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 void GraphKit::post_barrier(Node* ctl,
1505                             Node* store,
1506                             Node* obj,
1507                             Node* adr,
1508                             uint  adr_idx,
1509                             Node* val,
1510                             BasicType bt,
1511                             bool use_precise) {
1512   BarrierSet* bs = Universe::heap()->barrier_set();
1513   set_control(ctl);
1514   switch (bs->kind()) {
1515     case BarrierSet::G1SATBCT:
1516     case BarrierSet::G1SATBCTLogging:
1517       g1_write_barrier_post(store, obj, adr, adr_idx, val, bt, use_precise);
1518       break;
1519 
1520     case BarrierSet::CardTableModRef:
1521     case BarrierSet::CardTableExtension:
1522       write_barrier_post(store, obj, adr, adr_idx, val, use_precise);
1523       break;
1524 
1525     case BarrierSet::ModRef:
1526       break;
1527 
1528     case BarrierSet::Other:
1529     default      :
1530       ShouldNotReachHere();
1531 
1532   }
1533 }
1534 
1535 Node* GraphKit::store_oop(Node* ctl,
1536                           Node* obj,
1537                           Node* adr,
1538                           const TypePtr* adr_type,
1539                           Node* val,
1540                           const TypeOopPtr* val_type,
1541                           BasicType bt,
1542                           bool use_precise) {
1543   // Transformation of a value which could be NULL pointer (CastPP #NULL)
1544   // could be delayed during Parse (for example, in adjust_map_after_if()).
1545   // Execute transformation here to avoid barrier generation in such case.
1546   if (_gvn.type(val) == TypePtr::NULL_PTR)
1547     val = _gvn.makecon(TypePtr::NULL_PTR);
1548 
1549   set_control(ctl);
1550   if (stopped()) return top(); // Dead path ?
1551 
1552   assert(bt == T_OBJECT, "sanity");
1553   assert(val != NULL, "not dead path");
1554   uint adr_idx = C->get_alias_index(adr_type);
1555   assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
1556 
1557   pre_barrier(true /* do_load */,
1558               control(), obj, adr, adr_idx, val, val_type,
1559               NULL /* pre_val */,
1560               bt);
1561 
1562   Node* store = store_to_memory(control(), adr, val, bt, adr_idx);
1563   post_barrier(control(), store, obj, adr, adr_idx, val, bt, use_precise);
1564   return store;
1565 }
1566 
1567 // Could be an array or object we don't know at compile time (unsafe ref.)
1568 Node* GraphKit::store_oop_to_unknown(Node* ctl,
1569                              Node* obj,   // containing obj
1570                              Node* adr,  // actual adress to store val at
1571                              const TypePtr* adr_type,
1572                              Node* val,
1573                              BasicType bt) {
1574   Compile::AliasType* at = C->alias_type(adr_type);
1575   const TypeOopPtr* val_type = NULL;
1576   if (adr_type->isa_instptr()) {
1577     if (at->field() != NULL) {
1578       // known field.  This code is a copy of the do_put_xxx logic.
1579       ciField* field = at->field();
1580       if (!field->type()->is_loaded()) {
1581         val_type = TypeInstPtr::BOTTOM;
1582       } else {
1583         val_type = TypeOopPtr::make_from_klass(field->type()->as_klass());
1584       }
1585     }
1586   } else if (adr_type->isa_aryptr()) {
1587     val_type = adr_type->is_aryptr()->elem()->make_oopptr();
1588   }
1589   if (val_type == NULL) {
1590     val_type = TypeInstPtr::BOTTOM;
1591   }
1592   return store_oop(ctl, obj, adr, adr_type, val, val_type, bt, true);
1593 }
1594 
1595 
1596 //-------------------------array_element_address-------------------------
1597 Node* GraphKit::array_element_address(Node* ary, Node* idx, BasicType elembt,
1598                                       const TypeInt* sizetype) {
1599   uint shift  = exact_log2(type2aelembytes(elembt));
1600   uint header = arrayOopDesc::base_offset_in_bytes(elembt);
1601 
1602   // short-circuit a common case (saves lots of confusing waste motion)
1603   jint idx_con = find_int_con(idx, -1);
1604   if (idx_con >= 0) {
1605     intptr_t offset = header + ((intptr_t)idx_con << shift);
1606     return basic_plus_adr(ary, offset);
1607   }
1608 
1609   // must be correct type for alignment purposes
1610   Node* base  = basic_plus_adr(ary, header);
1611 #ifdef _LP64
1612   // The scaled index operand to AddP must be a clean 64-bit value.
1613   // Java allows a 32-bit int to be incremented to a negative
1614   // value, which appears in a 64-bit register as a large
1615   // positive number.  Using that large positive number as an
1616   // operand in pointer arithmetic has bad consequences.
1617   // On the other hand, 32-bit overflow is rare, and the possibility
1618   // can often be excluded, if we annotate the ConvI2L node with
1619   // a type assertion that its value is known to be a small positive
1620   // number.  (The prior range check has ensured this.)
1621   // This assertion is used by ConvI2LNode::Ideal.
1622   int index_max = max_jint - 1;  // array size is max_jint, index is one less
1623   if (sizetype != NULL)  index_max = sizetype->_hi - 1;
1624   const TypeLong* lidxtype = TypeLong::make(CONST64(0), index_max, Type::WidenMax);
1625   idx = _gvn.transform( new (C) ConvI2LNode(idx, lidxtype) );
1626 #endif
1627   Node* scale = _gvn.transform( new (C) LShiftXNode(idx, intcon(shift)) );
1628   return basic_plus_adr(ary, base, scale);
1629 }
1630 
1631 //-------------------------load_array_element-------------------------
1632 Node* GraphKit::load_array_element(Node* ctl, Node* ary, Node* idx, const TypeAryPtr* arytype) {
1633   const Type* elemtype = arytype->elem();
1634   BasicType elembt = elemtype->array_element_basic_type();
1635   Node* adr = array_element_address(ary, idx, elembt, arytype->size());
1636   Node* ld = make_load(ctl, adr, elemtype, elembt, arytype);
1637   return ld;
1638 }
1639 
1640 //-------------------------set_arguments_for_java_call-------------------------
1641 // Arguments (pre-popped from the stack) are taken from the JVMS.
1642 void GraphKit::set_arguments_for_java_call(CallJavaNode* call) {
1643   // Add the call arguments:
1644   uint nargs = call->method()->arg_size();
1645   for (uint i = 0; i < nargs; i++) {
1646     Node* arg = argument(i);
1647     call->init_req(i + TypeFunc::Parms, arg);
1648   }
1649 }
1650 
1651 //---------------------------set_edges_for_java_call---------------------------
1652 // Connect a newly created call into the current JVMS.
1653 // A return value node (if any) is returned from set_edges_for_java_call.
1654 void GraphKit::set_edges_for_java_call(CallJavaNode* call, bool must_throw, bool separate_io_proj) {
1655 
1656   // Add the predefined inputs:
1657   call->init_req( TypeFunc::Control, control() );
1658   call->init_req( TypeFunc::I_O    , i_o() );
1659   call->init_req( TypeFunc::Memory , reset_memory() );
1660   call->init_req( TypeFunc::FramePtr, frameptr() );
1661   call->init_req( TypeFunc::ReturnAdr, top() );
1662 
1663   add_safepoint_edges(call, must_throw);
1664 
1665   Node* xcall = _gvn.transform(call);
1666 
1667   if (xcall == top()) {
1668     set_control(top());
1669     return;
1670   }
1671   assert(xcall == call, "call identity is stable");
1672 
1673   // Re-use the current map to produce the result.
1674 
1675   set_control(_gvn.transform(new (C) ProjNode(call, TypeFunc::Control)));
1676   set_i_o(    _gvn.transform(new (C) ProjNode(call, TypeFunc::I_O    , separate_io_proj)));
1677   set_all_memory_call(xcall, separate_io_proj);
1678 
1679   //return xcall;   // no need, caller already has it
1680 }
1681 
1682 Node* GraphKit::set_results_for_java_call(CallJavaNode* call, bool separate_io_proj) {
1683   if (stopped())  return top();  // maybe the call folded up?
1684 
1685   // Capture the return value, if any.
1686   Node* ret;
1687   if (call->method() == NULL ||
1688       call->method()->return_type()->basic_type() == T_VOID)
1689         ret = top();
1690   else  ret = _gvn.transform(new (C) ProjNode(call, TypeFunc::Parms));
1691 
1692   // Note:  Since any out-of-line call can produce an exception,
1693   // we always insert an I_O projection from the call into the result.
1694 
1695   make_slow_call_ex(call, env()->Throwable_klass(), separate_io_proj);
1696 
1697   if (separate_io_proj) {
1698     // The caller requested separate projections be used by the fall
1699     // through and exceptional paths, so replace the projections for
1700     // the fall through path.
1701     set_i_o(_gvn.transform( new (C) ProjNode(call, TypeFunc::I_O) ));
1702     set_all_memory(_gvn.transform( new (C) ProjNode(call, TypeFunc::Memory) ));
1703   }
1704   return ret;
1705 }
1706 
1707 //--------------------set_predefined_input_for_runtime_call--------------------
1708 // Reading and setting the memory state is way conservative here.
1709 // The real problem is that I am not doing real Type analysis on memory,
1710 // so I cannot distinguish card mark stores from other stores.  Across a GC
1711 // point the Store Barrier and the card mark memory has to agree.  I cannot
1712 // have a card mark store and its barrier split across the GC point from
1713 // either above or below.  Here I get that to happen by reading ALL of memory.
1714 // A better answer would be to separate out card marks from other memory.
1715 // For now, return the input memory state, so that it can be reused
1716 // after the call, if this call has restricted memory effects.
1717 Node* GraphKit::set_predefined_input_for_runtime_call(SafePointNode* call) {
1718   // Set fixed predefined input arguments
1719   Node* memory = reset_memory();
1720   call->init_req( TypeFunc::Control,   control()  );
1721   call->init_req( TypeFunc::I_O,       top()      ); // does no i/o
1722   call->init_req( TypeFunc::Memory,    memory     ); // may gc ptrs
1723   call->init_req( TypeFunc::FramePtr,  frameptr() );
1724   call->init_req( TypeFunc::ReturnAdr, top()      );
1725   return memory;
1726 }
1727 
1728 //-------------------set_predefined_output_for_runtime_call--------------------
1729 // Set control and memory (not i_o) from the call.
1730 // If keep_mem is not NULL, use it for the output state,
1731 // except for the RawPtr output of the call, if hook_mem is TypeRawPtr::BOTTOM.
1732 // If hook_mem is NULL, this call produces no memory effects at all.
1733 // If hook_mem is a Java-visible memory slice (such as arraycopy operands),
1734 // then only that memory slice is taken from the call.
1735 // In the last case, we must put an appropriate memory barrier before
1736 // the call, so as to create the correct anti-dependencies on loads
1737 // preceding the call.
1738 void GraphKit::set_predefined_output_for_runtime_call(Node* call,
1739                                                       Node* keep_mem,
1740                                                       const TypePtr* hook_mem) {
1741   // no i/o
1742   set_control(_gvn.transform( new (C) ProjNode(call,TypeFunc::Control) ));
1743   if (keep_mem) {
1744     // First clone the existing memory state
1745     set_all_memory(keep_mem);
1746     if (hook_mem != NULL) {
1747       // Make memory for the call
1748       Node* mem = _gvn.transform( new (C) ProjNode(call, TypeFunc::Memory) );
1749       // Set the RawPtr memory state only.  This covers all the heap top/GC stuff
1750       // We also use hook_mem to extract specific effects from arraycopy stubs.
1751       set_memory(mem, hook_mem);
1752     }
1753     // ...else the call has NO memory effects.
1754 
1755     // Make sure the call advertises its memory effects precisely.
1756     // This lets us build accurate anti-dependences in gcm.cpp.
1757     assert(C->alias_type(call->adr_type()) == C->alias_type(hook_mem),
1758            "call node must be constructed correctly");
1759   } else {
1760     assert(hook_mem == NULL, "");
1761     // This is not a "slow path" call; all memory comes from the call.
1762     set_all_memory_call(call);
1763   }
1764 }
1765 
1766 
1767 // Replace the call with the current state of the kit.
1768 void GraphKit::replace_call(CallNode* call, Node* result) {
1769   JVMState* ejvms = NULL;
1770   if (has_exceptions()) {
1771     ejvms = transfer_exceptions_into_jvms();
1772   }
1773 
1774   SafePointNode* final_state = stop();
1775 
1776   // Find all the needed outputs of this call
1777   CallProjections callprojs;
1778   call->extract_projections(&callprojs, true);
1779 
1780   Node* init_mem = call->in(TypeFunc::Memory);
1781   Node* final_mem = final_state->in(TypeFunc::Memory);
1782   Node* final_ctl = final_state->in(TypeFunc::Control);
1783   Node* final_io = final_state->in(TypeFunc::I_O);
1784 
1785   // Replace all the old call edges with the edges from the inlining result
1786   if (callprojs.fallthrough_catchproj != NULL) {
1787     C->gvn_replace_by(callprojs.fallthrough_catchproj, final_ctl);
1788   }
1789   if (callprojs.fallthrough_memproj != NULL) {
1790     C->gvn_replace_by(callprojs.fallthrough_memproj,   final_mem);
1791   }
1792   if (callprojs.fallthrough_ioproj != NULL) {
1793     C->gvn_replace_by(callprojs.fallthrough_ioproj,    final_io);
1794   }
1795 
1796   // Replace the result with the new result if it exists and is used
1797   if (callprojs.resproj != NULL && result != NULL) {
1798     C->gvn_replace_by(callprojs.resproj, result);
1799   }
1800 
1801   if (ejvms == NULL) {
1802     // No exception edges to simply kill off those paths
1803     if (callprojs.catchall_catchproj != NULL) {
1804       C->gvn_replace_by(callprojs.catchall_catchproj, C->top());
1805     }
1806     if (callprojs.catchall_memproj != NULL) {
1807       C->gvn_replace_by(callprojs.catchall_memproj,   C->top());
1808     }
1809     if (callprojs.catchall_ioproj != NULL) {
1810       C->gvn_replace_by(callprojs.catchall_ioproj,    C->top());
1811     }
1812     // Replace the old exception object with top
1813     if (callprojs.exobj != NULL) {
1814       C->gvn_replace_by(callprojs.exobj, C->top());
1815     }
1816   } else {
1817     GraphKit ekit(ejvms);
1818 
1819     // Load my combined exception state into the kit, with all phis transformed:
1820     SafePointNode* ex_map = ekit.combine_and_pop_all_exception_states();
1821 
1822     Node* ex_oop = ekit.use_exception_state(ex_map);
1823     if (callprojs.catchall_catchproj != NULL) {
1824       C->gvn_replace_by(callprojs.catchall_catchproj, ekit.control());
1825     }
1826     if (callprojs.catchall_memproj != NULL) {
1827       C->gvn_replace_by(callprojs.catchall_memproj,   ekit.reset_memory());
1828     }
1829     if (callprojs.catchall_ioproj != NULL) {
1830       C->gvn_replace_by(callprojs.catchall_ioproj,    ekit.i_o());
1831     }
1832 
1833     // Replace the old exception object with the newly created one
1834     if (callprojs.exobj != NULL) {
1835       C->gvn_replace_by(callprojs.exobj, ex_oop);
1836     }
1837   }
1838 
1839   // Disconnect the call from the graph
1840   call->disconnect_inputs(NULL, C);
1841   C->gvn_replace_by(call, C->top());
1842 
1843   // Clean up any MergeMems that feed other MergeMems since the
1844   // optimizer doesn't like that.
1845   if (final_mem->is_MergeMem()) {
1846     Node_List wl;
1847     for (SimpleDUIterator i(final_mem); i.has_next(); i.next()) {
1848       Node* m = i.get();
1849       if (m->is_MergeMem() && !wl.contains(m)) {
1850         wl.push(m);
1851       }
1852     }
1853     while (wl.size()  > 0) {
1854       _gvn.transform(wl.pop());
1855     }
1856   }
1857 }
1858 
1859 
1860 //------------------------------increment_counter------------------------------
1861 // for statistics: increment a VM counter by 1
1862 
1863 void GraphKit::increment_counter(address counter_addr) {
1864   Node* adr1 = makecon(TypeRawPtr::make(counter_addr));
1865   increment_counter(adr1);
1866 }
1867 
1868 void GraphKit::increment_counter(Node* counter_addr) {
1869   int adr_type = Compile::AliasIdxRaw;
1870   Node* ctrl = control();
1871   Node* cnt  = make_load(ctrl, counter_addr, TypeInt::INT, T_INT, adr_type);
1872   Node* incr = _gvn.transform(new (C) AddINode(cnt, _gvn.intcon(1)));
1873   store_to_memory( ctrl, counter_addr, incr, T_INT, adr_type );
1874 }
1875 
1876 
1877 //------------------------------uncommon_trap----------------------------------
1878 // Bail out to the interpreter in mid-method.  Implemented by calling the
1879 // uncommon_trap blob.  This helper function inserts a runtime call with the
1880 // right debug info.
1881 void GraphKit::uncommon_trap(int trap_request,
1882                              ciKlass* klass, const char* comment,
1883                              bool must_throw,
1884                              bool keep_exact_action) {
1885   if (failing())  stop();
1886   if (stopped())  return; // trap reachable?
1887 
1888   // Note:  If ProfileTraps is true, and if a deopt. actually
1889   // occurs here, the runtime will make sure an MDO exists.  There is
1890   // no need to call method()->ensure_method_data() at this point.
1891 
1892   // Set the stack pointer to the right value for reexecution:
1893   set_sp(reexecute_sp());
1894 
1895 #ifdef ASSERT
1896   if (!must_throw) {
1897     // Make sure the stack has at least enough depth to execute
1898     // the current bytecode.
1899     int inputs, ignored_depth;
1900     if (compute_stack_effects(inputs, ignored_depth)) {
1901       assert(sp() >= inputs, err_msg_res("must have enough JVMS stack to execute %s: sp=%d, inputs=%d",
1902              Bytecodes::name(java_bc()), sp(), inputs));
1903     }
1904   }
1905 #endif
1906 
1907   Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(trap_request);
1908   Deoptimization::DeoptAction action = Deoptimization::trap_request_action(trap_request);
1909 
1910   switch (action) {
1911   case Deoptimization::Action_maybe_recompile:
1912   case Deoptimization::Action_reinterpret:
1913     // Temporary fix for 6529811 to allow virtual calls to be sure they
1914     // get the chance to go from mono->bi->mega
1915     if (!keep_exact_action &&
1916         Deoptimization::trap_request_index(trap_request) < 0 &&
1917         too_many_recompiles(reason)) {
1918       // This BCI is causing too many recompilations.
1919       action = Deoptimization::Action_none;
1920       trap_request = Deoptimization::make_trap_request(reason, action);
1921     } else {
1922       C->set_trap_can_recompile(true);
1923     }
1924     break;
1925   case Deoptimization::Action_make_not_entrant:
1926     C->set_trap_can_recompile(true);
1927     break;
1928 #ifdef ASSERT
1929   case Deoptimization::Action_none:
1930   case Deoptimization::Action_make_not_compilable:
1931     break;
1932   default:
1933     fatal(err_msg_res("unknown action %d: %s", action, Deoptimization::trap_action_name(action)));
1934     break;
1935 #endif
1936   }
1937 
1938   if (TraceOptoParse) {
1939     char buf[100];
1940     tty->print_cr("Uncommon trap %s at bci:%d",
1941                   Deoptimization::format_trap_request(buf, sizeof(buf),
1942                                                       trap_request), bci());
1943   }
1944 
1945   CompileLog* log = C->log();
1946   if (log != NULL) {
1947     int kid = (klass == NULL)? -1: log->identify(klass);
1948     log->begin_elem("uncommon_trap bci='%d'", bci());
1949     char buf[100];
1950     log->print(" %s", Deoptimization::format_trap_request(buf, sizeof(buf),
1951                                                           trap_request));
1952     if (kid >= 0)         log->print(" klass='%d'", kid);
1953     if (comment != NULL)  log->print(" comment='%s'", comment);
1954     log->end_elem();
1955   }
1956 
1957   // Make sure any guarding test views this path as very unlikely
1958   Node *i0 = control()->in(0);
1959   if (i0 != NULL && i0->is_If()) {        // Found a guarding if test?
1960     IfNode *iff = i0->as_If();
1961     float f = iff->_prob;   // Get prob
1962     if (control()->Opcode() == Op_IfTrue) {
1963       if (f > PROB_UNLIKELY_MAG(4))
1964         iff->_prob = PROB_MIN;
1965     } else {
1966       if (f < PROB_LIKELY_MAG(4))
1967         iff->_prob = PROB_MAX;
1968     }
1969   }
1970 
1971   // Clear out dead values from the debug info.
1972   kill_dead_locals();
1973 
1974   // Now insert the uncommon trap subroutine call
1975   address call_addr = SharedRuntime::uncommon_trap_blob()->entry_point();
1976   const TypePtr* no_memory_effects = NULL;
1977   // Pass the index of the class to be loaded
1978   Node* call = make_runtime_call(RC_NO_LEAF | RC_UNCOMMON |
1979                                  (must_throw ? RC_MUST_THROW : 0),
1980                                  OptoRuntime::uncommon_trap_Type(),
1981                                  call_addr, "uncommon_trap", no_memory_effects,
1982                                  intcon(trap_request));
1983   assert(call->as_CallStaticJava()->uncommon_trap_request() == trap_request,
1984          "must extract request correctly from the graph");
1985   assert(trap_request != 0, "zero value reserved by uncommon_trap_request");
1986 
1987   call->set_req(TypeFunc::ReturnAdr, returnadr());
1988   // The debug info is the only real input to this call.
1989 
1990   // Halt-and-catch fire here.  The above call should never return!
1991   HaltNode* halt = new(C) HaltNode(control(), frameptr());
1992   _gvn.set_type_bottom(halt);
1993   root()->add_req(halt);
1994 
1995   stop_and_kill_map();
1996 }
1997 
1998 
1999 //--------------------------just_allocated_object------------------------------
2000 // Report the object that was just allocated.
2001 // It must be the case that there are no intervening safepoints.
2002 // We use this to determine if an object is so "fresh" that
2003 // it does not require card marks.
2004 Node* GraphKit::just_allocated_object(Node* current_control) {
2005   if (C->recent_alloc_ctl() == current_control)
2006     return C->recent_alloc_obj();
2007   return NULL;
2008 }
2009 
2010 
2011 void GraphKit::round_double_arguments(ciMethod* dest_method) {
2012   // (Note:  TypeFunc::make has a cache that makes this fast.)
2013   const TypeFunc* tf    = TypeFunc::make(dest_method);
2014   int             nargs = tf->_domain->_cnt - TypeFunc::Parms;
2015   for (int j = 0; j < nargs; j++) {
2016     const Type *targ = tf->_domain->field_at(j + TypeFunc::Parms);
2017     if( targ->basic_type() == T_DOUBLE ) {
2018       // If any parameters are doubles, they must be rounded before
2019       // the call, dstore_rounding does gvn.transform
2020       Node *arg = argument(j);
2021       arg = dstore_rounding(arg);
2022       set_argument(j, arg);
2023     }
2024   }
2025 }
2026 
2027 void GraphKit::round_double_result(ciMethod* dest_method) {
2028   // A non-strict method may return a double value which has an extended
2029   // exponent, but this must not be visible in a caller which is 'strict'
2030   // If a strict caller invokes a non-strict callee, round a double result
2031 
2032   BasicType result_type = dest_method->return_type()->basic_type();
2033   assert( method() != NULL, "must have caller context");
2034   if( result_type == T_DOUBLE && method()->is_strict() && !dest_method->is_strict() ) {
2035     // Destination method's return value is on top of stack
2036     // dstore_rounding() does gvn.transform
2037     Node *result = pop_pair();
2038     result = dstore_rounding(result);
2039     push_pair(result);
2040   }
2041 }
2042 
2043 // rounding for strict float precision conformance
2044 Node* GraphKit::precision_rounding(Node* n) {
2045   return UseStrictFP && _method->flags().is_strict()
2046     && UseSSE == 0 && Matcher::strict_fp_requires_explicit_rounding
2047     ? _gvn.transform( new (C) RoundFloatNode(0, n) )
2048     : n;
2049 }
2050 
2051 // rounding for strict double precision conformance
2052 Node* GraphKit::dprecision_rounding(Node *n) {
2053   return UseStrictFP && _method->flags().is_strict()
2054     && UseSSE <= 1 && Matcher::strict_fp_requires_explicit_rounding
2055     ? _gvn.transform( new (C) RoundDoubleNode(0, n) )
2056     : n;
2057 }
2058 
2059 // rounding for non-strict double stores
2060 Node* GraphKit::dstore_rounding(Node* n) {
2061   return Matcher::strict_fp_requires_explicit_rounding
2062     && UseSSE <= 1
2063     ? _gvn.transform( new (C) RoundDoubleNode(0, n) )
2064     : n;
2065 }
2066 
2067 //=============================================================================
2068 // Generate a fast path/slow path idiom.  Graph looks like:
2069 // [foo] indicates that 'foo' is a parameter
2070 //
2071 //              [in]     NULL
2072 //                 \    /
2073 //                  CmpP
2074 //                  Bool ne
2075 //                   If
2076 //                  /  \
2077 //              True    False-<2>
2078 //              / |
2079 //             /  cast_not_null
2080 //           Load  |    |   ^
2081 //        [fast_test]   |   |
2082 // gvn to   opt_test    |   |
2083 //          /    \      |  <1>
2084 //      True     False  |
2085 //        |         \\  |
2086 //   [slow_call]     \[fast_result]
2087 //    Ctl   Val       \      \
2088 //     |               \      \
2089 //    Catch       <1>   \      \
2090 //   /    \        ^     \      \
2091 //  Ex    No_Ex    |      \      \
2092 //  |       \   \  |       \ <2>  \
2093 //  ...      \  [slow_res] |  |    \   [null_result]
2094 //            \         \--+--+---  |  |
2095 //             \           | /    \ | /
2096 //              --------Region     Phi
2097 //
2098 //=============================================================================
2099 // Code is structured as a series of driver functions all called 'do_XXX' that
2100 // call a set of helper functions.  Helper functions first, then drivers.
2101 
2102 //------------------------------null_check_oop---------------------------------
2103 // Null check oop.  Set null-path control into Region in slot 3.
2104 // Make a cast-not-nullness use the other not-null control.  Return cast.
2105 Node* GraphKit::null_check_oop(Node* value, Node* *null_control,
2106                                bool never_see_null) {
2107   // Initial NULL check taken path
2108   (*null_control) = top();
2109   Node* cast = null_check_common(value, T_OBJECT, false, null_control);
2110 
2111   // Generate uncommon_trap:
2112   if (never_see_null && (*null_control) != top()) {
2113     // If we see an unexpected null at a check-cast we record it and force a
2114     // recompile; the offending check-cast will be compiled to handle NULLs.
2115     // If we see more than one offending BCI, then all checkcasts in the
2116     // method will be compiled to handle NULLs.
2117     PreserveJVMState pjvms(this);
2118     set_control(*null_control);
2119     replace_in_map(value, null());
2120     uncommon_trap(Deoptimization::Reason_null_check,
2121                   Deoptimization::Action_make_not_entrant);
2122     (*null_control) = top();    // NULL path is dead
2123   }
2124 
2125   // Cast away null-ness on the result
2126   return cast;
2127 }
2128 
2129 //------------------------------opt_iff----------------------------------------
2130 // Optimize the fast-check IfNode.  Set the fast-path region slot 2.
2131 // Return slow-path control.
2132 Node* GraphKit::opt_iff(Node* region, Node* iff) {
2133   IfNode *opt_iff = _gvn.transform(iff)->as_If();
2134 
2135   // Fast path taken; set region slot 2
2136   Node *fast_taken = _gvn.transform( new (C) IfFalseNode(opt_iff) );
2137   region->init_req(2,fast_taken); // Capture fast-control
2138 
2139   // Fast path not-taken, i.e. slow path
2140   Node *slow_taken = _gvn.transform( new (C) IfTrueNode(opt_iff) );
2141   return slow_taken;
2142 }
2143 
2144 //-----------------------------make_runtime_call-------------------------------
2145 Node* GraphKit::make_runtime_call(int flags,
2146                                   const TypeFunc* call_type, address call_addr,
2147                                   const char* call_name,
2148                                   const TypePtr* adr_type,
2149                                   // The following parms are all optional.
2150                                   // The first NULL ends the list.
2151                                   Node* parm0, Node* parm1,
2152                                   Node* parm2, Node* parm3,
2153                                   Node* parm4, Node* parm5,
2154                                   Node* parm6, Node* parm7) {
2155   // Slow-path call
2156   bool is_leaf = !(flags & RC_NO_LEAF);
2157   bool has_io  = (!is_leaf && !(flags & RC_NO_IO));
2158   if (call_name == NULL) {
2159     assert(!is_leaf, "must supply name for leaf");
2160     call_name = OptoRuntime::stub_name(call_addr);
2161   }
2162   CallNode* call;
2163   if (!is_leaf) {
2164     call = new(C) CallStaticJavaNode(call_type, call_addr, call_name,
2165                                            bci(), adr_type);
2166   } else if (flags & RC_NO_FP) {
2167     call = new(C) CallLeafNoFPNode(call_type, call_addr, call_name, adr_type);
2168   } else {
2169     call = new(C) CallLeafNode(call_type, call_addr, call_name, adr_type);
2170   }
2171 
2172   // The following is similar to set_edges_for_java_call,
2173   // except that the memory effects of the call are restricted to AliasIdxRaw.
2174 
2175   // Slow path call has no side-effects, uses few values
2176   bool wide_in  = !(flags & RC_NARROW_MEM);
2177   bool wide_out = (C->get_alias_index(adr_type) == Compile::AliasIdxBot);
2178 
2179   Node* prev_mem = NULL;
2180   if (wide_in) {
2181     prev_mem = set_predefined_input_for_runtime_call(call);
2182   } else {
2183     assert(!wide_out, "narrow in => narrow out");
2184     Node* narrow_mem = memory(adr_type);
2185     prev_mem = reset_memory();
2186     map()->set_memory(narrow_mem);
2187     set_predefined_input_for_runtime_call(call);
2188   }
2189 
2190   // Hook each parm in order.  Stop looking at the first NULL.
2191   if (parm0 != NULL) { call->init_req(TypeFunc::Parms+0, parm0);
2192   if (parm1 != NULL) { call->init_req(TypeFunc::Parms+1, parm1);
2193   if (parm2 != NULL) { call->init_req(TypeFunc::Parms+2, parm2);
2194   if (parm3 != NULL) { call->init_req(TypeFunc::Parms+3, parm3);
2195   if (parm4 != NULL) { call->init_req(TypeFunc::Parms+4, parm4);
2196   if (parm5 != NULL) { call->init_req(TypeFunc::Parms+5, parm5);
2197   if (parm6 != NULL) { call->init_req(TypeFunc::Parms+6, parm6);
2198   if (parm7 != NULL) { call->init_req(TypeFunc::Parms+7, parm7);
2199     /* close each nested if ===> */  } } } } } } } }
2200   assert(call->in(call->req()-1) != NULL, "must initialize all parms");
2201 
2202   if (!is_leaf) {
2203     // Non-leaves can block and take safepoints:
2204     add_safepoint_edges(call, ((flags & RC_MUST_THROW) != 0));
2205   }
2206   // Non-leaves can throw exceptions:
2207   if (has_io) {
2208     call->set_req(TypeFunc::I_O, i_o());
2209   }
2210 
2211   if (flags & RC_UNCOMMON) {
2212     // Set the count to a tiny probability.  Cf. Estimate_Block_Frequency.
2213     // (An "if" probability corresponds roughly to an unconditional count.
2214     // Sort of.)
2215     call->set_cnt(PROB_UNLIKELY_MAG(4));
2216   }
2217 
2218   Node* c = _gvn.transform(call);
2219   assert(c == call, "cannot disappear");
2220 
2221   if (wide_out) {
2222     // Slow path call has full side-effects.
2223     set_predefined_output_for_runtime_call(call);
2224   } else {
2225     // Slow path call has few side-effects, and/or sets few values.
2226     set_predefined_output_for_runtime_call(call, prev_mem, adr_type);
2227   }
2228 
2229   if (has_io) {
2230     set_i_o(_gvn.transform(new (C) ProjNode(call, TypeFunc::I_O)));
2231   }
2232   return call;
2233 
2234 }
2235 
2236 //------------------------------merge_memory-----------------------------------
2237 // Merge memory from one path into the current memory state.
2238 void GraphKit::merge_memory(Node* new_mem, Node* region, int new_path) {
2239   for (MergeMemStream mms(merged_memory(), new_mem->as_MergeMem()); mms.next_non_empty2(); ) {
2240     Node* old_slice = mms.force_memory();
2241     Node* new_slice = mms.memory2();
2242     if (old_slice != new_slice) {
2243       PhiNode* phi;
2244       if (new_slice->is_Phi() && new_slice->as_Phi()->region() == region) {
2245         phi = new_slice->as_Phi();
2246         #ifdef ASSERT
2247         if (old_slice->is_Phi() && old_slice->as_Phi()->region() == region)
2248           old_slice = old_slice->in(new_path);
2249         // Caller is responsible for ensuring that any pre-existing
2250         // phis are already aware of old memory.
2251         int old_path = (new_path > 1) ? 1 : 2;  // choose old_path != new_path
2252         assert(phi->in(old_path) == old_slice, "pre-existing phis OK");
2253         #endif
2254         mms.set_memory(phi);
2255       } else {
2256         phi = PhiNode::make(region, old_slice, Type::MEMORY, mms.adr_type(C));
2257         _gvn.set_type(phi, Type::MEMORY);
2258         phi->set_req(new_path, new_slice);
2259         mms.set_memory(_gvn.transform(phi));  // assume it is complete
2260       }
2261     }
2262   }
2263 }
2264 
2265 //------------------------------make_slow_call_ex------------------------------
2266 // Make the exception handler hookups for the slow call
2267 void GraphKit::make_slow_call_ex(Node* call, ciInstanceKlass* ex_klass, bool separate_io_proj) {
2268   if (stopped())  return;
2269 
2270   // Make a catch node with just two handlers:  fall-through and catch-all
2271   Node* i_o  = _gvn.transform( new (C) ProjNode(call, TypeFunc::I_O, separate_io_proj) );
2272   Node* catc = _gvn.transform( new (C) CatchNode(control(), i_o, 2) );
2273   Node* norm = _gvn.transform( new (C) CatchProjNode(catc, CatchProjNode::fall_through_index, CatchProjNode::no_handler_bci) );
2274   Node* excp = _gvn.transform( new (C) CatchProjNode(catc, CatchProjNode::catch_all_index,    CatchProjNode::no_handler_bci) );
2275 
2276   { PreserveJVMState pjvms(this);
2277     set_control(excp);
2278     set_i_o(i_o);
2279 
2280     if (excp != top()) {
2281       // Create an exception state also.
2282       // Use an exact type if the caller has specified a specific exception.
2283       const Type* ex_type = TypeOopPtr::make_from_klass_unique(ex_klass)->cast_to_ptr_type(TypePtr::NotNull);
2284       Node*       ex_oop  = new (C) CreateExNode(ex_type, control(), i_o);
2285       add_exception_state(make_exception_state(_gvn.transform(ex_oop)));
2286     }
2287   }
2288 
2289   // Get the no-exception control from the CatchNode.
2290   set_control(norm);
2291 }
2292 
2293 
2294 //-------------------------------gen_subtype_check-----------------------------
2295 // Generate a subtyping check.  Takes as input the subtype and supertype.
2296 // Returns 2 values: sets the default control() to the true path and returns
2297 // the false path.  Only reads invariant memory; sets no (visible) memory.
2298 // The PartialSubtypeCheckNode sets the hidden 1-word cache in the encoding
2299 // but that's not exposed to the optimizer.  This call also doesn't take in an
2300 // Object; if you wish to check an Object you need to load the Object's class
2301 // prior to coming here.
2302 Node* GraphKit::gen_subtype_check(Node* subklass, Node* superklass) {
2303   // Fast check for identical types, perhaps identical constants.
2304   // The types can even be identical non-constants, in cases
2305   // involving Array.newInstance, Object.clone, etc.
2306   if (subklass == superklass)
2307     return top();             // false path is dead; no test needed.
2308 
2309   if (_gvn.type(superklass)->singleton()) {
2310     ciKlass* superk = _gvn.type(superklass)->is_klassptr()->klass();
2311     ciKlass* subk   = _gvn.type(subklass)->is_klassptr()->klass();
2312 
2313     // In the common case of an exact superklass, try to fold up the
2314     // test before generating code.  You may ask, why not just generate
2315     // the code and then let it fold up?  The answer is that the generated
2316     // code will necessarily include null checks, which do not always
2317     // completely fold away.  If they are also needless, then they turn
2318     // into a performance loss.  Example:
2319     //    Foo[] fa = blah(); Foo x = fa[0]; fa[1] = x;
2320     // Here, the type of 'fa' is often exact, so the store check
2321     // of fa[1]=x will fold up, without testing the nullness of x.
2322     switch (static_subtype_check(superk, subk)) {
2323     case SSC_always_false:
2324       {
2325         Node* always_fail = control();
2326         set_control(top());
2327         return always_fail;
2328       }
2329     case SSC_always_true:
2330       return top();
2331     case SSC_easy_test:
2332       {
2333         // Just do a direct pointer compare and be done.
2334         Node* cmp = _gvn.transform( new(C) CmpPNode(subklass, superklass) );
2335         Node* bol = _gvn.transform( new(C) BoolNode(cmp, BoolTest::eq) );
2336         IfNode* iff = create_and_xform_if(control(), bol, PROB_STATIC_FREQUENT, COUNT_UNKNOWN);
2337         set_control( _gvn.transform( new(C) IfTrueNode (iff) ) );
2338         return       _gvn.transform( new(C) IfFalseNode(iff) );
2339       }
2340     case SSC_full_test:
2341       break;
2342     default:
2343       ShouldNotReachHere();
2344     }
2345   }
2346 
2347   // %%% Possible further optimization:  Even if the superklass is not exact,
2348   // if the subklass is the unique subtype of the superklass, the check
2349   // will always succeed.  We could leave a dependency behind to ensure this.
2350 
2351   // First load the super-klass's check-offset
2352   Node *p1 = basic_plus_adr( superklass, superklass, in_bytes(Klass::super_check_offset_offset()) );
2353   Node *chk_off = _gvn.transform( new (C) LoadINode( NULL, memory(p1), p1, _gvn.type(p1)->is_ptr() ) );
2354   int cacheoff_con = in_bytes(Klass::secondary_super_cache_offset());
2355   bool might_be_cache = (find_int_con(chk_off, cacheoff_con) == cacheoff_con);
2356 
2357   // Load from the sub-klass's super-class display list, or a 1-word cache of
2358   // the secondary superclass list, or a failing value with a sentinel offset
2359   // if the super-klass is an interface or exceptionally deep in the Java
2360   // hierarchy and we have to scan the secondary superclass list the hard way.
2361   // Worst-case type is a little odd: NULL is allowed as a result (usually
2362   // klass loads can never produce a NULL).
2363   Node *chk_off_X = ConvI2X(chk_off);
2364   Node *p2 = _gvn.transform( new (C) AddPNode(subklass,subklass,chk_off_X) );
2365   // For some types like interfaces the following loadKlass is from a 1-word
2366   // cache which is mutable so can't use immutable memory.  Other
2367   // types load from the super-class display table which is immutable.
2368   Node *kmem = might_be_cache ? memory(p2) : immutable_memory();
2369   Node *nkls = _gvn.transform( LoadKlassNode::make( _gvn, kmem, p2, _gvn.type(p2)->is_ptr(), TypeKlassPtr::OBJECT_OR_NULL ) );
2370 
2371   // Compile speed common case: ARE a subtype and we canNOT fail
2372   if( superklass == nkls )
2373     return top();             // false path is dead; no test needed.
2374 
2375   // See if we get an immediate positive hit.  Happens roughly 83% of the
2376   // time.  Test to see if the value loaded just previously from the subklass
2377   // is exactly the superklass.
2378   Node *cmp1 = _gvn.transform( new (C) CmpPNode( superklass, nkls ) );
2379   Node *bol1 = _gvn.transform( new (C) BoolNode( cmp1, BoolTest::eq ) );
2380   IfNode *iff1 = create_and_xform_if( control(), bol1, PROB_LIKELY(0.83f), COUNT_UNKNOWN );
2381   Node *iftrue1 = _gvn.transform( new (C) IfTrueNode ( iff1 ) );
2382   set_control(    _gvn.transform( new (C) IfFalseNode( iff1 ) ) );
2383 
2384   // Compile speed common case: Check for being deterministic right now.  If
2385   // chk_off is a constant and not equal to cacheoff then we are NOT a
2386   // subklass.  In this case we need exactly the 1 test above and we can
2387   // return those results immediately.
2388   if (!might_be_cache) {
2389     Node* not_subtype_ctrl = control();
2390     set_control(iftrue1); // We need exactly the 1 test above
2391     return not_subtype_ctrl;
2392   }
2393 
2394   // Gather the various success & failures here
2395   RegionNode *r_ok_subtype = new (C) RegionNode(4);
2396   record_for_igvn(r_ok_subtype);
2397   RegionNode *r_not_subtype = new (C) RegionNode(3);
2398   record_for_igvn(r_not_subtype);
2399 
2400   r_ok_subtype->init_req(1, iftrue1);
2401 
2402   // Check for immediate negative hit.  Happens roughly 11% of the time (which
2403   // is roughly 63% of the remaining cases).  Test to see if the loaded
2404   // check-offset points into the subklass display list or the 1-element
2405   // cache.  If it points to the display (and NOT the cache) and the display
2406   // missed then it's not a subtype.
2407   Node *cacheoff = _gvn.intcon(cacheoff_con);
2408   Node *cmp2 = _gvn.transform( new (C) CmpINode( chk_off, cacheoff ) );
2409   Node *bol2 = _gvn.transform( new (C) BoolNode( cmp2, BoolTest::ne ) );
2410   IfNode *iff2 = create_and_xform_if( control(), bol2, PROB_LIKELY(0.63f), COUNT_UNKNOWN );
2411   r_not_subtype->init_req(1, _gvn.transform( new (C) IfTrueNode (iff2) ) );
2412   set_control(                _gvn.transform( new (C) IfFalseNode(iff2) ) );
2413 
2414   // Check for self.  Very rare to get here, but it is taken 1/3 the time.
2415   // No performance impact (too rare) but allows sharing of secondary arrays
2416   // which has some footprint reduction.
2417   Node *cmp3 = _gvn.transform( new (C) CmpPNode( subklass, superklass ) );
2418   Node *bol3 = _gvn.transform( new (C) BoolNode( cmp3, BoolTest::eq ) );
2419   IfNode *iff3 = create_and_xform_if( control(), bol3, PROB_LIKELY(0.36f), COUNT_UNKNOWN );
2420   r_ok_subtype->init_req(2, _gvn.transform( new (C) IfTrueNode ( iff3 ) ) );
2421   set_control(               _gvn.transform( new (C) IfFalseNode( iff3 ) ) );
2422 
2423   // -- Roads not taken here: --
2424   // We could also have chosen to perform the self-check at the beginning
2425   // of this code sequence, as the assembler does.  This would not pay off
2426   // the same way, since the optimizer, unlike the assembler, can perform
2427   // static type analysis to fold away many successful self-checks.
2428   // Non-foldable self checks work better here in second position, because
2429   // the initial primary superclass check subsumes a self-check for most
2430   // types.  An exception would be a secondary type like array-of-interface,
2431   // which does not appear in its own primary supertype display.
2432   // Finally, we could have chosen to move the self-check into the
2433   // PartialSubtypeCheckNode, and from there out-of-line in a platform
2434   // dependent manner.  But it is worthwhile to have the check here,
2435   // where it can be perhaps be optimized.  The cost in code space is
2436   // small (register compare, branch).
2437 
2438   // Now do a linear scan of the secondary super-klass array.  Again, no real
2439   // performance impact (too rare) but it's gotta be done.
2440   // Since the code is rarely used, there is no penalty for moving it
2441   // out of line, and it can only improve I-cache density.
2442   // The decision to inline or out-of-line this final check is platform
2443   // dependent, and is found in the AD file definition of PartialSubtypeCheck.
2444   Node* psc = _gvn.transform(
2445     new (C) PartialSubtypeCheckNode(control(), subklass, superklass) );
2446 
2447   Node *cmp4 = _gvn.transform( new (C) CmpPNode( psc, null() ) );
2448   Node *bol4 = _gvn.transform( new (C) BoolNode( cmp4, BoolTest::ne ) );
2449   IfNode *iff4 = create_and_xform_if( control(), bol4, PROB_FAIR, COUNT_UNKNOWN );
2450   r_not_subtype->init_req(2, _gvn.transform( new (C) IfTrueNode (iff4) ) );
2451   r_ok_subtype ->init_req(3, _gvn.transform( new (C) IfFalseNode(iff4) ) );
2452 
2453   // Return false path; set default control to true path.
2454   set_control( _gvn.transform(r_ok_subtype) );
2455   return _gvn.transform(r_not_subtype);
2456 }
2457 
2458 //----------------------------static_subtype_check-----------------------------
2459 // Shortcut important common cases when superklass is exact:
2460 // (0) superklass is java.lang.Object (can occur in reflective code)
2461 // (1) subklass is already limited to a subtype of superklass => always ok
2462 // (2) subklass does not overlap with superklass => always fail
2463 // (3) superklass has NO subtypes and we can check with a simple compare.
2464 int GraphKit::static_subtype_check(ciKlass* superk, ciKlass* subk) {
2465   if (StressReflectiveCode) {
2466     return SSC_full_test;       // Let caller generate the general case.
2467   }
2468 
2469   if (superk == env()->Object_klass()) {
2470     return SSC_always_true;     // (0) this test cannot fail
2471   }
2472 
2473   ciType* superelem = superk;
2474   if (superelem->is_array_klass())
2475     superelem = superelem->as_array_klass()->base_element_type();
2476 
2477   if (!subk->is_interface()) {  // cannot trust static interface types yet
2478     if (subk->is_subtype_of(superk)) {
2479       return SSC_always_true;   // (1) false path dead; no dynamic test needed
2480     }
2481     if (!(superelem->is_klass() && superelem->as_klass()->is_interface()) &&
2482         !superk->is_subtype_of(subk)) {
2483       return SSC_always_false;
2484     }
2485   }
2486 
2487   // If casting to an instance klass, it must have no subtypes
2488   if (superk->is_interface()) {
2489     // Cannot trust interfaces yet.
2490     // %%% S.B. superk->nof_implementors() == 1
2491   } else if (superelem->is_instance_klass()) {
2492     ciInstanceKlass* ik = superelem->as_instance_klass();
2493     if (!ik->has_subklass() && !ik->is_interface()) {
2494       if (!ik->is_final()) {
2495         // Add a dependency if there is a chance of a later subclass.
2496         C->dependencies()->assert_leaf_type(ik);
2497       }
2498       return SSC_easy_test;     // (3) caller can do a simple ptr comparison
2499     }
2500   } else {
2501     // A primitive array type has no subtypes.
2502     return SSC_easy_test;       // (3) caller can do a simple ptr comparison
2503   }
2504 
2505   return SSC_full_test;
2506 }
2507 
2508 // Profile-driven exact type check:
2509 Node* GraphKit::type_check_receiver(Node* receiver, ciKlass* klass,
2510                                     float prob,
2511                                     Node* *casted_receiver) {
2512   const TypeKlassPtr* tklass = TypeKlassPtr::make(klass);
2513   Node* recv_klass = load_object_klass(receiver);
2514   Node* want_klass = makecon(tklass);
2515   Node* cmp = _gvn.transform( new(C) CmpPNode(recv_klass, want_klass) );
2516   Node* bol = _gvn.transform( new(C) BoolNode(cmp, BoolTest::eq) );
2517   IfNode* iff = create_and_xform_if(control(), bol, prob, COUNT_UNKNOWN);
2518   set_control( _gvn.transform( new(C) IfTrueNode (iff) ));
2519   Node* fail = _gvn.transform( new(C) IfFalseNode(iff) );
2520 
2521   const TypeOopPtr* recv_xtype = tklass->as_instance_type();
2522   assert(recv_xtype->klass_is_exact(), "");
2523 
2524   // Subsume downstream occurrences of receiver with a cast to
2525   // recv_xtype, since now we know what the type will be.
2526   Node* cast = new(C) CheckCastPPNode(control(), receiver, recv_xtype);
2527   (*casted_receiver) = _gvn.transform(cast);
2528   // (User must make the replace_in_map call.)
2529 
2530   return fail;
2531 }
2532 
2533 
2534 //------------------------------seems_never_null-------------------------------
2535 // Use null_seen information if it is available from the profile.
2536 // If we see an unexpected null at a type check we record it and force a
2537 // recompile; the offending check will be recompiled to handle NULLs.
2538 // If we see several offending BCIs, then all checks in the
2539 // method will be recompiled.
2540 bool GraphKit::seems_never_null(Node* obj, ciProfileData* data) {
2541   if (UncommonNullCast               // Cutout for this technique
2542       && obj != null()               // And not the -Xcomp stupid case?
2543       && !too_many_traps(Deoptimization::Reason_null_check)
2544       ) {
2545     if (data == NULL)
2546       // Edge case:  no mature data.  Be optimistic here.
2547       return true;
2548     // If the profile has not seen a null, assume it won't happen.
2549     assert(java_bc() == Bytecodes::_checkcast ||
2550            java_bc() == Bytecodes::_instanceof ||
2551            java_bc() == Bytecodes::_aastore, "MDO must collect null_seen bit here");
2552     return !data->as_BitData()->null_seen();
2553   }
2554   return false;
2555 }
2556 
2557 //------------------------maybe_cast_profiled_receiver-------------------------
2558 // If the profile has seen exactly one type, narrow to exactly that type.
2559 // Subsequent type checks will always fold up.
2560 Node* GraphKit::maybe_cast_profiled_receiver(Node* not_null_obj,
2561                                              ciProfileData* data,
2562                                              ciKlass* require_klass) {
2563   if (!UseTypeProfile || !TypeProfileCasts) return NULL;
2564   if (data == NULL)  return NULL;
2565 
2566   // Make sure we haven't already deoptimized from this tactic.
2567   if (too_many_traps(Deoptimization::Reason_class_check))
2568     return NULL;
2569 
2570   // (No, this isn't a call, but it's enough like a virtual call
2571   // to use the same ciMethod accessor to get the profile info...)
2572   ciCallProfile profile = method()->call_profile_at_bci(bci());
2573   if (profile.count() >= 0 &&         // no cast failures here
2574       profile.has_receiver(0) &&
2575       profile.morphism() == 1) {
2576     ciKlass* exact_kls = profile.receiver(0);
2577     if (require_klass == NULL ||
2578         static_subtype_check(require_klass, exact_kls) == SSC_always_true) {
2579       // If we narrow the type to match what the type profile sees,
2580       // we can then remove the rest of the cast.
2581       // This is a win, even if the exact_kls is very specific,
2582       // because downstream operations, such as method calls,
2583       // will often benefit from the sharper type.
2584       Node* exact_obj = not_null_obj; // will get updated in place...
2585       Node* slow_ctl  = type_check_receiver(exact_obj, exact_kls, 1.0,
2586                                             &exact_obj);
2587       { PreserveJVMState pjvms(this);
2588         set_control(slow_ctl);
2589         uncommon_trap(Deoptimization::Reason_class_check,
2590                       Deoptimization::Action_maybe_recompile);
2591       }
2592       replace_in_map(not_null_obj, exact_obj);
2593       return exact_obj;
2594     }
2595     // assert(ssc == SSC_always_true)... except maybe the profile lied to us.
2596   }
2597 
2598   return NULL;
2599 }
2600 
2601 
2602 //-------------------------------gen_instanceof--------------------------------
2603 // Generate an instance-of idiom.  Used by both the instance-of bytecode
2604 // and the reflective instance-of call.
2605 Node* GraphKit::gen_instanceof(Node* obj, Node* superklass) {
2606   kill_dead_locals();           // Benefit all the uncommon traps
2607   assert( !stopped(), "dead parse path should be checked in callers" );
2608   assert(!TypePtr::NULL_PTR->higher_equal(_gvn.type(superklass)->is_klassptr()),
2609          "must check for not-null not-dead klass in callers");
2610 
2611   // Make the merge point
2612   enum { _obj_path = 1, _fail_path, _null_path, PATH_LIMIT };
2613   RegionNode* region = new(C) RegionNode(PATH_LIMIT);
2614   Node*       phi    = new(C) PhiNode(region, TypeInt::BOOL);
2615   C->set_has_split_ifs(true); // Has chance for split-if optimization
2616 
2617   ciProfileData* data = NULL;
2618   if (java_bc() == Bytecodes::_instanceof) {  // Only for the bytecode
2619     data = method()->method_data()->bci_to_data(bci());
2620   }
2621   bool never_see_null = (ProfileDynamicTypes  // aggressive use of profile
2622                          && seems_never_null(obj, data));
2623 
2624   // Null check; get casted pointer; set region slot 3
2625   Node* null_ctl = top();
2626   Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null);
2627 
2628   // If not_null_obj is dead, only null-path is taken
2629   if (stopped()) {              // Doing instance-of on a NULL?
2630     set_control(null_ctl);
2631     return intcon(0);
2632   }
2633   region->init_req(_null_path, null_ctl);
2634   phi   ->init_req(_null_path, intcon(0)); // Set null path value
2635   if (null_ctl == top()) {
2636     // Do this eagerly, so that pattern matches like is_diamond_phi
2637     // will work even during parsing.
2638     assert(_null_path == PATH_LIMIT-1, "delete last");
2639     region->del_req(_null_path);
2640     phi   ->del_req(_null_path);
2641   }
2642 
2643   if (ProfileDynamicTypes && data != NULL) {
2644     Node* cast_obj = maybe_cast_profiled_receiver(not_null_obj, data, NULL);
2645     if (stopped()) {            // Profile disagrees with this path.
2646       set_control(null_ctl);    // Null is the only remaining possibility.
2647       return intcon(0);
2648     }
2649     if (cast_obj != NULL)
2650       not_null_obj = cast_obj;
2651   }
2652 
2653   // Load the object's klass
2654   Node* obj_klass = load_object_klass(not_null_obj);
2655 
2656   // Generate the subtype check
2657   Node* not_subtype_ctrl = gen_subtype_check(obj_klass, superklass);
2658 
2659   // Plug in the success path to the general merge in slot 1.
2660   region->init_req(_obj_path, control());
2661   phi   ->init_req(_obj_path, intcon(1));
2662 
2663   // Plug in the failing path to the general merge in slot 2.
2664   region->init_req(_fail_path, not_subtype_ctrl);
2665   phi   ->init_req(_fail_path, intcon(0));
2666 
2667   // Return final merged results
2668   set_control( _gvn.transform(region) );
2669   record_for_igvn(region);
2670   return _gvn.transform(phi);
2671 }
2672 
2673 //-------------------------------gen_checkcast---------------------------------
2674 // Generate a checkcast idiom.  Used by both the checkcast bytecode and the
2675 // array store bytecode.  Stack must be as-if BEFORE doing the bytecode so the
2676 // uncommon-trap paths work.  Adjust stack after this call.
2677 // If failure_control is supplied and not null, it is filled in with
2678 // the control edge for the cast failure.  Otherwise, an appropriate
2679 // uncommon trap or exception is thrown.
2680 Node* GraphKit::gen_checkcast(Node *obj, Node* superklass,
2681                               Node* *failure_control) {
2682   kill_dead_locals();           // Benefit all the uncommon traps
2683   const TypeKlassPtr *tk = _gvn.type(superklass)->is_klassptr();
2684   const Type *toop = TypeOopPtr::make_from_klass(tk->klass());
2685 
2686   // Fast cutout:  Check the case that the cast is vacuously true.
2687   // This detects the common cases where the test will short-circuit
2688   // away completely.  We do this before we perform the null check,
2689   // because if the test is going to turn into zero code, we don't
2690   // want a residual null check left around.  (Causes a slowdown,
2691   // for example, in some objArray manipulations, such as a[i]=a[j].)
2692   if (tk->singleton()) {
2693     const TypeOopPtr* objtp = _gvn.type(obj)->isa_oopptr();
2694     if (objtp != NULL && objtp->klass() != NULL) {
2695       switch (static_subtype_check(tk->klass(), objtp->klass())) {
2696       case SSC_always_true:
2697         return obj;
2698       case SSC_always_false:
2699         // It needs a null check because a null will *pass* the cast check.
2700         // A non-null value will always produce an exception.
2701         return null_assert(obj);
2702       }
2703     }
2704   }
2705 
2706   ciProfileData* data = NULL;
2707   if (failure_control == NULL) {        // use MDO in regular case only
2708     assert(java_bc() == Bytecodes::_aastore ||
2709            java_bc() == Bytecodes::_checkcast,
2710            "interpreter profiles type checks only for these BCs");
2711     data = method()->method_data()->bci_to_data(bci());
2712   }
2713 
2714   // Make the merge point
2715   enum { _obj_path = 1, _null_path, PATH_LIMIT };
2716   RegionNode* region = new (C) RegionNode(PATH_LIMIT);
2717   Node*       phi    = new (C) PhiNode(region, toop);
2718   C->set_has_split_ifs(true); // Has chance for split-if optimization
2719 
2720   // Use null-cast information if it is available
2721   bool never_see_null = ((failure_control == NULL)  // regular case only
2722                          && seems_never_null(obj, data));
2723 
2724   // Null check; get casted pointer; set region slot 3
2725   Node* null_ctl = top();
2726   Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null);
2727 
2728   // If not_null_obj is dead, only null-path is taken
2729   if (stopped()) {              // Doing instance-of on a NULL?
2730     set_control(null_ctl);
2731     return null();
2732   }
2733   region->init_req(_null_path, null_ctl);
2734   phi   ->init_req(_null_path, null());  // Set null path value
2735   if (null_ctl == top()) {
2736     // Do this eagerly, so that pattern matches like is_diamond_phi
2737     // will work even during parsing.
2738     assert(_null_path == PATH_LIMIT-1, "delete last");
2739     region->del_req(_null_path);
2740     phi   ->del_req(_null_path);
2741   }
2742 
2743   Node* cast_obj = NULL;
2744   if (data != NULL &&
2745       // Counter has never been decremented (due to cast failure).
2746       // ...This is a reasonable thing to expect.  It is true of
2747       // all casts inserted by javac to implement generic types.
2748       data->as_CounterData()->count() >= 0) {
2749     cast_obj = maybe_cast_profiled_receiver(not_null_obj, data, tk->klass());
2750     if (cast_obj != NULL) {
2751       if (failure_control != NULL) // failure is now impossible
2752         (*failure_control) = top();
2753       // adjust the type of the phi to the exact klass:
2754       phi->raise_bottom_type(_gvn.type(cast_obj)->meet(TypePtr::NULL_PTR));
2755     }
2756   }
2757 
2758   if (cast_obj == NULL) {
2759     // Load the object's klass
2760     Node* obj_klass = load_object_klass(not_null_obj);
2761 
2762     // Generate the subtype check
2763     Node* not_subtype_ctrl = gen_subtype_check( obj_klass, superklass );
2764 
2765     // Plug in success path into the merge
2766     cast_obj = _gvn.transform(new (C) CheckCastPPNode(control(),
2767                                                          not_null_obj, toop));
2768     // Failure path ends in uncommon trap (or may be dead - failure impossible)
2769     if (failure_control == NULL) {
2770       if (not_subtype_ctrl != top()) { // If failure is possible
2771         PreserveJVMState pjvms(this);
2772         set_control(not_subtype_ctrl);
2773         builtin_throw(Deoptimization::Reason_class_check, obj_klass);
2774       }
2775     } else {
2776       (*failure_control) = not_subtype_ctrl;
2777     }
2778   }
2779 
2780   region->init_req(_obj_path, control());
2781   phi   ->init_req(_obj_path, cast_obj);
2782 
2783   // A merge of NULL or Casted-NotNull obj
2784   Node* res = _gvn.transform(phi);
2785 
2786   // Note I do NOT always 'replace_in_map(obj,result)' here.
2787   //  if( tk->klass()->can_be_primary_super()  )
2788     // This means that if I successfully store an Object into an array-of-String
2789     // I 'forget' that the Object is really now known to be a String.  I have to
2790     // do this because we don't have true union types for interfaces - if I store
2791     // a Baz into an array-of-Interface and then tell the optimizer it's an
2792     // Interface, I forget that it's also a Baz and cannot do Baz-like field
2793     // references to it.  FIX THIS WHEN UNION TYPES APPEAR!
2794   //  replace_in_map( obj, res );
2795 
2796   // Return final merged results
2797   set_control( _gvn.transform(region) );
2798   record_for_igvn(region);
2799   return res;
2800 }
2801 
2802 //------------------------------next_monitor-----------------------------------
2803 // What number should be given to the next monitor?
2804 int GraphKit::next_monitor() {
2805   int current = jvms()->monitor_depth()* C->sync_stack_slots();
2806   int next = current + C->sync_stack_slots();
2807   // Keep the toplevel high water mark current:
2808   if (C->fixed_slots() < next)  C->set_fixed_slots(next);
2809   return current;
2810 }
2811 
2812 //------------------------------insert_mem_bar---------------------------------
2813 // Memory barrier to avoid floating things around
2814 // The membar serves as a pinch point between both control and all memory slices.
2815 Node* GraphKit::insert_mem_bar(int opcode, Node* precedent) {
2816   MemBarNode* mb = MemBarNode::make(C, opcode, Compile::AliasIdxBot, precedent);
2817   mb->init_req(TypeFunc::Control, control());
2818   mb->init_req(TypeFunc::Memory,  reset_memory());
2819   Node* membar = _gvn.transform(mb);
2820   set_control(_gvn.transform(new (C) ProjNode(membar, TypeFunc::Control)));
2821   set_all_memory_call(membar);
2822   return membar;
2823 }
2824 
2825 //-------------------------insert_mem_bar_volatile----------------------------
2826 // Memory barrier to avoid floating things around
2827 // The membar serves as a pinch point between both control and memory(alias_idx).
2828 // If you want to make a pinch point on all memory slices, do not use this
2829 // function (even with AliasIdxBot); use insert_mem_bar() instead.
2830 Node* GraphKit::insert_mem_bar_volatile(int opcode, int alias_idx, Node* precedent) {
2831   // When Parse::do_put_xxx updates a volatile field, it appends a series
2832   // of MemBarVolatile nodes, one for *each* volatile field alias category.
2833   // The first membar is on the same memory slice as the field store opcode.
2834   // This forces the membar to follow the store.  (Bug 6500685 broke this.)
2835   // All the other membars (for other volatile slices, including AliasIdxBot,
2836   // which stands for all unknown volatile slices) are control-dependent
2837   // on the first membar.  This prevents later volatile loads or stores
2838   // from sliding up past the just-emitted store.
2839 
2840   MemBarNode* mb = MemBarNode::make(C, opcode, alias_idx, precedent);
2841   mb->set_req(TypeFunc::Control,control());
2842   if (alias_idx == Compile::AliasIdxBot) {
2843     mb->set_req(TypeFunc::Memory, merged_memory()->base_memory());
2844   } else {
2845     assert(!(opcode == Op_Initialize && alias_idx != Compile::AliasIdxRaw), "fix caller");
2846     mb->set_req(TypeFunc::Memory, memory(alias_idx));
2847   }
2848   Node* membar = _gvn.transform(mb);
2849   set_control(_gvn.transform(new (C) ProjNode(membar, TypeFunc::Control)));
2850   if (alias_idx == Compile::AliasIdxBot) {
2851     merged_memory()->set_base_memory(_gvn.transform(new (C) ProjNode(membar, TypeFunc::Memory)));
2852   } else {
2853     set_memory(_gvn.transform(new (C) ProjNode(membar, TypeFunc::Memory)),alias_idx);
2854   }
2855   return membar;
2856 }
2857 
2858 //------------------------------shared_lock------------------------------------
2859 // Emit locking code.
2860 FastLockNode* GraphKit::shared_lock(Node* obj) {
2861   // bci is either a monitorenter bc or InvocationEntryBci
2862   // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
2863   assert(SynchronizationEntryBCI == InvocationEntryBci, "");
2864 
2865   if( !GenerateSynchronizationCode )
2866     return NULL;                // Not locking things?
2867   if (stopped())                // Dead monitor?
2868     return NULL;
2869 
2870   assert(dead_locals_are_killed(), "should kill locals before sync. point");
2871 
2872   // Box the stack location
2873   Node* box = _gvn.transform(new (C) BoxLockNode(next_monitor()));
2874   Node* mem = reset_memory();
2875 
2876   FastLockNode * flock = _gvn.transform(new (C) FastLockNode(0, obj, box) )->as_FastLock();
2877   if (PrintPreciseBiasedLockingStatistics) {
2878     // Create the counters for this fast lock.
2879     flock->create_lock_counter(sync_jvms()); // sync_jvms used to get current bci
2880   }
2881   // Add monitor to debug info for the slow path.  If we block inside the
2882   // slow path and de-opt, we need the monitor hanging around
2883   map()->push_monitor( flock );
2884 
2885   const TypeFunc *tf = LockNode::lock_type();
2886   LockNode *lock = new (C) LockNode(C, tf);
2887 
2888   lock->init_req( TypeFunc::Control, control() );
2889   lock->init_req( TypeFunc::Memory , mem );
2890   lock->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
2891   lock->init_req( TypeFunc::FramePtr, frameptr() );
2892   lock->init_req( TypeFunc::ReturnAdr, top() );
2893 
2894   lock->init_req(TypeFunc::Parms + 0, obj);
2895   lock->init_req(TypeFunc::Parms + 1, box);
2896   lock->init_req(TypeFunc::Parms + 2, flock);
2897   add_safepoint_edges(lock);
2898 
2899   lock = _gvn.transform( lock )->as_Lock();
2900 
2901   // lock has no side-effects, sets few values
2902   set_predefined_output_for_runtime_call(lock, mem, TypeRawPtr::BOTTOM);
2903 
2904   insert_mem_bar(Op_MemBarAcquireLock);
2905 
2906   // Add this to the worklist so that the lock can be eliminated
2907   record_for_igvn(lock);
2908 
2909 #ifndef PRODUCT
2910   if (PrintLockStatistics) {
2911     // Update the counter for this lock.  Don't bother using an atomic
2912     // operation since we don't require absolute accuracy.
2913     lock->create_lock_counter(map()->jvms());
2914     increment_counter(lock->counter()->addr());
2915   }
2916 #endif
2917 
2918   return flock;
2919 }
2920 
2921 
2922 //------------------------------shared_unlock----------------------------------
2923 // Emit unlocking code.
2924 void GraphKit::shared_unlock(Node* box, Node* obj) {
2925   // bci is either a monitorenter bc or InvocationEntryBci
2926   // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
2927   assert(SynchronizationEntryBCI == InvocationEntryBci, "");
2928 
2929   if( !GenerateSynchronizationCode )
2930     return;
2931   if (stopped()) {               // Dead monitor?
2932     map()->pop_monitor();        // Kill monitor from debug info
2933     return;
2934   }
2935 
2936   // Memory barrier to avoid floating things down past the locked region
2937   insert_mem_bar(Op_MemBarReleaseLock);
2938 
2939   const TypeFunc *tf = OptoRuntime::complete_monitor_exit_Type();
2940   UnlockNode *unlock = new (C) UnlockNode(C, tf);
2941   uint raw_idx = Compile::AliasIdxRaw;
2942   unlock->init_req( TypeFunc::Control, control() );
2943   unlock->init_req( TypeFunc::Memory , memory(raw_idx) );
2944   unlock->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
2945   unlock->init_req( TypeFunc::FramePtr, frameptr() );
2946   unlock->init_req( TypeFunc::ReturnAdr, top() );
2947 
2948   unlock->init_req(TypeFunc::Parms + 0, obj);
2949   unlock->init_req(TypeFunc::Parms + 1, box);
2950   unlock = _gvn.transform(unlock)->as_Unlock();
2951 
2952   Node* mem = reset_memory();
2953 
2954   // unlock has no side-effects, sets few values
2955   set_predefined_output_for_runtime_call(unlock, mem, TypeRawPtr::BOTTOM);
2956 
2957   // Kill monitor from debug info
2958   map()->pop_monitor( );
2959 }
2960 
2961 //-------------------------------get_layout_helper-----------------------------
2962 // If the given klass is a constant or known to be an array,
2963 // fetch the constant layout helper value into constant_value
2964 // and return (Node*)NULL.  Otherwise, load the non-constant
2965 // layout helper value, and return the node which represents it.
2966 // This two-faced routine is useful because allocation sites
2967 // almost always feature constant types.
2968 Node* GraphKit::get_layout_helper(Node* klass_node, jint& constant_value) {
2969   const TypeKlassPtr* inst_klass = _gvn.type(klass_node)->isa_klassptr();
2970   if (!StressReflectiveCode && inst_klass != NULL) {
2971     ciKlass* klass = inst_klass->klass();
2972     bool    xklass = inst_klass->klass_is_exact();
2973     if (xklass || klass->is_array_klass()) {
2974       jint lhelper = klass->layout_helper();
2975       if (lhelper != Klass::_lh_neutral_value) {
2976         constant_value = lhelper;
2977         return (Node*) NULL;
2978       }
2979     }
2980   }
2981   constant_value = Klass::_lh_neutral_value;  // put in a known value
2982   Node* lhp = basic_plus_adr(klass_node, klass_node, in_bytes(Klass::layout_helper_offset()));
2983   return make_load(NULL, lhp, TypeInt::INT, T_INT);
2984 }
2985 
2986 // We just put in an allocate/initialize with a big raw-memory effect.
2987 // Hook selected additional alias categories on the initialization.
2988 static void hook_memory_on_init(GraphKit& kit, int alias_idx,
2989                                 MergeMemNode* init_in_merge,
2990                                 Node* init_out_raw) {
2991   DEBUG_ONLY(Node* init_in_raw = init_in_merge->base_memory());
2992   assert(init_in_merge->memory_at(alias_idx) == init_in_raw, "");
2993 
2994   Node* prevmem = kit.memory(alias_idx);
2995   init_in_merge->set_memory_at(alias_idx, prevmem);
2996   kit.set_memory(init_out_raw, alias_idx);
2997 }
2998 
2999 //---------------------------set_output_for_allocation-------------------------
3000 Node* GraphKit::set_output_for_allocation(AllocateNode* alloc,
3001                                           const TypeOopPtr* oop_type) {
3002   int rawidx = Compile::AliasIdxRaw;
3003   alloc->set_req( TypeFunc::FramePtr, frameptr() );
3004   add_safepoint_edges(alloc);
3005   Node* allocx = _gvn.transform(alloc);
3006   set_control( _gvn.transform(new (C) ProjNode(allocx, TypeFunc::Control) ) );
3007   // create memory projection for i_o
3008   set_memory ( _gvn.transform( new (C) ProjNode(allocx, TypeFunc::Memory, true) ), rawidx );
3009   make_slow_call_ex(allocx, env()->Throwable_klass(), true);
3010 
3011   // create a memory projection as for the normal control path
3012   Node* malloc = _gvn.transform(new (C) ProjNode(allocx, TypeFunc::Memory));
3013   set_memory(malloc, rawidx);
3014 
3015   // a normal slow-call doesn't change i_o, but an allocation does
3016   // we create a separate i_o projection for the normal control path
3017   set_i_o(_gvn.transform( new (C) ProjNode(allocx, TypeFunc::I_O, false) ) );
3018   Node* rawoop = _gvn.transform( new (C) ProjNode(allocx, TypeFunc::Parms) );
3019 
3020   // put in an initialization barrier
3021   InitializeNode* init = insert_mem_bar_volatile(Op_Initialize, rawidx,
3022                                                  rawoop)->as_Initialize();
3023   assert(alloc->initialization() == init,  "2-way macro link must work");
3024   assert(init ->allocation()     == alloc, "2-way macro link must work");
3025   {
3026     // Extract memory strands which may participate in the new object's
3027     // initialization, and source them from the new InitializeNode.
3028     // This will allow us to observe initializations when they occur,
3029     // and link them properly (as a group) to the InitializeNode.
3030     assert(init->in(InitializeNode::Memory) == malloc, "");
3031     MergeMemNode* minit_in = MergeMemNode::make(C, malloc);
3032     init->set_req(InitializeNode::Memory, minit_in);
3033     record_for_igvn(minit_in); // fold it up later, if possible
3034     Node* minit_out = memory(rawidx);
3035     assert(minit_out->is_Proj() && minit_out->in(0) == init, "");
3036     if (oop_type->isa_aryptr()) {
3037       const TypePtr* telemref = oop_type->add_offset(Type::OffsetBot);
3038       int            elemidx  = C->get_alias_index(telemref);
3039       hook_memory_on_init(*this, elemidx, minit_in, minit_out);
3040     } else if (oop_type->isa_instptr()) {
3041       ciInstanceKlass* ik = oop_type->klass()->as_instance_klass();
3042       for (int i = 0, len = ik->nof_nonstatic_fields(); i < len; i++) {
3043         ciField* field = ik->nonstatic_field_at(i);
3044         if (field->offset() >= TrackedInitializationLimit * HeapWordSize)
3045           continue;  // do not bother to track really large numbers of fields
3046         // Find (or create) the alias category for this field:
3047         int fieldidx = C->alias_type(field)->index();
3048         hook_memory_on_init(*this, fieldidx, minit_in, minit_out);
3049       }
3050     }
3051   }
3052 
3053   // Cast raw oop to the real thing...
3054   Node* javaoop = new (C) CheckCastPPNode(control(), rawoop, oop_type);
3055   javaoop = _gvn.transform(javaoop);
3056   C->set_recent_alloc(control(), javaoop);
3057   assert(just_allocated_object(control()) == javaoop, "just allocated");
3058 
3059 #ifdef ASSERT
3060   { // Verify that the AllocateNode::Ideal_allocation recognizers work:
3061     assert(AllocateNode::Ideal_allocation(rawoop, &_gvn) == alloc,
3062            "Ideal_allocation works");
3063     assert(AllocateNode::Ideal_allocation(javaoop, &_gvn) == alloc,
3064            "Ideal_allocation works");
3065     if (alloc->is_AllocateArray()) {
3066       assert(AllocateArrayNode::Ideal_array_allocation(rawoop, &_gvn) == alloc->as_AllocateArray(),
3067              "Ideal_allocation works");
3068       assert(AllocateArrayNode::Ideal_array_allocation(javaoop, &_gvn) == alloc->as_AllocateArray(),
3069              "Ideal_allocation works");
3070     } else {
3071       assert(alloc->in(AllocateNode::ALength)->is_top(), "no length, please");
3072     }
3073   }
3074 #endif //ASSERT
3075 
3076   return javaoop;
3077 }
3078 
3079 //---------------------------new_instance--------------------------------------
3080 // This routine takes a klass_node which may be constant (for a static type)
3081 // or may be non-constant (for reflective code).  It will work equally well
3082 // for either, and the graph will fold nicely if the optimizer later reduces
3083 // the type to a constant.
3084 // The optional arguments are for specialized use by intrinsics:
3085 //  - If 'extra_slow_test' if not null is an extra condition for the slow-path.
3086 //  - If 'return_size_val', report the the total object size to the caller.
3087 Node* GraphKit::new_instance(Node* klass_node,
3088                              Node* extra_slow_test,
3089                              Node* *return_size_val) {
3090   // Compute size in doublewords
3091   // The size is always an integral number of doublewords, represented
3092   // as a positive bytewise size stored in the klass's layout_helper.
3093   // The layout_helper also encodes (in a low bit) the need for a slow path.
3094   jint  layout_con = Klass::_lh_neutral_value;
3095   Node* layout_val = get_layout_helper(klass_node, layout_con);
3096   int   layout_is_con = (layout_val == NULL);
3097 
3098   if (extra_slow_test == NULL)  extra_slow_test = intcon(0);
3099   // Generate the initial go-slow test.  It's either ALWAYS (return a
3100   // Node for 1) or NEVER (return a NULL) or perhaps (in the reflective
3101   // case) a computed value derived from the layout_helper.
3102   Node* initial_slow_test = NULL;
3103   if (layout_is_con) {
3104     assert(!StressReflectiveCode, "stress mode does not use these paths");
3105     bool must_go_slow = Klass::layout_helper_needs_slow_path(layout_con);
3106     initial_slow_test = must_go_slow? intcon(1): extra_slow_test;
3107 
3108   } else {   // reflective case
3109     // This reflective path is used by Unsafe.allocateInstance.
3110     // (It may be stress-tested by specifying StressReflectiveCode.)
3111     // Basically, we want to get into the VM is there's an illegal argument.
3112     Node* bit = intcon(Klass::_lh_instance_slow_path_bit);
3113     initial_slow_test = _gvn.transform( new (C) AndINode(layout_val, bit) );
3114     if (extra_slow_test != intcon(0)) {
3115       initial_slow_test = _gvn.transform( new (C) OrINode(initial_slow_test, extra_slow_test) );
3116     }
3117     // (Macro-expander will further convert this to a Bool, if necessary.)
3118   }
3119 
3120   // Find the size in bytes.  This is easy; it's the layout_helper.
3121   // The size value must be valid even if the slow path is taken.
3122   Node* size = NULL;
3123   if (layout_is_con) {
3124     size = MakeConX(Klass::layout_helper_size_in_bytes(layout_con));
3125   } else {   // reflective case
3126     // This reflective path is used by clone and Unsafe.allocateInstance.
3127     size = ConvI2X(layout_val);
3128 
3129     // Clear the low bits to extract layout_helper_size_in_bytes:
3130     assert((int)Klass::_lh_instance_slow_path_bit < BytesPerLong, "clear bit");
3131     Node* mask = MakeConX(~ (intptr_t)right_n_bits(LogBytesPerLong));
3132     size = _gvn.transform( new (C) AndXNode(size, mask) );
3133   }
3134   if (return_size_val != NULL) {
3135     (*return_size_val) = size;
3136   }
3137 
3138   // This is a precise notnull oop of the klass.
3139   // (Actually, it need not be precise if this is a reflective allocation.)
3140   // It's what we cast the result to.
3141   const TypeKlassPtr* tklass = _gvn.type(klass_node)->isa_klassptr();
3142   if (!tklass)  tklass = TypeKlassPtr::OBJECT;
3143   const TypeOopPtr* oop_type = tklass->as_instance_type();
3144 
3145   // Now generate allocation code
3146 
3147   // The entire memory state is needed for slow path of the allocation
3148   // since GC and deoptimization can happened.
3149   Node *mem = reset_memory();
3150   set_all_memory(mem); // Create new memory state
3151 
3152   AllocateNode* alloc
3153     = new (C) AllocateNode(C, AllocateNode::alloc_type(Type::TOP),
3154                            control(), mem, i_o(),
3155                            size, klass_node,
3156                            initial_slow_test);
3157 
3158   return set_output_for_allocation(alloc, oop_type);
3159 }
3160 
3161 //-------------------------------new_array-------------------------------------
3162 // helper for both newarray and anewarray
3163 // The 'length' parameter is (obviously) the length of the array.
3164 // See comments on new_instance for the meaning of the other arguments.
3165 Node* GraphKit::new_array(Node* klass_node,     // array klass (maybe variable)
3166                           Node* length,         // number of array elements
3167                           int   nargs,          // number of arguments to push back for uncommon trap
3168                           Node* *return_size_val) {
3169   jint  layout_con = Klass::_lh_neutral_value;
3170   Node* layout_val = get_layout_helper(klass_node, layout_con);
3171   int   layout_is_con = (layout_val == NULL);
3172 
3173   if (!layout_is_con && !StressReflectiveCode &&
3174       !too_many_traps(Deoptimization::Reason_class_check)) {
3175     // This is a reflective array creation site.
3176     // Optimistically assume that it is a subtype of Object[],
3177     // so that we can fold up all the address arithmetic.
3178     layout_con = Klass::array_layout_helper(T_OBJECT);
3179     Node* cmp_lh = _gvn.transform( new(C) CmpINode(layout_val, intcon(layout_con)) );
3180     Node* bol_lh = _gvn.transform( new(C) BoolNode(cmp_lh, BoolTest::eq) );
3181     { BuildCutout unless(this, bol_lh, PROB_MAX);
3182       inc_sp(nargs);
3183       uncommon_trap(Deoptimization::Reason_class_check,
3184                     Deoptimization::Action_maybe_recompile);
3185     }
3186     layout_val = NULL;
3187     layout_is_con = true;
3188   }
3189 
3190   // Generate the initial go-slow test.  Make sure we do not overflow
3191   // if length is huge (near 2Gig) or negative!  We do not need
3192   // exact double-words here, just a close approximation of needed
3193   // double-words.  We can't add any offset or rounding bits, lest we
3194   // take a size -1 of bytes and make it positive.  Use an unsigned
3195   // compare, so negative sizes look hugely positive.
3196   int fast_size_limit = FastAllocateSizeLimit;
3197   if (layout_is_con) {
3198     assert(!StressReflectiveCode, "stress mode does not use these paths");
3199     // Increase the size limit if we have exact knowledge of array type.
3200     int log2_esize = Klass::layout_helper_log2_element_size(layout_con);
3201     fast_size_limit <<= (LogBytesPerLong - log2_esize);
3202   }
3203 
3204   Node* initial_slow_cmp  = _gvn.transform( new (C) CmpUNode( length, intcon( fast_size_limit ) ) );
3205   Node* initial_slow_test = _gvn.transform( new (C) BoolNode( initial_slow_cmp, BoolTest::gt ) );
3206   if (initial_slow_test->is_Bool()) {
3207     // Hide it behind a CMoveI, or else PhaseIdealLoop::split_up will get sick.
3208     initial_slow_test = initial_slow_test->as_Bool()->as_int_value(&_gvn);
3209   }
3210 
3211   // --- Size Computation ---
3212   // array_size = round_to_heap(array_header + (length << elem_shift));
3213   // where round_to_heap(x) == round_to(x, MinObjAlignmentInBytes)
3214   // and round_to(x, y) == ((x + y-1) & ~(y-1))
3215   // The rounding mask is strength-reduced, if possible.
3216   int round_mask = MinObjAlignmentInBytes - 1;
3217   Node* header_size = NULL;
3218   int   header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
3219   // (T_BYTE has the weakest alignment and size restrictions...)
3220   if (layout_is_con) {
3221     int       hsize  = Klass::layout_helper_header_size(layout_con);
3222     int       eshift = Klass::layout_helper_log2_element_size(layout_con);
3223     BasicType etype  = Klass::layout_helper_element_type(layout_con);
3224     if ((round_mask & ~right_n_bits(eshift)) == 0)
3225       round_mask = 0;  // strength-reduce it if it goes away completely
3226     assert((hsize & right_n_bits(eshift)) == 0, "hsize is pre-rounded");
3227     assert(header_size_min <= hsize, "generic minimum is smallest");
3228     header_size_min = hsize;
3229     header_size = intcon(hsize + round_mask);
3230   } else {
3231     Node* hss   = intcon(Klass::_lh_header_size_shift);
3232     Node* hsm   = intcon(Klass::_lh_header_size_mask);
3233     Node* hsize = _gvn.transform( new(C) URShiftINode(layout_val, hss) );
3234     hsize       = _gvn.transform( new(C) AndINode(hsize, hsm) );
3235     Node* mask  = intcon(round_mask);
3236     header_size = _gvn.transform( new(C) AddINode(hsize, mask) );
3237   }
3238 
3239   Node* elem_shift = NULL;
3240   if (layout_is_con) {
3241     int eshift = Klass::layout_helper_log2_element_size(layout_con);
3242     if (eshift != 0)
3243       elem_shift = intcon(eshift);
3244   } else {
3245     // There is no need to mask or shift this value.
3246     // The semantics of LShiftINode include an implicit mask to 0x1F.
3247     assert(Klass::_lh_log2_element_size_shift == 0, "use shift in place");
3248     elem_shift = layout_val;
3249   }
3250 
3251   // Transition to native address size for all offset calculations:
3252   Node* lengthx = ConvI2X(length);
3253   Node* headerx = ConvI2X(header_size);
3254 #ifdef _LP64
3255   { const TypeLong* tllen = _gvn.find_long_type(lengthx);
3256     if (tllen != NULL && tllen->_lo < 0) {
3257       // Add a manual constraint to a positive range.  Cf. array_element_address.
3258       jlong size_max = arrayOopDesc::max_array_length(T_BYTE);
3259       if (size_max > tllen->_hi)  size_max = tllen->_hi;
3260       const TypeLong* tlcon = TypeLong::make(CONST64(0), size_max, Type::WidenMin);
3261       lengthx = _gvn.transform( new (C) ConvI2LNode(length, tlcon));
3262     }
3263   }
3264 #endif
3265 
3266   // Combine header size (plus rounding) and body size.  Then round down.
3267   // This computation cannot overflow, because it is used only in two
3268   // places, one where the length is sharply limited, and the other
3269   // after a successful allocation.
3270   Node* abody = lengthx;
3271   if (elem_shift != NULL)
3272     abody     = _gvn.transform( new(C) LShiftXNode(lengthx, elem_shift) );
3273   Node* size  = _gvn.transform( new(C) AddXNode(headerx, abody) );
3274   if (round_mask != 0) {
3275     Node* mask = MakeConX(~round_mask);
3276     size       = _gvn.transform( new(C) AndXNode(size, mask) );
3277   }
3278   // else if round_mask == 0, the size computation is self-rounding
3279 
3280   if (return_size_val != NULL) {
3281     // This is the size
3282     (*return_size_val) = size;
3283   }
3284 
3285   // Now generate allocation code
3286 
3287   // The entire memory state is needed for slow path of the allocation
3288   // since GC and deoptimization can happened.
3289   Node *mem = reset_memory();
3290   set_all_memory(mem); // Create new memory state
3291 
3292   // Create the AllocateArrayNode and its result projections
3293   AllocateArrayNode* alloc
3294     = new (C) AllocateArrayNode(C, AllocateArrayNode::alloc_type(TypeInt::INT),
3295                                 control(), mem, i_o(),
3296                                 size, klass_node,
3297                                 initial_slow_test,
3298                                 length);
3299 
3300   // Cast to correct type.  Note that the klass_node may be constant or not,
3301   // and in the latter case the actual array type will be inexact also.
3302   // (This happens via a non-constant argument to inline_native_newArray.)
3303   // In any case, the value of klass_node provides the desired array type.
3304   const TypeInt* length_type = _gvn.find_int_type(length);
3305   const TypeOopPtr* ary_type = _gvn.type(klass_node)->is_klassptr()->as_instance_type();
3306   if (ary_type->isa_aryptr() && length_type != NULL) {
3307     // Try to get a better type than POS for the size
3308     ary_type = ary_type->is_aryptr()->cast_to_size(length_type);
3309   }
3310 
3311   Node* javaoop = set_output_for_allocation(alloc, ary_type);
3312 
3313   // Cast length on remaining path to be as narrow as possible
3314   if (map()->find_edge(length) >= 0) {
3315     Node* ccast = alloc->make_ideal_length(ary_type, &_gvn);
3316     if (ccast != length) {
3317       _gvn.set_type_bottom(ccast);
3318       record_for_igvn(ccast);
3319       replace_in_map(length, ccast);
3320     }
3321   }
3322 
3323   return javaoop;
3324 }
3325 
3326 // The following "Ideal_foo" functions are placed here because they recognize
3327 // the graph shapes created by the functions immediately above.
3328 
3329 //---------------------------Ideal_allocation----------------------------------
3330 // Given an oop pointer or raw pointer, see if it feeds from an AllocateNode.
3331 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase) {
3332   if (ptr == NULL) {     // reduce dumb test in callers
3333     return NULL;
3334   }
3335   if (ptr->is_CheckCastPP()) { // strip only one raw-to-oop cast
3336     ptr = ptr->in(1);
3337     if (ptr == NULL) return NULL;
3338   }
3339   // Return NULL for allocations with several casts:
3340   //   j.l.reflect.Array.newInstance(jobject, jint)
3341   //   Object.clone()
3342   // to keep more precise type from last cast.
3343   if (ptr->is_Proj()) {
3344     Node* allo = ptr->in(0);
3345     if (allo != NULL && allo->is_Allocate()) {
3346       return allo->as_Allocate();
3347     }
3348   }
3349   // Report failure to match.
3350   return NULL;
3351 }
3352 
3353 // Fancy version which also strips off an offset (and reports it to caller).
3354 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase,
3355                                              intptr_t& offset) {
3356   Node* base = AddPNode::Ideal_base_and_offset(ptr, phase, offset);
3357   if (base == NULL)  return NULL;
3358   return Ideal_allocation(base, phase);
3359 }
3360 
3361 // Trace Initialize <- Proj[Parm] <- Allocate
3362 AllocateNode* InitializeNode::allocation() {
3363   Node* rawoop = in(InitializeNode::RawAddress);
3364   if (rawoop->is_Proj()) {
3365     Node* alloc = rawoop->in(0);
3366     if (alloc->is_Allocate()) {
3367       return alloc->as_Allocate();
3368     }
3369   }
3370   return NULL;
3371 }
3372 
3373 // Trace Allocate -> Proj[Parm] -> Initialize
3374 InitializeNode* AllocateNode::initialization() {
3375   ProjNode* rawoop = proj_out(AllocateNode::RawAddress);
3376   if (rawoop == NULL)  return NULL;
3377   for (DUIterator_Fast imax, i = rawoop->fast_outs(imax); i < imax; i++) {
3378     Node* init = rawoop->fast_out(i);
3379     if (init->is_Initialize()) {
3380       assert(init->as_Initialize()->allocation() == this, "2-way link");
3381       return init->as_Initialize();
3382     }
3383   }
3384   return NULL;
3385 }
3386 
3387 //----------------------------- loop predicates ---------------------------
3388 
3389 //------------------------------add_predicate_impl----------------------------
3390 void GraphKit::add_predicate_impl(Deoptimization::DeoptReason reason, int nargs) {
3391   // Too many traps seen?
3392   if (too_many_traps(reason)) {
3393 #ifdef ASSERT
3394     if (TraceLoopPredicate) {
3395       int tc = C->trap_count(reason);
3396       tty->print("too many traps=%s tcount=%d in ",
3397                     Deoptimization::trap_reason_name(reason), tc);
3398       method()->print(); // which method has too many predicate traps
3399       tty->cr();
3400     }
3401 #endif
3402     // We cannot afford to take more traps here,
3403     // do not generate predicate.
3404     return;
3405   }
3406 
3407   Node *cont    = _gvn.intcon(1);
3408   Node* opq     = _gvn.transform(new (C) Opaque1Node(C, cont));
3409   Node *bol     = _gvn.transform(new (C) Conv2BNode(opq));
3410   IfNode* iff   = create_and_map_if(control(), bol, PROB_MAX, COUNT_UNKNOWN);
3411   Node* iffalse = _gvn.transform(new (C) IfFalseNode(iff));
3412   C->add_predicate_opaq(opq);
3413   {
3414     PreserveJVMState pjvms(this);
3415     set_control(iffalse);
3416     inc_sp(nargs);
3417     uncommon_trap(reason, Deoptimization::Action_maybe_recompile);
3418   }
3419   Node* iftrue = _gvn.transform(new (C) IfTrueNode(iff));
3420   set_control(iftrue);
3421 }
3422 
3423 //------------------------------add_predicate---------------------------------
3424 void GraphKit::add_predicate(int nargs) {
3425   if (UseLoopPredicate) {
3426     add_predicate_impl(Deoptimization::Reason_predicate, nargs);
3427   }
3428   // loop's limit check predicate should be near the loop.
3429   if (LoopLimitCheck) {
3430     add_predicate_impl(Deoptimization::Reason_loop_limit_check, nargs);
3431   }
3432 }
3433 
3434 //----------------------------- store barriers ----------------------------
3435 #define __ ideal.
3436 
3437 void GraphKit::sync_kit(IdealKit& ideal) {
3438   set_all_memory(__ merged_memory());
3439   set_i_o(__ i_o());
3440   set_control(__ ctrl());
3441 }
3442 
3443 void GraphKit::final_sync(IdealKit& ideal) {
3444   // Final sync IdealKit and graphKit.
3445   sync_kit(ideal);
3446 }
3447 
3448 // vanilla/CMS post barrier
3449 // Insert a write-barrier store.  This is to let generational GC work; we have
3450 // to flag all oop-stores before the next GC point.
3451 void GraphKit::write_barrier_post(Node* oop_store,
3452                                   Node* obj,
3453                                   Node* adr,
3454                                   uint  adr_idx,
3455                                   Node* val,
3456                                   bool use_precise) {
3457   // No store check needed if we're storing a NULL or an old object
3458   // (latter case is probably a string constant). The concurrent
3459   // mark sweep garbage collector, however, needs to have all nonNull
3460   // oop updates flagged via card-marks.
3461   if (val != NULL && val->is_Con()) {
3462     // must be either an oop or NULL
3463     const Type* t = val->bottom_type();
3464     if (t == TypePtr::NULL_PTR || t == Type::TOP)
3465       // stores of null never (?) need barriers
3466       return;
3467   }
3468 
3469   if (use_ReduceInitialCardMarks()
3470       && obj == just_allocated_object(control())) {
3471     // We can skip marks on a freshly-allocated object in Eden.
3472     // Keep this code in sync with new_store_pre_barrier() in runtime.cpp.
3473     // That routine informs GC to take appropriate compensating steps,
3474     // upon a slow-path allocation, so as to make this card-mark
3475     // elision safe.
3476     return;
3477   }
3478 
3479   if (!use_precise) {
3480     // All card marks for a (non-array) instance are in one place:
3481     adr = obj;
3482   }
3483   // (Else it's an array (or unknown), and we want more precise card marks.)
3484   assert(adr != NULL, "");
3485 
3486   IdealKit ideal(this, true);
3487 
3488   // Convert the pointer to an int prior to doing math on it
3489   Node* cast = __ CastPX(__ ctrl(), adr);
3490 
3491   // Divide by card size
3492   assert(Universe::heap()->barrier_set()->kind() == BarrierSet::CardTableModRef,
3493          "Only one we handle so far.");
3494   Node* card_offset = __ URShiftX( cast, __ ConI(CardTableModRefBS::card_shift) );
3495 
3496   // Combine card table base and card offset
3497   Node* card_adr = __ AddP(__ top(), byte_map_base_node(), card_offset );
3498 
3499   // Get the alias_index for raw card-mark memory
3500   int adr_type = Compile::AliasIdxRaw;
3501   Node*   zero = __ ConI(0); // Dirty card value
3502   BasicType bt = T_BYTE;
3503 
3504   if (UseCondCardMark) {
3505     // The classic GC reference write barrier is typically implemented
3506     // as a store into the global card mark table.  Unfortunately
3507     // unconditional stores can result in false sharing and excessive
3508     // coherence traffic as well as false transactional aborts.
3509     // UseCondCardMark enables MP "polite" conditional card mark
3510     // stores.  In theory we could relax the load from ctrl() to
3511     // no_ctrl, but that doesn't buy much latitude.
3512     Node* card_val = __ load( __ ctrl(), card_adr, TypeInt::BYTE, bt, adr_type);
3513     __ if_then(card_val, BoolTest::ne, zero);
3514   }
3515 
3516   // Smash zero into card
3517   if( !UseConcMarkSweepGC ) {
3518     __ store(__ ctrl(), card_adr, zero, bt, adr_type);
3519   } else {
3520     // Specialized path for CM store barrier
3521     __ storeCM(__ ctrl(), card_adr, zero, oop_store, adr_idx, bt, adr_type);
3522   }
3523 
3524   if (UseCondCardMark) {
3525     __ end_if();
3526   }
3527 
3528   // Final sync IdealKit and GraphKit.
3529   final_sync(ideal);
3530 }
3531 
3532 // G1 pre/post barriers
3533 void GraphKit::g1_write_barrier_pre(bool do_load,
3534                                     Node* obj,
3535                                     Node* adr,
3536                                     uint alias_idx,
3537                                     Node* val,
3538                                     const TypeOopPtr* val_type,
3539                                     Node* pre_val,
3540                                     BasicType bt) {
3541 
3542   // Some sanity checks
3543   // Note: val is unused in this routine.
3544 
3545   if (do_load) {
3546     // We need to generate the load of the previous value
3547     assert(obj != NULL, "must have a base");
3548     assert(adr != NULL, "where are loading from?");
3549     assert(pre_val == NULL, "loaded already?");
3550     assert(val_type != NULL, "need a type");
3551   } else {
3552     // In this case both val_type and alias_idx are unused.
3553     assert(pre_val != NULL, "must be loaded already");


3554     assert(pre_val->bottom_type()->basic_type() == T_OBJECT, "or we shouldn't be here");
3555   }
3556   assert(bt == T_OBJECT, "or we shouldn't be here");
3557 
3558   IdealKit ideal(this, true);
3559 
3560   Node* tls = __ thread(); // ThreadLocalStorage
3561 
3562   Node* no_ctrl = NULL;
3563   Node* no_base = __ top();
3564   Node* zero  = __ ConI(0);
3565   Node* zeroX = __ ConX(0);
3566 
3567   float likely  = PROB_LIKELY(0.999);
3568   float unlikely  = PROB_UNLIKELY(0.999);
3569 
3570   BasicType active_type = in_bytes(PtrQueue::byte_width_of_active()) == 4 ? T_INT : T_BYTE;
3571   assert(in_bytes(PtrQueue::byte_width_of_active()) == 4 || in_bytes(PtrQueue::byte_width_of_active()) == 1, "flag width");
3572 
3573   // Offsets into the thread
3574   const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() +  // 648
3575                                           PtrQueue::byte_offset_of_active());
3576   const int index_offset   = in_bytes(JavaThread::satb_mark_queue_offset() +  // 656
3577                                           PtrQueue::byte_offset_of_index());
3578   const int buffer_offset  = in_bytes(JavaThread::satb_mark_queue_offset() +  // 652
3579                                           PtrQueue::byte_offset_of_buf());
3580 
3581   // Now the actual pointers into the thread
3582   Node* marking_adr = __ AddP(no_base, tls, __ ConX(marking_offset));
3583   Node* buffer_adr  = __ AddP(no_base, tls, __ ConX(buffer_offset));
3584   Node* index_adr   = __ AddP(no_base, tls, __ ConX(index_offset));
3585 
3586   // Now some of the values
3587   Node* marking = __ load(__ ctrl(), marking_adr, TypeInt::INT, active_type, Compile::AliasIdxRaw);
3588 
3589   // if (!marking)
3590   __ if_then(marking, BoolTest::ne, zero); {
3591     BasicType index_bt = TypeX_X->basic_type();
3592     assert(sizeof(size_t) == type2aelembytes(index_bt), "Loading G1 PtrQueue::_index with wrong size.");
3593     Node* index   = __ load(__ ctrl(), index_adr, TypeX_X, index_bt, Compile::AliasIdxRaw);
3594 
3595     if (do_load) {
3596       // load original value
3597       // alias_idx correct??
3598       pre_val = __ load(no_ctrl, adr, val_type, bt, alias_idx);
3599     }
3600 
3601     // if (pre_val != NULL)
3602     __ if_then(pre_val, BoolTest::ne, null()); {
3603       Node* buffer  = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
3604 
3605       // is the queue for this thread full?
3606       __ if_then(index, BoolTest::ne, zeroX, likely); {
3607 
3608         // decrement the index
3609         Node* next_index = _gvn.transform(new (C) SubXNode(index, __ ConX(sizeof(intptr_t))));
3610 
3611         // Now get the buffer location we will log the previous value into and store it
3612         Node *log_addr = __ AddP(no_base, buffer, next_index);
3613         __ store(__ ctrl(), log_addr, pre_val, T_OBJECT, Compile::AliasIdxRaw);
3614         // update the index
3615         __ store(__ ctrl(), index_adr, next_index, index_bt, Compile::AliasIdxRaw);
3616 
3617       } __ else_(); {
3618 
3619         // logging buffer is full, call the runtime
3620         const TypeFunc *tf = OptoRuntime::g1_wb_pre_Type();
3621         __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_pre), "g1_wb_pre", pre_val, tls);
3622       } __ end_if();  // (!index)
3623     } __ end_if();  // (pre_val != NULL)
3624   } __ end_if();  // (!marking)
3625 
3626   // Final sync IdealKit and GraphKit.
3627   final_sync(ideal);
3628 }
3629 
3630 //
3631 // Update the card table and add card address to the queue
3632 //
3633 void GraphKit::g1_mark_card(IdealKit& ideal,
3634                             Node* card_adr,
3635                             Node* oop_store,
3636                             uint oop_alias_idx,
3637                             Node* index,
3638                             Node* index_adr,
3639                             Node* buffer,
3640                             const TypeFunc* tf) {
3641 
3642   Node* zero  = __ ConI(0);
3643   Node* zeroX = __ ConX(0);
3644   Node* no_base = __ top();
3645   BasicType card_bt = T_BYTE;
3646   // Smash zero into card. MUST BE ORDERED WRT TO STORE
3647   __ storeCM(__ ctrl(), card_adr, zero, oop_store, oop_alias_idx, card_bt, Compile::AliasIdxRaw);
3648 
3649   //  Now do the queue work
3650   __ if_then(index, BoolTest::ne, zeroX); {
3651 
3652     Node* next_index = _gvn.transform(new (C) SubXNode(index, __ ConX(sizeof(intptr_t))));
3653     Node* log_addr = __ AddP(no_base, buffer, next_index);
3654 
3655     __ store(__ ctrl(), log_addr, card_adr, T_ADDRESS, Compile::AliasIdxRaw);
3656     __ store(__ ctrl(), index_adr, next_index, TypeX_X->basic_type(), Compile::AliasIdxRaw);
3657 
3658   } __ else_(); {
3659     __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_post), "g1_wb_post", card_adr, __ thread());
3660   } __ end_if();
3661 
3662 }
3663 
3664 void GraphKit::g1_write_barrier_post(Node* oop_store,
3665                                      Node* obj,
3666                                      Node* adr,
3667                                      uint alias_idx,
3668                                      Node* val,
3669                                      BasicType bt,
3670                                      bool use_precise) {
3671   // If we are writing a NULL then we need no post barrier
3672 
3673   if (val != NULL && val->is_Con() && val->bottom_type() == TypePtr::NULL_PTR) {
3674     // Must be NULL
3675     const Type* t = val->bottom_type();
3676     assert(t == Type::TOP || t == TypePtr::NULL_PTR, "must be NULL");
3677     // No post barrier if writing NULLx
3678     return;
3679   }
3680 
3681   if (!use_precise) {
3682     // All card marks for a (non-array) instance are in one place:
3683     adr = obj;
3684   }
3685   // (Else it's an array (or unknown), and we want more precise card marks.)
3686   assert(adr != NULL, "");
3687 
3688   IdealKit ideal(this, true);
3689 
3690   Node* tls = __ thread(); // ThreadLocalStorage
3691 
3692   Node* no_base = __ top();
3693   float likely  = PROB_LIKELY(0.999);
3694   float unlikely  = PROB_UNLIKELY(0.999);
3695   Node* zero = __ ConI(0);
3696   Node* zeroX = __ ConX(0);
3697 
3698   // Get the alias_index for raw card-mark memory
3699   const TypePtr* card_type = TypeRawPtr::BOTTOM;
3700 
3701   const TypeFunc *tf = OptoRuntime::g1_wb_post_Type();
3702 
3703   // Offsets into the thread
3704   const int index_offset  = in_bytes(JavaThread::dirty_card_queue_offset() +
3705                                      PtrQueue::byte_offset_of_index());
3706   const int buffer_offset = in_bytes(JavaThread::dirty_card_queue_offset() +
3707                                      PtrQueue::byte_offset_of_buf());
3708 
3709   // Pointers into the thread
3710 
3711   Node* buffer_adr = __ AddP(no_base, tls, __ ConX(buffer_offset));
3712   Node* index_adr =  __ AddP(no_base, tls, __ ConX(index_offset));
3713 
3714   // Now some values
3715   // Use ctrl to avoid hoisting these values past a safepoint, which could
3716   // potentially reset these fields in the JavaThread.
3717   Node* index  = __ load(__ ctrl(), index_adr, TypeX_X, TypeX_X->basic_type(), Compile::AliasIdxRaw);
3718   Node* buffer = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
3719 
3720   // Convert the store obj pointer to an int prior to doing math on it
3721   // Must use ctrl to prevent "integerized oop" existing across safepoint
3722   Node* cast =  __ CastPX(__ ctrl(), adr);
3723 
3724   // Divide pointer by card size
3725   Node* card_offset = __ URShiftX( cast, __ ConI(CardTableModRefBS::card_shift) );
3726 
3727   // Combine card table base and card offset
3728   Node* card_adr = __ AddP(no_base, byte_map_base_node(), card_offset );
3729 
3730   // If we know the value being stored does it cross regions?
3731 
3732   if (val != NULL) {
3733     // Does the store cause us to cross regions?
3734 
3735     // Should be able to do an unsigned compare of region_size instead of
3736     // and extra shift. Do we have an unsigned compare??
3737     // Node* region_size = __ ConI(1 << HeapRegion::LogOfHRGrainBytes);
3738     Node* xor_res =  __ URShiftX ( __ XorX( cast,  __ CastPX(__ ctrl(), val)), __ ConI(HeapRegion::LogOfHRGrainBytes));
3739 
3740     // if (xor_res == 0) same region so skip
3741     __ if_then(xor_res, BoolTest::ne, zeroX); {
3742 
3743       // No barrier if we are storing a NULL
3744       __ if_then(val, BoolTest::ne, null(), unlikely); {
3745 
3746         // Ok must mark the card if not already dirty
3747 
3748         // load the original value of the card
3749         Node* card_val = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
3750 
3751         __ if_then(card_val, BoolTest::ne, zero); {
3752           g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
3753         } __ end_if();
3754       } __ end_if();
3755     } __ end_if();
3756   } else {
3757     // Object.clone() instrinsic uses this path.
3758     g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
3759   }
3760 
3761   // Final sync IdealKit and GraphKit.
3762   final_sync(ideal);
3763 }
3764 #undef __
3765 
3766 
3767 
3768 Node* GraphKit::load_String_offset(Node* ctrl, Node* str) {
3769   if (java_lang_String::has_offset_field()) {
3770     int offset_offset = java_lang_String::offset_offset_in_bytes();
3771     const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
3772                                                        false, NULL, 0);
3773     const TypePtr* offset_field_type = string_type->add_offset(offset_offset);
3774     int offset_field_idx = C->get_alias_index(offset_field_type);
3775     return make_load(ctrl,
3776                      basic_plus_adr(str, str, offset_offset),
3777                      TypeInt::INT, T_INT, offset_field_idx);
3778   } else {
3779     return intcon(0);
3780   }
3781 }
3782 
3783 Node* GraphKit::load_String_length(Node* ctrl, Node* str) {
3784   if (java_lang_String::has_count_field()) {
3785     int count_offset = java_lang_String::count_offset_in_bytes();
3786     const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
3787                                                        false, NULL, 0);
3788     const TypePtr* count_field_type = string_type->add_offset(count_offset);
3789     int count_field_idx = C->get_alias_index(count_field_type);
3790     return make_load(ctrl,
3791                      basic_plus_adr(str, str, count_offset),
3792                      TypeInt::INT, T_INT, count_field_idx);
3793   } else {
3794     return load_array_length(load_String_value(ctrl, str));
3795   }
3796 }
3797 
3798 Node* GraphKit::load_String_value(Node* ctrl, Node* str) {
3799   int value_offset = java_lang_String::value_offset_in_bytes();
3800   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
3801                                                      false, NULL, 0);
3802   const TypePtr* value_field_type = string_type->add_offset(value_offset);
3803   const TypeAryPtr*  value_type = TypeAryPtr::make(TypePtr::NotNull,
3804                                                    TypeAry::make(TypeInt::CHAR,TypeInt::POS),
3805                                                    ciTypeArrayKlass::make(T_CHAR), true, 0);
3806   int value_field_idx = C->get_alias_index(value_field_type);
3807   return make_load(ctrl, basic_plus_adr(str, str, value_offset),
3808                    value_type, T_OBJECT, value_field_idx);
3809 }
3810 
3811 void GraphKit::store_String_offset(Node* ctrl, Node* str, Node* value) {
3812   int offset_offset = java_lang_String::offset_offset_in_bytes();
3813   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
3814                                                      false, NULL, 0);
3815   const TypePtr* offset_field_type = string_type->add_offset(offset_offset);
3816   int offset_field_idx = C->get_alias_index(offset_field_type);
3817   store_to_memory(ctrl, basic_plus_adr(str, offset_offset),
3818                   value, T_INT, offset_field_idx);
3819 }
3820 
3821 void GraphKit::store_String_value(Node* ctrl, Node* str, Node* value) {
3822   int value_offset = java_lang_String::value_offset_in_bytes();
3823   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
3824                                                      false, NULL, 0);
3825   const TypePtr* value_field_type = string_type->add_offset(value_offset);
3826   const TypeAryPtr*  value_type = TypeAryPtr::make(TypePtr::NotNull,
3827                                                    TypeAry::make(TypeInt::CHAR,TypeInt::POS),
3828                                                    ciTypeArrayKlass::make(T_CHAR), true, 0);
3829   int value_field_idx = C->get_alias_index(value_field_type);
3830   store_to_memory(ctrl, basic_plus_adr(str, value_offset),
3831                   value, T_OBJECT, value_field_idx);
3832 }
3833 
3834 void GraphKit::store_String_length(Node* ctrl, Node* str, Node* value) {
3835   int count_offset = java_lang_String::count_offset_in_bytes();
3836   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
3837                                                      false, NULL, 0);
3838   const TypePtr* count_field_type = string_type->add_offset(count_offset);
3839   int count_field_idx = C->get_alias_index(count_field_type);
3840   store_to_memory(ctrl, basic_plus_adr(str, count_offset),
3841                   value, T_INT, count_field_idx);
3842 }
--- EOF ---