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