1 /*
   2  * Copyright 2005-2007 Sun Microsystems, Inc.  All Rights Reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  20  * CA 95054 USA or visit www.sun.com if you need additional information or
  21  * have any questions.
  22  *
  23  */
  24 
  25 #include "incls/_precompiled.incl"
  26 #include "incls/_macro.cpp.incl"
  27 
  28 
  29 //
  30 // Replace any references to "oldref" in inputs to "use" with "newref".
  31 // Returns the number of replacements made.
  32 //
  33 int PhaseMacroExpand::replace_input(Node *use, Node *oldref, Node *newref) {
  34   int nreplacements = 0;
  35   uint req = use->req();
  36   for (uint j = 0; j < use->len(); j++) {
  37     Node *uin = use->in(j);
  38     if (uin == oldref) {
  39       if (j < req)
  40         use->set_req(j, newref);
  41       else
  42         use->set_prec(j, newref);
  43       nreplacements++;
  44     } else if (j >= req && uin == NULL) {
  45       break;
  46     }
  47   }
  48   return nreplacements;
  49 }
  50 
  51 void PhaseMacroExpand::copy_call_debug_info(CallNode *oldcall, CallNode * newcall) {
  52   // Copy debug information and adjust JVMState information
  53   uint old_dbg_start = oldcall->tf()->domain()->cnt();
  54   uint new_dbg_start = newcall->tf()->domain()->cnt();
  55   int jvms_adj  = new_dbg_start - old_dbg_start;
  56   assert (new_dbg_start == newcall->req(), "argument count mismatch");
  57 
  58   Dict* sosn_map = new Dict(cmpkey,hashkey);
  59   for (uint i = old_dbg_start; i < oldcall->req(); i++) {
  60     Node* old_in = oldcall->in(i);
  61     // Clone old SafePointScalarObjectNodes, adjusting their field contents.
  62     if (old_in->is_SafePointScalarObject()) {
  63       SafePointScalarObjectNode* old_sosn = old_in->as_SafePointScalarObject();
  64       uint old_unique = C->unique();
  65       Node* new_in = old_sosn->clone(jvms_adj, sosn_map);
  66       if (old_unique != C->unique()) {
  67         new_in = transform_later(new_in); // Register new node.
  68       }
  69       old_in = new_in;
  70     }
  71     newcall->add_req(old_in);
  72   }
  73 
  74   newcall->set_jvms(oldcall->jvms());
  75   for (JVMState *jvms = newcall->jvms(); jvms != NULL; jvms = jvms->caller()) {
  76     jvms->set_map(newcall);
  77     jvms->set_locoff(jvms->locoff()+jvms_adj);
  78     jvms->set_stkoff(jvms->stkoff()+jvms_adj);
  79     jvms->set_monoff(jvms->monoff()+jvms_adj);
  80     jvms->set_scloff(jvms->scloff()+jvms_adj);
  81     jvms->set_endoff(jvms->endoff()+jvms_adj);
  82   }
  83 }
  84 
  85 Node* PhaseMacroExpand::opt_iff(Node* region, Node* iff) {
  86   IfNode *opt_iff = transform_later(iff)->as_If();
  87 
  88   // Fast path taken; set region slot 2
  89   Node *fast_taken = transform_later( new (C, 1) IfFalseNode(opt_iff) );
  90   region->init_req(2,fast_taken); // Capture fast-control
  91 
  92   // Fast path not-taken, i.e. slow path
  93   Node *slow_taken = transform_later( new (C, 1) IfTrueNode(opt_iff) );
  94   return slow_taken;
  95 }
  96 
  97 //--------------------copy_predefined_input_for_runtime_call--------------------
  98 void PhaseMacroExpand::copy_predefined_input_for_runtime_call(Node * ctrl, CallNode* oldcall, CallNode* call) {
  99   // Set fixed predefined input arguments
 100   call->init_req( TypeFunc::Control, ctrl );
 101   call->init_req( TypeFunc::I_O    , oldcall->in( TypeFunc::I_O) );
 102   call->init_req( TypeFunc::Memory , oldcall->in( TypeFunc::Memory ) ); // ?????
 103   call->init_req( TypeFunc::ReturnAdr, oldcall->in( TypeFunc::ReturnAdr ) );
 104   call->init_req( TypeFunc::FramePtr, oldcall->in( TypeFunc::FramePtr ) );
 105 }
 106 
 107 //------------------------------make_slow_call---------------------------------
 108 CallNode* PhaseMacroExpand::make_slow_call(CallNode *oldcall, const TypeFunc* slow_call_type, address slow_call, const char* leaf_name, Node* slow_path, Node* parm0, Node* parm1) {
 109 
 110   // Slow-path call
 111   int size = slow_call_type->domain()->cnt();
 112  CallNode *call = leaf_name
 113    ? (CallNode*)new (C, size) CallLeafNode      ( slow_call_type, slow_call, leaf_name, TypeRawPtr::BOTTOM )
 114    : (CallNode*)new (C, size) CallStaticJavaNode( slow_call_type, slow_call, OptoRuntime::stub_name(slow_call), oldcall->jvms()->bci(), TypeRawPtr::BOTTOM );
 115 
 116   // Slow path call has no side-effects, uses few values
 117   copy_predefined_input_for_runtime_call(slow_path, oldcall, call );
 118   if (parm0 != NULL)  call->init_req(TypeFunc::Parms+0, parm0);
 119   if (parm1 != NULL)  call->init_req(TypeFunc::Parms+1, parm1);
 120   copy_call_debug_info(oldcall, call);
 121   call->set_cnt(PROB_UNLIKELY_MAG(4));  // Same effect as RC_UNCOMMON.
 122   _igvn.hash_delete(oldcall);
 123   _igvn.subsume_node(oldcall, call);
 124   transform_later(call);
 125 
 126   return call;
 127 }
 128 
 129 void PhaseMacroExpand::extract_call_projections(CallNode *call) {
 130   _fallthroughproj = NULL;
 131   _fallthroughcatchproj = NULL;
 132   _ioproj_fallthrough = NULL;
 133   _ioproj_catchall = NULL;
 134   _catchallcatchproj = NULL;
 135   _memproj_fallthrough = NULL;
 136   _memproj_catchall = NULL;
 137   _resproj = NULL;
 138   for (DUIterator_Fast imax, i = call->fast_outs(imax); i < imax; i++) {
 139     ProjNode *pn = call->fast_out(i)->as_Proj();
 140     switch (pn->_con) {
 141       case TypeFunc::Control:
 142       {
 143         // For Control (fallthrough) and I_O (catch_all_index) we have CatchProj -> Catch -> Proj
 144         _fallthroughproj = pn;
 145         DUIterator_Fast jmax, j = pn->fast_outs(jmax);
 146         const Node *cn = pn->fast_out(j);
 147         if (cn->is_Catch()) {
 148           ProjNode *cpn = NULL;
 149           for (DUIterator_Fast kmax, k = cn->fast_outs(kmax); k < kmax; k++) {
 150             cpn = cn->fast_out(k)->as_Proj();
 151             assert(cpn->is_CatchProj(), "must be a CatchProjNode");
 152             if (cpn->_con == CatchProjNode::fall_through_index)
 153               _fallthroughcatchproj = cpn;
 154             else {
 155               assert(cpn->_con == CatchProjNode::catch_all_index, "must be correct index.");
 156               _catchallcatchproj = cpn;
 157             }
 158           }
 159         }
 160         break;
 161       }
 162       case TypeFunc::I_O:
 163         if (pn->_is_io_use)
 164           _ioproj_catchall = pn;
 165         else
 166           _ioproj_fallthrough = pn;
 167         break;
 168       case TypeFunc::Memory:
 169         if (pn->_is_io_use)
 170           _memproj_catchall = pn;
 171         else
 172           _memproj_fallthrough = pn;
 173         break;
 174       case TypeFunc::Parms:
 175         _resproj = pn;
 176         break;
 177       default:
 178         assert(false, "unexpected projection from allocation node.");
 179     }
 180   }
 181 
 182 }
 183 
 184 // Eliminate a card mark sequence.  p2x is a ConvP2XNode
 185 void PhaseMacroExpand::eliminate_card_mark(Node *p2x) {
 186   assert(p2x->Opcode() == Op_CastP2X, "ConvP2XNode required");
 187   Node *shift = p2x->unique_out();
 188   Node *addp = shift->unique_out();
 189   for (DUIterator_Last jmin, j = addp->last_outs(jmin); j >= jmin; --j) {
 190     Node *st = addp->last_out(j);
 191     assert(st->is_Store(), "store required");
 192     _igvn.replace_node(st, st->in(MemNode::Memory));
 193   }
 194 }
 195 
 196 // Search for a memory operation for the specified memory slice.
 197 static Node *scan_mem_chain(Node *mem, int alias_idx, int offset, Node *start_mem, Node *alloc) {
 198   Node *orig_mem = mem;
 199   Node *alloc_mem = alloc->in(TypeFunc::Memory);
 200   while (true) {
 201     if (mem == alloc_mem || mem == start_mem ) {
 202       return mem;  // hit one of our sentinals
 203     } else if (mem->is_MergeMem()) {
 204       mem = mem->as_MergeMem()->memory_at(alias_idx);
 205     } else if (mem->is_Proj() && mem->as_Proj()->_con == TypeFunc::Memory) {
 206       Node *in = mem->in(0);
 207       // we can safely skip over safepoints, calls, locks and membars because we
 208       // already know that the object is safe to eliminate.
 209       if (in->is_Initialize() && in->as_Initialize()->allocation() == alloc) {
 210         return in;
 211       } else if (in->is_Call() || in->is_MemBar()) {
 212         mem = in->in(TypeFunc::Memory);
 213       } else {
 214         assert(false, "unexpected projection");
 215       }
 216     } else if (mem->is_Store()) {
 217       const TypePtr* atype = mem->as_Store()->adr_type();
 218       int adr_idx = Compile::current()->get_alias_index(atype);
 219       if (adr_idx == alias_idx) {
 220         assert(atype->isa_oopptr(), "address type must be oopptr");
 221         int adr_offset = atype->offset();
 222         uint adr_iid = atype->is_oopptr()->instance_id();
 223         // Array elements references have the same alias_idx
 224         // but different offset and different instance_id.
 225         if (adr_offset == offset && adr_iid == alloc->_idx)
 226           return mem;
 227       } else {
 228         assert(adr_idx == Compile::AliasIdxRaw, "address must match or be raw");
 229       }
 230       mem = mem->in(MemNode::Memory);
 231     } else {
 232       return mem;
 233     }
 234     if (mem == orig_mem)
 235       return mem;
 236   }
 237 }
 238 
 239 //
 240 // Given a Memory Phi, compute a value Phi containing the values from stores
 241 // on the input paths.
 242 // Note: this function is recursive, its depth is limied by the "level" argument
 243 // Returns the computed Phi, or NULL if it cannot compute it.
 244 Node *PhaseMacroExpand::value_from_mem_phi(Node *mem, BasicType ft, const Type *phi_type, const TypeOopPtr *adr_t, Node *alloc, int level) {
 245 
 246   if (level <= 0) {
 247     return NULL;
 248   }
 249   int alias_idx = C->get_alias_index(adr_t);
 250   int offset = adr_t->offset();
 251   int instance_id = adr_t->instance_id();
 252 
 253   Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
 254   Node *alloc_mem = alloc->in(TypeFunc::Memory);
 255 
 256   uint length = mem->req();
 257   GrowableArray <Node *> values(length, length, NULL);
 258 
 259   for (uint j = 1; j < length; j++) {
 260     Node *in = mem->in(j);
 261     if (in == NULL || in->is_top()) {
 262       values.at_put(j, in);
 263     } else  {
 264       Node *val = scan_mem_chain(in, alias_idx, offset, start_mem, alloc);
 265       if (val == start_mem || val == alloc_mem) {
 266         // hit a sentinel, return appropriate 0 value
 267         values.at_put(j, _igvn.zerocon(ft));
 268         continue;
 269       }
 270       if (val->is_Initialize()) {
 271         val = val->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn);
 272       }
 273       if (val == NULL) {
 274         return NULL;  // can't find a value on this path
 275       }
 276       if (val == mem) {
 277         values.at_put(j, mem);
 278       } else if (val->is_Store()) {
 279         values.at_put(j, val->in(MemNode::ValueIn));
 280       } else if(val->is_Proj() && val->in(0) == alloc) {
 281         values.at_put(j, _igvn.zerocon(ft));
 282       } else if (val->is_Phi()) {
 283         // Check if an appropriate node already exists.
 284         Node* region = val->in(0);
 285         Node* old_phi = NULL;
 286         for (DUIterator_Fast kmax, k = region->fast_outs(kmax); k < kmax; k++) {
 287           Node* phi = region->fast_out(k);
 288           if (phi->is_Phi() && phi != val &&
 289               phi->as_Phi()->is_same_inst_field(phi_type, instance_id, alias_idx, offset)) {
 290             old_phi = phi;
 291             break;
 292           }
 293         }
 294         if (old_phi == NULL) {
 295           val = value_from_mem_phi(val, ft, phi_type, adr_t, alloc, level-1);
 296           if (val == NULL) {
 297             return NULL;
 298           }
 299           values.at_put(j, val);
 300         } else {
 301           values.at_put(j, old_phi);
 302         }
 303       } else {
 304         return NULL;  // unknown node  on this path
 305       }
 306     }
 307   }
 308   // create a new Phi for the value
 309   PhiNode *phi = new (C, length) PhiNode(mem->in(0), phi_type, NULL, instance_id, alias_idx, offset);
 310   for (uint j = 1; j < length; j++) {
 311     if (values.at(j) == mem) {
 312       phi->init_req(j, phi);
 313     } else {
 314       phi->init_req(j, values.at(j));
 315     }
 316   }
 317   transform_later(phi);
 318   return phi;
 319 }
 320 
 321 // Search the last value stored into the object's field.
 322 Node *PhaseMacroExpand::value_from_mem(Node *sfpt_mem, BasicType ft, const Type *ftype, const TypeOopPtr *adr_t, Node *alloc) {
 323   assert(adr_t->is_instance_field(), "instance required");
 324   uint instance_id = adr_t->instance_id();
 325   assert(instance_id == alloc->_idx, "wrong allocation");
 326 
 327   int alias_idx = C->get_alias_index(adr_t);
 328   int offset = adr_t->offset();
 329   Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
 330   Node *alloc_ctrl = alloc->in(TypeFunc::Control);
 331   Node *alloc_mem = alloc->in(TypeFunc::Memory);
 332   VectorSet visited(Thread::current()->resource_area());
 333 
 334 
 335   bool done = sfpt_mem == alloc_mem;
 336   Node *mem = sfpt_mem;
 337   while (!done) {
 338     if (visited.test_set(mem->_idx)) {
 339       return NULL;  // found a loop, give up
 340     }
 341     mem = scan_mem_chain(mem, alias_idx, offset, start_mem, alloc);
 342     if (mem == start_mem || mem == alloc_mem) {
 343       done = true;  // hit a sentinel, return appropriate 0 value
 344     } else if (mem->is_Initialize()) {
 345       mem = mem->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn);
 346       if (mem == NULL) {
 347         done = true; // Something go wrong.
 348       } else if (mem->is_Store()) {
 349         const TypePtr* atype = mem->as_Store()->adr_type();
 350         assert(C->get_alias_index(atype) == Compile::AliasIdxRaw, "store is correct memory slice");
 351         done = true;
 352       }
 353     } else if (mem->is_Store()) {
 354       const TypeOopPtr* atype = mem->as_Store()->adr_type()->isa_oopptr();
 355       assert(atype != NULL, "address type must be oopptr");
 356       assert(C->get_alias_index(atype) == alias_idx &&
 357              atype->is_instance_field() && atype->offset() == offset &&
 358              atype->instance_id() == instance_id, "store is correct memory slice");
 359       done = true;
 360     } else if (mem->is_Phi()) {
 361       // try to find a phi's unique input
 362       Node *unique_input = NULL;
 363       Node *top = C->top();
 364       for (uint i = 1; i < mem->req(); i++) {
 365         Node *n = scan_mem_chain(mem->in(i), alias_idx, offset, start_mem, alloc);
 366         if (n == NULL || n == top || n == mem) {
 367           continue;
 368         } else if (unique_input == NULL) {
 369           unique_input = n;
 370         } else if (unique_input != n) {
 371           unique_input = top;
 372           break;
 373         }
 374       }
 375       if (unique_input != NULL && unique_input != top) {
 376         mem = unique_input;
 377       } else {
 378         done = true;
 379       }
 380     } else {
 381       assert(false, "unexpected node");
 382     }
 383   }
 384   if (mem != NULL) {
 385     if (mem == start_mem || mem == alloc_mem) {
 386       // hit a sentinel, return appropriate 0 value
 387       return _igvn.zerocon(ft);
 388     } else if (mem->is_Store()) {
 389       return mem->in(MemNode::ValueIn);
 390     } else if (mem->is_Phi()) {
 391       // attempt to produce a Phi reflecting the values on the input paths of the Phi
 392       Node * phi = value_from_mem_phi(mem, ft, ftype, adr_t, alloc, 8);
 393       if (phi != NULL) {
 394         return phi;
 395       }
 396     }
 397   }
 398   // Something go wrong.
 399   return NULL;
 400 }
 401 
 402 // Check the possibility of scalar replacement.
 403 bool PhaseMacroExpand::can_eliminate_allocation(AllocateNode *alloc, GrowableArray <SafePointNode *>& safepoints) {
 404   //  Scan the uses of the allocation to check for anything that would
 405   //  prevent us from eliminating it.
 406   NOT_PRODUCT( const char* fail_eliminate = NULL; )
 407   DEBUG_ONLY( Node* disq_node = NULL; )
 408   bool  can_eliminate = true;
 409 
 410   Node* res = alloc->result_cast();
 411   const TypeOopPtr* res_type = NULL;
 412   if (res == NULL) {
 413     // All users were eliminated.
 414   } else if (!res->is_CheckCastPP()) {
 415     alloc->_is_scalar_replaceable = false;  // don't try again
 416     NOT_PRODUCT(fail_eliminate = "Allocation does not have unique CheckCastPP";)
 417     can_eliminate = false;
 418   } else {
 419     res_type = _igvn.type(res)->isa_oopptr();
 420     if (res_type == NULL) {
 421       NOT_PRODUCT(fail_eliminate = "Neither instance or array allocation";)
 422       can_eliminate = false;
 423     } else if (res_type->isa_aryptr()) {
 424       int length = alloc->in(AllocateNode::ALength)->find_int_con(-1);
 425       if (length < 0) {
 426         NOT_PRODUCT(fail_eliminate = "Array's size is not constant";)
 427         can_eliminate = false;
 428       }
 429     }
 430   }
 431 
 432   if (can_eliminate && res != NULL) {
 433     for (DUIterator_Fast jmax, j = res->fast_outs(jmax);
 434                                j < jmax && can_eliminate; j++) {
 435       Node* use = res->fast_out(j);
 436 
 437       if (use->is_AddP()) {
 438         const TypePtr* addp_type = _igvn.type(use)->is_ptr();
 439         int offset = addp_type->offset();
 440 
 441         if (offset == Type::OffsetTop || offset == Type::OffsetBot) {
 442           NOT_PRODUCT(fail_eliminate = "Undefined field referrence";)
 443           can_eliminate = false;
 444           break;
 445         }
 446         for (DUIterator_Fast kmax, k = use->fast_outs(kmax);
 447                                    k < kmax && can_eliminate; k++) {
 448           Node* n = use->fast_out(k);
 449           if (!n->is_Store() && n->Opcode() != Op_CastP2X) {
 450             DEBUG_ONLY(disq_node = n;)
 451             if (n->is_Load()) {
 452               NOT_PRODUCT(fail_eliminate = "Field load";)
 453             } else {
 454               NOT_PRODUCT(fail_eliminate = "Not store field referrence";)
 455             }
 456             can_eliminate = false;
 457           }
 458         }
 459       } else if (use->is_SafePoint()) {
 460         SafePointNode* sfpt = use->as_SafePoint();
 461         if (sfpt->is_Call() && sfpt->as_Call()->has_non_debug_use(res)) {
 462           // Object is passed as argument.
 463           DEBUG_ONLY(disq_node = use;)
 464           NOT_PRODUCT(fail_eliminate = "Object is passed as argument";)
 465           can_eliminate = false;
 466         }
 467         Node* sfptMem = sfpt->memory();
 468         if (sfptMem == NULL || sfptMem->is_top()) {
 469           DEBUG_ONLY(disq_node = use;)
 470           NOT_PRODUCT(fail_eliminate = "NULL or TOP memory";)
 471           can_eliminate = false;
 472         } else {
 473           safepoints.append_if_missing(sfpt);
 474         }
 475       } else if (use->Opcode() != Op_CastP2X) { // CastP2X is used by card mark
 476         if (use->is_Phi()) {
 477           if (use->outcnt() == 1 && use->unique_out()->Opcode() == Op_Return) {
 478             NOT_PRODUCT(fail_eliminate = "Object is return value";)
 479           } else {
 480             NOT_PRODUCT(fail_eliminate = "Object is referenced by Phi";)
 481           }
 482           DEBUG_ONLY(disq_node = use;)
 483         } else {
 484           if (use->Opcode() == Op_Return) {
 485             NOT_PRODUCT(fail_eliminate = "Object is return value";)
 486           }else {
 487             NOT_PRODUCT(fail_eliminate = "Object is referenced by node";)
 488           }
 489           DEBUG_ONLY(disq_node = use;)
 490         }
 491         can_eliminate = false;
 492       }
 493     }
 494   }
 495 
 496 #ifndef PRODUCT
 497   if (PrintEliminateAllocations) {
 498     if (can_eliminate) {
 499       tty->print("Scalar ");
 500       if (res == NULL)
 501         alloc->dump();
 502       else
 503         res->dump();
 504     } else {
 505       tty->print("NotScalar (%s)", fail_eliminate);
 506       if (res == NULL)
 507         alloc->dump();
 508       else
 509         res->dump();
 510 #ifdef ASSERT
 511       if (disq_node != NULL) {
 512           tty->print("  >>>> ");
 513           disq_node->dump();
 514       }
 515 #endif /*ASSERT*/
 516     }
 517   }
 518 #endif
 519   return can_eliminate;
 520 }
 521 
 522 // Do scalar replacement.
 523 bool PhaseMacroExpand::scalar_replacement(AllocateNode *alloc, GrowableArray <SafePointNode *>& safepoints) {
 524   GrowableArray <SafePointNode *> safepoints_done;
 525 
 526   ciKlass* klass = NULL;
 527   ciInstanceKlass* iklass = NULL;
 528   int nfields = 0;
 529   int array_base;
 530   int element_size;
 531   BasicType basic_elem_type;
 532   ciType* elem_type;
 533 
 534   Node* res = alloc->result_cast();
 535   const TypeOopPtr* res_type = NULL;
 536   if (res != NULL) { // Could be NULL when there are no users
 537     res_type = _igvn.type(res)->isa_oopptr();
 538   }
 539 
 540   if (res != NULL) {
 541     klass = res_type->klass();
 542     if (res_type->isa_instptr()) {
 543       // find the fields of the class which will be needed for safepoint debug information
 544       assert(klass->is_instance_klass(), "must be an instance klass.");
 545       iklass = klass->as_instance_klass();
 546       nfields = iklass->nof_nonstatic_fields();
 547     } else {
 548       // find the array's elements which will be needed for safepoint debug information
 549       nfields = alloc->in(AllocateNode::ALength)->find_int_con(-1);
 550       assert(klass->is_array_klass() && nfields >= 0, "must be an array klass.");
 551       elem_type = klass->as_array_klass()->element_type();
 552       basic_elem_type = elem_type->basic_type();
 553       array_base = arrayOopDesc::base_offset_in_bytes(basic_elem_type);
 554       element_size = type2aelembytes(basic_elem_type);
 555     }
 556   }
 557   //
 558   // Process the safepoint uses
 559   //
 560   while (safepoints.length() > 0) {
 561     SafePointNode* sfpt = safepoints.pop();
 562     Node* mem = sfpt->memory();
 563     uint first_ind = sfpt->req();
 564     SafePointScalarObjectNode* sobj = new (C, 1) SafePointScalarObjectNode(res_type,
 565 #ifdef ASSERT
 566                                                  alloc,
 567 #endif
 568                                                  first_ind, nfields);
 569     sobj->init_req(0, sfpt->in(TypeFunc::Control));
 570     transform_later(sobj);
 571 
 572     // Scan object's fields adding an input to the safepoint for each field.
 573     for (int j = 0; j < nfields; j++) {
 574       int offset;
 575       ciField* field = NULL;
 576       if (iklass != NULL) {
 577         field = iklass->nonstatic_field_at(j);
 578         offset = field->offset();
 579         elem_type = field->type();
 580         basic_elem_type = field->layout_type();
 581       } else {
 582         offset = array_base + j * element_size;
 583       }
 584 
 585       const Type *field_type;
 586       // The next code is taken from Parse::do_get_xxx().
 587       if (basic_elem_type == T_OBJECT || basic_elem_type == T_ARRAY) {
 588         if (!elem_type->is_loaded()) {
 589           field_type = TypeInstPtr::BOTTOM;
 590         } else if (field != NULL && field->is_constant()) {
 591           // This can happen if the constant oop is non-perm.
 592           ciObject* con = field->constant_value().as_object();
 593           // Do not "join" in the previous type; it doesn't add value,
 594           // and may yield a vacuous result if the field is of interface type.
 595           field_type = TypeOopPtr::make_from_constant(con)->isa_oopptr();
 596           assert(field_type != NULL, "field singleton type must be consistent");
 597         } else {
 598           field_type = TypeOopPtr::make_from_klass(elem_type->as_klass());
 599         }
 600         if (UseCompressedOops) {
 601           field_type = field_type->make_narrowoop();
 602           basic_elem_type = T_NARROWOOP;
 603         }
 604       } else {
 605         field_type = Type::get_const_basic_type(basic_elem_type);
 606       }
 607 
 608       const TypeOopPtr *field_addr_type = res_type->add_offset(offset)->isa_oopptr();
 609 
 610       Node *field_val = value_from_mem(mem, basic_elem_type, field_type, field_addr_type, alloc);
 611       if (field_val == NULL) {
 612         // we weren't able to find a value for this field,
 613         // give up on eliminating this allocation
 614         alloc->_is_scalar_replaceable = false;  // don't try again
 615         // remove any extra entries we added to the safepoint
 616         uint last = sfpt->req() - 1;
 617         for (int k = 0;  k < j; k++) {
 618           sfpt->del_req(last--);
 619         }
 620         // rollback processed safepoints
 621         while (safepoints_done.length() > 0) {
 622           SafePointNode* sfpt_done = safepoints_done.pop();
 623           // remove any extra entries we added to the safepoint
 624           last = sfpt_done->req() - 1;
 625           for (int k = 0;  k < nfields; k++) {
 626             sfpt_done->del_req(last--);
 627           }
 628           JVMState *jvms = sfpt_done->jvms();
 629           jvms->set_endoff(sfpt_done->req());
 630           // Now make a pass over the debug information replacing any references
 631           // to SafePointScalarObjectNode with the allocated object.
 632           int start = jvms->debug_start();
 633           int end   = jvms->debug_end();
 634           for (int i = start; i < end; i++) {
 635             if (sfpt_done->in(i)->is_SafePointScalarObject()) {
 636               SafePointScalarObjectNode* scobj = sfpt_done->in(i)->as_SafePointScalarObject();
 637               if (scobj->first_index() == sfpt_done->req() &&
 638                   scobj->n_fields() == (uint)nfields) {
 639                 assert(scobj->alloc() == alloc, "sanity");
 640                 sfpt_done->set_req(i, res);
 641               }
 642             }
 643           }
 644         }
 645 #ifndef PRODUCT
 646         if (PrintEliminateAllocations) {
 647           if (field != NULL) {
 648             tty->print("=== At SafePoint node %d can't find value of Field: ",
 649                        sfpt->_idx);
 650             field->print();
 651             int field_idx = C->get_alias_index(field_addr_type);
 652             tty->print(" (alias_idx=%d)", field_idx);
 653           } else { // Array's element
 654             tty->print("=== At SafePoint node %d can't find value of array element [%d]",
 655                        sfpt->_idx, j);
 656           }
 657           tty->print(", which prevents elimination of: ");
 658           if (res == NULL)
 659             alloc->dump();
 660           else
 661             res->dump();
 662         }
 663 #endif
 664         return false;
 665       }
 666       if (UseCompressedOops && field_type->isa_narrowoop()) {
 667         // Enable "DecodeN(EncodeP(Allocate)) --> Allocate" transformation
 668         // to be able scalar replace the allocation.
 669         if (field_val->is_EncodeP()) {
 670           field_val = field_val->in(1);
 671         } else {
 672           field_val = transform_later(new (C, 2) DecodeNNode(field_val, field_val->bottom_type()->make_ptr()));
 673         }
 674       }
 675       sfpt->add_req(field_val);
 676     }
 677     JVMState *jvms = sfpt->jvms();
 678     jvms->set_endoff(sfpt->req());
 679     // Now make a pass over the debug information replacing any references
 680     // to the allocated object with "sobj"
 681     int start = jvms->debug_start();
 682     int end   = jvms->debug_end();
 683     for (int i = start; i < end; i++) {
 684       if (sfpt->in(i) == res) {
 685         sfpt->set_req(i, sobj);
 686       }
 687     }
 688     safepoints_done.append_if_missing(sfpt); // keep it for rollback
 689   }
 690   return true;
 691 }
 692 
 693 // Process users of eliminated allocation.
 694 void PhaseMacroExpand::process_users_of_allocation(AllocateNode *alloc) {
 695   Node* res = alloc->result_cast();
 696   if (res != NULL) {
 697     for (DUIterator_Last jmin, j = res->last_outs(jmin); j >= jmin; ) {
 698       Node *use = res->last_out(j);
 699       uint oc1 = res->outcnt();
 700 
 701       if (use->is_AddP()) {
 702         for (DUIterator_Last kmin, k = use->last_outs(kmin); k >= kmin; ) {
 703           Node *n = use->last_out(k);
 704           uint oc2 = use->outcnt();
 705           if (n->is_Store()) {
 706             _igvn.replace_node(n, n->in(MemNode::Memory));
 707           } else {
 708             assert( n->Opcode() == Op_CastP2X, "CastP2X required");
 709             eliminate_card_mark(n);
 710           }
 711           k -= (oc2 - use->outcnt());
 712         }
 713       } else {
 714         assert( !use->is_SafePoint(), "safepoint uses must have been already elimiated");
 715         assert( use->Opcode() == Op_CastP2X, "CastP2X required");
 716         eliminate_card_mark(use);
 717       }
 718       j -= (oc1 - res->outcnt());
 719     }
 720     assert(res->outcnt() == 0, "all uses of allocated objects must be deleted");
 721     _igvn.remove_dead_node(res);
 722   }
 723 
 724   //
 725   // Process other users of allocation's projections
 726   //
 727   if (_resproj != NULL && _resproj->outcnt() != 0) {
 728     for (DUIterator_Last jmin, j = _resproj->last_outs(jmin); j >= jmin; ) {
 729       Node *use = _resproj->last_out(j);
 730       uint oc1 = _resproj->outcnt();
 731       if (use->is_Initialize()) {
 732         // Eliminate Initialize node.
 733         InitializeNode *init = use->as_Initialize();
 734         assert(init->outcnt() <= 2, "only a control and memory projection expected");
 735         Node *ctrl_proj = init->proj_out(TypeFunc::Control);
 736         if (ctrl_proj != NULL) {
 737            assert(init->in(TypeFunc::Control) == _fallthroughcatchproj, "allocation control projection");
 738           _igvn.replace_node(ctrl_proj, _fallthroughcatchproj);
 739         }
 740         Node *mem_proj = init->proj_out(TypeFunc::Memory);
 741         if (mem_proj != NULL) {
 742           Node *mem = init->in(TypeFunc::Memory);
 743 #ifdef ASSERT
 744           if (mem->is_MergeMem()) {
 745             assert(mem->in(TypeFunc::Memory) == _memproj_fallthrough, "allocation memory projection");
 746           } else {
 747             assert(mem == _memproj_fallthrough, "allocation memory projection");
 748           }
 749 #endif
 750           _igvn.replace_node(mem_proj, mem);
 751         }
 752       } else if (use->is_AddP()) {
 753         // raw memory addresses used only by the initialization
 754         _igvn.hash_delete(use);
 755         _igvn.subsume_node(use, C->top());
 756       } else  {
 757         assert(false, "only Initialize or AddP expected");
 758       }
 759       j -= (oc1 - _resproj->outcnt());
 760     }
 761   }
 762   if (_fallthroughcatchproj != NULL) {
 763     _igvn.replace_node(_fallthroughcatchproj, alloc->in(TypeFunc::Control));
 764   }
 765   if (_memproj_fallthrough != NULL) {
 766     _igvn.replace_node(_memproj_fallthrough, alloc->in(TypeFunc::Memory));
 767   }
 768   if (_memproj_catchall != NULL) {
 769     _igvn.replace_node(_memproj_catchall, C->top());
 770   }
 771   if (_ioproj_fallthrough != NULL) {
 772     _igvn.replace_node(_ioproj_fallthrough, alloc->in(TypeFunc::I_O));
 773   }
 774   if (_ioproj_catchall != NULL) {
 775     _igvn.replace_node(_ioproj_catchall, C->top());
 776   }
 777   if (_catchallcatchproj != NULL) {
 778     _igvn.replace_node(_catchallcatchproj, C->top());
 779   }
 780 }
 781 
 782 bool PhaseMacroExpand::eliminate_allocate_node(AllocateNode *alloc) {
 783 
 784   if (!EliminateAllocations || !alloc->_is_scalar_replaceable) {
 785     return false;
 786   }
 787 
 788   extract_call_projections(alloc);
 789 
 790   GrowableArray <SafePointNode *> safepoints;
 791   if (!can_eliminate_allocation(alloc, safepoints)) {
 792     return false;
 793   }
 794 
 795   if (!scalar_replacement(alloc, safepoints)) {
 796     return false;
 797   }
 798 
 799   process_users_of_allocation(alloc);
 800 
 801 #ifndef PRODUCT
 802 if (PrintEliminateAllocations) {
 803   if (alloc->is_AllocateArray())
 804     tty->print_cr("++++ Eliminated: %d AllocateArray", alloc->_idx);
 805   else
 806     tty->print_cr("++++ Eliminated: %d Allocate", alloc->_idx);
 807 }
 808 #endif
 809 
 810   return true;
 811 }
 812 
 813 
 814 //---------------------------set_eden_pointers-------------------------
 815 void PhaseMacroExpand::set_eden_pointers(Node* &eden_top_adr, Node* &eden_end_adr) {
 816   if (UseTLAB) {                // Private allocation: load from TLS
 817     Node* thread = transform_later(new (C, 1) ThreadLocalNode());
 818     int tlab_top_offset = in_bytes(JavaThread::tlab_top_offset());
 819     int tlab_end_offset = in_bytes(JavaThread::tlab_end_offset());
 820     eden_top_adr = basic_plus_adr(top()/*not oop*/, thread, tlab_top_offset);
 821     eden_end_adr = basic_plus_adr(top()/*not oop*/, thread, tlab_end_offset);
 822   } else {                      // Shared allocation: load from globals
 823     CollectedHeap* ch = Universe::heap();
 824     address top_adr = (address)ch->top_addr();
 825     address end_adr = (address)ch->end_addr();
 826     eden_top_adr = makecon(TypeRawPtr::make(top_adr));
 827     eden_end_adr = basic_plus_adr(eden_top_adr, end_adr - top_adr);
 828   }
 829 }
 830 
 831 
 832 Node* PhaseMacroExpand::make_load(Node* ctl, Node* mem, Node* base, int offset, const Type* value_type, BasicType bt) {
 833   Node* adr = basic_plus_adr(base, offset);
 834   const TypePtr* adr_type = TypeRawPtr::BOTTOM;
 835   Node* value = LoadNode::make(_igvn, ctl, mem, adr, adr_type, value_type, bt);
 836   transform_later(value);
 837   return value;
 838 }
 839 
 840 
 841 Node* PhaseMacroExpand::make_store(Node* ctl, Node* mem, Node* base, int offset, Node* value, BasicType bt) {
 842   Node* adr = basic_plus_adr(base, offset);
 843   mem = StoreNode::make(_igvn, ctl, mem, adr, NULL, value, bt);
 844   transform_later(mem);
 845   return mem;
 846 }
 847 
 848 //=============================================================================
 849 //
 850 //                              A L L O C A T I O N
 851 //
 852 // Allocation attempts to be fast in the case of frequent small objects.
 853 // It breaks down like this:
 854 //
 855 // 1) Size in doublewords is computed.  This is a constant for objects and
 856 // variable for most arrays.  Doubleword units are used to avoid size
 857 // overflow of huge doubleword arrays.  We need doublewords in the end for
 858 // rounding.
 859 //
 860 // 2) Size is checked for being 'too large'.  Too-large allocations will go
 861 // the slow path into the VM.  The slow path can throw any required
 862 // exceptions, and does all the special checks for very large arrays.  The
 863 // size test can constant-fold away for objects.  For objects with
 864 // finalizers it constant-folds the otherway: you always go slow with
 865 // finalizers.
 866 //
 867 // 3) If NOT using TLABs, this is the contended loop-back point.
 868 // Load-Locked the heap top.  If using TLABs normal-load the heap top.
 869 //
 870 // 4) Check that heap top + size*8 < max.  If we fail go the slow ` route.
 871 // NOTE: "top+size*8" cannot wrap the 4Gig line!  Here's why: for largish
 872 // "size*8" we always enter the VM, where "largish" is a constant picked small
 873 // enough that there's always space between the eden max and 4Gig (old space is
 874 // there so it's quite large) and large enough that the cost of entering the VM
 875 // is dwarfed by the cost to initialize the space.
 876 //
 877 // 5) If NOT using TLABs, Store-Conditional the adjusted heap top back
 878 // down.  If contended, repeat at step 3.  If using TLABs normal-store
 879 // adjusted heap top back down; there is no contention.
 880 //
 881 // 6) If !ZeroTLAB then Bulk-clear the object/array.  Fill in klass & mark
 882 // fields.
 883 //
 884 // 7) Merge with the slow-path; cast the raw memory pointer to the correct
 885 // oop flavor.
 886 //
 887 //=============================================================================
 888 // FastAllocateSizeLimit value is in DOUBLEWORDS.
 889 // Allocations bigger than this always go the slow route.
 890 // This value must be small enough that allocation attempts that need to
 891 // trigger exceptions go the slow route.  Also, it must be small enough so
 892 // that heap_top + size_in_bytes does not wrap around the 4Gig limit.
 893 //=============================================================================j//
 894 // %%% Here is an old comment from parseHelper.cpp; is it outdated?
 895 // The allocator will coalesce int->oop copies away.  See comment in
 896 // coalesce.cpp about how this works.  It depends critically on the exact
 897 // code shape produced here, so if you are changing this code shape
 898 // make sure the GC info for the heap-top is correct in and around the
 899 // slow-path call.
 900 //
 901 
 902 void PhaseMacroExpand::expand_allocate_common(
 903             AllocateNode* alloc, // allocation node to be expanded
 904             Node* length,  // array length for an array allocation
 905             const TypeFunc* slow_call_type, // Type of slow call
 906             address slow_call_address  // Address of slow call
 907     )
 908 {
 909 
 910   Node* ctrl = alloc->in(TypeFunc::Control);
 911   Node* mem  = alloc->in(TypeFunc::Memory);
 912   Node* i_o  = alloc->in(TypeFunc::I_O);
 913   Node* size_in_bytes     = alloc->in(AllocateNode::AllocSize);
 914   Node* klass_node        = alloc->in(AllocateNode::KlassNode);
 915   Node* initial_slow_test = alloc->in(AllocateNode::InitialTest);
 916 
 917   // With escape analysis, the entire memory state was needed to be able to
 918   // eliminate the allocation.  Since the allocations cannot be eliminated,
 919   // optimize it to the raw slice.
 920   if (mem->is_MergeMem()) {
 921     mem = mem->as_MergeMem()->memory_at(Compile::AliasIdxRaw);
 922   }
 923 
 924   Node* eden_top_adr;
 925   Node* eden_end_adr;
 926   set_eden_pointers(eden_top_adr, eden_end_adr);
 927 
 928   uint raw_idx = C->get_alias_index(TypeRawPtr::BOTTOM);
 929   assert(ctrl != NULL, "must have control");
 930 
 931   // Load Eden::end.  Loop invariant and hoisted.
 932   //
 933   // Note: We set the control input on "eden_end" and "old_eden_top" when using
 934   //       a TLAB to work around a bug where these values were being moved across
 935   //       a safepoint.  These are not oops, so they cannot be include in the oop
 936   //       map, but the can be changed by a GC.   The proper way to fix this would
 937   //       be to set the raw memory state when generating a  SafepointNode.  However
 938   //       this will require extensive changes to the loop optimization in order to
 939   //       prevent a degradation of the optimization.
 940   //       See comment in memnode.hpp, around line 227 in class LoadPNode.
 941   Node* eden_end = make_load(ctrl, mem, eden_end_adr, 0, TypeRawPtr::BOTTOM, T_ADDRESS);
 942 
 943   // We need a Region and corresponding Phi's to merge the slow-path and fast-path results.
 944   // they will not be used if "always_slow" is set
 945   enum { slow_result_path = 1, fast_result_path = 2 };
 946   Node *result_region;
 947   Node *result_phi_rawmem;
 948   Node *result_phi_rawoop;
 949   Node *result_phi_i_o;
 950 
 951   // The initial slow comparison is a size check, the comparison
 952   // we want to do is a BoolTest::gt
 953   bool always_slow = false;
 954   int tv = _igvn.find_int_con(initial_slow_test, -1);
 955   if (tv >= 0) {
 956     always_slow = (tv == 1);
 957     initial_slow_test = NULL;
 958   } else {
 959     initial_slow_test = BoolNode::make_predicate(initial_slow_test, &_igvn);
 960   }
 961 
 962   if (DTraceAllocProbes) {
 963     // Force slow-path allocation
 964     always_slow = true;
 965     initial_slow_test = NULL;
 966   }
 967 
 968   enum { too_big_or_final_path = 1, need_gc_path = 2 };
 969   Node *slow_region = NULL;
 970   Node *toobig_false = ctrl;
 971 
 972   assert (initial_slow_test == NULL || !always_slow, "arguments must be consistent");
 973   // generate the initial test if necessary
 974   if (initial_slow_test != NULL ) {
 975     slow_region = new (C, 3) RegionNode(3);
 976 
 977     // Now make the initial failure test.  Usually a too-big test but
 978     // might be a TRUE for finalizers or a fancy class check for
 979     // newInstance0.
 980     IfNode *toobig_iff = new (C, 2) IfNode(ctrl, initial_slow_test, PROB_MIN, COUNT_UNKNOWN);
 981     transform_later(toobig_iff);
 982     // Plug the failing-too-big test into the slow-path region
 983     Node *toobig_true = new (C, 1) IfTrueNode( toobig_iff );
 984     transform_later(toobig_true);
 985     slow_region    ->init_req( too_big_or_final_path, toobig_true );
 986     toobig_false = new (C, 1) IfFalseNode( toobig_iff );
 987     transform_later(toobig_false);
 988   } else {         // No initial test, just fall into next case
 989     toobig_false = ctrl;
 990     debug_only(slow_region = NodeSentinel);
 991   }
 992 
 993   Node *slow_mem = mem;  // save the current memory state for slow path
 994   // generate the fast allocation code unless we know that the initial test will always go slow
 995   if (!always_slow) {
 996     // allocate the Region and Phi nodes for the result
 997     result_region = new (C, 3) RegionNode(3);
 998     result_phi_rawmem = new (C, 3) PhiNode( result_region, Type::MEMORY, TypeRawPtr::BOTTOM );
 999     result_phi_rawoop = new (C, 3) PhiNode( result_region, TypeRawPtr::BOTTOM );
1000     result_phi_i_o    = new (C, 3) PhiNode( result_region, Type::ABIO ); // I/O is used for Prefetch
1001 
1002     // We need a Region for the loop-back contended case.
1003     enum { fall_in_path = 1, contended_loopback_path = 2 };
1004     Node *contended_region;
1005     Node *contended_phi_rawmem;
1006     if( UseTLAB ) {
1007       contended_region = toobig_false;
1008       contended_phi_rawmem = mem;
1009     } else {
1010       contended_region = new (C, 3) RegionNode(3);
1011       contended_phi_rawmem = new (C, 3) PhiNode( contended_region, Type::MEMORY, TypeRawPtr::BOTTOM);
1012       // Now handle the passing-too-big test.  We fall into the contended
1013       // loop-back merge point.
1014       contended_region    ->init_req( fall_in_path, toobig_false );
1015       contended_phi_rawmem->init_req( fall_in_path, mem );
1016       transform_later(contended_region);
1017       transform_later(contended_phi_rawmem);
1018     }
1019 
1020     // Load(-locked) the heap top.
1021     // See note above concerning the control input when using a TLAB
1022     Node *old_eden_top = UseTLAB
1023       ? new (C, 3) LoadPNode     ( ctrl, contended_phi_rawmem, eden_top_adr, TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM )
1024       : new (C, 3) LoadPLockedNode( contended_region, contended_phi_rawmem, eden_top_adr );
1025 
1026     transform_later(old_eden_top);
1027     // Add to heap top to get a new heap top
1028     Node *new_eden_top = new (C, 4) AddPNode( top(), old_eden_top, size_in_bytes );
1029     transform_later(new_eden_top);
1030     // Check for needing a GC; compare against heap end
1031     Node *needgc_cmp = new (C, 3) CmpPNode( new_eden_top, eden_end );
1032     transform_later(needgc_cmp);
1033     Node *needgc_bol = new (C, 2) BoolNode( needgc_cmp, BoolTest::ge );
1034     transform_later(needgc_bol);
1035     IfNode *needgc_iff = new (C, 2) IfNode(contended_region, needgc_bol, PROB_UNLIKELY_MAG(4), COUNT_UNKNOWN );
1036     transform_later(needgc_iff);
1037 
1038     // Plug the failing-heap-space-need-gc test into the slow-path region
1039     Node *needgc_true = new (C, 1) IfTrueNode( needgc_iff );
1040     transform_later(needgc_true);
1041     if( initial_slow_test ) {
1042       slow_region    ->init_req( need_gc_path, needgc_true );
1043       // This completes all paths into the slow merge point
1044       transform_later(slow_region);
1045     } else {                      // No initial slow path needed!
1046       // Just fall from the need-GC path straight into the VM call.
1047       slow_region    = needgc_true;
1048     }
1049     // No need for a GC.  Setup for the Store-Conditional
1050     Node *needgc_false = new (C, 1) IfFalseNode( needgc_iff );
1051     transform_later(needgc_false);
1052 
1053     // Grab regular I/O before optional prefetch may change it.
1054     // Slow-path does no I/O so just set it to the original I/O.
1055     result_phi_i_o->init_req( slow_result_path, i_o );
1056 
1057     i_o = prefetch_allocation(i_o, needgc_false, contended_phi_rawmem,
1058                               old_eden_top, new_eden_top, length);
1059 
1060     // Store (-conditional) the modified eden top back down.
1061     // StorePConditional produces flags for a test PLUS a modified raw
1062     // memory state.
1063     Node *store_eden_top;
1064     Node *fast_oop_ctrl;
1065     if( UseTLAB ) {
1066       store_eden_top = new (C, 4) StorePNode( needgc_false, contended_phi_rawmem, eden_top_adr, TypeRawPtr::BOTTOM, new_eden_top );
1067       transform_later(store_eden_top);
1068       fast_oop_ctrl = needgc_false; // No contention, so this is the fast path
1069     } else {
1070       store_eden_top = new (C, 5) StorePConditionalNode( needgc_false, contended_phi_rawmem, eden_top_adr, new_eden_top, old_eden_top );
1071       transform_later(store_eden_top);
1072       Node *contention_check = new (C, 2) BoolNode( store_eden_top, BoolTest::ne );
1073       transform_later(contention_check);
1074       store_eden_top = new (C, 1) SCMemProjNode(store_eden_top);
1075       transform_later(store_eden_top);
1076 
1077       // If not using TLABs, check to see if there was contention.
1078       IfNode *contention_iff = new (C, 2) IfNode ( needgc_false, contention_check, PROB_MIN, COUNT_UNKNOWN );
1079       transform_later(contention_iff);
1080       Node *contention_true = new (C, 1) IfTrueNode( contention_iff );
1081       transform_later(contention_true);
1082       // If contention, loopback and try again.
1083       contended_region->init_req( contended_loopback_path, contention_true );
1084       contended_phi_rawmem->init_req( contended_loopback_path, store_eden_top );
1085 
1086       // Fast-path succeeded with no contention!
1087       Node *contention_false = new (C, 1) IfFalseNode( contention_iff );
1088       transform_later(contention_false);
1089       fast_oop_ctrl = contention_false;
1090     }
1091 
1092     // Rename successful fast-path variables to make meaning more obvious
1093     Node* fast_oop        = old_eden_top;
1094     Node* fast_oop_rawmem = store_eden_top;
1095     fast_oop_rawmem = initialize_object(alloc,
1096                                         fast_oop_ctrl, fast_oop_rawmem, fast_oop,
1097                                         klass_node, length, size_in_bytes);
1098 
1099     if (ExtendedDTraceProbes) {
1100       // Slow-path call
1101       int size = TypeFunc::Parms + 2;
1102       CallLeafNode *call = new (C, size) CallLeafNode(OptoRuntime::dtrace_object_alloc_Type(),
1103                                                       CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_object_alloc_base),
1104                                                       "dtrace_object_alloc",
1105                                                       TypeRawPtr::BOTTOM);
1106 
1107       // Get base of thread-local storage area
1108       Node* thread = new (C, 1) ThreadLocalNode();
1109       transform_later(thread);
1110 
1111       call->init_req(TypeFunc::Parms+0, thread);
1112       call->init_req(TypeFunc::Parms+1, fast_oop);
1113       call->init_req( TypeFunc::Control, fast_oop_ctrl );
1114       call->init_req( TypeFunc::I_O    , top() )        ;   // does no i/o
1115       call->init_req( TypeFunc::Memory , fast_oop_rawmem );
1116       call->init_req( TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr) );
1117       call->init_req( TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr) );
1118       transform_later(call);
1119       fast_oop_ctrl = new (C, 1) ProjNode(call,TypeFunc::Control);
1120       transform_later(fast_oop_ctrl);
1121       fast_oop_rawmem = new (C, 1) ProjNode(call,TypeFunc::Memory);
1122       transform_later(fast_oop_rawmem);
1123     }
1124 
1125     // Plug in the successful fast-path into the result merge point
1126     result_region    ->init_req( fast_result_path, fast_oop_ctrl );
1127     result_phi_rawoop->init_req( fast_result_path, fast_oop );
1128     result_phi_i_o   ->init_req( fast_result_path, i_o );
1129     result_phi_rawmem->init_req( fast_result_path, fast_oop_rawmem );
1130   } else {
1131     slow_region = ctrl;
1132   }
1133 
1134   // Generate slow-path call
1135   CallNode *call = new (C, slow_call_type->domain()->cnt())
1136     CallStaticJavaNode(slow_call_type, slow_call_address,
1137                        OptoRuntime::stub_name(slow_call_address),
1138                        alloc->jvms()->bci(),
1139                        TypePtr::BOTTOM);
1140   call->init_req( TypeFunc::Control, slow_region );
1141   call->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
1142   call->init_req( TypeFunc::Memory , slow_mem ); // may gc ptrs
1143   call->init_req( TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr) );
1144   call->init_req( TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr) );
1145 
1146   call->init_req(TypeFunc::Parms+0, klass_node);
1147   if (length != NULL) {
1148     call->init_req(TypeFunc::Parms+1, length);
1149   }
1150 
1151   // Copy debug information and adjust JVMState information, then replace
1152   // allocate node with the call
1153   copy_call_debug_info((CallNode *) alloc,  call);
1154   if (!always_slow) {
1155     call->set_cnt(PROB_UNLIKELY_MAG(4));  // Same effect as RC_UNCOMMON.
1156   }
1157   _igvn.hash_delete(alloc);
1158   _igvn.subsume_node(alloc, call);
1159   transform_later(call);
1160 
1161   // Identify the output projections from the allocate node and
1162   // adjust any references to them.
1163   // The control and io projections look like:
1164   //
1165   //        v---Proj(ctrl) <-----+   v---CatchProj(ctrl)
1166   //  Allocate                   Catch
1167   //        ^---Proj(io) <-------+   ^---CatchProj(io)
1168   //
1169   //  We are interested in the CatchProj nodes.
1170   //
1171   extract_call_projections(call);
1172 
1173   // An allocate node has separate memory projections for the uses on the control and i_o paths
1174   // Replace uses of the control memory projection with result_phi_rawmem (unless we are only generating a slow call)
1175   if (!always_slow && _memproj_fallthrough != NULL) {
1176     for (DUIterator_Fast imax, i = _memproj_fallthrough->fast_outs(imax); i < imax; i++) {
1177       Node *use = _memproj_fallthrough->fast_out(i);
1178       _igvn.hash_delete(use);
1179       imax -= replace_input(use, _memproj_fallthrough, result_phi_rawmem);
1180       _igvn._worklist.push(use);
1181       // back up iterator
1182       --i;
1183     }
1184   }
1185   // Now change uses of _memproj_catchall to use _memproj_fallthrough and delete _memproj_catchall so
1186   // we end up with a call that has only 1 memory projection
1187   if (_memproj_catchall != NULL ) {
1188     if (_memproj_fallthrough == NULL) {
1189       _memproj_fallthrough = new (C, 1) ProjNode(call, TypeFunc::Memory);
1190       transform_later(_memproj_fallthrough);
1191     }
1192     for (DUIterator_Fast imax, i = _memproj_catchall->fast_outs(imax); i < imax; i++) {
1193       Node *use = _memproj_catchall->fast_out(i);
1194       _igvn.hash_delete(use);
1195       imax -= replace_input(use, _memproj_catchall, _memproj_fallthrough);
1196       _igvn._worklist.push(use);
1197       // back up iterator
1198       --i;
1199     }
1200   }
1201 
1202   mem = result_phi_rawmem;
1203 
1204   // An allocate node has separate i_o projections for the uses on the control and i_o paths
1205   // Replace uses of the control i_o projection with result_phi_i_o (unless we are only generating a slow call)
1206   if (_ioproj_fallthrough == NULL) {
1207     _ioproj_fallthrough = new (C, 1) ProjNode(call, TypeFunc::I_O);
1208     transform_later(_ioproj_fallthrough);
1209   } else if (!always_slow) {
1210     for (DUIterator_Fast imax, i = _ioproj_fallthrough->fast_outs(imax); i < imax; i++) {
1211       Node *use = _ioproj_fallthrough->fast_out(i);
1212 
1213       _igvn.hash_delete(use);
1214       imax -= replace_input(use, _ioproj_fallthrough, result_phi_i_o);
1215       _igvn._worklist.push(use);
1216       // back up iterator
1217       --i;
1218     }
1219   }
1220   // Now change uses of _ioproj_catchall to use _ioproj_fallthrough and delete _ioproj_catchall so
1221   // we end up with a call that has only 1 control projection
1222   if (_ioproj_catchall != NULL ) {
1223     for (DUIterator_Fast imax, i = _ioproj_catchall->fast_outs(imax); i < imax; i++) {
1224       Node *use = _ioproj_catchall->fast_out(i);
1225       _igvn.hash_delete(use);
1226       imax -= replace_input(use, _ioproj_catchall, _ioproj_fallthrough);
1227       _igvn._worklist.push(use);
1228       // back up iterator
1229       --i;
1230     }
1231   }
1232 
1233   // if we generated only a slow call, we are done
1234   if (always_slow)
1235     return;
1236 
1237 
1238   if (_fallthroughcatchproj != NULL) {
1239     ctrl = _fallthroughcatchproj->clone();
1240     transform_later(ctrl);
1241     _igvn.hash_delete(_fallthroughcatchproj);
1242     _igvn.subsume_node(_fallthroughcatchproj, result_region);
1243   } else {
1244     ctrl = top();
1245   }
1246   Node *slow_result;
1247   if (_resproj == NULL) {
1248     // no uses of the allocation result
1249     slow_result = top();
1250   } else {
1251     slow_result = _resproj->clone();
1252     transform_later(slow_result);
1253     _igvn.hash_delete(_resproj);
1254     _igvn.subsume_node(_resproj, result_phi_rawoop);
1255   }
1256 
1257   // Plug slow-path into result merge point
1258   result_region    ->init_req( slow_result_path, ctrl );
1259   result_phi_rawoop->init_req( slow_result_path, slow_result);
1260   result_phi_rawmem->init_req( slow_result_path, _memproj_fallthrough );
1261   transform_later(result_region);
1262   transform_later(result_phi_rawoop);
1263   transform_later(result_phi_rawmem);
1264   transform_later(result_phi_i_o);
1265   // This completes all paths into the result merge point
1266 }
1267 
1268 
1269 // Helper for PhaseMacroExpand::expand_allocate_common.
1270 // Initializes the newly-allocated storage.
1271 Node*
1272 PhaseMacroExpand::initialize_object(AllocateNode* alloc,
1273                                     Node* control, Node* rawmem, Node* object,
1274                                     Node* klass_node, Node* length,
1275                                     Node* size_in_bytes) {
1276   InitializeNode* init = alloc->initialization();
1277   // Store the klass & mark bits
1278   Node* mark_node = NULL;
1279   // For now only enable fast locking for non-array types
1280   if (UseBiasedLocking && (length == NULL)) {
1281     mark_node = make_load(NULL, rawmem, klass_node, Klass::prototype_header_offset_in_bytes() + sizeof(oopDesc), TypeRawPtr::BOTTOM, T_ADDRESS);
1282   } else {
1283     mark_node = makecon(TypeRawPtr::make((address)markOopDesc::prototype()));
1284   }
1285   rawmem = make_store(control, rawmem, object, oopDesc::mark_offset_in_bytes(), mark_node, T_ADDRESS);
1286 
1287   rawmem = make_store(control, rawmem, object, oopDesc::klass_offset_in_bytes(), klass_node, T_OBJECT);
1288   int header_size = alloc->minimum_header_size();  // conservatively small
1289 
1290   // Array length
1291   if (length != NULL) {         // Arrays need length field
1292     rawmem = make_store(control, rawmem, object, arrayOopDesc::length_offset_in_bytes(), length, T_INT);
1293     // conservatively small header size:
1294     header_size = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1295     ciKlass* k = _igvn.type(klass_node)->is_klassptr()->klass();
1296     if (k->is_array_klass())    // we know the exact header size in most cases:
1297       header_size = Klass::layout_helper_header_size(k->layout_helper());
1298   }
1299 
1300   // Clear the object body, if necessary.
1301   if (init == NULL) {
1302     // The init has somehow disappeared; be cautious and clear everything.
1303     //
1304     // This can happen if a node is allocated but an uncommon trap occurs
1305     // immediately.  In this case, the Initialize gets associated with the
1306     // trap, and may be placed in a different (outer) loop, if the Allocate
1307     // is in a loop.  If (this is rare) the inner loop gets unrolled, then
1308     // there can be two Allocates to one Initialize.  The answer in all these
1309     // edge cases is safety first.  It is always safe to clear immediately
1310     // within an Allocate, and then (maybe or maybe not) clear some more later.
1311     if (!ZeroTLAB)
1312       rawmem = ClearArrayNode::clear_memory(control, rawmem, object,
1313                                             header_size, size_in_bytes,
1314                                             &_igvn);
1315   } else {
1316     if (!init->is_complete()) {
1317       // Try to win by zeroing only what the init does not store.
1318       // We can also try to do some peephole optimizations,
1319       // such as combining some adjacent subword stores.
1320       rawmem = init->complete_stores(control, rawmem, object,
1321                                      header_size, size_in_bytes, &_igvn);
1322     }
1323     // We have no more use for this link, since the AllocateNode goes away:
1324     init->set_req(InitializeNode::RawAddress, top());
1325     // (If we keep the link, it just confuses the register allocator,
1326     // who thinks he sees a real use of the address by the membar.)
1327   }
1328 
1329   return rawmem;
1330 }
1331 
1332 // Generate prefetch instructions for next allocations.
1333 Node* PhaseMacroExpand::prefetch_allocation(Node* i_o, Node*& needgc_false,
1334                                         Node*& contended_phi_rawmem,
1335                                         Node* old_eden_top, Node* new_eden_top,
1336                                         Node* length) {
1337    if( UseTLAB && AllocatePrefetchStyle == 2 ) {
1338       // Generate prefetch allocation with watermark check.
1339       // As an allocation hits the watermark, we will prefetch starting
1340       // at a "distance" away from watermark.
1341       enum { fall_in_path = 1, pf_path = 2 };
1342 
1343       Node *pf_region = new (C, 3) RegionNode(3);
1344       Node *pf_phi_rawmem = new (C, 3) PhiNode( pf_region, Type::MEMORY,
1345                                                 TypeRawPtr::BOTTOM );
1346       // I/O is used for Prefetch
1347       Node *pf_phi_abio = new (C, 3) PhiNode( pf_region, Type::ABIO );
1348 
1349       Node *thread = new (C, 1) ThreadLocalNode();
1350       transform_later(thread);
1351 
1352       Node *eden_pf_adr = new (C, 4) AddPNode( top()/*not oop*/, thread,
1353                    _igvn.MakeConX(in_bytes(JavaThread::tlab_pf_top_offset())) );
1354       transform_later(eden_pf_adr);
1355 
1356       Node *old_pf_wm = new (C, 3) LoadPNode( needgc_false,
1357                                    contended_phi_rawmem, eden_pf_adr,
1358                                    TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM );
1359       transform_later(old_pf_wm);
1360 
1361       // check against new_eden_top
1362       Node *need_pf_cmp = new (C, 3) CmpPNode( new_eden_top, old_pf_wm );
1363       transform_later(need_pf_cmp);
1364       Node *need_pf_bol = new (C, 2) BoolNode( need_pf_cmp, BoolTest::ge );
1365       transform_later(need_pf_bol);
1366       IfNode *need_pf_iff = new (C, 2) IfNode( needgc_false, need_pf_bol,
1367                                        PROB_UNLIKELY_MAG(4), COUNT_UNKNOWN );
1368       transform_later(need_pf_iff);
1369 
1370       // true node, add prefetchdistance
1371       Node *need_pf_true = new (C, 1) IfTrueNode( need_pf_iff );
1372       transform_later(need_pf_true);
1373 
1374       Node *need_pf_false = new (C, 1) IfFalseNode( need_pf_iff );
1375       transform_later(need_pf_false);
1376 
1377       Node *new_pf_wmt = new (C, 4) AddPNode( top(), old_pf_wm,
1378                                     _igvn.MakeConX(AllocatePrefetchDistance) );
1379       transform_later(new_pf_wmt );
1380       new_pf_wmt->set_req(0, need_pf_true);
1381 
1382       Node *store_new_wmt = new (C, 4) StorePNode( need_pf_true,
1383                                        contended_phi_rawmem, eden_pf_adr,
1384                                        TypeRawPtr::BOTTOM, new_pf_wmt );
1385       transform_later(store_new_wmt);
1386 
1387       // adding prefetches
1388       pf_phi_abio->init_req( fall_in_path, i_o );
1389 
1390       Node *prefetch_adr;
1391       Node *prefetch;
1392       uint lines = AllocatePrefetchDistance / AllocatePrefetchStepSize;
1393       uint step_size = AllocatePrefetchStepSize;
1394       uint distance = 0;
1395 
1396       for ( uint i = 0; i < lines; i++ ) {
1397         prefetch_adr = new (C, 4) AddPNode( old_pf_wm, new_pf_wmt,
1398                                             _igvn.MakeConX(distance) );
1399         transform_later(prefetch_adr);
1400         prefetch = new (C, 3) PrefetchWriteNode( i_o, prefetch_adr );
1401         transform_later(prefetch);
1402         distance += step_size;
1403         i_o = prefetch;
1404       }
1405       pf_phi_abio->set_req( pf_path, i_o );
1406 
1407       pf_region->init_req( fall_in_path, need_pf_false );
1408       pf_region->init_req( pf_path, need_pf_true );
1409 
1410       pf_phi_rawmem->init_req( fall_in_path, contended_phi_rawmem );
1411       pf_phi_rawmem->init_req( pf_path, store_new_wmt );
1412 
1413       transform_later(pf_region);
1414       transform_later(pf_phi_rawmem);
1415       transform_later(pf_phi_abio);
1416 
1417       needgc_false = pf_region;
1418       contended_phi_rawmem = pf_phi_rawmem;
1419       i_o = pf_phi_abio;
1420    } else if( AllocatePrefetchStyle > 0 ) {
1421       // Insert a prefetch for each allocation only on the fast-path
1422       Node *prefetch_adr;
1423       Node *prefetch;
1424       // Generate several prefetch instructions only for arrays.
1425       uint lines = (length != NULL) ? AllocatePrefetchLines : 1;
1426       uint step_size = AllocatePrefetchStepSize;
1427       uint distance = AllocatePrefetchDistance;
1428       for ( uint i = 0; i < lines; i++ ) {
1429         prefetch_adr = new (C, 4) AddPNode( old_eden_top, new_eden_top,
1430                                             _igvn.MakeConX(distance) );
1431         transform_later(prefetch_adr);
1432         prefetch = new (C, 3) PrefetchWriteNode( i_o, prefetch_adr );
1433         // Do not let it float too high, since if eden_top == eden_end,
1434         // both might be null.
1435         if( i == 0 ) { // Set control for first prefetch, next follows it
1436           prefetch->init_req(0, needgc_false);
1437         }
1438         transform_later(prefetch);
1439         distance += step_size;
1440         i_o = prefetch;
1441       }
1442    }
1443    return i_o;
1444 }
1445 
1446 
1447 void PhaseMacroExpand::expand_allocate(AllocateNode *alloc) {
1448   expand_allocate_common(alloc, NULL,
1449                          OptoRuntime::new_instance_Type(),
1450                          OptoRuntime::new_instance_Java());
1451 }
1452 
1453 void PhaseMacroExpand::expand_allocate_array(AllocateArrayNode *alloc) {
1454   Node* length = alloc->in(AllocateNode::ALength);
1455   expand_allocate_common(alloc, length,
1456                          OptoRuntime::new_array_Type(),
1457                          OptoRuntime::new_array_Java());
1458 }
1459 
1460 
1461 // we have determined that this lock/unlock can be eliminated, we simply
1462 // eliminate the node without expanding it.
1463 //
1464 // Note:  The membar's associated with the lock/unlock are currently not
1465 //        eliminated.  This should be investigated as a future enhancement.
1466 //
1467 bool PhaseMacroExpand::eliminate_locking_node(AbstractLockNode *alock) {
1468 
1469   if (!alock->is_eliminated()) {
1470     return false;
1471   }
1472   // Mark the box lock as eliminated if all correspondent locks are eliminated
1473   // to construct correct debug info.
1474   BoxLockNode* box = alock->box_node()->as_BoxLock();
1475   if (!box->is_eliminated()) {
1476     bool eliminate = true;
1477     for (DUIterator_Fast imax, i = box->fast_outs(imax); i < imax; i++) {
1478       Node *lck = box->fast_out(i);
1479       if (lck->is_Lock() && !lck->as_AbstractLock()->is_eliminated()) {
1480         eliminate = false;
1481         break;
1482       }
1483     }
1484     if (eliminate)
1485       box->set_eliminated();
1486   }
1487 
1488   #ifndef PRODUCT
1489   if (PrintEliminateLocks) {
1490     if (alock->is_Lock()) {
1491       tty->print_cr("++++ Eliminating: %d Lock", alock->_idx);
1492     } else {
1493       tty->print_cr("++++ Eliminating: %d Unlock", alock->_idx);
1494     }
1495   }
1496   #endif
1497 
1498   Node* mem  = alock->in(TypeFunc::Memory);
1499   Node* ctrl = alock->in(TypeFunc::Control);
1500 
1501   extract_call_projections(alock);
1502   // There are 2 projections from the lock.  The lock node will
1503   // be deleted when its last use is subsumed below.
1504   assert(alock->outcnt() == 2 &&
1505          _fallthroughproj != NULL &&
1506          _memproj_fallthrough != NULL,
1507          "Unexpected projections from Lock/Unlock");
1508 
1509   Node* fallthroughproj = _fallthroughproj;
1510   Node* memproj_fallthrough = _memproj_fallthrough;
1511 
1512   // The memory projection from a lock/unlock is RawMem
1513   // The input to a Lock is merged memory, so extract its RawMem input
1514   // (unless the MergeMem has been optimized away.)
1515   if (alock->is_Lock()) {
1516     // Seach for MemBarAcquire node and delete it also.
1517     MemBarNode* membar = fallthroughproj->unique_ctrl_out()->as_MemBar();
1518     assert(membar != NULL && membar->Opcode() == Op_MemBarAcquire, "");
1519     Node* ctrlproj = membar->proj_out(TypeFunc::Control);
1520     Node* memproj = membar->proj_out(TypeFunc::Memory);
1521     _igvn.hash_delete(ctrlproj);
1522     _igvn.subsume_node(ctrlproj, fallthroughproj);
1523     _igvn.hash_delete(memproj);
1524     _igvn.subsume_node(memproj, memproj_fallthrough);
1525   }
1526 
1527   // Seach for MemBarRelease node and delete it also.
1528   if (alock->is_Unlock() && ctrl != NULL && ctrl->is_Proj() &&
1529       ctrl->in(0)->is_MemBar()) {
1530     MemBarNode* membar = ctrl->in(0)->as_MemBar();
1531     assert(membar->Opcode() == Op_MemBarRelease &&
1532            mem->is_Proj() && membar == mem->in(0), "");
1533     _igvn.hash_delete(fallthroughproj);
1534     _igvn.subsume_node(fallthroughproj, ctrl);
1535     _igvn.hash_delete(memproj_fallthrough);
1536     _igvn.subsume_node(memproj_fallthrough, mem);
1537     fallthroughproj = ctrl;
1538     memproj_fallthrough = mem;
1539     ctrl = membar->in(TypeFunc::Control);
1540     mem  = membar->in(TypeFunc::Memory);
1541   }
1542 
1543   _igvn.hash_delete(fallthroughproj);
1544   _igvn.subsume_node(fallthroughproj, ctrl);
1545   _igvn.hash_delete(memproj_fallthrough);
1546   _igvn.subsume_node(memproj_fallthrough, mem);
1547   return true;
1548 }
1549 
1550 
1551 //------------------------------expand_lock_node----------------------
1552 void PhaseMacroExpand::expand_lock_node(LockNode *lock) {
1553 
1554   Node* ctrl = lock->in(TypeFunc::Control);
1555   Node* mem = lock->in(TypeFunc::Memory);
1556   Node* obj = lock->obj_node();
1557   Node* box = lock->box_node();
1558   Node* flock = lock->fastlock_node();
1559 
1560   // Make the merge point
1561   Node *region = new (C, 3) RegionNode(3);
1562 
1563   Node *bol = transform_later(new (C, 2) BoolNode(flock,BoolTest::ne));
1564   Node *iff = new (C, 2) IfNode( ctrl, bol, PROB_MIN, COUNT_UNKNOWN );
1565   // Optimize test; set region slot 2
1566   Node *slow_path = opt_iff(region,iff);
1567 
1568   // Make slow path call
1569   CallNode *call = make_slow_call( (CallNode *) lock, OptoRuntime::complete_monitor_enter_Type(), OptoRuntime::complete_monitor_locking_Java(), NULL, slow_path, obj, box );
1570 
1571   extract_call_projections(call);
1572 
1573   // Slow path can only throw asynchronous exceptions, which are always
1574   // de-opted.  So the compiler thinks the slow-call can never throw an
1575   // exception.  If it DOES throw an exception we would need the debug
1576   // info removed first (since if it throws there is no monitor).
1577   assert ( _ioproj_fallthrough == NULL && _ioproj_catchall == NULL &&
1578            _memproj_catchall == NULL && _catchallcatchproj == NULL, "Unexpected projection from Lock");
1579 
1580   // Capture slow path
1581   // disconnect fall-through projection from call and create a new one
1582   // hook up users of fall-through projection to region
1583   Node *slow_ctrl = _fallthroughproj->clone();
1584   transform_later(slow_ctrl);
1585   _igvn.hash_delete(_fallthroughproj);
1586   _fallthroughproj->disconnect_inputs(NULL);
1587   region->init_req(1, slow_ctrl);
1588   // region inputs are now complete
1589   transform_later(region);
1590   _igvn.subsume_node(_fallthroughproj, region);
1591 
1592   // create a Phi for the memory state
1593   Node *mem_phi = new (C, 3) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
1594   Node *memproj = transform_later( new (C, 1) ProjNode(call, TypeFunc::Memory) );
1595   mem_phi->init_req(1, memproj );
1596   mem_phi->init_req(2, mem);
1597   transform_later(mem_phi);
1598     _igvn.hash_delete(_memproj_fallthrough);
1599   _igvn.subsume_node(_memproj_fallthrough, mem_phi);
1600 
1601 
1602 }
1603 
1604 //------------------------------expand_unlock_node----------------------
1605 void PhaseMacroExpand::expand_unlock_node(UnlockNode *unlock) {
1606 
1607   Node* ctrl = unlock->in(TypeFunc::Control);
1608   Node* mem = unlock->in(TypeFunc::Memory);
1609   Node* obj = unlock->obj_node();
1610   Node* box = unlock->box_node();
1611 
1612   // No need for a null check on unlock
1613 
1614   // Make the merge point
1615   RegionNode *region = new (C, 3) RegionNode(3);
1616 
1617   FastUnlockNode *funlock = new (C, 3) FastUnlockNode( ctrl, obj, box );
1618   funlock = transform_later( funlock )->as_FastUnlock();
1619   Node *bol = transform_later(new (C, 2) BoolNode(funlock,BoolTest::ne));
1620   Node *iff = new (C, 2) IfNode( ctrl, bol, PROB_MIN, COUNT_UNKNOWN );
1621   // Optimize test; set region slot 2
1622   Node *slow_path = opt_iff(region,iff);
1623 
1624   CallNode *call = make_slow_call( (CallNode *) unlock, OptoRuntime::complete_monitor_exit_Type(), CAST_FROM_FN_PTR(address, SharedRuntime::complete_monitor_unlocking_C), "complete_monitor_unlocking_C", slow_path, obj, box );
1625 
1626   extract_call_projections(call);
1627 
1628   assert ( _ioproj_fallthrough == NULL && _ioproj_catchall == NULL &&
1629            _memproj_catchall == NULL && _catchallcatchproj == NULL, "Unexpected projection from Lock");
1630 
1631   // No exceptions for unlocking
1632   // Capture slow path
1633   // disconnect fall-through projection from call and create a new one
1634   // hook up users of fall-through projection to region
1635   Node *slow_ctrl = _fallthroughproj->clone();
1636   transform_later(slow_ctrl);
1637   _igvn.hash_delete(_fallthroughproj);
1638   _fallthroughproj->disconnect_inputs(NULL);
1639   region->init_req(1, slow_ctrl);
1640   // region inputs are now complete
1641   transform_later(region);
1642   _igvn.subsume_node(_fallthroughproj, region);
1643 
1644   // create a Phi for the memory state
1645   Node *mem_phi = new (C, 3) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
1646   Node *memproj = transform_later( new(C, 1) ProjNode(call, TypeFunc::Memory) );
1647   mem_phi->init_req(1, memproj );
1648   mem_phi->init_req(2, mem);
1649   transform_later(mem_phi);
1650     _igvn.hash_delete(_memproj_fallthrough);
1651   _igvn.subsume_node(_memproj_fallthrough, mem_phi);
1652 
1653 
1654 }
1655 
1656 //------------------------------expand_macro_nodes----------------------
1657 //  Returns true if a failure occurred.
1658 bool PhaseMacroExpand::expand_macro_nodes() {
1659   if (C->macro_count() == 0)
1660     return false;
1661   // attempt to eliminate allocations
1662   bool progress = true;
1663   while (progress) {
1664     progress = false;
1665     for (int i = C->macro_count(); i > 0; i--) {
1666       Node * n = C->macro_node(i-1);
1667       bool success = false;
1668       debug_only(int old_macro_count = C->macro_count(););
1669       switch (n->class_id()) {
1670       case Node::Class_Allocate:
1671       case Node::Class_AllocateArray:
1672         success = eliminate_allocate_node(n->as_Allocate());
1673         break;
1674       case Node::Class_Lock:
1675       case Node::Class_Unlock:
1676         success = eliminate_locking_node(n->as_AbstractLock());
1677         break;
1678       default:
1679         if (n->Opcode() == Op_Opaque1 || n->Opcode() == Op_Opaque2) {
1680           _igvn.add_users_to_worklist(n);
1681           _igvn.hash_delete(n);
1682           _igvn.subsume_node(n, n->in(1));
1683           success = true;
1684         } else {
1685           assert(false, "unknown node type in macro list");
1686         }
1687       }
1688       assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
1689       progress = progress || success;
1690     }
1691   }
1692   // Make sure expansion will not cause node limit to be exceeded.
1693   // Worst case is a macro node gets expanded into about 50 nodes.
1694   // Allow 50% more for optimization.
1695   if (C->check_node_count(C->macro_count() * 75, "out of nodes before macro expansion" ) )
1696     return true;
1697 
1698   // expand "macro" nodes
1699   // nodes are removed from the macro list as they are processed
1700   while (C->macro_count() > 0) {
1701     int macro_count = C->macro_count();
1702     Node * n = C->macro_node(macro_count-1);
1703     assert(n->is_macro(), "only macro nodes expected here");
1704     if (_igvn.type(n) == Type::TOP || n->in(0)->is_top() ) {
1705       // node is unreachable, so don't try to expand it
1706       C->remove_macro_node(n);
1707       continue;
1708     }
1709     switch (n->class_id()) {
1710     case Node::Class_Allocate:
1711       expand_allocate(n->as_Allocate());
1712       break;
1713     case Node::Class_AllocateArray:
1714       expand_allocate_array(n->as_AllocateArray());
1715       break;
1716     case Node::Class_Lock:
1717       expand_lock_node(n->as_Lock());
1718       break;
1719     case Node::Class_Unlock:
1720       expand_unlock_node(n->as_Unlock());
1721       break;
1722     default:
1723       assert(false, "unknown node type in macro list");
1724     }
1725     assert(C->macro_count() < macro_count, "must have deleted a node from macro list");
1726     if (C->failing())  return true;
1727   }
1728 
1729   _igvn.set_delay_transform(false);
1730   _igvn.optimize();
1731   return false;
1732 }