1 /*
   2  * Copyright (c) 2001, 2013, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "compiler/compileLog.hpp"
  27 #include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp"
  28 #include "gc_implementation/g1/heapRegion.hpp"
  29 #include "gc_interface/collectedHeap.hpp"
  30 #include "memory/barrierSet.hpp"
  31 #include "memory/cardTableModRefBS.hpp"
  32 #include "opto/addnode.hpp"
  33 #include "opto/graphKit.hpp"
  34 #include "opto/idealKit.hpp"
  35 #include "opto/locknode.hpp"
  36 #include "opto/machnode.hpp"
  37 #include "opto/parse.hpp"
  38 #include "opto/rootnode.hpp"
  39 #include "opto/runtime.hpp"
  40 #include "runtime/deoptimization.hpp"
  41 #include "runtime/sharedRuntime.hpp"
  42 
  43 //----------------------------GraphKit-----------------------------------------
  44 // Main utility constructor.
  45 GraphKit::GraphKit(JVMState* jvms)
  46   : Phase(Phase::Parser),
  47     _env(C->env()),
  48     _gvn(*C->initial_gvn())
  49 {
  50   _exceptions = jvms->map()->next_exception();
  51   if (_exceptions != NULL)  jvms->map()->set_next_exception(NULL);
  52   set_jvms(jvms);
  53 }
  54 
  55 // Private constructor for parser.
  56 GraphKit::GraphKit()
  57   : Phase(Phase::Parser),
  58     _env(C->env()),
  59     _gvn(*C->initial_gvn())
  60 {
  61   _exceptions = NULL;
  62   set_map(NULL);
  63   debug_only(_sp = -99);
  64   debug_only(set_bci(-99));
  65 }
  66 
  67 
  68 
  69 //---------------------------clean_stack---------------------------------------
  70 // Clear away rubbish from the stack area of the JVM state.
  71 // This destroys any arguments that may be waiting on the stack.
  72 void GraphKit::clean_stack(int from_sp) {
  73   SafePointNode* map      = this->map();
  74   JVMState*      jvms     = this->jvms();
  75   int            stk_size = jvms->stk_size();
  76   int            stkoff   = jvms->stkoff();
  77   Node*          top      = this->top();
  78   for (int i = from_sp; i < stk_size; i++) {
  79     if (map->in(stkoff + i) != top) {
  80       map->set_req(stkoff + i, top);
  81     }
  82   }
  83 }
  84 
  85 
  86 //--------------------------------sync_jvms-----------------------------------
  87 // Make sure our current jvms agrees with our parse state.
  88 JVMState* GraphKit::sync_jvms() const {
  89   JVMState* jvms = this->jvms();
  90   jvms->set_bci(bci());       // Record the new bci in the JVMState
  91   jvms->set_sp(sp());         // Record the new sp in the JVMState
  92   assert(jvms_in_sync(), "jvms is now in sync");
  93   return jvms;
  94 }
  95 
  96 //--------------------------------sync_jvms_for_reexecute---------------------
  97 // Make sure our current jvms agrees with our parse state.  This version
  98 // uses the reexecute_sp for reexecuting bytecodes.
  99 JVMState* GraphKit::sync_jvms_for_reexecute() {
 100   JVMState* jvms = this->jvms();
 101   jvms->set_bci(bci());          // Record the new bci in the JVMState
 102   jvms->set_sp(reexecute_sp());  // Record the new sp in the JVMState
 103   return jvms;
 104 }
 105 
 106 #ifdef ASSERT
 107 bool GraphKit::jvms_in_sync() const {
 108   Parse* parse = is_Parse();
 109   if (parse == NULL) {
 110     if (bci() !=      jvms()->bci())          return false;
 111     if (sp()  != (int)jvms()->sp())           return false;
 112     return true;
 113   }
 114   if (jvms()->method() != parse->method())    return false;
 115   if (jvms()->bci()    != parse->bci())       return false;
 116   int jvms_sp = jvms()->sp();
 117   if (jvms_sp          != parse->sp())        return false;
 118   int jvms_depth = jvms()->depth();
 119   if (jvms_depth       != parse->depth())     return false;
 120   return true;
 121 }
 122 
 123 // Local helper checks for special internal merge points
 124 // used to accumulate and merge exception states.
 125 // They are marked by the region's in(0) edge being the map itself.
 126 // Such merge points must never "escape" into the parser at large,
 127 // until they have been handed to gvn.transform.
 128 static bool is_hidden_merge(Node* reg) {
 129   if (reg == NULL)  return false;
 130   if (reg->is_Phi()) {
 131     reg = reg->in(0);
 132     if (reg == NULL)  return false;
 133   }
 134   return reg->is_Region() && reg->in(0) != NULL && reg->in(0)->is_Root();
 135 }
 136 
 137 void GraphKit::verify_map() const {
 138   if (map() == NULL)  return;  // null map is OK
 139   assert(map()->req() <= jvms()->endoff(), "no extra garbage on map");
 140   assert(!map()->has_exceptions(),    "call add_exception_states_from 1st");
 141   assert(!is_hidden_merge(control()), "call use_exception_state, not set_map");
 142 }
 143 
 144 void GraphKit::verify_exception_state(SafePointNode* ex_map) {
 145   assert(ex_map->next_exception() == NULL, "not already part of a chain");
 146   assert(has_saved_ex_oop(ex_map), "every exception state has an ex_oop");
 147 }
 148 #endif
 149 
 150 //---------------------------stop_and_kill_map---------------------------------
 151 // Set _map to NULL, signalling a stop to further bytecode execution.
 152 // First smash the current map's control to a constant, to mark it dead.
 153 void GraphKit::stop_and_kill_map() {
 154   SafePointNode* dead_map = stop();
 155   if (dead_map != NULL) {
 156     dead_map->disconnect_inputs(NULL, C); // Mark the map as killed.
 157     assert(dead_map->is_killed(), "must be so marked");
 158   }
 159 }
 160 
 161 
 162 //--------------------------------stopped--------------------------------------
 163 // Tell if _map is NULL, or control is top.
 164 bool GraphKit::stopped() {
 165   if (map() == NULL)           return true;
 166   else if (control() == top()) return true;
 167   else                         return false;
 168 }
 169 
 170 
 171 //-----------------------------has_ex_handler----------------------------------
 172 // Tell if this method or any caller method has exception handlers.
 173 bool GraphKit::has_ex_handler() {
 174   for (JVMState* jvmsp = jvms(); jvmsp != NULL; jvmsp = jvmsp->caller()) {
 175     if (jvmsp->has_method() && jvmsp->method()->has_exception_handlers()) {
 176       return true;
 177     }
 178   }
 179   return false;
 180 }
 181 
 182 //------------------------------save_ex_oop------------------------------------
 183 // Save an exception without blowing stack contents or other JVM state.
 184 void GraphKit::set_saved_ex_oop(SafePointNode* ex_map, Node* ex_oop) {
 185   assert(!has_saved_ex_oop(ex_map), "clear ex-oop before setting again");
 186   ex_map->add_req(ex_oop);
 187   debug_only(verify_exception_state(ex_map));
 188 }
 189 
 190 inline static Node* common_saved_ex_oop(SafePointNode* ex_map, bool clear_it) {
 191   assert(GraphKit::has_saved_ex_oop(ex_map), "ex_oop must be there");
 192   Node* ex_oop = ex_map->in(ex_map->req()-1);
 193   if (clear_it)  ex_map->del_req(ex_map->req()-1);
 194   return ex_oop;
 195 }
 196 
 197 //-----------------------------saved_ex_oop------------------------------------
 198 // Recover a saved exception from its map.
 199 Node* GraphKit::saved_ex_oop(SafePointNode* ex_map) {
 200   return common_saved_ex_oop(ex_map, false);
 201 }
 202 
 203 //--------------------------clear_saved_ex_oop---------------------------------
 204 // Erase a previously saved exception from its map.
 205 Node* GraphKit::clear_saved_ex_oop(SafePointNode* ex_map) {
 206   return common_saved_ex_oop(ex_map, true);
 207 }
 208 
 209 #ifdef ASSERT
 210 //---------------------------has_saved_ex_oop----------------------------------
 211 // Erase a previously saved exception from its map.
 212 bool GraphKit::has_saved_ex_oop(SafePointNode* ex_map) {
 213   return ex_map->req() == ex_map->jvms()->endoff()+1;
 214 }
 215 #endif
 216 
 217 //-------------------------make_exception_state--------------------------------
 218 // Turn the current JVM state into an exception state, appending the ex_oop.
 219 SafePointNode* GraphKit::make_exception_state(Node* ex_oop) {
 220   sync_jvms();
 221   SafePointNode* ex_map = stop();  // do not manipulate this map any more
 222   set_saved_ex_oop(ex_map, ex_oop);
 223   return ex_map;
 224 }
 225 
 226 
 227 //--------------------------add_exception_state--------------------------------
 228 // Add an exception to my list of exceptions.
 229 void GraphKit::add_exception_state(SafePointNode* ex_map) {
 230   if (ex_map == NULL || ex_map->control() == top()) {
 231     return;
 232   }
 233 #ifdef ASSERT
 234   verify_exception_state(ex_map);
 235   if (has_exceptions()) {
 236     assert(ex_map->jvms()->same_calls_as(_exceptions->jvms()), "all collected exceptions must come from the same place");
 237   }
 238 #endif
 239 
 240   // If there is already an exception of exactly this type, merge with it.
 241   // In particular, null-checks and other low-level exceptions common up here.
 242   Node*       ex_oop  = saved_ex_oop(ex_map);
 243   const Type* ex_type = _gvn.type(ex_oop);
 244   if (ex_oop == top()) {
 245     // No action needed.
 246     return;
 247   }
 248   assert(ex_type->isa_instptr(), "exception must be an instance");
 249   for (SafePointNode* e2 = _exceptions; e2 != NULL; e2 = e2->next_exception()) {
 250     const Type* ex_type2 = _gvn.type(saved_ex_oop(e2));
 251     // We check sp also because call bytecodes can generate exceptions
 252     // both before and after arguments are popped!
 253     if (ex_type2 == ex_type
 254         && e2->_jvms->sp() == ex_map->_jvms->sp()) {
 255       combine_exception_states(ex_map, e2);
 256       return;
 257     }
 258   }
 259 
 260   // No pre-existing exception of the same type.  Chain it on the list.
 261   push_exception_state(ex_map);
 262 }
 263 
 264 //-----------------------add_exception_states_from-----------------------------
 265 void GraphKit::add_exception_states_from(JVMState* jvms) {
 266   SafePointNode* ex_map = jvms->map()->next_exception();
 267   if (ex_map != NULL) {
 268     jvms->map()->set_next_exception(NULL);
 269     for (SafePointNode* next_map; ex_map != NULL; ex_map = next_map) {
 270       next_map = ex_map->next_exception();
 271       ex_map->set_next_exception(NULL);
 272       add_exception_state(ex_map);
 273     }
 274   }
 275 }
 276 
 277 //-----------------------transfer_exceptions_into_jvms-------------------------
 278 JVMState* GraphKit::transfer_exceptions_into_jvms() {
 279   if (map() == NULL) {
 280     // We need a JVMS to carry the exceptions, but the map has gone away.
 281     // Create a scratch JVMS, cloned from any of the exception states...
 282     if (has_exceptions()) {
 283       _map = _exceptions;
 284       _map = clone_map();
 285       _map->set_next_exception(NULL);
 286       clear_saved_ex_oop(_map);
 287       debug_only(verify_map());
 288     } else {
 289       // ...or created from scratch
 290       JVMState* jvms = new (C) JVMState(_method, NULL);
 291       jvms->set_bci(_bci);
 292       jvms->set_sp(_sp);
 293       jvms->set_map(new (C) SafePointNode(TypeFunc::Parms, jvms));
 294       set_jvms(jvms);
 295       for (uint i = 0; i < map()->req(); i++)  map()->init_req(i, top());
 296       set_all_memory(top());
 297       while (map()->req() < jvms->endoff())  map()->add_req(top());
 298     }
 299     // (This is a kludge, in case you didn't notice.)
 300     set_control(top());
 301   }
 302   JVMState* jvms = sync_jvms();
 303   assert(!jvms->map()->has_exceptions(), "no exceptions on this map yet");
 304   jvms->map()->set_next_exception(_exceptions);
 305   _exceptions = NULL;   // done with this set of exceptions
 306   return jvms;
 307 }
 308 
 309 static inline void add_n_reqs(Node* dstphi, Node* srcphi) {
 310   assert(is_hidden_merge(dstphi), "must be a special merge node");
 311   assert(is_hidden_merge(srcphi), "must be a special merge node");
 312   uint limit = srcphi->req();
 313   for (uint i = PhiNode::Input; i < limit; i++) {
 314     dstphi->add_req(srcphi->in(i));
 315   }
 316 }
 317 static inline void add_one_req(Node* dstphi, Node* src) {
 318   assert(is_hidden_merge(dstphi), "must be a special merge node");
 319   assert(!is_hidden_merge(src), "must not be a special merge node");
 320   dstphi->add_req(src);
 321 }
 322 
 323 //-----------------------combine_exception_states------------------------------
 324 // This helper function combines exception states by building phis on a
 325 // specially marked state-merging region.  These regions and phis are
 326 // untransformed, and can build up gradually.  The region is marked by
 327 // having a control input of its exception map, rather than NULL.  Such
 328 // regions do not appear except in this function, and in use_exception_state.
 329 void GraphKit::combine_exception_states(SafePointNode* ex_map, SafePointNode* phi_map) {
 330   if (failing())  return;  // dying anyway...
 331   JVMState* ex_jvms = ex_map->_jvms;
 332   assert(ex_jvms->same_calls_as(phi_map->_jvms), "consistent call chains");
 333   assert(ex_jvms->stkoff() == phi_map->_jvms->stkoff(), "matching locals");
 334   assert(ex_jvms->sp() == phi_map->_jvms->sp(), "matching stack sizes");
 335   assert(ex_jvms->monoff() == phi_map->_jvms->monoff(), "matching JVMS");
 336   assert(ex_jvms->scloff() == phi_map->_jvms->scloff(), "matching scalar replaced objects");
 337   assert(ex_map->req() == phi_map->req(), "matching maps");
 338   uint tos = ex_jvms->stkoff() + ex_jvms->sp();
 339   Node*         hidden_merge_mark = root();
 340   Node*         region  = phi_map->control();
 341   MergeMemNode* phi_mem = phi_map->merged_memory();
 342   MergeMemNode* ex_mem  = ex_map->merged_memory();
 343   if (region->in(0) != hidden_merge_mark) {
 344     // The control input is not (yet) a specially-marked region in phi_map.
 345     // Make it so, and build some phis.
 346     region = new (C) RegionNode(2);
 347     _gvn.set_type(region, Type::CONTROL);
 348     region->set_req(0, hidden_merge_mark);  // marks an internal ex-state
 349     region->init_req(1, phi_map->control());
 350     phi_map->set_control(region);
 351     Node* io_phi = PhiNode::make(region, phi_map->i_o(), Type::ABIO);
 352     record_for_igvn(io_phi);
 353     _gvn.set_type(io_phi, Type::ABIO);
 354     phi_map->set_i_o(io_phi);
 355     for (MergeMemStream mms(phi_mem); mms.next_non_empty(); ) {
 356       Node* m = mms.memory();
 357       Node* m_phi = PhiNode::make(region, m, Type::MEMORY, mms.adr_type(C));
 358       record_for_igvn(m_phi);
 359       _gvn.set_type(m_phi, Type::MEMORY);
 360       mms.set_memory(m_phi);
 361     }
 362   }
 363 
 364   // Either or both of phi_map and ex_map might already be converted into phis.
 365   Node* ex_control = ex_map->control();
 366   // if there is special marking on ex_map also, we add multiple edges from src
 367   bool add_multiple = (ex_control->in(0) == hidden_merge_mark);
 368   // how wide was the destination phi_map, originally?
 369   uint orig_width = region->req();
 370 
 371   if (add_multiple) {
 372     add_n_reqs(region, ex_control);
 373     add_n_reqs(phi_map->i_o(), ex_map->i_o());
 374   } else {
 375     // ex_map has no merges, so we just add single edges everywhere
 376     add_one_req(region, ex_control);
 377     add_one_req(phi_map->i_o(), ex_map->i_o());
 378   }
 379   for (MergeMemStream mms(phi_mem, ex_mem); mms.next_non_empty2(); ) {
 380     if (mms.is_empty()) {
 381       // get a copy of the base memory, and patch some inputs into it
 382       const TypePtr* adr_type = mms.adr_type(C);
 383       Node* phi = mms.force_memory()->as_Phi()->slice_memory(adr_type);
 384       assert(phi->as_Phi()->region() == mms.base_memory()->in(0), "");
 385       mms.set_memory(phi);
 386       // Prepare to append interesting stuff onto the newly sliced phi:
 387       while (phi->req() > orig_width)  phi->del_req(phi->req()-1);
 388     }
 389     // Append stuff from ex_map:
 390     if (add_multiple) {
 391       add_n_reqs(mms.memory(), mms.memory2());
 392     } else {
 393       add_one_req(mms.memory(), mms.memory2());
 394     }
 395   }
 396   uint limit = ex_map->req();
 397   for (uint i = TypeFunc::Parms; i < limit; i++) {
 398     // Skip everything in the JVMS after tos.  (The ex_oop follows.)
 399     if (i == tos)  i = ex_jvms->monoff();
 400     Node* src = ex_map->in(i);
 401     Node* dst = phi_map->in(i);
 402     if (src != dst) {
 403       PhiNode* phi;
 404       if (dst->in(0) != region) {
 405         dst = phi = PhiNode::make(region, dst, _gvn.type(dst));
 406         record_for_igvn(phi);
 407         _gvn.set_type(phi, phi->type());
 408         phi_map->set_req(i, dst);
 409         // Prepare to append interesting stuff onto the new phi:
 410         while (dst->req() > orig_width)  dst->del_req(dst->req()-1);
 411       } else {
 412         assert(dst->is_Phi(), "nobody else uses a hidden region");
 413         phi = dst->as_Phi();
 414       }
 415       if (add_multiple && src->in(0) == ex_control) {
 416         // Both are phis.
 417         add_n_reqs(dst, src);
 418       } else {
 419         while (dst->req() < region->req())  add_one_req(dst, src);
 420       }
 421       const Type* srctype = _gvn.type(src);
 422       if (phi->type() != srctype) {
 423         const Type* dsttype = phi->type()->meet_speculative(srctype);
 424         if (phi->type() != dsttype) {
 425           phi->set_type(dsttype);
 426           _gvn.set_type(phi, dsttype);
 427         }
 428       }
 429     }
 430   }
 431 }
 432 
 433 //--------------------------use_exception_state--------------------------------
 434 Node* GraphKit::use_exception_state(SafePointNode* phi_map) {
 435   if (failing()) { stop(); return top(); }
 436   Node* region = phi_map->control();
 437   Node* hidden_merge_mark = root();
 438   assert(phi_map->jvms()->map() == phi_map, "sanity: 1-1 relation");
 439   Node* ex_oop = clear_saved_ex_oop(phi_map);
 440   if (region->in(0) == hidden_merge_mark) {
 441     // Special marking for internal ex-states.  Process the phis now.
 442     region->set_req(0, region);  // now it's an ordinary region
 443     set_jvms(phi_map->jvms());   // ...so now we can use it as a map
 444     // Note: Setting the jvms also sets the bci and sp.
 445     set_control(_gvn.transform(region));
 446     uint tos = jvms()->stkoff() + sp();
 447     for (uint i = 1; i < tos; i++) {
 448       Node* x = phi_map->in(i);
 449       if (x->in(0) == region) {
 450         assert(x->is_Phi(), "expected a special phi");
 451         phi_map->set_req(i, _gvn.transform(x));
 452       }
 453     }
 454     for (MergeMemStream mms(merged_memory()); mms.next_non_empty(); ) {
 455       Node* x = mms.memory();
 456       if (x->in(0) == region) {
 457         assert(x->is_Phi(), "nobody else uses a hidden region");
 458         mms.set_memory(_gvn.transform(x));
 459       }
 460     }
 461     if (ex_oop->in(0) == region) {
 462       assert(ex_oop->is_Phi(), "expected a special phi");
 463       ex_oop = _gvn.transform(ex_oop);
 464     }
 465   } else {
 466     set_jvms(phi_map->jvms());
 467   }
 468 
 469   assert(!is_hidden_merge(phi_map->control()), "hidden ex. states cleared");
 470   assert(!is_hidden_merge(phi_map->i_o()), "hidden ex. states cleared");
 471   return ex_oop;
 472 }
 473 
 474 //---------------------------------java_bc-------------------------------------
 475 Bytecodes::Code GraphKit::java_bc() const {
 476   ciMethod* method = this->method();
 477   int       bci    = this->bci();
 478   if (method != NULL && bci != InvocationEntryBci)
 479     return method->java_code_at_bci(bci);
 480   else
 481     return Bytecodes::_illegal;
 482 }
 483 
 484 void GraphKit::uncommon_trap_if_should_post_on_exceptions(Deoptimization::DeoptReason reason,
 485                                                           bool must_throw) {
 486     // if the exception capability is set, then we will generate code
 487     // to check the JavaThread.should_post_on_exceptions flag to see
 488     // if we actually need to report exception events (for this
 489     // thread).  If we don't need to report exception events, we will
 490     // take the normal fast path provided by add_exception_events.  If
 491     // exception event reporting is enabled for this thread, we will
 492     // take the uncommon_trap in the BuildCutout below.
 493 
 494     // first must access the should_post_on_exceptions_flag in this thread's JavaThread
 495     Node* jthread = _gvn.transform(new (C) ThreadLocalNode());
 496     Node* adr = basic_plus_adr(top(), jthread, in_bytes(JavaThread::should_post_on_exceptions_flag_offset()));
 497     Node* should_post_flag = make_load(control(), adr, TypeInt::INT, T_INT, Compile::AliasIdxRaw, MemNode::unordered);
 498 
 499     // Test the should_post_on_exceptions_flag vs. 0
 500     Node* chk = _gvn.transform( new (C) CmpINode(should_post_flag, intcon(0)) );
 501     Node* tst = _gvn.transform( new (C) BoolNode(chk, BoolTest::eq) );
 502 
 503     // Branch to slow_path if should_post_on_exceptions_flag was true
 504     { BuildCutout unless(this, tst, PROB_MAX);
 505       // Do not try anything fancy if we're notifying the VM on every throw.
 506       // Cf. case Bytecodes::_athrow in parse2.cpp.
 507       uncommon_trap(reason, Deoptimization::Action_none,
 508                     (ciKlass*)NULL, (char*)NULL, must_throw);
 509     }
 510 
 511 }
 512 
 513 //------------------------------builtin_throw----------------------------------
 514 void GraphKit::builtin_throw(Deoptimization::DeoptReason reason, Node* arg) {
 515   bool must_throw = true;
 516 
 517   if (env()->jvmti_can_post_on_exceptions()) {
 518     // check if we must post exception events, take uncommon trap if so
 519     uncommon_trap_if_should_post_on_exceptions(reason, must_throw);
 520     // here if should_post_on_exceptions is false
 521     // continue on with the normal codegen
 522   }
 523 
 524   // If this particular condition has not yet happened at this
 525   // bytecode, then use the uncommon trap mechanism, and allow for
 526   // a future recompilation if several traps occur here.
 527   // If the throw is hot, try to use a more complicated inline mechanism
 528   // which keeps execution inside the compiled code.
 529   bool treat_throw_as_hot = false;
 530   ciMethodData* md = method()->method_data();
 531 
 532   if (ProfileTraps) {
 533     if (too_many_traps(reason)) {
 534       treat_throw_as_hot = true;
 535     }
 536     // (If there is no MDO at all, assume it is early in
 537     // execution, and that any deopts are part of the
 538     // startup transient, and don't need to be remembered.)
 539 
 540     // Also, if there is a local exception handler, treat all throws
 541     // as hot if there has been at least one in this method.
 542     if (C->trap_count(reason) != 0
 543         && method()->method_data()->trap_count(reason) != 0
 544         && has_ex_handler()) {
 545         treat_throw_as_hot = true;
 546     }
 547   }
 548 
 549   // If this throw happens frequently, an uncommon trap might cause
 550   // a performance pothole.  If there is a local exception handler,
 551   // and if this particular bytecode appears to be deoptimizing often,
 552   // let us handle the throw inline, with a preconstructed instance.
 553   // Note:   If the deopt count has blown up, the uncommon trap
 554   // runtime is going to flush this nmethod, not matter what.
 555   if (treat_throw_as_hot
 556       && (!StackTraceInThrowable || OmitStackTraceInFastThrow)) {
 557     // If the throw is local, we use a pre-existing instance and
 558     // punt on the backtrace.  This would lead to a missing backtrace
 559     // (a repeat of 4292742) if the backtrace object is ever asked
 560     // for its backtrace.
 561     // Fixing this remaining case of 4292742 requires some flavor of
 562     // escape analysis.  Leave that for the future.
 563     ciInstance* ex_obj = NULL;
 564     switch (reason) {
 565     case Deoptimization::Reason_null_check:
 566       ex_obj = env()->NullPointerException_instance();
 567       break;
 568     case Deoptimization::Reason_div0_check:
 569       ex_obj = env()->ArithmeticException_instance();
 570       break;
 571     case Deoptimization::Reason_range_check:
 572       ex_obj = env()->ArrayIndexOutOfBoundsException_instance();
 573       break;
 574     case Deoptimization::Reason_class_check:
 575       if (java_bc() == Bytecodes::_aastore) {
 576         ex_obj = env()->ArrayStoreException_instance();
 577       } else {
 578         ex_obj = env()->ClassCastException_instance();
 579       }
 580       break;
 581     }
 582     if (failing()) { stop(); return; }  // exception allocation might fail
 583     if (ex_obj != NULL) {
 584       // Cheat with a preallocated exception object.
 585       if (C->log() != NULL)
 586         C->log()->elem("hot_throw preallocated='1' reason='%s'",
 587                        Deoptimization::trap_reason_name(reason));
 588       const TypeInstPtr* ex_con  = TypeInstPtr::make(ex_obj);
 589       Node*              ex_node = _gvn.transform( ConNode::make(C, ex_con) );
 590 
 591       // Clear the detail message of the preallocated exception object.
 592       // Weblogic sometimes mutates the detail message of exceptions
 593       // using reflection.
 594       int offset = java_lang_Throwable::get_detailMessage_offset();
 595       const TypePtr* adr_typ = ex_con->add_offset(offset);
 596 
 597       Node *adr = basic_plus_adr(ex_node, ex_node, offset);
 598       const TypeOopPtr* val_type = TypeOopPtr::make_from_klass(env()->String_klass());
 599       // Conservatively release stores of object references.
 600       Node *store = store_oop_to_object(control(), ex_node, adr, adr_typ, null(), val_type, T_OBJECT, MemNode::release);
 601 
 602       add_exception_state(make_exception_state(ex_node));
 603       return;
 604     }
 605   }
 606 
 607   // %%% Maybe add entry to OptoRuntime which directly throws the exc.?
 608   // It won't be much cheaper than bailing to the interp., since we'll
 609   // have to pass up all the debug-info, and the runtime will have to
 610   // create the stack trace.
 611 
 612   // Usual case:  Bail to interpreter.
 613   // Reserve the right to recompile if we haven't seen anything yet.
 614 
 615   assert(!Deoptimization::reason_is_speculate(reason), "unsupported");
 616   Deoptimization::DeoptAction action = Deoptimization::Action_maybe_recompile;
 617   if (treat_throw_as_hot
 618       && (method()->method_data()->trap_recompiled_at(bci(), NULL)
 619           || C->too_many_traps(reason))) {
 620     // We cannot afford to take more traps here.  Suffer in the interpreter.
 621     if (C->log() != NULL)
 622       C->log()->elem("hot_throw preallocated='0' reason='%s' mcount='%d'",
 623                      Deoptimization::trap_reason_name(reason),
 624                      C->trap_count(reason));
 625     action = Deoptimization::Action_none;
 626   }
 627 
 628   // "must_throw" prunes the JVM state to include only the stack, if there
 629   // are no local exception handlers.  This should cut down on register
 630   // allocation time and code size, by drastically reducing the number
 631   // of in-edges on the call to the uncommon trap.
 632 
 633   uncommon_trap(reason, action, (ciKlass*)NULL, (char*)NULL, must_throw);
 634 }
 635 
 636 
 637 //----------------------------PreserveJVMState---------------------------------
 638 PreserveJVMState::PreserveJVMState(GraphKit* kit, bool clone_map) {
 639   debug_only(kit->verify_map());
 640   _kit    = kit;
 641   _map    = kit->map();   // preserve the map
 642   _sp     = kit->sp();
 643   kit->set_map(clone_map ? kit->clone_map() : NULL);
 644   Compile::current()->inc_preserve_jvm_state();
 645 #ifdef ASSERT
 646   _bci    = kit->bci();
 647   Parse* parser = kit->is_Parse();
 648   int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo();
 649   _block  = block;
 650 #endif
 651 }
 652 PreserveJVMState::~PreserveJVMState() {
 653   GraphKit* kit = _kit;
 654 #ifdef ASSERT
 655   assert(kit->bci() == _bci, "bci must not shift");
 656   Parse* parser = kit->is_Parse();
 657   int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo();
 658   assert(block == _block,    "block must not shift");
 659 #endif
 660   kit->set_map(_map);
 661   kit->set_sp(_sp);
 662   Compile::current()->dec_preserve_jvm_state();
 663 }
 664 
 665 
 666 //-----------------------------BuildCutout-------------------------------------
 667 BuildCutout::BuildCutout(GraphKit* kit, Node* p, float prob, float cnt)
 668   : PreserveJVMState(kit)
 669 {
 670   assert(p->is_Con() || p->is_Bool(), "test must be a bool");
 671   SafePointNode* outer_map = _map;   // preserved map is caller's
 672   SafePointNode* inner_map = kit->map();
 673   IfNode* iff = kit->create_and_map_if(outer_map->control(), p, prob, cnt);
 674   outer_map->set_control(kit->gvn().transform( new (kit->C) IfTrueNode(iff) ));
 675   inner_map->set_control(kit->gvn().transform( new (kit->C) IfFalseNode(iff) ));
 676 }
 677 BuildCutout::~BuildCutout() {
 678   GraphKit* kit = _kit;
 679   assert(kit->stopped(), "cutout code must stop, throw, return, etc.");
 680 }
 681 
 682 //---------------------------PreserveReexecuteState----------------------------
 683 PreserveReexecuteState::PreserveReexecuteState(GraphKit* kit) {
 684   assert(!kit->stopped(), "must call stopped() before");
 685   _kit    =    kit;
 686   _sp     =    kit->sp();
 687   _reexecute = kit->jvms()->_reexecute;
 688 }
 689 PreserveReexecuteState::~PreserveReexecuteState() {
 690   if (_kit->stopped()) return;
 691   _kit->jvms()->_reexecute = _reexecute;
 692   _kit->set_sp(_sp);
 693 }
 694 
 695 //------------------------------clone_map--------------------------------------
 696 // Implementation of PreserveJVMState
 697 //
 698 // Only clone_map(...) here. If this function is only used in the
 699 // PreserveJVMState class we may want to get rid of this extra
 700 // function eventually and do it all there.
 701 
 702 SafePointNode* GraphKit::clone_map() {
 703   if (map() == NULL)  return NULL;
 704 
 705   // Clone the memory edge first
 706   Node* mem = MergeMemNode::make(C, map()->memory());
 707   gvn().set_type_bottom(mem);
 708 
 709   SafePointNode *clonemap = (SafePointNode*)map()->clone();
 710   JVMState* jvms = this->jvms();
 711   JVMState* clonejvms = jvms->clone_shallow(C);
 712   clonemap->set_memory(mem);
 713   clonemap->set_jvms(clonejvms);
 714   clonejvms->set_map(clonemap);
 715   record_for_igvn(clonemap);
 716   gvn().set_type_bottom(clonemap);
 717   return clonemap;
 718 }
 719 
 720 
 721 //-----------------------------set_map_clone-----------------------------------
 722 void GraphKit::set_map_clone(SafePointNode* m) {
 723   _map = m;
 724   _map = clone_map();
 725   _map->set_next_exception(NULL);
 726   debug_only(verify_map());
 727 }
 728 
 729 
 730 //----------------------------kill_dead_locals---------------------------------
 731 // Detect any locals which are known to be dead, and force them to top.
 732 void GraphKit::kill_dead_locals() {
 733   // Consult the liveness information for the locals.  If any
 734   // of them are unused, then they can be replaced by top().  This
 735   // should help register allocation time and cut down on the size
 736   // of the deoptimization information.
 737 
 738   // This call is made from many of the bytecode handling
 739   // subroutines called from the Big Switch in do_one_bytecode.
 740   // Every bytecode which might include a slow path is responsible
 741   // for killing its dead locals.  The more consistent we
 742   // are about killing deads, the fewer useless phis will be
 743   // constructed for them at various merge points.
 744 
 745   // bci can be -1 (InvocationEntryBci).  We return the entry
 746   // liveness for the method.
 747 
 748   if (method() == NULL || method()->code_size() == 0) {
 749     // We are building a graph for a call to a native method.
 750     // All locals are live.
 751     return;
 752   }
 753 
 754   ResourceMark rm;
 755 
 756   // Consult the liveness information for the locals.  If any
 757   // of them are unused, then they can be replaced by top().  This
 758   // should help register allocation time and cut down on the size
 759   // of the deoptimization information.
 760   MethodLivenessResult live_locals = method()->liveness_at_bci(bci());
 761 
 762   int len = (int)live_locals.size();
 763   assert(len <= jvms()->loc_size(), "too many live locals");
 764   for (int local = 0; local < len; local++) {
 765     if (!live_locals.at(local)) {
 766       set_local(local, top());
 767     }
 768   }
 769 }
 770 
 771 #ifdef ASSERT
 772 //-------------------------dead_locals_are_killed------------------------------
 773 // Return true if all dead locals are set to top in the map.
 774 // Used to assert "clean" debug info at various points.
 775 bool GraphKit::dead_locals_are_killed() {
 776   if (method() == NULL || method()->code_size() == 0) {
 777     // No locals need to be dead, so all is as it should be.
 778     return true;
 779   }
 780 
 781   // Make sure somebody called kill_dead_locals upstream.
 782   ResourceMark rm;
 783   for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) {
 784     if (jvms->loc_size() == 0)  continue;  // no locals to consult
 785     SafePointNode* map = jvms->map();
 786     ciMethod* method = jvms->method();
 787     int       bci    = jvms->bci();
 788     if (jvms == this->jvms()) {
 789       bci = this->bci();  // it might not yet be synched
 790     }
 791     MethodLivenessResult live_locals = method->liveness_at_bci(bci);
 792     int len = (int)live_locals.size();
 793     if (!live_locals.is_valid() || len == 0)
 794       // This method is trivial, or is poisoned by a breakpoint.
 795       return true;
 796     assert(len == jvms->loc_size(), "live map consistent with locals map");
 797     for (int local = 0; local < len; local++) {
 798       if (!live_locals.at(local) && map->local(jvms, local) != top()) {
 799         if (PrintMiscellaneous && (Verbose || WizardMode)) {
 800           tty->print_cr("Zombie local %d: ", local);
 801           jvms->dump();
 802         }
 803         return false;
 804       }
 805     }
 806   }
 807   return true;
 808 }
 809 
 810 #endif //ASSERT
 811 
 812 // Helper function for enforcing certain bytecodes to reexecute if
 813 // deoptimization happens
 814 static bool should_reexecute_implied_by_bytecode(JVMState *jvms, bool is_anewarray) {
 815   ciMethod* cur_method = jvms->method();
 816   int       cur_bci   = jvms->bci();
 817   if (cur_method != NULL && cur_bci != InvocationEntryBci) {
 818     Bytecodes::Code code = cur_method->java_code_at_bci(cur_bci);
 819     return Interpreter::bytecode_should_reexecute(code) ||
 820            is_anewarray && code == Bytecodes::_multianewarray;
 821     // Reexecute _multianewarray bytecode which was replaced with
 822     // sequence of [a]newarray. See Parse::do_multianewarray().
 823     //
 824     // Note: interpreter should not have it set since this optimization
 825     // is limited by dimensions and guarded by flag so in some cases
 826     // multianewarray() runtime calls will be generated and
 827     // the bytecode should not be reexecutes (stack will not be reset).
 828   } else
 829     return false;
 830 }
 831 
 832 // Helper function for adding JVMState and debug information to node
 833 void GraphKit::add_safepoint_edges(SafePointNode* call, bool must_throw) {
 834   // Add the safepoint edges to the call (or other safepoint).
 835 
 836   // Make sure dead locals are set to top.  This
 837   // should help register allocation time and cut down on the size
 838   // of the deoptimization information.
 839   assert(dead_locals_are_killed(), "garbage in debug info before safepoint");
 840 
 841   // Walk the inline list to fill in the correct set of JVMState's
 842   // Also fill in the associated edges for each JVMState.
 843 
 844   // If the bytecode needs to be reexecuted we need to put
 845   // the arguments back on the stack.
 846   const bool should_reexecute = jvms()->should_reexecute();
 847   JVMState* youngest_jvms = should_reexecute ? sync_jvms_for_reexecute() : sync_jvms();
 848 
 849   // NOTE: set_bci (called from sync_jvms) might reset the reexecute bit to
 850   // undefined if the bci is different.  This is normal for Parse but it
 851   // should not happen for LibraryCallKit because only one bci is processed.
 852   assert(!is_LibraryCallKit() || (jvms()->should_reexecute() == should_reexecute),
 853          "in LibraryCallKit the reexecute bit should not change");
 854 
 855   // If we are guaranteed to throw, we can prune everything but the
 856   // input to the current bytecode.
 857   bool can_prune_locals = false;
 858   uint stack_slots_not_pruned = 0;
 859   int inputs = 0, depth = 0;
 860   if (must_throw) {
 861     assert(method() == youngest_jvms->method(), "sanity");
 862     if (compute_stack_effects(inputs, depth)) {
 863       can_prune_locals = true;
 864       stack_slots_not_pruned = inputs;
 865     }
 866   }
 867 
 868   if (env()->should_retain_local_variables()) {
 869     // At any safepoint, this method can get breakpointed, which would
 870     // then require an immediate deoptimization.
 871     can_prune_locals = false;  // do not prune locals
 872     stack_slots_not_pruned = 0;
 873   }
 874 
 875   // do not scribble on the input jvms
 876   JVMState* out_jvms = youngest_jvms->clone_deep(C);
 877   call->set_jvms(out_jvms); // Start jvms list for call node
 878 
 879   // For a known set of bytecodes, the interpreter should reexecute them if
 880   // deoptimization happens. We set the reexecute state for them here
 881   if (out_jvms->is_reexecute_undefined() && //don't change if already specified
 882       should_reexecute_implied_by_bytecode(out_jvms, call->is_AllocateArray())) {
 883     out_jvms->set_should_reexecute(true); //NOTE: youngest_jvms not changed
 884   }
 885 
 886   // Presize the call:
 887   DEBUG_ONLY(uint non_debug_edges = call->req());
 888   call->add_req_batch(top(), youngest_jvms->debug_depth());
 889   assert(call->req() == non_debug_edges + youngest_jvms->debug_depth(), "");
 890 
 891   // Set up edges so that the call looks like this:
 892   //  Call [state:] ctl io mem fptr retadr
 893   //       [parms:] parm0 ... parmN
 894   //       [root:]  loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN
 895   //    [...mid:]   loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN [...]
 896   //       [young:] loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN
 897   // Note that caller debug info precedes callee debug info.
 898 
 899   // Fill pointer walks backwards from "young:" to "root:" in the diagram above:
 900   uint debug_ptr = call->req();
 901 
 902   // Loop over the map input edges associated with jvms, add them
 903   // to the call node, & reset all offsets to match call node array.
 904   for (JVMState* in_jvms = youngest_jvms; in_jvms != NULL; ) {
 905     uint debug_end   = debug_ptr;
 906     uint debug_start = debug_ptr - in_jvms->debug_size();
 907     debug_ptr = debug_start;  // back up the ptr
 908 
 909     uint p = debug_start;  // walks forward in [debug_start, debug_end)
 910     uint j, k, l;
 911     SafePointNode* in_map = in_jvms->map();
 912     out_jvms->set_map(call);
 913 
 914     if (can_prune_locals) {
 915       assert(in_jvms->method() == out_jvms->method(), "sanity");
 916       // If the current throw can reach an exception handler in this JVMS,
 917       // then we must keep everything live that can reach that handler.
 918       // As a quick and dirty approximation, we look for any handlers at all.
 919       if (in_jvms->method()->has_exception_handlers()) {
 920         can_prune_locals = false;
 921       }
 922     }
 923 
 924     // Add the Locals
 925     k = in_jvms->locoff();
 926     l = in_jvms->loc_size();
 927     out_jvms->set_locoff(p);
 928     if (!can_prune_locals) {
 929       for (j = 0; j < l; j++)
 930         call->set_req(p++, in_map->in(k+j));
 931     } else {
 932       p += l;  // already set to top above by add_req_batch
 933     }
 934 
 935     // Add the Expression Stack
 936     k = in_jvms->stkoff();
 937     l = in_jvms->sp();
 938     out_jvms->set_stkoff(p);
 939     if (!can_prune_locals) {
 940       for (j = 0; j < l; j++)
 941         call->set_req(p++, in_map->in(k+j));
 942     } else if (can_prune_locals && stack_slots_not_pruned != 0) {
 943       // Divide stack into {S0,...,S1}, where S0 is set to top.
 944       uint s1 = stack_slots_not_pruned;
 945       stack_slots_not_pruned = 0;  // for next iteration
 946       if (s1 > l)  s1 = l;
 947       uint s0 = l - s1;
 948       p += s0;  // skip the tops preinstalled by add_req_batch
 949       for (j = s0; j < l; j++)
 950         call->set_req(p++, in_map->in(k+j));
 951     } else {
 952       p += l;  // already set to top above by add_req_batch
 953     }
 954 
 955     // Add the Monitors
 956     k = in_jvms->monoff();
 957     l = in_jvms->mon_size();
 958     out_jvms->set_monoff(p);
 959     for (j = 0; j < l; j++)
 960       call->set_req(p++, in_map->in(k+j));
 961 
 962     // Copy any scalar object fields.
 963     k = in_jvms->scloff();
 964     l = in_jvms->scl_size();
 965     out_jvms->set_scloff(p);
 966     for (j = 0; j < l; j++)
 967       call->set_req(p++, in_map->in(k+j));
 968 
 969     // Finish the new jvms.
 970     out_jvms->set_endoff(p);
 971 
 972     assert(out_jvms->endoff()     == debug_end,             "fill ptr must match");
 973     assert(out_jvms->depth()      == in_jvms->depth(),      "depth must match");
 974     assert(out_jvms->loc_size()   == in_jvms->loc_size(),   "size must match");
 975     assert(out_jvms->mon_size()   == in_jvms->mon_size(),   "size must match");
 976     assert(out_jvms->scl_size()   == in_jvms->scl_size(),   "size must match");
 977     assert(out_jvms->debug_size() == in_jvms->debug_size(), "size must match");
 978 
 979     // Update the two tail pointers in parallel.
 980     out_jvms = out_jvms->caller();
 981     in_jvms  = in_jvms->caller();
 982   }
 983 
 984   assert(debug_ptr == non_debug_edges, "debug info must fit exactly");
 985 
 986   // Test the correctness of JVMState::debug_xxx accessors:
 987   assert(call->jvms()->debug_start() == non_debug_edges, "");
 988   assert(call->jvms()->debug_end()   == call->req(), "");
 989   assert(call->jvms()->debug_depth() == call->req() - non_debug_edges, "");
 990 }
 991 
 992 bool GraphKit::compute_stack_effects(int& inputs, int& depth) {
 993   Bytecodes::Code code = java_bc();
 994   if (code == Bytecodes::_wide) {
 995     code = method()->java_code_at_bci(bci() + 1);
 996   }
 997 
 998   BasicType rtype = T_ILLEGAL;
 999   int       rsize = 0;
1000 
1001   if (code != Bytecodes::_illegal) {
1002     depth = Bytecodes::depth(code); // checkcast=0, athrow=-1
1003     rtype = Bytecodes::result_type(code); // checkcast=P, athrow=V
1004     if (rtype < T_CONFLICT)
1005       rsize = type2size[rtype];
1006   }
1007 
1008   switch (code) {
1009   case Bytecodes::_illegal:
1010     return false;
1011 
1012   case Bytecodes::_ldc:
1013   case Bytecodes::_ldc_w:
1014   case Bytecodes::_ldc2_w:
1015     inputs = 0;
1016     break;
1017 
1018   case Bytecodes::_dup:         inputs = 1;  break;
1019   case Bytecodes::_dup_x1:      inputs = 2;  break;
1020   case Bytecodes::_dup_x2:      inputs = 3;  break;
1021   case Bytecodes::_dup2:        inputs = 2;  break;
1022   case Bytecodes::_dup2_x1:     inputs = 3;  break;
1023   case Bytecodes::_dup2_x2:     inputs = 4;  break;
1024   case Bytecodes::_swap:        inputs = 2;  break;
1025   case Bytecodes::_arraylength: inputs = 1;  break;
1026 
1027   case Bytecodes::_getstatic:
1028   case Bytecodes::_putstatic:
1029   case Bytecodes::_getfield:
1030   case Bytecodes::_putfield:
1031     {
1032       bool ignored_will_link;
1033       ciField* field = method()->get_field_at_bci(bci(), ignored_will_link);
1034       int      size  = field->type()->size();
1035       bool is_get = (depth >= 0), is_static = (depth & 1);
1036       inputs = (is_static ? 0 : 1);
1037       if (is_get) {
1038         depth = size - inputs;
1039       } else {
1040         inputs += size;        // putxxx pops the value from the stack
1041         depth = - inputs;
1042       }
1043     }
1044     break;
1045 
1046   case Bytecodes::_invokevirtual:
1047   case Bytecodes::_invokespecial:
1048   case Bytecodes::_invokestatic:
1049   case Bytecodes::_invokedynamic:
1050   case Bytecodes::_invokeinterface:
1051     {
1052       bool ignored_will_link;
1053       ciSignature* declared_signature = NULL;
1054       ciMethod* ignored_callee = method()->get_method_at_bci(bci(), ignored_will_link, &declared_signature);
1055       assert(declared_signature != NULL, "cannot be null");
1056       inputs   = declared_signature->arg_size_for_bc(code);
1057       int size = declared_signature->return_type()->size();
1058       depth = size - inputs;
1059     }
1060     break;
1061 
1062   case Bytecodes::_multianewarray:
1063     {
1064       ciBytecodeStream iter(method());
1065       iter.reset_to_bci(bci());
1066       iter.next();
1067       inputs = iter.get_dimensions();
1068       assert(rsize == 1, "");
1069       depth = rsize - inputs;
1070     }
1071     break;
1072 
1073   case Bytecodes::_ireturn:
1074   case Bytecodes::_lreturn:
1075   case Bytecodes::_freturn:
1076   case Bytecodes::_dreturn:
1077   case Bytecodes::_areturn:
1078     assert(rsize = -depth, "");
1079     inputs = rsize;
1080     break;
1081 
1082   case Bytecodes::_jsr:
1083   case Bytecodes::_jsr_w:
1084     inputs = 0;
1085     depth  = 1;                  // S.B. depth=1, not zero
1086     break;
1087 
1088   default:
1089     // bytecode produces a typed result
1090     inputs = rsize - depth;
1091     assert(inputs >= 0, "");
1092     break;
1093   }
1094 
1095 #ifdef ASSERT
1096   // spot check
1097   int outputs = depth + inputs;
1098   assert(outputs >= 0, "sanity");
1099   switch (code) {
1100   case Bytecodes::_checkcast: assert(inputs == 1 && outputs == 1, ""); break;
1101   case Bytecodes::_athrow:    assert(inputs == 1 && outputs == 0, ""); break;
1102   case Bytecodes::_aload_0:   assert(inputs == 0 && outputs == 1, ""); break;
1103   case Bytecodes::_return:    assert(inputs == 0 && outputs == 0, ""); break;
1104   case Bytecodes::_drem:      assert(inputs == 4 && outputs == 2, ""); break;
1105   }
1106 #endif //ASSERT
1107 
1108   return true;
1109 }
1110 
1111 
1112 
1113 //------------------------------basic_plus_adr---------------------------------
1114 Node* GraphKit::basic_plus_adr(Node* base, Node* ptr, Node* offset) {
1115   // short-circuit a common case
1116   if (offset == intcon(0))  return ptr;
1117   return _gvn.transform( new (C) AddPNode(base, ptr, offset) );
1118 }
1119 
1120 Node* GraphKit::ConvI2L(Node* offset) {
1121   // short-circuit a common case
1122   jint offset_con = find_int_con(offset, Type::OffsetBot);
1123   if (offset_con != Type::OffsetBot) {
1124     return longcon((jlong) offset_con);
1125   }
1126   return _gvn.transform( new (C) ConvI2LNode(offset));
1127 }
1128 
1129 Node* GraphKit::ConvI2UL(Node* offset) {
1130   juint offset_con = (juint) find_int_con(offset, Type::OffsetBot);
1131   if (offset_con != (juint) Type::OffsetBot) {
1132     return longcon((julong) offset_con);
1133   }
1134   Node* conv = _gvn.transform( new (C) ConvI2LNode(offset));
1135   Node* mask = _gvn.transform( ConLNode::make(C, (julong) max_juint) );
1136   return _gvn.transform( new (C) AndLNode(conv, mask) );
1137 }
1138 
1139 Node* GraphKit::ConvL2I(Node* offset) {
1140   // short-circuit a common case
1141   jlong offset_con = find_long_con(offset, (jlong)Type::OffsetBot);
1142   if (offset_con != (jlong)Type::OffsetBot) {
1143     return intcon((int) offset_con);
1144   }
1145   return _gvn.transform( new (C) ConvL2INode(offset));
1146 }
1147 
1148 //-------------------------load_object_klass-----------------------------------
1149 Node* GraphKit::load_object_klass(Node* obj) {
1150   // Special-case a fresh allocation to avoid building nodes:
1151   Node* akls = AllocateNode::Ideal_klass(obj, &_gvn);
1152   if (akls != NULL)  return akls;
1153   Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes());
1154   return _gvn.transform( LoadKlassNode::make(_gvn, immutable_memory(), k_adr, TypeInstPtr::KLASS) );
1155 }
1156 
1157 //-------------------------load_array_length-----------------------------------
1158 Node* GraphKit::load_array_length(Node* array) {
1159   // Special-case a fresh allocation to avoid building nodes:
1160   AllocateArrayNode* alloc = AllocateArrayNode::Ideal_array_allocation(array, &_gvn);
1161   Node *alen;
1162   if (alloc == NULL) {
1163     Node *r_adr = basic_plus_adr(array, arrayOopDesc::length_offset_in_bytes());
1164     alen = _gvn.transform( new (C) LoadRangeNode(0, immutable_memory(), r_adr, TypeInt::POS));
1165   } else {
1166     alen = alloc->Ideal_length();
1167     Node* ccast = alloc->make_ideal_length(_gvn.type(array)->is_oopptr(), &_gvn);
1168     if (ccast != alen) {
1169       alen = _gvn.transform(ccast);
1170     }
1171   }
1172   return alen;
1173 }
1174 
1175 //------------------------------do_null_check----------------------------------
1176 // Helper function to do a NULL pointer check.  Returned value is
1177 // the incoming address with NULL casted away.  You are allowed to use the
1178 // not-null value only if you are control dependent on the test.
1179 extern int explicit_null_checks_inserted,
1180            explicit_null_checks_elided;
1181 Node* GraphKit::null_check_common(Node* value, BasicType type,
1182                                   // optional arguments for variations:
1183                                   bool assert_null,
1184                                   Node* *null_control) {
1185   assert(!assert_null || null_control == NULL, "not both at once");
1186   if (stopped())  return top();
1187   if (!GenerateCompilerNullChecks && !assert_null && null_control == NULL) {
1188     // For some performance testing, we may wish to suppress null checking.
1189     value = cast_not_null(value);   // Make it appear to be non-null (4962416).
1190     return value;
1191   }
1192   explicit_null_checks_inserted++;
1193 
1194   // Construct NULL check
1195   Node *chk = NULL;
1196   switch(type) {
1197     case T_LONG   : chk = new (C) CmpLNode(value, _gvn.zerocon(T_LONG)); break;
1198     case T_INT    : chk = new (C) CmpINode(value, _gvn.intcon(0)); break;
1199     case T_ARRAY  : // fall through
1200       type = T_OBJECT;  // simplify further tests
1201     case T_OBJECT : {
1202       const Type *t = _gvn.type( value );
1203 
1204       const TypeOopPtr* tp = t->isa_oopptr();
1205       if (tp != NULL && tp->klass() != NULL && !tp->klass()->is_loaded()
1206           // Only for do_null_check, not any of its siblings:
1207           && !assert_null && null_control == NULL) {
1208         // Usually, any field access or invocation on an unloaded oop type
1209         // will simply fail to link, since the statically linked class is
1210         // likely also to be unloaded.  However, in -Xcomp mode, sometimes
1211         // the static class is loaded but the sharper oop type is not.
1212         // Rather than checking for this obscure case in lots of places,
1213         // we simply observe that a null check on an unloaded class
1214         // will always be followed by a nonsense operation, so we
1215         // can just issue the uncommon trap here.
1216         // Our access to the unloaded class will only be correct
1217         // after it has been loaded and initialized, which requires
1218         // a trip through the interpreter.
1219 #ifndef PRODUCT
1220         if (WizardMode) { tty->print("Null check of unloaded "); tp->klass()->print(); tty->cr(); }
1221 #endif
1222         uncommon_trap(Deoptimization::Reason_unloaded,
1223                       Deoptimization::Action_reinterpret,
1224                       tp->klass(), "!loaded");
1225         return top();
1226       }
1227 
1228       if (assert_null) {
1229         // See if the type is contained in NULL_PTR.
1230         // If so, then the value is already null.
1231         if (t->higher_equal(TypePtr::NULL_PTR)) {
1232           explicit_null_checks_elided++;
1233           return value;           // Elided null assert quickly!
1234         }
1235       } else {
1236         // See if mixing in the NULL pointer changes type.
1237         // If so, then the NULL pointer was not allowed in the original
1238         // type.  In other words, "value" was not-null.
1239         if (t->meet(TypePtr::NULL_PTR) != t->remove_speculative()) {
1240           // same as: if (!TypePtr::NULL_PTR->higher_equal(t)) ...
1241           explicit_null_checks_elided++;
1242           return value;           // Elided null check quickly!
1243         }
1244       }
1245       chk = new (C) CmpPNode( value, null() );
1246       break;
1247     }
1248 
1249     default:
1250       fatal(err_msg_res("unexpected type: %s", type2name(type)));
1251   }
1252   assert(chk != NULL, "sanity check");
1253   chk = _gvn.transform(chk);
1254 
1255   BoolTest::mask btest = assert_null ? BoolTest::eq : BoolTest::ne;
1256   BoolNode *btst = new (C) BoolNode( chk, btest);
1257   Node   *tst = _gvn.transform( btst );
1258 
1259   //-----------
1260   // if peephole optimizations occurred, a prior test existed.
1261   // If a prior test existed, maybe it dominates as we can avoid this test.
1262   if (tst != btst && type == T_OBJECT) {
1263     // At this point we want to scan up the CFG to see if we can
1264     // find an identical test (and so avoid this test altogether).
1265     Node *cfg = control();
1266     int depth = 0;
1267     while( depth < 16 ) {       // Limit search depth for speed
1268       if( cfg->Opcode() == Op_IfTrue &&
1269           cfg->in(0)->in(1) == tst ) {
1270         // Found prior test.  Use "cast_not_null" to construct an identical
1271         // CastPP (and hence hash to) as already exists for the prior test.
1272         // Return that casted value.
1273         if (assert_null) {
1274           replace_in_map(value, null());
1275           return null();  // do not issue the redundant test
1276         }
1277         Node *oldcontrol = control();
1278         set_control(cfg);
1279         Node *res = cast_not_null(value);
1280         set_control(oldcontrol);
1281         explicit_null_checks_elided++;
1282         return res;
1283       }
1284       cfg = IfNode::up_one_dom(cfg, /*linear_only=*/ true);
1285       if (cfg == NULL)  break;  // Quit at region nodes
1286       depth++;
1287     }
1288   }
1289 
1290   //-----------
1291   // Branch to failure if null
1292   float ok_prob = PROB_MAX;  // a priori estimate:  nulls never happen
1293   Deoptimization::DeoptReason reason;
1294   if (assert_null)
1295     reason = Deoptimization::Reason_null_assert;
1296   else if (type == T_OBJECT)
1297     reason = Deoptimization::Reason_null_check;
1298   else
1299     reason = Deoptimization::Reason_div0_check;
1300 
1301   // %%% Since Reason_unhandled is not recorded on a per-bytecode basis,
1302   // ciMethodData::has_trap_at will return a conservative -1 if any
1303   // must-be-null assertion has failed.  This could cause performance
1304   // problems for a method after its first do_null_assert failure.
1305   // Consider using 'Reason_class_check' instead?
1306 
1307   // To cause an implicit null check, we set the not-null probability
1308   // to the maximum (PROB_MAX).  For an explicit check the probability
1309   // is set to a smaller value.
1310   if (null_control != NULL || too_many_traps(reason)) {
1311     // probability is less likely
1312     ok_prob =  PROB_LIKELY_MAG(3);
1313   } else if (!assert_null &&
1314              (ImplicitNullCheckThreshold > 0) &&
1315              method() != NULL &&
1316              (method()->method_data()->trap_count(reason)
1317               >= (uint)ImplicitNullCheckThreshold)) {
1318     ok_prob =  PROB_LIKELY_MAG(3);
1319   }
1320 
1321   if (null_control != NULL) {
1322     IfNode* iff = create_and_map_if(control(), tst, ok_prob, COUNT_UNKNOWN);
1323     Node* null_true = _gvn.transform( new (C) IfFalseNode(iff));
1324     set_control(      _gvn.transform( new (C) IfTrueNode(iff)));
1325     if (null_true == top())
1326       explicit_null_checks_elided++;
1327     (*null_control) = null_true;
1328   } else {
1329     BuildCutout unless(this, tst, ok_prob);
1330     // Check for optimizer eliding test at parse time
1331     if (stopped()) {
1332       // Failure not possible; do not bother making uncommon trap.
1333       explicit_null_checks_elided++;
1334     } else if (assert_null) {
1335       uncommon_trap(reason,
1336                     Deoptimization::Action_make_not_entrant,
1337                     NULL, "assert_null");
1338     } else {
1339       replace_in_map(value, zerocon(type));
1340       builtin_throw(reason);
1341     }
1342   }
1343 
1344   // Must throw exception, fall-thru not possible?
1345   if (stopped()) {
1346     return top();               // No result
1347   }
1348 
1349   if (assert_null) {
1350     // Cast obj to null on this path.
1351     replace_in_map(value, zerocon(type));
1352     return zerocon(type);
1353   }
1354 
1355   // Cast obj to not-null on this path, if there is no null_control.
1356   // (If there is a null_control, a non-null value may come back to haunt us.)
1357   if (type == T_OBJECT) {
1358     Node* cast = cast_not_null(value, false);
1359     if (null_control == NULL || (*null_control) == top())
1360       replace_in_map(value, cast);
1361     value = cast;
1362   }
1363 
1364   return value;
1365 }
1366 
1367 
1368 //------------------------------cast_not_null----------------------------------
1369 // Cast obj to not-null on this path
1370 Node* GraphKit::cast_not_null(Node* obj, bool do_replace_in_map) {
1371   const Type *t = _gvn.type(obj);
1372   const Type *t_not_null = t->join_speculative(TypePtr::NOTNULL);
1373   // Object is already not-null?
1374   if( t == t_not_null ) return obj;
1375 
1376   Node *cast = new (C) CastPPNode(obj,t_not_null);
1377   cast->init_req(0, control());
1378   cast = _gvn.transform( cast );
1379 
1380   // Scan for instances of 'obj' in the current JVM mapping.
1381   // These instances are known to be not-null after the test.
1382   if (do_replace_in_map)
1383     replace_in_map(obj, cast);
1384 
1385   return cast;                  // Return casted value
1386 }
1387 
1388 
1389 //--------------------------replace_in_map-------------------------------------
1390 void GraphKit::replace_in_map(Node* old, Node* neww) {
1391   if (old == neww) {
1392     return;
1393   }
1394 
1395   map()->replace_edge(old, neww);
1396 
1397   // Note: This operation potentially replaces any edge
1398   // on the map.  This includes locals, stack, and monitors
1399   // of the current (innermost) JVM state.
1400 
1401   if (!ReplaceInParentMaps) {
1402     return;
1403   }
1404 
1405   // PreserveJVMState doesn't do a deep copy so we can't modify
1406   // parents
1407   if (Compile::current()->has_preserve_jvm_state()) {
1408     return;
1409   }
1410 
1411   Parse* parser = is_Parse();
1412   bool progress = true;
1413   Node* ctrl = map()->in(0);
1414   // Follow the chain of parsers and see whether the update can be
1415   // done in the map of callers. We can do the replace for a caller if
1416   // the current control post dominates the control of a caller.
1417   while (parser != NULL && parser->caller() != NULL && progress) {
1418     progress = false;
1419     Node* parent_map = parser->caller()->map();
1420     assert(parser->exits().map()->jvms()->depth() == parser->caller()->depth(), "map mismatch");
1421 
1422     Node* parent_ctrl = parent_map->in(0);
1423 
1424     while (parent_ctrl->is_Region()) {
1425       Node* n = parent_ctrl->as_Region()->is_copy();
1426       if (n == NULL) {
1427         break;
1428       }
1429       parent_ctrl = n;
1430     }
1431 
1432     for (;;) {
1433       if (ctrl == parent_ctrl) {
1434         // update the map of the exits which is the one that will be
1435         // used when compilation resume after inlining
1436         parser->exits().map()->replace_edge(old, neww);
1437         progress = true;
1438         break;
1439       }
1440       if (ctrl->is_Proj() && ctrl->as_Proj()->is_uncommon_trap_if_pattern(Deoptimization::Reason_none)) {
1441         ctrl = ctrl->in(0)->in(0);
1442       } else if (ctrl->is_Region()) {
1443         Node* n = ctrl->as_Region()->is_copy();
1444         if (n == NULL) {
1445           break;
1446         }
1447         ctrl = n;
1448       } else {
1449         break;
1450       }
1451     }
1452 
1453     parser = parser->parent_parser();
1454   }
1455 }
1456 
1457 
1458 //=============================================================================
1459 //--------------------------------memory---------------------------------------
1460 Node* GraphKit::memory(uint alias_idx) {
1461   MergeMemNode* mem = merged_memory();
1462   Node* p = mem->memory_at(alias_idx);
1463   _gvn.set_type(p, Type::MEMORY);  // must be mapped
1464   return p;
1465 }
1466 
1467 //-----------------------------reset_memory------------------------------------
1468 Node* GraphKit::reset_memory() {
1469   Node* mem = map()->memory();
1470   // do not use this node for any more parsing!
1471   debug_only( map()->set_memory((Node*)NULL) );
1472   return _gvn.transform( mem );
1473 }
1474 
1475 //------------------------------set_all_memory---------------------------------
1476 void GraphKit::set_all_memory(Node* newmem) {
1477   Node* mergemem = MergeMemNode::make(C, newmem);
1478   gvn().set_type_bottom(mergemem);
1479   map()->set_memory(mergemem);
1480 }
1481 
1482 //------------------------------set_all_memory_call----------------------------
1483 void GraphKit::set_all_memory_call(Node* call, bool separate_io_proj) {
1484   Node* newmem = _gvn.transform( new (C) ProjNode(call, TypeFunc::Memory, separate_io_proj) );
1485   set_all_memory(newmem);
1486 }
1487 
1488 //=============================================================================
1489 //
1490 // parser factory methods for MemNodes
1491 //
1492 // These are layered on top of the factory methods in LoadNode and StoreNode,
1493 // and integrate with the parser's memory state and _gvn engine.
1494 //
1495 
1496 // factory methods in "int adr_idx"
1497 Node* GraphKit::make_load(Node* ctl, Node* adr, const Type* t, BasicType bt,
1498                           int adr_idx,
1499                           MemNode::MemOrd mo, bool require_atomic_access) {
1500   assert(adr_idx != Compile::AliasIdxTop, "use other make_load factory" );
1501   const TypePtr* adr_type = NULL; // debug-mode-only argument
1502   debug_only(adr_type = C->get_adr_type(adr_idx));
1503   Node* mem = memory(adr_idx);
1504   Node* ld;
1505   if (require_atomic_access && bt == T_LONG) {
1506     ld = LoadLNode::make_atomic(C, ctl, mem, adr, adr_type, t, mo);
1507   } else {
1508     ld = LoadNode::make(_gvn, ctl, mem, adr, adr_type, t, bt, mo);
1509   }
1510   ld = _gvn.transform(ld);
1511   if ((bt == T_OBJECT) && C->do_escape_analysis() || C->eliminate_boxing()) {
1512     // Improve graph before escape analysis and boxing elimination.
1513     record_for_igvn(ld);
1514   }
1515   return ld;
1516 }
1517 
1518 Node* GraphKit::store_to_memory(Node* ctl, Node* adr, Node *val, BasicType bt,
1519                                 int adr_idx,
1520                                 MemNode::MemOrd mo,
1521                                 bool require_atomic_access) {
1522   assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
1523   const TypePtr* adr_type = NULL;
1524   debug_only(adr_type = C->get_adr_type(adr_idx));
1525   Node *mem = memory(adr_idx);
1526   Node* st;
1527   if (require_atomic_access && bt == T_LONG) {
1528     st = StoreLNode::make_atomic(C, ctl, mem, adr, adr_type, val, mo);
1529   } else {
1530     st = StoreNode::make(_gvn, ctl, mem, adr, adr_type, val, bt, mo);
1531   }
1532   st = _gvn.transform(st);
1533   set_memory(st, adr_idx);
1534   // Back-to-back stores can only remove intermediate store with DU info
1535   // so push on worklist for optimizer.
1536   if (mem->req() > MemNode::Address && adr == mem->in(MemNode::Address))
1537     record_for_igvn(st);
1538 
1539   return st;
1540 }
1541 
1542 
1543 void GraphKit::pre_barrier(bool do_load,
1544                            Node* ctl,
1545                            Node* obj,
1546                            Node* adr,
1547                            uint  adr_idx,
1548                            Node* val,
1549                            const TypeOopPtr* val_type,
1550                            Node* pre_val,
1551                            BasicType bt) {
1552 
1553   BarrierSet* bs = Universe::heap()->barrier_set();
1554   set_control(ctl);
1555   switch (bs->kind()) {
1556     case BarrierSet::G1SATBCT:
1557     case BarrierSet::G1SATBCTLogging:
1558       g1_write_barrier_pre(do_load, obj, adr, adr_idx, val, val_type, pre_val, bt);
1559       break;
1560 
1561     case BarrierSet::CardTableModRef:
1562     case BarrierSet::CardTableExtension:
1563     case BarrierSet::ModRef:
1564       break;
1565 
1566     case BarrierSet::Other:
1567     default      :
1568       ShouldNotReachHere();
1569 
1570   }
1571 }
1572 
1573 bool GraphKit::can_move_pre_barrier() const {
1574   BarrierSet* bs = Universe::heap()->barrier_set();
1575   switch (bs->kind()) {
1576     case BarrierSet::G1SATBCT:
1577     case BarrierSet::G1SATBCTLogging:
1578       return true; // Can move it if no safepoint
1579 
1580     case BarrierSet::CardTableModRef:
1581     case BarrierSet::CardTableExtension:
1582     case BarrierSet::ModRef:
1583       return true; // There is no pre-barrier
1584 
1585     case BarrierSet::Other:
1586     default      :
1587       ShouldNotReachHere();
1588   }
1589   return false;
1590 }
1591 
1592 void GraphKit::post_barrier(Node* ctl,
1593                             Node* store,
1594                             Node* obj,
1595                             Node* adr,
1596                             uint  adr_idx,
1597                             Node* val,
1598                             BasicType bt,
1599                             bool use_precise) {
1600   BarrierSet* bs = Universe::heap()->barrier_set();
1601   set_control(ctl);
1602   switch (bs->kind()) {
1603     case BarrierSet::G1SATBCT:
1604     case BarrierSet::G1SATBCTLogging:
1605       g1_write_barrier_post(store, obj, adr, adr_idx, val, bt, use_precise);
1606       break;
1607 
1608     case BarrierSet::CardTableModRef:
1609     case BarrierSet::CardTableExtension:
1610       write_barrier_post(store, obj, adr, adr_idx, val, use_precise);
1611       break;
1612 
1613     case BarrierSet::ModRef:
1614       break;
1615 
1616     case BarrierSet::Other:
1617     default      :
1618       ShouldNotReachHere();
1619 
1620   }
1621 }
1622 
1623 Node* GraphKit::store_oop(Node* ctl,
1624                           Node* obj,
1625                           Node* adr,
1626                           const TypePtr* adr_type,
1627                           Node* val,
1628                           const TypeOopPtr* val_type,
1629                           BasicType bt,
1630                           bool use_precise,
1631                           MemNode::MemOrd mo) {
1632   // Transformation of a value which could be NULL pointer (CastPP #NULL)
1633   // could be delayed during Parse (for example, in adjust_map_after_if()).
1634   // Execute transformation here to avoid barrier generation in such case.
1635   if (_gvn.type(val) == TypePtr::NULL_PTR)
1636     val = _gvn.makecon(TypePtr::NULL_PTR);
1637 
1638   set_control(ctl);
1639   if (stopped()) return top(); // Dead path ?
1640 
1641   assert(bt == T_OBJECT, "sanity");
1642   assert(val != NULL, "not dead path");
1643   uint adr_idx = C->get_alias_index(adr_type);
1644   assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
1645 
1646   pre_barrier(true /* do_load */,
1647               control(), obj, adr, adr_idx, val, val_type,
1648               NULL /* pre_val */,
1649               bt);
1650 
1651   Node* store = store_to_memory(control(), adr, val, bt, adr_idx, mo);
1652   post_barrier(control(), store, obj, adr, adr_idx, val, bt, use_precise);
1653   return store;
1654 }
1655 
1656 // Could be an array or object we don't know at compile time (unsafe ref.)
1657 Node* GraphKit::store_oop_to_unknown(Node* ctl,
1658                              Node* obj,   // containing obj
1659                              Node* adr,  // actual adress to store val at
1660                              const TypePtr* adr_type,
1661                              Node* val,
1662                              BasicType bt,
1663                              MemNode::MemOrd mo) {
1664   Compile::AliasType* at = C->alias_type(adr_type);
1665   const TypeOopPtr* val_type = NULL;
1666   if (adr_type->isa_instptr()) {
1667     if (at->field() != NULL) {
1668       // known field.  This code is a copy of the do_put_xxx logic.
1669       ciField* field = at->field();
1670       if (!field->type()->is_loaded()) {
1671         val_type = TypeInstPtr::BOTTOM;
1672       } else {
1673         val_type = TypeOopPtr::make_from_klass(field->type()->as_klass());
1674       }
1675     }
1676   } else if (adr_type->isa_aryptr()) {
1677     val_type = adr_type->is_aryptr()->elem()->make_oopptr();
1678   }
1679   if (val_type == NULL) {
1680     val_type = TypeInstPtr::BOTTOM;
1681   }
1682   return store_oop(ctl, obj, adr, adr_type, val, val_type, bt, true, mo);
1683 }
1684 
1685 
1686 //-------------------------array_element_address-------------------------
1687 Node* GraphKit::array_element_address(Node* ary, Node* idx, BasicType elembt,
1688                                       const TypeInt* sizetype) {
1689   uint shift  = exact_log2(type2aelembytes(elembt));
1690   uint header = arrayOopDesc::base_offset_in_bytes(elembt);
1691 
1692   // short-circuit a common case (saves lots of confusing waste motion)
1693   jint idx_con = find_int_con(idx, -1);
1694   if (idx_con >= 0) {
1695     intptr_t offset = header + ((intptr_t)idx_con << shift);
1696     return basic_plus_adr(ary, offset);
1697   }
1698 
1699   // must be correct type for alignment purposes
1700   Node* base  = basic_plus_adr(ary, header);
1701 #ifdef _LP64
1702   // The scaled index operand to AddP must be a clean 64-bit value.
1703   // Java allows a 32-bit int to be incremented to a negative
1704   // value, which appears in a 64-bit register as a large
1705   // positive number.  Using that large positive number as an
1706   // operand in pointer arithmetic has bad consequences.
1707   // On the other hand, 32-bit overflow is rare, and the possibility
1708   // can often be excluded, if we annotate the ConvI2L node with
1709   // a type assertion that its value is known to be a small positive
1710   // number.  (The prior range check has ensured this.)
1711   // This assertion is used by ConvI2LNode::Ideal.
1712   int index_max = max_jint - 1;  // array size is max_jint, index is one less
1713   if (sizetype != NULL)  index_max = sizetype->_hi - 1;
1714   const TypeLong* lidxtype = TypeLong::make(CONST64(0), index_max, Type::WidenMax);
1715   idx = _gvn.transform( new (C) ConvI2LNode(idx, lidxtype) );
1716 #endif
1717   Node* scale = _gvn.transform( new (C) LShiftXNode(idx, intcon(shift)) );
1718   return basic_plus_adr(ary, base, scale);
1719 }
1720 
1721 //-------------------------load_array_element-------------------------
1722 Node* GraphKit::load_array_element(Node* ctl, Node* ary, Node* idx, const TypeAryPtr* arytype) {
1723   const Type* elemtype = arytype->elem();
1724   BasicType elembt = elemtype->array_element_basic_type();
1725   Node* adr = array_element_address(ary, idx, elembt, arytype->size());
1726   Node* ld = make_load(ctl, adr, elemtype, elembt, arytype, MemNode::unordered);
1727   return ld;
1728 }
1729 
1730 //-------------------------set_arguments_for_java_call-------------------------
1731 // Arguments (pre-popped from the stack) are taken from the JVMS.
1732 void GraphKit::set_arguments_for_java_call(CallJavaNode* call) {
1733   // Add the call arguments:
1734   uint nargs = call->method()->arg_size();
1735   for (uint i = 0; i < nargs; i++) {
1736     Node* arg = argument(i);
1737     call->init_req(i + TypeFunc::Parms, arg);
1738   }
1739 }
1740 
1741 //---------------------------set_edges_for_java_call---------------------------
1742 // Connect a newly created call into the current JVMS.
1743 // A return value node (if any) is returned from set_edges_for_java_call.
1744 void GraphKit::set_edges_for_java_call(CallJavaNode* call, bool must_throw, bool separate_io_proj) {
1745 
1746   // Add the predefined inputs:
1747   call->init_req( TypeFunc::Control, control() );
1748   call->init_req( TypeFunc::I_O    , i_o() );
1749   call->init_req( TypeFunc::Memory , reset_memory() );
1750   call->init_req( TypeFunc::FramePtr, frameptr() );
1751   call->init_req( TypeFunc::ReturnAdr, top() );
1752 
1753   add_safepoint_edges(call, must_throw);
1754 
1755   Node* xcall = _gvn.transform(call);
1756 
1757   if (xcall == top()) {
1758     set_control(top());
1759     return;
1760   }
1761   assert(xcall == call, "call identity is stable");
1762 
1763   // Re-use the current map to produce the result.
1764 
1765   set_control(_gvn.transform(new (C) ProjNode(call, TypeFunc::Control)));
1766   set_i_o(    _gvn.transform(new (C) ProjNode(call, TypeFunc::I_O    , separate_io_proj)));
1767   set_all_memory_call(xcall, separate_io_proj);
1768 
1769   //return xcall;   // no need, caller already has it
1770 }
1771 
1772 Node* GraphKit::set_results_for_java_call(CallJavaNode* call, bool separate_io_proj) {
1773   if (stopped())  return top();  // maybe the call folded up?
1774 
1775   // Capture the return value, if any.
1776   Node* ret;
1777   if (call->method() == NULL ||
1778       call->method()->return_type()->basic_type() == T_VOID)
1779         ret = top();
1780   else  ret = _gvn.transform(new (C) ProjNode(call, TypeFunc::Parms));
1781 
1782   // Note:  Since any out-of-line call can produce an exception,
1783   // we always insert an I_O projection from the call into the result.
1784 
1785   make_slow_call_ex(call, env()->Throwable_klass(), separate_io_proj);
1786 
1787   if (separate_io_proj) {
1788     // The caller requested separate projections be used by the fall
1789     // through and exceptional paths, so replace the projections for
1790     // the fall through path.
1791     set_i_o(_gvn.transform( new (C) ProjNode(call, TypeFunc::I_O) ));
1792     set_all_memory(_gvn.transform( new (C) ProjNode(call, TypeFunc::Memory) ));
1793   }
1794   return ret;
1795 }
1796 
1797 //--------------------set_predefined_input_for_runtime_call--------------------
1798 // Reading and setting the memory state is way conservative here.
1799 // The real problem is that I am not doing real Type analysis on memory,
1800 // so I cannot distinguish card mark stores from other stores.  Across a GC
1801 // point the Store Barrier and the card mark memory has to agree.  I cannot
1802 // have a card mark store and its barrier split across the GC point from
1803 // either above or below.  Here I get that to happen by reading ALL of memory.
1804 // A better answer would be to separate out card marks from other memory.
1805 // For now, return the input memory state, so that it can be reused
1806 // after the call, if this call has restricted memory effects.
1807 Node* GraphKit::set_predefined_input_for_runtime_call(SafePointNode* call) {
1808   // Set fixed predefined input arguments
1809   Node* memory = reset_memory();
1810   call->init_req( TypeFunc::Control,   control()  );
1811   call->init_req( TypeFunc::I_O,       top()      ); // does no i/o
1812   call->init_req( TypeFunc::Memory,    memory     ); // may gc ptrs
1813   call->init_req( TypeFunc::FramePtr,  frameptr() );
1814   call->init_req( TypeFunc::ReturnAdr, top()      );
1815   return memory;
1816 }
1817 
1818 //-------------------set_predefined_output_for_runtime_call--------------------
1819 // Set control and memory (not i_o) from the call.
1820 // If keep_mem is not NULL, use it for the output state,
1821 // except for the RawPtr output of the call, if hook_mem is TypeRawPtr::BOTTOM.
1822 // If hook_mem is NULL, this call produces no memory effects at all.
1823 // If hook_mem is a Java-visible memory slice (such as arraycopy operands),
1824 // then only that memory slice is taken from the call.
1825 // In the last case, we must put an appropriate memory barrier before
1826 // the call, so as to create the correct anti-dependencies on loads
1827 // preceding the call.
1828 void GraphKit::set_predefined_output_for_runtime_call(Node* call,
1829                                                       Node* keep_mem,
1830                                                       const TypePtr* hook_mem) {
1831   // no i/o
1832   set_control(_gvn.transform( new (C) ProjNode(call,TypeFunc::Control) ));
1833   if (keep_mem) {
1834     // First clone the existing memory state
1835     set_all_memory(keep_mem);
1836     if (hook_mem != NULL) {
1837       // Make memory for the call
1838       Node* mem = _gvn.transform( new (C) ProjNode(call, TypeFunc::Memory) );
1839       // Set the RawPtr memory state only.  This covers all the heap top/GC stuff
1840       // We also use hook_mem to extract specific effects from arraycopy stubs.
1841       set_memory(mem, hook_mem);
1842     }
1843     // ...else the call has NO memory effects.
1844 
1845     // Make sure the call advertises its memory effects precisely.
1846     // This lets us build accurate anti-dependences in gcm.cpp.
1847     assert(C->alias_type(call->adr_type()) == C->alias_type(hook_mem),
1848            "call node must be constructed correctly");
1849   } else {
1850     assert(hook_mem == NULL, "");
1851     // This is not a "slow path" call; all memory comes from the call.
1852     set_all_memory_call(call);
1853   }
1854 }
1855 
1856 
1857 // Replace the call with the current state of the kit.
1858 void GraphKit::replace_call(CallNode* call, Node* result) {
1859   JVMState* ejvms = NULL;
1860   if (has_exceptions()) {
1861     ejvms = transfer_exceptions_into_jvms();
1862   }
1863 
1864   SafePointNode* final_state = stop();
1865 
1866   // Find all the needed outputs of this call
1867   CallProjections callprojs;
1868   call->extract_projections(&callprojs, true);
1869 
1870   Node* init_mem = call->in(TypeFunc::Memory);
1871   Node* final_mem = final_state->in(TypeFunc::Memory);
1872   Node* final_ctl = final_state->in(TypeFunc::Control);
1873   Node* final_io = final_state->in(TypeFunc::I_O);
1874 
1875   // Replace all the old call edges with the edges from the inlining result
1876   if (callprojs.fallthrough_catchproj != NULL) {
1877     C->gvn_replace_by(callprojs.fallthrough_catchproj, final_ctl);
1878   }
1879   if (callprojs.fallthrough_memproj != NULL) {
1880     C->gvn_replace_by(callprojs.fallthrough_memproj,   final_mem);
1881   }
1882   if (callprojs.fallthrough_ioproj != NULL) {
1883     C->gvn_replace_by(callprojs.fallthrough_ioproj,    final_io);
1884   }
1885 
1886   // Replace the result with the new result if it exists and is used
1887   if (callprojs.resproj != NULL && result != NULL) {
1888     C->gvn_replace_by(callprojs.resproj, result);
1889   }
1890 
1891   if (ejvms == NULL) {
1892     // No exception edges to simply kill off those paths
1893     if (callprojs.catchall_catchproj != NULL) {
1894       C->gvn_replace_by(callprojs.catchall_catchproj, C->top());
1895     }
1896     if (callprojs.catchall_memproj != NULL) {
1897       C->gvn_replace_by(callprojs.catchall_memproj,   C->top());
1898     }
1899     if (callprojs.catchall_ioproj != NULL) {
1900       C->gvn_replace_by(callprojs.catchall_ioproj,    C->top());
1901     }
1902     // Replace the old exception object with top
1903     if (callprojs.exobj != NULL) {
1904       C->gvn_replace_by(callprojs.exobj, C->top());
1905     }
1906   } else {
1907     GraphKit ekit(ejvms);
1908 
1909     // Load my combined exception state into the kit, with all phis transformed:
1910     SafePointNode* ex_map = ekit.combine_and_pop_all_exception_states();
1911 
1912     Node* ex_oop = ekit.use_exception_state(ex_map);
1913     if (callprojs.catchall_catchproj != NULL) {
1914       C->gvn_replace_by(callprojs.catchall_catchproj, ekit.control());
1915     }
1916     if (callprojs.catchall_memproj != NULL) {
1917       C->gvn_replace_by(callprojs.catchall_memproj,   ekit.reset_memory());
1918     }
1919     if (callprojs.catchall_ioproj != NULL) {
1920       C->gvn_replace_by(callprojs.catchall_ioproj,    ekit.i_o());
1921     }
1922 
1923     // Replace the old exception object with the newly created one
1924     if (callprojs.exobj != NULL) {
1925       C->gvn_replace_by(callprojs.exobj, ex_oop);
1926     }
1927   }
1928 
1929   // Disconnect the call from the graph
1930   call->disconnect_inputs(NULL, C);
1931   C->gvn_replace_by(call, C->top());
1932 
1933   // Clean up any MergeMems that feed other MergeMems since the
1934   // optimizer doesn't like that.
1935   if (final_mem->is_MergeMem()) {
1936     Node_List wl;
1937     for (SimpleDUIterator i(final_mem); i.has_next(); i.next()) {
1938       Node* m = i.get();
1939       if (m->is_MergeMem() && !wl.contains(m)) {
1940         wl.push(m);
1941       }
1942     }
1943     while (wl.size()  > 0) {
1944       _gvn.transform(wl.pop());
1945     }
1946   }
1947 }
1948 
1949 
1950 //------------------------------increment_counter------------------------------
1951 // for statistics: increment a VM counter by 1
1952 
1953 void GraphKit::increment_counter(address counter_addr) {
1954   Node* adr1 = makecon(TypeRawPtr::make(counter_addr));
1955   increment_counter(adr1);
1956 }
1957 
1958 void GraphKit::increment_counter(Node* counter_addr) {
1959   int adr_type = Compile::AliasIdxRaw;
1960   Node* ctrl = control();
1961   Node* cnt  = make_load(ctrl, counter_addr, TypeInt::INT, T_INT, adr_type, MemNode::unordered);
1962   Node* incr = _gvn.transform(new (C) AddINode(cnt, _gvn.intcon(1)));
1963   store_to_memory(ctrl, counter_addr, incr, T_INT, adr_type, MemNode::unordered);
1964 }
1965 
1966 
1967 //------------------------------uncommon_trap----------------------------------
1968 // Bail out to the interpreter in mid-method.  Implemented by calling the
1969 // uncommon_trap blob.  This helper function inserts a runtime call with the
1970 // right debug info.
1971 void GraphKit::uncommon_trap(int trap_request,
1972                              ciKlass* klass, const char* comment,
1973                              bool must_throw,
1974                              bool keep_exact_action) {
1975   if (failing())  stop();
1976   if (stopped())  return; // trap reachable?
1977 
1978   // Note:  If ProfileTraps is true, and if a deopt. actually
1979   // occurs here, the runtime will make sure an MDO exists.  There is
1980   // no need to call method()->ensure_method_data() at this point.
1981 
1982   // Set the stack pointer to the right value for reexecution:
1983   set_sp(reexecute_sp());
1984 
1985 #ifdef ASSERT
1986   if (!must_throw) {
1987     // Make sure the stack has at least enough depth to execute
1988     // the current bytecode.
1989     int inputs, ignored_depth;
1990     if (compute_stack_effects(inputs, ignored_depth)) {
1991       assert(sp() >= inputs, err_msg_res("must have enough JVMS stack to execute %s: sp=%d, inputs=%d",
1992              Bytecodes::name(java_bc()), sp(), inputs));
1993     }
1994   }
1995 #endif
1996 
1997   Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(trap_request);
1998   Deoptimization::DeoptAction action = Deoptimization::trap_request_action(trap_request);
1999 
2000   switch (action) {
2001   case Deoptimization::Action_maybe_recompile:
2002   case Deoptimization::Action_reinterpret:
2003     // Temporary fix for 6529811 to allow virtual calls to be sure they
2004     // get the chance to go from mono->bi->mega
2005     if (!keep_exact_action &&
2006         Deoptimization::trap_request_index(trap_request) < 0 &&
2007         too_many_recompiles(reason)) {
2008       // This BCI is causing too many recompilations.
2009       action = Deoptimization::Action_none;
2010       trap_request = Deoptimization::make_trap_request(reason, action);
2011     } else {
2012       C->set_trap_can_recompile(true);
2013     }
2014     break;
2015   case Deoptimization::Action_make_not_entrant:
2016     C->set_trap_can_recompile(true);
2017     break;
2018 #ifdef ASSERT
2019   case Deoptimization::Action_none:
2020   case Deoptimization::Action_make_not_compilable:
2021     break;
2022   default:
2023     fatal(err_msg_res("unknown action %d: %s", action, Deoptimization::trap_action_name(action)));
2024     break;
2025 #endif
2026   }
2027 
2028   if (TraceOptoParse) {
2029     char buf[100];
2030     tty->print_cr("Uncommon trap %s at bci:%d",
2031                   Deoptimization::format_trap_request(buf, sizeof(buf),
2032                                                       trap_request), bci());
2033   }
2034 
2035   CompileLog* log = C->log();
2036   if (log != NULL) {
2037     int kid = (klass == NULL)? -1: log->identify(klass);
2038     log->begin_elem("uncommon_trap bci='%d'", bci());
2039     char buf[100];
2040     log->print(" %s", Deoptimization::format_trap_request(buf, sizeof(buf),
2041                                                           trap_request));
2042     if (kid >= 0)         log->print(" klass='%d'", kid);
2043     if (comment != NULL)  log->print(" comment='%s'", comment);
2044     log->end_elem();
2045   }
2046 
2047   // Make sure any guarding test views this path as very unlikely
2048   Node *i0 = control()->in(0);
2049   if (i0 != NULL && i0->is_If()) {        // Found a guarding if test?
2050     IfNode *iff = i0->as_If();
2051     float f = iff->_prob;   // Get prob
2052     if (control()->Opcode() == Op_IfTrue) {
2053       if (f > PROB_UNLIKELY_MAG(4))
2054         iff->_prob = PROB_MIN;
2055     } else {
2056       if (f < PROB_LIKELY_MAG(4))
2057         iff->_prob = PROB_MAX;
2058     }
2059   }
2060 
2061   // Clear out dead values from the debug info.
2062   kill_dead_locals();
2063 
2064   // Now insert the uncommon trap subroutine call
2065   address call_addr = SharedRuntime::uncommon_trap_blob()->entry_point();
2066   const TypePtr* no_memory_effects = NULL;
2067   // Pass the index of the class to be loaded
2068   Node* call = make_runtime_call(RC_NO_LEAF | RC_UNCOMMON |
2069                                  (must_throw ? RC_MUST_THROW : 0),
2070                                  OptoRuntime::uncommon_trap_Type(),
2071                                  call_addr, "uncommon_trap", no_memory_effects,
2072                                  intcon(trap_request));
2073   assert(call->as_CallStaticJava()->uncommon_trap_request() == trap_request,
2074          "must extract request correctly from the graph");
2075   assert(trap_request != 0, "zero value reserved by uncommon_trap_request");
2076 
2077   call->set_req(TypeFunc::ReturnAdr, returnadr());
2078   // The debug info is the only real input to this call.
2079 
2080   // Halt-and-catch fire here.  The above call should never return!
2081   HaltNode* halt = new(C) HaltNode(control(), frameptr());
2082   _gvn.set_type_bottom(halt);
2083   root()->add_req(halt);
2084 
2085   stop_and_kill_map();
2086 }
2087 
2088 
2089 //--------------------------just_allocated_object------------------------------
2090 // Report the object that was just allocated.
2091 // It must be the case that there are no intervening safepoints.
2092 // We use this to determine if an object is so "fresh" that
2093 // it does not require card marks.
2094 Node* GraphKit::just_allocated_object(Node* current_control) {
2095   if (C->recent_alloc_ctl() == current_control)
2096     return C->recent_alloc_obj();
2097   return NULL;
2098 }
2099 
2100 
2101 void GraphKit::round_double_arguments(ciMethod* dest_method) {
2102   // (Note:  TypeFunc::make has a cache that makes this fast.)
2103   const TypeFunc* tf    = TypeFunc::make(dest_method);
2104   int             nargs = tf->_domain->_cnt - TypeFunc::Parms;
2105   for (int j = 0; j < nargs; j++) {
2106     const Type *targ = tf->_domain->field_at(j + TypeFunc::Parms);
2107     if( targ->basic_type() == T_DOUBLE ) {
2108       // If any parameters are doubles, they must be rounded before
2109       // the call, dstore_rounding does gvn.transform
2110       Node *arg = argument(j);
2111       arg = dstore_rounding(arg);
2112       set_argument(j, arg);
2113     }
2114   }
2115 }
2116 
2117 /**
2118  * Record profiling data exact_kls for Node n with the type system so
2119  * that it can propagate it (speculation)
2120  *
2121  * @param n          node that the type applies to
2122  * @param exact_kls  type from profiling
2123  *
2124  * @return           node with improved type
2125  */
2126 Node* GraphKit::record_profile_for_speculation(Node* n, ciKlass* exact_kls) {
2127   const Type* current_type = _gvn.type(n);
2128   assert(UseTypeSpeculation, "type speculation must be on");
2129 
2130   const TypeOopPtr* speculative = current_type->speculative();
2131 
2132   if (current_type->would_improve_type(exact_kls, jvms()->depth())) {
2133     const TypeKlassPtr* tklass = TypeKlassPtr::make(exact_kls);
2134     const TypeOopPtr* xtype = tklass->as_instance_type();
2135     assert(xtype->klass_is_exact(), "Should be exact");
2136     // record the new speculative type's depth
2137     speculative = xtype->with_inline_depth(jvms()->depth());
2138   }
2139 
2140   if (speculative != current_type->speculative()) {
2141     // Build a type with a speculative type (what we think we know
2142     // about the type but will need a guard when we use it)
2143     const TypeOopPtr* spec_type = TypeOopPtr::make(TypePtr::BotPTR, Type::OffsetBot, TypeOopPtr::InstanceBot, speculative);
2144     // We're changing the type, we need a new CheckCast node to carry
2145     // the new type. The new type depends on the control: what
2146     // profiling tells us is only valid from here as far as we can
2147     // tell.
2148     Node* cast = new(C) CheckCastPPNode(control(), n, current_type->remove_speculative()->join_speculative(spec_type));
2149     cast = _gvn.transform(cast);
2150     replace_in_map(n, cast);
2151     n = cast;
2152   }
2153 
2154   return n;
2155 }
2156 
2157 /**
2158  * Record profiling data from receiver profiling at an invoke with the
2159  * type system so that it can propagate it (speculation)
2160  *
2161  * @param n  receiver node
2162  *
2163  * @return   node with improved type
2164  */
2165 Node* GraphKit::record_profiled_receiver_for_speculation(Node* n) {
2166   if (!UseTypeSpeculation) {
2167     return n;
2168   }
2169   ciKlass* exact_kls = profile_has_unique_klass();
2170   return record_profile_for_speculation(n, exact_kls);
2171 }
2172 
2173 /**
2174  * Record profiling data from argument profiling at an invoke with the
2175  * type system so that it can propagate it (speculation)
2176  *
2177  * @param dest_method  target method for the call
2178  * @param bc           what invoke bytecode is this?
2179  */
2180 void GraphKit::record_profiled_arguments_for_speculation(ciMethod* dest_method, Bytecodes::Code bc) {
2181   if (!UseTypeSpeculation) {
2182     return;
2183   }
2184   const TypeFunc* tf    = TypeFunc::make(dest_method);
2185   int             nargs = tf->_domain->_cnt - TypeFunc::Parms;
2186   int skip = Bytecodes::has_receiver(bc) ? 1 : 0;
2187   for (int j = skip, i = 0; j < nargs && i < TypeProfileArgsLimit; j++) {
2188     const Type *targ = tf->_domain->field_at(j + TypeFunc::Parms);
2189     if (targ->basic_type() == T_OBJECT || targ->basic_type() == T_ARRAY) {
2190       ciKlass* better_type = method()->argument_profiled_type(bci(), i);
2191       if (better_type != NULL) {
2192         record_profile_for_speculation(argument(j), better_type);
2193       }
2194       i++;
2195     }
2196   }
2197 }
2198 
2199 /**
2200  * Record profiling data from parameter profiling at an invoke with
2201  * the type system so that it can propagate it (speculation)
2202  */
2203 void GraphKit::record_profiled_parameters_for_speculation() {
2204   if (!UseTypeSpeculation) {
2205     return;
2206   }
2207   for (int i = 0, j = 0; i < method()->arg_size() ; i++) {
2208     if (_gvn.type(local(i))->isa_oopptr()) {
2209       ciKlass* better_type = method()->parameter_profiled_type(j);
2210       if (better_type != NULL) {
2211         record_profile_for_speculation(local(i), better_type);
2212       }
2213       j++;
2214     }
2215   }
2216 }
2217 
2218 void GraphKit::round_double_result(ciMethod* dest_method) {
2219   // A non-strict method may return a double value which has an extended
2220   // exponent, but this must not be visible in a caller which is 'strict'
2221   // If a strict caller invokes a non-strict callee, round a double result
2222 
2223   BasicType result_type = dest_method->return_type()->basic_type();
2224   assert( method() != NULL, "must have caller context");
2225   if( result_type == T_DOUBLE && method()->is_strict() && !dest_method->is_strict() ) {
2226     // Destination method's return value is on top of stack
2227     // dstore_rounding() does gvn.transform
2228     Node *result = pop_pair();
2229     result = dstore_rounding(result);
2230     push_pair(result);
2231   }
2232 }
2233 
2234 // rounding for strict float precision conformance
2235 Node* GraphKit::precision_rounding(Node* n) {
2236   return UseStrictFP && _method->flags().is_strict()
2237     && UseSSE == 0 && Matcher::strict_fp_requires_explicit_rounding
2238     ? _gvn.transform( new (C) RoundFloatNode(0, n) )
2239     : n;
2240 }
2241 
2242 // rounding for strict double precision conformance
2243 Node* GraphKit::dprecision_rounding(Node *n) {
2244   return UseStrictFP && _method->flags().is_strict()
2245     && UseSSE <= 1 && Matcher::strict_fp_requires_explicit_rounding
2246     ? _gvn.transform( new (C) RoundDoubleNode(0, n) )
2247     : n;
2248 }
2249 
2250 // rounding for non-strict double stores
2251 Node* GraphKit::dstore_rounding(Node* n) {
2252   return Matcher::strict_fp_requires_explicit_rounding
2253     && UseSSE <= 1
2254     ? _gvn.transform( new (C) RoundDoubleNode(0, n) )
2255     : n;
2256 }
2257 
2258 //=============================================================================
2259 // Generate a fast path/slow path idiom.  Graph looks like:
2260 // [foo] indicates that 'foo' is a parameter
2261 //
2262 //              [in]     NULL
2263 //                 \    /
2264 //                  CmpP
2265 //                  Bool ne
2266 //                   If
2267 //                  /  \
2268 //              True    False-<2>
2269 //              / |
2270 //             /  cast_not_null
2271 //           Load  |    |   ^
2272 //        [fast_test]   |   |
2273 // gvn to   opt_test    |   |
2274 //          /    \      |  <1>
2275 //      True     False  |
2276 //        |         \\  |
2277 //   [slow_call]     \[fast_result]
2278 //    Ctl   Val       \      \
2279 //     |               \      \
2280 //    Catch       <1>   \      \
2281 //   /    \        ^     \      \
2282 //  Ex    No_Ex    |      \      \
2283 //  |       \   \  |       \ <2>  \
2284 //  ...      \  [slow_res] |  |    \   [null_result]
2285 //            \         \--+--+---  |  |
2286 //             \           | /    \ | /
2287 //              --------Region     Phi
2288 //
2289 //=============================================================================
2290 // Code is structured as a series of driver functions all called 'do_XXX' that
2291 // call a set of helper functions.  Helper functions first, then drivers.
2292 
2293 //------------------------------null_check_oop---------------------------------
2294 // Null check oop.  Set null-path control into Region in slot 3.
2295 // Make a cast-not-nullness use the other not-null control.  Return cast.
2296 Node* GraphKit::null_check_oop(Node* value, Node* *null_control,
2297                                bool never_see_null, bool safe_for_replace) {
2298   // Initial NULL check taken path
2299   (*null_control) = top();
2300   Node* cast = null_check_common(value, T_OBJECT, false, null_control);
2301 
2302   // Generate uncommon_trap:
2303   if (never_see_null && (*null_control) != top()) {
2304     // If we see an unexpected null at a check-cast we record it and force a
2305     // recompile; the offending check-cast will be compiled to handle NULLs.
2306     // If we see more than one offending BCI, then all checkcasts in the
2307     // method will be compiled to handle NULLs.
2308     PreserveJVMState pjvms(this);
2309     set_control(*null_control);
2310     replace_in_map(value, null());
2311     uncommon_trap(Deoptimization::Reason_null_check,
2312                   Deoptimization::Action_make_not_entrant);
2313     (*null_control) = top();    // NULL path is dead
2314   }
2315   if ((*null_control) == top() && safe_for_replace) {
2316     replace_in_map(value, cast);
2317   }
2318 
2319   // Cast away null-ness on the result
2320   return cast;
2321 }
2322 
2323 //------------------------------opt_iff----------------------------------------
2324 // Optimize the fast-check IfNode.  Set the fast-path region slot 2.
2325 // Return slow-path control.
2326 Node* GraphKit::opt_iff(Node* region, Node* iff) {
2327   IfNode *opt_iff = _gvn.transform(iff)->as_If();
2328 
2329   // Fast path taken; set region slot 2
2330   Node *fast_taken = _gvn.transform( new (C) IfFalseNode(opt_iff) );
2331   region->init_req(2,fast_taken); // Capture fast-control
2332 
2333   // Fast path not-taken, i.e. slow path
2334   Node *slow_taken = _gvn.transform( new (C) IfTrueNode(opt_iff) );
2335   return slow_taken;
2336 }
2337 
2338 //-----------------------------make_runtime_call-------------------------------
2339 Node* GraphKit::make_runtime_call(int flags,
2340                                   const TypeFunc* call_type, address call_addr,
2341                                   const char* call_name,
2342                                   const TypePtr* adr_type,
2343                                   // The following parms are all optional.
2344                                   // The first NULL ends the list.
2345                                   Node* parm0, Node* parm1,
2346                                   Node* parm2, Node* parm3,
2347                                   Node* parm4, Node* parm5,
2348                                   Node* parm6, Node* parm7) {
2349   // Slow-path call
2350   bool is_leaf = !(flags & RC_NO_LEAF);
2351   bool has_io  = (!is_leaf && !(flags & RC_NO_IO));
2352   if (call_name == NULL) {
2353     assert(!is_leaf, "must supply name for leaf");
2354     call_name = OptoRuntime::stub_name(call_addr);
2355   }
2356   CallNode* call;
2357   if (!is_leaf) {
2358     call = new(C) CallStaticJavaNode(call_type, call_addr, call_name,
2359                                            bci(), adr_type);
2360   } else if (flags & RC_NO_FP) {
2361     call = new(C) CallLeafNoFPNode(call_type, call_addr, call_name, adr_type);
2362   } else {
2363     call = new(C) CallLeafNode(call_type, call_addr, call_name, adr_type);
2364   }
2365 
2366   // The following is similar to set_edges_for_java_call,
2367   // except that the memory effects of the call are restricted to AliasIdxRaw.
2368 
2369   // Slow path call has no side-effects, uses few values
2370   bool wide_in  = !(flags & RC_NARROW_MEM);
2371   bool wide_out = (C->get_alias_index(adr_type) == Compile::AliasIdxBot);
2372 
2373   Node* prev_mem = NULL;
2374   if (wide_in) {
2375     prev_mem = set_predefined_input_for_runtime_call(call);
2376   } else {
2377     assert(!wide_out, "narrow in => narrow out");
2378     Node* narrow_mem = memory(adr_type);
2379     prev_mem = reset_memory();
2380     map()->set_memory(narrow_mem);
2381     set_predefined_input_for_runtime_call(call);
2382   }
2383 
2384   // Hook each parm in order.  Stop looking at the first NULL.
2385   if (parm0 != NULL) { call->init_req(TypeFunc::Parms+0, parm0);
2386   if (parm1 != NULL) { call->init_req(TypeFunc::Parms+1, parm1);
2387   if (parm2 != NULL) { call->init_req(TypeFunc::Parms+2, parm2);
2388   if (parm3 != NULL) { call->init_req(TypeFunc::Parms+3, parm3);
2389   if (parm4 != NULL) { call->init_req(TypeFunc::Parms+4, parm4);
2390   if (parm5 != NULL) { call->init_req(TypeFunc::Parms+5, parm5);
2391   if (parm6 != NULL) { call->init_req(TypeFunc::Parms+6, parm6);
2392   if (parm7 != NULL) { call->init_req(TypeFunc::Parms+7, parm7);
2393     /* close each nested if ===> */  } } } } } } } }
2394   assert(call->in(call->req()-1) != NULL, "must initialize all parms");
2395 
2396   if (!is_leaf) {
2397     // Non-leaves can block and take safepoints:
2398     add_safepoint_edges(call, ((flags & RC_MUST_THROW) != 0));
2399   }
2400   // Non-leaves can throw exceptions:
2401   if (has_io) {
2402     call->set_req(TypeFunc::I_O, i_o());
2403   }
2404 
2405   if (flags & RC_UNCOMMON) {
2406     // Set the count to a tiny probability.  Cf. Estimate_Block_Frequency.
2407     // (An "if" probability corresponds roughly to an unconditional count.
2408     // Sort of.)
2409     call->set_cnt(PROB_UNLIKELY_MAG(4));
2410   }
2411 
2412   Node* c = _gvn.transform(call);
2413   assert(c == call, "cannot disappear");
2414 
2415   if (wide_out) {
2416     // Slow path call has full side-effects.
2417     set_predefined_output_for_runtime_call(call);
2418   } else {
2419     // Slow path call has few side-effects, and/or sets few values.
2420     set_predefined_output_for_runtime_call(call, prev_mem, adr_type);
2421   }
2422 
2423   if (has_io) {
2424     set_i_o(_gvn.transform(new (C) ProjNode(call, TypeFunc::I_O)));
2425   }
2426   return call;
2427 
2428 }
2429 
2430 //------------------------------merge_memory-----------------------------------
2431 // Merge memory from one path into the current memory state.
2432 void GraphKit::merge_memory(Node* new_mem, Node* region, int new_path) {
2433   for (MergeMemStream mms(merged_memory(), new_mem->as_MergeMem()); mms.next_non_empty2(); ) {
2434     Node* old_slice = mms.force_memory();
2435     Node* new_slice = mms.memory2();
2436     if (old_slice != new_slice) {
2437       PhiNode* phi;
2438       if (new_slice->is_Phi() && new_slice->as_Phi()->region() == region) {
2439         phi = new_slice->as_Phi();
2440         #ifdef ASSERT
2441         if (old_slice->is_Phi() && old_slice->as_Phi()->region() == region)
2442           old_slice = old_slice->in(new_path);
2443         // Caller is responsible for ensuring that any pre-existing
2444         // phis are already aware of old memory.
2445         int old_path = (new_path > 1) ? 1 : 2;  // choose old_path != new_path
2446         assert(phi->in(old_path) == old_slice, "pre-existing phis OK");
2447         #endif
2448         mms.set_memory(phi);
2449       } else {
2450         phi = PhiNode::make(region, old_slice, Type::MEMORY, mms.adr_type(C));
2451         _gvn.set_type(phi, Type::MEMORY);
2452         phi->set_req(new_path, new_slice);
2453         mms.set_memory(_gvn.transform(phi));  // assume it is complete
2454       }
2455     }
2456   }
2457 }
2458 
2459 //------------------------------make_slow_call_ex------------------------------
2460 // Make the exception handler hookups for the slow call
2461 void GraphKit::make_slow_call_ex(Node* call, ciInstanceKlass* ex_klass, bool separate_io_proj) {
2462   if (stopped())  return;
2463 
2464   // Make a catch node with just two handlers:  fall-through and catch-all
2465   Node* i_o  = _gvn.transform( new (C) ProjNode(call, TypeFunc::I_O, separate_io_proj) );
2466   Node* catc = _gvn.transform( new (C) CatchNode(control(), i_o, 2) );
2467   Node* norm = _gvn.transform( new (C) CatchProjNode(catc, CatchProjNode::fall_through_index, CatchProjNode::no_handler_bci) );
2468   Node* excp = _gvn.transform( new (C) CatchProjNode(catc, CatchProjNode::catch_all_index,    CatchProjNode::no_handler_bci) );
2469 
2470   { PreserveJVMState pjvms(this);
2471     set_control(excp);
2472     set_i_o(i_o);
2473 
2474     if (excp != top()) {
2475       // Create an exception state also.
2476       // Use an exact type if the caller has specified a specific exception.
2477       const Type* ex_type = TypeOopPtr::make_from_klass_unique(ex_klass)->cast_to_ptr_type(TypePtr::NotNull);
2478       Node*       ex_oop  = new (C) CreateExNode(ex_type, control(), i_o);
2479       add_exception_state(make_exception_state(_gvn.transform(ex_oop)));
2480     }
2481   }
2482 
2483   // Get the no-exception control from the CatchNode.
2484   set_control(norm);
2485 }
2486 
2487 
2488 //-------------------------------gen_subtype_check-----------------------------
2489 // Generate a subtyping check.  Takes as input the subtype and supertype.
2490 // Returns 2 values: sets the default control() to the true path and returns
2491 // the false path.  Only reads invariant memory; sets no (visible) memory.
2492 // The PartialSubtypeCheckNode sets the hidden 1-word cache in the encoding
2493 // but that's not exposed to the optimizer.  This call also doesn't take in an
2494 // Object; if you wish to check an Object you need to load the Object's class
2495 // prior to coming here.
2496 Node* GraphKit::gen_subtype_check(Node* subklass, Node* superklass) {
2497   // Fast check for identical types, perhaps identical constants.
2498   // The types can even be identical non-constants, in cases
2499   // involving Array.newInstance, Object.clone, etc.
2500   if (subklass == superklass)
2501     return top();             // false path is dead; no test needed.
2502 
2503   if (_gvn.type(superklass)->singleton()) {
2504     ciKlass* superk = _gvn.type(superklass)->is_klassptr()->klass();
2505     ciKlass* subk   = _gvn.type(subklass)->is_klassptr()->klass();
2506 
2507     // In the common case of an exact superklass, try to fold up the
2508     // test before generating code.  You may ask, why not just generate
2509     // the code and then let it fold up?  The answer is that the generated
2510     // code will necessarily include null checks, which do not always
2511     // completely fold away.  If they are also needless, then they turn
2512     // into a performance loss.  Example:
2513     //    Foo[] fa = blah(); Foo x = fa[0]; fa[1] = x;
2514     // Here, the type of 'fa' is often exact, so the store check
2515     // of fa[1]=x will fold up, without testing the nullness of x.
2516     switch (static_subtype_check(superk, subk)) {
2517     case SSC_always_false:
2518       {
2519         Node* always_fail = control();
2520         set_control(top());
2521         return always_fail;
2522       }
2523     case SSC_always_true:
2524       return top();
2525     case SSC_easy_test:
2526       {
2527         // Just do a direct pointer compare and be done.
2528         Node* cmp = _gvn.transform( new(C) CmpPNode(subklass, superklass) );
2529         Node* bol = _gvn.transform( new(C) BoolNode(cmp, BoolTest::eq) );
2530         IfNode* iff = create_and_xform_if(control(), bol, PROB_STATIC_FREQUENT, COUNT_UNKNOWN);
2531         set_control( _gvn.transform( new(C) IfTrueNode (iff) ) );
2532         return       _gvn.transform( new(C) IfFalseNode(iff) );
2533       }
2534     case SSC_full_test:
2535       break;
2536     default:
2537       ShouldNotReachHere();
2538     }
2539   }
2540 
2541   // %%% Possible further optimization:  Even if the superklass is not exact,
2542   // if the subklass is the unique subtype of the superklass, the check
2543   // will always succeed.  We could leave a dependency behind to ensure this.
2544 
2545   // First load the super-klass's check-offset
2546   Node *p1 = basic_plus_adr( superklass, superklass, in_bytes(Klass::super_check_offset_offset()) );
2547   Node *chk_off = _gvn.transform(new (C) LoadINode(NULL, memory(p1), p1, _gvn.type(p1)->is_ptr(),
2548                                                    TypeInt::INT, MemNode::unordered));
2549   int cacheoff_con = in_bytes(Klass::secondary_super_cache_offset());
2550   bool might_be_cache = (find_int_con(chk_off, cacheoff_con) == cacheoff_con);
2551 
2552   // Load from the sub-klass's super-class display list, or a 1-word cache of
2553   // the secondary superclass list, or a failing value with a sentinel offset
2554   // if the super-klass is an interface or exceptionally deep in the Java
2555   // hierarchy and we have to scan the secondary superclass list the hard way.
2556   // Worst-case type is a little odd: NULL is allowed as a result (usually
2557   // klass loads can never produce a NULL).
2558   Node *chk_off_X = ConvI2X(chk_off);
2559   Node *p2 = _gvn.transform( new (C) AddPNode(subklass,subklass,chk_off_X) );
2560   // For some types like interfaces the following loadKlass is from a 1-word
2561   // cache which is mutable so can't use immutable memory.  Other
2562   // types load from the super-class display table which is immutable.
2563   Node *kmem = might_be_cache ? memory(p2) : immutable_memory();
2564   Node *nkls = _gvn.transform( LoadKlassNode::make( _gvn, kmem, p2, _gvn.type(p2)->is_ptr(), TypeKlassPtr::OBJECT_OR_NULL ) );
2565 
2566   // Compile speed common case: ARE a subtype and we canNOT fail
2567   if( superklass == nkls )
2568     return top();             // false path is dead; no test needed.
2569 
2570   // See if we get an immediate positive hit.  Happens roughly 83% of the
2571   // time.  Test to see if the value loaded just previously from the subklass
2572   // is exactly the superklass.
2573   Node *cmp1 = _gvn.transform( new (C) CmpPNode( superklass, nkls ) );
2574   Node *bol1 = _gvn.transform( new (C) BoolNode( cmp1, BoolTest::eq ) );
2575   IfNode *iff1 = create_and_xform_if( control(), bol1, PROB_LIKELY(0.83f), COUNT_UNKNOWN );
2576   Node *iftrue1 = _gvn.transform( new (C) IfTrueNode ( iff1 ) );
2577   set_control(    _gvn.transform( new (C) IfFalseNode( iff1 ) ) );
2578 
2579   // Compile speed common case: Check for being deterministic right now.  If
2580   // chk_off is a constant and not equal to cacheoff then we are NOT a
2581   // subklass.  In this case we need exactly the 1 test above and we can
2582   // return those results immediately.
2583   if (!might_be_cache) {
2584     Node* not_subtype_ctrl = control();
2585     set_control(iftrue1); // We need exactly the 1 test above
2586     return not_subtype_ctrl;
2587   }
2588 
2589   // Gather the various success & failures here
2590   RegionNode *r_ok_subtype = new (C) RegionNode(4);
2591   record_for_igvn(r_ok_subtype);
2592   RegionNode *r_not_subtype = new (C) RegionNode(3);
2593   record_for_igvn(r_not_subtype);
2594 
2595   r_ok_subtype->init_req(1, iftrue1);
2596 
2597   // Check for immediate negative hit.  Happens roughly 11% of the time (which
2598   // is roughly 63% of the remaining cases).  Test to see if the loaded
2599   // check-offset points into the subklass display list or the 1-element
2600   // cache.  If it points to the display (and NOT the cache) and the display
2601   // missed then it's not a subtype.
2602   Node *cacheoff = _gvn.intcon(cacheoff_con);
2603   Node *cmp2 = _gvn.transform( new (C) CmpINode( chk_off, cacheoff ) );
2604   Node *bol2 = _gvn.transform( new (C) BoolNode( cmp2, BoolTest::ne ) );
2605   IfNode *iff2 = create_and_xform_if( control(), bol2, PROB_LIKELY(0.63f), COUNT_UNKNOWN );
2606   r_not_subtype->init_req(1, _gvn.transform( new (C) IfTrueNode (iff2) ) );
2607   set_control(                _gvn.transform( new (C) IfFalseNode(iff2) ) );
2608 
2609   // Check for self.  Very rare to get here, but it is taken 1/3 the time.
2610   // No performance impact (too rare) but allows sharing of secondary arrays
2611   // which has some footprint reduction.
2612   Node *cmp3 = _gvn.transform( new (C) CmpPNode( subklass, superklass ) );
2613   Node *bol3 = _gvn.transform( new (C) BoolNode( cmp3, BoolTest::eq ) );
2614   IfNode *iff3 = create_and_xform_if( control(), bol3, PROB_LIKELY(0.36f), COUNT_UNKNOWN );
2615   r_ok_subtype->init_req(2, _gvn.transform( new (C) IfTrueNode ( iff3 ) ) );
2616   set_control(               _gvn.transform( new (C) IfFalseNode( iff3 ) ) );
2617 
2618   // -- Roads not taken here: --
2619   // We could also have chosen to perform the self-check at the beginning
2620   // of this code sequence, as the assembler does.  This would not pay off
2621   // the same way, since the optimizer, unlike the assembler, can perform
2622   // static type analysis to fold away many successful self-checks.
2623   // Non-foldable self checks work better here in second position, because
2624   // the initial primary superclass check subsumes a self-check for most
2625   // types.  An exception would be a secondary type like array-of-interface,
2626   // which does not appear in its own primary supertype display.
2627   // Finally, we could have chosen to move the self-check into the
2628   // PartialSubtypeCheckNode, and from there out-of-line in a platform
2629   // dependent manner.  But it is worthwhile to have the check here,
2630   // where it can be perhaps be optimized.  The cost in code space is
2631   // small (register compare, branch).
2632 
2633   // Now do a linear scan of the secondary super-klass array.  Again, no real
2634   // performance impact (too rare) but it's gotta be done.
2635   // Since the code is rarely used, there is no penalty for moving it
2636   // out of line, and it can only improve I-cache density.
2637   // The decision to inline or out-of-line this final check is platform
2638   // dependent, and is found in the AD file definition of PartialSubtypeCheck.
2639   Node* psc = _gvn.transform(
2640     new (C) PartialSubtypeCheckNode(control(), subklass, superklass) );
2641 
2642   Node *cmp4 = _gvn.transform( new (C) CmpPNode( psc, null() ) );
2643   Node *bol4 = _gvn.transform( new (C) BoolNode( cmp4, BoolTest::ne ) );
2644   IfNode *iff4 = create_and_xform_if( control(), bol4, PROB_FAIR, COUNT_UNKNOWN );
2645   r_not_subtype->init_req(2, _gvn.transform( new (C) IfTrueNode (iff4) ) );
2646   r_ok_subtype ->init_req(3, _gvn.transform( new (C) IfFalseNode(iff4) ) );
2647 
2648   // Return false path; set default control to true path.
2649   set_control( _gvn.transform(r_ok_subtype) );
2650   return _gvn.transform(r_not_subtype);
2651 }
2652 
2653 //----------------------------static_subtype_check-----------------------------
2654 // Shortcut important common cases when superklass is exact:
2655 // (0) superklass is java.lang.Object (can occur in reflective code)
2656 // (1) subklass is already limited to a subtype of superklass => always ok
2657 // (2) subklass does not overlap with superklass => always fail
2658 // (3) superklass has NO subtypes and we can check with a simple compare.
2659 int GraphKit::static_subtype_check(ciKlass* superk, ciKlass* subk) {
2660   if (StressReflectiveCode) {
2661     return SSC_full_test;       // Let caller generate the general case.
2662   }
2663 
2664   if (superk == env()->Object_klass()) {
2665     return SSC_always_true;     // (0) this test cannot fail
2666   }
2667 
2668   ciType* superelem = superk;
2669   if (superelem->is_array_klass())
2670     superelem = superelem->as_array_klass()->base_element_type();
2671 
2672   if (!subk->is_interface()) {  // cannot trust static interface types yet
2673     if (subk->is_subtype_of(superk)) {
2674       return SSC_always_true;   // (1) false path dead; no dynamic test needed
2675     }
2676     if (!(superelem->is_klass() && superelem->as_klass()->is_interface()) &&
2677         !superk->is_subtype_of(subk)) {
2678       return SSC_always_false;
2679     }
2680   }
2681 
2682   // If casting to an instance klass, it must have no subtypes
2683   if (superk->is_interface()) {
2684     // Cannot trust interfaces yet.
2685     // %%% S.B. superk->nof_implementors() == 1
2686   } else if (superelem->is_instance_klass()) {
2687     ciInstanceKlass* ik = superelem->as_instance_klass();
2688     if (!ik->has_subklass() && !ik->is_interface()) {
2689       if (!ik->is_final()) {
2690         // Add a dependency if there is a chance of a later subclass.
2691         C->dependencies()->assert_leaf_type(ik);
2692       }
2693       return SSC_easy_test;     // (3) caller can do a simple ptr comparison
2694     }
2695   } else {
2696     // A primitive array type has no subtypes.
2697     return SSC_easy_test;       // (3) caller can do a simple ptr comparison
2698   }
2699 
2700   return SSC_full_test;
2701 }
2702 
2703 // Profile-driven exact type check:
2704 Node* GraphKit::type_check_receiver(Node* receiver, ciKlass* klass,
2705                                     float prob,
2706                                     Node* *casted_receiver) {
2707   const TypeKlassPtr* tklass = TypeKlassPtr::make(klass);
2708   Node* recv_klass = load_object_klass(receiver);
2709   Node* want_klass = makecon(tklass);
2710   Node* cmp = _gvn.transform( new(C) CmpPNode(recv_klass, want_klass) );
2711   Node* bol = _gvn.transform( new(C) BoolNode(cmp, BoolTest::eq) );
2712   IfNode* iff = create_and_xform_if(control(), bol, prob, COUNT_UNKNOWN);
2713   set_control( _gvn.transform( new(C) IfTrueNode (iff) ));
2714   Node* fail = _gvn.transform( new(C) IfFalseNode(iff) );
2715 
2716   const TypeOopPtr* recv_xtype = tklass->as_instance_type();
2717   assert(recv_xtype->klass_is_exact(), "");
2718 
2719   // Subsume downstream occurrences of receiver with a cast to
2720   // recv_xtype, since now we know what the type will be.
2721   Node* cast = new(C) CheckCastPPNode(control(), receiver, recv_xtype);
2722   (*casted_receiver) = _gvn.transform(cast);
2723   // (User must make the replace_in_map call.)
2724 
2725   return fail;
2726 }
2727 
2728 
2729 //------------------------------seems_never_null-------------------------------
2730 // Use null_seen information if it is available from the profile.
2731 // If we see an unexpected null at a type check we record it and force a
2732 // recompile; the offending check will be recompiled to handle NULLs.
2733 // If we see several offending BCIs, then all checks in the
2734 // method will be recompiled.
2735 bool GraphKit::seems_never_null(Node* obj, ciProfileData* data) {
2736   if (UncommonNullCast               // Cutout for this technique
2737       && obj != null()               // And not the -Xcomp stupid case?
2738       && !too_many_traps(Deoptimization::Reason_null_check)
2739       ) {
2740     if (data == NULL)
2741       // Edge case:  no mature data.  Be optimistic here.
2742       return true;
2743     // If the profile has not seen a null, assume it won't happen.
2744     assert(java_bc() == Bytecodes::_checkcast ||
2745            java_bc() == Bytecodes::_instanceof ||
2746            java_bc() == Bytecodes::_aastore, "MDO must collect null_seen bit here");
2747     return !data->as_BitData()->null_seen();
2748   }
2749   return false;
2750 }
2751 
2752 //------------------------maybe_cast_profiled_receiver-------------------------
2753 // If the profile has seen exactly one type, narrow to exactly that type.
2754 // Subsequent type checks will always fold up.
2755 Node* GraphKit::maybe_cast_profiled_receiver(Node* not_null_obj,
2756                                              ciKlass* require_klass,
2757                                              ciKlass* spec_klass,
2758                                              bool safe_for_replace) {
2759   if (!UseTypeProfile || !TypeProfileCasts) return NULL;
2760 
2761   Deoptimization::DeoptReason reason = spec_klass == NULL ? Deoptimization::Reason_class_check : Deoptimization::Reason_speculate_class_check;
2762 
2763   // Make sure we haven't already deoptimized from this tactic.
2764   if (too_many_traps(reason))
2765     return NULL;
2766 
2767   // (No, this isn't a call, but it's enough like a virtual call
2768   // to use the same ciMethod accessor to get the profile info...)
2769   // If we have a speculative type use it instead of profiling (which
2770   // may not help us)
2771   ciKlass* exact_kls = spec_klass == NULL ? profile_has_unique_klass() : spec_klass;
2772   if (exact_kls != NULL) {// no cast failures here
2773     if (require_klass == NULL ||
2774         static_subtype_check(require_klass, exact_kls) == SSC_always_true) {
2775       // If we narrow the type to match what the type profile sees or
2776       // the speculative type, we can then remove the rest of the
2777       // cast.
2778       // This is a win, even if the exact_kls is very specific,
2779       // because downstream operations, such as method calls,
2780       // will often benefit from the sharper type.
2781       Node* exact_obj = not_null_obj; // will get updated in place...
2782       Node* slow_ctl  = type_check_receiver(exact_obj, exact_kls, 1.0,
2783                                             &exact_obj);
2784       { PreserveJVMState pjvms(this);
2785         set_control(slow_ctl);
2786         uncommon_trap(reason,
2787                       Deoptimization::Action_maybe_recompile);
2788       }
2789       if (safe_for_replace) {
2790         replace_in_map(not_null_obj, exact_obj);
2791       }
2792       return exact_obj;
2793     }
2794     // assert(ssc == SSC_always_true)... except maybe the profile lied to us.
2795   }
2796 
2797   return NULL;
2798 }
2799 
2800 /**
2801  * Cast obj to type and emit guard unless we had too many traps here
2802  * already
2803  *
2804  * @param obj       node being casted
2805  * @param type      type to cast the node to
2806  * @param not_null  true if we know node cannot be null
2807  */
2808 Node* GraphKit::maybe_cast_profiled_obj(Node* obj,
2809                                         ciKlass* type,
2810                                         bool not_null) {
2811   // type == NULL if profiling tells us this object is always null
2812   if (type != NULL) {
2813     Deoptimization::DeoptReason class_reason = Deoptimization::Reason_speculate_class_check;
2814     Deoptimization::DeoptReason null_reason = Deoptimization::Reason_null_check;
2815     if (!too_many_traps(null_reason) &&
2816         !too_many_traps(class_reason)) {
2817       Node* not_null_obj = NULL;
2818       // not_null is true if we know the object is not null and
2819       // there's no need for a null check
2820       if (!not_null) {
2821         Node* null_ctl = top();
2822         not_null_obj = null_check_oop(obj, &null_ctl, true, true);
2823         assert(null_ctl->is_top(), "no null control here");
2824       } else {
2825         not_null_obj = obj;
2826       }
2827 
2828       Node* exact_obj = not_null_obj;
2829       ciKlass* exact_kls = type;
2830       Node* slow_ctl  = type_check_receiver(exact_obj, exact_kls, 1.0,
2831                                             &exact_obj);
2832       {
2833         PreserveJVMState pjvms(this);
2834         set_control(slow_ctl);
2835         uncommon_trap(class_reason,
2836                       Deoptimization::Action_maybe_recompile);
2837       }
2838       replace_in_map(not_null_obj, exact_obj);
2839       obj = exact_obj;
2840     }
2841   } else {
2842     if (!too_many_traps(Deoptimization::Reason_null_assert)) {
2843       Node* exact_obj = null_assert(obj);
2844       replace_in_map(obj, exact_obj);
2845       obj = exact_obj;
2846     }
2847   }
2848   return obj;
2849 }
2850 
2851 //-------------------------------gen_instanceof--------------------------------
2852 // Generate an instance-of idiom.  Used by both the instance-of bytecode
2853 // and the reflective instance-of call.
2854 Node* GraphKit::gen_instanceof(Node* obj, Node* superklass, bool safe_for_replace) {
2855   kill_dead_locals();           // Benefit all the uncommon traps
2856   assert( !stopped(), "dead parse path should be checked in callers" );
2857   assert(!TypePtr::NULL_PTR->higher_equal(_gvn.type(superklass)->is_klassptr()),
2858          "must check for not-null not-dead klass in callers");
2859 
2860   // Make the merge point
2861   enum { _obj_path = 1, _fail_path, _null_path, PATH_LIMIT };
2862   RegionNode* region = new(C) RegionNode(PATH_LIMIT);
2863   Node*       phi    = new(C) PhiNode(region, TypeInt::BOOL);
2864   C->set_has_split_ifs(true); // Has chance for split-if optimization
2865 
2866   ciProfileData* data = NULL;
2867   if (java_bc() == Bytecodes::_instanceof) {  // Only for the bytecode
2868     data = method()->method_data()->bci_to_data(bci());
2869   }
2870   bool never_see_null = (ProfileDynamicTypes  // aggressive use of profile
2871                          && seems_never_null(obj, data));
2872 
2873   // Null check; get casted pointer; set region slot 3
2874   Node* null_ctl = top();
2875   Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null, safe_for_replace);
2876 
2877   // If not_null_obj is dead, only null-path is taken
2878   if (stopped()) {              // Doing instance-of on a NULL?
2879     set_control(null_ctl);
2880     return intcon(0);
2881   }
2882   region->init_req(_null_path, null_ctl);
2883   phi   ->init_req(_null_path, intcon(0)); // Set null path value
2884   if (null_ctl == top()) {
2885     // Do this eagerly, so that pattern matches like is_diamond_phi
2886     // will work even during parsing.
2887     assert(_null_path == PATH_LIMIT-1, "delete last");
2888     region->del_req(_null_path);
2889     phi   ->del_req(_null_path);
2890   }
2891 
2892   // Do we know the type check always succeed?
2893   bool known_statically = false;
2894   if (_gvn.type(superklass)->singleton()) {
2895     ciKlass* superk = _gvn.type(superklass)->is_klassptr()->klass();
2896     ciKlass* subk = _gvn.type(obj)->is_oopptr()->klass();
2897     if (subk != NULL && subk->is_loaded()) {
2898       int static_res = static_subtype_check(superk, subk);
2899       known_statically = (static_res == SSC_always_true || static_res == SSC_always_false);
2900     }
2901   }
2902 
2903   if (known_statically && UseTypeSpeculation) {
2904     // If we know the type check always succeeds then we don't use the
2905     // profiling data at this bytecode. Don't lose it, feed it to the
2906     // type system as a speculative type.
2907     not_null_obj = record_profiled_receiver_for_speculation(not_null_obj);
2908   } else {
2909     const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
2910     // We may not have profiling here or it may not help us. If we
2911     // have a speculative type use it to perform an exact cast.
2912     ciKlass* spec_obj_type = obj_type->speculative_type();
2913     if (spec_obj_type != NULL || (ProfileDynamicTypes && data != NULL)) {
2914       Node* cast_obj = maybe_cast_profiled_receiver(not_null_obj, NULL, spec_obj_type, safe_for_replace);
2915       if (stopped()) {            // Profile disagrees with this path.
2916         set_control(null_ctl);    // Null is the only remaining possibility.
2917         return intcon(0);
2918       }
2919       if (cast_obj != NULL) {
2920         not_null_obj = cast_obj;
2921       }
2922     }
2923   }
2924 
2925   // Load the object's klass
2926   Node* obj_klass = load_object_klass(not_null_obj);
2927 
2928   // Generate the subtype check
2929   Node* not_subtype_ctrl = gen_subtype_check(obj_klass, superklass);
2930 
2931   // Plug in the success path to the general merge in slot 1.
2932   region->init_req(_obj_path, control());
2933   phi   ->init_req(_obj_path, intcon(1));
2934 
2935   // Plug in the failing path to the general merge in slot 2.
2936   region->init_req(_fail_path, not_subtype_ctrl);
2937   phi   ->init_req(_fail_path, intcon(0));
2938 
2939   // Return final merged results
2940   set_control( _gvn.transform(region) );
2941   record_for_igvn(region);
2942   return _gvn.transform(phi);
2943 }
2944 
2945 //-------------------------------gen_checkcast---------------------------------
2946 // Generate a checkcast idiom.  Used by both the checkcast bytecode and the
2947 // array store bytecode.  Stack must be as-if BEFORE doing the bytecode so the
2948 // uncommon-trap paths work.  Adjust stack after this call.
2949 // If failure_control is supplied and not null, it is filled in with
2950 // the control edge for the cast failure.  Otherwise, an appropriate
2951 // uncommon trap or exception is thrown.
2952 Node* GraphKit::gen_checkcast(Node *obj, Node* superklass,
2953                               Node* *failure_control) {
2954   kill_dead_locals();           // Benefit all the uncommon traps
2955   const TypeKlassPtr *tk = _gvn.type(superklass)->is_klassptr();
2956   const Type *toop = TypeOopPtr::make_from_klass(tk->klass());
2957 
2958   // Fast cutout:  Check the case that the cast is vacuously true.
2959   // This detects the common cases where the test will short-circuit
2960   // away completely.  We do this before we perform the null check,
2961   // because if the test is going to turn into zero code, we don't
2962   // want a residual null check left around.  (Causes a slowdown,
2963   // for example, in some objArray manipulations, such as a[i]=a[j].)
2964   if (tk->singleton()) {
2965     const TypeOopPtr* objtp = _gvn.type(obj)->isa_oopptr();
2966     if (objtp != NULL && objtp->klass() != NULL) {
2967       switch (static_subtype_check(tk->klass(), objtp->klass())) {
2968       case SSC_always_true:
2969         // If we know the type check always succeed then we don't use
2970         // the profiling data at this bytecode. Don't lose it, feed it
2971         // to the type system as a speculative type.
2972         return record_profiled_receiver_for_speculation(obj);
2973       case SSC_always_false:
2974         // It needs a null check because a null will *pass* the cast check.
2975         // A non-null value will always produce an exception.
2976         return null_assert(obj);
2977       }
2978     }
2979   }
2980 
2981   ciProfileData* data = NULL;
2982   bool safe_for_replace = false;
2983   if (failure_control == NULL) {        // use MDO in regular case only
2984     assert(java_bc() == Bytecodes::_aastore ||
2985            java_bc() == Bytecodes::_checkcast,
2986            "interpreter profiles type checks only for these BCs");
2987     data = method()->method_data()->bci_to_data(bci());
2988     safe_for_replace = true;
2989   }
2990 
2991   // Make the merge point
2992   enum { _obj_path = 1, _null_path, PATH_LIMIT };
2993   RegionNode* region = new (C) RegionNode(PATH_LIMIT);
2994   Node*       phi    = new (C) PhiNode(region, toop);
2995   C->set_has_split_ifs(true); // Has chance for split-if optimization
2996 
2997   // Use null-cast information if it is available
2998   bool never_see_null = ((failure_control == NULL)  // regular case only
2999                          && seems_never_null(obj, data));
3000 
3001   // Null check; get casted pointer; set region slot 3
3002   Node* null_ctl = top();
3003   Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null, safe_for_replace);
3004 
3005   // If not_null_obj is dead, only null-path is taken
3006   if (stopped()) {              // Doing instance-of on a NULL?
3007     set_control(null_ctl);
3008     return null();
3009   }
3010   region->init_req(_null_path, null_ctl);
3011   phi   ->init_req(_null_path, null());  // Set null path value
3012   if (null_ctl == top()) {
3013     // Do this eagerly, so that pattern matches like is_diamond_phi
3014     // will work even during parsing.
3015     assert(_null_path == PATH_LIMIT-1, "delete last");
3016     region->del_req(_null_path);
3017     phi   ->del_req(_null_path);
3018   }
3019 
3020   Node* cast_obj = NULL;
3021   if (tk->klass_is_exact()) {
3022     // The following optimization tries to statically cast the speculative type of the object
3023     // (for example obtained during profiling) to the type of the superklass and then do a
3024     // dynamic check that the type of the object is what we expect. To work correctly
3025     // for checkcast and aastore the type of superklass should be exact.
3026     const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
3027     // We may not have profiling here or it may not help us. If we have
3028     // a speculative type use it to perform an exact cast.
3029     ciKlass* spec_obj_type = obj_type->speculative_type();
3030     if (spec_obj_type != NULL ||
3031         (data != NULL &&
3032          // Counter has never been decremented (due to cast failure).
3033          // ...This is a reasonable thing to expect.  It is true of
3034          // all casts inserted by javac to implement generic types.
3035          data->as_CounterData()->count() >= 0)) {
3036       cast_obj = maybe_cast_profiled_receiver(not_null_obj, tk->klass(), spec_obj_type, safe_for_replace);
3037       if (cast_obj != NULL) {
3038         if (failure_control != NULL) // failure is now impossible
3039           (*failure_control) = top();
3040         // adjust the type of the phi to the exact klass:
3041         phi->raise_bottom_type(_gvn.type(cast_obj)->meet_speculative(TypePtr::NULL_PTR));
3042       }
3043     }
3044   }
3045 
3046   if (cast_obj == NULL) {
3047     // Load the object's klass
3048     Node* obj_klass = load_object_klass(not_null_obj);
3049 
3050     // Generate the subtype check
3051     Node* not_subtype_ctrl = gen_subtype_check( obj_klass, superklass );
3052 
3053     // Plug in success path into the merge
3054     cast_obj = _gvn.transform(new (C) CheckCastPPNode(control(),
3055                                                          not_null_obj, toop));
3056     // Failure path ends in uncommon trap (or may be dead - failure impossible)
3057     if (failure_control == NULL) {
3058       if (not_subtype_ctrl != top()) { // If failure is possible
3059         PreserveJVMState pjvms(this);
3060         set_control(not_subtype_ctrl);
3061         builtin_throw(Deoptimization::Reason_class_check, obj_klass);
3062       }
3063     } else {
3064       (*failure_control) = not_subtype_ctrl;
3065     }
3066   }
3067 
3068   region->init_req(_obj_path, control());
3069   phi   ->init_req(_obj_path, cast_obj);
3070 
3071   // A merge of NULL or Casted-NotNull obj
3072   Node* res = _gvn.transform(phi);
3073 
3074   // Note I do NOT always 'replace_in_map(obj,result)' here.
3075   //  if( tk->klass()->can_be_primary_super()  )
3076     // This means that if I successfully store an Object into an array-of-String
3077     // I 'forget' that the Object is really now known to be a String.  I have to
3078     // do this because we don't have true union types for interfaces - if I store
3079     // a Baz into an array-of-Interface and then tell the optimizer it's an
3080     // Interface, I forget that it's also a Baz and cannot do Baz-like field
3081     // references to it.  FIX THIS WHEN UNION TYPES APPEAR!
3082   //  replace_in_map( obj, res );
3083 
3084   // Return final merged results
3085   set_control( _gvn.transform(region) );
3086   record_for_igvn(region);
3087   return res;
3088 }
3089 
3090 //------------------------------next_monitor-----------------------------------
3091 // What number should be given to the next monitor?
3092 int GraphKit::next_monitor() {
3093   int current = jvms()->monitor_depth()* C->sync_stack_slots();
3094   int next = current + C->sync_stack_slots();
3095   // Keep the toplevel high water mark current:
3096   if (C->fixed_slots() < next)  C->set_fixed_slots(next);
3097   return current;
3098 }
3099 
3100 //------------------------------insert_mem_bar---------------------------------
3101 // Memory barrier to avoid floating things around
3102 // The membar serves as a pinch point between both control and all memory slices.
3103 Node* GraphKit::insert_mem_bar(int opcode, Node* precedent) {
3104   MemBarNode* mb = MemBarNode::make(C, opcode, Compile::AliasIdxBot, precedent);
3105   mb->init_req(TypeFunc::Control, control());
3106   mb->init_req(TypeFunc::Memory,  reset_memory());
3107   Node* membar = _gvn.transform(mb);
3108   set_control(_gvn.transform(new (C) ProjNode(membar, TypeFunc::Control)));
3109   set_all_memory_call(membar);
3110   return membar;
3111 }
3112 
3113 //-------------------------insert_mem_bar_volatile----------------------------
3114 // Memory barrier to avoid floating things around
3115 // The membar serves as a pinch point between both control and memory(alias_idx).
3116 // If you want to make a pinch point on all memory slices, do not use this
3117 // function (even with AliasIdxBot); use insert_mem_bar() instead.
3118 Node* GraphKit::insert_mem_bar_volatile(int opcode, int alias_idx, Node* precedent) {
3119   // When Parse::do_put_xxx updates a volatile field, it appends a series
3120   // of MemBarVolatile nodes, one for *each* volatile field alias category.
3121   // The first membar is on the same memory slice as the field store opcode.
3122   // This forces the membar to follow the store.  (Bug 6500685 broke this.)
3123   // All the other membars (for other volatile slices, including AliasIdxBot,
3124   // which stands for all unknown volatile slices) are control-dependent
3125   // on the first membar.  This prevents later volatile loads or stores
3126   // from sliding up past the just-emitted store.
3127 
3128   MemBarNode* mb = MemBarNode::make(C, opcode, alias_idx, precedent);
3129   mb->set_req(TypeFunc::Control,control());
3130   if (alias_idx == Compile::AliasIdxBot) {
3131     mb->set_req(TypeFunc::Memory, merged_memory()->base_memory());
3132   } else {
3133     assert(!(opcode == Op_Initialize && alias_idx != Compile::AliasIdxRaw), "fix caller");
3134     mb->set_req(TypeFunc::Memory, memory(alias_idx));
3135   }
3136   Node* membar = _gvn.transform(mb);
3137   set_control(_gvn.transform(new (C) ProjNode(membar, TypeFunc::Control)));
3138   if (alias_idx == Compile::AliasIdxBot) {
3139     merged_memory()->set_base_memory(_gvn.transform(new (C) ProjNode(membar, TypeFunc::Memory)));
3140   } else {
3141     set_memory(_gvn.transform(new (C) ProjNode(membar, TypeFunc::Memory)),alias_idx);
3142   }
3143   return membar;
3144 }
3145 
3146 //------------------------------shared_lock------------------------------------
3147 // Emit locking code.
3148 FastLockNode* GraphKit::shared_lock(Node* obj) {
3149   // bci is either a monitorenter bc or InvocationEntryBci
3150   // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
3151   assert(SynchronizationEntryBCI == InvocationEntryBci, "");
3152 
3153   if( !GenerateSynchronizationCode )
3154     return NULL;                // Not locking things?
3155   if (stopped())                // Dead monitor?
3156     return NULL;
3157 
3158   assert(dead_locals_are_killed(), "should kill locals before sync. point");
3159 
3160   // Box the stack location
3161   Node* box = _gvn.transform(new (C) BoxLockNode(next_monitor()));
3162   Node* mem = reset_memory();
3163 
3164   FastLockNode * flock = _gvn.transform(new (C) FastLockNode(0, obj, box) )->as_FastLock();
3165   if (UseBiasedLocking && PrintPreciseBiasedLockingStatistics) {
3166     // Create the counters for this fast lock.
3167     flock->create_lock_counter(sync_jvms()); // sync_jvms used to get current bci
3168   }
3169 
3170   // Create the rtm counters for this fast lock if needed.
3171   flock->create_rtm_lock_counter(sync_jvms()); // sync_jvms used to get current bci
3172 
3173   // Add monitor to debug info for the slow path.  If we block inside the
3174   // slow path and de-opt, we need the monitor hanging around
3175   map()->push_monitor( flock );
3176 
3177   const TypeFunc *tf = LockNode::lock_type();
3178   LockNode *lock = new (C) LockNode(C, tf);
3179 
3180   lock->init_req( TypeFunc::Control, control() );
3181   lock->init_req( TypeFunc::Memory , mem );
3182   lock->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
3183   lock->init_req( TypeFunc::FramePtr, frameptr() );
3184   lock->init_req( TypeFunc::ReturnAdr, top() );
3185 
3186   lock->init_req(TypeFunc::Parms + 0, obj);
3187   lock->init_req(TypeFunc::Parms + 1, box);
3188   lock->init_req(TypeFunc::Parms + 2, flock);
3189   add_safepoint_edges(lock);
3190 
3191   lock = _gvn.transform( lock )->as_Lock();
3192 
3193   // lock has no side-effects, sets few values
3194   set_predefined_output_for_runtime_call(lock, mem, TypeRawPtr::BOTTOM);
3195 
3196   insert_mem_bar(Op_MemBarAcquireLock);
3197 
3198   // Add this to the worklist so that the lock can be eliminated
3199   record_for_igvn(lock);
3200 
3201 #ifndef PRODUCT
3202   if (PrintLockStatistics) {
3203     // Update the counter for this lock.  Don't bother using an atomic
3204     // operation since we don't require absolute accuracy.
3205     lock->create_lock_counter(map()->jvms());
3206     increment_counter(lock->counter()->addr());
3207   }
3208 #endif
3209 
3210   return flock;
3211 }
3212 
3213 
3214 //------------------------------shared_unlock----------------------------------
3215 // Emit unlocking code.
3216 void GraphKit::shared_unlock(Node* box, Node* obj) {
3217   // bci is either a monitorenter bc or InvocationEntryBci
3218   // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
3219   assert(SynchronizationEntryBCI == InvocationEntryBci, "");
3220 
3221   if( !GenerateSynchronizationCode )
3222     return;
3223   if (stopped()) {               // Dead monitor?
3224     map()->pop_monitor();        // Kill monitor from debug info
3225     return;
3226   }
3227 
3228   // Memory barrier to avoid floating things down past the locked region
3229   insert_mem_bar(Op_MemBarReleaseLock);
3230 
3231   const TypeFunc *tf = OptoRuntime::complete_monitor_exit_Type();
3232   UnlockNode *unlock = new (C) UnlockNode(C, tf);
3233   uint raw_idx = Compile::AliasIdxRaw;
3234   unlock->init_req( TypeFunc::Control, control() );
3235   unlock->init_req( TypeFunc::Memory , memory(raw_idx) );
3236   unlock->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
3237   unlock->init_req( TypeFunc::FramePtr, frameptr() );
3238   unlock->init_req( TypeFunc::ReturnAdr, top() );
3239 
3240   unlock->init_req(TypeFunc::Parms + 0, obj);
3241   unlock->init_req(TypeFunc::Parms + 1, box);
3242   unlock = _gvn.transform(unlock)->as_Unlock();
3243 
3244   Node* mem = reset_memory();
3245 
3246   // unlock has no side-effects, sets few values
3247   set_predefined_output_for_runtime_call(unlock, mem, TypeRawPtr::BOTTOM);
3248 
3249   // Kill monitor from debug info
3250   map()->pop_monitor( );
3251 }
3252 
3253 //-------------------------------get_layout_helper-----------------------------
3254 // If the given klass is a constant or known to be an array,
3255 // fetch the constant layout helper value into constant_value
3256 // and return (Node*)NULL.  Otherwise, load the non-constant
3257 // layout helper value, and return the node which represents it.
3258 // This two-faced routine is useful because allocation sites
3259 // almost always feature constant types.
3260 Node* GraphKit::get_layout_helper(Node* klass_node, jint& constant_value) {
3261   const TypeKlassPtr* inst_klass = _gvn.type(klass_node)->isa_klassptr();
3262   if (!StressReflectiveCode && inst_klass != NULL) {
3263     ciKlass* klass = inst_klass->klass();
3264     bool    xklass = inst_klass->klass_is_exact();
3265     if (xklass || klass->is_array_klass()) {
3266       jint lhelper = klass->layout_helper();
3267       if (lhelper != Klass::_lh_neutral_value) {
3268         constant_value = lhelper;
3269         return (Node*) NULL;
3270       }
3271     }
3272   }
3273   constant_value = Klass::_lh_neutral_value;  // put in a known value
3274   Node* lhp = basic_plus_adr(klass_node, klass_node, in_bytes(Klass::layout_helper_offset()));
3275   return make_load(NULL, lhp, TypeInt::INT, T_INT, MemNode::unordered);
3276 }
3277 
3278 // We just put in an allocate/initialize with a big raw-memory effect.
3279 // Hook selected additional alias categories on the initialization.
3280 static void hook_memory_on_init(GraphKit& kit, int alias_idx,
3281                                 MergeMemNode* init_in_merge,
3282                                 Node* init_out_raw) {
3283   DEBUG_ONLY(Node* init_in_raw = init_in_merge->base_memory());
3284   assert(init_in_merge->memory_at(alias_idx) == init_in_raw, "");
3285 
3286   Node* prevmem = kit.memory(alias_idx);
3287   init_in_merge->set_memory_at(alias_idx, prevmem);
3288   kit.set_memory(init_out_raw, alias_idx);
3289 }
3290 
3291 //---------------------------set_output_for_allocation-------------------------
3292 Node* GraphKit::set_output_for_allocation(AllocateNode* alloc,
3293                                           const TypeOopPtr* oop_type) {
3294   int rawidx = Compile::AliasIdxRaw;
3295   alloc->set_req( TypeFunc::FramePtr, frameptr() );
3296   add_safepoint_edges(alloc);
3297   Node* allocx = _gvn.transform(alloc);
3298   set_control( _gvn.transform(new (C) ProjNode(allocx, TypeFunc::Control) ) );
3299   // create memory projection for i_o
3300   set_memory ( _gvn.transform( new (C) ProjNode(allocx, TypeFunc::Memory, true) ), rawidx );
3301   make_slow_call_ex(allocx, env()->Throwable_klass(), true);
3302 
3303   // create a memory projection as for the normal control path
3304   Node* malloc = _gvn.transform(new (C) ProjNode(allocx, TypeFunc::Memory));
3305   set_memory(malloc, rawidx);
3306 
3307   // a normal slow-call doesn't change i_o, but an allocation does
3308   // we create a separate i_o projection for the normal control path
3309   set_i_o(_gvn.transform( new (C) ProjNode(allocx, TypeFunc::I_O, false) ) );
3310   Node* rawoop = _gvn.transform( new (C) ProjNode(allocx, TypeFunc::Parms) );
3311 
3312   // put in an initialization barrier
3313   InitializeNode* init = insert_mem_bar_volatile(Op_Initialize, rawidx,
3314                                                  rawoop)->as_Initialize();
3315   assert(alloc->initialization() == init,  "2-way macro link must work");
3316   assert(init ->allocation()     == alloc, "2-way macro link must work");
3317   {
3318     // Extract memory strands which may participate in the new object's
3319     // initialization, and source them from the new InitializeNode.
3320     // This will allow us to observe initializations when they occur,
3321     // and link them properly (as a group) to the InitializeNode.
3322     assert(init->in(InitializeNode::Memory) == malloc, "");
3323     MergeMemNode* minit_in = MergeMemNode::make(C, malloc);
3324     init->set_req(InitializeNode::Memory, minit_in);
3325     record_for_igvn(minit_in); // fold it up later, if possible
3326     Node* minit_out = memory(rawidx);
3327     assert(minit_out->is_Proj() && minit_out->in(0) == init, "");
3328     if (oop_type->isa_aryptr()) {
3329       const TypePtr* telemref = oop_type->add_offset(Type::OffsetBot);
3330       int            elemidx  = C->get_alias_index(telemref);
3331       hook_memory_on_init(*this, elemidx, minit_in, minit_out);
3332     } else if (oop_type->isa_instptr()) {
3333       ciInstanceKlass* ik = oop_type->klass()->as_instance_klass();
3334       for (int i = 0, len = ik->nof_nonstatic_fields(); i < len; i++) {
3335         ciField* field = ik->nonstatic_field_at(i);
3336         if (field->offset() >= TrackedInitializationLimit * HeapWordSize)
3337           continue;  // do not bother to track really large numbers of fields
3338         // Find (or create) the alias category for this field:
3339         int fieldidx = C->alias_type(field)->index();
3340         hook_memory_on_init(*this, fieldidx, minit_in, minit_out);
3341       }
3342     }
3343   }
3344 
3345   // Cast raw oop to the real thing...
3346   Node* javaoop = new (C) CheckCastPPNode(control(), rawoop, oop_type);
3347   javaoop = _gvn.transform(javaoop);
3348   C->set_recent_alloc(control(), javaoop);
3349   assert(just_allocated_object(control()) == javaoop, "just allocated");
3350 
3351 #ifdef ASSERT
3352   { // Verify that the AllocateNode::Ideal_allocation recognizers work:
3353     assert(AllocateNode::Ideal_allocation(rawoop, &_gvn) == alloc,
3354            "Ideal_allocation works");
3355     assert(AllocateNode::Ideal_allocation(javaoop, &_gvn) == alloc,
3356            "Ideal_allocation works");
3357     if (alloc->is_AllocateArray()) {
3358       assert(AllocateArrayNode::Ideal_array_allocation(rawoop, &_gvn) == alloc->as_AllocateArray(),
3359              "Ideal_allocation works");
3360       assert(AllocateArrayNode::Ideal_array_allocation(javaoop, &_gvn) == alloc->as_AllocateArray(),
3361              "Ideal_allocation works");
3362     } else {
3363       assert(alloc->in(AllocateNode::ALength)->is_top(), "no length, please");
3364     }
3365   }
3366 #endif //ASSERT
3367 
3368   return javaoop;
3369 }
3370 
3371 //---------------------------new_instance--------------------------------------
3372 // This routine takes a klass_node which may be constant (for a static type)
3373 // or may be non-constant (for reflective code).  It will work equally well
3374 // for either, and the graph will fold nicely if the optimizer later reduces
3375 // the type to a constant.
3376 // The optional arguments are for specialized use by intrinsics:
3377 //  - If 'extra_slow_test' if not null is an extra condition for the slow-path.
3378 //  - If 'return_size_val', report the the total object size to the caller.
3379 Node* GraphKit::new_instance(Node* klass_node,
3380                              Node* extra_slow_test,
3381                              Node* *return_size_val) {
3382   // Compute size in doublewords
3383   // The size is always an integral number of doublewords, represented
3384   // as a positive bytewise size stored in the klass's layout_helper.
3385   // The layout_helper also encodes (in a low bit) the need for a slow path.
3386   jint  layout_con = Klass::_lh_neutral_value;
3387   Node* layout_val = get_layout_helper(klass_node, layout_con);
3388   int   layout_is_con = (layout_val == NULL);
3389 
3390   if (extra_slow_test == NULL)  extra_slow_test = intcon(0);
3391   // Generate the initial go-slow test.  It's either ALWAYS (return a
3392   // Node for 1) or NEVER (return a NULL) or perhaps (in the reflective
3393   // case) a computed value derived from the layout_helper.
3394   Node* initial_slow_test = NULL;
3395   if (layout_is_con) {
3396     assert(!StressReflectiveCode, "stress mode does not use these paths");
3397     bool must_go_slow = Klass::layout_helper_needs_slow_path(layout_con);
3398     initial_slow_test = must_go_slow? intcon(1): extra_slow_test;
3399 
3400   } else {   // reflective case
3401     // This reflective path is used by Unsafe.allocateInstance.
3402     // (It may be stress-tested by specifying StressReflectiveCode.)
3403     // Basically, we want to get into the VM is there's an illegal argument.
3404     Node* bit = intcon(Klass::_lh_instance_slow_path_bit);
3405     initial_slow_test = _gvn.transform( new (C) AndINode(layout_val, bit) );
3406     if (extra_slow_test != intcon(0)) {
3407       initial_slow_test = _gvn.transform( new (C) OrINode(initial_slow_test, extra_slow_test) );
3408     }
3409     // (Macro-expander will further convert this to a Bool, if necessary.)
3410   }
3411 
3412   // Find the size in bytes.  This is easy; it's the layout_helper.
3413   // The size value must be valid even if the slow path is taken.
3414   Node* size = NULL;
3415   if (layout_is_con) {
3416     size = MakeConX(Klass::layout_helper_size_in_bytes(layout_con));
3417   } else {   // reflective case
3418     // This reflective path is used by clone and Unsafe.allocateInstance.
3419     size = ConvI2X(layout_val);
3420 
3421     // Clear the low bits to extract layout_helper_size_in_bytes:
3422     assert((int)Klass::_lh_instance_slow_path_bit < BytesPerLong, "clear bit");
3423     Node* mask = MakeConX(~ (intptr_t)right_n_bits(LogBytesPerLong));
3424     size = _gvn.transform( new (C) AndXNode(size, mask) );
3425   }
3426   if (return_size_val != NULL) {
3427     (*return_size_val) = size;
3428   }
3429 
3430   // This is a precise notnull oop of the klass.
3431   // (Actually, it need not be precise if this is a reflective allocation.)
3432   // It's what we cast the result to.
3433   const TypeKlassPtr* tklass = _gvn.type(klass_node)->isa_klassptr();
3434   if (!tklass)  tklass = TypeKlassPtr::OBJECT;
3435   const TypeOopPtr* oop_type = tklass->as_instance_type();
3436 
3437   // Now generate allocation code
3438 
3439   // The entire memory state is needed for slow path of the allocation
3440   // since GC and deoptimization can happened.
3441   Node *mem = reset_memory();
3442   set_all_memory(mem); // Create new memory state
3443 
3444   AllocateNode* alloc
3445     = new (C) AllocateNode(C, AllocateNode::alloc_type(Type::TOP),
3446                            control(), mem, i_o(),
3447                            size, klass_node,
3448                            initial_slow_test);
3449 
3450   return set_output_for_allocation(alloc, oop_type);
3451 }
3452 
3453 //-------------------------------new_array-------------------------------------
3454 // helper for both newarray and anewarray
3455 // The 'length' parameter is (obviously) the length of the array.
3456 // See comments on new_instance for the meaning of the other arguments.
3457 Node* GraphKit::new_array(Node* klass_node,     // array klass (maybe variable)
3458                           Node* length,         // number of array elements
3459                           int   nargs,          // number of arguments to push back for uncommon trap
3460                           Node* *return_size_val) {
3461   jint  layout_con = Klass::_lh_neutral_value;
3462   Node* layout_val = get_layout_helper(klass_node, layout_con);
3463   int   layout_is_con = (layout_val == NULL);
3464 
3465   if (!layout_is_con && !StressReflectiveCode &&
3466       !too_many_traps(Deoptimization::Reason_class_check)) {
3467     // This is a reflective array creation site.
3468     // Optimistically assume that it is a subtype of Object[],
3469     // so that we can fold up all the address arithmetic.
3470     layout_con = Klass::array_layout_helper(T_OBJECT);
3471     Node* cmp_lh = _gvn.transform( new(C) CmpINode(layout_val, intcon(layout_con)) );
3472     Node* bol_lh = _gvn.transform( new(C) BoolNode(cmp_lh, BoolTest::eq) );
3473     { BuildCutout unless(this, bol_lh, PROB_MAX);
3474       inc_sp(nargs);
3475       uncommon_trap(Deoptimization::Reason_class_check,
3476                     Deoptimization::Action_maybe_recompile);
3477     }
3478     layout_val = NULL;
3479     layout_is_con = true;
3480   }
3481 
3482   // Generate the initial go-slow test.  Make sure we do not overflow
3483   // if length is huge (near 2Gig) or negative!  We do not need
3484   // exact double-words here, just a close approximation of needed
3485   // double-words.  We can't add any offset or rounding bits, lest we
3486   // take a size -1 of bytes and make it positive.  Use an unsigned
3487   // compare, so negative sizes look hugely positive.
3488   int fast_size_limit = FastAllocateSizeLimit;
3489   if (layout_is_con) {
3490     assert(!StressReflectiveCode, "stress mode does not use these paths");
3491     // Increase the size limit if we have exact knowledge of array type.
3492     int log2_esize = Klass::layout_helper_log2_element_size(layout_con);
3493     fast_size_limit <<= (LogBytesPerLong - log2_esize);
3494   }
3495 
3496   Node* initial_slow_cmp  = _gvn.transform( new (C) CmpUNode( length, intcon( fast_size_limit ) ) );
3497   Node* initial_slow_test = _gvn.transform( new (C) BoolNode( initial_slow_cmp, BoolTest::gt ) );
3498   if (initial_slow_test->is_Bool()) {
3499     // Hide it behind a CMoveI, or else PhaseIdealLoop::split_up will get sick.
3500     initial_slow_test = initial_slow_test->as_Bool()->as_int_value(&_gvn);
3501   }
3502 
3503   // --- Size Computation ---
3504   // array_size = round_to_heap(array_header + (length << elem_shift));
3505   // where round_to_heap(x) == round_to(x, MinObjAlignmentInBytes)
3506   // and round_to(x, y) == ((x + y-1) & ~(y-1))
3507   // The rounding mask is strength-reduced, if possible.
3508   int round_mask = MinObjAlignmentInBytes - 1;
3509   Node* header_size = NULL;
3510   int   header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
3511   // (T_BYTE has the weakest alignment and size restrictions...)
3512   if (layout_is_con) {
3513     int       hsize  = Klass::layout_helper_header_size(layout_con);
3514     int       eshift = Klass::layout_helper_log2_element_size(layout_con);
3515     BasicType etype  = Klass::layout_helper_element_type(layout_con);
3516     if ((round_mask & ~right_n_bits(eshift)) == 0)
3517       round_mask = 0;  // strength-reduce it if it goes away completely
3518     assert((hsize & right_n_bits(eshift)) == 0, "hsize is pre-rounded");
3519     assert(header_size_min <= hsize, "generic minimum is smallest");
3520     header_size_min = hsize;
3521     header_size = intcon(hsize + round_mask);
3522   } else {
3523     Node* hss   = intcon(Klass::_lh_header_size_shift);
3524     Node* hsm   = intcon(Klass::_lh_header_size_mask);
3525     Node* hsize = _gvn.transform( new(C) URShiftINode(layout_val, hss) );
3526     hsize       = _gvn.transform( new(C) AndINode(hsize, hsm) );
3527     Node* mask  = intcon(round_mask);
3528     header_size = _gvn.transform( new(C) AddINode(hsize, mask) );
3529   }
3530 
3531   Node* elem_shift = NULL;
3532   if (layout_is_con) {
3533     int eshift = Klass::layout_helper_log2_element_size(layout_con);
3534     if (eshift != 0)
3535       elem_shift = intcon(eshift);
3536   } else {
3537     // There is no need to mask or shift this value.
3538     // The semantics of LShiftINode include an implicit mask to 0x1F.
3539     assert(Klass::_lh_log2_element_size_shift == 0, "use shift in place");
3540     elem_shift = layout_val;
3541   }
3542 
3543   // Transition to native address size for all offset calculations:
3544   Node* lengthx = ConvI2X(length);
3545   Node* headerx = ConvI2X(header_size);
3546 #ifdef _LP64
3547   { const TypeLong* tllen = _gvn.find_long_type(lengthx);
3548     if (tllen != NULL && tllen->_lo < 0) {
3549       // Add a manual constraint to a positive range.  Cf. array_element_address.
3550       jlong size_max = arrayOopDesc::max_array_length(T_BYTE);
3551       if (size_max > tllen->_hi)  size_max = tllen->_hi;
3552       const TypeLong* tlcon = TypeLong::make(CONST64(0), size_max, Type::WidenMin);
3553       lengthx = _gvn.transform( new (C) ConvI2LNode(length, tlcon));
3554     }
3555   }
3556 #endif
3557 
3558   // Combine header size (plus rounding) and body size.  Then round down.
3559   // This computation cannot overflow, because it is used only in two
3560   // places, one where the length is sharply limited, and the other
3561   // after a successful allocation.
3562   Node* abody = lengthx;
3563   if (elem_shift != NULL)
3564     abody     = _gvn.transform( new(C) LShiftXNode(lengthx, elem_shift) );
3565   Node* size  = _gvn.transform( new(C) AddXNode(headerx, abody) );
3566   if (round_mask != 0) {
3567     Node* mask = MakeConX(~round_mask);
3568     size       = _gvn.transform( new(C) AndXNode(size, mask) );
3569   }
3570   // else if round_mask == 0, the size computation is self-rounding
3571 
3572   if (return_size_val != NULL) {
3573     // This is the size
3574     (*return_size_val) = size;
3575   }
3576 
3577   // Now generate allocation code
3578 
3579   // The entire memory state is needed for slow path of the allocation
3580   // since GC and deoptimization can happened.
3581   Node *mem = reset_memory();
3582   set_all_memory(mem); // Create new memory state
3583 
3584   // Create the AllocateArrayNode and its result projections
3585   AllocateArrayNode* alloc
3586     = new (C) AllocateArrayNode(C, AllocateArrayNode::alloc_type(TypeInt::INT),
3587                                 control(), mem, i_o(),
3588                                 size, klass_node,
3589                                 initial_slow_test,
3590                                 length);
3591 
3592   // Cast to correct type.  Note that the klass_node may be constant or not,
3593   // and in the latter case the actual array type will be inexact also.
3594   // (This happens via a non-constant argument to inline_native_newArray.)
3595   // In any case, the value of klass_node provides the desired array type.
3596   const TypeInt* length_type = _gvn.find_int_type(length);
3597   const TypeOopPtr* ary_type = _gvn.type(klass_node)->is_klassptr()->as_instance_type();
3598   if (ary_type->isa_aryptr() && length_type != NULL) {
3599     // Try to get a better type than POS for the size
3600     ary_type = ary_type->is_aryptr()->cast_to_size(length_type);
3601   }
3602 
3603   Node* javaoop = set_output_for_allocation(alloc, ary_type);
3604 
3605   // Cast length on remaining path to be as narrow as possible
3606   if (map()->find_edge(length) >= 0) {
3607     Node* ccast = alloc->make_ideal_length(ary_type, &_gvn);
3608     if (ccast != length) {
3609       _gvn.set_type_bottom(ccast);
3610       record_for_igvn(ccast);
3611       replace_in_map(length, ccast);
3612     }
3613   }
3614 
3615   return javaoop;
3616 }
3617 
3618 // The following "Ideal_foo" functions are placed here because they recognize
3619 // the graph shapes created by the functions immediately above.
3620 
3621 //---------------------------Ideal_allocation----------------------------------
3622 // Given an oop pointer or raw pointer, see if it feeds from an AllocateNode.
3623 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase) {
3624   if (ptr == NULL) {     // reduce dumb test in callers
3625     return NULL;
3626   }
3627   if (ptr->is_CheckCastPP()) { // strip only one raw-to-oop cast
3628     ptr = ptr->in(1);
3629     if (ptr == NULL) return NULL;
3630   }
3631   // Return NULL for allocations with several casts:
3632   //   j.l.reflect.Array.newInstance(jobject, jint)
3633   //   Object.clone()
3634   // to keep more precise type from last cast.
3635   if (ptr->is_Proj()) {
3636     Node* allo = ptr->in(0);
3637     if (allo != NULL && allo->is_Allocate()) {
3638       return allo->as_Allocate();
3639     }
3640   }
3641   // Report failure to match.
3642   return NULL;
3643 }
3644 
3645 // Fancy version which also strips off an offset (and reports it to caller).
3646 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase,
3647                                              intptr_t& offset) {
3648   Node* base = AddPNode::Ideal_base_and_offset(ptr, phase, offset);
3649   if (base == NULL)  return NULL;
3650   return Ideal_allocation(base, phase);
3651 }
3652 
3653 // Trace Initialize <- Proj[Parm] <- Allocate
3654 AllocateNode* InitializeNode::allocation() {
3655   Node* rawoop = in(InitializeNode::RawAddress);
3656   if (rawoop->is_Proj()) {
3657     Node* alloc = rawoop->in(0);
3658     if (alloc->is_Allocate()) {
3659       return alloc->as_Allocate();
3660     }
3661   }
3662   return NULL;
3663 }
3664 
3665 // Trace Allocate -> Proj[Parm] -> Initialize
3666 InitializeNode* AllocateNode::initialization() {
3667   ProjNode* rawoop = proj_out(AllocateNode::RawAddress);
3668   if (rawoop == NULL)  return NULL;
3669   for (DUIterator_Fast imax, i = rawoop->fast_outs(imax); i < imax; i++) {
3670     Node* init = rawoop->fast_out(i);
3671     if (init->is_Initialize()) {
3672       assert(init->as_Initialize()->allocation() == this, "2-way link");
3673       return init->as_Initialize();
3674     }
3675   }
3676   return NULL;
3677 }
3678 
3679 //----------------------------- loop predicates ---------------------------
3680 
3681 //------------------------------add_predicate_impl----------------------------
3682 void GraphKit::add_predicate_impl(Deoptimization::DeoptReason reason, int nargs) {
3683   // Too many traps seen?
3684   if (too_many_traps(reason)) {
3685 #ifdef ASSERT
3686     if (TraceLoopPredicate) {
3687       int tc = C->trap_count(reason);
3688       tty->print("too many traps=%s tcount=%d in ",
3689                     Deoptimization::trap_reason_name(reason), tc);
3690       method()->print(); // which method has too many predicate traps
3691       tty->cr();
3692     }
3693 #endif
3694     // We cannot afford to take more traps here,
3695     // do not generate predicate.
3696     return;
3697   }
3698 
3699   Node *cont    = _gvn.intcon(1);
3700   Node* opq     = _gvn.transform(new (C) Opaque1Node(C, cont));
3701   Node *bol     = _gvn.transform(new (C) Conv2BNode(opq));
3702   IfNode* iff   = create_and_map_if(control(), bol, PROB_MAX, COUNT_UNKNOWN);
3703   Node* iffalse = _gvn.transform(new (C) IfFalseNode(iff));
3704   C->add_predicate_opaq(opq);
3705   {
3706     PreserveJVMState pjvms(this);
3707     set_control(iffalse);
3708     inc_sp(nargs);
3709     uncommon_trap(reason, Deoptimization::Action_maybe_recompile);
3710   }
3711   Node* iftrue = _gvn.transform(new (C) IfTrueNode(iff));
3712   set_control(iftrue);
3713 }
3714 
3715 //------------------------------add_predicate---------------------------------
3716 void GraphKit::add_predicate(int nargs) {
3717   if (UseLoopPredicate) {
3718     add_predicate_impl(Deoptimization::Reason_predicate, nargs);
3719   }
3720   // loop's limit check predicate should be near the loop.
3721   if (LoopLimitCheck) {
3722     add_predicate_impl(Deoptimization::Reason_loop_limit_check, nargs);
3723   }
3724 }
3725 
3726 //----------------------------- store barriers ----------------------------
3727 #define __ ideal.
3728 
3729 void GraphKit::sync_kit(IdealKit& ideal) {
3730   set_all_memory(__ merged_memory());
3731   set_i_o(__ i_o());
3732   set_control(__ ctrl());
3733 }
3734 
3735 void GraphKit::final_sync(IdealKit& ideal) {
3736   // Final sync IdealKit and graphKit.
3737   sync_kit(ideal);
3738 }
3739 
3740 // vanilla/CMS post barrier
3741 // Insert a write-barrier store.  This is to let generational GC work; we have
3742 // to flag all oop-stores before the next GC point.
3743 void GraphKit::write_barrier_post(Node* oop_store,
3744                                   Node* obj,
3745                                   Node* adr,
3746                                   uint  adr_idx,
3747                                   Node* val,
3748                                   bool use_precise) {
3749   // No store check needed if we're storing a NULL or an old object
3750   // (latter case is probably a string constant). The concurrent
3751   // mark sweep garbage collector, however, needs to have all nonNull
3752   // oop updates flagged via card-marks.
3753   if (val != NULL && val->is_Con()) {
3754     // must be either an oop or NULL
3755     const Type* t = val->bottom_type();
3756     if (t == TypePtr::NULL_PTR || t == Type::TOP)
3757       // stores of null never (?) need barriers
3758       return;
3759   }
3760 
3761   if (use_ReduceInitialCardMarks()
3762       && obj == just_allocated_object(control())) {
3763     // We can skip marks on a freshly-allocated object in Eden.
3764     // Keep this code in sync with new_store_pre_barrier() in runtime.cpp.
3765     // That routine informs GC to take appropriate compensating steps,
3766     // upon a slow-path allocation, so as to make this card-mark
3767     // elision safe.
3768     return;
3769   }
3770 
3771   if (!use_precise) {
3772     // All card marks for a (non-array) instance are in one place:
3773     adr = obj;
3774   }
3775   // (Else it's an array (or unknown), and we want more precise card marks.)
3776   assert(adr != NULL, "");
3777 
3778   IdealKit ideal(this, true);
3779 
3780   // Convert the pointer to an int prior to doing math on it
3781   Node* cast = __ CastPX(__ ctrl(), adr);
3782 
3783   // Divide by card size
3784   assert(Universe::heap()->barrier_set()->kind() == BarrierSet::CardTableModRef,
3785          "Only one we handle so far.");
3786   Node* card_offset = __ URShiftX( cast, __ ConI(CardTableModRefBS::card_shift) );
3787 
3788   // Combine card table base and card offset
3789   Node* card_adr = __ AddP(__ top(), byte_map_base_node(), card_offset );
3790 
3791   // Get the alias_index for raw card-mark memory
3792   int adr_type = Compile::AliasIdxRaw;
3793   Node*   zero = __ ConI(0); // Dirty card value
3794   BasicType bt = T_BYTE;
3795 
3796   if (UseCondCardMark) {
3797     // The classic GC reference write barrier is typically implemented
3798     // as a store into the global card mark table.  Unfortunately
3799     // unconditional stores can result in false sharing and excessive
3800     // coherence traffic as well as false transactional aborts.
3801     // UseCondCardMark enables MP "polite" conditional card mark
3802     // stores.  In theory we could relax the load from ctrl() to
3803     // no_ctrl, but that doesn't buy much latitude.
3804     Node* card_val = __ load( __ ctrl(), card_adr, TypeInt::BYTE, bt, adr_type);
3805     __ if_then(card_val, BoolTest::ne, zero);
3806   }
3807 
3808   // Smash zero into card
3809   if( !UseConcMarkSweepGC ) {
3810     __ store(__ ctrl(), card_adr, zero, bt, adr_type, MemNode::release);
3811   } else {
3812     // Specialized path for CM store barrier
3813     __ storeCM(__ ctrl(), card_adr, zero, oop_store, adr_idx, bt, adr_type);
3814   }
3815 
3816   if (UseCondCardMark) {
3817     __ end_if();
3818   }
3819 
3820   // Final sync IdealKit and GraphKit.
3821   final_sync(ideal);
3822 }
3823 
3824 // G1 pre/post barriers
3825 void GraphKit::g1_write_barrier_pre(bool do_load,
3826                                     Node* obj,
3827                                     Node* adr,
3828                                     uint alias_idx,
3829                                     Node* val,
3830                                     const TypeOopPtr* val_type,
3831                                     Node* pre_val,
3832                                     BasicType bt) {
3833 
3834   // Some sanity checks
3835   // Note: val is unused in this routine.
3836 
3837   if (do_load) {
3838     // We need to generate the load of the previous value
3839     assert(obj != NULL, "must have a base");
3840     assert(adr != NULL, "where are loading from?");
3841     assert(pre_val == NULL, "loaded already?");
3842     assert(val_type != NULL, "need a type");
3843   } else {
3844     // In this case both val_type and alias_idx are unused.
3845     assert(pre_val != NULL, "must be loaded already");
3846     // Nothing to be done if pre_val is null.
3847     if (pre_val->bottom_type() == TypePtr::NULL_PTR) return;
3848     assert(pre_val->bottom_type()->basic_type() == T_OBJECT, "or we shouldn't be here");
3849   }
3850   assert(bt == T_OBJECT, "or we shouldn't be here");
3851 
3852   IdealKit ideal(this, true);
3853 
3854   Node* tls = __ thread(); // ThreadLocalStorage
3855 
3856   Node* no_ctrl = NULL;
3857   Node* no_base = __ top();
3858   Node* zero  = __ ConI(0);
3859   Node* zeroX = __ ConX(0);
3860 
3861   float likely  = PROB_LIKELY(0.999);
3862   float unlikely  = PROB_UNLIKELY(0.999);
3863 
3864   BasicType active_type = in_bytes(PtrQueue::byte_width_of_active()) == 4 ? T_INT : T_BYTE;
3865   assert(in_bytes(PtrQueue::byte_width_of_active()) == 4 || in_bytes(PtrQueue::byte_width_of_active()) == 1, "flag width");
3866 
3867   // Offsets into the thread
3868   const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() +  // 648
3869                                           PtrQueue::byte_offset_of_active());
3870   const int index_offset   = in_bytes(JavaThread::satb_mark_queue_offset() +  // 656
3871                                           PtrQueue::byte_offset_of_index());
3872   const int buffer_offset  = in_bytes(JavaThread::satb_mark_queue_offset() +  // 652
3873                                           PtrQueue::byte_offset_of_buf());
3874 
3875   // Now the actual pointers into the thread
3876   Node* marking_adr = __ AddP(no_base, tls, __ ConX(marking_offset));
3877   Node* buffer_adr  = __ AddP(no_base, tls, __ ConX(buffer_offset));
3878   Node* index_adr   = __ AddP(no_base, tls, __ ConX(index_offset));
3879 
3880   // Now some of the values
3881   Node* marking = __ load(__ ctrl(), marking_adr, TypeInt::INT, active_type, Compile::AliasIdxRaw);
3882 
3883   // if (!marking)
3884   __ if_then(marking, BoolTest::ne, zero, unlikely); {
3885     BasicType index_bt = TypeX_X->basic_type();
3886     assert(sizeof(size_t) == type2aelembytes(index_bt), "Loading G1 PtrQueue::_index with wrong size.");
3887     Node* index   = __ load(__ ctrl(), index_adr, TypeX_X, index_bt, Compile::AliasIdxRaw);
3888 
3889     if (do_load) {
3890       // load original value
3891       // alias_idx correct??
3892       pre_val = __ load(__ ctrl(), adr, val_type, bt, alias_idx);
3893     }
3894 
3895     // if (pre_val != NULL)
3896     __ if_then(pre_val, BoolTest::ne, null()); {
3897       Node* buffer  = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
3898 
3899       // is the queue for this thread full?
3900       __ if_then(index, BoolTest::ne, zeroX, likely); {
3901 
3902         // decrement the index
3903         Node* next_index = _gvn.transform(new (C) SubXNode(index, __ ConX(sizeof(intptr_t))));
3904 
3905         // Now get the buffer location we will log the previous value into and store it
3906         Node *log_addr = __ AddP(no_base, buffer, next_index);
3907         __ store(__ ctrl(), log_addr, pre_val, T_OBJECT, Compile::AliasIdxRaw, MemNode::unordered);
3908         // update the index
3909         __ store(__ ctrl(), index_adr, next_index, index_bt, Compile::AliasIdxRaw, MemNode::unordered);
3910 
3911       } __ else_(); {
3912 
3913         // logging buffer is full, call the runtime
3914         const TypeFunc *tf = OptoRuntime::g1_wb_pre_Type();
3915         __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_pre), "g1_wb_pre", pre_val, tls);
3916       } __ end_if();  // (!index)
3917     } __ end_if();  // (pre_val != NULL)
3918   } __ end_if();  // (!marking)
3919 
3920   // Final sync IdealKit and GraphKit.
3921   final_sync(ideal);
3922 }
3923 
3924 //
3925 // Update the card table and add card address to the queue
3926 //
3927 void GraphKit::g1_mark_card(IdealKit& ideal,
3928                             Node* card_adr,
3929                             Node* oop_store,
3930                             uint oop_alias_idx,
3931                             Node* index,
3932                             Node* index_adr,
3933                             Node* buffer,
3934                             const TypeFunc* tf) {
3935 
3936   Node* zero  = __ ConI(0);
3937   Node* zeroX = __ ConX(0);
3938   Node* no_base = __ top();
3939   BasicType card_bt = T_BYTE;
3940   // Smash zero into card. MUST BE ORDERED WRT TO STORE
3941   __ storeCM(__ ctrl(), card_adr, zero, oop_store, oop_alias_idx, card_bt, Compile::AliasIdxRaw);
3942 
3943   //  Now do the queue work
3944   __ if_then(index, BoolTest::ne, zeroX); {
3945 
3946     Node* next_index = _gvn.transform(new (C) SubXNode(index, __ ConX(sizeof(intptr_t))));
3947     Node* log_addr = __ AddP(no_base, buffer, next_index);
3948 
3949     // Order, see storeCM.
3950     __ store(__ ctrl(), log_addr, card_adr, T_ADDRESS, Compile::AliasIdxRaw, MemNode::unordered);
3951     __ store(__ ctrl(), index_adr, next_index, TypeX_X->basic_type(), Compile::AliasIdxRaw, MemNode::unordered);
3952 
3953   } __ else_(); {
3954     __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_post), "g1_wb_post", card_adr, __ thread());
3955   } __ end_if();
3956 
3957 }
3958 
3959 void GraphKit::g1_write_barrier_post(Node* oop_store,
3960                                      Node* obj,
3961                                      Node* adr,
3962                                      uint alias_idx,
3963                                      Node* val,
3964                                      BasicType bt,
3965                                      bool use_precise) {
3966   // If we are writing a NULL then we need no post barrier
3967 
3968   if (val != NULL && val->is_Con() && val->bottom_type() == TypePtr::NULL_PTR) {
3969     // Must be NULL
3970     const Type* t = val->bottom_type();
3971     assert(t == Type::TOP || t == TypePtr::NULL_PTR, "must be NULL");
3972     // No post barrier if writing NULLx
3973     return;
3974   }
3975 
3976   if (!use_precise) {
3977     // All card marks for a (non-array) instance are in one place:
3978     adr = obj;
3979   }
3980   // (Else it's an array (or unknown), and we want more precise card marks.)
3981   assert(adr != NULL, "");
3982 
3983   IdealKit ideal(this, true);
3984 
3985   Node* tls = __ thread(); // ThreadLocalStorage
3986 
3987   Node* no_base = __ top();
3988   float likely  = PROB_LIKELY(0.999);
3989   float unlikely  = PROB_UNLIKELY(0.999);
3990   Node* young_card = __ ConI((jint)G1SATBCardTableModRefBS::g1_young_card_val());
3991   Node* dirty_card = __ ConI((jint)CardTableModRefBS::dirty_card_val());
3992   Node* zeroX = __ ConX(0);
3993 
3994   // Get the alias_index for raw card-mark memory
3995   const TypePtr* card_type = TypeRawPtr::BOTTOM;
3996 
3997   const TypeFunc *tf = OptoRuntime::g1_wb_post_Type();
3998 
3999   // Offsets into the thread
4000   const int index_offset  = in_bytes(JavaThread::dirty_card_queue_offset() +
4001                                      PtrQueue::byte_offset_of_index());
4002   const int buffer_offset = in_bytes(JavaThread::dirty_card_queue_offset() +
4003                                      PtrQueue::byte_offset_of_buf());
4004 
4005   // Pointers into the thread
4006 
4007   Node* buffer_adr = __ AddP(no_base, tls, __ ConX(buffer_offset));
4008   Node* index_adr =  __ AddP(no_base, tls, __ ConX(index_offset));
4009 
4010   // Now some values
4011   // Use ctrl to avoid hoisting these values past a safepoint, which could
4012   // potentially reset these fields in the JavaThread.
4013   Node* index  = __ load(__ ctrl(), index_adr, TypeX_X, TypeX_X->basic_type(), Compile::AliasIdxRaw);
4014   Node* buffer = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
4015 
4016   // Convert the store obj pointer to an int prior to doing math on it
4017   // Must use ctrl to prevent "integerized oop" existing across safepoint
4018   Node* cast =  __ CastPX(__ ctrl(), adr);
4019 
4020   // Divide pointer by card size
4021   Node* card_offset = __ URShiftX( cast, __ ConI(CardTableModRefBS::card_shift) );
4022 
4023   // Combine card table base and card offset
4024   Node* card_adr = __ AddP(no_base, byte_map_base_node(), card_offset );
4025 
4026   // If we know the value being stored does it cross regions?
4027 
4028   if (val != NULL) {
4029     // Does the store cause us to cross regions?
4030 
4031     // Should be able to do an unsigned compare of region_size instead of
4032     // and extra shift. Do we have an unsigned compare??
4033     // Node* region_size = __ ConI(1 << HeapRegion::LogOfHRGrainBytes);
4034     Node* xor_res =  __ URShiftX ( __ XorX( cast,  __ CastPX(__ ctrl(), val)), __ ConI(HeapRegion::LogOfHRGrainBytes));
4035 
4036     // if (xor_res == 0) same region so skip
4037     __ if_then(xor_res, BoolTest::ne, zeroX); {
4038 
4039       // No barrier if we are storing a NULL
4040       __ if_then(val, BoolTest::ne, null(), unlikely); {
4041 
4042         // Ok must mark the card if not already dirty
4043 
4044         // load the original value of the card
4045         Node* card_val = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
4046 
4047         __ if_then(card_val, BoolTest::ne, young_card); {
4048           sync_kit(ideal);
4049           // Use Op_MemBarVolatile to achieve the effect of a StoreLoad barrier.
4050           insert_mem_bar(Op_MemBarVolatile, oop_store);
4051           __ sync_kit(this);
4052 
4053           Node* card_val_reload = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
4054           __ if_then(card_val_reload, BoolTest::ne, dirty_card); {
4055             g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
4056           } __ end_if();
4057         } __ end_if();
4058       } __ end_if();
4059     } __ end_if();
4060   } else {
4061     // Object.clone() instrinsic uses this path.
4062     g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
4063   }
4064 
4065   // Final sync IdealKit and GraphKit.
4066   final_sync(ideal);
4067 }
4068 #undef __
4069 
4070 
4071 
4072 Node* GraphKit::load_String_offset(Node* ctrl, Node* str) {
4073   if (java_lang_String::has_offset_field()) {
4074     int offset_offset = java_lang_String::offset_offset_in_bytes();
4075     const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4076                                                        false, NULL, 0);
4077     const TypePtr* offset_field_type = string_type->add_offset(offset_offset);
4078     int offset_field_idx = C->get_alias_index(offset_field_type);
4079     return make_load(ctrl,
4080                      basic_plus_adr(str, str, offset_offset),
4081                      TypeInt::INT, T_INT, offset_field_idx, MemNode::unordered);
4082   } else {
4083     return intcon(0);
4084   }
4085 }
4086 
4087 Node* GraphKit::load_String_length(Node* ctrl, Node* str) {
4088   if (java_lang_String::has_count_field()) {
4089     int count_offset = java_lang_String::count_offset_in_bytes();
4090     const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4091                                                        false, NULL, 0);
4092     const TypePtr* count_field_type = string_type->add_offset(count_offset);
4093     int count_field_idx = C->get_alias_index(count_field_type);
4094     return make_load(ctrl,
4095                      basic_plus_adr(str, str, count_offset),
4096                      TypeInt::INT, T_INT, count_field_idx, MemNode::unordered);
4097   } else {
4098     return load_array_length(load_String_value(ctrl, str));
4099   }
4100 }
4101 
4102 Node* GraphKit::load_String_value(Node* ctrl, Node* str) {
4103   int value_offset = java_lang_String::value_offset_in_bytes();
4104   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4105                                                      false, NULL, 0);
4106   const TypePtr* value_field_type = string_type->add_offset(value_offset);
4107   const TypeAryPtr*  value_type = TypeAryPtr::make(TypePtr::NotNull,
4108                                                    TypeAry::make(TypeInt::CHAR,TypeInt::POS),
4109                                                    ciTypeArrayKlass::make(T_CHAR), true, 0);
4110   int value_field_idx = C->get_alias_index(value_field_type);
4111   Node* load = make_load(ctrl, basic_plus_adr(str, str, value_offset),
4112                          value_type, T_OBJECT, value_field_idx, MemNode::unordered);
4113   // String.value field is known to be @Stable.
4114   if (UseImplicitStableValues) {
4115     load = cast_array_to_stable(load, value_type);
4116   }
4117   return load;
4118 }
4119 
4120 void GraphKit::store_String_offset(Node* ctrl, Node* str, Node* value) {
4121   int offset_offset = java_lang_String::offset_offset_in_bytes();
4122   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4123                                                      false, NULL, 0);
4124   const TypePtr* offset_field_type = string_type->add_offset(offset_offset);
4125   int offset_field_idx = C->get_alias_index(offset_field_type);
4126   store_to_memory(ctrl, basic_plus_adr(str, offset_offset),
4127                   value, T_INT, offset_field_idx, MemNode::unordered);
4128 }
4129 
4130 void GraphKit::store_String_value(Node* ctrl, Node* str, Node* value) {
4131   int value_offset = java_lang_String::value_offset_in_bytes();
4132   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4133                                                      false, NULL, 0);
4134   const TypePtr* value_field_type = string_type->add_offset(value_offset);
4135 
4136   store_oop_to_object(ctrl, str,  basic_plus_adr(str, value_offset), value_field_type,
4137       value, TypeAryPtr::CHARS, T_OBJECT, MemNode::unordered);
4138 }
4139 
4140 void GraphKit::store_String_length(Node* ctrl, Node* str, Node* value) {
4141   int count_offset = java_lang_String::count_offset_in_bytes();
4142   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4143                                                      false, NULL, 0);
4144   const TypePtr* count_field_type = string_type->add_offset(count_offset);
4145   int count_field_idx = C->get_alias_index(count_field_type);
4146   store_to_memory(ctrl, basic_plus_adr(str, count_offset),
4147                   value, T_INT, count_field_idx, MemNode::unordered);
4148 }
4149 
4150 Node* GraphKit::cast_array_to_stable(Node* ary, const TypeAryPtr* ary_type) {
4151   // Reify the property as a CastPP node in Ideal graph to comply with monotonicity
4152   // assumption of CCP analysis.
4153   return _gvn.transform(new(C) CastPPNode(ary, ary_type->cast_to_stable(true)));
4154 }