit::set_saved_ex_oop(SafePointNode* ex_map, Node* ex_oop) {
 185   assert(!has_saved_ex_oop(ex_map), "clear ex-oop before setting again");
 186   ex_map->add_req(ex_oop);
 187   debug_only(verify_exception_state(ex_map));
 188 }
 189 
 190 inline static Node* common_saved_ex_oop(SafePointNode* ex_map, bool clear_it) {
 191   assert(GraphKit::has_saved_ex_oop(ex_map), "ex_oop must be there");
 192   Node* ex_oop = ex_map->in(ex_map->req()-1);
 193   if (clear_it)  ex_map->del_req(ex_map->req()-1);
 194   return ex_oop;
 195 }
 196 
 197 //-----------------------------saved_ex_oop------------------------------------
 198 // Recover a saved exception from its map.
 199 Node* GraphKit::saved_ex_oop(SafePointNode* ex_map) {
 200   return common_saved_ex_oop(ex_map, false);
 201 }
 202 
 203 //--------------------------clear_saved_ex_oop---------------------------------
 204 // Erase a previously saved exception from its map.
 205 Node* GraphKit::clear_saved_ex_oop(SafePointNode* ex_map) {
 206   return common_saved_ex_oop(ex_map, true);
 207 }
 208 
 209 #ifdef ASSERT
 210 //---------------------------has_saved_ex_oop----------------------------------
 211 // Erase a previously saved exception from its map.
 212 bool GraphKit::has_saved_ex_oop(SafePointNode* ex_map) {
 213   return ex_map->req() == ex_map->jvms()->endoff()+1;
 214 }
 215 #endif
 216 
 217 //-------------------------make_exception_state--------------------------------
 218 // Turn the current JVM state into an exception state, appending the ex_oop.
 219 SafePointNode* GraphKit::make_exception_state(Node* ex_oop) {
 220   sync_jvms();
 221   SafePointNode* ex_map = stop();  // do not manipulate this map any more
 222   set_saved_ex_oop(ex_map, ex_oop);
 223   return ex_map;
 224 }
 225 
 226 
 227 //--------------------------add_exception_state--------------------------------
 228 // Add an exception to my list of exceptions.
 229 void GraphKit::add_exception_state(SafePointNode* ex_map) {
 230   if (ex_map == NULL || ex_map->control() == top()) {
 231     return;
 232   }
 233 #ifdef ASSERT
 234   verify_exception_state(ex_map);
 235   if (has_exceptions()) {
 236     assert(ex_map->jvms()->same_calls_as(_exceptions->jvms()), "all collected exceptions must come from the same place");
 237   }
 238 #endif
 239 
 240   // If there is already an exception of exactly this type, merge with it.
 241   // In particular, null-checks and other low-level exceptions common up here.
 242   Node*       ex_oop  = saved_ex_oop(ex_map);
 243   const Type* ex_type = _gvn.type(ex_oop);
 244   if (ex_oop == top()) {
 245     // No action needed.
 246     return;
 247   }
 248   assert(ex_type->isa_instptr(), "exception must be an instance");
 249   for (SafePointNode* e2 = _exceptions; e2 != NULL; e2 = e2->next_exception()) {
 250     const Type* ex_type2 = _gvn.type(saved_ex_oop(e2));
 251     // We check sp also because call bytecodes can generate exceptions
 252     // both before and after arguments are popped!
 253     if (ex_type2 == ex_type
 254         && e2->_jvms->sp() == ex_map->_jvms->sp()) {
 255       combine_exception_states(ex_map, e2);
 256       return;
 257     }
 258   }
 259 
 260   // No pre-existing exception of the same type.  Chain it on the list.
 261   push_exception_state(ex_map);
 262 }
 263 
 264 //-----------------------add_exception_states_from-----------------------------
 265 void GraphKit::add_exception_states_from(JVMState* jvms) {
 266   SafePointNode* ex_map = jvms->map()->next_exception();
 267   if (ex_map != NULL) {
 268     jvms->map()->set_next_exception(NULL);
 269     for (SafePointNode* next_map; ex_map != NULL; ex_map = next_map) {
 270       next_map = ex_map->next_exception();
 271       ex_map->set_next_exception(NULL);
 272       add_exception_state(ex_map);
 273     }
 274   }
 275 }
 276 
 277 //-----------------------transfer_exceptions_into_jvms-------------------------
 278 JVMState* GraphKit::transfer_exceptions_into_jvms() {
 279   if (map() == NULL) {
 280     // We need a JVMS to carry the exceptions, but the map has gone away.
 281     // Create a scratch JVMS, cloned from any of the exception states...
 282     if (has_exceptions()) {
 283       _map = _exceptions;
 284       _map = clone_map();
 285       _map->set_next_exception(NULL);
 286       clear_saved_ex_oop(_map);
 287       debug_only(verify_map());
 288     } else {
 289       // ...or created from scratch
 290       JVMState* jvms = new (C) JVMState(_method, NULL);
 291       jvms->set_bci(_bci);
 292       jvms->set_sp(_sp);
 293       jvms->set_map(new (C) SafePointNode(TypeFunc::Parms, jvms));
 294       set_jvms(jvms);
 295       for (uint i = 0; i < map()->req(); i++)  map()->init_req(i, top());
 296       set_all_memory(top());
 297       while (map()->req() < jvms->endoff())  map()->add_req(top());
 298     }
 299     // (This is a kludge, in case you didn't notice.)
 300     set_control(top());
 301   }
 302   JVMState* jvms = sync_jvms();
 303   assert(!jvms->map()->has_exceptions(), "no exceptions on this map yet");
 304   jvms->map()->set_next_exception(_exceptions);
 305   _exceptions = NULL;   // done with this set of exceptions
 306   return jvms;
 307 }
 308 
 309 static inline void add_n_reqs(Node* dstphi, Node* srcphi) {
 310   assert(is_hidden_merge(dstphi), "must be a special merge node");
 311   assert(is_hidden_merge(srcphi), "must be a special merge node");
 312   uint limit = srcphi->req();
 313   for (uint i = PhiNode::Input; i < limit; i++) {
 314     dstphi->add_req(srcphi->in(i));
 315   }
 316 }
 317 static inline void add_one_req(Node* dstphi, Node* src) {
 318   assert(is_hidden_merge(dstphi), "must be a special merge node");
 319   assert(!is_hidden_merge(src), "must not be a special merge node");
 320   dstphi->add_req(src);
 321 }
 322 
 323 //-----------------------combine_exception_states------------------------------
 324 // This helper function combines exception states by building phis on a
 325 // specially marked state-merging region.  These regions and phis are
 326 // untransformed, and can build up gradually.  The region is marked by
 327 // having a control input of its exception map, rather than NULL.  Such
 328 // regions do not appear except in this function, and in use_exception_state.
 329 void GraphKit::combine_exception_states(SafePointNode* ex_map, SafePointNode* phi_map) {
 330   if (failing())  return;  // dying anyway...
 331   JVMState* ex_jvms = ex_map->_jvms;
 332   assert(ex_jvms->same_calls_as(phi_map->_jvms), "consistent call chains");
 333   assert(ex_jvms->stkoff() == phi_map->_jvms->stkoff(), "matching locals");
 334   assert(ex_jvms->sp() == phi_map->_jvms->sp(), "matching stack sizes");
 335   assert(ex_jvms->monoff() == phi_map->_jvms->monoff(), "matching JVMS");
 336   assert(ex_jvms->scloff() == phi_map->_jvms->scloff(), "matching scalar replaced objects");
 337   assert(ex_map->req() == phi_map->req(), "matching maps");
 338   uint tos = ex_jvms->stkoff() + ex_jvms->sp();
 339   Node*         hidden_merge_mark = root();
 340   Node*         region  = phi_map->control();
 341   MergeMemNode* phi_mem = phi_map->merged_memory();
 342   MergeMemNode* ex_mem  = ex_map->merged_memory();
 343   if (region->in(0) != hidden_merge_mark) {
 344     // The control input is not (yet) a specially-marked region in phi_map.
 345     // Make it so, and build some phis.
 346     region = new (C) RegionNode(2);
 347     _gvn.set_type(region, Type::CONTROL);
 348     region->set_req(0, hidden_merge_mark);  // marks an internal ex-state
 349     region->init_req(1, phi_map->control());
 350     phi_map->set_control(region);
 351     Node* io_phi = PhiNode::make(region, phi_map->i_o(), Type::ABIO);
 352     record_for_igvn(io_phi);
 353     _gvn.set_type(io_phi, Type::ABIO);
 354     phi_map->set_i_o(io_phi);
 355     for (MergeMemStream mms(phi_mem); mms.next_non_empty(); ) {
 356       Node* m = mms.memory();
 357       Node* m_phi = PhiNode::make(region, m, Type::MEMORY, mms.adr_type(C));
 358       record_for_igvn(m_phi);
 359       _gvn.set_type(m_phi, Type::MEMORY);
 360       mms.set_memory(m_phi);
 361     }
 362   }
 363 
 364   // Either or both of phi_map and ex_map might already be converted into phis.
 365   Node* ex_control = ex_map->control();
 366   // if there is special marking on ex_map also, we add multiple edges from src
 367   bool add_multiple = (ex_control->in(0) == hidden_merge_mark);
 368   // how wide was the destination phi_map, originally?
 369   uint orig_width = region->req();
 370 
 371   if (add_multiple) {
 372     add_n_reqs(region, ex_control);
 373     add_n_reqs(phi_map->i_o(), ex_map->i_o());
 374   } else {
 375     // ex_map has no merges, so we just add single edges everywhere
 376     add_one_req(region, ex_control);
 377     add_one_req(phi_map->i_o(), ex_map->i_o());
 378   }
 379   for (MergeMemStream mms(phi_mem, ex_mem); mms.next_non_empty2(); ) {
 380     if (mms.is_empty()) {
 381       // get a copy of the base memory, and patch some inputs into it
 382       const TypePtr* adr_type = mms.adr_type(C);
 383       Node* phi = mms.force_memory()->as_Phi()->slice_memory(adr_type);
 384       assert(phi->as_Phi()->region() == mms.base_memory()->in(0), "");
 385       mms.set_memory(phi);
 386       // Prepare to append interesting stuff onto the newly sliced phi:
 387       while (phi->req() > orig_width)  phi->del_req(phi->req()-1);
 388     }
 389     // Append stuff from ex_map:
 390     if (add_multiple) {
 391       add_n_reqs(mms.memory(), mms.memory2());
 392     } else {
 393       add_one_req(mms.memory(), mms.memory2());
 394     }
 395   }
 396   uint limit = ex_map->req();
 397   for (uint i = TypeFunc::Parms; i < limit; i++) {
 398     // Skip everything in the JVMS after tos.  (The ex_oop follows.)
 399     if (i == tos)  i = ex_jvms->monoff();
 400     Node* src = ex_map->in(i);
 401     Node* dst = phi_map->in(i);
 402     if (src != dst) {
 403       PhiNode* phi;
 404       if (dst->in(0) != region) {
 405         dst = phi = PhiNode::make(region, dst, _gvn.type(dst));
 406         record_for_igvn(phi);
 407         _gvn.set_type(phi, phi->type());
 408         phi_map->set_req(i, dst);
 409         // Prepare to append interesting stuff onto the new phi:
 410         while (dst->req() > orig_width)  dst->del_req(dst->req()-1);
 411       } else {
 412         assert(dst->is_Phi(), "nobody else uses a hidden region");
 413         phi = dst->as_Phi();
 414       }
 415       if (add_multiple && src->in(0) == ex_control) {
 416         // Both are phis.
 417         add_n_reqs(dst, src);
 418       } else {
 419         while (dst->req() < region->req())  add_one_req(dst, src);
 420       }
 421       const Type* srctype = _gvn.type(src);
 422       if (phi->type() != srctype) {
 423         const Type* dsttype = phi->type()->meet(srctype);
 424         if (phi->type() != dsttype) {
 425           phi->set_type(dsttype);
 426           _gvn.set_type(phi, dsttype);
 427         }
 428       }
 429     }
 430   }
 431 }
 432 
 433 //--------------------------use_exception_state--------------------------------
 434 Node* GraphKit::use_exception_state(SafePointNode* phi_map) {
 435   if (failing()) { stop(); return top(); }
 436   Node* region = phi_map->control();
 437   Node* hidden_merge_mark = root();
 438   assert(phi_map->jvms()->map() == phi_map, "sanity: 1-1 relation");
 439   Node* ex_oop = clear_saved_ex_oop(phi_map);
 440   if (region->in(0) == hidden_merge_mark) {
 441     // Special marking for internal ex-states.  Process the phis now.
 442     region->set_req(0, region);  // now it's an ordinary region
 443     set_jvms(phi_map->jvms());   // ...so now we can use it as a map
 444     // Note: Setting the jvms also sets the bci and sp.
 445     set_control(_gvn.transform(region));
 446     uint tos = jvms()->stkoff() + sp();
 447     for (uint i = 1; i < tos; i++) {
 448       Node* x = phi_map->in(i);
 449       if (x->in(0) == region) {
 450         assert(x->is_Phi(), "expected a special phi");
 451         phi_map->set_req(i, _gvn.transform(x));
 452       }
 453     }
 454     for (MergeMemStream mms(merged_memory()); mms.next_non_empty(); ) {
 455       Node* x = mms.memory();
 456       if (x->in(0) == region) {
 457         assert(x->is_Phi(), "nobody else uses a hidden region");
 458         mms.set_memory(_gvn.transform(x));
 459       }
 460     }
 461     if (ex_oop->in(0) == region) {
 462       assert(ex_oop->is_Phi(), "expected a special phi");
 463       ex_oop = _gvn.transform(ex_oop);
 464     }
 465   } else {
 466     set_jvms(phi_map->jvms());
 467   }
 468 
 469   assert(!is_hidden_merge(phi_map->control()), "hidden ex. states cleared");
 470   assert(!is_hidden_merge(phi_map->i_o()), "hidden ex. states cleared");
 471   return ex_oop;
 472 }
 473 
 474 //---------------------------------java_bc-------------------------------------
 475 Bytecodes::Code GraphKit::java_bc() const {
 476   ciMethod* method = this->method();
 477   int       bci    = this->bci();
 478   if (method != NULL && bci != InvocationEntryBci)
 479     return method->java_code_at_bci(bci);
 480   else
 481     return Bytecodes::_illegal;
 482 }
 483 
 484 void GraphKit::uncommon_trap_if_should_post_on_exceptions(Deoptimization::DeoptReason reason,
 485                                                           bool must_throw) {
 486     // if the exception capability is set, then we will generate code
 487     // to check the JavaThread.should_post_on_exceptions flag to see
 488     // if we actually need to report exception events (for this
 489     // thread).  If we don't need to report exception events, we will
 490     // take the normal fast path provided by add_exception_events.  If
 491     // exception event reporting is enabled for this thread, we will
 492     // take the uncommon_trap in the BuildCutout below.
 493 
 494     // first must access the should_post_on_exceptions_flag in this thread's JavaThread
 495     Node* jthread = _gvn.transform(new (C) ThreadLocalNode());
 496     Node* adr = basic_plus_adr(top(), jthread, in_bytes(JavaThread::should_post_on_exceptions_flag_offset()));
 497     Node* should_post_flag = make_load(control(), adr, TypeInt::INT, T_INT, Compile::AliasIdxRaw, false);
 498 
 499     // Test the should_post_on_exceptions_flag vs. 0
 500     Node* chk = _gvn.transform( new (C) CmpINode(should_post_flag, intcon(0)) );
 501     Node* tst = _gvn.transform( new (C) BoolNode(chk, BoolTest::eq) );
 502 
 503     // Branch to slow_path if should_post_on_exceptions_flag was true
 504     { BuildCutout unless(this, tst, PROB_MAX);
 505       // Do not try anything fancy if we're notifying the VM on every throw.
 506       // Cf. case Bytecodes::_athrow in parse2.cpp.
 507       uncommon_trap(reason, Deoptimization::Action_none,
 508                     (ciKlass*)NULL, (char*)NULL, must_throw);
 509     }
 510 
 511 }
 512 
 513 //------------------------------builtin_throw----------------------------------
 514 void GraphKit::builtin_throw(Deoptimization::DeoptReason reason, Node* arg) {
 515   bool must_throw = true;
 516 
 517   if (env()->jvmti_can_post_on_exceptions()) {
 518     // check if we must post exception events, take uncommon trap if so
 519     uncommon_trap_if_should_post_on_exceptions(reason, must_throw);
 520     // here if should_post_on_exceptions is false
 521     // continue on with the normal codegen
 522   }
 523 
 524   // If this particular condition has not yet happened at this
 525   // bytecode, then use the uncommon trap mechanism, and allow for
 526   // a future recompilation if several traps occur here.
 527   // If the throw is hot, try to use a more complicated inline mechanism
 528   // which keeps execution inside the compiled code.
 529   bool treat_throw_as_hot = false;
 530   ciMethodData* md = method()->method_data();
 531 
 532   if (ProfileTraps) {
 533     if (too_many_traps(reason)) {
 534       treat_throw_as_hot = true;
 535     }
 536     // (If there is no MDO at all, assume it is early in
 537     // execution, and that any deopts are part of the
 538     // startup transient, and don't need to be remembered.)
 539 
 540     // Also, if there is a local exception handler, treat all throws
 541     // as hot if there has been at least one in this method.
 542     if (C->trap_count(reason) != 0
 543         && method()->method_data()->trap_count(reason) != 0
 544         && has_ex_handler()) {
 545         treat_throw_as_hot = true;
 546     }
 547   }
 548 
 549   // If this throw happens frequently, an uncommon trap might cause
 550   // a performance pothole.  If there is a local exception handler,
 551   // and if this particular bytecode appears to be deoptimizing often,
 552   // let us handle the throw inline, with a preconstructed instance.
 553   // Note:   If the deopt count has blown up, the uncommon trap
 554   // runtime is going to flush this nmethod, not matter what.
 555   if (treat_throw_as_hot
 556       && (!StackTraceInThrowable || OmitStackTraceInFastThrow)) {
 557     // If the throw is local, we use a pre-existing instance and
 558     // punt on the backtrace.  This would lead to a missing backtrace
 559     // (a repeat of 4292742) if the backtrace object is ever asked
 560     // for its backtrace.
 561     // Fixing this remaining case of 4292742 requires some flavor of
 562     // escape analysis.  Leave that for the future.
 563     ciInstance* ex_obj = NULL;
 564     switch (reason) {
 565     case Deoptimization::Reason_null_check:
 566       ex_obj = env()->NullPointerException_instance();
 567       break;
 568     case Deoptimization::Reason_div0_check:
 569       ex_obj = env()->ArithmeticException_instance();
 570       break;
 571     case Deoptimization::Reason_range_check:
 572       ex_obj = env()->ArrayIndexOutOfBoundsException_instance();
 573       break;
 574     case Deoptimization::Reason_class_check:
 575       if (java_bc() == Bytecodes::_aastore) {
 576         ex_obj = env()->ArrayStoreException_instance();
 577       } else {
 578         ex_obj = env()->ClassCastException_instance();
 579       }
 580       break;
 581     }
 582     if (failing()) { stop(); return; }  // exception allocation might fail
 583     if (ex_obj != NULL) {
 584       // Cheat with a preallocated exception object.
 585       if (C->log() != NULL)
 586         C->log()->elem("hot_throw preallocated='1' reason='%s'",
 587                        Deoptimization::trap_reason_name(reason));
 588       const TypeInstPtr* ex_con  = TypeInstPtr::make(ex_obj);
 589       Node*              ex_node = _gvn.transform( ConNode::make(C, ex_con) );
 590 
 591       // Clear the detail message of the preallocated exception object.
 592       // Weblogic sometimes mutates the detail message of exceptions
 593       // using reflection.
 594       int offset = java_lang_Throwable::get_detailMessage_offset();
 595       const TypePtr* adr_typ = ex_con->add_offset(offset);
 596 
 597       Node *adr = basic_plus_adr(ex_node, ex_node, offset);
 598       const TypeOopPtr* val_type = TypeOopPtr::make_from_klass(env()->String_klass());
 599       Node *store = store_oop_to_object(control(), ex_node, adr, adr_typ, null(), val_type, T_OBJECT);
 600 
 601       add_exception_state(make_exception_state(ex_node));
 602       return;
 603     }
 604   }
 605 
 606   // %%% Maybe add entry to OptoRuntime which directly throws the exc.?
 607   // It won't be much cheaper than bailing to the interp., since we'll
 608   // have to pass up all the debug-info, and the runtime will have to
 609   // create the stack trace.
 610 
 611   // Usual case:  Bail to interpreter.
 612   // Reserve the right to recompile if we haven't seen anything yet.
 613 
 614   Deoptimization::DeoptAction action = Deoptimization::Action_maybe_recompile;
 615   if (treat_throw_as_hot
 616       && (method()->method_data()->trap_recompiled_at(bci())
 617           || C->too_many_traps(reason))) {
 618     // We cannot afford to take more traps here.  Suffer in the interpreter.
 619     if (C->log() != NULL)
 620       C->log()->elem("hot_throw preallocated='0' reason='%s' mcount='%d'",
 621                      Deoptimization::trap_reason_name(reason),
 622                      C->trap_count(reason));
 623     action = Deoptimization::Action_none;
 624   }
 625 
 626   // "must_throw" prunes the JVM state to include only the stack, if there
 627   // are no local exception handlers.  This should cut down on register
 628   // allocation time and code size, by drastically reducing the number
 629   // of in-edges on the call to the uncommon trap.
 630 
 631   uncommon_trap(reason, action, (ciKlass*)NULL, (char*)NULL, must_throw);
 632 }
 633 
 634 
 635 //----------------------------PreserveJVMState---------------------------------
 636 PreserveJVMState::PreserveJVMState(GraphKit* kit, bool clone_map) {
 637   debug_only(kit->verify_map());
 638   _kit    = kit;
 639   _map    = kit->map();   // preserve the map
 640   _sp     = kit->sp();
 641   kit->set_map(clone_map ? kit->clone_map() : NULL);
 642 #ifdef ASSERT
 643   _bci    = kit->bci();
 644   Parse* parser = kit->is_Parse();
 645   int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo();
 646   _block  = block;
 647 #endif
 648 }
 649 PreserveJVMState::~PreserveJVMState() {
 650   GraphKit* kit = _kit;
 651 #ifdef ASSERT
 652   assert(kit->bci() == _bci, "bci must not shift");
 653   Parse* parser = kit->is_Parse();
 654   int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo();
 655   assert(block == _block,    "block must not shift");
 656 #endif
 657   kit->set_map(_map);
 658   kit->set_sp(_sp);
 659 }
 660 
 661 
 662 //-----------------------------BuildCutout-------------------------------------
 663 BuildCutout::BuildCutout(GraphKit* kit, Node* p, float prob, float cnt)
 664   : PreserveJVMState(kit)
 665 {
 666   assert(p->is_Con() || p->is_Bool(), "test must be a bool");
 667   SafePointNode* outer_map = _map;   // preserved map is caller's
 668   SafePointNode* inner_map = kit->map();
 669   IfNode* iff = kit->create_and_map_if(outer_map->control(), p, prob, cnt);
 670   outer_map->set_control(kit->gvn().transform( new (kit->C) IfTrueNode(iff) ));
 671   inner_map->set_control(kit->gvn().transform( new (kit->C) IfFalseNode(iff) ));
 672 }
 673 BuildCutout::~BuildCutout() {
 674   GraphKit* kit = _kit;
 675   assert(kit->stopped(), "cutout code must stop, throw, return, etc.");
 676 }
 677 
 678 //---------------------------PreserveReexecuteState----------------------------
 679 PreserveReexecuteState::PreserveReexecuteState(GraphKit* kit) {
 680   assert(!kit->stopped(), "must call stopped() before");
 681   _kit    =    kit;
 682   _sp     =    kit->sp();
 683   _reexecute = kit->jvms()->_reexecute;
 684 }
 685 PreserveReexecuteState::~PreserveReexecuteState() {
 686   if (_kit->stopped()) return;
 687   _kit->jvms()->_reexecute = _reexecute;
 688   _kit->set_sp(_sp);
 689 }
 690 
 691 //------------------------------clone_map--------------------------------------
 692 // Implementation of PreserveJVMState
 693 //
 694 // Only clone_map(...) here. If this function is only used in the
 695 // PreserveJVMState class we may want to get rid of this extra
 696 // function eventually and do it all there.
 697 
 698 SafePointNode* GraphKit::clone_map() {
 699   if (map() == NULL)  return NULL;
 700 
 701   // Clone the memory edge first
 702   Node* mem = MergeMemNode::make(C, map()->memory());
 703   gvn().set_type_bottom(mem);
 704 
 705   SafePointNode *clonemap = (SafePointNode*)map()->clone();
 706   JVMState* jvms = this->jvms();
 707   JVMState* clonejvms = jvms->clone_shallow(C);
 708   clonemap->set_memory(mem);
 709   clonemap->set_jvms(clonejvms);
 710   clonejvms->set_map(clonemap);
 711   record_for_igvn(clonemap);
 712   gvn().set_type_bottom(clonemap);
 713   return clonemap;
 714 }
 715 
 716 
 717 //-----------------------------set_map_clone-----------------------------------
 718 void GraphKit::set_map_clone(SafePointNode* m) {
 719   _map = m;
 720   _map = clone_map();
 721   _map->set_next_exception(NULL);
 722   debug_only(verify_map());
 723 }
 724 
 725 
 726 //----------------------------kill_dead_locals---------------------------------
 727 // Detect any locals which are known to be dead, and force them to top.
 728 void GraphKit::kill_dead_locals() {
 729   // Consult the liveness information for the locals.  If any
 730   // of them are unused, then they can be replaced by top().  This
 731   // should help register allocation time and cut down on the size
 732   // of the deoptimization information.
 733 
 734   // This call is made from many of the bytecode handling
 735   // subroutines called from the Big Switch in do_one_bytecode.
 736   // Every bytecode which might include a slow path is responsible
 737   // for killing its dead locals.  The more consistent we
 738   // are about killing deads, the fewer useless phis will be
 739   // constructed for them at various merge points.
 740 
 741   // bci can be -1 (InvocationEntryBci).  We return the entry
 742   // liveness for the method.
 743 
 744   if (method() == NULL || method()->code_size() == 0) {
 745     // We are building a graph for a call to a native method.
 746     // All locals are live.
 747     return;
 748   }
 749 
 750   ResourceMark rm;
 751 
 752   // Consult the liveness information for the locals.  If any
 753   // of them are unused, then they can be replaced by top().  This
 754   // should help register allocation time and cut down on the size
 755   // of the deoptimization information.
 756   MethodLivenessResult live_locals = method()->liveness_at_bci(bci());
 757 
 758   int len = (int)live_locals.size();
 759   assert(len <= jvms()->loc_size(), "too many live locals");
 760   for (int local = 0; local < len; local++) {
 761     if (!live_locals.at(local)) {
 762       set_local(local, top());
 763     }
 764   }
 765 }
 766 
 767 #ifdef ASSERT
 768 //-------------------------dead_locals_are_killed------------------------------
 769 // Return true if all dead locals are set to top in the map.
 770 // Used to assert "clean" debug info at various points.
 771 bool GraphKit::dead_locals_are_killed() {
 772   if (method() == NULL || method()->code_size() == 0) {
 773     // No locals need to be dead, so all is as it should be.
 774     return true;
 775   }
 776 
 777   // Make sure somebody called kill_dead_locals upstream.
 778   ResourceMark rm;
 779   for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) {
 780     if (jvms->loc_size() == 0)  continue;  // no locals to consult
 781     SafePointNode* map = jvms->map();
 782     ciMethod* method = jvms->method();
 783     int       bci    = jvms->bci();
 784     if (jvms == this->jvms()) {
 785       bci = this->bci();  // it might not yet be synched
 786     }
 787     MethodLivenessResult live_locals = method->liveness_at_bci(bci);
 788     int len = (int)live_locals.size();
 789     if (!live_locals.is_valid() || len == 0)
 790       // This method is trivial, or is poisoned by a breakpoint.
 791       return true;
 792     assert(len == jvms->loc_size(), "live map consistent with locals map");
 793     for (int local = 0; local < len; local++) {
 794       if (!live_locals.at(local) && map->local(jvms, local) != top()) {
 795         if (PrintMiscellaneous && (Verbose || WizardMode)) {
 796           tty->print_cr("Zombie local %d: ", local);
 797           jvms->dump();
 798         }
 799         return false;
 800       }
 801     }
 802   }
 803   return true;
 804 }
 805 
 806 #endif //ASSERT
 807 
 808 // Helper function for enforcing certain bytecodes to reexecute if
 809 // deoptimization happens
 810 static bool should_reexecute_implied_by_bytecode(JVMState *jvms, bool is_anewarray) {
 811   ciMethod* cur_method = jvms->method();
 812   int       cur_bci   = jvms->bci();
 813   if (cur_method != NULL && cur_bci != InvocationEntryBci) {
 814     Bytecodes::Code code = cur_method->java_code_at_bci(cur_bci);
 815     return Interpreter::bytecode_should_reexecute(code) ||
 816            is_anewarray && code == Bytecodes::_multianewarray;
 817     // Reexecute _multianewarray bytecode which was replaced with
 818     // sequence of [a]newarray. See Parse::do_multianewarray().
 819     //
 820     // Note: interpreter should not have it set since this optimization
 821     // is limited by dimensions and guarded by flag so in some cases
 822     // multianewarray() runtime calls will be generated and
 823     // the bytecode should not be reexecutes (stack will not be reset).
 824   } else
 825     return false;
 826 }
 827 
 828 // Helper function for adding JVMState and debug information to node
 829 void GraphKit::add_safepoint_edges(SafePointNode* call, bool must_throw) {
 830   // Add the safepoint edges to the call (or other safepoint).
 831 
 832   // Make sure dead locals are set to top.  This
 833   // should help register allocation time and cut down on the size
 834   // of the deoptimization information.
 835   assert(dead_locals_are_killed(), "garbage in debug info before safepoint");
 836 
 837   // Walk the inline list to fill in the correct set of JVMState's
 838   // Also fill in the associated edges for each JVMState.
 839 
 840   // If the bytecode needs to be reexecuted we need to put
 841   // the arguments back on the stack.
 842   const bool should_reexecute = jvms()->should_reexecute();
 843   JVMState* youngest_jvms = should_reexecute ? sync_jvms_for_reexecute() : sync_jvms();
 844 
 845   // NOTE: set_bci (called from sync_jvms) might reset the reexecute bit to
 846   // undefined if the bci is different.  This is normal for Parse but it
 847   // should not happen for LibraryCallKit because only one bci is processed.
 848   assert(!is_LibraryCallKit() || (jvms()->should_reexecute() == should_reexecute),
 849          "in LibraryCallKit the reexecute bit should not change");
 850 
 851   // If we are guaranteed to throw, we can prune everything but the
 852   // input to the current bytecode.
 853   bool can_prune_locals = false;
 854   uint stack_slots_not_pruned = 0;
 855   int inputs = 0, depth = 0;
 856   if (must_throw) {
 857     assert(method() == youngest_jvms->method(), "sanity");
 858     if (compute_stack_effects(inputs, depth)) {
 859       can_prune_locals = true;
 860       stack_slots_not_pruned = inputs;
 861     }
 862   }
 863 
 864   if (env()->jvmti_can_access_local_variables()) {
 865     // At any safepoint, this method can get breakpointed, which would
 866     // then require an immediate deoptimization.
 867     can_prune_locals = false;  // do not prune locals
 868     stack_slots_not_pruned = 0;
 869   }
 870 
 871   // do not scribble on the input jvms
 872   JVMState* out_jvms = youngest_jvms->clone_deep(C);
 873   call->set_jvms(out_jvms); // Start jvms list for call node
 874 
 875   // For a known set of bytecodes, the interpreter should reexecute them if
 876   // deoptimization happens. We set the reexecute state for them here
 877   if (out_jvms->is_reexecute_undefined() && //don't change if already specified
 878       should_reexecute_implied_by_bytecode(out_jvms, call->is_AllocateArray())) {
 879     out_jvms->set_should_reexecute(true); //NOTE: youngest_jvms not changed
 880   }
 881 
 882   // Presize the call:
 883   DEBUG_ONLY(uint non_debug_edges = call->req());
 884   call->add_req_batch(top(), youngest_jvms->debug_depth());
 885   assert(call->req() == non_debug_edges + youngest_jvms->debug_depth(), "");
 886 
 887   // Set up edges so that the call looks like this:
 888   //  Call [state:] ctl io mem fptr retadr
 889   //       [parms:] parm0 ... parmN
 890   //       [root:]  loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN
 891   //    [...mid:]   loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN [...]
 892   //       [young:] loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN
 893   // Note that caller debug info precedes callee debug info.
 894 
 895   // Fill pointer walks backwards from "young:" to "root:" in the diagram above:
 896   uint debug_ptr = call->req();
 897 
 898   // Loop over the map input edges associated with jvms, add them
 899   // to the call node, & reset all offsets to match call node array.
 900   for (JVMState* in_jvms = youngest_jvms; in_jvms != NULL; ) {
 901     uint debug_end   = debug_ptr;
 902     uint debug_start = debug_ptr - in_jvms->debug_size();
 903     debug_ptr = debug_start;  // back up the ptr
 904 
 905     uint p = debug_start;  // walks forward in [debug_start, debug_end)
 906     uint j, k, l;
 907     SafePointNode* in_map = in_jvms->map();
 908     out_jvms->set_map(call);
 909 
 910     if (can_prune_locals) {
 911       assert(in_jvms->method() == out_jvms->method(), "sanity");
 912       // If the current throw can reach an exception handler in this JVMS,
 913       // then we must keep everything live that can reach that handler.
 914       // As a quick and dirty approximation, we look for any handlers at all.
 915       if (in_jvms->method()->has_exception_handlers()) {
 916         can_prune_locals = false;
 917       }
 918     }
 919 
 920     // Add the Locals
 921     k = in_jvms->locoff();
 922     l = in_jvms->loc_size();
 923     out_jvms->set_locoff(p);
 924     if (!can_prune_locals) {
 925       for (j = 0; j < l; j++)
 926         call->set_req(p++, in_map->in(k+j));
 927     } else {
 928       p += l;  // already set to top above by add_req_batch
 929     }
 930 
 931     // Add the Expression Stack
 932     k = in_jvms->stkoff();
 933     l = in_jvms->sp();
 934     out_jvms->set_stkoff(p);
 935     if (!can_prune_locals) {
 936       for (j = 0; j < l; j++)
 937         call->set_req(p++, in_map->in(k+j));
 938     } else if (can_prune_locals && stack_slots_not_pruned != 0) {
 939       // Divide stack into {S0,...,S1}, where S0 is set to top.
 940       uint s1 = stack_slots_not_pruned;
 941       stack_slots_not_pruned = 0;  // for next iteration
 942       if (s1 > l)  s1 = l;
 943       uint s0 = l - s1;
 944       p += s0;  // skip the tops preinstalled by add_req_batch
 945       for (j = s0; 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 Monitors
 952     k = in_jvms->monoff();
 953     l = in_jvms->mon_size();
 954     out_jvms->set_monoff(p);
 955     for (j = 0; j < l; j++)
 956       call->set_req(p++, in_map->in(k+j));
 957 
 958     // Copy any scalar object fields.
 959     k = in_jvms->scloff();
 960     l = in_jvms->scl_size();
 961     out_jvms->set_scloff(p);
 962     for (j = 0; j < l; j++)
 963       call->set_req(p++, in_map->in(k+j));
 964 
 965     // Finish the new jvms.
 966     out_jvms->set_endoff(p);
 967 
 968     assert(out_jvms->endoff()     == debug_end,             "fill ptr must match");
 969     assert(out_jvms->depth()      == in_jvms->depth(),      "depth must match");
 970     assert(out_jvms->loc_size()   == in_jvms->loc_size(),   "size must match");
 971     assert(out_jvms->mon_size()   == in_jvms->mon_size(),   "size must match");
 972     assert(out_jvms->scl_size()   == in_jvms->scl_size(),   "size must match");
 973     assert(out_jvms->debug_size() == in_jvms->debug_size(), "size must match");
 974 
 975     // Update the two tail pointers in parallel.
 976     out_jvms = out_jvms->caller();
 977     in_jvms  = in_jvms->caller();
 978   }
 979 
 980   assert(debug_ptr == non_debug_edges, "debug info must fit exactly");
 981 
 982   // Test the correctness of JVMState::debug_xxx accessors:
 983   assert(call->jvms()->debug_start() == non_debug_edges, "");
 984   assert(call->jvms()->debug_end()   == call->req(), "");
 985   assert(call->jvms()->debug_depth() == call->req() - non_debug_edges, "");
 986 }
 987 
 988 bool GraphKit::compute_stack_effects(int& inputs, int& depth) {
 989   Bytecodes::Code code = java_bc();
 990   if (code == Bytecodes::_wide) {
 991     code = method()->java_code_at_bci(bci() + 1);
 992   }
 993 
 994   BasicType rtype = T_ILLEGAL;
 995   int       rsize = 0;
 996 
 997   if (code != Bytecodes::_illegal) {
 998     depth = Bytecodes::depth(code); // checkcast=0, athrow=-1
 999     rtype = Bytecodes::result_type(code); // checkcast=P, athrow=V
1000     if (rtype < T_CONFLICT)
1001       rsize = type2size[rtype];
1002   }
1003 
1004   switch (code) {
1005   case Bytecodes::_illegal:
1006     return false;
1007 
1008   case Bytecodes::_ldc:
1009   case Bytecodes::_ldc_w:
1010   case Bytecodes::_ldc2_w:
1011     inputs = 0;
1012     break;
1013 
1014   case Bytecodes::_dup:         inputs = 1;  break;
1015   case Bytecodes::_dup_x1:      inputs = 2;  break;
1016   case Bytecodes::_dup_x2:      inputs = 3;  break;
1017   case Bytecodes::_dup2:        inputs = 2;  break;
1018   case Bytecodes::_dup2_x1:     inputs = 3;  break;
1019   case Bytecodes::_dup2_x2:     inputs = 4;  break;
1020   case Bytecodes::_swap:        inputs = 2;  break;
1021   case Bytecodes::_arraylength: inputs = 1;  break;
1022 
1023   case Bytecodes::_getstatic:
1024   case Bytecodes::_putstatic:
1025   case Bytecodes::_getfield:
1026   case Bytecodes::_putfield:
1027     {
1028       bool ignored_will_link;
1029       ciField* field = method()->get_field_at_bci(bci(), ignored_will_link);
1030       int      size  = field->type()->size();
1031       bool is_get = (depth >= 0), is_static = (depth & 1);
1032       inputs = (is_static ? 0 : 1);
1033       if (is_get) {
1034         depth = size - inputs;
1035       } else {
1036         inputs += size;        // putxxx pops the value from the stack
1037         depth = - inputs;
1038       }
1039     }
1040     break;
1041 
1042   case Bytecodes::_invokevirtual:
1043   case Bytecodes::_invokespecial:
1044   case Bytecodes::_invokestatic:
1045   case Bytecodes::_invokedynamic:
1046   case Bytecodes::_invokeinterface:
1047     {
1048       bool ignored_will_link;
1049       ciSignature* declared_signature = NULL;
1050       ciMethod* ignored_callee = method()->get_method_at_bci(bci(), ignored_will_link, &declared_signature);
1051       assert(declared_signature != NULL, "cannot be null");
1052       inputs   = declared_signature->arg_size_for_bc(code);
1053       int size = declared_signature->return_type()->size();
1054       depth = size - inputs;
1055     }
1056     break;
1057 
1058   case Bytecodes::_multianewarray:
1059     {
1060       ciBytecodeStream iter(method());
1061       iter.reset_to_bci(bci());
1062       iter.next();
1063       inputs = iter.get_dimensions();
1064       assert(rsize == 1, "");
1065       depth = rsize - inputs;
1066     }
1067     break;
1068 
1069   case Bytecodes::_ireturn:
1070   case Bytecodes::_lreturn:
1071   case Bytecodes::_freturn:
1072   case Bytecodes::_dreturn:
1073   case Bytecodes::_areturn:
1074     assert(rsize = -depth, "");
1075     inputs = rsize;
1076     break;
1077 
1078   case Bytecodes::_jsr:
1079   case Bytecodes::_jsr_w:
1080     inputs = 0;
1081     depth  = 1;                  // S.B. depth=1, not zero
1082     break;
1083 
1084   default:
1085     // bytecode produces a typed result
1086     inputs = rsize - depth;
1087     assert(inputs >= 0, "");
1088     break;
1089   }
1090 
1091 #ifdef ASSERT
1092   // spot check
1093   int outputs = depth + inputs;
1094   assert(outputs >= 0, "sanity");
1095   switch (code) {
1096   case Bytecodes::_checkcast: assert(inputs == 1 && outputs == 1, ""); break;
1097   case Bytecodes::_athrow:    assert(inputs == 1 && outputs == 0, ""); break;
1098   case Bytecodes::_aload_0:   assert(inputs == 0 && outputs == 1, ""); break;
1099   case Bytecodes::_return:    assert(inputs == 0 && outputs == 0, ""); break;
1100   case Bytecodes::_drem:      assert(inputs == 4 && outputs == 2, ""); break;
1101   }
1102 #endif //ASSERT
1103 
1104   return true;
1105 }
1106 
1107 
1108 
1109 //------------------------------basic_plus_adr---------------------------------
1110 Node* GraphKit::basic_plus_adr(Node* base, Node* ptr, Node* offset) {
1111   // short-circuit a common case
1112   if (offset == intcon(0))  return ptr;
1113   return _gvn.transform( new (C) AddPNode(base, ptr, offset) );
1114 }
1115 
1116 Node* GraphKit::ConvI2L(Node* offset) {
1117   // short-circuit a common case
1118   jint offset_con = find_int_con(offset, Type::OffsetBot);
1119   if (offset_con != Type::OffsetBot) {
1120     return longcon((jlong) offset_con);
1121   }
1122   return _gvn.transform( new (C) ConvI2LNode(offset));
1123 }
1124 Node* GraphKit::ConvL2I(Node* offset) {
1125   // short-circuit a common case
1126   jlong offset_con = find_long_con(offset, (jlong)Type::OffsetBot);
1127   if (offset_con != (jlong)Type::OffsetBot) {
1128     return intcon((int) offset_con);
1129   }
1130   return _gvn.transform( new (C) ConvL2INode(offset));
1131 }
1132 
1133 //-------------------------load_object_klass-----------------------------------
1134 Node* GraphKit::load_object_klass(Node* obj) {
1135   // Special-case a fresh allocation to avoid building nodes:
1136   Node* akls = AllocateNode::Ideal_klass(obj, &_gvn);
1137   if (akls != NULL)  return akls;
1138   Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes());
1139   return _gvn.transform( LoadKlassNode::make(_gvn, immutable_memory(), k_adr, TypeInstPtr::KLASS) );
1140 }
1141 
1142 //-------------------------load_array_length-----------------------------------
1143 Node* GraphKit::load_array_length(Node* array) {
1144   // Special-case a fresh allocation to avoid building nodes:
1145   AllocateArrayNode* alloc = AllocateArrayNode::Ideal_array_allocation(array, &_gvn);
1146   Node *alen;
1147   if (alloc == NULL) {
1148     Node *r_adr = basic_plus_adr(array, arrayOopDesc::length_offset_in_bytes());
1149     alen = _gvn.transform( new (C) LoadRangeNode(0, immutable_memory(), r_adr, TypeInt::POS));
1150   } else {
1151     alen = alloc->Ideal_length();
1152     Node* ccast = alloc->make_ideal_length(_gvn.type(array)->is_oopptr(), &_gvn);
1153     if (ccast != alen) {
1154       alen = _gvn.transform(ccast);
1155     }
1156   }
1157   return alen;
1158 }
1159 
1160 //------------------------------do_null_check----------------------------------
1161 // Helper function to do a NULL pointer check.  Returned value is
1162 // the incoming address with NULL casted away.  You are allowed to use the
1163 // not-null value only if you are control dependent on the test.
1164 extern int explicit_null_checks_inserted,
1165            explicit_null_checks_elided;
1166 Node* GraphKit::null_check_common(Node* value, BasicType type,
1167                                   // optional arguments for variations:
1168                                   bool assert_null,
1169                                   Node* *null_control) {
1170   assert(!assert_null || null_control == NULL, "not both at once");
1171   if (stopped())  return top();
1172   if (!GenerateCompilerNullChecks && !assert_null && null_control == NULL) {
1173     // For some performance testing, we may wish to suppress null checking.
1174     value = cast_not_null(value);   // Make it appear to be non-null (4962416).
1175     return value;
1176   }
1177   explicit_null_checks_inserted++;
1178 
1179   // Construct NULL check
1180   Node *chk = NULL;
1181   switch(type) {
1182     case T_LONG   : chk = new (C) CmpLNode(value, _gvn.zerocon(T_LONG)); break;
1183     case T_INT    : chk = new (C) CmpINode(value, _gvn.intcon(0)); break;
1184     case T_ARRAY  : // fall through
1185       type = T_OBJECT;  // simplify further tests
1186     case T_OBJECT : {
1187       const Type *t = _gvn.type( value );
1188 
1189       const TypeOopPtr* tp = t->isa_oopptr();
1190       if (tp != NULL && tp->klass() != NULL && !tp->klass()->is_loaded()
1191           // Only for do_null_check, not any of its siblings:
1192           && !assert_null && null_control == NULL) {
1193         // Usually, any field access or invocation on an unloaded oop type
1194         // will simply fail to link, since the statically linked class is
1195         // likely also to be unloaded.  However, in -Xcomp mode, sometimes
1196         // the static class is loaded but the sharper oop type is not.
1197         // Rather than checking for this obscure case in lots of places,
1198         // we simply observe that a null check on an unloaded class
1199         // will always be followed by a nonsense operation, so we
1200         // can just issue the uncommon trap here.
1201         // Our access to the unloaded class will only be correct
1202         // after it has been loaded and initialized, which requires
1203         // a trip through the interpreter.
1204 #ifndef PRODUCT
1205         if (WizardMode) { tty->print("Null check of unloaded "); tp->klass()->print(); tty->cr(); }
1206 #endif
1207         uncommon_trap(Deoptimization::Reason_unloaded,
1208                       Deoptimization::Action_reinterpret,
1209                       tp->klass(), "!loaded");
1210         return top();
1211       }
1212 
1213       if (assert_null) {
1214         // See if the type is contained in NULL_PTR.
1215         // If so, then the value is already null.
1216         if (t->higher_equal(TypePtr::NULL_PTR)) {
1217           explicit_null_checks_elided++;
1218           return value;           // Elided null assert quickly!
1219         }
1220       } else {
1221         // See if mixing in the NULL pointer changes type.
1222         // If so, then the NULL pointer was not allowed in the original
1223         // type.  In other words, "value" was not-null.
1224         if (t->meet(TypePtr::NULL_PTR) != t) {
1225           // same as: if (!TypePtr::NULL_PTR->higher_equal(t)) ...
1226           explicit_null_checks_elided++;
1227           return value;           // Elided null check quickly!
1228         }
1229       }
1230       chk = new (C) CmpPNode( value, null() );
1231       break;
1232     }
1233 
1234     default:
1235       fatal(err_msg_res("unexpected type: %s", type2name(type)));
1236   }
1237   assert(chk != NULL, "sanity check");
1238   chk = _gvn.transform(chk);
1239 
1240   BoolTest::mask btest = assert_null ? BoolTest::eq : BoolTest::ne;
1241   BoolNode *btst = new (C) BoolNode( chk, btest);
1242   Node   *tst = _gvn.transform( btst );
1243 
1244   //-----------
1245   // if peephole optimizations occurred, a prior test existed.
1246   // If a prior test existed, maybe it dominates as we can avoid this test.
1247   if (tst != btst && type == T_OBJECT) {
1248     // At this point we want to scan up the CFG to see if we can
1249     // find an identical test (and so avoid this test altogether).
1250     Node *cfg = control();
1251     int depth = 0;
1252     while( depth < 16 ) {       // Limit search depth for speed
1253       if( cfg->Opcode() == Op_IfTrue &&
1254           cfg->in(0)->in(1) == tst ) {
1255         // Found prior test.  Use "cast_not_null" to construct an identical
1256         // CastPP (and hence hash to) as already exists for the prior test.
1257         // Return that casted value.
1258         if (assert_null) {
1259           replace_in_map(value, null());
1260           return null();  // do not issue the redundant test
1261         }
1262         Node *oldcontrol = control();
1263         set_control(cfg);
1264         Node *res = cast_not_null(value);
1265         set_control(oldcontrol);
1266         explicit_null_checks_elided++;
1267         return res;
1268       }
1269       cfg = IfNode::up_one_dom(cfg, /*linear_only=*/ true);
1270       if (cfg == NULL)  break;  // Quit at region nodes
1271       depth++;
1272     }
1273   }
1274 
1275   //-----------
1276   // Branch to failure if null
1277   float ok_prob = PROB_MAX;  // a priori estimate:  nulls never happen
1278   Deoptimization::DeoptReason reason;
1279   if (assert_null)
1280     reason = Deoptimization::Reason_null_assert;
1281   else if (type == T_OBJECT)
1282     reason = Deoptimization::Reason_null_check;
1283   else
1284     reason = Deoptimization::Reason_div0_check;
1285 
1286   // %%% Since Reason_unhandled is not recorded on a per-bytecode basis,
1287   // ciMethodData::has_trap_at will return a conservative -1 if any
1288   // must-be-null assertion has failed.  This could cause performance
1289   // problems for a method after its first do_null_assert failure.
1290   // Consider using 'Reason_class_check' instead?
1291 
1292   // To cause an implicit null check, we set the not-null probability
1293   // to the maximum (PROB_MAX).  For an explicit check the probability
1294   // is set to a smaller value.
1295   if (null_control != NULL || too_many_traps(reason)) {
1296     // probability is less likely
1297     ok_prob =  PROB_LIKELY_MAG(3);
1298   } else if (!assert_null &&
1299              (ImplicitNullCheckThreshold > 0) &&
1300              method() != NULL &&
1301              (method()->method_data()->trap_count(reason)
1302               >= (uint)ImplicitNullCheckThreshold)) {
1303     ok_prob =  PROB_LIKELY_MAG(3);
1304   }
1305 
1306   if (null_control != NULL) {
1307     IfNode* iff = create_and_map_if(control(), tst, ok_prob, COUNT_UNKNOWN);
1308     Node* null_true = _gvn.transform( new (C) IfFalseNode(iff));
1309     set_control(      _gvn.transform( new (C) IfTrueNode(iff)));
1310     if (null_true == top())
1311       explicit_null_checks_elided++;
1312     (*null_control) = null_true;
1313   } else {
1314     BuildCutout unless(this, tst, ok_prob);
1315     // Check for optimizer eliding test at parse time
1316     if (stopped()) {
1317       // Failure not possible; do not bother making uncommon trap.
1318       explicit_null_checks_elided++;
1319     } else if (assert_null) {
1320       uncommon_trap(reason,
1321                     Deoptimization::Action_make_not_entrant,
1322                     NULL, "assert_null");
1323     } else {
1324       replace_in_map(value, zerocon(type));
1325       builtin_throw(reason);
1326     }
1327   }
1328 
1329   // Must throw exception, fall-thru not possible?
1330   if (stopped()) {
1331     return top();               // No result
1332   }
1333 
1334   if (assert_null) {
1335     // Cast obj to null on this path.
1336     replace_in_map(value, zerocon(type));
1337     return zerocon(type);
1338   }
1339 
1340   // Cast obj to not-null on this path, if there is no null_control.
1341   // (If there is a null_control, a non-null value may come back to haunt us.)
1342   if (type == T_OBJECT) {
1343     Node* cast = cast_not_null(value, false);
1344     if (null_control == NULL || (*null_control) == top())
1345       replace_in_map(value, cast);
1346     value = cast;
1347   }
1348 
1349   return value;
1350 }
1351 
1352 
1353 //------------------------------cast_not_null----------------------------------
1354 // Cast obj to not-null on this path
1355 Node* GraphKit::cast_not_null(Node* obj, bool do_replace_in_map) {
1356   const Type *t = _gvn.type(obj);
1357   const Type *t_not_null = t->join(TypePtr::NOTNULL);
1358   // Object is already not-null?
1359   if( t == t_not_null ) return obj;
1360 
1361   Node *cast = new (C) CastPPNode(obj,t_not_null);
1362   cast->init_req(0, control());
1363   cast = _gvn.transform( cast );
1364 
1365   // Scan for instances of 'obj' in the current JVM mapping.
1366   // These instances are known to be not-null after the test.
1367   if (do_replace_in_map)
1368     replace_in_map(obj, cast);
1369 
1370   return cast;                  // Return casted value
1371 }
1372 
1373 
1374 //--------------------------replace_in_map-------------------------------------
1375 void GraphKit::replace_in_map(Node* old, Node* neww) {
1376   this->map()->replace_edge(old, neww);
1377 
1378   // Note: This operation potentially replaces any edge
1379   // on the map.  This includes locals, stack, and monitors
1380   // of the current (innermost) JVM state.
1381 
1382   // We can consider replacing in caller maps.
1383   // The idea would be that an inlined function's null checks
1384   // can be shared with the entire inlining tree.
1385   // The expense of doing this is that the PreserveJVMState class
1386   // would have to preserve caller states too, with a deep copy.
1387 }
1388 
1389 
1390 //=============================================================================
1391 //--------------------------------memory---------------------------------------
1392 Node* GraphKit::memory(uint alias_idx) {
1393   MergeMemNode* mem = merged_memory();
1394   Node* p = mem->memory_at(alias_idx);
1395   _gvn.set_type(p, Type::MEMORY);  // must be mapped
1396   return p;
1397 }
1398 
1399 //-----------------------------reset_memory------------------------------------
1400 Node* GraphKit::reset_memory() {
1401   Node* mem = map()->memory();
1402   // do not use this node for any more parsing!
1403   debug_only( map()->set_memory((Node*)NULL) );
1404   return _gvn.transform( mem );
1405 }
1406 
1407 //------------------------------set_all_memory---------------------------------
1408 void GraphKit::set_all_memory(Node* newmem) {
1409   Node* mergemem = MergeMemNode::make(C, newmem);
1410   gvn().set_type_bottom(mergemem);
1411   map()->set_memory(mergemem);
1412 }
1413 
1414 //------------------------------set_all_memory_call----------------------------
1415 void GraphKit::set_all_memory_call(Node* call, bool separate_io_proj) {
1416   Node* newmem = _gvn.transform( new (C) ProjNode(call, TypeFunc::Memory, separate_io_proj) );
1417   set_all_memory(newmem);
1418 }
1419 
1420 //=============================================================================
1421 //
1422 // parser factory methods for MemNodes
1423 //
1424 // These are layered on top of the factory methods in LoadNode and StoreNode,
1425 // and integrate with the parser's memory state and _gvn engine.
1426 //
1427 
1428 // factory methods in "int adr_idx"
1429 Node* GraphKit::make_load(Node* ctl, Node* adr, const Type* t, BasicType bt,
1430                           int adr_idx,
1431                           bool require_atomic_access) {
1432   assert(adr_idx != Compile::AliasIdxTop, "use other make_load factory" );
1433   const TypePtr* adr_type = NULL; // debug-mode-only argument
1434   debug_only(adr_type = C->get_adr_type(adr_idx));
1435   Node* mem = memory(adr_idx);
1436   Node* ld;
1437   if (require_atomic_access && bt == T_LONG) {
1438     ld = LoadLNode::make_atomic(C, ctl, mem, adr, adr_type, t);
1439   } else {
1440     ld = LoadNode::make(_gvn, ctl, mem, adr, adr_type, t, bt);
1441   }
1442   ld = _gvn.transform(ld);
1443   if ((bt == T_OBJECT) && C->do_escape_analysis() || C->eliminate_boxing()) {
1444     // Improve graph before escape analysis and boxing elimination.
1445     record_for_igvn(ld);
1446   }
1447   return ld;
1448 }
1449 
1450 Node* GraphKit::store_to_memory(Node* ctl, Node* adr, Node *val, BasicType bt,
1451                                 int adr_idx,
1452                                 bool require_atomic_access) {
1453   assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
1454   const TypePtr* adr_type = NULL;
1455   debug_only(adr_type = C->get_adr_type(adr_idx));
1456   Node *mem = memory(adr_idx);
1457   Node* st;
1458   if (require_atomic_access && bt == T_LONG) {
1459     st = StoreLNode::make_atomic(C, ctl, mem, adr, adr_type, val);
1460   } else {
1461     st = StoreNode::make(_gvn, ctl, mem, adr, adr_type, val, bt);
1462   }
1463   st = _gvn.transform(st);
1464   set_memory(st, adr_idx);
1465   // Back-to-back stores can only remove intermediate store with DU info
1466   // so push on worklist for optimizer.
1467   if (mem->req() > MemNode::Address && adr == mem->in(MemNode::Address))
1468     record_for_igvn(st);
1469 
1470   return st;
1471 }
1472 
1473 
1474 void GraphKit::pre_barrier(bool do_load,
1475                            Node* ctl,
1476                            Node* obj,
1477                            Node* adr,
1478                            uint  adr_idx,
1479                            Node* val,
1480                            const TypeOopPtr* val_type,
1481                            Node* pre_val,
1482                            BasicType bt) {
1483 
1484   BarrierSet* bs = Universe::heap()->barrier_set();
1485   set_control(ctl);
1486   switch (bs->kind()) {
1487     case BarrierSet::G1SATBCT:
1488     case BarrierSet::G1SATBCTLogging:
1489       g1_write_barrier_pre(do_load, obj, adr, adr_idx, val, val_type, pre_val, bt);
1490       break;
1491 
1492     case BarrierSet::CardTableModRef:
1493     case BarrierSet::CardTableExtension:
1494     case BarrierSet::ModRef:
1495       break;
1496 
1497     case BarrierSet::Other:
1498     default      :
1499       ShouldNotReachHere();
1500 
1501   }
1502 }
1503 
1504 bool GraphKit::can_move_pre_barrier() const {
1505   BarrierSet* bs = Universe::heap()->barrier_set();
1506   switch (bs->kind()) {
1507     case BarrierSet::G1SATBCT:
1508     case BarrierSet::G1SATBCTLogging:
1509       return true; // Can move it if no safepoint
1510 
1511     case BarrierSet::CardTableModRef:
1512     case BarrierSet::CardTableExtension:
1513     case BarrierSet::ModRef:
1514       return true; // There is no pre-barrier
1515 
1516     case BarrierSet::Other:
1517     default      :
1518       ShouldNotReachHere();
1519   }
1520   return false;
1521 }
1522 
1523 void GraphKit::post_barrier(Node* ctl,
1524                             Node* store,
1525                             Node* obj,
1526                             Node* adr,
1527                             uint  adr_idx,
1528                             Node* val,
1529                             BasicType bt,
1530                             bool use_precise) {
1531   BarrierSet* bs = Universe::heap()->barrier_set();
1532   set_control(ctl);
1533   switch (bs->kind()) {
1534     case BarrierSet::G1SATBCT:
1535     case BarrierSet::G1SATBCTLogging:
1536       g1_write_barrier_post(store, obj, adr, adr_idx, val, bt, use_precise);
1537       break;
1538 
1539     case BarrierSet::CardTableModRef:
1540     case BarrierSet::CardTableExtension:
1541       write_barrier_post(store, obj, adr, adr_idx, val, use_precise);
1542       break;
1543 
1544     case BarrierSet::ModRef:
1545       break;
1546 
1547     case BarrierSet::Other:
1548     default      :
1549       ShouldNotReachHere();
1550 
1551   }
1552 }
1553 
1554 Node* GraphKit::store_oop(Node* ctl,
1555                           Node* obj,
1556                           Node* adr,
1557                           const TypePtr* adr_type,
1558                           Node* val,
1559                           const TypeOopPtr* val_type,
1560                           BasicType bt,
1561                           bool use_precise) {
1562   // Transformation of a value which could be NULL pointer (CastPP #NULL)
1563   // could be delayed during Parse (for example, in adjust_map_after_if()).
1564   // Execute transformation here to avoid barrier generation in such case.
1565   if (_gvn.type(val) == TypePtr::NULL_PTR)
1566     val = _gvn.makecon(TypePtr::NULL_PTR);
1567 
1568   set_control(ctl);
1569   if (stopped()) return top(); // Dead path ?
1570 
1571   assert(bt == T_OBJECT, "sanity");
1572   assert(val != NULL, "not dead path");
1573   uint adr_idx = C->get_alias_index(adr_type);
1574   assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
1575 
1576   pre_barrier(true /* do_load */,
1577               control(), obj, adr, adr_idx, val, val_type,
1578               NULL /* pre_val */,
1579               bt);
1580 
1581   Node* store = store_to_memory(control(), adr, val, bt, adr_idx);
1582   post_barrier(control(), store, obj, adr, adr_idx, val, bt, use_precise);
1583   return store;
1584 }
1585 
1586 // Could be an array or object we don't know at compile time (unsafe ref.)
1587 Node* GraphKit::store_oop_to_unknown(Node* ctl,
1588                              Node* obj,   // containing obj
1589                              Node* adr,  // actual adress to store val at
1590                              const TypePtr* adr_type,
1591                              Node* val,
1592                              BasicType bt) {
1593   Compile::AliasType* at = C->alias_type(adr_type);
1594   const TypeOopPtr* val_type = NULL;
1595   if (adr_type->isa_instptr()) {
1596     if (at->field() != NULL) {
1597       // known field.  This code is a copy of the do_put_xxx logic.
1598       ciField* field = at->field();
1599       if (!field->type()->is_loaded()) {
1600         val_type = TypeInstPtr::BOTTOM;
1601       } else {
1602         val_type = TypeOopPtr::make_from_klass(field->type()->as_klass());
1603       }
1604     }
1605   } else if (adr_type->isa_aryptr()) {
1606     val_type = adr_type->is_aryptr()->elem()->make_oopptr();
1607   }
1608   if (val_type == NULL) {
1609     val_type = TypeInstPtr::BOTTOM;
1610   }
1611   return store_oop(ctl, obj, adr, adr_type, val, val_type, bt, true);
1612 }
1613 
1614 
1615 //-------------------------array_element_address-------------------------
1616 Node* GraphKit::array_element_address(Node* ary, Node* idx, BasicType elembt,
1617                                       const TypeInt* sizetype) {
1618   uint shift  = exact_log2(type2aelembytes(elembt));
1619   uint header = arrayOopDesc::base_offset_in_bytes(elembt);
1620 
1621   // short-circuit a common case (saves lots of confusing waste motion)
1622   jint idx_con = find_int_con(idx, -1);
1623   if (idx_con >= 0) {
1624     intptr_t offset = header + ((intptr_t)idx_con << shift);
1625     return basic_plus_adr(ary, offset);
1626   }
1627 
1628   // must be correct type for alignment purposes
1629   Node* base  = basic_plus_adr(ary, header);
1630 #ifdef _LP64
1631   // The scaled index operand to AddP must be a clean 64-bit value.
1632   // Java allows a 32-bit int to be incremented to a negative
1633   // value, which appears in a 64-bit register as a large
1634   // positive number.  Using that large positive number as an
1635   // operand in pointer arithmetic has bad consequences.
1636   // On the other hand, 32-bit overflow is rare, and the possibility
1637   // can often be excluded, if we annotate the ConvI2L node with
1638   // a type assertion that its value is known to be a small positive
1639   // number.  (The prior range check has ensured this.)
1640   // This assertion is used by ConvI2LNode::Ideal.
1641   int index_max = max_jint - 1;  // array size is max_jint, index is one less
1642   if (sizetype != NULL)  index_max = sizetype->_hi - 1;
1643   const TypeLong* lidxtype = TypeLong::make(CONST64(0), index_max, Type::WidenMax);
1644   idx = _gvn.transform( new (C) ConvI2LNode(idx, lidxtype) );
1645 #endif
1646   Node* scale = _gvn.transform( new (C) LShiftXNode(idx, intcon(shift)) );
1647   return basic_plus_adr(ary, base, scale);
1648 }
1649 
1650 //-------------------------load_array_element-------------------------
1651 Node* GraphKit::load_array_element(Node* ctl, Node* ary, Node* idx, const TypeAryPtr* arytype) {
1652   const Type* elemtype = arytype->elem();
1653   BasicType elembt = elemtype->array_element_basic_type();
1654   Node* adr = array_element_address(ary, idx, elembt, arytype->size());
1655   Node* ld = make_load(ctl, adr, elemtype, elembt, arytype);
1656   return ld;
1657 }
1658 
1659 //-------------------------set_arguments_for_java_call-------------------------
1660 // Arguments (pre-popped from the stack) are taken from the JVMS.
1661 void GraphKit::set_arguments_for_java_call(CallJavaNode* call) {
1662   // Add the call arguments:
1663   uint nargs = call->method()->arg_size();
1664   for (uint i = 0; i < nargs; i++) {
1665     Node* arg = argument(i);
1666     call->init_req(i + TypeFunc::Parms, arg);
1667   }
1668 }
1669 
1670 //---------------------------set_edges_for_java_call---------------------------
1671 // Connect a newly created call into the current JVMS.
1672 // A return value node (if any) is returned from set_edges_for_java_call.
1673 void GraphKit::set_edges_for_java_call(CallJavaNode* call, bool must_throw, bool separate_io_proj) {
1674 
1675   // Add the predefined inputs:
1676   call->init_req( TypeFunc::Control, control() );
1677   call->init_req( TypeFunc::I_O    , i_o() );
1678   call->init_req( TypeFunc::Memory , reset_memory() );
1679   call->init_req( TypeFunc::FramePtr, frameptr() );
1680   call->init_req( TypeFunc::ReturnAdr, top() );
1681 
1682   add_safepoint_edges(call, must_throw);
1683 
1684   Node* xcall = _gvn.transform(call);
1685 
1686   if (xcall == top()) {
1687     set_control(top());
1688     return;
1689   }
1690   assert(xcall == call, "call identity is stable");
1691 
1692   // Re-use the current map to produce the result.
1693 
1694   set_control(_gvn.transform(new (C) ProjNode(call, TypeFunc::Control)));
1695   set_i_o(    _gvn.transform(new (C) ProjNode(call, TypeFunc::I_O    , separate_io_proj)));
1696   set_all_memory_call(xcall, separate_io_proj);
1697 
1698   //return xcall;   // no need, caller already has it
1699 }
1700 
1701 Node* GraphKit::set_results_for_java_call(CallJavaNode* call, bool separate_io_proj) {
1702   if (stopped())  return top();  // maybe the call folded up?
1703 
1704   // Capture the return value, if any.
1705   Node* ret;
1706   if (call->method() == NULL ||
1707       call->method()->return_type()->basic_type() == T_VOID)
1708         ret = top();
1709   else  ret = _gvn.transform(new (C) ProjNode(call, TypeFunc::Parms));
1710 
1711   // Note:  Since any out-of-line call can produce an exception,
1712   // we always insert an I_O projection from the call into the result.
1713 
1714   make_slow_call_ex(call, env()->Throwable_klass(), separate_io_proj);
1715 
1716   if (separate_io_proj) {
1717     // The caller requested separate projections be used by the fall
1718     // through and exceptional paths, so replace the projections for
1719     // the fall through path.
1720     set_i_o(_gvn.transform( new (C) ProjNode(call, TypeFunc::I_O) ));
1721     set_all_memory(_gvn.transform( new (C) ProjNode(call, TypeFunc::Memory) ));
1722   }
1723   return ret;
1724 }
1725 
1726 //--------------------set_predefined_input_for_runtime_call--------------------
1727 // Reading and setting the memory state is way conservative here.
1728 // The real problem is that I am not doing real Type analysis on memory,
1729 // so I cannot distinguish card mark stores from other stores.  Across a GC
1730 // point the Store Barrier and the card mark memory has to agree.  I cannot
1731 // have a card mark store and its barrier split across the GC point from
1732 // either above or below.  Here I get that to happen by reading ALL of memory.
1733 // A better answer would be to separate out card marks from other memory.
1734 // For now, return the input memory state, so that it can be reused
1735 // after the call, if this call has restricted memory effects.
1736 Node* GraphKit::set_predefined_input_for_runtime_call(SafePointNode* call) {
1737   // Set fixed predefined input arguments
1738   Node* memory = reset_memory();
1739   call->init_req( TypeFunc::Control,   control()  );
1740   call->init_req( TypeFunc::I_O,       top()      ); // does no i/o
1741   call->init_req( TypeFunc::Memory,    memory     ); // may gc ptrs
1742   call->init_req( TypeFunc::FramePtr,  frameptr() );
1743   call->init_req( TypeFunc::ReturnAdr, top()      );
1744   return memory;
1745 }
1746 
1747 //-------------------set_predefined_output_for_runtime_call--------------------
1748 // Set control and memory (not i_o) from the call.
1749 // If keep_mem is not NULL, use it for the output state,
1750 // except for the RawPtr output of the call, if hook_mem is TypeRawPtr::BOTTOM.
1751 // If hook_mem is NULL, this call produces no memory effects at all.
1752 // If hook_mem is a Java-visible memory slice (such as arraycopy operands),
1753 // then only that memory slice is taken from the call.
1754 // In the last case, we must put an appropriate memory barrier before
1755 // the call, so as to create the correct anti-dependencies on loads
1756 // preceding the call.
1757 void GraphKit::set_predefined_output_for_runtime_call(Node* call,
1758                                                       Node* keep_mem,
1759                                                       const TypePtr* hook_mem) {
1760   // no i/o
1761   set_control(_gvn.transform( new (C) ProjNode(call,TypeFunc::Control) ));
1762   if (keep_mem) {
1763     // First clone the existing memory state
1764     set_all_memory(keep_mem);
1765     if (hook_mem != NULL) {
1766       // Make memory for the call
1767       Node* mem = _gvn.transform( new (C) ProjNode(call, TypeFunc::Memory) );
1768       // Set the RawPtr memory state only.  This covers all the heap top/GC stuff
1769       // We also use hook_mem to extract specific effects from arraycopy stubs.
1770       set_memory(mem, hook_mem);
1771     }
1772     // ...else the call has NO memory effects.
1773 
1774     // Make sure the call advertises its memory effects precisely.
1775     // This lets us build accurate anti-dependences in gcm.cpp.
1776     assert(C->alias_type(call->adr_type()) == C->alias_type(hook_mem),
1777            "call node must be constructed correctly");
1778   } else {
1779     assert(hook_mem == NULL, "");
1780     // This is not a "slow path" call; all memory comes from the call.
1781     set_all_memory_call(call);
1782   }
1783 }
1784 
1785 
1786 // Replace the call with the current state of the kit.
1787 void GraphKit::replace_call(CallNode* call, Node* result) {
1788   JVMState* ejvms = NULL;
1789   if (has_exceptions()) {
1790     ejvms = transfer_exceptions_into_jvms();
1791   }
1792 
1793   SafePointNode* final_state = stop();
1794 
1795   // Find all the needed outputs of this call
1796   CallProjections callprojs;
1797   call->extract_projections(&callprojs, true);
1798 
1799   Node* init_mem = call->in(TypeFunc::Memory);
1800   Node* final_mem = final_state->in(TypeFunc::Memory);
1801   Node* final_ctl = final_state->in(TypeFunc::Control);
1802   Node* final_io = final_state->in(TypeFunc::I_O);
1803 
1804   // Replace all the old call edges with the edges from the inlining result
1805   if (callprojs.fallthrough_catchproj != NULL) {
1806     C->gvn_replace_by(callprojs.fallthrough_catchproj, final_ctl);
1807   }
1808   if (callprojs.fallthrough_memproj != NULL) {
1809     C->gvn_replace_by(callprojs.fallthrough_memproj,   final_mem);
1810   }
1811   if (callprojs.fallthrough_ioproj != NULL) {
1812     C->gvn_replace_by(callprojs.fallthrough_ioproj,    final_io);
1813   }
1814 
1815   // Replace the result with the new result if it exists and is used
1816   if (callprojs.resproj != NULL && result != NULL) {
1817     C->gvn_replace_by(callprojs.resproj, result);
1818   }
1819 
1820   if (ejvms == NULL) {
1821     // No exception edges to simply kill off those paths
1822     if (callprojs.catchall_catchproj != NULL) {
1823       C->gvn_replace_by(callprojs.catchall_catchproj, C->top());
1824     }
1825     if (callprojs.catchall_memproj != NULL) {
1826       C->gvn_replace_by(callprojs.catchall_memproj,   C->top());
1827     }
1828     if (callprojs.catchall_ioproj != NULL) {
1829       C->gvn_replace_by(callprojs.catchall_ioproj,    C->top());
1830     }
1831     // Replace the old exception object with top
1832     if (callprojs.exobj != NULL) {
1833       C->gvn_replace_by(callprojs.exobj, C->top());
1834     }
1835   } else {
1836     GraphKit ekit(ejvms);
1837 
1838     // Load my combined exception state into the kit, with all phis transformed:
1839     SafePointNode* ex_map = ekit.combine_and_pop_all_exception_states();
1840 
1841     Node* ex_oop = ekit.use_exception_state(ex_map);
1842     if (callprojs.catchall_catchproj != NULL) {
1843       C->gvn_replace_by(callprojs.catchall_catchproj, ekit.control());
1844     }
1845     if (callprojs.catchall_memproj != NULL) {
1846       C->gvn_replace_by(callprojs.catchall_memproj,   ekit.reset_memory());
1847     }
1848     if (callprojs.catchall_ioproj != NULL) {
1849       C->gvn_replace_by(callprojs.catchall_ioproj,    ekit.i_o());
1850     }
1851 
1852     // Replace the old exception object with the newly created one
1853     if (callprojs.exobj != NULL) {
1854       C->gvn_replace_by(callprojs.exobj, ex_oop);
1855     }
1856   }
1857 
1858   // Disconnect the call from the graph
1859   call->disconnect_inputs(NULL, C);
1860   C->gvn_replace_by(call, C->top());
1861 
1862   // Clean up any MergeMems that feed other MergeMems since the
1863   // optimizer doesn't like that.
1864   if (final_mem->is_MergeMem()) {
1865     Node_List wl;
1866     for (SimpleDUIterator i(final_mem); i.has_next(); i.next()) {
1867       Node* m = i.get();
1868       if (m->is_MergeMem() && !wl.contains(m)) {
1869         wl.push(m);
1870       }
1871     }
1872     while (wl.size()  > 0) {
1873       _gvn.transform(wl.pop());
1874     }
1875   }
1876 }
1877 
1878 
1879 //------------------------------increment_counter------------------------------
1880 // for statistics: increment a VM counter by 1
1881 
1882 void GraphKit::increment_counter(address counter_addr) {
1883   Node* adr1 = makecon(TypeRawPtr::make(counter_addr));
1884   increment_counter(adr1);
1885 }
1886 
1887 void GraphKit::increment_counter(Node* counter_addr) {
1888   int adr_type = Compile::AliasIdxRaw;
1889   Node* ctrl = control();
1890   Node* cnt  = make_load(ctrl, counter_addr, TypeInt::INT, T_INT, adr_type);
1891   Node* incr = _gvn.transform(new (C) AddINode(cnt, _gvn.intcon(1)));
1892   store_to_memory( ctrl, counter_addr, incr, T_INT, adr_type );
1893 }
1894 
1895 
1896 //------------------------------uncommon_trap----------------------------------
1897 // Bail out to the interpreter in mid-method.  Implemented by calling the
1898 // uncommon_trap blob.  This helper function inserts a runtime call with the
1899 // right debug info.
1900 void GraphKit::uncommon_trap(int trap_request,
1901                              ciKlass* klass, const char* comment,
1902                              bool must_throw,
1903                              bool keep_exact_action) {
1904   if (failing())  stop();
1905   if (stopped())  return; // trap reachable?
1906 
1907   // Note:  If ProfileTraps is true, and if a deopt. actually
1908   // occurs here, the runtime will make sure an MDO exists.  There is
1909   // no need to call method()->ensure_method_data() at this point.
1910 
1911   // Set the stack pointer to the right value for reexecution:
1912   set_sp(reexecute_sp());
1913 
1914 #ifdef ASSERT
1915   if (!must_throw) {
1916     // Make sure the stack has at least enough depth to execute
1917     // the current bytecode.
1918     int inputs, ignored_depth;
1919     if (compute_stack_effects(inputs, ignored_depth)) {
1920       assert(sp() >= inputs, err_msg_res("must have enough JVMS stack to execute %s: sp=%d, inputs=%d",
1921              Bytecodes::name(java_bc()), sp(), inputs));
1922     }
1923   }
1924 #endif
1925 
1926   Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(trap_request);
1927   Deoptimization::DeoptAction action = Deoptimization::trap_request_action(trap_request);
1928 
1929   switch (action) {
1930   case Deoptimization::Action_maybe_recompile:
1931   case Deoptimization::Action_reinterpret:
1932     // Temporary fix for 6529811 to allow virtual calls to be sure they
1933     // get the chance to go from mono->bi->mega
1934     if (!keep_exact_action &&
1935         Deoptimization::trap_request_index(trap_request) < 0 &&
1936         too_many_recompiles(reason)) {
1937       // This BCI is causing too many recompilations.
1938       action = Deoptimization::Action_none;
1939       trap_request = Deoptimization::make_trap_request(reason, action);
1940     } else {
1941       C->set_trap_can_recompile(true);
1942     }
1943     break;
1944   case Deoptimization::Action_make_not_entrant:
1945     C->set_trap_can_recompile(true);
1946     break;
1947 #ifdef ASSERT
1948   case Deoptimization::Action_none:
1949   case Deoptimization::Action_make_not_compilable:
1950     break;
1951   default:
1952     fatal(err_msg_res("unknown action %d: %s", action, Deoptimization::trap_action_name(action)));
1953     break;
1954 #endif
1955   }
1956 
1957   if (TraceOptoParse) {
1958     char buf[100];
1959     tty->print_cr("Uncommon trap %s at bci:%d",
1960                   Deoptimization::format_trap_request(buf, sizeof(buf),
1961                                                       trap_request), bci());
1962   }
1963 
1964   CompileLog* log = C->log();
1965   if (log != NULL) {
1966     int kid = (klass == NULL)? -1: log->identify(klass);
1967     log->begin_elem("uncommon_trap bci='%d'", bci());
1968     char buf[100];
1969     log->print(" %s", Deoptimization::format_trap_request(buf, sizeof(buf),
1970                                                           trap_request));
1971     if (kid >= 0)         log->print(" klass='%d'", kid);
1972     if (comment != NULL)  log->print(" comment='%s'", comment);
1973     log->end_elem();
1974   }
1975 
1976   // Make sure any guarding test views this path as very unlikely
1977   Node *i0 = control()->in(0);
1978   if (i0 != NULL && i0->is_If()) {        // Found a guarding if test?
1979     IfNode *iff = i0->as_If();
1980     float f = iff->_prob;   // Get prob
1981     if (control()->Opcode() == Op_IfTrue) {
1982       if (f > PROB_UNLIKELY_MAG(4))
1983         iff->_prob = PROB_MIN;
1984     } else {
1985       if (f < PROB_LIKELY_MAG(4))
1986         iff->_prob = PROB_MAX;
1987     }
1988   }
1989 
1990   // Clear out dead values from the debug info.
1991   kill_dead_locals();
1992 
1993   // Now insert the uncommon trap subroutine call
1994   address call_addr = SharedRuntime::uncommon_trap_blob()->entry_point();
1995   const TypePtr* no_memory_effects = NULL;
1996   // Pass the index of the class to be loaded
1997   Node* call = make_runtime_call(RC_NO_LEAF | RC_UNCOMMON |
1998                                  (must_throw ? RC_MUST_THROW : 0),
1999                                  OptoRuntime::uncommon_trap_Type(),
2000                                  call_addr, "uncommon_trap", no_memory_effects,
2001                                  intcon(trap_request));
2002   assert(call->as_CallStaticJava()->uncommon_trap_request() == trap_request,
2003          "must extract request correctly from the graph");
2004   assert(trap_request != 0, "zero value reserved by uncommon_trap_request");
2005 
2006   call->set_req(TypeFunc::ReturnAdr, returnadr());
2007   // The debug info is the only real input to this call.
2008 
2009   // Halt-and-catch fire here.  The above call should never return!
2010   HaltNode* halt = new(C) HaltNode(control(), frameptr());
2011   _gvn.set_type_bottom(halt);
2012   root()->add_req(halt);
2013 
2014   stop_and_kill_map();
2015 }
2016 
2017 
2018 //--------------------------just_allocated_object------------------------------
2019 // Report the object that was just allocated.
2020 // It must be the case that there are no intervening safepoints.
2021 // We use this to determine if an object is so "fresh" that
2022 // it does not require card marks.
2023 Node* GraphKit::just_allocated_object(Node* current_control) {
2024   if (C->recent_alloc_ctl() == current_control)
2025     return C->recent_alloc_obj();
2026   return NULL;
2027 }
2028 
2029 
2030 void GraphKit::round_double_arguments(ciMethod* dest_method) {
2031   // (Note:  TypeFunc::make has a cache that makes this fast.)
2032   const TypeFunc* tf    = TypeFunc::make(dest_method);
2033   int             nargs = tf->_domain->_cnt - TypeFunc::Parms;
2034   for (int j = 0; j < nargs; j++) {
2035     const Type *targ = tf->_domain->field_at(j + TypeFunc::Parms);
2036     if( targ->basic_type() == T_DOUBLE ) {
2037       // If any parameters are doubles, they must be rounded before
2038       // the call, dstore_rounding does gvn.transform
2039       Node *arg = argument(j);
2040       arg = dstore_rounding(arg);
2041       set_argument(j, arg);
2042     }
2043   }
2044 }
2045 
2046 void GraphKit::round_double_result(ciMethod* dest_method) {
2047   // A non-strict method may return a double value which has an extended
2048   // exponent, but this must not be visible in a caller which is 'strict'
2049   // If a strict caller invokes a non-strict callee, round a double result
2050 
2051   BasicType result_type = dest_method->return_type()->basic_type();
2052   assert( method() != NULL, "must have caller context");
2053   if( result_type == T_DOUBLE && method()->is_strict() && !dest_method->is_strict() ) {
2054     // Destination method's return value is on top of stack
2055     // dstore_rounding() does gvn.transform
2056     Node *result = pop_pair();
2057     result = dstore_rounding(result);
2058     push_pair(result);
2059   }
2060 }
2061 
2062 // rounding for strict float precision conformance
2063 Node* GraphKit::precision_rounding(Node* n) {
2064   return UseStrictFP && _method->flags().is_strict()
2065     && UseSSE == 0 && Matcher::strict_fp_requires_explicit_rounding
2066     ? _gvn.transform( new (C) RoundFloatNode(0, n) )
2067     : n;
2068 }
2069 
2070 // rounding for strict double precision conformance
2071 Node* GraphKit::dprecision_rounding(Node *n) {
2072   return UseStrictFP && _method->flags().is_strict()
2073     && UseSSE <= 1 && Matcher::strict_fp_requires_explicit_rounding
2074     ? _gvn.transform( new (C) RoundDoubleNode(0, n) )
2075     : n;
2076 }
2077 
2078 // rounding for non-strict double stores
2079 Node* GraphKit::dstore_rounding(Node* n) {
2080   return Matcher::strict_fp_requires_explicit_rounding
2081     && UseSSE <= 1
2082     ? _gvn.transform( new (C) RoundDoubleNode(0, n) )
2083     : n;
2084 }
2085 
2086 //=============================================================================
2087 // Generate a fast path/slow path idiom.  Graph looks like:
2088 // [foo] indicates that 'foo' is a parameter
2089 //
2090 //              [in]     NULL
2091 //                 \    /
2092 //                  CmpP
2093 //                  Bool ne
2094 //                   If
2095 //                  /  \
2096 //              True    False-<2>
2097 //              / |
2098 //             /  cast_not_null
2099 //           Load  |    |   ^
2100 //        [fast_test]   |   |
2101 // gvn to   opt_test    |   |
2102 //          /    \      |  <1>
2103 //      True     False  |
2104 //        |         \\  |
2105 //   [slow_call]     \[fast_result]
2106 //    Ctl   Val       \      \
2107 //     |               \      \
2108 //    Catch       <1>   \      \
2109 //   /    \        ^     \      \
2110 //  Ex    No_Ex    |      \      \
2111 //  |       \   \  |       \ <2>  \
2112 //  ...      \  [slow_res] |  |    \   [null_result]
2113 //            \         \--+--+---  |  |
2114 //             \           | /    \ | /
2115 //              --------Region     Phi
2116 //
2117 //=============================================================================
2118 // Code is structured as a series of driver functions all called 'do_XXX' that
2119 // call a set of helper functions.  Helper functions first, then drivers.
2120 
2121 //------------------------------null_check_oop---------------------------------
2122 // Null check oop.  Set null-path control into Region in slot 3.
2123 // Make a cast-not-nullness use the other not-null control.  Return cast.
2124 Node* GraphKit::null_check_oop(Node* value, Node* *null_control,
2125                                bool never_see_null) {
2126   // Initial NULL check taken path
2127   (*null_control) = top();
2128   Node* cast = null_check_common(value, T_OBJECT, false, null_control);
2129 
2130   // Generate uncommon_trap:
2131   if (never_see_null && (*null_control) != top()) {
2132     // If we see an unexpected null at a check-cast we record it and force a
2133     // recompile; the offending check-cast will be compiled to handle NULLs.
2134     // If we see more than one offending BCI, then all checkcasts in the
2135     // method will be compiled to handle NULLs.
2136     PreserveJVMState pjvms(this);
2137     set_control(*null_control);
2138     replace_in_map(value, null());
2139     uncommon_trap(Deoptimization::Reason_null_check,
2140                   Deoptimization::Action_make_not_entrant);
2141     (*null_control) = top();    // NULL path is dead
2142   }
2143 
2144   // Cast away null-ness on the result
2145   return cast;
2146 }
2147 
2148 //------------------------------opt_iff----------------------------------------
2149 // Optimize the fast-check IfNode.  Set the fast-path region slot 2.
2150 // Return slow-path control.
2151 Node* GraphKit::opt_iff(Node* region, Node* iff) {
2152   IfNode *opt_iff = _gvn.transform(iff)->as_If();
2153 
2154   // Fast path taken; set region slot 2
2155   Node *fast_taken = _gvn.transform( new (C) IfFalseNode(opt_iff) );
2156   region->init_req(2,fast_taken); // Capture fast-control
2157 
2158   // Fast path not-taken, i.e. slow path
2159   Node *slow_taken = _gvn.transform( new (C) IfTrueNode(opt_iff) );
2160   return slow_taken;
2161 }
2162 
2163 //-----------------------------make_runtime_call-------------------------------
2164 Node* GraphKit::make_runtime_call(int flags,
2165                                   const TypeFunc* call_type, address call_addr,
2166                                   const char* call_name,
2167                                   const TypePtr* adr_type,
2168                                   // The following parms are all optional.
2169                                   // The first NULL ends the list.
2170                                   Node* parm0, Node* parm1,
2171                                   Node* parm2, Node* parm3,
2172                                   Node* parm4, Node* parm5,
2173                                   Node* parm6, Node* parm7) {
2174   // Slow-path call
2175   bool is_leaf = !(flags & RC_NO_LEAF);
2176   bool has_io  = (!is_leaf && !(flags & RC_NO_IO));
2177   if (call_name == NULL) {
2178     assert(!is_leaf, "must supply name for leaf");
2179     call_name = OptoRuntime::stub_name(call_addr);
2180   }
2181   CallNode* call;
2182   if (!is_leaf) {
2183     call = new(C) CallStaticJavaNode(call_type, call_addr, call_name,
2184                                            bci(), adr_type);
2185   } else if (flags & RC_NO_FP) {
2186     call = new(C) CallLeafNoFPNode(call_type, call_addr, call_name, adr_type);
2187   } else {
2188     call = new(C) CallLeafNode(call_type, call_addr, call_name, adr_type);
2189   }
2190 
2191   // The following is similar to set_edges_for_java_call,
2192   // except that the memory effects of the call are restricted to AliasIdxRaw.
2193 
2194   // Slow path call has no side-effects, uses few values
2195   bool wide_in  = !(flags & RC_NARROW_MEM);
2196   bool wide_out = (C->get_alias_index(adr_type) == Compile::AliasIdxBot);
2197 
2198   Node* prev_mem = NULL;
2199   if (wide_in) {
2200     prev_mem = set_predefined_input_for_runtime_call(call);
2201   } else {
2202     assert(!wide_out, "narrow in => narrow out");
2203     Node* narrow_mem = memory(adr_type);
2204     prev_mem = reset_memory();
2205     map()->set_memory(narrow_mem);
2206     set_predefined_input_for_runtime_call(call);
2207   }
2208 
2209   // Hook each parm in order.  Stop looking at the first NULL.
2210   if (parm0 != NULL) { call->init_req(TypeFunc::Parms+0, parm0);
2211   if (parm1 != NULL) { call->init_req(TypeFunc::Parms+1, parm1);
2212   if (parm2 != NULL) { call->init_req(TypeFunc::Parms+2, parm2);
2213   if (parm3 != NULL) { call->init_req(TypeFunc::Parms+3, parm3);
2214   if (parm4 != NULL) { call->init_req(TypeFunc::Parms+4, parm4);
2215   if (parm5 != NULL) { call->init_req(TypeFunc::Parms+5, parm5);
2216   if (parm6 != NULL) { call->init_req(TypeFunc::Parms+6, parm6);
2217   if (parm7 != NULL) { call->init_req(TypeFunc::Parms+7, parm7);
2218     /* close each nested if ===> */  } } } } } } } }
2219   assert(call->in(call->req()-1) != NULL, "must initialize all parms");
2220 
2221   if (!is_leaf) {
2222     // Non-leaves can block and take safepoints:
2223     add_safepoint_edges(call, ((flags & RC_MUST_THROW) != 0));
2224   }
2225   // Non-leaves can throw exceptions:
2226   if (has_io) {
2227     call->set_req(TypeFunc::I_O, i_o());
2228   }
2229 
2230   if (flags & RC_UNCOMMON) {
2231     // Set the count to a tiny probability.  Cf. Estimate_Block_Frequency.
2232     // (An "if" probability corresponds roughly to an unconditional count.
2233     // Sort of.)
2234     call->set_cnt(PROB_UNLIKELY_MAG(4));
2235   }
2236 
2237   Node* c = _gvn.transform(call);
2238   assert(c == call, "cannot disappear");
2239 
2240   if (wide_out) {
2241     // Slow path call has full side-effects.
2242     set_predefined_output_for_runtime_call(call);
2243   } else {
2244     // Slow path call has few side-effects, and/or sets few values.
2245     set_predefined_output_for_runtime_call(call, prev_mem, adr_type);
2246   }
2247 
2248   if (has_io) {
2249     set_i_o(_gvn.transform(new (C) ProjNode(call, TypeFunc::I_O)));
2250   }
2251   return call;
2252 
2253 }
2254 
2255 //------------------------------merge_memory-----------------------------------
2256 // Merge memory from one path into the current memory state.
2257 void GraphKit::merge_memory(Node* new_mem, Node* region, int new_path) {
2258   for (MergeMemStream mms(merged_memory(), new_mem->as_MergeMem()); mms.next_non_empty2(); ) {
2259     Node* old_slice = mms.force_memory();
2260     Node* new_slice = mms.memory2();
2261     if (old_slice != new_slice) {
2262       PhiNode* phi;
2263       if (new_slice->is_Phi() && new_slice->as_Phi()->region() == region) {
2264         phi = new_slice->as_Phi();
2265         #ifdef ASSERT
2266         if (old_slice->is_Phi() && old_slice->as_Phi()->region() == region)
2267           old_slice = old_slice->in(new_path);
2268         // Caller is responsible for ensuring that any pre-existing
2269         // phis are already aware of old memory.
2270         int old_path = (new_path > 1) ? 1 : 2;  // choose old_path != new_path
2271         assert(phi->in(old_path) == old_slice, "pre-existing phis OK");
2272         #endif
2273         mms.set_memory(phi);
2274       } else {
2275         phi = PhiNode::make(region, old_slice, Type::MEMORY, mms.adr_type(C));
2276         _gvn.set_type(phi, Type::MEMORY);
2277         phi->set_req(new_path, new_slice);
2278         mms.set_memory(_gvn.transform(phi));  // assume it is complete
2279       }
2280     }
2281   }
2282 }
2283 
2284 //------------------------------make_slow_call_ex------------------------------
2285 // Make the exception handler hookups for the slow call
2286 void GraphKit::make_slow_call_ex(Node* call, ciInstanceKlass* ex_klass, bool separate_io_proj) {
2287   if (stopped())  return;
2288 
2289   // Make a catch node with just two handlers:  fall-through and catch-all
2290   Node* i_o  = _gvn.transform( new (C) ProjNode(call, TypeFunc::I_O, separate_io_proj) );
2291   Node* catc = _gvn.transform( new (C) CatchNode(control(), i_o, 2) );
2292   Node* norm = _gvn.transform( new (C) CatchProjNode(catc, CatchProjNode::fall_through_index, CatchProjNode::no_handler_bci) );
2293   Node* excp = _gvn.transform( new (C) CatchProjNode(catc, CatchProjNode::catch_all_index,    CatchProjNode::no_handler_bci) );
2294 
2295   { PreserveJVMState pjvms(this);
2296     set_control(excp);
2297     set_i_o(i_o);
2298 
2299     if (excp != top()) {
2300       // Create an exception state also.
2301       // Use an exact type if the caller has specified a specific exception.
2302       const Type* ex_type = TypeOopPtr::make_from_klass_unique(ex_klass)->cast_to_ptr_type(TypePtr::NotNull);
2303       Node*       ex_oop  = new (C) CreateExNode(ex_type, control(), i_o);
2304       add_exception_state(make_exception_state(_gvn.transform(ex_oop)));
2305     }
2306   }
2307 
2308   // Get the no-exception control from the CatchNode.
2309   set_control(norm);
2310 }
2311 
2312 
2313 //-------------------------------gen_subtype_check-----------------------------
2314 // Generate a subtyping check.  Takes as input the subtype and supertype.
2315 // Returns 2 values: sets the default control() to the true path and returns
2316 // the false path.  Only reads invariant memory; sets no (visible) memory.
2317 // The PartialSubtypeCheckNode sets the hidden 1-word cache in the encoding
2318 // but that's not exposed to the optimizer.  This call also doesn't take in an
2319 // Object; if you wish to check an Object you need to load the Object's class
2320 // prior to coming here.
2321 Node* GraphKit::gen_subtype_check(Node* subklass, Node* superklass) {
2322   // Fast check for identical types, perhaps identical constants.
2323   // The types can even be identical non-constants, in cases
2324   // involving Array.newInstance, Object.clone, etc.
2325   if (subklass == superklass)
2326     return top();             // false path is dead; no test needed.
2327 
2328   if (_gvn.type(superklass)->singleton()) {
2329     ciKlass* superk = _gvn.type(superklass)->is_klassptr()->klass();
2330     ciKlass* subk   = _gvn.type(subklass)->is_klassptr()->klass();
2331 
2332     // In the common case of an exact superklass, try to fold up the
2333     // test before generating code.  You may ask, why not just generate
2334     // the code and then let it fold up?  The answer is that the generated
2335     // code will necessarily include null checks, which do not always
2336     // completely fold away.  If they are also needless, then they turn
2337     // into a performance loss.  Example:
2338     //    Foo[] fa = blah(); Foo x = fa[0]; fa[1] = x;
2339     // Here, the type of 'fa' is often exact, so the store check
2340     // of fa[1]=x will fold up, without testing the nullness of x.
2341     switch (static_subtype_check(superk, subk)) {
2342     case SSC_always_false:
2343       {
2344         Node* always_fail = control();
2345         set_control(top());
2346         return always_fail;
2347       }
2348     case SSC_always_true:
2349       return top();
2350     case SSC_easy_test:
2351       {
2352         // Just do a direct pointer compare and be done.
2353         Node* cmp = _gvn.transform( new(C) CmpPNode(subklass, superklass) );
2354         Node* bol = _gvn.transform( new(C) BoolNode(cmp, BoolTest::eq) );
2355         IfNode* iff = create_and_xform_if(control(), bol, PROB_STATIC_FREQUENT, COUNT_UNKNOWN);
2356         set_control( _gvn.transform( new(C) IfTrueNode (iff) ) );
2357         return       _gvn.transform( new(C) IfFalseNode(iff) );
2358       }
2359     case SSC_full_test:
2360       break;
2361     default:
2362       ShouldNotReachHere();
2363     }
2364   }
2365 
2366   // %%% Possible further optimization:  Even if the superklass is not exact,
2367   // if the subklass is the unique subtype of the superklass, the check
2368   // will always succeed.  We could leave a dependency behind to ensure this.
2369 
2370   // First load the super-klass's check-offset
2371   Node *p1 = basic_plus_adr( superklass, superklass, in_bytes(Klass::super_check_offset_offset()) );
2372   Node *chk_off = _gvn.transform( new (C) LoadINode( NULL, memory(p1), p1, _gvn.type(p1)->is_ptr() ) );
2373   int cacheoff_con = in_bytes(Klass::secondary_super_cache_offset());
2374   bool might_be_cache = (find_int_con(chk_off, cacheoff_con) == cacheoff_con);
2375 
2376   // Load from the sub-klass's super-class display list, or a 1-word cache of
2377   // the secondary superclass list, or a failing value with a sentinel offset
2378   // if the super-klass is an interface or exceptionally deep in the Java
2379   // hierarchy and we have to scan the secondary superclass list the hard way.
2380   // Worst-case type is a little odd: NULL is allowed as a result (usually
2381   // klass loads can never produce a NULL).
2382   Node *chk_off_X = ConvI2X(chk_off);
2383   Node *p2 = _gvn.transform( new (C) AddPNode(subklass,subklass,chk_off_X) );
2384   // For some types like interfaces the following loadKlass is from a 1-word
2385   // cache which is mutable so can't use immutable memory.  Other
2386   // types load from the super-class display table which is immutable.
2387   Node *kmem = might_be_cache ? memory(p2) : immutable_memory();
2388   Node *nkls = _gvn.transform( LoadKlassNode::make( _gvn, kmem, p2, _gvn.type(p2)->is_ptr(), TypeKlassPtr::OBJECT_OR_NULL ) );
2389 
2390   // Compile speed common case: ARE a subtype and we canNOT fail
2391   if( superklass == nkls )
2392     return top();             // false path is dead; no test needed.
2393 
2394   // See if we get an immediate positive hit.  Happens roughly 83% of the
2395   // time.  Test to see if the value loaded just previously from the subklass
2396   // is exactly the superklass.
2397   Node *cmp1 = _gvn.transform( new (C) CmpPNode( superklass, nkls ) );
2398   Node *bol1 = _gvn.transform( new (C) BoolNode( cmp1, BoolTest::eq ) );
2399   IfNode *iff1 = create_and_xform_if( control(), bol1, PROB_LIKELY(0.83f), COUNT_UNKNOWN );
2400   Node *iftrue1 = _gvn.transform( new (C) IfTrueNode ( iff1 ) );
2401   set_control(    _gvn.transform( new (C) IfFalseNode( iff1 ) ) );
2402 
2403   // Compile speed common case: Check for being deterministic right now.  If
2404   // chk_off is a constant and not equal to cacheoff then we are NOT a
2405   // subklass.  In this case we need exactly the 1 test above and we can
2406   // return those results immediately.
2407   if (!might_be_cache) {
2408     Node* not_subtype_ctrl = control();
2409     set_control(iftrue1); // We need exactly the 1 test above
2410     return not_subtype_ctrl;
2411   }
2412 
2413   // Gather the various success & failures here
2414   RegionNode *r_ok_subtype = new (C) RegionNode(4);
2415   record_for_igvn(r_ok_subtype);
2416   RegionNode *r_not_subtype = new (C) RegionNode(3);
2417   record_for_igvn(r_not_subtype);
2418 
2419   r_ok_subtype->init_req(1, iftrue1);
2420 
2421   // Check for immediate negative hit.  Happens roughly 11% of the time (which
2422   // is roughly 63% of the remaining cases).  Test to see if the loaded
2423   // check-offset points into the subklass display list or the 1-element
2424   // cache.  If it points to the display (and NOT the cache) and the display
2425   // missed then it's not a subtype.
2426   Node *cacheoff = _gvn.intcon(cacheoff_con);
2427   Node *cmp2 = _gvn.transform( new (C) CmpINode( chk_off, cacheoff ) );
2428   Node *bol2 = _gvn.transform( new (C) BoolNode( cmp2, BoolTest::ne ) );
2429   IfNode *iff2 = create_and_xform_if( control(), bol2, PROB_LIKELY(0.63f), COUNT_UNKNOWN );
2430   r_not_subtype->init_req(1, _gvn.transform( new (C) IfTrueNode (iff2) ) );
2431   set_control(                _gvn.transform( new (C) IfFalseNode(iff2) ) );
2432 
2433   // Check for self.  Very rare to get here, but it is taken 1/3 the time.
2434   // No performance impact (too rare) but allows sharing of secondary arrays
2435   // which has some footprint reduction.
2436   Node *cmp3 = _gvn.transform( new (C) CmpPNode( subklass, superklass ) );
2437   Node *bol3 = _gvn.transform( new (C) BoolNode( cmp3, BoolTest::eq ) );
2438   IfNode *iff3 = create_and_xform_if( control(), bol3, PROB_LIKELY(0.36f), COUNT_UNKNOWN );
2439   r_ok_subtype->init_req(2, _gvn.transform( new (C) IfTrueNode ( iff3 ) ) );
2440   set_control(               _gvn.transform( new (C) IfFalseNode( iff3 ) ) );
2441 
2442   // -- Roads not taken here: --
2443   // We could also have chosen to perform the self-check at the beginning
2444   // of this code sequence, as the assembler does.  This would not pay off
2445   // the same way, since the optimizer, unlike the assembler, can perform
2446   // static type analysis to fold away many successful self-checks.
2447   // Non-foldable self checks work better here in second position, because
2448   // the initial primary superclass check subsumes a self-check for most
2449   // types.  An exception would be a secondary type like array-of-interface,
2450   // which does not appear in its own primary supertype display.
2451   // Finally, we could have chosen to move the self-check into the
2452   // PartialSubtypeCheckNode, and from there out-of-line in a platform
2453   // dependent manner.  But it is worthwhile to have the check here,
2454   // where it can be perhaps be optimized.  The cost in code space is
2455   // small (register compare, branch).
2456 
2457   // Now do a linear scan of the secondary super-klass array.  Again, no real
2458   // performance impact (too rare) but it's gotta be done.
2459   // Since the code is rarely used, there is no penalty for moving it
2460   // out of line, and it can only improve I-cache density.
2461   // The decision to inline or out-of-line this final check is platform
2462   // dependent, and is found in the AD file definition of PartialSubtypeCheck.
2463   Node* psc = _gvn.transform(
2464     new (C) PartialSubtypeCheckNode(control(), subklass, superklass) );
2465 
2466   Node *cmp4 = _gvn.transform( new (C) CmpPNode( psc, null() ) );
2467   Node *bol4 = _gvn.transform( new (C) BoolNode( cmp4, BoolTest::ne ) );
2468   IfNode *iff4 = create_and_xform_if( control(), bol4, PROB_FAIR, COUNT_UNKNOWN );
2469   r_not_subtype->init_req(2, _gvn.transform( new (C) IfTrueNode (iff4) ) );
2470   r_ok_subtype ->init_req(3, _gvn.transform( new (C) IfFalseNode(iff4) ) );
2471 
2472   // Return false path; set default control to true path.
2473   set_control( _gvn.transform(r_ok_subtype) );
2474   return _gvn.transform(r_not_subtype);
2475 }
2476 
2477 //----------------------------static_subtype_check-----------------------------
2478 // Shortcut important common cases when superklass is exact:
2479 // (0) superklass is java.lang.Object (can occur in reflective code)
2480 // (1) subklass is already limited to a subtype of superklass => always ok
2481 // (2) subklass does not overlap with superklass => always fail
2482 // (3) superklass has NO subtypes and we can check with a simple compare.
2483 int GraphKit::static_subtype_check(ciKlass* superk, ciKlass* subk) {
2484   if (StressReflectiveCode) {
2485     return SSC_full_test;       // Let caller generate the general case.
2486   }
2487 
2488   if (superk == env()->Object_klass()) {
2489     return SSC_always_true;     // (0) this test cannot fail
2490   }
2491 
2492   ciType* superelem = superk;
2493   if (superelem->is_array_klass())
2494     superelem = superelem->as_array_klass()->base_element_type();
2495 
2496   if (!subk->is_interface()) {  // cannot trust static interface types yet
2497     if (subk->is_subtype_of(superk)) {
2498       return SSC_always_true;   // (1) false path dead; no dynamic test needed
2499     }
2500     if (!(superelem->is_klass() && superelem->as_klass()->is_interface()) &&
2501         !superk->is_subtype_of(subk)) {
2502       return SSC_always_false;
2503     }
2504   }
2505 
2506   // If casting to an instance klass, it must have no subtypes
2507   if (superk->is_interface()) {
2508     // Cannot trust interfaces yet.
2509     // %%% S.B. superk->nof_implementors() == 1
2510   } else if (superelem->is_instance_klass()) {
2511     ciInstanceKlass* ik = superelem->as_instance_klass();
2512     if (!ik->has_subklass() && !ik->is_interface()) {
2513       if (!ik->is_final()) {
2514         // Add a dependency if there is a chance of a later subclass.
2515         C->dependencies()->assert_leaf_type(ik);
2516       }
2517       return SSC_easy_test;     // (3) caller can do a simple ptr comparison
2518     }
2519   } else {
2520     // A primitive array type has no subtypes.
2521     return SSC_easy_test;       // (3) caller can do a simple ptr comparison
2522   }
2523 
2524   return SSC_full_test;
2525 }
2526 
2527 // Profile-driven exact type check:
2528 Node* GraphKit::type_check_receiver(Node* receiver, ciKlass* klass,
2529                                     float prob,
2530                                     Node* *casted_receiver) {
2531   const TypeKlassPtr* tklass = TypeKlassPtr::make(klass);
2532   Node* recv_klass = load_object_klass(receiver);
2533   Node* want_klass = makecon(tklass);
2534   Node* cmp = _gvn.transform( new(C) CmpPNode(recv_klass, want_klass) );
2535   Node* bol = _gvn.transform( new(C) BoolNode(cmp, BoolTest::eq) );
2536   IfNode* iff = create_and_xform_if(control(), bol, prob, COUNT_UNKNOWN);
2537   set_control( _gvn.transform( new(C) IfTrueNode (iff) ));
2538   Node* fail = _gvn.transform( new(C) IfFalseNode(iff) );
2539 
2540   const TypeOopPtr* recv_xtype = tklass->as_instance_type();
2541   assert(recv_xtype->klass_is_exact(), "");
2542 
2543   // Subsume downstream occurrences of receiver with a cast to
2544   // recv_xtype, since now we know what the type will be.
2545   Node* cast = new(C) CheckCastPPNode(control(), receiver, recv_xtype);
2546   (*casted_receiver) = _gvn.transform(cast);
2547   // (User must make the replace_in_map call.)
2548 
2549   return fail;
2550 }
2551 
2552 
2553 //------------------------------seems_never_null-------------------------------
2554 // Use null_seen information if it is available from the profile.
2555 // If we see an unexpected null at a type check we record it and force a
2556 // recompile; the offending check will be recompiled to handle NULLs.
2557 // If we see several offending BCIs, then all checks in the
2558 // method will be recompiled.
2559 bool GraphKit::seems_never_null(Node* obj, ciProfileData* data) {
2560   if (UncommonNullCast               // Cutout for this technique
2561       && obj != null()               // And not the -Xcomp stupid case?
2562       && !too_many_traps(Deoptimization::Reason_null_check)
2563       ) {
2564     if (data == NULL)
2565       // Edge case:  no mature data.  Be optimistic here.
2566       return true;
2567     // If the profile has not seen a null, assume it won't happen.
2568     assert(java_bc() == Bytecodes::_checkcast ||
2569            java_bc() == Bytecodes::_instanceof ||
2570            java_bc() == Bytecodes::_aastore, "MDO must collect null_seen bit here");
2571     return !data->as_BitData()->null_seen();
2572   }
2573   return false;
2574 }
2575 
2576 //------------------------maybe_cast_profiled_receiver-------------------------
2577 // If the profile has seen exactly one type, narrow to exactly that type.
2578 // Subsequent type checks will always fold up.
2579 Node* GraphKit::maybe_cast_profiled_receiver(Node* not_null_obj,
2580                                              ciProfileData* data,
2581                                              ciKlass* require_klass) {
2582   if (!UseTypeProfile || !TypeProfileCasts) return NULL;
2583   if (data == NULL)  return NULL;
2584 
2585   // Make sure we haven't already deoptimized from this tactic.
2586   if (too_many_traps(Deoptimization::Reason_class_check))
2587     return NULL;
2588 
2589   // (No, this isn't a call, but it's enough like a virtual call
2590   // to use the same ciMethod accessor to get the profile info...)
2591   ciCallProfile profile = method()->call_profile_at_bci(bci());
2592   if (profile.count() >= 0 &&         // no cast failures here
2593       profile.has_receiver(0) &&
2594       profile.morphism() == 1) {
2595     ciKlass* exact_kls = profile.receiver(0);
2596     if (require_klass == NULL ||
2597         static_subtype_check(require_klass, exact_kls) == SSC_always_true) {
2598       // If we narrow the type to match what the type profile sees,
2599       // we can then remove the rest of the cast.
2600       // This is a win, even if the exact_kls is very specific,
2601       // because downstream operations, such as method calls,
2602       // will often benefit from the sharper type.
2603       Node* exact_obj = not_null_obj; // will get updated in place...
2604       Node* slow_ctl  = type_check_receiver(exact_obj, exact_kls, 1.0,
2605                                             &exact_obj);
2606       { PreserveJVMState pjvms(this);
2607         set_control(slow_ctl);
2608         uncommon_trap(Deoptimization::Reason_class_check,
2609                       Deoptimization::Action_maybe_recompile);
2610       }
2611       replace_in_map(not_null_obj, exact_obj);
2612       return exact_obj;
2613     }
2614     // assert(ssc == SSC_always_true)... except maybe the profile lied to us.
2615   }
2616 
2617   return NULL;
2618 }
2619 
2620 
2621 //-------------------------------gen_instanceof--------------------------------
2622 // Generate an instance-of idiom.  Used by both the instance-of bytecode
2623 // and the reflective instance-of call.
2624 Node* GraphKit::gen_instanceof(Node* obj, Node* superklass) {
2625   kill_dead_locals();           // Benefit all the uncommon traps
2626   assert( !stopped(), "dead parse path should be checked in callers" );
2627   assert(!TypePtr::NULL_PTR->higher_equal(_gvn.type(superklass)->is_klassptr()),
2628          "must check for not-null not-dead klass in callers");
2629 
2630   // Make the merge point
2631   enum { _obj_path = 1, _fail_path, _null_path, PATH_LIMIT };
2632   RegionNode* region = new(C) RegionNode(PATH_LIMIT);
2633   Node*       phi    = new(C) PhiNode(region, TypeInt::BOOL);
2634   C->set_has_split_ifs(true); // Has chance for split-if optimization
2635 
2636   ciProfileData* data = NULL;
2637   if (java_bc() == Bytecodes::_instanceof) {  // Only for the bytecode
2638     data = method()->method_data()->bci_to_data(bci());
2639   }
2640   bool never_see_null = (ProfileDynamicTypes  // aggressive use of profile
2641                          && seems_never_null(obj, data));
2642 
2643   // Null check; get casted pointer; set region slot 3
2644   Node* null_ctl = top();
2645   Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null);
2646 
2647   // If not_null_obj is dead, only null-path is taken
2648   if (stopped()) {              // Doing instance-of on a NULL?
2649     set_control(null_ctl);
2650     return intcon(0);
2651   }
2652   region->init_req(_null_path, null_ctl);
2653   phi   ->init_req(_null_path, intcon(0)); // Set null path value
2654   if (null_ctl == top()) {
2655     // Do this eagerly, so that pattern matches like is_diamond_phi
2656     // will work even during parsing.
2657     assert(_null_path == PATH_LIMIT-1, "delete last");
2658     region->del_req(_null_path);
2659     phi   ->del_req(_null_path);
2660   }
2661 
2662   if (ProfileDynamicTypes && data != NULL) {
2663     Node* cast_obj = maybe_cast_profiled_receiver(not_null_obj, data, NULL);
2664     if (stopped()) {            // Profile disagrees with this path.
2665       set_control(null_ctl);    // Null is the only remaining possibility.
2666       return intcon(0);
2667     }
2668     if (cast_obj != NULL)
2669       not_null_obj = cast_obj;
2670   }
2671 
2672   // Load the object's klass
2673   Node* obj_klass = load_object_klass(not_null_obj);
2674 
2675   // Generate the subtype check
2676   Node* not_subtype_ctrl = gen_subtype_check(obj_klass, superklass);
2677 
2678   // Plug in the success path to the general merge in slot 1.
2679   region->init_req(_obj_path, control());
2680   phi   ->init_req(_obj_path, intcon(1));
2681 
2682   // Plug in the failing path to the general merge in slot 2.
2683   region->init_req(_fail_path, not_subtype_ctrl);
2684   phi   ->init_req(_fail_path, intcon(0));
2685 
2686   // Return final merged results
2687   set_control( _gvn.transform(region) );
2688   record_for_igvn(region);
2689   return _gvn.transform(phi);
2690 }
2691 
2692 //-------------------------------gen_checkcast---------------------------------
2693 // Generate a checkcast idiom.  Used by both the checkcast bytecode and the
2694 // array store bytecode.  Stack must be as-if BEFORE doing the bytecode so the
2695 // uncommon-trap paths work.  Adjust stack after this call.
2696 // If failure_control is supplied and not null, it is filled in with
2697 // the control edge for the cast failure.  Otherwise, an appropriate
2698 // uncommon trap or exception is thrown.
2699 Node* GraphKit::gen_checkcast(Node *obj, Node* superklass,
2700                               Node* *failure_control) {
2701   kill_dead_locals();           // Benefit all the uncommon traps
2702   const TypeKlassPtr *tk = _gvn.type(superklass)->is_klassptr();
2703   const Type *toop = TypeOopPtr::make_from_klass(tk->klass());
2704 
2705   // Fast cutout:  Check the case that the cast is vacuously true.
2706   // This detects the common cases where the test will short-circuit
2707   // away completely.  We do this before we perform the null check,
2708   // because if the test is going to turn into zero code, we don't
2709   // want a residual null check left around.  (Causes a slowdown,
2710   // for example, in some objArray manipulations, such as a[i]=a[j].)
2711   if (tk->singleton()) {
2712     const TypeOopPtr* objtp = _gvn.type(obj)->isa_oopptr();
2713     if (objtp != NULL && objtp->klass() != NULL) {
2714       switch (static_subtype_check(tk->klass(), objtp->klass())) {
2715       case SSC_always_true:
2716         return obj;
2717       case SSC_always_false:
2718         // It needs a null check because a null will *pass* the cast check.
2719         // A non-null value will always produce an exception.
2720         return null_assert(obj);
2721       }
2722     }
2723   }
2724 
2725   ciProfileData* data = NULL;
2726   if (failure_control == NULL) {        // use MDO in regular case only
2727     assert(java_bc() == Bytecodes::_aastore ||
2728            java_bc() == Bytecodes::_checkcast,
2729            "interpreter profiles type checks only for these BCs");
2730     data = method()->method_data()->bci_to_data(bci());
2731   }
2732 
2733   // Make the merge point
2734   enum { _obj_path = 1, _null_path, PATH_LIMIT };
2735   RegionNode* region = new (C) RegionNode(PATH_LIMIT);
2736   Node*       phi    = new (C) PhiNode(region, toop);
2737   C->set_has_split_ifs(true); // Has chance for split-if optimization
2738 
2739   // Use null-cast information if it is available
2740   bool never_see_null = ((failure_control == NULL)  // regular case only
2741                          && seems_never_null(obj, data));
2742 
2743   // Null check; get casted pointer; set region slot 3
2744   Node* null_ctl = top();
2745   Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null);
2746 
2747   // If not_null_obj is dead, only null-path is taken
2748   if (stopped()) {              // Doing instance-of on a NULL?
2749     set_control(null_ctl);
2750     return null();
2751   }
2752   region->init_req(_null_path, null_ctl);
2753   phi   ->init_req(_null_path, null());  // Set null path value
2754   if (null_ctl == top()) {
2755     // Do this eagerly, so that pattern matches like is_diamond_phi
2756     // will work even during parsing.
2757     assert(_null_path == PATH_LIMIT-1, "delete last");
2758     region->del_req(_null_path);
2759     phi   ->del_req(_null_path);
2760   }
2761 
2762   Node* cast_obj = NULL;
2763   if (data != NULL &&
2764       // Counter has never been decremented (due to cast failure).
2765       // ...This is a reasonable thing to expect.  It is true of
2766       // all casts inserted by javac to implement generic types.
2767       data->as_CounterData()->count() >= 0) {
2768     cast_obj = maybe_cast_profiled_receiver(not_null_obj, data, tk->klass());
2769     if (cast_obj != NULL) {
2770       if (failure_control != NULL) // failure is now impossible
2771         (*failure_control) = top();
2772       // adjust the type of the phi to the exact klass:
2773       phi->raise_bottom_type(_gvn.type(cast_obj)->meet(TypePtr::NULL_PTR));
2774     }
2775   }
2776 
2777   if (cast_obj == NULL) {
2778     // Load the object's klass
2779     Node* obj_klass = load_object_klass(not_null_obj);
2780 
2781     // Generate the subtype check
2782     Node* not_subtype_ctrl = gen_subtype_check( obj_klass, superklass );
2783 
2784     // Plug in success path into the merge
2785     cast_obj = _gvn.transform(new (C) CheckCastPPNode(control(),
2786                                                          not_null_obj, toop));
2787     // Failure path ends in uncommon trap (or may be dead - failure impossible)
2788     if (failure_control == NULL) {
2789       if (not_subtype_ctrl != top()) { // If failure is possible
2790         PreserveJVMState pjvms(this);
2791         set_control(not_subtype_ctrl);
2792         builtin_throw(Deoptimization::Reason_class_check, obj_klass);
2793       }
2794     } else {
2795       (*failure_control) = not_subtype_ctrl;
2796     }
2797   }
2798 
2799   region->init_req(_obj_path, control());
2800   phi   ->init_req(_obj_path, cast_obj);
2801 
2802   // A merge of NULL or Casted-NotNull obj
2803   Node* res = _gvn.transform(phi);
2804 
2805   // Note I do NOT always 'replace_in_map(obj,result)' here.
2806   //  if( tk->klass()->can_be_primary_super()  )
2807     // This means that if I successfully store an Object into an array-of-String
2808     // I 'forget' that the Object is really now known to be a String.  I have to
2809     // do this because we don't have true union types for interfaces - if I store
2810     // a Baz into an array-of-Interface and then tell the optimizer it's an
2811     // Interface, I forget that it's also a Baz and cannot do Baz-like field
2812     // references to it.  FIX THIS WHEN UNION TYPES APPEAR!
2813   //  replace_in_map( obj, res );
2814 
2815   // Return final merged results
2816   set_control( _gvn.transform(region) );
2817   record_for_igvn(region);
2818   return res;
2819 }
2820 
2821 //------------------------------next_monitor-----------------------------------
2822 // What number should be given to the next monitor?
2823 int GraphKit::next_monitor() {
2824   int current = jvms()->monitor_depth()* C->sync_stack_slots();
2825   int next = current + C->sync_stack_slots();
2826   // Keep the toplevel high water mark current:
2827   if (C->fixed_slots() < next)  C->set_fixed_slots(next);
2828   return current;
2829 }
2830 
2831 //------------------------------insert_mem_bar---------------------------------
2832 // Memory barrier to avoid floating things around
2833 // The membar serves as a pinch point between both control and all memory slices.
2834 Node* GraphKit::insert_mem_bar(int opcode, Node* precedent) {
2835   MemBarNode* mb = MemBarNode::make(C, opcode, Compile::AliasIdxBot, precedent);
2836   mb->init_req(TypeFunc::Control, control());
2837   mb->init_req(TypeFunc::Memory,  reset_memory());
2838   Node* membar = _gvn.transform(mb);
2839   set_control(_gvn.transform(new (C) ProjNode(membar, TypeFunc::Control)));
2840   set_all_memory_call(membar);
2841   return membar;
2842 }
2843 
2844 //-------------------------insert_mem_bar_volatile----------------------------
2845 // Memory barrier to avoid floating things around
2846 // The membar serves as a pinch point between both control and memory(alias_idx).
2847 // If you want to make a pinch point on all memory slices, do not use this
2848 // function (even with AliasIdxBot); use insert_mem_bar() instead.
2849 Node* GraphKit::insert_mem_bar_volatile(int opcode, int alias_idx, Node* precedent) {
2850   // When Parse::do_put_xxx updates a volatile field, it appends a series
2851   // of MemBarVolatile nodes, one for *each* volatile field alias category.
2852   // The first membar is on the same memory slice as the field store opcode.
2853   // This forces the membar to follow the store.  (Bug 6500685 broke this.)
2854   // All the other membars (for other volatile slices, including AliasIdxBot,
2855   // which stands for all unknown volatile slices) are control-dependent
2856   // on the first membar.  This prevents later volatile loads or stores
2857   // from sliding up past the just-emitted store.
2858 
2859   MemBarNode* mb = MemBarNode::make(C, opcode, alias_idx, precedent);
2860   mb->set_req(TypeFunc::Control,control());
2861   if (alias_idx == Compile::AliasIdxBot) {
2862     mb->set_req(TypeFunc::Memory, merged_memory()->base_memory());
2863   } else {
2864     assert(!(opcode == Op_Initialize && alias_idx != Compile::AliasIdxRaw), "fix caller");
2865     mb->set_req(TypeFunc::Memory, memory(alias_idx));
2866   }
2867   Node* membar = _gvn.transform(mb);
2868   set_control(_gvn.transform(new (C) ProjNode(membar, TypeFunc::Control)));
2869   if (alias_idx == Compile::AliasIdxBot) {
2870     merged_memory()->set_base_memory(_gvn.transform(new (C) ProjNode(membar, TypeFunc::Memory)));
2871   } else {
2872     set_memory(_gvn.transform(new (C) ProjNode(membar, TypeFunc::Memory)),alias_idx);
2873   }
2874   return membar;
2875 }
2876 
2877 //------------------------------shared_lock------------------------------------
2878 // Emit locking code.
2879 FastLockNode* GraphKit::shared_lock(Node* obj) {
2880   // bci is either a monitorenter bc or InvocationEntryBci
2881   // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
2882   assert(SynchronizationEntryBCI == InvocationEntryBci, "");
2883 
2884   if( !GenerateSynchronizationCode )
2885     return NULL;                // Not locking things?
2886   if (stopped())                // Dead monitor?
2887     return NULL;
2888 
2889   assert(dead_locals_are_killed(), "should kill locals before sync. point");
2890 
2891   // Box the stack location
2892   Node* box = _gvn.transform(new (C) BoxLockNode(next_monitor()));
2893   Node* mem = reset_memory();
2894 
2895   FastLockNode * flock = _gvn.transform(new (C) FastLockNode(0, obj, box) )->as_FastLock();
2896   if (PrintPreciseBiasedLockingStatistics) {
2897     // Create the counters for this fast lock.
2898     flock->create_lock_counter(sync_jvms()); // sync_jvms used to get current bci
2899   }
2900   // Add monitor to debug info for the slow path.  If we block inside the
2901   // slow path and de-opt, we need the monitor hanging around
2902   map()->push_monitor( flock );
2903 
2904   const TypeFunc *tf = LockNode::lock_type();
2905   LockNode *lock = new (C) LockNode(C, tf);
2906 
2907   lock->init_req( TypeFunc::Control, control() );
2908   lock->init_req( TypeFunc::Memory , mem );
2909   lock->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
2910   lock->init_req( TypeFunc::FramePtr, frameptr() );
2911   lock->init_req( TypeFunc::ReturnAdr, top() );
2912 
2913   lock->init_req(TypeFunc::Parms + 0, obj);
2914   lock->init_req(TypeFunc::Parms + 1, box);
2915   lock->init_req(TypeFunc::Parms + 2, flock);
2916   add_safepoint_edges(lock);
2917 
2918   lock = _gvn.transform( lock )->as_Lock();
2919 
2920   // lock has no side-effects, sets few values
2921   set_predefined_output_for_runtime_call(lock, mem, TypeRawPtr::BOTTOM);
2922 
2923   insert_mem_bar(Op_MemBarAcquireLock);
2924 
2925   // Add this to the worklist so that the lock can be eliminated
2926   record_for_igvn(lock);
2927 
2928 #ifndef PRODUCT
2929   if (PrintLockStatistics) {
2930     // Update the counter for this lock.  Don't bother using an atomic
2931     // operation since we don't require absolute accuracy.
2932     lock->create_lock_counter(map()->jvms());
2933     increment_counter(lock->counter()->addr());
2934   }
2935 #endif
2936 
2937   return flock;
2938 }
2939 
2940 
2941 //------------------------------shared_unlock----------------------------------
2942 // Emit unlocking code.
2943 void GraphKit::shared_unlock(Node* box, Node* obj) {
2944   // bci is either a monitorenter bc or InvocationEntryBci
2945   // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
2946   assert(SynchronizationEntryBCI == InvocationEntryBci, "");
2947 
2948   if( !GenerateSynchronizationCode )
2949     return;
2950   if (stopped()) {               // Dead monitor?
2951     map()->pop_monitor();        // Kill monitor from debug info
2952     return;
2953   }
2954 
2955   // Memory barrier to avoid floating things down past the locked region
2956   insert_mem_bar(Op_MemBarReleaseLock);
2957 
2958   const TypeFunc *tf = OptoRuntime::complete_monitor_exit_Type();
2959   UnlockNode *unlock = new (C) UnlockNode(C, tf);
2960   uint raw_idx = Compile::AliasIdxRaw;
2961   unlock->init_req( TypeFunc::Control, control() );
2962   unlock->init_req( TypeFunc::Memory , memory(raw_idx) );
2963   unlock->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
2964   unlock->init_req( TypeFunc::FramePtr, frameptr() );
2965   unlock->init_req( TypeFunc::ReturnAdr, top() );
2966 
2967   unlock->init_req(TypeFunc::Parms + 0, obj);
2968   unlock->init_req(TypeFunc::Parms + 1, box);
2969   unlock = _gvn.transform(unlock)->as_Unlock();
2970 
2971   Node* mem = reset_memory();
2972 
2973   // unlock has no side-effects, sets few values
2974   set_predefined_output_for_runtime_call(unlock, mem, TypeRawPtr::BOTTOM);
2975 
2976   // Kill monitor from debug info
2977   map()->pop_monitor( );
2978 }
2979 
2980 //-------------------------------get_layout_helper-----------------------------
2981 // If the given klass is a constant or known to be an array,
2982 // fetch the constant layout helper value into constant_value
2983 // and return (Node*)NULL.  Otherwise, load the non-constant
2984 // layout helper value, and return the node which represents it.
2985 // This two-faced routine is useful because allocation sites
2986 // almost always feature constant types.
2987 Node* GraphKit::get_layout_helper(Node* klass_node, jint& constant_value) {
2988   const TypeKlassPtr* inst_klass = _gvn.type(klass_node)->isa_klassptr();
2989   if (!StressReflectiveCode && inst_klass != NULL) {
2990     ciKlass* klass = inst_klass->klass();
2991     bool    xklass = inst_klass->klass_is_exact();
2992     if (xklass || klass->is_array_klass()) {
2993       jint lhelper = klass->layout_helper();
2994       if (lhelper != Klass::_lh_neutral_value) {
2995         constant_value = lhelper;
2996         return (Node*) NULL;
2997       }
2998     }
2999   }
3000   constant_value = Klass::_lh_neutral_value;  // put in a known value
3001   Node* lhp = basic_plus_adr(klass_node, klass_node, in_bytes(Klass::layout_helper_offset()));
3002   return make_load(NULL, lhp, TypeInt::INT, T_INT);
3003 }
3004 
3005 // We just put in an allocate/initialize with a big raw-memory effect.
3006 // Hook selected additional alias categories on the initialization.
3007 static void hook_memory_on_init(GraphKit& kit, int alias_idx,
3008                                 MergeMemNode* init_in_merge,
3009                                 Node* init_out_raw) {
3010   DEBUG_ONLY(Node* init_in_raw = init_in_merge->base_memory());
3011   assert(init_in_merge->memory_at(alias_idx) == init_in_raw, "");
3012 
3013   Node* prevmem = kit.memory(alias_idx);
3014   init_in_merge->set_memory_at(alias_idx, prevmem);
3015   kit.set_memory(init_out_raw, alias_idx);
3016 }
3017 
3018 //---------------------------set_output_for_allocation-------------------------
3019 Node* GraphKit::set_output_for_allocation(AllocateNode* alloc,
3020                                           const TypeOopPtr* oop_type) {
3021   int rawidx = Compile::AliasIdxRaw;
3022   alloc->set_req( TypeFunc::FramePtr, frameptr() );
3023   add_safepoint_edges(alloc);
3024   Node* allocx = _gvn.transform(alloc);
3025   set_control( _gvn.transform(new (C) ProjNode(allocx, TypeFunc::Control) ) );
3026   // create memory projection for i_o
3027   set_memory ( _gvn.transform( new (C) ProjNode(allocx, TypeFunc::Memory, true) ), rawidx );
3028   make_slow_call_ex(allocx, env()->Throwable_klass(), true);
3029 
3030   // create a memory projection as for the normal control path
3031   Node* malloc = _gvn.transform(new (C) ProjNode(allocx, TypeFunc::Memory));
3032   set_memory(malloc, rawidx);
3033 
3034   // a normal slow-call doesn't change i_o, but an allocation does
3035   // we create a separate i_o projection for the normal control path
3036   set_i_o(_gvn.transform( new (C) ProjNode(allocx, TypeFunc::I_O, false) ) );
3037   Node* rawoop = _gvn.transform( new (C) ProjNode(allocx, TypeFunc::Parms) );
3038 
3039   // put in an initialization barrier
3040   InitializeNode* init = insert_mem_bar_volatile(Op_Initialize, rawidx,
3041                                                  rawoop)->as_Initialize();
3042   assert(alloc->initialization() == init,  "2-way macro link must work");
3043   assert(init ->allocation()     == alloc, "2-way macro link must work");
3044   {
3045     // Extract memory strands which may participate in the new object's
3046     // initialization, and source them from the new InitializeNode.
3047     // This will allow us to observe initializations when they occur,
3048     // and link them properly (as a group) to the InitializeNode.
3049     assert(init->in(InitializeNode::Memory) == malloc, "");
3050     MergeMemNode* minit_in = MergeMemNode::make(C, malloc);
3051     init->set_req(InitializeNode::Memory, minit_in);
3052     record_for_igvn(minit_in); // fold it up later, if possible
3053     Node* minit_out = memory(rawidx);
3054     assert(minit_out->is_Proj() && minit_out->in(0) == init, "");
3055     if (oop_type->isa_aryptr()) {
3056       const TypePtr* telemref = oop_type->add_offset(Type::OffsetBot);
3057       int            elemidx  = C->get_alias_index(telemref);
3058       hook_memory_on_init(*this, elemidx, minit_in, minit_out);
3059     } else if (oop_type->isa_instptr()) {
3060       ciInstanceKlass* ik = oop_type->klass()->as_instance_klass();
3061       for (int i = 0, len = ik->nof_nonstatic_fields(); i < len; i++) {
3062         ciField* field = ik->nonstatic_field_at(i);
3063         if (field->offset() >= TrackedInitializationLimit * HeapWordSize)
3064           continue;  // do not bother to track really large numbers of fields
3065         // Find (or create) the alias category for this field:
3066         int fieldidx = C->alias_type(field)->index();
3067         hook_memory_on_init(*this, fieldidx, minit_in, minit_out);
3068       }
3069     }
3070   }
3071 
3072   // Cast raw oop to the real thing...
3073   Node* javaoop = new (C) CheckCastPPNode(control(), rawoop, oop_type);
3074   javaoop = _gvn.transform(javaoop);
3075   C->set_recent_alloc(control(), javaoop);
3076   assert(just_allocated_object(control()) == javaoop, "just allocated");
3077 
3078 #ifdef ASSERT
3079   { // Verify that the AllocateNode::Ideal_allocation recognizers work:
3080     assert(AllocateNode::Ideal_allocation(rawoop, &_gvn) == alloc,
3081            "Ideal_allocation works");
3082     assert(AllocateNode::Ideal_allocation(javaoop, &_gvn) == alloc,
3083            "Ideal_allocation works");
3084     if (alloc->is_AllocateArray()) {
3085       assert(AllocateArrayNode::Ideal_array_allocation(rawoop, &_gvn) == alloc->as_AllocateArray(),
3086              "Ideal_allocation works");
3087       assert(AllocateArrayNode::Ideal_array_allocation(javaoop, &_gvn) == alloc->as_AllocateArray(),
3088              "Ideal_allocation works");
3089     } else {
3090       assert(alloc->in(AllocateNode::ALength)->is_top(), "no length, please");
3091     }
3092   }
3093 #endif //ASSERT
3094 
3095   return javaoop;
3096 }
3097 
3098 //---------------------------new_instance--------------------------------------
3099 // This routine takes a klass_node which may be constant (for a static type)
3100 // or may be non-constant (for reflective code).  It will work equally well
3101 // for either, and the graph will fold nicely if the optimizer later reduces
3102 // the type to a constant.
3103 // The optional arguments are for specialized use by intrinsics:
3104 //  - If 'extra_slow_test' if not null is an extra condition for the slow-path.
3105 //  - If 'return_size_val', report the the total object size to the caller.
3106 Node* GraphKit::new_instance(Node* klass_node,
3107                              Node* extra_slow_test,
3108                              Node* *return_size_val) {
3109   // Compute size in doublewords
3110   // The size is always an integral number of doublewords, represented
3111   // as a positive bytewise size stored in the klass's layout_helper.
3112   // The layout_helper also encodes (in a low bit) the need for a slow path.
3113   jint  layout_con = Klass::_lh_neutral_value;
3114   Node* layout_val = get_layout_helper(klass_node, layout_con);
3115   int   layout_is_con = (layout_val == NULL);
3116 
3117   if (extra_slow_test == NULL)  extra_slow_test = intcon(0);
3118   // Generate the initial go-slow test.  It's either ALWAYS (return a
3119   // Node for 1) or NEVER (return a NULL) or perhaps (in the reflective
3120   // case) a computed value derived from the layout_helper.
3121   Node* initial_slow_test = NULL;
3122   if (layout_is_con) {
3123     assert(!StressReflectiveCode, "stress mode does not use these paths");
3124     bool must_go_slow = Klass::layout_helper_needs_slow_path(layout_con);
3125     initial_slow_test = must_go_slow? intcon(1): extra_slow_test;
3126 
3127   } else {   // reflective case
3128     // This reflective path is used by Unsafe.allocateInstance.
3129     // (It may be stress-tested by specifying StressReflectiveCode.)
3130     // Basically, we want to get into the VM is there's an illegal argument.
3131     Node* bit = intcon(Klass::_lh_instance_slow_path_bit);
3132     initial_slow_test = _gvn.transform( new (C) AndINode(layout_val, bit) );
3133     if (extra_slow_test != intcon(0)) {
3134       initial_slow_test = _gvn.transform( new (C) OrINode(initial_slow_test, extra_slow_test) );
3135     }
3136     // (Macro-expander will further convert this to a Bool, if necessary.)
3137   }
3138 
3139   // Find the size in bytes.  This is easy; it's the layout_helper.
3140   // The size value must be valid even if the slow path is taken.
3141   Node* size = NULL;
3142   if (layout_is_con) {
3143     size = MakeConX(Klass::layout_helper_size_in_bytes(layout_con));
3144   } else {   // reflective case
3145     // This reflective path is used by clone and Unsafe.allocateInstance.
3146     size = ConvI2X(layout_val);
3147 
3148     // Clear the low bits to extract layout_helper_size_in_bytes:
3149     assert((int)Klass::_lh_instance_slow_path_bit < BytesPerLong, "clear bit");
3150     Node* mask = MakeConX(~ (intptr_t)right_n_bits(LogBytesPerLong));
3151     size = _gvn.transform( new (C) AndXNode(size, mask) );
3152   }
3153   if (return_size_val != NULL) {
3154     (*return_size_val) = size;
3155   }
3156 
3157   // This is a precise notnull oop of the klass.
3158   // (Actually, it need not be precise if this is a reflective allocation.)
3159   // It's what we cast the result to.
3160   const TypeKlassPtr* tklass = _gvn.type(klass_node)->isa_klassptr();
3161   if (!tklass)  tklass = TypeKlassPtr::OBJECT;
3162   const TypeOopPtr* oop_type = tklass->as_instance_type();
3163 
3164   // Now generate allocation code
3165 
3166   // The entire memory state is needed for slow path of the allocation
3167   // since GC and deoptimization can happened.
3168   Node *mem = reset_memory();
3169   set_all_memory(mem); // Create new memory state
3170 
3171   AllocateNode* alloc
3172     = new (C) AllocateNode(C, AllocateNode::alloc_type(Type::TOP),
3173                            control(), mem, i_o(),
3174                            size, klass_node,
3175                            initial_slow_test);
3176 
3177   return set_output_for_allocation(alloc, oop_type);
3178 }
3179 
3180 //-------------------------------new_array-------------------------------------
3181 // helper for both newarray and anewarray
3182 // The 'length' parameter is (obviously) the length of the array.
3183 // See comments on new_instance for the meaning of the other arguments.
3184 Node* GraphKit::new_array(Node* klass_node,     // array klass (maybe variable)
3185                           Node* length,         // number of array elements
3186                           int   nargs,          // number of arguments to push back for uncommon trap
3187                           Node* *return_size_val) {
3188   jint  layout_con = Klass::_lh_neutral_value;
3189   Node* layout_val = get_layout_helper(klass_node, layout_con);
3190   int   layout_is_con = (layout_val == NULL);
3191 
3192   if (!layout_is_con && !StressReflectiveCode &&
3193       !too_many_traps(Deoptimization::Reason_class_check)) {
3194     // This is a reflective array creation site.
3195     // Optimistically assume that it is a subtype of Object[],
3196     // so that we can fold up all the address arithmetic.
3197     layout_con = Klass::array_layout_helper(T_OBJECT);
3198     Node* cmp_lh = _gvn.transform( new(C) CmpINode(layout_val, intcon(layout_con)) );
3199     Node* bol_lh = _gvn.transform( new(C) BoolNode(cmp_lh, BoolTest::eq) );
3200     { BuildCutout unless(this, bol_lh, PROB_MAX);
3201       inc_sp(nargs);
3202       uncommon_trap(Deoptimization::Reason_class_check,
3203                     Deoptimization::Action_maybe_recompile);
3204     }
3205     layout_val = NULL;
3206     layout_is_con = true;
3207   }
3208 
3209   // Generate the initial go-slow test.  Make sure we do not overflow
3210   // if length is huge (near 2Gig) or negative!  We do not need
3211   // exact double-words here, just a close approximation of needed
3212   // double-words.  We can't add any offset or rounding bits, lest we
3213   // take a size -1 of bytes and make it positive.  Use an unsigned
3214   // compare, so negative sizes look hugely positive.
3215   int fast_size_limit = FastAllocateSizeLimit;
3216   if (layout_is_con) {
3217     assert(!StressReflectiveCode, "stress mode does not use these paths");
3218     // Increase the size limit if we have exact knowledge of array type.
3219     int log2_esize = Klass::layout_helper_log2_element_size(layout_con);
3220     fast_size_limit <<= (LogBytesPerLong - log2_esize);
3221   }
3222 
3223   Node* initial_slow_cmp  = _gvn.transform( new (C) CmpUNode( length, intcon( fast_size_limit ) ) );
3224   Node* initial_slow_test = _gvn.transform( new (C) BoolNode( initial_slow_cmp, BoolTest::gt ) );
3225   if (initial_slow_test->is_Bool()) {
3226     // Hide it behind a CMoveI, or else PhaseIdealLoop::split_up will get sick.
3227     initial_slow_test = initial_slow_test->as_Bool()->as_int_value(&_gvn);
3228   }
3229 
3230   // --- Size Computation ---
3231   // array_size = round_to_heap(array_header + (length << elem_shift));
3232   // where round_to_heap(x) == round_to(x, MinObjAlignmentInBytes)
3233   // and round_to(x, y) == ((x + y-1) & ~(y-1))
3234   // The rounding mask is strength-reduced, if possible.
3235   int round_mask = MinObjAlignmentInBytes - 1;
3236   Node* header_size = NULL;
3237   int   header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
3238   // (T_BYTE has the weakest alignment and size restrictions...)
3239   if (layout_is_con) {
3240     int       hsize  = Klass::layout_helper_header_size(layout_con);
3241     int       eshift = Klass::layout_helper_log2_element_size(layout_con);
3242     BasicType etype  = Klass::layout_helper_element_type(layout_con);
3243     if ((round_mask & ~right_n_bits(eshift)) == 0)
3244       round_mask = 0;  // strength-reduce it if it goes away completely
3245     assert((hsize & right_n_bits(eshift)) == 0, "hsize is pre-rounded");
3246     assert(header_size_min <= hsize, "generic minimum is smallest");
3247     header_size_min = hsize;
3248     header_size = intcon(hsize + round_mask);
3249   } else {
3250     Node* hss   = intcon(Klass::_lh_header_size_shift);
3251     Node* hsm   = intcon(Klass::_lh_header_size_mask);
3252     Node* hsize = _gvn.transform( new(C) URShiftINode(layout_val, hss) );
3253     hsize       = _gvn.transform( new(C) AndINode(hsize, hsm) );
3254     Node* mask  = intcon(round_mask);
3255     header_size = _gvn.transform( new(C) AddINode(hsize, mask) );
3256   }
3257 
3258   Node* elem_shift = NULL;
3259   if (layout_is_con) {
3260     int eshift = Klass::layout_helper_log2_element_size(layout_con);
3261     if (eshift != 0)
3262       elem_shift = intcon(eshift);
3263   } else {
3264     // There is no need to mask or shift this value.
3265     // The semantics of LShiftINode include an implicit mask to 0x1F.
3266     assert(Klass::_lh_log2_element_size_shift == 0, "use shift in place");
3267     elem_shift = layout_val;
3268   }
3269 
3270   // Transition to native address size for all offset calculations:
3271   Node* lengthx = ConvI2X(length);
3272   Node* headerx = ConvI2X(header_size);
3273 #ifdef _LP64
3274   { const TypeLong* tllen = _gvn.find_long_type(lengthx);
3275     if (tllen != NULL && tllen->_lo < 0) {
3276       // Add a manual constraint to a positive range.  Cf. array_element_address.
3277       jlong size_max = arrayOopDesc::max_array_length(T_BYTE);
3278       if (size_max > tllen->_hi)  size_max = tllen->_hi;
3279       const TypeLong* tlcon = TypeLong::make(CONST64(0), size_max, Type::WidenMin);
3280       lengthx = _gvn.transform( new (C) ConvI2LNode(length, tlcon));
3281     }
3282   }
3283 #endif
3284 
3285   // Combine header size (plus rounding) and body size.  Then round down.
3286   // This computation cannot overflow, because it is used only in two
3287   // places, one where the length is sharply limited, and the other
3288   // after a successful allocation.
3289   Node* abody = lengthx;
3290   if (elem_shift != NULL)
3291     abody     = _gvn.transform( new(C) LShiftXNode(lengthx, elem_shift) );
3292   Node* size  = _gvn.transform( new(C) AddXNode(headerx, abody) );
3293   if (round_mask != 0) {
3294     Node* mask = MakeConX(~round_mask);
3295     size       = _gvn.transform( new(C) AndXNode(size, mask) );
3296   }
3297   // else if round_mask == 0, the size computation is self-rounding
3298 
3299   if (return_size_val != NULL) {
3300     // This is the size
3301     (*return_size_val) = size;
3302   }
3303 
3304   // Now generate allocation code
3305 
3306   // The entire memory state is needed for slow path of the allocation
3307   // since GC and deoptimization can happened.
3308   Node *mem = reset_memory();
3309   set_all_memory(mem); // Create new memory state
3310 
3311   // Create the AllocateArrayNode and its result projections
3312   AllocateArrayNode* alloc
3313     = new (C) AllocateArrayNode(C, AllocateArrayNode::alloc_type(TypeInt::INT),
3314                                 control(), mem, i_o(),
3315                                 size, klass_node,
3316                                 initial_slow_test,
3317                                 length);
3318 
3319   // Cast to correct type.  Note that the klass_node may be constant or not,
3320   // and in the latter case the actual array type will be inexact also.
3321   // (This happens via a non-constant argument to inline_native_newArray.)
3322   // In any case, the value of klass_node provides the desired array type.
3323   const TypeInt* length_type = _gvn.find_int_type(length);
3324   const TypeOopPtr* ary_type = _gvn.type(klass_node)->is_klassptr()->as_instance_type();
3325   if (ary_type->isa_aryptr() && length_type != NULL) {
3326     // Try to get a better type than POS for the size
3327     ary_type = ary_type->is_aryptr()->cast_to_size(length_type);
3328   }
3329 
3330   Node* javaoop = set_output_for_allocation(alloc, ary_type);
3331 
3332   // Cast length on remaining path to be as narrow as possible
3333   if (map()->find_edge(length) >= 0) {
3334     Node* ccast = alloc->make_ideal_length(ary_type, &_gvn);
3335     if (ccast != length) {
3336       _gvn.set_type_bottom(ccast);
3337       record_for_igvn(ccast);
3338       replace_in_map(length, ccast);
3339     }
3340   }
3341 
3342   return javaoop;
3343 }
3344 
3345 // The following "Ideal_foo" functions are placed here because they recognize
3346 // the graph shapes created by the functions immediately above.
3347 
3348 //---------------------------Ideal_allocation----------------------------------
3349 // Given an oop pointer or raw pointer, see if it feeds from an AllocateNode.
3350 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase) {
3351   if (ptr == NULL) {     // reduce dumb test in callers
3352     return NULL;
3353   }
3354   if (ptr->is_CheckCastPP()) { // strip only one raw-to-oop cast
3355     ptr = ptr->in(1);
3356     if (ptr == NULL) return NULL;
3357   }
3358   // Return NULL for allocations with several casts:
3359   //   j.l.reflect.Array.newInstance(jobject, jint)
3360   //   Object.clone()
3361   // to keep more precise type from last cast.
3362   if (ptr->is_Proj()) {
3363     Node* allo = ptr->in(0);
3364     if (allo != NULL && allo->is_Allocate()) {
3365       return allo->as_Allocate();
3366     }
3367   }
3368   // Report failure to match.
3369   return NULL;
3370 }
3371 
3372 // Fancy version which also strips off an offset (and reports it to caller).
3373 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase,
3374                                              intptr_t& offset) {
3375   Node* base = AddPNode::Ideal_base_and_offset(ptr, phase, offset);
3376   if (base == NULL)  return NULL;
3377   return Ideal_allocation(base, phase);
3378 }
3379 
3380 // Trace Initialize <- Proj[Parm] <- Allocate
3381 AllocateNode* InitializeNode::allocation() {
3382   Node* rawoop = in(InitializeNode::RawAddress);
3383   if (rawoop->is_Proj()) {
3384     Node* alloc = rawoop->in(0);
3385     if (alloc->is_Allocate()) {
3386       return alloc->as_Allocate();
3387     }
3388   }
3389   return NULL;
3390 }
3391 
3392 // Trace Allocate -> Proj[Parm] -> Initialize
3393 InitializeNode* AllocateNode::initialization() {
3394   ProjNode* rawoop = proj_out(AllocateNode::RawAddress);
3395   if (rawoop == NULL)  return NULL;
3396   for (DUIterator_Fast imax, i = rawoop->fast_outs(imax); i < imax; i++) {
3397     Node* init = rawoop->fast_out(i);
3398     if (init->is_Initialize()) {
3399       assert(init->as_Initialize()->allocation() == this, "2-way link");
3400       return init->as_Initialize();
3401     }
3402   }
3403   return NULL;
3404 }
3405 
3406 //----------------------------- loop predicates ---------------------------
3407 
3408 //------------------------------add_predicate_impl----------------------------
3409 void GraphKit::add_predicate_impl(Deoptimization::DeoptReason reason, int nargs) {
3410   // Too many traps seen?
3411   if (too_many_traps(reason)) {
3412 #ifdef ASSERT
3413     if (TraceLoopPredicate) {
3414       int tc = C->trap_count(reason);
3415       tty->print("too many traps=%s tcount=%d in ",
3416                     Deoptimization::trap_reason_name(reason), tc);
3417       method()->print(); // which method has too many predicate traps
3418       tty->cr();
3419     }
3420 #endif
3421     // We cannot afford to take more traps here,
3422     // do not generate predicate.
3423     return;
3424   }
3425 
3426   Node *cont    = _gvn.intcon(1);
3427   Node* opq     = _gvn.transform(new (C) Opaque1Node(C, cont));
3428   Node *bol     = _gvn.transform(new (C) Conv2BNode(opq));
3429   IfNode* iff   = create_and_map_if(control(), bol, PROB_MAX, COUNT_UNKNOWN);
3430   Node* iffalse = _gvn.transform(new (C) IfFalseNode(iff));
3431   C->add_predicate_opaq(opq);
3432   {
3433     PreserveJVMState pjvms(this);
3434     set_control(iffalse);
3435     inc_sp(nargs);
3436     uncommon_trap(reason, Deoptimization::Action_maybe_recompile);
3437   }
3438   Node* iftrue = _gvn.transform(new (C) IfTrueNode(iff));
3439   set_control(iftrue);
3440 }
3441 
3442 //------------------------------add_predicate---------------------------------
3443 void GraphKit::add_predicate(int nargs) {
3444   if (UseLoopPredicate) {
3445     add_predicate_impl(Deoptimization::Reason_predicate, nargs);
3446   }
3447   // loop's limit check predicate should be near the loop.
3448   if (LoopLimitCheck) {
3449     add_predicate_impl(Deoptimization::Reason_loop_limit_check, nargs);
3450   }
3451 }
3452 
3453 //----------------------------- store barriers ----------------------------
3454 #define __ ideal.
3455 
3456 void GraphKit::sync_kit(IdealKit& ideal) {
3457   set_all_memory(__ merged_memory());
3458   set_i_o(__ i_o());
3459   set_control(__ ctrl());
3460 }
3461 
3462 void GraphKit::final_sync(IdealKit& ideal) {
3463   // Final sync IdealKit and graphKit.
3464   sync_kit(ideal);
3465 }
3466 
3467 // vanilla/CMS post barrier
3468 // Insert a write-barrier store.  This is to let generational GC work; we have
3469 // to flag all oop-stores before the next GC point.
3470 void GraphKit::write_barrier_post(Node* oop_store,
3471                                   Node* obj,
3472                                   Node* adr,
3473                                   uint  adr_idx,
3474                                   Node* val,
3475                                   bool use_precise) {
3476   // No store check needed if we're storing a NULL or an old object
3477   // (latter case is probably a string constant). The concurrent
3478   // mark sweep garbage collector, however, needs to have all nonNull
3479   // oop updates flagged via card-marks.
3480   if (val != NULL && val->is_Con()) {
3481     // must be either an oop or NULL
3482     const Type* t = val->bottom_type();
3483     if (t == TypePtr::NULL_PTR || t == Type::TOP)
3484       // stores of null never (?) need barriers
3485       return;
3486   }
3487 
3488   if (use_ReduceInitialCardMarks()
3489       && obj == just_allocated_object(control())) {
3490     // We can skip marks on a freshly-allocated object in Eden.
3491     // Keep this code in sync with new_store_pre_barrier() in runtime.cpp.
3492     // That routine informs GC to take appropriate compensating steps,
3493     // upon a slow-path allocation, so as to make this card-mark
3494     // elision safe.
3495     return;
3496   }
3497 
3498   if (!use_precise) {
3499     // All card marks for a (non-array) instance are in one place:
3500     adr = obj;
3501   }
3502   // (Else it's an array (or unknown), and we want more precise card marks.)
3503   assert(adr != NULL, "");
3504 
3505   IdealKit ideal(this, true);
3506 
3507   // Convert the pointer to an int prior to doing math on it
3508   Node* cast = __ CastPX(__ ctrl(), adr);
3509 
3510   // Divide by card size
3511   assert(Universe::heap()->barrier_set()->kind() == BarrierSet::CardTableModRef,
3512          "Only one we handle so far.");
3513   Node* card_offset = __ URShiftX( cast, __ ConI(CardTableModRefBS::card_shift) );
3514 
3515   // Combine card table base and card offset
3516   Node* card_adr = __ AddP(__ top(), byte_map_base_node(), card_offset );
3517 
3518   // Get the alias_index for raw card-mark memory
3519   int adr_type = Compile::AliasIdxRaw;
3520   Node*   zero = __ ConI(0); // Dirty card value
3521   BasicType bt = T_BYTE;
3522 
3523   if (UseCondCardMark) {
3524     // The classic GC reference write barrier is typically implemented
3525     // as a store into the global card mark table.  Unfortunately
3526     // unconditional stores can result in false sharing and excessive
3527     // coherence traffic as well as false transactional aborts.
3528     // UseCondCardMark enables MP "polite" conditional card mark
3529     // stores.  In theory we could relax the load from ctrl() to
3530     // no_ctrl, but that doesn't buy much latitude.
3531     Node* card_val = __ load( __ ctrl(), card_adr, TypeInt::BYTE, bt, adr_type);
3532     __ if_then(card_val, BoolTest::ne, zero);
3533   }
3534 
3535   // Smash zero into card
3536   if( !UseConcMarkSweepGC ) {
3537     __ store(__ ctrl(), card_adr, zero, bt, adr_type);
3538   } else {
3539     // Specialized path for CM store barrier
3540     __ storeCM(__ ctrl(), card_adr, zero, oop_store, adr_idx, bt, adr_type);
3541   }
3542 
3543   if (UseCondCardMark) {
3544     __ end_if();
3545   }
3546 
3547   // Final sync IdealKit and GraphKit.
3548   final_sync(ideal);
3549 }
3550 
3551 // G1 pre/post barriers
3552 void GraphKit::g1_write_barrier_pre(bool do_load,
3553                                     Node* obj,
3554                                     Node* adr,
3555                                     uint alias_idx,
3556                                     Node* val,
3557                                     const TypeOopPtr* val_type,
3558                                     Node* pre_val,
3559                                     BasicType bt) {
3560 
3561   // Some sanity checks
3562   // Note: val is unused in this routine.
3563 
3564   if (do_load) {
3565     // We need to generate the load of the previous value
3566     assert(obj != NULL, "must have a base");
3567     assert(adr != NULL, "where are loading from?");
3568     assert(pre_val == NULL, "loaded already?");
3569     assert(val_type != NULL, "need a type");
3570   } else {
3571     // In this case both val_type and alias_idx are unused.
3572     assert(pre_val != NULL, "must be loaded already");
3573     // Nothing to be done if pre_val is null.
3574     if (pre_val->bottom_type() == TypePtr::NULL_PTR) return;
3575     assert(pre_val->bottom_type()->basic_type() == T_OBJECT, "or we shouldn't be here");
3576   }
3577   assert(bt == T_OBJECT, "or we shouldn't be here");
3578 
3579   IdealKit ideal(this, true);
3580 
3581   Node* tls = __ thread(); // ThreadLocalStorage
3582 
3583   Node* no_ctrl = NULL;
3584   Node* no_base = __ top();
3585   Node* zero  = __ ConI(0);
3586   Node* zeroX = __ ConX(0);
3587 
3588   float likely  = PROB_LIKELY(0.999);
3589   float unlikely  = PROB_UNLIKELY(0.999);
3590 
3591   BasicType active_type = in_bytes(PtrQueue::byte_width_of_active()) == 4 ? T_INT : T_BYTE;
3592   assert(in_bytes(PtrQueue::byte_width_of_active()) == 4 || in_bytes(PtrQueue::byte_width_of_active()) == 1, "flag width");
3593 
3594   // Offsets into the thread
3595   const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() +  // 648
3596                                           PtrQueue::byte_offset_of_active());
3597   const int index_offset   = in_bytes(JavaThread::satb_mark_queue_offset() +  // 656
3598                                           PtrQueue::byte_offset_of_index());
3599   const int buffer_offset  = in_bytes(JavaThread::satb_mark_queue_offset() +  // 652
3600                                           PtrQueue::byte_offset_of_buf());
3601 
3602   // Now the actual pointers into the thread
3603   Node* marking_adr = __ AddP(no_base, tls, __ ConX(marking_offset));
3604   Node* buffer_adr  = __ AddP(no_base, tls, __ ConX(buffer_offset));
3605   Node* index_adr   = __ AddP(no_base, tls, __ ConX(index_offset));
3606 
3607   // Now some of the values
3608   Node* marking = __ load(__ ctrl(), marking_adr, TypeInt::INT, active_type, Compile::AliasIdxRaw);
3609 
3610   // if (!marking)
3611   __ if_then(marking, BoolTest::ne, zero); {
3612     BasicType index_bt = TypeX_X->basic_type();
3613     assert(sizeof(size_t) == type2aelembytes(index_bt), "Loading G1 PtrQueue::_index with wrong size.");
3614     Node* index   = __ load(__ ctrl(), index_adr, TypeX_X, index_bt, Compile::AliasIdxRaw);
3615 
3616     if (do_load) {
3617       // load original value
3618       // alias_idx correct??
3619       pre_val = __ load(no_ctrl, adr, val_type, bt, alias_idx);
3620     }
3621 
3622     // if (pre_val != NULL)
3623     __ if_then(pre_val, BoolTest::ne, null()); {
3624       Node* buffer  = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
3625 
3626       // is the queue for this thread full?
3627       __ if_then(index, BoolTest::ne, zeroX, likely); {
3628 
3629         // decrement the index
3630         Node* next_index = _gvn.transform(new (C) SubXNode(index, __ ConX(sizeof(intptr_t))));
3631 
3632         // Now get the buffer location we will log the previous value into and store it
3633         Node *log_addr = __ AddP(no_base, buffer, next_index);
3634         __ store(__ ctrl(), log_addr, pre_val, T_OBJECT, Compile::AliasIdxRaw);
3635         // update the index
3636         __ store(__ ctrl(), index_adr, next_index, index_bt, Compile::AliasIdxRaw);
3637 
3638       } __ else_(); {
3639 
3640         // logging buffer is full, call the runtime
3641         const TypeFunc *tf = OptoRuntime::g1_wb_pre_Type();
3642         __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_pre), "g1_wb_pre", pre_val, tls);
3643       } __ end_if();  // (!index)
3644     } __ end_if();  // (pre_val != NULL)
3645   } __ end_if();  // (!marking)
3646 
3647   // Final sync IdealKit and GraphKit.
3648   final_sync(ideal);
3649 }
3650 
3651 //
3652 // Update the card table and add card address to the queue
3653 //
3654 void GraphKit::g1_mark_card(IdealKit& ideal,
3655                             Node* card_adr,
3656                             Node* oop_store,
3657                             uint oop_alias_idx,
3658                             Node* index,
3659                             Node* index_adr,
3660                             Node* buffer,
3661                             const TypeFunc* tf) {
3662 
3663   Node* zero  = __ ConI(0);
3664   Node* zeroX = __ ConX(0);
3665   Node* no_base = __ top();
3666   BasicType card_bt = T_BYTE;
3667   // Smash zero into card. MUST BE ORDERED WRT TO STORE
3668   __ storeCM(__ ctrl(), card_adr, zero, oop_store, oop_alias_idx, card_bt, Compile::AliasIdxRaw);
3669 
3670   //  Now do the queue work
3671   __ if_then(index, BoolTest::ne, zeroX); {
3672 
3673     Node* next_index = _gvn.transform(new (C) SubXNode(index, __ ConX(sizeof(intptr_t))));
3674     Node* log_addr = __ AddP(no_base, buffer, next_index);
3675 
3676     __ store(__ ctrl(), log_addr, card_adr, T_ADDRESS, Compile::AliasIdxRaw);
3677     __ store(__ ctrl(), index_adr, next_index, TypeX_X->basic_type(), Compile::AliasIdxRaw);
3678 
3679   } __ else_(); {
3680     __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_post), "g1_wb_post", card_adr, __ thread());
3681   } __ end_if();
3682 
3683 }
3684 
3685 void GraphKit::g1_write_barrier_post(Node* oop_store,
3686                                      Node* obj,
3687                                      Node* adr,
3688                                      uint alias_idx,
3689                                      Node* val,
3690                                      BasicType bt,
3691                                      bool use_precise) {
3692   // If we are writing a NULL then we need no post barrier
3693 
3694   if (val != NULL && val->is_Con() && val->bottom_type() == TypePtr::NULL_PTR) {
3695     // Must be NULL
3696     const Type* t = val->bottom_type();
3697     assert(t == Type::TOP || t == TypePtr::NULL_PTR, "must be NULL");
3698     // No post barrier if writing NULLx
3699     return;
3700   }
3701 
3702   if (!use_precise) {
3703     // All card marks for a (non-array) instance are in one place:
3704     adr = obj;
3705   }
3706   // (Else it's an array (or unknown), and we want more precise card marks.)
3707   assert(adr != NULL, "");
3708 
3709   IdealKit ideal(this, true);
3710 
3711   Node* tls = __ thread(); // ThreadLocalStorage
3712 
3713   Node* no_base = __ top();
3714   float likely  = PROB_LIKELY(0.999);
3715   float unlikely  = PROB_UNLIKELY(0.999);
3716   Node* zero = __ ConI(0);
3717   Node* zeroX = __ ConX(0);
3718 
3719   // Get the alias_index for raw card-mark memory
3720   const TypePtr* card_type = TypeRawPtr::BOTTOM;
3721 
3722   const TypeFunc *tf = OptoRuntime::g1_wb_post_Type();
3723 
3724   // Offsets into the thread
3725   const int index_offset  = in_bytes(JavaThread::dirty_card_queue_offset() +
3726                                      PtrQueue::byte_offset_of_index());
3727   const int buffer_offset = in_bytes(JavaThread::dirty_card_queue_offset() +
3728                                      PtrQueue::byte_offset_of_buf());
3729 
3730   // Pointers into the thread
3731 
3732   Node* buffer_adr = __ AddP(no_base, tls, __ ConX(buffer_offset));
3733   Node* index_adr =  __ AddP(no_base, tls, __ ConX(index_offset));
3734 
3735   // Now some values
3736   // Use ctrl to avoid hoisting these values past a safepoint, which could
3737   // potentially reset these fields in the JavaThread.
3738   Node* index  = __ load(__ ctrl(), index_adr, TypeX_X, TypeX_X->basic_type(), Compile::AliasIdxRaw);
3739   Node* buffer = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
3740 
3741   // Convert the store obj pointer to an int prior to doing math on it
3742   // Must use ctrl to prevent "integerized oop" existing across safepoint
3743   Node* cast =  __ CastPX(__ ctrl(), adr);
3744 
3745   // Divide pointer by card size
3746   Node* card_offset = __ URShiftX( cast, __ ConI(CardTableModRefBS::card_shift) );
3747 
3748   // Combine card table base and card offset
3749   Node* card_adr = __ AddP(no_base, byte_map_base_node(), card_offset );
3750 
3751   // If we know the value being stored does it cross regions?
3752 
3753   if (val != NULL) {
3754     // Does the store cause us to cross regions?
3755 
3756     // Should be able to do an unsigned compare of region_size instead of
3757     // and extra shift. Do we have an unsigned compare??
3758     // Node* region_size = __ ConI(1 << HeapRegion::LogOfHRGrainBytes);
3759     Node* xor_res =  __ URShiftX ( __ XorX( cast,  __ CastPX(__ ctrl(), val)), __ ConI(HeapRegion::LogOfHRGrainBytes));
3760 
3761     // if (xor_res == 0) same region so skip
3762     __ if_then(xor_res, BoolTest::ne, zeroX); {
3763 
3764       // No barrier if we are storing a NULL
3765       __ if_then(val, BoolTest::ne, null(), unlikely); {
3766 
3767         // Ok must mark the card if not already dirty
3768 
3769         // load the original value of the card
3770         Node* card_val = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
3771 
3772         __ if_then(card_val, BoolTest::ne, zero); {
3773           g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
3774         } __ end_if();
3775       } __ end_if();
3776     } __ end_if();
3777   } else {
3778     // Object.clone() instrinsic uses this path.
3779     g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
3780   }
3781 
3782   // Final sync IdealKit and GraphKit.
3783   final_sync(ideal);
3784 }
3785 #undef __
3786 
3787 
3788 
3789 Node* GraphKit::load_String_offset(Node* ctrl, Node* str) {
3790   if (java_lang_String::has_offset_field()) {
3791     int offset_offset = java_lang_String::offset_offset_in_bytes();
3792     const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
3793                                                        false, NULL, 0);
3794     const TypePtr* offset_field_type = string_type->add_offset(offset_offset);
3795     int offset_field_idx = C->get_alias_index(offset_field_type);
3796     return make_load(ctrl,
3797                      basic_plus_adr(str, str, offset_offset),
3798                      TypeInt::INT, T_INT, offset_field_idx);
3799   } else {
3800     return intcon(0);
3801   }
3802 }
3803 
3804 Node* GraphKit::load_String_length(Node* ctrl, Node* str) {
3805   if (java_lang_String::has_count_field()) {
3806     int count_offset = java_lang_String::count_offset_in_bytes();
3807     const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
3808                                                        false, NULL, 0);
3809     const TypePtr* count_field_type = string_type->add_offset(count_offset);
3810     int count_field_idx = C->get_alias_index(count_field_type);
3811     return make_load(ctrl,
3812                      basic_plus_adr(str, str, count_offset),
3813                      TypeInt::INT, T_INT, count_field_idx);
3814   } else {
3815     return load_array_length(load_String_value(ctrl, str));
3816   }
3817 }
3818 
3819 Node* GraphKit::load_String_value(Node* ctrl, Node* str) {
3820   int value_offset = java_lang_String::value_offset_in_bytes();
3821   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
3822                                                      false, NULL, 0);
3823   const TypePtr* value_field_type = string_type->add_offset(value_offset);
3824   const TypeAryPtr*  value_type = TypeAryPtr::make(TypePtr::NotNull,
3825                                                    TypeAry::make(TypeInt::CHAR,TypeInt::POS),
3826                                                    ciTypeArrayKlass::make(T_CHAR), true, 0);
3827   int value_field_idx = C->get_alias_index(value_field_type);
3828   return make_load(ctrl, basic_plus_adr(str, str, value_offset),
3829                    value_type, T_OBJECT, value_field_idx);
3830 }
3831 
3832 void GraphKit::store_String_offset(Node* ctrl, Node* str, Node* value) {
3833   int offset_offset = java_lang_String::offset_offset_in_bytes();
3834   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
3835                                                      false, NULL, 0);
3836   const TypePtr* offset_field_type = string_type->add_offset(offset_offset);
3837   int offset_field_idx = C->get_alias_index(offset_field_type);
3838   store_to_memory(ctrl, basic_plus_adr(str, offset_offset),
3839                   value, T_INT, offset_field_idx);
3840 }
3841 
3842 void GraphKit::store_String_value(Node* ctrl, Node* str, Node* value) {
3843   int value_offset = java_lang_String::value_offset_in_bytes();
3844   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
3845                                                      false, NULL, 0);
3846   const TypePtr* value_field_type = string_type->add_offset(value_offset);
3847   const TypeAryPtr*  value_type = TypeAryPtr::make(TypePtr::NotNull,
3848                                                    TypeAry::make(TypeInt::CHAR,TypeInt::POS),
3849                                                    ciTypeArrayKlass::make(T_CHAR), true, 0);
3850   int value_field_idx = C->get_alias_index(value_field_type);
3851   store_to_memory(ctrl, basic_plus_adr(str, value_offset),
3852                   value, T_OBJECT, value_field_idx);
3853 }
3854 
3855 void GraphKit::store_String_length(Node* ctrl, Node* str, Node* value) {
3856   int count_offset = java_lang_String::count_offset_in_bytes();
3857   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
3858                                                      false, NULL, 0);
3859   const TypePtr* count_field_type = string_type->add_offset(count_offset);
3860   int count_field_idx = C->get_alias_index(count_field_type);
3861   store_to_memory(ctrl, basic_plus_adr(str, count_offset),
3862                   value, T_INT, count_field_idx);
3863 }
--- EOF ---