1 /*
   2  * Copyright 2001-2009 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  20  * CA 95054 USA or visit www.sun.com if you need additional information or
  21  * have any questions.
  22  *
  23  */
  24 
  25 #include "incls/_precompiled.incl"
  26 #include "incls/_graphKit.cpp.incl"
  27 
  28 //----------------------------GraphKit-----------------------------------------
  29 // Main utility constructor.
  30 GraphKit::GraphKit(JVMState* jvms)
  31   : Phase(Phase::Parser),
  32     _env(C->env()),
  33     _gvn(*C->initial_gvn())
  34 {
  35   _exceptions = jvms->map()->next_exception();
  36   if (_exceptions != NULL)  jvms->map()->set_next_exception(NULL);
  37   set_jvms(jvms);
  38 }
  39 
  40 // Private constructor for parser.
  41 GraphKit::GraphKit()
  42   : Phase(Phase::Parser),
  43     _env(C->env()),
  44     _gvn(*C->initial_gvn())
  45 {
  46   _exceptions = NULL;
  47   set_map(NULL);
  48   debug_only(_sp = -99);
  49   debug_only(set_bci(-99));
  50 }
  51 
  52 
  53 
  54 //---------------------------clean_stack---------------------------------------
  55 // Clear away rubbish from the stack area of the JVM state.
  56 // This destroys any arguments that may be waiting on the stack.
  57 void GraphKit::clean_stack(int from_sp) {
  58   SafePointNode* map      = this->map();
  59   JVMState*      jvms     = this->jvms();
  60   int            stk_size = jvms->stk_size();
  61   int            stkoff   = jvms->stkoff();
  62   Node*          top      = this->top();
  63   for (int i = from_sp; i < stk_size; i++) {
  64     if (map->in(stkoff + i) != top) {
  65       map->set_req(stkoff + i, top);
  66     }
  67   }
  68 }
  69 
  70 
  71 //--------------------------------sync_jvms-----------------------------------
  72 // Make sure our current jvms agrees with our parse state.
  73 JVMState* GraphKit::sync_jvms() const {
  74   JVMState* jvms = this->jvms();
  75   jvms->set_bci(bci());       // Record the new bci in the JVMState
  76   jvms->set_sp(sp());         // Record the new sp in the JVMState
  77   assert(jvms_in_sync(), "jvms is now in sync");
  78   return jvms;
  79 }
  80 
  81 #ifdef ASSERT
  82 bool GraphKit::jvms_in_sync() const {
  83   Parse* parse = is_Parse();
  84   if (parse == NULL) {
  85     if (bci() !=      jvms()->bci())          return false;
  86     if (sp()  != (int)jvms()->sp())           return false;
  87     return true;
  88   }
  89   if (jvms()->method() != parse->method())    return false;
  90   if (jvms()->bci()    != parse->bci())       return false;
  91   int jvms_sp = jvms()->sp();
  92   if (jvms_sp          != parse->sp())        return false;
  93   int jvms_depth = jvms()->depth();
  94   if (jvms_depth       != parse->depth())     return false;
  95   return true;
  96 }
  97 
  98 // Local helper checks for special internal merge points
  99 // used to accumulate and merge exception states.
 100 // They are marked by the region's in(0) edge being the map itself.
 101 // Such merge points must never "escape" into the parser at large,
 102 // until they have been handed to gvn.transform.
 103 static bool is_hidden_merge(Node* reg) {
 104   if (reg == NULL)  return false;
 105   if (reg->is_Phi()) {
 106     reg = reg->in(0);
 107     if (reg == NULL)  return false;
 108   }
 109   return reg->is_Region() && reg->in(0) != NULL && reg->in(0)->is_Root();
 110 }
 111 
 112 void GraphKit::verify_map() const {
 113   if (map() == NULL)  return;  // null map is OK
 114   assert(map()->req() <= jvms()->endoff(), "no extra garbage on map");
 115   assert(!map()->has_exceptions(),    "call add_exception_states_from 1st");
 116   assert(!is_hidden_merge(control()), "call use_exception_state, not set_map");
 117 }
 118 
 119 void GraphKit::verify_exception_state(SafePointNode* ex_map) {
 120   assert(ex_map->next_exception() == NULL, "not already part of a chain");
 121   assert(has_saved_ex_oop(ex_map), "every exception state has an ex_oop");
 122 }
 123 #endif
 124 
 125 //---------------------------stop_and_kill_map---------------------------------
 126 // Set _map to NULL, signalling a stop to further bytecode execution.
 127 // First smash the current map's control to a constant, to mark it dead.
 128 void GraphKit::stop_and_kill_map() {
 129   SafePointNode* dead_map = stop();
 130   if (dead_map != NULL) {
 131     dead_map->disconnect_inputs(NULL); // Mark the map as killed.
 132     assert(dead_map->is_killed(), "must be so marked");
 133   }
 134 }
 135 
 136 
 137 //--------------------------------stopped--------------------------------------
 138 // Tell if _map is NULL, or control is top.
 139 bool GraphKit::stopped() {
 140   if (map() == NULL)           return true;
 141   else if (control() == top()) return true;
 142   else                         return false;
 143 }
 144 
 145 
 146 //-----------------------------has_ex_handler----------------------------------
 147 // Tell if this method or any caller method has exception handlers.
 148 bool GraphKit::has_ex_handler() {
 149   for (JVMState* jvmsp = jvms(); jvmsp != NULL; jvmsp = jvmsp->caller()) {
 150     if (jvmsp->has_method() && jvmsp->method()->has_exception_handlers()) {
 151       return true;
 152     }
 153   }
 154   return false;
 155 }
 156 
 157 //------------------------------save_ex_oop------------------------------------
 158 // Save an exception without blowing stack contents or other JVM state.
 159 void GraphKit::set_saved_ex_oop(SafePointNode* ex_map, Node* ex_oop) {
 160   assert(!has_saved_ex_oop(ex_map), "clear ex-oop before setting again");
 161   ex_map->add_req(ex_oop);
 162   debug_only(verify_exception_state(ex_map));
 163 }
 164 
 165 inline static Node* common_saved_ex_oop(SafePointNode* ex_map, bool clear_it) {
 166   assert(GraphKit::has_saved_ex_oop(ex_map), "ex_oop must be there");
 167   Node* ex_oop = ex_map->in(ex_map->req()-1);
 168   if (clear_it)  ex_map->del_req(ex_map->req()-1);
 169   return ex_oop;
 170 }
 171 
 172 //-----------------------------saved_ex_oop------------------------------------
 173 // Recover a saved exception from its map.
 174 Node* GraphKit::saved_ex_oop(SafePointNode* ex_map) {
 175   return common_saved_ex_oop(ex_map, false);
 176 }
 177 
 178 //--------------------------clear_saved_ex_oop---------------------------------
 179 // Erase a previously saved exception from its map.
 180 Node* GraphKit::clear_saved_ex_oop(SafePointNode* ex_map) {
 181   return common_saved_ex_oop(ex_map, true);
 182 }
 183 
 184 #ifdef ASSERT
 185 //---------------------------has_saved_ex_oop----------------------------------
 186 // Erase a previously saved exception from its map.
 187 bool GraphKit::has_saved_ex_oop(SafePointNode* ex_map) {
 188   return ex_map->req() == ex_map->jvms()->endoff()+1;
 189 }
 190 #endif
 191 
 192 //-------------------------make_exception_state--------------------------------
 193 // Turn the current JVM state into an exception state, appending the ex_oop.
 194 SafePointNode* GraphKit::make_exception_state(Node* ex_oop) {
 195   sync_jvms();
 196   SafePointNode* ex_map = stop();  // do not manipulate this map any more
 197   set_saved_ex_oop(ex_map, ex_oop);
 198   return ex_map;
 199 }
 200 
 201 
 202 //--------------------------add_exception_state--------------------------------
 203 // Add an exception to my list of exceptions.
 204 void GraphKit::add_exception_state(SafePointNode* ex_map) {
 205   if (ex_map == NULL || ex_map->control() == top()) {
 206     return;
 207   }
 208 #ifdef ASSERT
 209   verify_exception_state(ex_map);
 210   if (has_exceptions()) {
 211     assert(ex_map->jvms()->same_calls_as(_exceptions->jvms()), "all collected exceptions must come from the same place");
 212   }
 213 #endif
 214 
 215   // If there is already an exception of exactly this type, merge with it.
 216   // In particular, null-checks and other low-level exceptions common up here.
 217   Node*       ex_oop  = saved_ex_oop(ex_map);
 218   const Type* ex_type = _gvn.type(ex_oop);
 219   if (ex_oop == top()) {
 220     // No action needed.
 221     return;
 222   }
 223   assert(ex_type->isa_instptr(), "exception must be an instance");
 224   for (SafePointNode* e2 = _exceptions; e2 != NULL; e2 = e2->next_exception()) {
 225     const Type* ex_type2 = _gvn.type(saved_ex_oop(e2));
 226     // We check sp also because call bytecodes can generate exceptions
 227     // both before and after arguments are popped!
 228     if (ex_type2 == ex_type
 229         && e2->_jvms->sp() == ex_map->_jvms->sp()) {
 230       combine_exception_states(ex_map, e2);
 231       return;
 232     }
 233   }
 234 
 235   // No pre-existing exception of the same type.  Chain it on the list.
 236   push_exception_state(ex_map);
 237 }
 238 
 239 //-----------------------add_exception_states_from-----------------------------
 240 void GraphKit::add_exception_states_from(JVMState* jvms) {
 241   SafePointNode* ex_map = jvms->map()->next_exception();
 242   if (ex_map != NULL) {
 243     jvms->map()->set_next_exception(NULL);
 244     for (SafePointNode* next_map; ex_map != NULL; ex_map = next_map) {
 245       next_map = ex_map->next_exception();
 246       ex_map->set_next_exception(NULL);
 247       add_exception_state(ex_map);
 248     }
 249   }
 250 }
 251 
 252 //-----------------------transfer_exceptions_into_jvms-------------------------
 253 JVMState* GraphKit::transfer_exceptions_into_jvms() {
 254   if (map() == NULL) {
 255     // We need a JVMS to carry the exceptions, but the map has gone away.
 256     // Create a scratch JVMS, cloned from any of the exception states...
 257     if (has_exceptions()) {
 258       _map = _exceptions;
 259       _map = clone_map();
 260       _map->set_next_exception(NULL);
 261       clear_saved_ex_oop(_map);
 262       debug_only(verify_map());
 263     } else {
 264       // ...or created from scratch
 265       JVMState* jvms = new (C) JVMState(_method, NULL);
 266       jvms->set_bci(_bci);
 267       jvms->set_sp(_sp);
 268       jvms->set_map(new (C, TypeFunc::Parms) SafePointNode(TypeFunc::Parms, jvms));
 269       set_jvms(jvms);
 270       for (uint i = 0; i < map()->req(); i++)  map()->init_req(i, top());
 271       set_all_memory(top());
 272       while (map()->req() < jvms->endoff())  map()->add_req(top());
 273     }
 274     // (This is a kludge, in case you didn't notice.)
 275     set_control(top());
 276   }
 277   JVMState* jvms = sync_jvms();
 278   assert(!jvms->map()->has_exceptions(), "no exceptions on this map yet");
 279   jvms->map()->set_next_exception(_exceptions);
 280   _exceptions = NULL;   // done with this set of exceptions
 281   return jvms;
 282 }
 283 
 284 static inline void add_n_reqs(Node* dstphi, Node* srcphi) {
 285   assert(is_hidden_merge(dstphi), "must be a special merge node");
 286   assert(is_hidden_merge(srcphi), "must be a special merge node");
 287   uint limit = srcphi->req();
 288   for (uint i = PhiNode::Input; i < limit; i++) {
 289     dstphi->add_req(srcphi->in(i));
 290   }
 291 }
 292 static inline void add_one_req(Node* dstphi, Node* src) {
 293   assert(is_hidden_merge(dstphi), "must be a special merge node");
 294   assert(!is_hidden_merge(src), "must not be a special merge node");
 295   dstphi->add_req(src);
 296 }
 297 
 298 //-----------------------combine_exception_states------------------------------
 299 // This helper function combines exception states by building phis on a
 300 // specially marked state-merging region.  These regions and phis are
 301 // untransformed, and can build up gradually.  The region is marked by
 302 // having a control input of its exception map, rather than NULL.  Such
 303 // regions do not appear except in this function, and in use_exception_state.
 304 void GraphKit::combine_exception_states(SafePointNode* ex_map, SafePointNode* phi_map) {
 305   if (failing())  return;  // dying anyway...
 306   JVMState* ex_jvms = ex_map->_jvms;
 307   assert(ex_jvms->same_calls_as(phi_map->_jvms), "consistent call chains");
 308   assert(ex_jvms->stkoff() == phi_map->_jvms->stkoff(), "matching locals");
 309   assert(ex_jvms->sp() == phi_map->_jvms->sp(), "matching stack sizes");
 310   assert(ex_jvms->monoff() == phi_map->_jvms->monoff(), "matching JVMS");
 311   assert(ex_map->req() == phi_map->req(), "matching maps");
 312   uint tos = ex_jvms->stkoff() + ex_jvms->sp();
 313   Node*         hidden_merge_mark = root();
 314   Node*         region  = phi_map->control();
 315   MergeMemNode* phi_mem = phi_map->merged_memory();
 316   MergeMemNode* ex_mem  = ex_map->merged_memory();
 317   if (region->in(0) != hidden_merge_mark) {
 318     // The control input is not (yet) a specially-marked region in phi_map.
 319     // Make it so, and build some phis.
 320     region = new (C, 2) RegionNode(2);
 321     _gvn.set_type(region, Type::CONTROL);
 322     region->set_req(0, hidden_merge_mark);  // marks an internal ex-state
 323     region->init_req(1, phi_map->control());
 324     phi_map->set_control(region);
 325     Node* io_phi = PhiNode::make(region, phi_map->i_o(), Type::ABIO);
 326     record_for_igvn(io_phi);
 327     _gvn.set_type(io_phi, Type::ABIO);
 328     phi_map->set_i_o(io_phi);
 329     for (MergeMemStream mms(phi_mem); mms.next_non_empty(); ) {
 330       Node* m = mms.memory();
 331       Node* m_phi = PhiNode::make(region, m, Type::MEMORY, mms.adr_type(C));
 332       record_for_igvn(m_phi);
 333       _gvn.set_type(m_phi, Type::MEMORY);
 334       mms.set_memory(m_phi);
 335     }
 336   }
 337 
 338   // Either or both of phi_map and ex_map might already be converted into phis.
 339   Node* ex_control = ex_map->control();
 340   // if there is special marking on ex_map also, we add multiple edges from src
 341   bool add_multiple = (ex_control->in(0) == hidden_merge_mark);
 342   // how wide was the destination phi_map, originally?
 343   uint orig_width = region->req();
 344 
 345   if (add_multiple) {
 346     add_n_reqs(region, ex_control);
 347     add_n_reqs(phi_map->i_o(), ex_map->i_o());
 348   } else {
 349     // ex_map has no merges, so we just add single edges everywhere
 350     add_one_req(region, ex_control);
 351     add_one_req(phi_map->i_o(), ex_map->i_o());
 352   }
 353   for (MergeMemStream mms(phi_mem, ex_mem); mms.next_non_empty2(); ) {
 354     if (mms.is_empty()) {
 355       // get a copy of the base memory, and patch some inputs into it
 356       const TypePtr* adr_type = mms.adr_type(C);
 357       Node* phi = mms.force_memory()->as_Phi()->slice_memory(adr_type);
 358       assert(phi->as_Phi()->region() == mms.base_memory()->in(0), "");
 359       mms.set_memory(phi);
 360       // Prepare to append interesting stuff onto the newly sliced phi:
 361       while (phi->req() > orig_width)  phi->del_req(phi->req()-1);
 362     }
 363     // Append stuff from ex_map:
 364     if (add_multiple) {
 365       add_n_reqs(mms.memory(), mms.memory2());
 366     } else {
 367       add_one_req(mms.memory(), mms.memory2());
 368     }
 369   }
 370   uint limit = ex_map->req();
 371   for (uint i = TypeFunc::Parms; i < limit; i++) {
 372     // Skip everything in the JVMS after tos.  (The ex_oop follows.)
 373     if (i == tos)  i = ex_jvms->monoff();
 374     Node* src = ex_map->in(i);
 375     Node* dst = phi_map->in(i);
 376     if (src != dst) {
 377       PhiNode* phi;
 378       if (dst->in(0) != region) {
 379         dst = phi = PhiNode::make(region, dst, _gvn.type(dst));
 380         record_for_igvn(phi);
 381         _gvn.set_type(phi, phi->type());
 382         phi_map->set_req(i, dst);
 383         // Prepare to append interesting stuff onto the new phi:
 384         while (dst->req() > orig_width)  dst->del_req(dst->req()-1);
 385       } else {
 386         assert(dst->is_Phi(), "nobody else uses a hidden region");
 387         phi = (PhiNode*)dst;
 388       }
 389       if (add_multiple && src->in(0) == ex_control) {
 390         // Both are phis.
 391         add_n_reqs(dst, src);
 392       } else {
 393         while (dst->req() < region->req())  add_one_req(dst, src);
 394       }
 395       const Type* srctype = _gvn.type(src);
 396       if (phi->type() != srctype) {
 397         const Type* dsttype = phi->type()->meet(srctype);
 398         if (phi->type() != dsttype) {
 399           phi->set_type(dsttype);
 400           _gvn.set_type(phi, dsttype);
 401         }
 402       }
 403     }
 404   }
 405 }
 406 
 407 //--------------------------use_exception_state--------------------------------
 408 Node* GraphKit::use_exception_state(SafePointNode* phi_map) {
 409   if (failing()) { stop(); return top(); }
 410   Node* region = phi_map->control();
 411   Node* hidden_merge_mark = root();
 412   assert(phi_map->jvms()->map() == phi_map, "sanity: 1-1 relation");
 413   Node* ex_oop = clear_saved_ex_oop(phi_map);
 414   if (region->in(0) == hidden_merge_mark) {
 415     // Special marking for internal ex-states.  Process the phis now.
 416     region->set_req(0, region);  // now it's an ordinary region
 417     set_jvms(phi_map->jvms());   // ...so now we can use it as a map
 418     // Note: Setting the jvms also sets the bci and sp.
 419     set_control(_gvn.transform(region));
 420     uint tos = jvms()->stkoff() + sp();
 421     for (uint i = 1; i < tos; i++) {
 422       Node* x = phi_map->in(i);
 423       if (x->in(0) == region) {
 424         assert(x->is_Phi(), "expected a special phi");
 425         phi_map->set_req(i, _gvn.transform(x));
 426       }
 427     }
 428     for (MergeMemStream mms(merged_memory()); mms.next_non_empty(); ) {
 429       Node* x = mms.memory();
 430       if (x->in(0) == region) {
 431         assert(x->is_Phi(), "nobody else uses a hidden region");
 432         mms.set_memory(_gvn.transform(x));
 433       }
 434     }
 435     if (ex_oop->in(0) == region) {
 436       assert(ex_oop->is_Phi(), "expected a special phi");
 437       ex_oop = _gvn.transform(ex_oop);
 438     }
 439   } else {
 440     set_jvms(phi_map->jvms());
 441   }
 442 
 443   assert(!is_hidden_merge(phi_map->control()), "hidden ex. states cleared");
 444   assert(!is_hidden_merge(phi_map->i_o()), "hidden ex. states cleared");
 445   return ex_oop;
 446 }
 447 
 448 //---------------------------------java_bc-------------------------------------
 449 Bytecodes::Code GraphKit::java_bc() const {
 450   ciMethod* method = this->method();
 451   int       bci    = this->bci();
 452   if (method != NULL && bci != InvocationEntryBci)
 453     return method->java_code_at_bci(bci);
 454   else
 455     return Bytecodes::_illegal;
 456 }
 457 
 458 //------------------------------builtin_throw----------------------------------
 459 void GraphKit::builtin_throw(Deoptimization::DeoptReason reason, Node* arg) {
 460   bool must_throw = true;
 461 
 462   if (env()->jvmti_can_post_exceptions()) {
 463     // Do not try anything fancy if we're notifying the VM on every throw.
 464     // Cf. case Bytecodes::_athrow in parse2.cpp.
 465     uncommon_trap(reason, Deoptimization::Action_none,
 466                   (ciKlass*)NULL, (char*)NULL, must_throw);
 467     return;
 468   }
 469 
 470   // If this particular condition has not yet happened at this
 471   // bytecode, then use the uncommon trap mechanism, and allow for
 472   // a future recompilation if several traps occur here.
 473   // If the throw is hot, try to use a more complicated inline mechanism
 474   // which keeps execution inside the compiled code.
 475   bool treat_throw_as_hot = false;
 476   ciMethodData* md = method()->method_data();
 477 
 478   if (ProfileTraps) {
 479     if (too_many_traps(reason)) {
 480       treat_throw_as_hot = true;
 481     }
 482     // (If there is no MDO at all, assume it is early in
 483     // execution, and that any deopts are part of the
 484     // startup transient, and don't need to be remembered.)
 485 
 486     // Also, if there is a local exception handler, treat all throws
 487     // as hot if there has been at least one in this method.
 488     if (C->trap_count(reason) != 0
 489         && method()->method_data()->trap_count(reason) != 0
 490         && has_ex_handler()) {
 491         treat_throw_as_hot = true;
 492     }
 493   }
 494 
 495   // If this throw happens frequently, an uncommon trap might cause
 496   // a performance pothole.  If there is a local exception handler,
 497   // and if this particular bytecode appears to be deoptimizing often,
 498   // let us handle the throw inline, with a preconstructed instance.
 499   // Note:   If the deopt count has blown up, the uncommon trap
 500   // runtime is going to flush this nmethod, not matter what.
 501   if (treat_throw_as_hot
 502       && (!StackTraceInThrowable || OmitStackTraceInFastThrow)) {
 503     // If the throw is local, we use a pre-existing instance and
 504     // punt on the backtrace.  This would lead to a missing backtrace
 505     // (a repeat of 4292742) if the backtrace object is ever asked
 506     // for its backtrace.
 507     // Fixing this remaining case of 4292742 requires some flavor of
 508     // escape analysis.  Leave that for the future.
 509     ciInstance* ex_obj = NULL;
 510     switch (reason) {
 511     case Deoptimization::Reason_null_check:
 512       ex_obj = env()->NullPointerException_instance();
 513       break;
 514     case Deoptimization::Reason_div0_check:
 515       ex_obj = env()->ArithmeticException_instance();
 516       break;
 517     case Deoptimization::Reason_range_check:
 518       ex_obj = env()->ArrayIndexOutOfBoundsException_instance();
 519       break;
 520     case Deoptimization::Reason_class_check:
 521       if (java_bc() == Bytecodes::_aastore) {
 522         ex_obj = env()->ArrayStoreException_instance();
 523       } else {
 524         ex_obj = env()->ClassCastException_instance();
 525       }
 526       break;
 527     }
 528     if (failing()) { stop(); return; }  // exception allocation might fail
 529     if (ex_obj != NULL) {
 530       // Cheat with a preallocated exception object.
 531       if (C->log() != NULL)
 532         C->log()->elem("hot_throw preallocated='1' reason='%s'",
 533                        Deoptimization::trap_reason_name(reason));
 534       const TypeInstPtr* ex_con  = TypeInstPtr::make(ex_obj);
 535       Node*              ex_node = _gvn.transform( ConNode::make(C, ex_con) );
 536 
 537       // Clear the detail message of the preallocated exception object.
 538       // Weblogic sometimes mutates the detail message of exceptions
 539       // using reflection.
 540       int offset = java_lang_Throwable::get_detailMessage_offset();
 541       const TypePtr* adr_typ = ex_con->add_offset(offset);
 542 
 543       Node *adr = basic_plus_adr(ex_node, ex_node, offset);
 544       Node *store = store_oop_to_object(control(), ex_node, adr, adr_typ, null(), ex_con, T_OBJECT);
 545 
 546       add_exception_state(make_exception_state(ex_node));
 547       return;
 548     }
 549   }
 550 
 551   // %%% Maybe add entry to OptoRuntime which directly throws the exc.?
 552   // It won't be much cheaper than bailing to the interp., since we'll
 553   // have to pass up all the debug-info, and the runtime will have to
 554   // create the stack trace.
 555 
 556   // Usual case:  Bail to interpreter.
 557   // Reserve the right to recompile if we haven't seen anything yet.
 558 
 559   Deoptimization::DeoptAction action = Deoptimization::Action_maybe_recompile;
 560   if (treat_throw_as_hot
 561       && (method()->method_data()->trap_recompiled_at(bci())
 562           || C->too_many_traps(reason))) {
 563     // We cannot afford to take more traps here.  Suffer in the interpreter.
 564     if (C->log() != NULL)
 565       C->log()->elem("hot_throw preallocated='0' reason='%s' mcount='%d'",
 566                      Deoptimization::trap_reason_name(reason),
 567                      C->trap_count(reason));
 568     action = Deoptimization::Action_none;
 569   }
 570 
 571   // "must_throw" prunes the JVM state to include only the stack, if there
 572   // are no local exception handlers.  This should cut down on register
 573   // allocation time and code size, by drastically reducing the number
 574   // of in-edges on the call to the uncommon trap.
 575 
 576   uncommon_trap(reason, action, (ciKlass*)NULL, (char*)NULL, must_throw);
 577 }
 578 
 579 
 580 //----------------------------PreserveJVMState---------------------------------
 581 PreserveJVMState::PreserveJVMState(GraphKit* kit, bool clone_map) {
 582   debug_only(kit->verify_map());
 583   _kit    = kit;
 584   _map    = kit->map();   // preserve the map
 585   _sp     = kit->sp();
 586   kit->set_map(clone_map ? kit->clone_map() : NULL);
 587 #ifdef ASSERT
 588   _bci    = kit->bci();
 589   Parse* parser = kit->is_Parse();
 590   int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo();
 591   _block  = block;
 592 #endif
 593 }
 594 PreserveJVMState::~PreserveJVMState() {
 595   GraphKit* kit = _kit;
 596 #ifdef ASSERT
 597   assert(kit->bci() == _bci, "bci must not shift");
 598   Parse* parser = kit->is_Parse();
 599   int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo();
 600   assert(block == _block,    "block must not shift");
 601 #endif
 602   kit->set_map(_map);
 603   kit->set_sp(_sp);
 604 }
 605 
 606 
 607 //-----------------------------BuildCutout-------------------------------------
 608 BuildCutout::BuildCutout(GraphKit* kit, Node* p, float prob, float cnt)
 609   : PreserveJVMState(kit)
 610 {
 611   assert(p->is_Con() || p->is_Bool(), "test must be a bool");
 612   SafePointNode* outer_map = _map;   // preserved map is caller's
 613   SafePointNode* inner_map = kit->map();
 614   IfNode* iff = kit->create_and_map_if(outer_map->control(), p, prob, cnt);
 615   outer_map->set_control(kit->gvn().transform( new (kit->C, 1) IfTrueNode(iff) ));
 616   inner_map->set_control(kit->gvn().transform( new (kit->C, 1) IfFalseNode(iff) ));
 617 }
 618 BuildCutout::~BuildCutout() {
 619   GraphKit* kit = _kit;
 620   assert(kit->stopped(), "cutout code must stop, throw, return, etc.");
 621 }
 622 
 623 //---------------------------PreserveReexecuteAndSP----------------------------
 624 PreserveReexecuteAndSP::PreserveReexecuteAndSP(GraphKit* kit) {
 625   _kit    =    kit;
 626   _sp     =    kit->sp();
 627   _reexecute = kit->jvms()->should_reexecute();
 628 }
 629 PreserveReexecuteAndSP::~PreserveReexecuteAndSP() {
 630   _kit->jvms()->set_reexecute(_reexecute);
 631   _kit->set_sp(_sp);
 632 }
 633 
 634 //------------------------------clone_map--------------------------------------
 635 // Implementation of PreserveJVMState
 636 //
 637 // Only clone_map(...) here. If this function is only used in the
 638 // PreserveJVMState class we may want to get rid of this extra
 639 // function eventually and do it all there.
 640 
 641 SafePointNode* GraphKit::clone_map() {
 642   if (map() == NULL)  return NULL;
 643 
 644   // Clone the memory edge first
 645   Node* mem = MergeMemNode::make(C, map()->memory());
 646   gvn().set_type_bottom(mem);
 647 
 648   SafePointNode *clonemap = (SafePointNode*)map()->clone();
 649   JVMState* jvms = this->jvms();
 650   JVMState* clonejvms = jvms->clone_shallow(C);
 651   clonemap->set_memory(mem);
 652   clonemap->set_jvms(clonejvms);
 653   clonejvms->set_map(clonemap);
 654   record_for_igvn(clonemap);
 655   gvn().set_type_bottom(clonemap);
 656   return clonemap;
 657 }
 658 
 659 
 660 //-----------------------------set_map_clone-----------------------------------
 661 void GraphKit::set_map_clone(SafePointNode* m) {
 662   _map = m;
 663   _map = clone_map();
 664   _map->set_next_exception(NULL);
 665   debug_only(verify_map());
 666 }
 667 
 668 
 669 //----------------------------kill_dead_locals---------------------------------
 670 // Detect any locals which are known to be dead, and force them to top.
 671 void GraphKit::kill_dead_locals() {
 672   // Consult the liveness information for the locals.  If any
 673   // of them are unused, then they can be replaced by top().  This
 674   // should help register allocation time and cut down on the size
 675   // of the deoptimization information.
 676 
 677   // This call is made from many of the bytecode handling
 678   // subroutines called from the Big Switch in do_one_bytecode.
 679   // Every bytecode which might include a slow path is responsible
 680   // for killing its dead locals.  The more consistent we
 681   // are about killing deads, the fewer useless phis will be
 682   // constructed for them at various merge points.
 683 
 684   // bci can be -1 (InvocationEntryBci).  We return the entry
 685   // liveness for the method.
 686 
 687   if (method() == NULL || method()->code_size() == 0) {
 688     // We are building a graph for a call to a native method.
 689     // All locals are live.
 690     return;
 691   }
 692 
 693   ResourceMark rm;
 694 
 695   // Consult the liveness information for the locals.  If any
 696   // of them are unused, then they can be replaced by top().  This
 697   // should help register allocation time and cut down on the size
 698   // of the deoptimization information.
 699   MethodLivenessResult live_locals = method()->liveness_at_bci(bci());
 700 
 701   int len = (int)live_locals.size();
 702   assert(len <= jvms()->loc_size(), "too many live locals");
 703   for (int local = 0; local < len; local++) {
 704     if (!live_locals.at(local)) {
 705       set_local(local, top());
 706     }
 707   }
 708 }
 709 
 710 #ifdef ASSERT
 711 //-------------------------dead_locals_are_killed------------------------------
 712 // Return true if all dead locals are set to top in the map.
 713 // Used to assert "clean" debug info at various points.
 714 bool GraphKit::dead_locals_are_killed() {
 715   if (method() == NULL || method()->code_size() == 0) {
 716     // No locals need to be dead, so all is as it should be.
 717     return true;
 718   }
 719 
 720   // Make sure somebody called kill_dead_locals upstream.
 721   ResourceMark rm;
 722   for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) {
 723     if (jvms->loc_size() == 0)  continue;  // no locals to consult
 724     SafePointNode* map = jvms->map();
 725     ciMethod* method = jvms->method();
 726     int       bci    = jvms->bci();
 727     if (jvms == this->jvms()) {
 728       bci = this->bci();  // it might not yet be synched
 729     }
 730     MethodLivenessResult live_locals = method->liveness_at_bci(bci);
 731     int len = (int)live_locals.size();
 732     if (!live_locals.is_valid() || len == 0)
 733       // This method is trivial, or is poisoned by a breakpoint.
 734       return true;
 735     assert(len == jvms->loc_size(), "live map consistent with locals map");
 736     for (int local = 0; local < len; local++) {
 737       if (!live_locals.at(local) && map->local(jvms, local) != top()) {
 738         if (PrintMiscellaneous && (Verbose || WizardMode)) {
 739           tty->print_cr("Zombie local %d: ", local);
 740           jvms->dump();
 741         }
 742         return false;
 743       }
 744     }
 745   }
 746   return true;
 747 }
 748 
 749 #endif //ASSERT
 750 
 751 // Helper function for enforcing certain bytecodes to reexecute if 
 752 // deoptimization happens
 753 static bool should_reexecute_implied_by_bytecodes(JVMState *jvms) {
 754   ciMethod* cur_method = jvms->method();
 755   int       cur_bci   = jvms->bci();
 756   if (cur_method != NULL && cur_bci != InvocationEntryBci) {
 757     Bytecodes::Code code = cur_method->java_code_at_bci(cur_bci);
 758     return Interpreter::bytecodes_to_reexecute(code);
 759   } else
 760     return false;
 761 }
 762 
 763 // Helper function for adding JVMState and debug information to node
 764 void GraphKit::add_safepoint_edges(SafePointNode* call, bool must_throw) {
 765   // Add the safepoint edges to the call (or other safepoint).
 766 
 767   // Make sure dead locals are set to top.  This
 768   // should help register allocation time and cut down on the size
 769   // of the deoptimization information.
 770   assert(dead_locals_are_killed(), "garbage in debug info before safepoint");
 771 
 772   // Walk the inline list to fill in the correct set of JVMState's
 773   // Also fill in the associated edges for each JVMState.
 774 
 775   JVMState* youngest_jvms = sync_jvms();
 776 
 777   // Do we need debug info here?  If it is a SafePoint and this method
 778   // cannot de-opt, then we do NOT need any debug info.
 779   bool full_info = (C->deopt_happens() || call->Opcode() != Op_SafePoint);
 780 
 781   // If we are guaranteed to throw, we can prune everything but the
 782   // input to the current bytecode.
 783   bool can_prune_locals = false;
 784   uint stack_slots_not_pruned = 0;
 785   int inputs = 0, depth = 0;
 786   if (must_throw) {
 787     assert(method() == youngest_jvms->method(), "sanity");
 788     if (compute_stack_effects(inputs, depth)) {
 789       can_prune_locals = true;
 790       stack_slots_not_pruned = inputs;
 791     }
 792   }
 793 
 794   if (env()->jvmti_can_examine_or_deopt_anywhere()) {
 795     // At any safepoint, this method can get breakpointed, which would
 796     // then require an immediate deoptimization.
 797     full_info = true;
 798     can_prune_locals = false;  // do not prune locals
 799     stack_slots_not_pruned = 0;
 800   }
 801 
 802   // do not scribble on the input jvms
 803   JVMState* out_jvms = youngest_jvms->clone_deep(C);
 804   call->set_jvms(out_jvms); // Start jvms list for call node
 805 
 806   // For a known set of bytecodes, the interpreter must reexecute them if
 807   // deoptimization happens. We set the reexecute bit for them here
 808   if(should_reexecute_implied_by_bytecodes(out_jvms))
 809     out_jvms->set_reexecute(true);
 810 
 811   // Presize the call:
 812   debug_only(uint non_debug_edges = call->req());
 813   call->add_req_batch(top(), youngest_jvms->debug_depth());
 814   assert(call->req() == non_debug_edges + youngest_jvms->debug_depth(), "");
 815 
 816   // Set up edges so that the call looks like this:
 817   //  Call [state:] ctl io mem fptr retadr
 818   //       [parms:] parm0 ... parmN
 819   //       [root:]  loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN
 820   //    [...mid:]   loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN [...]
 821   //       [young:] loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN
 822   // Note that caller debug info precedes callee debug info.
 823 
 824   // Fill pointer walks backwards from "young:" to "root:" in the diagram above:
 825   uint debug_ptr = call->req();
 826 
 827   // Loop over the map input edges associated with jvms, add them
 828   // to the call node, & reset all offsets to match call node array.
 829   for (JVMState* in_jvms = youngest_jvms; in_jvms != NULL; ) {
 830     uint debug_end   = debug_ptr;
 831     uint debug_start = debug_ptr - in_jvms->debug_size();
 832     debug_ptr = debug_start;  // back up the ptr
 833 
 834     uint p = debug_start;  // walks forward in [debug_start, debug_end)
 835     uint j, k, l;
 836     SafePointNode* in_map = in_jvms->map();
 837     out_jvms->set_map(call);
 838 
 839     if (can_prune_locals) {
 840       assert(in_jvms->method() == out_jvms->method(), "sanity");
 841       // If the current throw can reach an exception handler in this JVMS,
 842       // then we must keep everything live that can reach that handler.
 843       // As a quick and dirty approximation, we look for any handlers at all.
 844       if (in_jvms->method()->has_exception_handlers()) {
 845         can_prune_locals = false;
 846       }
 847     }
 848 
 849     // Add the Locals
 850     k = in_jvms->locoff();
 851     l = in_jvms->loc_size();
 852     out_jvms->set_locoff(p);
 853     if (full_info && !can_prune_locals) {
 854       for (j = 0; j < l; j++)
 855         call->set_req(p++, in_map->in(k+j));
 856     } else {
 857       p += l;  // already set to top above by add_req_batch
 858     }
 859 
 860     // Add the Expression Stack
 861     k = in_jvms->stkoff();
 862     l = in_jvms->sp();
 863     out_jvms->set_stkoff(p);
 864     if (full_info && !can_prune_locals) {
 865       for (j = 0; j < l; j++)
 866         call->set_req(p++, in_map->in(k+j));
 867     } else if (can_prune_locals && stack_slots_not_pruned != 0) {
 868       // Divide stack into {S0,...,S1}, where S0 is set to top.
 869       uint s1 = stack_slots_not_pruned;
 870       stack_slots_not_pruned = 0;  // for next iteration
 871       if (s1 > l)  s1 = l;
 872       uint s0 = l - s1;
 873       p += s0;  // skip the tops preinstalled by add_req_batch
 874       for (j = s0; j < l; j++)
 875         call->set_req(p++, in_map->in(k+j));
 876     } else {
 877       p += l;  // already set to top above by add_req_batch
 878     }
 879 
 880     // Add the Monitors
 881     k = in_jvms->monoff();
 882     l = in_jvms->mon_size();
 883     out_jvms->set_monoff(p);
 884     for (j = 0; j < l; j++)
 885       call->set_req(p++, in_map->in(k+j));
 886 
 887     // Copy any scalar object fields.
 888     k = in_jvms->scloff();
 889     l = in_jvms->scl_size();
 890     out_jvms->set_scloff(p);
 891     for (j = 0; j < l; j++)
 892       call->set_req(p++, in_map->in(k+j));
 893 
 894     // Finish the new jvms.
 895     out_jvms->set_endoff(p);
 896 
 897     assert(out_jvms->endoff()     == debug_end,             "fill ptr must match");
 898     assert(out_jvms->depth()      == in_jvms->depth(),      "depth must match");
 899     assert(out_jvms->loc_size()   == in_jvms->loc_size(),   "size must match");
 900     assert(out_jvms->mon_size()   == in_jvms->mon_size(),   "size must match");
 901     assert(out_jvms->scl_size()   == in_jvms->scl_size(),   "size must match");
 902     assert(out_jvms->debug_size() == in_jvms->debug_size(), "size must match");
 903 
 904     // Update the two tail pointers in parallel.
 905     out_jvms = out_jvms->caller();
 906     in_jvms  = in_jvms->caller();
 907   }
 908 
 909   assert(debug_ptr == non_debug_edges, "debug info must fit exactly");
 910 
 911   // Test the correctness of JVMState::debug_xxx accessors:
 912   assert(call->jvms()->debug_start() == non_debug_edges, "");
 913   assert(call->jvms()->debug_end()   == call->req(), "");
 914   assert(call->jvms()->debug_depth() == call->req() - non_debug_edges, "");
 915 }
 916 
 917 bool GraphKit::compute_stack_effects(int& inputs, int& depth) {
 918   Bytecodes::Code code = java_bc();
 919   if (code == Bytecodes::_wide) {
 920     code = method()->java_code_at_bci(bci() + 1);
 921   }
 922 
 923   BasicType rtype = T_ILLEGAL;
 924   int       rsize = 0;
 925 
 926   if (code != Bytecodes::_illegal) {
 927     depth = Bytecodes::depth(code); // checkcast=0, athrow=-1
 928     rtype = Bytecodes::result_type(code); // checkcast=P, athrow=V
 929     if (rtype < T_CONFLICT)
 930       rsize = type2size[rtype];
 931   }
 932 
 933   switch (code) {
 934   case Bytecodes::_illegal:
 935     return false;
 936 
 937   case Bytecodes::_ldc:
 938   case Bytecodes::_ldc_w:
 939   case Bytecodes::_ldc2_w:
 940     inputs = 0;
 941     break;
 942 
 943   case Bytecodes::_dup:         inputs = 1;  break;
 944   case Bytecodes::_dup_x1:      inputs = 2;  break;
 945   case Bytecodes::_dup_x2:      inputs = 3;  break;
 946   case Bytecodes::_dup2:        inputs = 2;  break;
 947   case Bytecodes::_dup2_x1:     inputs = 3;  break;
 948   case Bytecodes::_dup2_x2:     inputs = 4;  break;
 949   case Bytecodes::_swap:        inputs = 2;  break;
 950   case Bytecodes::_arraylength: inputs = 1;  break;
 951 
 952   case Bytecodes::_getstatic:
 953   case Bytecodes::_putstatic:
 954   case Bytecodes::_getfield:
 955   case Bytecodes::_putfield:
 956     {
 957       bool is_get = (depth >= 0), is_static = (depth & 1);
 958       bool ignore;
 959       ciBytecodeStream iter(method());
 960       iter.reset_to_bci(bci());
 961       iter.next();
 962       ciField* field = iter.get_field(ignore);
 963       int      size  = field->type()->size();
 964       inputs  = (is_static ? 0 : 1);
 965       if (is_get) {
 966         depth = size - inputs;
 967       } else {
 968         inputs += size;        // putxxx pops the value from the stack
 969         depth = - inputs;
 970       }
 971     }
 972     break;
 973 
 974   case Bytecodes::_invokevirtual:
 975   case Bytecodes::_invokespecial:
 976   case Bytecodes::_invokestatic:
 977   case Bytecodes::_invokedynamic:
 978   case Bytecodes::_invokeinterface:
 979     {
 980       bool is_static = (depth == 0);
 981       bool ignore;
 982       ciBytecodeStream iter(method());
 983       iter.reset_to_bci(bci());
 984       iter.next();
 985       ciMethod* method = iter.get_method(ignore);
 986       inputs = method->arg_size_no_receiver();
 987       if (!is_static)  inputs += 1;
 988       int size = method->return_type()->size();
 989       depth = size - inputs;
 990     }
 991     break;
 992 
 993   case Bytecodes::_multianewarray:
 994     {
 995       ciBytecodeStream iter(method());
 996       iter.reset_to_bci(bci());
 997       iter.next();
 998       inputs = iter.get_dimensions();
 999       assert(rsize == 1, "");
1000       depth = rsize - inputs;
1001     }
1002     break;
1003 
1004   case Bytecodes::_ireturn:
1005   case Bytecodes::_lreturn:
1006   case Bytecodes::_freturn:
1007   case Bytecodes::_dreturn:
1008   case Bytecodes::_areturn:
1009     assert(rsize = -depth, "");
1010     inputs = rsize;
1011     break;
1012 
1013   case Bytecodes::_jsr:
1014   case Bytecodes::_jsr_w:
1015     inputs = 0;
1016     depth  = 1;                  // S.B. depth=1, not zero
1017     break;
1018 
1019   default:
1020     // bytecode produces a typed result
1021     inputs = rsize - depth;
1022     assert(inputs >= 0, "");
1023     break;
1024   }
1025 
1026 #ifdef ASSERT
1027   // spot check
1028   int outputs = depth + inputs;
1029   assert(outputs >= 0, "sanity");
1030   switch (code) {
1031   case Bytecodes::_checkcast: assert(inputs == 1 && outputs == 1, ""); break;
1032   case Bytecodes::_athrow:    assert(inputs == 1 && outputs == 0, ""); break;
1033   case Bytecodes::_aload_0:   assert(inputs == 0 && outputs == 1, ""); break;
1034   case Bytecodes::_return:    assert(inputs == 0 && outputs == 0, ""); break;
1035   case Bytecodes::_drem:      assert(inputs == 4 && outputs == 2, ""); break;
1036   }
1037 #endif //ASSERT
1038 
1039   return true;
1040 }
1041 
1042 
1043 
1044 //------------------------------basic_plus_adr---------------------------------
1045 Node* GraphKit::basic_plus_adr(Node* base, Node* ptr, Node* offset) {
1046   // short-circuit a common case
1047   if (offset == intcon(0))  return ptr;
1048   return _gvn.transform( new (C, 4) AddPNode(base, ptr, offset) );
1049 }
1050 
1051 Node* GraphKit::ConvI2L(Node* offset) {
1052   // short-circuit a common case
1053   jint offset_con = find_int_con(offset, Type::OffsetBot);
1054   if (offset_con != Type::OffsetBot) {
1055     return longcon((long) offset_con);
1056   }
1057   return _gvn.transform( new (C, 2) ConvI2LNode(offset));
1058 }
1059 Node* GraphKit::ConvL2I(Node* offset) {
1060   // short-circuit a common case
1061   jlong offset_con = find_long_con(offset, (jlong)Type::OffsetBot);
1062   if (offset_con != (jlong)Type::OffsetBot) {
1063     return intcon((int) offset_con);
1064   }
1065   return _gvn.transform( new (C, 2) ConvL2INode(offset));
1066 }
1067 
1068 //-------------------------load_object_klass-----------------------------------
1069 Node* GraphKit::load_object_klass(Node* obj) {
1070   // Special-case a fresh allocation to avoid building nodes:
1071   Node* akls = AllocateNode::Ideal_klass(obj, &_gvn);
1072   if (akls != NULL)  return akls;
1073   Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes());
1074   return _gvn.transform( LoadKlassNode::make(_gvn, immutable_memory(), k_adr, TypeInstPtr::KLASS) );
1075 }
1076 
1077 //-------------------------load_array_length-----------------------------------
1078 Node* GraphKit::load_array_length(Node* array) {
1079   // Special-case a fresh allocation to avoid building nodes:
1080   AllocateArrayNode* alloc = AllocateArrayNode::Ideal_array_allocation(array, &_gvn);
1081   Node *alen;
1082   if (alloc == NULL) {
1083     Node *r_adr = basic_plus_adr(array, arrayOopDesc::length_offset_in_bytes());
1084     alen = _gvn.transform( new (C, 3) LoadRangeNode(0, immutable_memory(), r_adr, TypeInt::POS));
1085   } else {
1086     alen = alloc->Ideal_length();
1087     Node* ccast = alloc->make_ideal_length(_gvn.type(array)->is_aryptr(), &_gvn);
1088     if (ccast != alen) {
1089       alen = _gvn.transform(ccast);
1090     }
1091   }
1092   return alen;
1093 }
1094 
1095 //------------------------------do_null_check----------------------------------
1096 // Helper function to do a NULL pointer check.  Returned value is
1097 // the incoming address with NULL casted away.  You are allowed to use the
1098 // not-null value only if you are control dependent on the test.
1099 extern int explicit_null_checks_inserted,
1100            explicit_null_checks_elided;
1101 Node* GraphKit::null_check_common(Node* value, BasicType type,
1102                                   // optional arguments for variations:
1103                                   bool assert_null,
1104                                   Node* *null_control) {
1105   assert(!assert_null || null_control == NULL, "not both at once");
1106   if (stopped())  return top();
1107   if (!GenerateCompilerNullChecks && !assert_null && null_control == NULL) {
1108     // For some performance testing, we may wish to suppress null checking.
1109     value = cast_not_null(value);   // Make it appear to be non-null (4962416).
1110     return value;
1111   }
1112   explicit_null_checks_inserted++;
1113 
1114   // Construct NULL check
1115   Node *chk = NULL;
1116   switch(type) {
1117     case T_LONG   : chk = new (C, 3) CmpLNode(value, _gvn.zerocon(T_LONG)); break;
1118     case T_INT    : chk = new (C, 3) CmpINode( value, _gvn.intcon(0)); break;
1119     case T_ARRAY  : // fall through
1120       type = T_OBJECT;  // simplify further tests
1121     case T_OBJECT : {
1122       const Type *t = _gvn.type( value );
1123 
1124       const TypeInstPtr* tp = t->isa_instptr();
1125       if (tp != NULL && !tp->klass()->is_loaded()
1126           // Only for do_null_check, not any of its siblings:
1127           && !assert_null && null_control == NULL) {
1128         // Usually, any field access or invocation on an unloaded oop type
1129         // will simply fail to link, since the statically linked class is
1130         // likely also to be unloaded.  However, in -Xcomp mode, sometimes
1131         // the static class is loaded but the sharper oop type is not.
1132         // Rather than checking for this obscure case in lots of places,
1133         // we simply observe that a null check on an unloaded class
1134         // will always be followed by a nonsense operation, so we
1135         // can just issue the uncommon trap here.
1136         // Our access to the unloaded class will only be correct
1137         // after it has been loaded and initialized, which requires
1138         // a trip through the interpreter.
1139 #ifndef PRODUCT
1140         if (WizardMode) { tty->print("Null check of unloaded "); tp->klass()->print(); tty->cr(); }
1141 #endif
1142         uncommon_trap(Deoptimization::Reason_unloaded,
1143                       Deoptimization::Action_reinterpret,
1144                       tp->klass(), "!loaded");
1145         return top();
1146       }
1147 
1148       if (assert_null) {
1149         // See if the type is contained in NULL_PTR.
1150         // If so, then the value is already null.
1151         if (t->higher_equal(TypePtr::NULL_PTR)) {
1152           explicit_null_checks_elided++;
1153           return value;           // Elided null assert quickly!
1154         }
1155       } else {
1156         // See if mixing in the NULL pointer changes type.
1157         // If so, then the NULL pointer was not allowed in the original
1158         // type.  In other words, "value" was not-null.
1159         if (t->meet(TypePtr::NULL_PTR) != t) {
1160           // same as: if (!TypePtr::NULL_PTR->higher_equal(t)) ...
1161           explicit_null_checks_elided++;
1162           return value;           // Elided null check quickly!
1163         }
1164       }
1165       chk = new (C, 3) CmpPNode( value, null() );
1166       break;
1167     }
1168 
1169     default      : ShouldNotReachHere();
1170   }
1171   assert(chk != NULL, "sanity check");
1172   chk = _gvn.transform(chk);
1173 
1174   BoolTest::mask btest = assert_null ? BoolTest::eq : BoolTest::ne;
1175   BoolNode *btst = new (C, 2) BoolNode( chk, btest);
1176   Node   *tst = _gvn.transform( btst );
1177 
1178   //-----------
1179   // if peephole optimizations occurred, a prior test existed.
1180   // If a prior test existed, maybe it dominates as we can avoid this test.
1181   if (tst != btst && type == T_OBJECT) {
1182     // At this point we want to scan up the CFG to see if we can
1183     // find an identical test (and so avoid this test altogether).
1184     Node *cfg = control();
1185     int depth = 0;
1186     while( depth < 16 ) {       // Limit search depth for speed
1187       if( cfg->Opcode() == Op_IfTrue &&
1188           cfg->in(0)->in(1) == tst ) {
1189         // Found prior test.  Use "cast_not_null" to construct an identical
1190         // CastPP (and hence hash to) as already exists for the prior test.
1191         // Return that casted value.
1192         if (assert_null) {
1193           replace_in_map(value, null());
1194           return null();  // do not issue the redundant test
1195         }
1196         Node *oldcontrol = control();
1197         set_control(cfg);
1198         Node *res = cast_not_null(value);
1199         set_control(oldcontrol);
1200         explicit_null_checks_elided++;
1201         return res;
1202       }
1203       cfg = IfNode::up_one_dom(cfg, /*linear_only=*/ true);
1204       if (cfg == NULL)  break;  // Quit at region nodes
1205       depth++;
1206     }
1207   }
1208 
1209   //-----------
1210   // Branch to failure if null
1211   float ok_prob = PROB_MAX;  // a priori estimate:  nulls never happen
1212   Deoptimization::DeoptReason reason;
1213   if (assert_null)
1214     reason = Deoptimization::Reason_null_assert;
1215   else if (type == T_OBJECT)
1216     reason = Deoptimization::Reason_null_check;
1217   else
1218     reason = Deoptimization::Reason_div0_check;
1219 
1220   // %%% Since Reason_unhandled is not recorded on a per-bytecode basis,
1221   // ciMethodData::has_trap_at will return a conservative -1 if any
1222   // must-be-null assertion has failed.  This could cause performance
1223   // problems for a method after its first do_null_assert failure.
1224   // Consider using 'Reason_class_check' instead?
1225 
1226   // To cause an implicit null check, we set the not-null probability
1227   // to the maximum (PROB_MAX).  For an explicit check the probability
1228   // is set to a smaller value.
1229   if (null_control != NULL || too_many_traps(reason)) {
1230     // probability is less likely
1231     ok_prob =  PROB_LIKELY_MAG(3);
1232   } else if (!assert_null &&
1233              (ImplicitNullCheckThreshold > 0) &&
1234              method() != NULL &&
1235              (method()->method_data()->trap_count(reason)
1236               >= (uint)ImplicitNullCheckThreshold)) {
1237     ok_prob =  PROB_LIKELY_MAG(3);
1238   }
1239 
1240   if (null_control != NULL) {
1241     IfNode* iff = create_and_map_if(control(), tst, ok_prob, COUNT_UNKNOWN);
1242     Node* null_true = _gvn.transform( new (C, 1) IfFalseNode(iff));
1243     set_control(      _gvn.transform( new (C, 1) IfTrueNode(iff)));
1244     if (null_true == top())
1245       explicit_null_checks_elided++;
1246     (*null_control) = null_true;
1247   } else {
1248     BuildCutout unless(this, tst, ok_prob);
1249     // Check for optimizer eliding test at parse time
1250     if (stopped()) {
1251       // Failure not possible; do not bother making uncommon trap.
1252       explicit_null_checks_elided++;
1253     } else if (assert_null) {
1254       uncommon_trap(reason,
1255                     Deoptimization::Action_make_not_entrant,
1256                     NULL, "assert_null");
1257     } else {
1258       replace_in_map(value, zerocon(type));
1259       builtin_throw(reason);
1260     }
1261   }
1262 
1263   // Must throw exception, fall-thru not possible?
1264   if (stopped()) {
1265     return top();               // No result
1266   }
1267 
1268   if (assert_null) {
1269     // Cast obj to null on this path.
1270     replace_in_map(value, zerocon(type));
1271     return zerocon(type);
1272   }
1273 
1274   // Cast obj to not-null on this path, if there is no null_control.
1275   // (If there is a null_control, a non-null value may come back to haunt us.)
1276   if (type == T_OBJECT) {
1277     Node* cast = cast_not_null(value, false);
1278     if (null_control == NULL || (*null_control) == top())
1279       replace_in_map(value, cast);
1280     value = cast;
1281   }
1282 
1283   return value;
1284 }
1285 
1286 
1287 //------------------------------cast_not_null----------------------------------
1288 // Cast obj to not-null on this path
1289 Node* GraphKit::cast_not_null(Node* obj, bool do_replace_in_map) {
1290   const Type *t = _gvn.type(obj);
1291   const Type *t_not_null = t->join(TypePtr::NOTNULL);
1292   // Object is already not-null?
1293   if( t == t_not_null ) return obj;
1294 
1295   Node *cast = new (C, 2) CastPPNode(obj,t_not_null);
1296   cast->init_req(0, control());
1297   cast = _gvn.transform( cast );
1298 
1299   // Scan for instances of 'obj' in the current JVM mapping.
1300   // These instances are known to be not-null after the test.
1301   if (do_replace_in_map)
1302     replace_in_map(obj, cast);
1303 
1304   return cast;                  // Return casted value
1305 }
1306 
1307 
1308 //--------------------------replace_in_map-------------------------------------
1309 void GraphKit::replace_in_map(Node* old, Node* neww) {
1310   this->map()->replace_edge(old, neww);
1311 
1312   // Note: This operation potentially replaces any edge
1313   // on the map.  This includes locals, stack, and monitors
1314   // of the current (innermost) JVM state.
1315 
1316   // We can consider replacing in caller maps.
1317   // The idea would be that an inlined function's null checks
1318   // can be shared with the entire inlining tree.
1319   // The expense of doing this is that the PreserveJVMState class
1320   // would have to preserve caller states too, with a deep copy.
1321 }
1322 
1323 
1324 
1325 //=============================================================================
1326 //--------------------------------memory---------------------------------------
1327 Node* GraphKit::memory(uint alias_idx) {
1328   MergeMemNode* mem = merged_memory();
1329   Node* p = mem->memory_at(alias_idx);
1330   _gvn.set_type(p, Type::MEMORY);  // must be mapped
1331   return p;
1332 }
1333 
1334 //-----------------------------reset_memory------------------------------------
1335 Node* GraphKit::reset_memory() {
1336   Node* mem = map()->memory();
1337   // do not use this node for any more parsing!
1338   debug_only( map()->set_memory((Node*)NULL) );
1339   return _gvn.transform( mem );
1340 }
1341 
1342 //------------------------------set_all_memory---------------------------------
1343 void GraphKit::set_all_memory(Node* newmem) {
1344   Node* mergemem = MergeMemNode::make(C, newmem);
1345   gvn().set_type_bottom(mergemem);
1346   map()->set_memory(mergemem);
1347 }
1348 
1349 //------------------------------set_all_memory_call----------------------------
1350 void GraphKit::set_all_memory_call(Node* call) {
1351   Node* newmem = _gvn.transform( new (C, 1) ProjNode(call, TypeFunc::Memory) );
1352   set_all_memory(newmem);
1353 }
1354 
1355 //=============================================================================
1356 //
1357 // parser factory methods for MemNodes
1358 //
1359 // These are layered on top of the factory methods in LoadNode and StoreNode,
1360 // and integrate with the parser's memory state and _gvn engine.
1361 //
1362 
1363 // factory methods in "int adr_idx"
1364 Node* GraphKit::make_load(Node* ctl, Node* adr, const Type* t, BasicType bt,
1365                           int adr_idx,
1366                           bool require_atomic_access) {
1367   assert(adr_idx != Compile::AliasIdxTop, "use other make_load factory" );
1368   const TypePtr* adr_type = NULL; // debug-mode-only argument
1369   debug_only(adr_type = C->get_adr_type(adr_idx));
1370   Node* mem = memory(adr_idx);
1371   Node* ld;
1372   if (require_atomic_access && bt == T_LONG) {
1373     ld = LoadLNode::make_atomic(C, ctl, mem, adr, adr_type, t);
1374   } else {
1375     ld = LoadNode::make(_gvn, ctl, mem, adr, adr_type, t, bt);
1376   }
1377   return _gvn.transform(ld);
1378 }
1379 
1380 Node* GraphKit::store_to_memory(Node* ctl, Node* adr, Node *val, BasicType bt,
1381                                 int adr_idx,
1382                                 bool require_atomic_access) {
1383   assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
1384   const TypePtr* adr_type = NULL;
1385   debug_only(adr_type = C->get_adr_type(adr_idx));
1386   Node *mem = memory(adr_idx);
1387   Node* st;
1388   if (require_atomic_access && bt == T_LONG) {
1389     st = StoreLNode::make_atomic(C, ctl, mem, adr, adr_type, val);
1390   } else {
1391     st = StoreNode::make(_gvn, ctl, mem, adr, adr_type, val, bt);
1392   }
1393   st = _gvn.transform(st);
1394   set_memory(st, adr_idx);
1395   // Back-to-back stores can only remove intermediate store with DU info
1396   // so push on worklist for optimizer.
1397   if (mem->req() > MemNode::Address && adr == mem->in(MemNode::Address))
1398     record_for_igvn(st);
1399 
1400   return st;
1401 }
1402 
1403 void GraphKit::pre_barrier(Node* ctl,
1404                            Node* obj,
1405                            Node* adr,
1406                            uint adr_idx,
1407                            Node *val,
1408                            const TypeOopPtr* val_type,
1409                            BasicType bt) {
1410   BarrierSet* bs = Universe::heap()->barrier_set();
1411   set_control(ctl);
1412   switch (bs->kind()) {
1413     case BarrierSet::G1SATBCT:
1414     case BarrierSet::G1SATBCTLogging:
1415         g1_write_barrier_pre(obj, adr, adr_idx, val, val_type, bt);
1416       break;
1417 
1418     case BarrierSet::CardTableModRef:
1419     case BarrierSet::CardTableExtension:
1420     case BarrierSet::ModRef:
1421       break;
1422 
1423     case BarrierSet::Other:
1424     default      :
1425       ShouldNotReachHere();
1426 
1427   }
1428 }
1429 
1430 void GraphKit::post_barrier(Node* ctl,
1431                             Node* store,
1432                             Node* obj,
1433                             Node* adr,
1434                             uint adr_idx,
1435                             Node *val,
1436                             BasicType bt,
1437                             bool use_precise) {
1438   BarrierSet* bs = Universe::heap()->barrier_set();
1439   set_control(ctl);
1440   switch (bs->kind()) {
1441     case BarrierSet::G1SATBCT:
1442     case BarrierSet::G1SATBCTLogging:
1443         g1_write_barrier_post(store, obj, adr, adr_idx, val, bt, use_precise);
1444       break;
1445 
1446     case BarrierSet::CardTableModRef:
1447     case BarrierSet::CardTableExtension:
1448       write_barrier_post(store, obj, adr, val, use_precise);
1449       break;
1450 
1451     case BarrierSet::ModRef:
1452       break;
1453 
1454     case BarrierSet::Other:
1455     default      :
1456       ShouldNotReachHere();
1457 
1458   }
1459 }
1460 
1461 Node* GraphKit::store_oop_to_object(Node* ctl,
1462                                     Node* obj,
1463                                     Node* adr,
1464                                     const TypePtr* adr_type,
1465                                     Node *val,
1466                                     const TypeOopPtr* val_type,
1467                                     BasicType bt) {
1468   uint adr_idx = C->get_alias_index(adr_type);
1469   Node* store;
1470   pre_barrier(ctl, obj, adr, adr_idx, val, val_type, bt);
1471   store = store_to_memory(control(), adr, val, bt, adr_idx);
1472   post_barrier(control(), store, obj, adr, adr_idx, val, bt, false);
1473   return store;
1474 }
1475 
1476 Node* GraphKit::store_oop_to_array(Node* ctl,
1477                                    Node* obj,
1478                                    Node* adr,
1479                                    const TypePtr* adr_type,
1480                                    Node *val,
1481                                    const TypeOopPtr* val_type,
1482                                    BasicType bt) {
1483   uint adr_idx = C->get_alias_index(adr_type);
1484   Node* store;
1485   pre_barrier(ctl, obj, adr, adr_idx, val, val_type, bt);
1486   store = store_to_memory(control(), adr, val, bt, adr_idx);
1487   post_barrier(control(), store, obj, adr, adr_idx, val, bt, true);
1488   return store;
1489 }
1490 
1491 Node* GraphKit::store_oop_to_unknown(Node* ctl,
1492                                      Node* obj,
1493                                      Node* adr,
1494                                      const TypePtr* adr_type,
1495                                      Node *val,
1496                                      BasicType bt) {
1497   Compile::AliasType* at = C->alias_type(adr_type);
1498   const TypeOopPtr* val_type = NULL;
1499   if (adr_type->isa_instptr()) {
1500     if (at->field() != NULL) {
1501       // known field.  This code is a copy of the do_put_xxx logic.
1502       ciField* field = at->field();
1503       if (!field->type()->is_loaded()) {
1504         val_type = TypeInstPtr::BOTTOM;
1505       } else {
1506         val_type = TypeOopPtr::make_from_klass(field->type()->as_klass());
1507       }
1508     }
1509   } else if (adr_type->isa_aryptr()) {
1510     val_type = adr_type->is_aryptr()->elem()->make_oopptr();
1511   }
1512   if (val_type == NULL) {
1513     val_type = TypeInstPtr::BOTTOM;
1514   }
1515 
1516   uint adr_idx = at->index();
1517   pre_barrier(ctl, obj, adr, adr_idx, val, val_type, bt);
1518   Node* store = store_to_memory(control(), adr, val, bt, adr_idx);
1519   post_barrier(control(), store, obj, adr, adr_idx, val, bt, true);
1520   return store;
1521 }
1522 
1523 
1524 //-------------------------array_element_address-------------------------
1525 Node* GraphKit::array_element_address(Node* ary, Node* idx, BasicType elembt,
1526                                       const TypeInt* sizetype) {
1527   uint shift  = exact_log2(type2aelembytes(elembt));
1528   uint header = arrayOopDesc::base_offset_in_bytes(elembt);
1529 
1530   // short-circuit a common case (saves lots of confusing waste motion)
1531   jint idx_con = find_int_con(idx, -1);
1532   if (idx_con >= 0) {
1533     intptr_t offset = header + ((intptr_t)idx_con << shift);
1534     return basic_plus_adr(ary, offset);
1535   }
1536 
1537   // must be correct type for alignment purposes
1538   Node* base  = basic_plus_adr(ary, header);
1539 #ifdef _LP64
1540   // The scaled index operand to AddP must be a clean 64-bit value.
1541   // Java allows a 32-bit int to be incremented to a negative
1542   // value, which appears in a 64-bit register as a large
1543   // positive number.  Using that large positive number as an
1544   // operand in pointer arithmetic has bad consequences.
1545   // On the other hand, 32-bit overflow is rare, and the possibility
1546   // can often be excluded, if we annotate the ConvI2L node with
1547   // a type assertion that its value is known to be a small positive
1548   // number.  (The prior range check has ensured this.)
1549   // This assertion is used by ConvI2LNode::Ideal.
1550   int index_max = max_jint - 1;  // array size is max_jint, index is one less
1551   if (sizetype != NULL)  index_max = sizetype->_hi - 1;
1552   const TypeLong* lidxtype = TypeLong::make(CONST64(0), index_max, Type::WidenMax);
1553   idx = _gvn.transform( new (C, 2) ConvI2LNode(idx, lidxtype) );
1554 #endif
1555   Node* scale = _gvn.transform( new (C, 3) LShiftXNode(idx, intcon(shift)) );
1556   return basic_plus_adr(ary, base, scale);
1557 }
1558 
1559 //-------------------------load_array_element-------------------------
1560 Node* GraphKit::load_array_element(Node* ctl, Node* ary, Node* idx, const TypeAryPtr* arytype) {
1561   const Type* elemtype = arytype->elem();
1562   BasicType elembt = elemtype->array_element_basic_type();
1563   Node* adr = array_element_address(ary, idx, elembt, arytype->size());
1564   Node* ld = make_load(ctl, adr, elemtype, elembt, arytype);
1565   return ld;
1566 }
1567 
1568 //-------------------------set_arguments_for_java_call-------------------------
1569 // Arguments (pre-popped from the stack) are taken from the JVMS.
1570 void GraphKit::set_arguments_for_java_call(CallJavaNode* call) {
1571   // Add the call arguments:
1572   uint nargs = call->method()->arg_size();
1573   for (uint i = 0; i < nargs; i++) {
1574     Node* arg = argument(i);
1575     call->init_req(i + TypeFunc::Parms, arg);
1576   }
1577 }
1578 
1579 //---------------------------set_edges_for_java_call---------------------------
1580 // Connect a newly created call into the current JVMS.
1581 // A return value node (if any) is returned from set_edges_for_java_call.
1582 void GraphKit::set_edges_for_java_call(CallJavaNode* call, bool must_throw) {
1583 
1584   // Add the predefined inputs:
1585   call->init_req( TypeFunc::Control, control() );
1586   call->init_req( TypeFunc::I_O    , i_o() );
1587   call->init_req( TypeFunc::Memory , reset_memory() );
1588   call->init_req( TypeFunc::FramePtr, frameptr() );
1589   call->init_req( TypeFunc::ReturnAdr, top() );
1590 
1591   add_safepoint_edges(call, must_throw);
1592 
1593   Node* xcall = _gvn.transform(call);
1594 
1595   if (xcall == top()) {
1596     set_control(top());
1597     return;
1598   }
1599   assert(xcall == call, "call identity is stable");
1600 
1601   // Re-use the current map to produce the result.
1602 
1603   set_control(_gvn.transform(new (C, 1) ProjNode(call, TypeFunc::Control)));
1604   set_i_o(    _gvn.transform(new (C, 1) ProjNode(call, TypeFunc::I_O    )));
1605   set_all_memory_call(xcall);
1606 
1607   //return xcall;   // no need, caller already has it
1608 }
1609 
1610 Node* GraphKit::set_results_for_java_call(CallJavaNode* call) {
1611   if (stopped())  return top();  // maybe the call folded up?
1612 
1613   // Capture the return value, if any.
1614   Node* ret;
1615   if (call->method() == NULL ||
1616       call->method()->return_type()->basic_type() == T_VOID)
1617         ret = top();
1618   else  ret = _gvn.transform(new (C, 1) ProjNode(call, TypeFunc::Parms));
1619 
1620   // Note:  Since any out-of-line call can produce an exception,
1621   // we always insert an I_O projection from the call into the result.
1622 
1623   make_slow_call_ex(call, env()->Throwable_klass(), false);
1624 
1625   return ret;
1626 }
1627 
1628 //--------------------set_predefined_input_for_runtime_call--------------------
1629 // Reading and setting the memory state is way conservative here.
1630 // The real problem is that I am not doing real Type analysis on memory,
1631 // so I cannot distinguish card mark stores from other stores.  Across a GC
1632 // point the Store Barrier and the card mark memory has to agree.  I cannot
1633 // have a card mark store and its barrier split across the GC point from
1634 // either above or below.  Here I get that to happen by reading ALL of memory.
1635 // A better answer would be to separate out card marks from other memory.
1636 // For now, return the input memory state, so that it can be reused
1637 // after the call, if this call has restricted memory effects.
1638 Node* GraphKit::set_predefined_input_for_runtime_call(SafePointNode* call) {
1639   // Set fixed predefined input arguments
1640   Node* memory = reset_memory();
1641   call->init_req( TypeFunc::Control,   control()  );
1642   call->init_req( TypeFunc::I_O,       top()      ); // does no i/o
1643   call->init_req( TypeFunc::Memory,    memory     ); // may gc ptrs
1644   call->init_req( TypeFunc::FramePtr,  frameptr() );
1645   call->init_req( TypeFunc::ReturnAdr, top()      );
1646   return memory;
1647 }
1648 
1649 //-------------------set_predefined_output_for_runtime_call--------------------
1650 // Set control and memory (not i_o) from the call.
1651 // If keep_mem is not NULL, use it for the output state,
1652 // except for the RawPtr output of the call, if hook_mem is TypeRawPtr::BOTTOM.
1653 // If hook_mem is NULL, this call produces no memory effects at all.
1654 // If hook_mem is a Java-visible memory slice (such as arraycopy operands),
1655 // then only that memory slice is taken from the call.
1656 // In the last case, we must put an appropriate memory barrier before
1657 // the call, so as to create the correct anti-dependencies on loads
1658 // preceding the call.
1659 void GraphKit::set_predefined_output_for_runtime_call(Node* call,
1660                                                       Node* keep_mem,
1661                                                       const TypePtr* hook_mem) {
1662   // no i/o
1663   set_control(_gvn.transform( new (C, 1) ProjNode(call,TypeFunc::Control) ));
1664   if (keep_mem) {
1665     // First clone the existing memory state
1666     set_all_memory(keep_mem);
1667     if (hook_mem != NULL) {
1668       // Make memory for the call
1669       Node* mem = _gvn.transform( new (C, 1) ProjNode(call, TypeFunc::Memory) );
1670       // Set the RawPtr memory state only.  This covers all the heap top/GC stuff
1671       // We also use hook_mem to extract specific effects from arraycopy stubs.
1672       set_memory(mem, hook_mem);
1673     }
1674     // ...else the call has NO memory effects.
1675 
1676     // Make sure the call advertises its memory effects precisely.
1677     // This lets us build accurate anti-dependences in gcm.cpp.
1678     assert(C->alias_type(call->adr_type()) == C->alias_type(hook_mem),
1679            "call node must be constructed correctly");
1680   } else {
1681     assert(hook_mem == NULL, "");
1682     // This is not a "slow path" call; all memory comes from the call.
1683     set_all_memory_call(call);
1684   }
1685 }
1686 
1687 //------------------------------increment_counter------------------------------
1688 // for statistics: increment a VM counter by 1
1689 
1690 void GraphKit::increment_counter(address counter_addr) {
1691   Node* adr1 = makecon(TypeRawPtr::make(counter_addr));
1692   increment_counter(adr1);
1693 }
1694 
1695 void GraphKit::increment_counter(Node* counter_addr) {
1696   int adr_type = Compile::AliasIdxRaw;
1697   Node* cnt  = make_load(NULL, counter_addr, TypeInt::INT, T_INT, adr_type);
1698   Node* incr = _gvn.transform(new (C, 3) AddINode(cnt, _gvn.intcon(1)));
1699   store_to_memory( NULL, counter_addr, incr, T_INT, adr_type );
1700 }
1701 
1702 
1703 //------------------------------uncommon_trap----------------------------------
1704 // Bail out to the interpreter in mid-method.  Implemented by calling the
1705 // uncommon_trap blob.  This helper function inserts a runtime call with the
1706 // right debug info.
1707 void GraphKit::uncommon_trap(int trap_request,
1708                              ciKlass* klass, const char* comment,
1709                              bool must_throw,
1710                              bool keep_exact_action) {
1711   if (failing())  stop();
1712   if (stopped())  return; // trap reachable?
1713 
1714   // Note:  If ProfileTraps is true, and if a deopt. actually
1715   // occurs here, the runtime will make sure an MDO exists.  There is
1716   // no need to call method()->build_method_data() at this point.
1717 
1718 #ifdef ASSERT
1719   if (!must_throw) {
1720     // Make sure the stack has at least enough depth to execute
1721     // the current bytecode.
1722     int inputs, ignore;
1723     if (compute_stack_effects(inputs, ignore)) {
1724       assert(sp() >= inputs, "must have enough JVMS stack to execute");
1725       // It is a frequent error in library_call.cpp to issue an
1726       // uncommon trap with the _sp value already popped.
1727     }
1728   }
1729 #endif
1730 
1731   Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(trap_request);
1732   Deoptimization::DeoptAction action = Deoptimization::trap_request_action(trap_request);
1733 
1734   switch (action) {
1735   case Deoptimization::Action_maybe_recompile:
1736   case Deoptimization::Action_reinterpret:
1737     // Temporary fix for 6529811 to allow virtual calls to be sure they
1738     // get the chance to go from mono->bi->mega
1739     if (!keep_exact_action &&
1740         Deoptimization::trap_request_index(trap_request) < 0 &&
1741         too_many_recompiles(reason)) {
1742       // This BCI is causing too many recompilations.
1743       action = Deoptimization::Action_none;
1744       trap_request = Deoptimization::make_trap_request(reason, action);
1745     } else {
1746       C->set_trap_can_recompile(true);
1747     }
1748     break;
1749   case Deoptimization::Action_make_not_entrant:
1750     C->set_trap_can_recompile(true);
1751     break;
1752 #ifdef ASSERT
1753   case Deoptimization::Action_none:
1754   case Deoptimization::Action_make_not_compilable:
1755     break;
1756   default:
1757     assert(false, "bad action");
1758 #endif
1759   }
1760 
1761   if (TraceOptoParse) {
1762     char buf[100];
1763     tty->print_cr("Uncommon trap %s at bci:%d",
1764                   Deoptimization::format_trap_request(buf, sizeof(buf),
1765                                                       trap_request), bci());
1766   }
1767 
1768   CompileLog* log = C->log();
1769   if (log != NULL) {
1770     int kid = (klass == NULL)? -1: log->identify(klass);
1771     log->begin_elem("uncommon_trap bci='%d'", bci());
1772     char buf[100];
1773     log->print(" %s", Deoptimization::format_trap_request(buf, sizeof(buf),
1774                                                           trap_request));
1775     if (kid >= 0)         log->print(" klass='%d'", kid);
1776     if (comment != NULL)  log->print(" comment='%s'", comment);
1777     log->end_elem();
1778   }
1779 
1780   // Make sure any guarding test views this path as very unlikely
1781   Node *i0 = control()->in(0);
1782   if (i0 != NULL && i0->is_If()) {        // Found a guarding if test?
1783     IfNode *iff = i0->as_If();
1784     float f = iff->_prob;   // Get prob
1785     if (control()->Opcode() == Op_IfTrue) {
1786       if (f > PROB_UNLIKELY_MAG(4))
1787         iff->_prob = PROB_MIN;
1788     } else {
1789       if (f < PROB_LIKELY_MAG(4))
1790         iff->_prob = PROB_MAX;
1791     }
1792   }
1793 
1794   // Clear out dead values from the debug info.
1795   kill_dead_locals();
1796 
1797   // Now insert the uncommon trap subroutine call
1798   address call_addr = SharedRuntime::uncommon_trap_blob()->instructions_begin();
1799   const TypePtr* no_memory_effects = NULL;
1800   // Pass the index of the class to be loaded
1801   Node* call = make_runtime_call(RC_NO_LEAF | RC_UNCOMMON |
1802                                  (must_throw ? RC_MUST_THROW : 0),
1803                                  OptoRuntime::uncommon_trap_Type(),
1804                                  call_addr, "uncommon_trap", no_memory_effects,
1805                                  intcon(trap_request));
1806   assert(call->as_CallStaticJava()->uncommon_trap_request() == trap_request,
1807          "must extract request correctly from the graph");
1808   assert(trap_request != 0, "zero value reserved by uncommon_trap_request");
1809 
1810   call->set_req(TypeFunc::ReturnAdr, returnadr());
1811   // The debug info is the only real input to this call.
1812 
1813   // Halt-and-catch fire here.  The above call should never return!
1814   HaltNode* halt = new(C, TypeFunc::Parms) HaltNode(control(), frameptr());
1815   _gvn.set_type_bottom(halt);
1816   root()->add_req(halt);
1817 
1818   stop_and_kill_map();
1819 }
1820 
1821 
1822 //--------------------------just_allocated_object------------------------------
1823 // Report the object that was just allocated.
1824 // It must be the case that there are no intervening safepoints.
1825 // We use this to determine if an object is so "fresh" that
1826 // it does not require card marks.
1827 Node* GraphKit::just_allocated_object(Node* current_control) {
1828   if (C->recent_alloc_ctl() == current_control)
1829     return C->recent_alloc_obj();
1830   return NULL;
1831 }
1832 
1833 
1834 //------------------------------store_barrier----------------------------------
1835 // Insert a write-barrier store.  This is to let generational GC work; we have
1836 // to flag all oop-stores before the next GC point.
1837 void GraphKit::write_barrier_post(Node* oop_store, Node* obj, Node* adr,
1838                                   Node* val, bool use_precise) {
1839   // No store check needed if we're storing a NULL or an old object
1840   // (latter case is probably a string constant). The concurrent
1841   // mark sweep garbage collector, however, needs to have all nonNull
1842   // oop updates flagged via card-marks.
1843   if (val != NULL && val->is_Con()) {
1844     // must be either an oop or NULL
1845     const Type* t = val->bottom_type();
1846     if (t == TypePtr::NULL_PTR || t == Type::TOP)
1847       // stores of null never (?) need barriers
1848       return;
1849     ciObject* con = t->is_oopptr()->const_oop();
1850     if (con != NULL
1851         && con->is_perm()
1852         && Universe::heap()->can_elide_permanent_oop_store_barriers())
1853       // no store barrier needed, because no old-to-new ref created
1854       return;
1855   }
1856 
1857   if (use_ReduceInitialCardMarks()
1858       && obj == just_allocated_object(control())) {
1859     // We can skip marks on a freshly-allocated object.
1860     // Keep this code in sync with do_eager_card_mark in runtime.cpp.
1861     // That routine eagerly marks the occasional object which is produced
1862     // by the slow path, so that we don't have to do it here.
1863     return;
1864   }
1865 
1866   if (!use_precise) {
1867     // All card marks for a (non-array) instance are in one place:
1868     adr = obj;
1869   }
1870   // (Else it's an array (or unknown), and we want more precise card marks.)
1871   assert(adr != NULL, "");
1872 
1873   // Get the alias_index for raw card-mark memory
1874   int adr_type = Compile::AliasIdxRaw;
1875   // Convert the pointer to an int prior to doing math on it
1876   Node* cast = _gvn.transform(new (C, 2) CastP2XNode(control(), adr));
1877   // Divide by card size
1878   assert(Universe::heap()->barrier_set()->kind() == BarrierSet::CardTableModRef,
1879          "Only one we handle so far.");
1880   CardTableModRefBS* ct =
1881     (CardTableModRefBS*)(Universe::heap()->barrier_set());
1882   Node *b = _gvn.transform(new (C, 3) URShiftXNode( cast, _gvn.intcon(CardTableModRefBS::card_shift) ));
1883   // We store into a byte array, so do not bother to left-shift by zero
1884   Node *c = byte_map_base_node();
1885   // Combine
1886   Node *sb_ctl = control();
1887   Node *sb_adr = _gvn.transform(new (C, 4) AddPNode( top()/*no base ptr*/, c, b ));
1888   Node *sb_val = _gvn.intcon(0);
1889   // Smash zero into card
1890   if( !UseConcMarkSweepGC ) {
1891     BasicType bt = T_BYTE;
1892     store_to_memory(sb_ctl, sb_adr, sb_val, bt, adr_type);
1893   } else {
1894     // Specialized path for CM store barrier
1895     cms_card_mark( sb_ctl, sb_adr, sb_val, oop_store);
1896   }
1897 }
1898 
1899 // Specialized path for CMS store barrier
1900 void GraphKit::cms_card_mark(Node* ctl, Node* adr, Node* val, Node *oop_store) {
1901   BasicType bt = T_BYTE;
1902   int adr_idx = Compile::AliasIdxRaw;
1903   Node* mem = memory(adr_idx);
1904 
1905   // The type input is NULL in PRODUCT builds
1906   const TypePtr* type = NULL;
1907   debug_only(type = C->get_adr_type(adr_idx));
1908 
1909   // Add required edge to oop_store, optimizer does not support precedence edges.
1910   // Convert required edge to precedence edge before allocation.
1911   Node *store = _gvn.transform( new (C, 5) StoreCMNode(ctl, mem, adr, type, val, oop_store) );
1912   set_memory(store, adr_idx);
1913 
1914   // For CMS, back-to-back card-marks can only remove the first one
1915   // and this requires DU info.  Push on worklist for optimizer.
1916   if (mem->req() > MemNode::Address && adr == mem->in(MemNode::Address))
1917     record_for_igvn(store);
1918 }
1919 
1920 
1921 void GraphKit::round_double_arguments(ciMethod* dest_method) {
1922   // (Note:  TypeFunc::make has a cache that makes this fast.)
1923   const TypeFunc* tf    = TypeFunc::make(dest_method);
1924   int             nargs = tf->_domain->_cnt - TypeFunc::Parms;
1925   for (int j = 0; j < nargs; j++) {
1926     const Type *targ = tf->_domain->field_at(j + TypeFunc::Parms);
1927     if( targ->basic_type() == T_DOUBLE ) {
1928       // If any parameters are doubles, they must be rounded before
1929       // the call, dstore_rounding does gvn.transform
1930       Node *arg = argument(j);
1931       arg = dstore_rounding(arg);
1932       set_argument(j, arg);
1933     }
1934   }
1935 }
1936 
1937 void GraphKit::round_double_result(ciMethod* dest_method) {
1938   // A non-strict method may return a double value which has an extended
1939   // exponent, but this must not be visible in a caller which is 'strict'
1940   // If a strict caller invokes a non-strict callee, round a double result
1941 
1942   BasicType result_type = dest_method->return_type()->basic_type();
1943   assert( method() != NULL, "must have caller context");
1944   if( result_type == T_DOUBLE && method()->is_strict() && !dest_method->is_strict() ) {
1945     // Destination method's return value is on top of stack
1946     // dstore_rounding() does gvn.transform
1947     Node *result = pop_pair();
1948     result = dstore_rounding(result);
1949     push_pair(result);
1950   }
1951 }
1952 
1953 // rounding for strict float precision conformance
1954 Node* GraphKit::precision_rounding(Node* n) {
1955   return UseStrictFP && _method->flags().is_strict()
1956     && UseSSE == 0 && Matcher::strict_fp_requires_explicit_rounding
1957     ? _gvn.transform( new (C, 2) RoundFloatNode(0, n) )
1958     : n;
1959 }
1960 
1961 // rounding for strict double precision conformance
1962 Node* GraphKit::dprecision_rounding(Node *n) {
1963   return UseStrictFP && _method->flags().is_strict()
1964     && UseSSE <= 1 && Matcher::strict_fp_requires_explicit_rounding
1965     ? _gvn.transform( new (C, 2) RoundDoubleNode(0, n) )
1966     : n;
1967 }
1968 
1969 // rounding for non-strict double stores
1970 Node* GraphKit::dstore_rounding(Node* n) {
1971   return Matcher::strict_fp_requires_explicit_rounding
1972     && UseSSE <= 1
1973     ? _gvn.transform( new (C, 2) RoundDoubleNode(0, n) )
1974     : n;
1975 }
1976 
1977 //=============================================================================
1978 // Generate a fast path/slow path idiom.  Graph looks like:
1979 // [foo] indicates that 'foo' is a parameter
1980 //
1981 //              [in]     NULL
1982 //                 \    /
1983 //                  CmpP
1984 //                  Bool ne
1985 //                   If
1986 //                  /  \
1987 //              True    False-<2>
1988 //              / |
1989 //             /  cast_not_null
1990 //           Load  |    |   ^
1991 //        [fast_test]   |   |
1992 // gvn to   opt_test    |   |
1993 //          /    \      |  <1>
1994 //      True     False  |
1995 //        |         \\  |
1996 //   [slow_call]     \[fast_result]
1997 //    Ctl   Val       \      \
1998 //     |               \      \
1999 //    Catch       <1>   \      \
2000 //   /    \        ^     \      \
2001 //  Ex    No_Ex    |      \      \
2002 //  |       \   \  |       \ <2>  \
2003 //  ...      \  [slow_res] |  |    \   [null_result]
2004 //            \         \--+--+---  |  |
2005 //             \           | /    \ | /
2006 //              --------Region     Phi
2007 //
2008 //=============================================================================
2009 // Code is structured as a series of driver functions all called 'do_XXX' that
2010 // call a set of helper functions.  Helper functions first, then drivers.
2011 
2012 //------------------------------null_check_oop---------------------------------
2013 // Null check oop.  Set null-path control into Region in slot 3.
2014 // Make a cast-not-nullness use the other not-null control.  Return cast.
2015 Node* GraphKit::null_check_oop(Node* value, Node* *null_control,
2016                                bool never_see_null) {
2017   // Initial NULL check taken path
2018   (*null_control) = top();
2019   Node* cast = null_check_common(value, T_OBJECT, false, null_control);
2020 
2021   // Generate uncommon_trap:
2022   if (never_see_null && (*null_control) != top()) {
2023     // If we see an unexpected null at a check-cast we record it and force a
2024     // recompile; the offending check-cast will be compiled to handle NULLs.
2025     // If we see more than one offending BCI, then all checkcasts in the
2026     // method will be compiled to handle NULLs.
2027     PreserveJVMState pjvms(this);
2028     set_control(*null_control);
2029     replace_in_map(value, null());
2030     uncommon_trap(Deoptimization::Reason_null_check,
2031                   Deoptimization::Action_make_not_entrant);
2032     (*null_control) = top();    // NULL path is dead
2033   }
2034 
2035   // Cast away null-ness on the result
2036   return cast;
2037 }
2038 
2039 //------------------------------opt_iff----------------------------------------
2040 // Optimize the fast-check IfNode.  Set the fast-path region slot 2.
2041 // Return slow-path control.
2042 Node* GraphKit::opt_iff(Node* region, Node* iff) {
2043   IfNode *opt_iff = _gvn.transform(iff)->as_If();
2044 
2045   // Fast path taken; set region slot 2
2046   Node *fast_taken = _gvn.transform( new (C, 1) IfFalseNode(opt_iff) );
2047   region->init_req(2,fast_taken); // Capture fast-control
2048 
2049   // Fast path not-taken, i.e. slow path
2050   Node *slow_taken = _gvn.transform( new (C, 1) IfTrueNode(opt_iff) );
2051   return slow_taken;
2052 }
2053 
2054 //-----------------------------make_runtime_call-------------------------------
2055 Node* GraphKit::make_runtime_call(int flags,
2056                                   const TypeFunc* call_type, address call_addr,
2057                                   const char* call_name,
2058                                   const TypePtr* adr_type,
2059                                   // The following parms are all optional.
2060                                   // The first NULL ends the list.
2061                                   Node* parm0, Node* parm1,
2062                                   Node* parm2, Node* parm3,
2063                                   Node* parm4, Node* parm5,
2064                                   Node* parm6, Node* parm7) {
2065   // Slow-path call
2066   int size = call_type->domain()->cnt();
2067   bool is_leaf = !(flags & RC_NO_LEAF);
2068   bool has_io  = (!is_leaf && !(flags & RC_NO_IO));
2069   if (call_name == NULL) {
2070     assert(!is_leaf, "must supply name for leaf");
2071     call_name = OptoRuntime::stub_name(call_addr);
2072   }
2073   CallNode* call;
2074   if (!is_leaf) {
2075     call = new(C, size) CallStaticJavaNode(call_type, call_addr, call_name,
2076                                            bci(), adr_type);
2077   } else if (flags & RC_NO_FP) {
2078     call = new(C, size) CallLeafNoFPNode(call_type, call_addr, call_name, adr_type);
2079   } else {
2080     call = new(C, size) CallLeafNode(call_type, call_addr, call_name, adr_type);
2081   }
2082 
2083   // The following is similar to set_edges_for_java_call,
2084   // except that the memory effects of the call are restricted to AliasIdxRaw.
2085 
2086   // Slow path call has no side-effects, uses few values
2087   bool wide_in  = !(flags & RC_NARROW_MEM);
2088   bool wide_out = (C->get_alias_index(adr_type) == Compile::AliasIdxBot);
2089 
2090   Node* prev_mem = NULL;
2091   if (wide_in) {
2092     prev_mem = set_predefined_input_for_runtime_call(call);
2093   } else {
2094     assert(!wide_out, "narrow in => narrow out");
2095     Node* narrow_mem = memory(adr_type);
2096     prev_mem = reset_memory();
2097     map()->set_memory(narrow_mem);
2098     set_predefined_input_for_runtime_call(call);
2099   }
2100 
2101   // Hook each parm in order.  Stop looking at the first NULL.
2102   if (parm0 != NULL) { call->init_req(TypeFunc::Parms+0, parm0);
2103   if (parm1 != NULL) { call->init_req(TypeFunc::Parms+1, parm1);
2104   if (parm2 != NULL) { call->init_req(TypeFunc::Parms+2, parm2);
2105   if (parm3 != NULL) { call->init_req(TypeFunc::Parms+3, parm3);
2106   if (parm4 != NULL) { call->init_req(TypeFunc::Parms+4, parm4);
2107   if (parm5 != NULL) { call->init_req(TypeFunc::Parms+5, parm5);
2108   if (parm6 != NULL) { call->init_req(TypeFunc::Parms+6, parm6);
2109   if (parm7 != NULL) { call->init_req(TypeFunc::Parms+7, parm7);
2110     /* close each nested if ===> */  } } } } } } } }
2111   assert(call->in(call->req()-1) != NULL, "must initialize all parms");
2112 
2113   if (!is_leaf) {
2114     // Non-leaves can block and take safepoints:
2115     add_safepoint_edges(call, ((flags & RC_MUST_THROW) != 0));
2116   }
2117   // Non-leaves can throw exceptions:
2118   if (has_io) {
2119     call->set_req(TypeFunc::I_O, i_o());
2120   }
2121 
2122   if (flags & RC_UNCOMMON) {
2123     // Set the count to a tiny probability.  Cf. Estimate_Block_Frequency.
2124     // (An "if" probability corresponds roughly to an unconditional count.
2125     // Sort of.)
2126     call->set_cnt(PROB_UNLIKELY_MAG(4));
2127   }
2128 
2129   Node* c = _gvn.transform(call);
2130   assert(c == call, "cannot disappear");
2131 
2132   if (wide_out) {
2133     // Slow path call has full side-effects.
2134     set_predefined_output_for_runtime_call(call);
2135   } else {
2136     // Slow path call has few side-effects, and/or sets few values.
2137     set_predefined_output_for_runtime_call(call, prev_mem, adr_type);
2138   }
2139 
2140   if (has_io) {
2141     set_i_o(_gvn.transform(new (C, 1) ProjNode(call, TypeFunc::I_O)));
2142   }
2143   return call;
2144 
2145 }
2146 
2147 //------------------------------merge_memory-----------------------------------
2148 // Merge memory from one path into the current memory state.
2149 void GraphKit::merge_memory(Node* new_mem, Node* region, int new_path) {
2150   for (MergeMemStream mms(merged_memory(), new_mem->as_MergeMem()); mms.next_non_empty2(); ) {
2151     Node* old_slice = mms.force_memory();
2152     Node* new_slice = mms.memory2();
2153     if (old_slice != new_slice) {
2154       PhiNode* phi;
2155       if (new_slice->is_Phi() && new_slice->as_Phi()->region() == region) {
2156         phi = new_slice->as_Phi();
2157         #ifdef ASSERT
2158         if (old_slice->is_Phi() && old_slice->as_Phi()->region() == region)
2159           old_slice = old_slice->in(new_path);
2160         // Caller is responsible for ensuring that any pre-existing
2161         // phis are already aware of old memory.
2162         int old_path = (new_path > 1) ? 1 : 2;  // choose old_path != new_path
2163         assert(phi->in(old_path) == old_slice, "pre-existing phis OK");
2164         #endif
2165         mms.set_memory(phi);
2166       } else {
2167         phi = PhiNode::make(region, old_slice, Type::MEMORY, mms.adr_type(C));
2168         _gvn.set_type(phi, Type::MEMORY);
2169         phi->set_req(new_path, new_slice);
2170         mms.set_memory(_gvn.transform(phi));  // assume it is complete
2171       }
2172     }
2173   }
2174 }
2175 
2176 //------------------------------make_slow_call_ex------------------------------
2177 // Make the exception handler hookups for the slow call
2178 void GraphKit::make_slow_call_ex(Node* call, ciInstanceKlass* ex_klass, bool separate_io_proj) {
2179   if (stopped())  return;
2180 
2181   // Make a catch node with just two handlers:  fall-through and catch-all
2182   Node* i_o  = _gvn.transform( new (C, 1) ProjNode(call, TypeFunc::I_O, separate_io_proj) );
2183   Node* catc = _gvn.transform( new (C, 2) CatchNode(control(), i_o, 2) );
2184   Node* norm = _gvn.transform( new (C, 1) CatchProjNode(catc, CatchProjNode::fall_through_index, CatchProjNode::no_handler_bci) );
2185   Node* excp = _gvn.transform( new (C, 1) CatchProjNode(catc, CatchProjNode::catch_all_index,    CatchProjNode::no_handler_bci) );
2186 
2187   { PreserveJVMState pjvms(this);
2188     set_control(excp);
2189     set_i_o(i_o);
2190 
2191     if (excp != top()) {
2192       // Create an exception state also.
2193       // Use an exact type if the caller has specified a specific exception.
2194       const Type* ex_type = TypeOopPtr::make_from_klass_unique(ex_klass)->cast_to_ptr_type(TypePtr::NotNull);
2195       Node*       ex_oop  = new (C, 2) CreateExNode(ex_type, control(), i_o);
2196       add_exception_state(make_exception_state(_gvn.transform(ex_oop)));
2197     }
2198   }
2199 
2200   // Get the no-exception control from the CatchNode.
2201   set_control(norm);
2202 }
2203 
2204 
2205 //-------------------------------gen_subtype_check-----------------------------
2206 // Generate a subtyping check.  Takes as input the subtype and supertype.
2207 // Returns 2 values: sets the default control() to the true path and returns
2208 // the false path.  Only reads invariant memory; sets no (visible) memory.
2209 // The PartialSubtypeCheckNode sets the hidden 1-word cache in the encoding
2210 // but that's not exposed to the optimizer.  This call also doesn't take in an
2211 // Object; if you wish to check an Object you need to load the Object's class
2212 // prior to coming here.
2213 Node* GraphKit::gen_subtype_check(Node* subklass, Node* superklass) {
2214   // Fast check for identical types, perhaps identical constants.
2215   // The types can even be identical non-constants, in cases
2216   // involving Array.newInstance, Object.clone, etc.
2217   if (subklass == superklass)
2218     return top();             // false path is dead; no test needed.
2219 
2220   if (_gvn.type(superklass)->singleton()) {
2221     ciKlass* superk = _gvn.type(superklass)->is_klassptr()->klass();
2222     ciKlass* subk   = _gvn.type(subklass)->is_klassptr()->klass();
2223 
2224     // In the common case of an exact superklass, try to fold up the
2225     // test before generating code.  You may ask, why not just generate
2226     // the code and then let it fold up?  The answer is that the generated
2227     // code will necessarily include null checks, which do not always
2228     // completely fold away.  If they are also needless, then they turn
2229     // into a performance loss.  Example:
2230     //    Foo[] fa = blah(); Foo x = fa[0]; fa[1] = x;
2231     // Here, the type of 'fa' is often exact, so the store check
2232     // of fa[1]=x will fold up, without testing the nullness of x.
2233     switch (static_subtype_check(superk, subk)) {
2234     case SSC_always_false:
2235       {
2236         Node* always_fail = control();
2237         set_control(top());
2238         return always_fail;
2239       }
2240     case SSC_always_true:
2241       return top();
2242     case SSC_easy_test:
2243       {
2244         // Just do a direct pointer compare and be done.
2245         Node* cmp = _gvn.transform( new(C, 3) CmpPNode(subklass, superklass) );
2246         Node* bol = _gvn.transform( new(C, 2) BoolNode(cmp, BoolTest::eq) );
2247         IfNode* iff = create_and_xform_if(control(), bol, PROB_STATIC_FREQUENT, COUNT_UNKNOWN);
2248         set_control( _gvn.transform( new(C, 1) IfTrueNode (iff) ) );
2249         return       _gvn.transform( new(C, 1) IfFalseNode(iff) );
2250       }
2251     case SSC_full_test:
2252       break;
2253     default:
2254       ShouldNotReachHere();
2255     }
2256   }
2257 
2258   // %%% Possible further optimization:  Even if the superklass is not exact,
2259   // if the subklass is the unique subtype of the superklass, the check
2260   // will always succeed.  We could leave a dependency behind to ensure this.
2261 
2262   // First load the super-klass's check-offset
2263   Node *p1 = basic_plus_adr( superklass, superklass, sizeof(oopDesc) + Klass::super_check_offset_offset_in_bytes() );
2264   Node *chk_off = _gvn.transform( new (C, 3) LoadINode( NULL, memory(p1), p1, _gvn.type(p1)->is_ptr() ) );
2265   int cacheoff_con = sizeof(oopDesc) + Klass::secondary_super_cache_offset_in_bytes();
2266   bool might_be_cache = (find_int_con(chk_off, cacheoff_con) == cacheoff_con);
2267 
2268   // Load from the sub-klass's super-class display list, or a 1-word cache of
2269   // the secondary superclass list, or a failing value with a sentinel offset
2270   // if the super-klass is an interface or exceptionally deep in the Java
2271   // hierarchy and we have to scan the secondary superclass list the hard way.
2272   // Worst-case type is a little odd: NULL is allowed as a result (usually
2273   // klass loads can never produce a NULL).
2274   Node *chk_off_X = ConvI2X(chk_off);
2275   Node *p2 = _gvn.transform( new (C, 4) AddPNode(subklass,subklass,chk_off_X) );
2276   // For some types like interfaces the following loadKlass is from a 1-word
2277   // cache which is mutable so can't use immutable memory.  Other
2278   // types load from the super-class display table which is immutable.
2279   Node *kmem = might_be_cache ? memory(p2) : immutable_memory();
2280   Node *nkls = _gvn.transform( LoadKlassNode::make( _gvn, kmem, p2, _gvn.type(p2)->is_ptr(), TypeKlassPtr::OBJECT_OR_NULL ) );
2281 
2282   // Compile speed common case: ARE a subtype and we canNOT fail
2283   if( superklass == nkls )
2284     return top();             // false path is dead; no test needed.
2285 
2286   // See if we get an immediate positive hit.  Happens roughly 83% of the
2287   // time.  Test to see if the value loaded just previously from the subklass
2288   // is exactly the superklass.
2289   Node *cmp1 = _gvn.transform( new (C, 3) CmpPNode( superklass, nkls ) );
2290   Node *bol1 = _gvn.transform( new (C, 2) BoolNode( cmp1, BoolTest::eq ) );
2291   IfNode *iff1 = create_and_xform_if( control(), bol1, PROB_LIKELY(0.83f), COUNT_UNKNOWN );
2292   Node *iftrue1 = _gvn.transform( new (C, 1) IfTrueNode ( iff1 ) );
2293   set_control(    _gvn.transform( new (C, 1) IfFalseNode( iff1 ) ) );
2294 
2295   // Compile speed common case: Check for being deterministic right now.  If
2296   // chk_off is a constant and not equal to cacheoff then we are NOT a
2297   // subklass.  In this case we need exactly the 1 test above and we can
2298   // return those results immediately.
2299   if (!might_be_cache) {
2300     Node* not_subtype_ctrl = control();
2301     set_control(iftrue1); // We need exactly the 1 test above
2302     return not_subtype_ctrl;
2303   }
2304 
2305   // Gather the various success & failures here
2306   RegionNode *r_ok_subtype = new (C, 4) RegionNode(4);
2307   record_for_igvn(r_ok_subtype);
2308   RegionNode *r_not_subtype = new (C, 3) RegionNode(3);
2309   record_for_igvn(r_not_subtype);
2310 
2311   r_ok_subtype->init_req(1, iftrue1);
2312 
2313   // Check for immediate negative hit.  Happens roughly 11% of the time (which
2314   // is roughly 63% of the remaining cases).  Test to see if the loaded
2315   // check-offset points into the subklass display list or the 1-element
2316   // cache.  If it points to the display (and NOT the cache) and the display
2317   // missed then it's not a subtype.
2318   Node *cacheoff = _gvn.intcon(cacheoff_con);
2319   Node *cmp2 = _gvn.transform( new (C, 3) CmpINode( chk_off, cacheoff ) );
2320   Node *bol2 = _gvn.transform( new (C, 2) BoolNode( cmp2, BoolTest::ne ) );
2321   IfNode *iff2 = create_and_xform_if( control(), bol2, PROB_LIKELY(0.63f), COUNT_UNKNOWN );
2322   r_not_subtype->init_req(1, _gvn.transform( new (C, 1) IfTrueNode (iff2) ) );
2323   set_control(                _gvn.transform( new (C, 1) IfFalseNode(iff2) ) );
2324 
2325   // Check for self.  Very rare to get here, but it is taken 1/3 the time.
2326   // No performance impact (too rare) but allows sharing of secondary arrays
2327   // which has some footprint reduction.
2328   Node *cmp3 = _gvn.transform( new (C, 3) CmpPNode( subklass, superklass ) );
2329   Node *bol3 = _gvn.transform( new (C, 2) BoolNode( cmp3, BoolTest::eq ) );
2330   IfNode *iff3 = create_and_xform_if( control(), bol3, PROB_LIKELY(0.36f), COUNT_UNKNOWN );
2331   r_ok_subtype->init_req(2, _gvn.transform( new (C, 1) IfTrueNode ( iff3 ) ) );
2332   set_control(               _gvn.transform( new (C, 1) IfFalseNode( iff3 ) ) );
2333 
2334   // -- Roads not taken here: --
2335   // We could also have chosen to perform the self-check at the beginning
2336   // of this code sequence, as the assembler does.  This would not pay off
2337   // the same way, since the optimizer, unlike the assembler, can perform
2338   // static type analysis to fold away many successful self-checks.
2339   // Non-foldable self checks work better here in second position, because
2340   // the initial primary superclass check subsumes a self-check for most
2341   // types.  An exception would be a secondary type like array-of-interface,
2342   // which does not appear in its own primary supertype display.
2343   // Finally, we could have chosen to move the self-check into the
2344   // PartialSubtypeCheckNode, and from there out-of-line in a platform
2345   // dependent manner.  But it is worthwhile to have the check here,
2346   // where it can be perhaps be optimized.  The cost in code space is
2347   // small (register compare, branch).
2348 
2349   // Now do a linear scan of the secondary super-klass array.  Again, no real
2350   // performance impact (too rare) but it's gotta be done.
2351   // Since the code is rarely used, there is no penalty for moving it
2352   // out of line, and it can only improve I-cache density.
2353   // The decision to inline or out-of-line this final check is platform
2354   // dependent, and is found in the AD file definition of PartialSubtypeCheck.
2355   Node* psc = _gvn.transform(
2356     new (C, 3) PartialSubtypeCheckNode(control(), subklass, superklass) );
2357 
2358   Node *cmp4 = _gvn.transform( new (C, 3) CmpPNode( psc, null() ) );
2359   Node *bol4 = _gvn.transform( new (C, 2) BoolNode( cmp4, BoolTest::ne ) );
2360   IfNode *iff4 = create_and_xform_if( control(), bol4, PROB_FAIR, COUNT_UNKNOWN );
2361   r_not_subtype->init_req(2, _gvn.transform( new (C, 1) IfTrueNode (iff4) ) );
2362   r_ok_subtype ->init_req(3, _gvn.transform( new (C, 1) IfFalseNode(iff4) ) );
2363 
2364   // Return false path; set default control to true path.
2365   set_control( _gvn.transform(r_ok_subtype) );
2366   return _gvn.transform(r_not_subtype);
2367 }
2368 
2369 //----------------------------static_subtype_check-----------------------------
2370 // Shortcut important common cases when superklass is exact:
2371 // (0) superklass is java.lang.Object (can occur in reflective code)
2372 // (1) subklass is already limited to a subtype of superklass => always ok
2373 // (2) subklass does not overlap with superklass => always fail
2374 // (3) superklass has NO subtypes and we can check with a simple compare.
2375 int GraphKit::static_subtype_check(ciKlass* superk, ciKlass* subk) {
2376   if (StressReflectiveCode) {
2377     return SSC_full_test;       // Let caller generate the general case.
2378   }
2379 
2380   if (superk == env()->Object_klass()) {
2381     return SSC_always_true;     // (0) this test cannot fail
2382   }
2383 
2384   ciType* superelem = superk;
2385   if (superelem->is_array_klass())
2386     superelem = superelem->as_array_klass()->base_element_type();
2387 
2388   if (!subk->is_interface()) {  // cannot trust static interface types yet
2389     if (subk->is_subtype_of(superk)) {
2390       return SSC_always_true;   // (1) false path dead; no dynamic test needed
2391     }
2392     if (!(superelem->is_klass() && superelem->as_klass()->is_interface()) &&
2393         !superk->is_subtype_of(subk)) {
2394       return SSC_always_false;
2395     }
2396   }
2397 
2398   // If casting to an instance klass, it must have no subtypes
2399   if (superk->is_interface()) {
2400     // Cannot trust interfaces yet.
2401     // %%% S.B. superk->nof_implementors() == 1
2402   } else if (superelem->is_instance_klass()) {
2403     ciInstanceKlass* ik = superelem->as_instance_klass();
2404     if (!ik->has_subklass() && !ik->is_interface()) {
2405       if (!ik->is_final()) {
2406         // Add a dependency if there is a chance of a later subclass.
2407         C->dependencies()->assert_leaf_type(ik);
2408       }
2409       return SSC_easy_test;     // (3) caller can do a simple ptr comparison
2410     }
2411   } else {
2412     // A primitive array type has no subtypes.
2413     return SSC_easy_test;       // (3) caller can do a simple ptr comparison
2414   }
2415 
2416   return SSC_full_test;
2417 }
2418 
2419 // Profile-driven exact type check:
2420 Node* GraphKit::type_check_receiver(Node* receiver, ciKlass* klass,
2421                                     float prob,
2422                                     Node* *casted_receiver) {
2423   const TypeKlassPtr* tklass = TypeKlassPtr::make(klass);
2424   Node* recv_klass = load_object_klass(receiver);
2425   Node* want_klass = makecon(tklass);
2426   Node* cmp = _gvn.transform( new(C, 3) CmpPNode(recv_klass, want_klass) );
2427   Node* bol = _gvn.transform( new(C, 2) BoolNode(cmp, BoolTest::eq) );
2428   IfNode* iff = create_and_xform_if(control(), bol, prob, COUNT_UNKNOWN);
2429   set_control( _gvn.transform( new(C, 1) IfTrueNode (iff) ));
2430   Node* fail = _gvn.transform( new(C, 1) IfFalseNode(iff) );
2431 
2432   const TypeOopPtr* recv_xtype = tklass->as_instance_type();
2433   assert(recv_xtype->klass_is_exact(), "");
2434 
2435   // Subsume downstream occurrences of receiver with a cast to
2436   // recv_xtype, since now we know what the type will be.
2437   Node* cast = new(C, 2) CheckCastPPNode(control(), receiver, recv_xtype);
2438   (*casted_receiver) = _gvn.transform(cast);
2439   // (User must make the replace_in_map call.)
2440 
2441   return fail;
2442 }
2443 
2444 
2445 //-------------------------------gen_instanceof--------------------------------
2446 // Generate an instance-of idiom.  Used by both the instance-of bytecode
2447 // and the reflective instance-of call.
2448 Node* GraphKit::gen_instanceof( Node *subobj, Node* superklass ) {
2449   C->set_has_split_ifs(true); // Has chance for split-if optimization
2450   assert( !stopped(), "dead parse path should be checked in callers" );
2451   assert(!TypePtr::NULL_PTR->higher_equal(_gvn.type(superklass)->is_klassptr()),
2452          "must check for not-null not-dead klass in callers");
2453 
2454   // Make the merge point
2455   enum { _obj_path = 1, _fail_path, _null_path, PATH_LIMIT };
2456   RegionNode* region = new(C, PATH_LIMIT) RegionNode(PATH_LIMIT);
2457   Node*       phi    = new(C, PATH_LIMIT) PhiNode(region, TypeInt::BOOL);
2458   C->set_has_split_ifs(true); // Has chance for split-if optimization
2459 
2460   // Null check; get casted pointer; set region slot 3
2461   Node* null_ctl = top();
2462   Node* not_null_obj = null_check_oop(subobj, &null_ctl);
2463 
2464   // If not_null_obj is dead, only null-path is taken
2465   if (stopped()) {              // Doing instance-of on a NULL?
2466     set_control(null_ctl);
2467     return intcon(0);
2468   }
2469   region->init_req(_null_path, null_ctl);
2470   phi   ->init_req(_null_path, intcon(0)); // Set null path value
2471 
2472   // Load the object's klass
2473   Node* obj_klass = load_object_klass(not_null_obj);
2474 
2475   // Generate the subtype check
2476   Node* not_subtype_ctrl = gen_subtype_check(obj_klass, superklass);
2477 
2478   // Plug in the success path to the general merge in slot 1.
2479   region->init_req(_obj_path, control());
2480   phi   ->init_req(_obj_path, intcon(1));
2481 
2482   // Plug in the failing path to the general merge in slot 2.
2483   region->init_req(_fail_path, not_subtype_ctrl);
2484   phi   ->init_req(_fail_path, intcon(0));
2485 
2486   // Return final merged results
2487   set_control( _gvn.transform(region) );
2488   record_for_igvn(region);
2489   return _gvn.transform(phi);
2490 }
2491 
2492 //-------------------------------gen_checkcast---------------------------------
2493 // Generate a checkcast idiom.  Used by both the checkcast bytecode and the
2494 // array store bytecode.  Stack must be as-if BEFORE doing the bytecode so the
2495 // uncommon-trap paths work.  Adjust stack after this call.
2496 // If failure_control is supplied and not null, it is filled in with
2497 // the control edge for the cast failure.  Otherwise, an appropriate
2498 // uncommon trap or exception is thrown.
2499 Node* GraphKit::gen_checkcast(Node *obj, Node* superklass,
2500                               Node* *failure_control) {
2501   kill_dead_locals();           // Benefit all the uncommon traps
2502   const TypeKlassPtr *tk = _gvn.type(superklass)->is_klassptr();
2503   const Type *toop = TypeOopPtr::make_from_klass(tk->klass());
2504 
2505   // Fast cutout:  Check the case that the cast is vacuously true.
2506   // This detects the common cases where the test will short-circuit
2507   // away completely.  We do this before we perform the null check,
2508   // because if the test is going to turn into zero code, we don't
2509   // want a residual null check left around.  (Causes a slowdown,
2510   // for example, in some objArray manipulations, such as a[i]=a[j].)
2511   if (tk->singleton()) {
2512     const TypeOopPtr* objtp = _gvn.type(obj)->isa_oopptr();
2513     if (objtp != NULL && objtp->klass() != NULL) {
2514       switch (static_subtype_check(tk->klass(), objtp->klass())) {
2515       case SSC_always_true:
2516         return obj;
2517       case SSC_always_false:
2518         // It needs a null check because a null will *pass* the cast check.
2519         // A non-null value will always produce an exception.
2520         return do_null_assert(obj, T_OBJECT);
2521       }
2522     }
2523   }
2524 
2525   ciProfileData* data = NULL;
2526   if (failure_control == NULL) {        // use MDO in regular case only
2527     assert(java_bc() == Bytecodes::_aastore ||
2528            java_bc() == Bytecodes::_checkcast,
2529            "interpreter profiles type checks only for these BCs");
2530     data = method()->method_data()->bci_to_data(bci());
2531   }
2532 
2533   // Make the merge point
2534   enum { _obj_path = 1, _null_path, PATH_LIMIT };
2535   RegionNode* region = new (C, PATH_LIMIT) RegionNode(PATH_LIMIT);
2536   Node*       phi    = new (C, PATH_LIMIT) PhiNode(region, toop);
2537   C->set_has_split_ifs(true); // Has chance for split-if optimization
2538 
2539   // Use null-cast information if it is available
2540   bool never_see_null = false;
2541   // If we see an unexpected null at a check-cast we record it and force a
2542   // recompile; the offending check-cast will be compiled to handle NULLs.
2543   // If we see several offending BCIs, then all checkcasts in the
2544   // method will be compiled to handle NULLs.
2545   if (UncommonNullCast            // Cutout for this technique
2546       && failure_control == NULL  // regular case
2547       && obj != null()            // And not the -Xcomp stupid case?
2548       && !too_many_traps(Deoptimization::Reason_null_check)) {
2549     // Finally, check the "null_seen" bit from the interpreter.
2550     if (data == NULL || !data->as_BitData()->null_seen()) {
2551       never_see_null = true;
2552     }
2553   }
2554 
2555   // Null check; get casted pointer; set region slot 3
2556   Node* null_ctl = top();
2557   Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null);
2558 
2559   // If not_null_obj is dead, only null-path is taken
2560   if (stopped()) {              // Doing instance-of on a NULL?
2561     set_control(null_ctl);
2562     return null();
2563   }
2564   region->init_req(_null_path, null_ctl);
2565   phi   ->init_req(_null_path, null());  // Set null path value
2566 
2567   Node* cast_obj = NULL;        // the casted version of the object
2568 
2569   // If the profile has seen exactly one type, narrow to that type.
2570   // (The subsequent subtype check will always fold up.)
2571   if (UseTypeProfile && TypeProfileCasts && data != NULL &&
2572       // Counter has never been decremented (due to cast failure).
2573       // ...This is a reasonable thing to expect.  It is true of
2574       // all casts inserted by javac to implement generic types.
2575       data->as_CounterData()->count() >= 0 &&
2576       !too_many_traps(Deoptimization::Reason_class_check)) {
2577     // (No, this isn't a call, but it's enough like a virtual call
2578     // to use the same ciMethod accessor to get the profile info...)
2579     ciCallProfile profile = method()->call_profile_at_bci(bci());
2580     if (profile.count() >= 0 &&         // no cast failures here
2581         profile.has_receiver(0) &&
2582         profile.morphism() == 1) {
2583       ciKlass* exact_kls = profile.receiver(0);
2584       int ssc = static_subtype_check(tk->klass(), exact_kls);
2585       if (ssc == SSC_always_true) {
2586         // If we narrow the type to match what the type profile sees,
2587         // we can then remove the rest of the cast.
2588         // This is a win, even if the exact_kls is very specific,
2589         // because downstream operations, such as method calls,
2590         // will often benefit from the sharper type.
2591         Node* exact_obj = not_null_obj; // will get updated in place...
2592         Node* slow_ctl  = type_check_receiver(exact_obj, exact_kls, 1.0,
2593                                               &exact_obj);
2594         { PreserveJVMState pjvms(this);
2595           set_control(slow_ctl);
2596           uncommon_trap(Deoptimization::Reason_class_check,
2597                         Deoptimization::Action_maybe_recompile);
2598         }
2599         if (failure_control != NULL) // failure is now impossible
2600           (*failure_control) = top();
2601         replace_in_map(not_null_obj, exact_obj);
2602         // adjust the type of the phi to the exact klass:
2603         phi->raise_bottom_type(_gvn.type(exact_obj)->meet(TypePtr::NULL_PTR));
2604         cast_obj = exact_obj;
2605       }
2606       // assert(cast_obj != NULL)... except maybe the profile lied to us.
2607     }
2608   }
2609 
2610   if (cast_obj == NULL) {
2611     // Load the object's klass
2612     Node* obj_klass = load_object_klass(not_null_obj);
2613 
2614     // Generate the subtype check
2615     Node* not_subtype_ctrl = gen_subtype_check( obj_klass, superklass );
2616 
2617     // Plug in success path into the merge
2618     cast_obj = _gvn.transform(new (C, 2) CheckCastPPNode(control(),
2619                                                          not_null_obj, toop));
2620     // Failure path ends in uncommon trap (or may be dead - failure impossible)
2621     if (failure_control == NULL) {
2622       if (not_subtype_ctrl != top()) { // If failure is possible
2623         PreserveJVMState pjvms(this);
2624         set_control(not_subtype_ctrl);
2625         builtin_throw(Deoptimization::Reason_class_check, obj_klass);
2626       }
2627     } else {
2628       (*failure_control) = not_subtype_ctrl;
2629     }
2630   }
2631 
2632   region->init_req(_obj_path, control());
2633   phi   ->init_req(_obj_path, cast_obj);
2634 
2635   // A merge of NULL or Casted-NotNull obj
2636   Node* res = _gvn.transform(phi);
2637 
2638   // Note I do NOT always 'replace_in_map(obj,result)' here.
2639   //  if( tk->klass()->can_be_primary_super()  )
2640     // This means that if I successfully store an Object into an array-of-String
2641     // I 'forget' that the Object is really now known to be a String.  I have to
2642     // do this because we don't have true union types for interfaces - if I store
2643     // a Baz into an array-of-Interface and then tell the optimizer it's an
2644     // Interface, I forget that it's also a Baz and cannot do Baz-like field
2645     // references to it.  FIX THIS WHEN UNION TYPES APPEAR!
2646   //  replace_in_map( obj, res );
2647 
2648   // Return final merged results
2649   set_control( _gvn.transform(region) );
2650   record_for_igvn(region);
2651   return res;
2652 }
2653 
2654 //------------------------------next_monitor-----------------------------------
2655 // What number should be given to the next monitor?
2656 int GraphKit::next_monitor() {
2657   int current = jvms()->monitor_depth()* C->sync_stack_slots();
2658   int next = current + C->sync_stack_slots();
2659   // Keep the toplevel high water mark current:
2660   if (C->fixed_slots() < next)  C->set_fixed_slots(next);
2661   return current;
2662 }
2663 
2664 //------------------------------insert_mem_bar---------------------------------
2665 // Memory barrier to avoid floating things around
2666 // The membar serves as a pinch point between both control and all memory slices.
2667 Node* GraphKit::insert_mem_bar(int opcode, Node* precedent) {
2668   MemBarNode* mb = MemBarNode::make(C, opcode, Compile::AliasIdxBot, precedent);
2669   mb->init_req(TypeFunc::Control, control());
2670   mb->init_req(TypeFunc::Memory,  reset_memory());
2671   Node* membar = _gvn.transform(mb);
2672   set_control(_gvn.transform(new (C, 1) ProjNode(membar,TypeFunc::Control) ));
2673   set_all_memory_call(membar);
2674   return membar;
2675 }
2676 
2677 //-------------------------insert_mem_bar_volatile----------------------------
2678 // Memory barrier to avoid floating things around
2679 // The membar serves as a pinch point between both control and memory(alias_idx).
2680 // If you want to make a pinch point on all memory slices, do not use this
2681 // function (even with AliasIdxBot); use insert_mem_bar() instead.
2682 Node* GraphKit::insert_mem_bar_volatile(int opcode, int alias_idx, Node* precedent) {
2683   // When Parse::do_put_xxx updates a volatile field, it appends a series
2684   // of MemBarVolatile nodes, one for *each* volatile field alias category.
2685   // The first membar is on the same memory slice as the field store opcode.
2686   // This forces the membar to follow the store.  (Bug 6500685 broke this.)
2687   // All the other membars (for other volatile slices, including AliasIdxBot,
2688   // which stands for all unknown volatile slices) are control-dependent
2689   // on the first membar.  This prevents later volatile loads or stores
2690   // from sliding up past the just-emitted store.
2691 
2692   MemBarNode* mb = MemBarNode::make(C, opcode, alias_idx, precedent);
2693   mb->set_req(TypeFunc::Control,control());
2694   if (alias_idx == Compile::AliasIdxBot) {
2695     mb->set_req(TypeFunc::Memory, merged_memory()->base_memory());
2696   } else {
2697     assert(!(opcode == Op_Initialize && alias_idx != Compile::AliasIdxRaw), "fix caller");
2698     mb->set_req(TypeFunc::Memory, memory(alias_idx));
2699   }
2700   Node* membar = _gvn.transform(mb);
2701   set_control(_gvn.transform(new (C, 1) ProjNode(membar, TypeFunc::Control)));
2702   if (alias_idx == Compile::AliasIdxBot) {
2703     merged_memory()->set_base_memory(_gvn.transform(new (C, 1) ProjNode(membar, TypeFunc::Memory)));
2704   } else {
2705     set_memory(_gvn.transform(new (C, 1) ProjNode(membar, TypeFunc::Memory)),alias_idx);
2706   }
2707   return membar;
2708 }
2709 
2710 //------------------------------shared_lock------------------------------------
2711 // Emit locking code.
2712 FastLockNode* GraphKit::shared_lock(Node* obj) {
2713   // bci is either a monitorenter bc or InvocationEntryBci
2714   // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
2715   assert(SynchronizationEntryBCI == InvocationEntryBci, "");
2716 
2717   if( !GenerateSynchronizationCode )
2718     return NULL;                // Not locking things?
2719   if (stopped())                // Dead monitor?
2720     return NULL;
2721 
2722   assert(dead_locals_are_killed(), "should kill locals before sync. point");
2723 
2724   // Box the stack location
2725   Node* box = _gvn.transform(new (C, 1) BoxLockNode(next_monitor()));
2726   Node* mem = reset_memory();
2727 
2728   FastLockNode * flock = _gvn.transform(new (C, 3) FastLockNode(0, obj, box) )->as_FastLock();
2729   if (PrintPreciseBiasedLockingStatistics) {
2730     // Create the counters for this fast lock.
2731     flock->create_lock_counter(sync_jvms()); // sync_jvms used to get current bci
2732   }
2733   // Add monitor to debug info for the slow path.  If we block inside the
2734   // slow path and de-opt, we need the monitor hanging around
2735   map()->push_monitor( flock );
2736 
2737   const TypeFunc *tf = LockNode::lock_type();
2738   LockNode *lock = new (C, tf->domain()->cnt()) LockNode(C, tf);
2739 
2740   lock->init_req( TypeFunc::Control, control() );
2741   lock->init_req( TypeFunc::Memory , mem );
2742   lock->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
2743   lock->init_req( TypeFunc::FramePtr, frameptr() );
2744   lock->init_req( TypeFunc::ReturnAdr, top() );
2745 
2746   lock->init_req(TypeFunc::Parms + 0, obj);
2747   lock->init_req(TypeFunc::Parms + 1, box);
2748   lock->init_req(TypeFunc::Parms + 2, flock);
2749   add_safepoint_edges(lock);
2750 
2751   lock = _gvn.transform( lock )->as_Lock();
2752 
2753   // lock has no side-effects, sets few values
2754   set_predefined_output_for_runtime_call(lock, mem, TypeRawPtr::BOTTOM);
2755 
2756   insert_mem_bar(Op_MemBarAcquire);
2757 
2758   // Add this to the worklist so that the lock can be eliminated
2759   record_for_igvn(lock);
2760 
2761 #ifndef PRODUCT
2762   if (PrintLockStatistics) {
2763     // Update the counter for this lock.  Don't bother using an atomic
2764     // operation since we don't require absolute accuracy.
2765     lock->create_lock_counter(map()->jvms());
2766     int adr_type = Compile::AliasIdxRaw;
2767     Node* counter_addr = makecon(TypeRawPtr::make(lock->counter()->addr()));
2768     Node* cnt  = make_load(NULL, counter_addr, TypeInt::INT, T_INT, adr_type);
2769     Node* incr = _gvn.transform(new (C, 3) AddINode(cnt, _gvn.intcon(1)));
2770     store_to_memory(control(), counter_addr, incr, T_INT, adr_type);
2771   }
2772 #endif
2773 
2774   return flock;
2775 }
2776 
2777 
2778 //------------------------------shared_unlock----------------------------------
2779 // Emit unlocking code.
2780 void GraphKit::shared_unlock(Node* box, Node* obj) {
2781   // bci is either a monitorenter bc or InvocationEntryBci
2782   // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
2783   assert(SynchronizationEntryBCI == InvocationEntryBci, "");
2784 
2785   if( !GenerateSynchronizationCode )
2786     return;
2787   if (stopped()) {               // Dead monitor?
2788     map()->pop_monitor();        // Kill monitor from debug info
2789     return;
2790   }
2791 
2792   // Memory barrier to avoid floating things down past the locked region
2793   insert_mem_bar(Op_MemBarRelease);
2794 
2795   const TypeFunc *tf = OptoRuntime::complete_monitor_exit_Type();
2796   UnlockNode *unlock = new (C, tf->domain()->cnt()) UnlockNode(C, tf);
2797   uint raw_idx = Compile::AliasIdxRaw;
2798   unlock->init_req( TypeFunc::Control, control() );
2799   unlock->init_req( TypeFunc::Memory , memory(raw_idx) );
2800   unlock->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
2801   unlock->init_req( TypeFunc::FramePtr, frameptr() );
2802   unlock->init_req( TypeFunc::ReturnAdr, top() );
2803 
2804   unlock->init_req(TypeFunc::Parms + 0, obj);
2805   unlock->init_req(TypeFunc::Parms + 1, box);
2806   unlock = _gvn.transform(unlock)->as_Unlock();
2807 
2808   Node* mem = reset_memory();
2809 
2810   // unlock has no side-effects, sets few values
2811   set_predefined_output_for_runtime_call(unlock, mem, TypeRawPtr::BOTTOM);
2812 
2813   // Kill monitor from debug info
2814   map()->pop_monitor( );
2815 }
2816 
2817 //-------------------------------get_layout_helper-----------------------------
2818 // If the given klass is a constant or known to be an array,
2819 // fetch the constant layout helper value into constant_value
2820 // and return (Node*)NULL.  Otherwise, load the non-constant
2821 // layout helper value, and return the node which represents it.
2822 // This two-faced routine is useful because allocation sites
2823 // almost always feature constant types.
2824 Node* GraphKit::get_layout_helper(Node* klass_node, jint& constant_value) {
2825   const TypeKlassPtr* inst_klass = _gvn.type(klass_node)->isa_klassptr();
2826   if (!StressReflectiveCode && inst_klass != NULL) {
2827     ciKlass* klass = inst_klass->klass();
2828     bool    xklass = inst_klass->klass_is_exact();
2829     if (xklass || klass->is_array_klass()) {
2830       jint lhelper = klass->layout_helper();
2831       if (lhelper != Klass::_lh_neutral_value) {
2832         constant_value = lhelper;
2833         return (Node*) NULL;
2834       }
2835     }
2836   }
2837   constant_value = Klass::_lh_neutral_value;  // put in a known value
2838   Node* lhp = basic_plus_adr(klass_node, klass_node, Klass::layout_helper_offset_in_bytes() + sizeof(oopDesc));
2839   return make_load(NULL, lhp, TypeInt::INT, T_INT);
2840 }
2841 
2842 // We just put in an allocate/initialize with a big raw-memory effect.
2843 // Hook selected additional alias categories on the initialization.
2844 static void hook_memory_on_init(GraphKit& kit, int alias_idx,
2845                                 MergeMemNode* init_in_merge,
2846                                 Node* init_out_raw) {
2847   DEBUG_ONLY(Node* init_in_raw = init_in_merge->base_memory());
2848   assert(init_in_merge->memory_at(alias_idx) == init_in_raw, "");
2849 
2850   Node* prevmem = kit.memory(alias_idx);
2851   init_in_merge->set_memory_at(alias_idx, prevmem);
2852   kit.set_memory(init_out_raw, alias_idx);
2853 }
2854 
2855 //---------------------------set_output_for_allocation-------------------------
2856 Node* GraphKit::set_output_for_allocation(AllocateNode* alloc,
2857                                           const TypeOopPtr* oop_type,
2858                                           bool raw_mem_only) {
2859   int rawidx = Compile::AliasIdxRaw;
2860   alloc->set_req( TypeFunc::FramePtr, frameptr() );
2861   add_safepoint_edges(alloc);
2862   Node* allocx = _gvn.transform(alloc);
2863   set_control( _gvn.transform(new (C, 1) ProjNode(allocx, TypeFunc::Control) ) );
2864   // create memory projection for i_o
2865   set_memory ( _gvn.transform( new (C, 1) ProjNode(allocx, TypeFunc::Memory, true) ), rawidx );
2866   make_slow_call_ex(allocx, env()->OutOfMemoryError_klass(), true);
2867 
2868   // create a memory projection as for the normal control path
2869   Node* malloc = _gvn.transform(new (C, 1) ProjNode(allocx, TypeFunc::Memory));
2870   set_memory(malloc, rawidx);
2871 
2872   // a normal slow-call doesn't change i_o, but an allocation does
2873   // we create a separate i_o projection for the normal control path
2874   set_i_o(_gvn.transform( new (C, 1) ProjNode(allocx, TypeFunc::I_O, false) ) );
2875   Node* rawoop = _gvn.transform( new (C, 1) ProjNode(allocx, TypeFunc::Parms) );
2876 
2877   // put in an initialization barrier
2878   InitializeNode* init = insert_mem_bar_volatile(Op_Initialize, rawidx,
2879                                                  rawoop)->as_Initialize();
2880   assert(alloc->initialization() == init,  "2-way macro link must work");
2881   assert(init ->allocation()     == alloc, "2-way macro link must work");
2882   if (ReduceFieldZeroing && !raw_mem_only) {
2883     // Extract memory strands which may participate in the new object's
2884     // initialization, and source them from the new InitializeNode.
2885     // This will allow us to observe initializations when they occur,
2886     // and link them properly (as a group) to the InitializeNode.
2887     assert(init->in(InitializeNode::Memory) == malloc, "");
2888     MergeMemNode* minit_in = MergeMemNode::make(C, malloc);
2889     init->set_req(InitializeNode::Memory, minit_in);
2890     record_for_igvn(minit_in); // fold it up later, if possible
2891     Node* minit_out = memory(rawidx);
2892     assert(minit_out->is_Proj() && minit_out->in(0) == init, "");
2893     if (oop_type->isa_aryptr()) {
2894       const TypePtr* telemref = oop_type->add_offset(Type::OffsetBot);
2895       int            elemidx  = C->get_alias_index(telemref);
2896       hook_memory_on_init(*this, elemidx, minit_in, minit_out);
2897     } else if (oop_type->isa_instptr()) {
2898       ciInstanceKlass* ik = oop_type->klass()->as_instance_klass();
2899       for (int i = 0, len = ik->nof_nonstatic_fields(); i < len; i++) {
2900         ciField* field = ik->nonstatic_field_at(i);
2901         if (field->offset() >= TrackedInitializationLimit * HeapWordSize)
2902           continue;  // do not bother to track really large numbers of fields
2903         // Find (or create) the alias category for this field:
2904         int fieldidx = C->alias_type(field)->index();
2905         hook_memory_on_init(*this, fieldidx, minit_in, minit_out);
2906       }
2907     }
2908   }
2909 
2910   // Cast raw oop to the real thing...
2911   Node* javaoop = new (C, 2) CheckCastPPNode(control(), rawoop, oop_type);
2912   javaoop = _gvn.transform(javaoop);
2913   C->set_recent_alloc(control(), javaoop);
2914   assert(just_allocated_object(control()) == javaoop, "just allocated");
2915 
2916 #ifdef ASSERT
2917   { // Verify that the AllocateNode::Ideal_allocation recognizers work:
2918     assert(AllocateNode::Ideal_allocation(rawoop, &_gvn) == alloc,
2919            "Ideal_allocation works");
2920     assert(AllocateNode::Ideal_allocation(javaoop, &_gvn) == alloc,
2921            "Ideal_allocation works");
2922     if (alloc->is_AllocateArray()) {
2923       assert(AllocateArrayNode::Ideal_array_allocation(rawoop, &_gvn) == alloc->as_AllocateArray(),
2924              "Ideal_allocation works");
2925       assert(AllocateArrayNode::Ideal_array_allocation(javaoop, &_gvn) == alloc->as_AllocateArray(),
2926              "Ideal_allocation works");
2927     } else {
2928       assert(alloc->in(AllocateNode::ALength)->is_top(), "no length, please");
2929     }
2930   }
2931 #endif //ASSERT
2932 
2933   return javaoop;
2934 }
2935 
2936 //---------------------------new_instance--------------------------------------
2937 // This routine takes a klass_node which may be constant (for a static type)
2938 // or may be non-constant (for reflective code).  It will work equally well
2939 // for either, and the graph will fold nicely if the optimizer later reduces
2940 // the type to a constant.
2941 // The optional arguments are for specialized use by intrinsics:
2942 //  - If 'extra_slow_test' if not null is an extra condition for the slow-path.
2943 //  - If 'raw_mem_only', do not cast the result to an oop.
2944 //  - If 'return_size_val', report the the total object size to the caller.
2945 Node* GraphKit::new_instance(Node* klass_node,
2946                              Node* extra_slow_test,
2947                              bool raw_mem_only, // affect only raw memory
2948                              Node* *return_size_val) {
2949   // Compute size in doublewords
2950   // The size is always an integral number of doublewords, represented
2951   // as a positive bytewise size stored in the klass's layout_helper.
2952   // The layout_helper also encodes (in a low bit) the need for a slow path.
2953   jint  layout_con = Klass::_lh_neutral_value;
2954   Node* layout_val = get_layout_helper(klass_node, layout_con);
2955   int   layout_is_con = (layout_val == NULL);
2956 
2957   if (extra_slow_test == NULL)  extra_slow_test = intcon(0);
2958   // Generate the initial go-slow test.  It's either ALWAYS (return a
2959   // Node for 1) or NEVER (return a NULL) or perhaps (in the reflective
2960   // case) a computed value derived from the layout_helper.
2961   Node* initial_slow_test = NULL;
2962   if (layout_is_con) {
2963     assert(!StressReflectiveCode, "stress mode does not use these paths");
2964     bool must_go_slow = Klass::layout_helper_needs_slow_path(layout_con);
2965     initial_slow_test = must_go_slow? intcon(1): extra_slow_test;
2966 
2967   } else {   // reflective case
2968     // This reflective path is used by Unsafe.allocateInstance.
2969     // (It may be stress-tested by specifying StressReflectiveCode.)
2970     // Basically, we want to get into the VM is there's an illegal argument.
2971     Node* bit = intcon(Klass::_lh_instance_slow_path_bit);
2972     initial_slow_test = _gvn.transform( new (C, 3) AndINode(layout_val, bit) );
2973     if (extra_slow_test != intcon(0)) {
2974       initial_slow_test = _gvn.transform( new (C, 3) OrINode(initial_slow_test, extra_slow_test) );
2975     }
2976     // (Macro-expander will further convert this to a Bool, if necessary.)
2977   }
2978 
2979   // Find the size in bytes.  This is easy; it's the layout_helper.
2980   // The size value must be valid even if the slow path is taken.
2981   Node* size = NULL;
2982   if (layout_is_con) {
2983     size = MakeConX(Klass::layout_helper_size_in_bytes(layout_con));
2984   } else {   // reflective case
2985     // This reflective path is used by clone and Unsafe.allocateInstance.
2986     size = ConvI2X(layout_val);
2987 
2988     // Clear the low bits to extract layout_helper_size_in_bytes:
2989     assert((int)Klass::_lh_instance_slow_path_bit < BytesPerLong, "clear bit");
2990     Node* mask = MakeConX(~ (intptr_t)right_n_bits(LogBytesPerLong));
2991     size = _gvn.transform( new (C, 3) AndXNode(size, mask) );
2992   }
2993   if (return_size_val != NULL) {
2994     (*return_size_val) = size;
2995   }
2996 
2997   // This is a precise notnull oop of the klass.
2998   // (Actually, it need not be precise if this is a reflective allocation.)
2999   // It's what we cast the result to.
3000   const TypeKlassPtr* tklass = _gvn.type(klass_node)->isa_klassptr();
3001   if (!tklass)  tklass = TypeKlassPtr::OBJECT;
3002   const TypeOopPtr* oop_type = tklass->as_instance_type();
3003 
3004   // Now generate allocation code
3005 
3006   // The entire memory state is needed for slow path of the allocation
3007   // since GC and deoptimization can happened.
3008   Node *mem = reset_memory();
3009   set_all_memory(mem); // Create new memory state
3010 
3011   AllocateNode* alloc
3012     = new (C, AllocateNode::ParmLimit)
3013         AllocateNode(C, AllocateNode::alloc_type(),
3014                      control(), mem, i_o(),
3015                      size, klass_node,
3016                      initial_slow_test);
3017 
3018   return set_output_for_allocation(alloc, oop_type, raw_mem_only);
3019 }
3020 
3021 //-------------------------------new_array-------------------------------------
3022 // helper for both newarray and anewarray
3023 // The 'length' parameter is (obviously) the length of the array.
3024 // See comments on new_instance for the meaning of the other arguments.
3025 Node* GraphKit::new_array(Node* klass_node,     // array klass (maybe variable)
3026                           Node* length,         // number of array elements
3027                           int   nargs,          // number of arguments to push back for uncommon trap
3028                           bool raw_mem_only,    // affect only raw memory
3029                           Node* *return_size_val) {
3030   jint  layout_con = Klass::_lh_neutral_value;
3031   Node* layout_val = get_layout_helper(klass_node, layout_con);
3032   int   layout_is_con = (layout_val == NULL);
3033 
3034   if (!layout_is_con && !StressReflectiveCode &&
3035       !too_many_traps(Deoptimization::Reason_class_check)) {
3036     // This is a reflective array creation site.
3037     // Optimistically assume that it is a subtype of Object[],
3038     // so that we can fold up all the address arithmetic.
3039     layout_con = Klass::array_layout_helper(T_OBJECT);
3040     Node* cmp_lh = _gvn.transform( new(C, 3) CmpINode(layout_val, intcon(layout_con)) );
3041     Node* bol_lh = _gvn.transform( new(C, 2) BoolNode(cmp_lh, BoolTest::eq) );
3042     { BuildCutout unless(this, bol_lh, PROB_MAX);
3043       _sp += nargs;
3044       uncommon_trap(Deoptimization::Reason_class_check,
3045                     Deoptimization::Action_maybe_recompile);
3046     }
3047     layout_val = NULL;
3048     layout_is_con = true;
3049   }
3050 
3051   // Generate the initial go-slow test.  Make sure we do not overflow
3052   // if length is huge (near 2Gig) or negative!  We do not need
3053   // exact double-words here, just a close approximation of needed
3054   // double-words.  We can't add any offset or rounding bits, lest we
3055   // take a size -1 of bytes and make it positive.  Use an unsigned
3056   // compare, so negative sizes look hugely positive.
3057   int fast_size_limit = FastAllocateSizeLimit;
3058   if (layout_is_con) {
3059     assert(!StressReflectiveCode, "stress mode does not use these paths");
3060     // Increase the size limit if we have exact knowledge of array type.
3061     int log2_esize = Klass::layout_helper_log2_element_size(layout_con);
3062     fast_size_limit <<= (LogBytesPerLong - log2_esize);
3063   }
3064 
3065   Node* initial_slow_cmp  = _gvn.transform( new (C, 3) CmpUNode( length, intcon( fast_size_limit ) ) );
3066   Node* initial_slow_test = _gvn.transform( new (C, 2) BoolNode( initial_slow_cmp, BoolTest::gt ) );
3067   if (initial_slow_test->is_Bool()) {
3068     // Hide it behind a CMoveI, or else PhaseIdealLoop::split_up will get sick.
3069     initial_slow_test = initial_slow_test->as_Bool()->as_int_value(&_gvn);
3070   }
3071 
3072   // --- Size Computation ---
3073   // array_size = round_to_heap(array_header + (length << elem_shift));
3074   // where round_to_heap(x) == round_to(x, MinObjAlignmentInBytes)
3075   // and round_to(x, y) == ((x + y-1) & ~(y-1))
3076   // The rounding mask is strength-reduced, if possible.
3077   int round_mask = MinObjAlignmentInBytes - 1;
3078   Node* header_size = NULL;
3079   int   header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
3080   // (T_BYTE has the weakest alignment and size restrictions...)
3081   if (layout_is_con) {
3082     int       hsize  = Klass::layout_helper_header_size(layout_con);
3083     int       eshift = Klass::layout_helper_log2_element_size(layout_con);
3084     BasicType etype  = Klass::layout_helper_element_type(layout_con);
3085     if ((round_mask & ~right_n_bits(eshift)) == 0)
3086       round_mask = 0;  // strength-reduce it if it goes away completely
3087     assert((hsize & right_n_bits(eshift)) == 0, "hsize is pre-rounded");
3088     assert(header_size_min <= hsize, "generic minimum is smallest");
3089     header_size_min = hsize;
3090     header_size = intcon(hsize + round_mask);
3091   } else {
3092     Node* hss   = intcon(Klass::_lh_header_size_shift);
3093     Node* hsm   = intcon(Klass::_lh_header_size_mask);
3094     Node* hsize = _gvn.transform( new(C, 3) URShiftINode(layout_val, hss) );
3095     hsize       = _gvn.transform( new(C, 3) AndINode(hsize, hsm) );
3096     Node* mask  = intcon(round_mask);
3097     header_size = _gvn.transform( new(C, 3) AddINode(hsize, mask) );
3098   }
3099 
3100   Node* elem_shift = NULL;
3101   if (layout_is_con) {
3102     int eshift = Klass::layout_helper_log2_element_size(layout_con);
3103     if (eshift != 0)
3104       elem_shift = intcon(eshift);
3105   } else {
3106     // There is no need to mask or shift this value.
3107     // The semantics of LShiftINode include an implicit mask to 0x1F.
3108     assert(Klass::_lh_log2_element_size_shift == 0, "use shift in place");
3109     elem_shift = layout_val;
3110   }
3111 
3112   // Transition to native address size for all offset calculations:
3113   Node* lengthx = ConvI2X(length);
3114   Node* headerx = ConvI2X(header_size);
3115 #ifdef _LP64
3116   { const TypeLong* tllen = _gvn.find_long_type(lengthx);
3117     if (tllen != NULL && tllen->_lo < 0) {
3118       // Add a manual constraint to a positive range.  Cf. array_element_address.
3119       jlong size_max = arrayOopDesc::max_array_length(T_BYTE);
3120       if (size_max > tllen->_hi)  size_max = tllen->_hi;
3121       const TypeLong* tlcon = TypeLong::make(CONST64(0), size_max, Type::WidenMin);
3122       lengthx = _gvn.transform( new (C, 2) ConvI2LNode(length, tlcon));
3123     }
3124   }
3125 #endif
3126 
3127   // Combine header size (plus rounding) and body size.  Then round down.
3128   // This computation cannot overflow, because it is used only in two
3129   // places, one where the length is sharply limited, and the other
3130   // after a successful allocation.
3131   Node* abody = lengthx;
3132   if (elem_shift != NULL)
3133     abody     = _gvn.transform( new(C, 3) LShiftXNode(lengthx, elem_shift) );
3134   Node* size  = _gvn.transform( new(C, 3) AddXNode(headerx, abody) );
3135   if (round_mask != 0) {
3136     Node* mask = MakeConX(~round_mask);
3137     size       = _gvn.transform( new(C, 3) AndXNode(size, mask) );
3138   }
3139   // else if round_mask == 0, the size computation is self-rounding
3140 
3141   if (return_size_val != NULL) {
3142     // This is the size
3143     (*return_size_val) = size;
3144   }
3145 
3146   // Now generate allocation code
3147 
3148   // The entire memory state is needed for slow path of the allocation
3149   // since GC and deoptimization can happened.
3150   Node *mem = reset_memory();
3151   set_all_memory(mem); // Create new memory state
3152 
3153   // Create the AllocateArrayNode and its result projections
3154   AllocateArrayNode* alloc
3155     = new (C, AllocateArrayNode::ParmLimit)
3156         AllocateArrayNode(C, AllocateArrayNode::alloc_type(),
3157                           control(), mem, i_o(),
3158                           size, klass_node,
3159                           initial_slow_test,
3160                           length);
3161 
3162   // Cast to correct type.  Note that the klass_node may be constant or not,
3163   // and in the latter case the actual array type will be inexact also.
3164   // (This happens via a non-constant argument to inline_native_newArray.)
3165   // In any case, the value of klass_node provides the desired array type.
3166   const TypeInt* length_type = _gvn.find_int_type(length);
3167   const TypeOopPtr* ary_type = _gvn.type(klass_node)->is_klassptr()->as_instance_type();
3168   if (ary_type->isa_aryptr() && length_type != NULL) {
3169     // Try to get a better type than POS for the size
3170     ary_type = ary_type->is_aryptr()->cast_to_size(length_type);
3171   }
3172 
3173   Node* javaoop = set_output_for_allocation(alloc, ary_type, raw_mem_only);
3174 
3175   // Cast length on remaining path to be as narrow as possible
3176   if (map()->find_edge(length) >= 0) {
3177     Node* ccast = alloc->make_ideal_length(ary_type, &_gvn);
3178     if (ccast != length) {
3179       _gvn.set_type_bottom(ccast);
3180       record_for_igvn(ccast);
3181       replace_in_map(length, ccast);
3182     }
3183   }
3184 
3185   return javaoop;
3186 }
3187 
3188 // The following "Ideal_foo" functions are placed here because they recognize
3189 // the graph shapes created by the functions immediately above.
3190 
3191 //---------------------------Ideal_allocation----------------------------------
3192 // Given an oop pointer or raw pointer, see if it feeds from an AllocateNode.
3193 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase) {
3194   if (ptr == NULL) {     // reduce dumb test in callers
3195     return NULL;
3196   }
3197   if (ptr->is_CheckCastPP()) {  // strip a raw-to-oop cast
3198     ptr = ptr->in(1);
3199     if (ptr == NULL)  return NULL;
3200   }
3201   if (ptr->is_Proj()) {
3202     Node* allo = ptr->in(0);
3203     if (allo != NULL && allo->is_Allocate()) {
3204       return allo->as_Allocate();
3205     }
3206   }
3207   // Report failure to match.
3208   return NULL;
3209 }
3210 
3211 // Fancy version which also strips off an offset (and reports it to caller).
3212 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase,
3213                                              intptr_t& offset) {
3214   Node* base = AddPNode::Ideal_base_and_offset(ptr, phase, offset);
3215   if (base == NULL)  return NULL;
3216   return Ideal_allocation(base, phase);
3217 }
3218 
3219 // Trace Initialize <- Proj[Parm] <- Allocate
3220 AllocateNode* InitializeNode::allocation() {
3221   Node* rawoop = in(InitializeNode::RawAddress);
3222   if (rawoop->is_Proj()) {
3223     Node* alloc = rawoop->in(0);
3224     if (alloc->is_Allocate()) {
3225       return alloc->as_Allocate();
3226     }
3227   }
3228   return NULL;
3229 }
3230 
3231 // Trace Allocate -> Proj[Parm] -> Initialize
3232 InitializeNode* AllocateNode::initialization() {
3233   ProjNode* rawoop = proj_out(AllocateNode::RawAddress);
3234   if (rawoop == NULL)  return NULL;
3235   for (DUIterator_Fast imax, i = rawoop->fast_outs(imax); i < imax; i++) {
3236     Node* init = rawoop->fast_out(i);
3237     if (init->is_Initialize()) {
3238       assert(init->as_Initialize()->allocation() == this, "2-way link");
3239       return init->as_Initialize();
3240     }
3241   }
3242   return NULL;
3243 }
3244 
3245 void GraphKit::g1_write_barrier_pre(Node* obj,
3246                                     Node* adr,
3247                                     uint alias_idx,
3248                                     Node* val,
3249                                     const TypeOopPtr* val_type,
3250                                     BasicType bt) {
3251   IdealKit ideal(gvn(), control(), merged_memory(), true);
3252 #define __ ideal.
3253   __ declares_done();
3254 
3255   Node* thread = __ thread();
3256 
3257   Node* no_ctrl = NULL;
3258   Node* no_base = __ top();
3259   Node* zero = __ ConI(0);
3260 
3261   float likely  = PROB_LIKELY(0.999);
3262   float unlikely  = PROB_UNLIKELY(0.999);
3263 
3264   BasicType active_type = in_bytes(PtrQueue::byte_width_of_active()) == 4 ? T_INT : T_BYTE;
3265   assert(in_bytes(PtrQueue::byte_width_of_active()) == 4 || in_bytes(PtrQueue::byte_width_of_active()) == 1, "flag width");
3266 
3267   // Offsets into the thread
3268   const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() +  // 648
3269                                           PtrQueue::byte_offset_of_active());
3270   const int index_offset   = in_bytes(JavaThread::satb_mark_queue_offset() +  // 656
3271                                           PtrQueue::byte_offset_of_index());
3272   const int buffer_offset  = in_bytes(JavaThread::satb_mark_queue_offset() +  // 652
3273                                           PtrQueue::byte_offset_of_buf());
3274   // Now the actual pointers into the thread
3275 
3276   // set_control( ctl);
3277 
3278   Node* marking_adr = __ AddP(no_base, thread, __ ConX(marking_offset));
3279   Node* buffer_adr  = __ AddP(no_base, thread, __ ConX(buffer_offset));
3280   Node* index_adr   = __ AddP(no_base, thread, __ ConX(index_offset));
3281 
3282   // Now some of the values
3283 
3284   Node* marking = __ load(__ ctrl(), marking_adr, TypeInt::INT, active_type, Compile::AliasIdxRaw);
3285 
3286   // if (!marking)
3287   __ if_then(marking, BoolTest::ne, zero); {
3288     Node* index   = __ load(__ ctrl(), index_adr, TypeInt::INT, T_INT, Compile::AliasIdxRaw);
3289 
3290     const Type* t1 = adr->bottom_type();
3291     const Type* t2 = val->bottom_type();
3292 
3293     Node* orig = __ load(no_ctrl, adr, val_type, bt, alias_idx);
3294     // if (orig != NULL)
3295     __ if_then(orig, BoolTest::ne, null()); {
3296       Node* buffer  = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
3297 
3298       // load original value
3299       // alias_idx correct??
3300 
3301       // is the queue for this thread full?
3302       __ if_then(index, BoolTest::ne, zero, likely); {
3303 
3304         // decrement the index
3305         Node* next_index = __ SubI(index,  __ ConI(sizeof(intptr_t)));
3306         Node* next_indexX = next_index;
3307 #ifdef _LP64
3308           // We could refine the type for what it's worth
3309           // const TypeLong* lidxtype = TypeLong::make(CONST64(0), get_size_from_queue);
3310           next_indexX = _gvn.transform( new (C, 2) ConvI2LNode(next_index, TypeLong::make(0, max_jlong, Type::WidenMax)) );
3311 #endif // _LP64
3312 
3313         // Now get the buffer location we will log the original value into and store it
3314 
3315         Node *log_addr = __ AddP(no_base, buffer, next_indexX);
3316         // __ store(__ ctrl(), log_addr, orig, T_OBJECT, C->get_alias_index(TypeOopPtr::BOTTOM));
3317         __ store(__ ctrl(), log_addr, orig, T_OBJECT, Compile::AliasIdxRaw);
3318 
3319 
3320         // update the index
3321         // __ store(__ ctrl(), index_adr, next_index, T_INT, Compile::AliasIdxRaw);
3322         // This is a hack to force this store to occur before the oop store that is coming up
3323         __ store(__ ctrl(), index_adr, next_index, T_INT, C->get_alias_index(TypeOopPtr::BOTTOM));
3324 
3325       } __ else_(); {
3326 
3327         // logging buffer is full, call the runtime
3328         const TypeFunc *tf = OptoRuntime::g1_wb_pre_Type();
3329         // __ make_leaf_call(tf, OptoRuntime::g1_wb_pre_Java(), "g1_wb_pre", orig, thread);
3330         __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_pre), "g1_wb_pre", orig, thread);
3331       } __ end_if();
3332     } __ end_if();
3333   } __ end_if();
3334 
3335   __ drain_delay_transform();
3336   set_control( __ ctrl());
3337   set_all_memory( __ merged_memory());
3338 
3339 #undef __
3340 }
3341 
3342 //
3343 // Update the card table and add card address to the queue
3344 //
3345 void GraphKit::g1_mark_card(IdealKit* ideal, Node* card_adr, Node* store,  Node* index, Node* index_adr, Node* buffer, const TypeFunc* tf) {
3346 #define __ ideal->
3347   Node* zero = __ ConI(0);
3348   Node* no_base = __ top();
3349   BasicType card_bt = T_BYTE;
3350   // Smash zero into card. MUST BE ORDERED WRT TO STORE
3351   __ storeCM(__ ctrl(), card_adr, zero, store, card_bt, Compile::AliasIdxRaw);
3352 
3353   //  Now do the queue work
3354   __ if_then(index, BoolTest::ne, zero); {
3355 
3356     Node* next_index = __ SubI(index,  __ ConI(sizeof(intptr_t)));
3357     Node* next_indexX = next_index;
3358 #ifdef _LP64
3359     // We could refine the type for what it's worth
3360     // const TypeLong* lidxtype = TypeLong::make(CONST64(0), get_size_from_queue);
3361     next_indexX = _gvn.transform( new (C, 2) ConvI2LNode(next_index, TypeLong::make(0, max_jlong, Type::WidenMax)) );
3362 #endif // _LP64
3363     Node* log_addr = __ AddP(no_base, buffer, next_indexX);
3364 
3365     __ store(__ ctrl(), log_addr, card_adr, T_ADDRESS, Compile::AliasIdxRaw);
3366     __ store(__ ctrl(), index_adr, next_index, T_INT, Compile::AliasIdxRaw);
3367 
3368   } __ else_(); {
3369     __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_post), "g1_wb_post", card_adr, __ thread());
3370   } __ end_if();
3371 #undef __
3372 }
3373 
3374 void GraphKit::g1_write_barrier_post(Node* store,
3375                                      Node* obj,
3376                                      Node* adr,
3377                                      uint alias_idx,
3378                                      Node* val,
3379                                      BasicType bt,
3380                                      bool use_precise) {
3381   // If we are writing a NULL then we need no post barrier
3382 
3383   if (val != NULL && val->is_Con() && val->bottom_type() == TypePtr::NULL_PTR) {
3384     // Must be NULL
3385     const Type* t = val->bottom_type();
3386     assert(t == Type::TOP || t == TypePtr::NULL_PTR, "must be NULL");
3387     // No post barrier if writing NULLx
3388     return;
3389   }
3390 
3391   if (!use_precise) {
3392     // All card marks for a (non-array) instance are in one place:
3393     adr = obj;
3394   }
3395   // (Else it's an array (or unknown), and we want more precise card marks.)
3396   assert(adr != NULL, "");
3397 
3398   IdealKit ideal(gvn(), control(), merged_memory(), true);
3399 #define __ ideal.
3400   __ declares_done();
3401 
3402   Node* thread = __ thread();
3403 
3404   Node* no_ctrl = NULL;
3405   Node* no_base = __ top();
3406   float likely  = PROB_LIKELY(0.999);
3407   float unlikely  = PROB_UNLIKELY(0.999);
3408   Node* zero = __ ConI(0);
3409   Node* zeroX = __ ConX(0);
3410 
3411   // Get the alias_index for raw card-mark memory
3412   const TypePtr* card_type = TypeRawPtr::BOTTOM;
3413 
3414   const TypeFunc *tf = OptoRuntime::g1_wb_post_Type();
3415 
3416   // Offsets into the thread
3417   const int index_offset  = in_bytes(JavaThread::dirty_card_queue_offset() +
3418                                      PtrQueue::byte_offset_of_index());
3419   const int buffer_offset = in_bytes(JavaThread::dirty_card_queue_offset() +
3420                                      PtrQueue::byte_offset_of_buf());
3421 
3422   // Pointers into the thread
3423 
3424   Node* buffer_adr = __ AddP(no_base, thread, __ ConX(buffer_offset));
3425   Node* index_adr =  __ AddP(no_base, thread, __ ConX(index_offset));
3426 
3427   // Now some values
3428 
3429   Node* index  = __ load(no_ctrl, index_adr, TypeInt::INT, T_INT, Compile::AliasIdxRaw);
3430   Node* buffer = __ load(no_ctrl, buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
3431 
3432 
3433   // Convert the store obj pointer to an int prior to doing math on it
3434   // Use addr not obj gets accurate card marks
3435 
3436   // Node* cast = __ CastPX(no_ctrl, adr /* obj */);
3437 
3438   // Must use ctrl to prevent "integerized oop" existing across safepoint
3439   Node* cast =  __ CastPX(__ ctrl(), ( use_precise ? adr : obj ));
3440 
3441   // Divide pointer by card size
3442   Node* card_offset = __ URShiftX( cast, __ ConI(CardTableModRefBS::card_shift) );
3443 
3444   // Combine card table base and card offset
3445   Node *card_adr = __ AddP(no_base, byte_map_base_node(), card_offset );
3446 
3447   // If we know the value being stored does it cross regions?
3448 
3449   if (val != NULL) {
3450     // Does the store cause us to cross regions?
3451 
3452     // Should be able to do an unsigned compare of region_size instead of
3453     // and extra shift. Do we have an unsigned compare??
3454     // Node* region_size = __ ConI(1 << HeapRegion::LogOfHRGrainBytes);
3455     Node* xor_res =  __ URShiftX ( __ XorX( cast,  __ CastPX(__ ctrl(), val)), __ ConI(HeapRegion::LogOfHRGrainBytes));
3456 
3457     // if (xor_res == 0) same region so skip
3458     __ if_then(xor_res, BoolTest::ne, zeroX); {
3459 
3460       // No barrier if we are storing a NULL
3461       __ if_then(val, BoolTest::ne, null(), unlikely); {
3462 
3463         // Ok must mark the card if not already dirty
3464 
3465         // load the original value of the card
3466         Node* card_val = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
3467 
3468         __ if_then(card_val, BoolTest::ne, zero); {
3469           g1_mark_card(&ideal, card_adr, store, index, index_adr, buffer, tf);
3470         } __ end_if();
3471       } __ end_if();
3472     } __ end_if();
3473   } else {
3474     g1_mark_card(&ideal, card_adr, store, index, index_adr, buffer, tf);
3475   }
3476 
3477 
3478   __ drain_delay_transform();
3479   set_control( __ ctrl());
3480   set_all_memory( __ merged_memory());
3481 #undef __
3482 
3483 }