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