1 /*
   2  * Copyright (c) 2005, 2018, 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 "libadt/vectset.hpp"
  28 #include "opto/addnode.hpp"
  29 #include "opto/arraycopynode.hpp"
  30 #include "opto/callnode.hpp"
  31 #include "opto/castnode.hpp"
  32 #include "opto/cfgnode.hpp"
  33 #include "opto/compile.hpp"
  34 #include "opto/convertnode.hpp"
  35 #include "opto/graphKit.hpp"
  36 #include "opto/locknode.hpp"
  37 #include "opto/loopnode.hpp"
  38 #include "opto/macro.hpp"
  39 #include "opto/memnode.hpp"
  40 #include "opto/narrowptrnode.hpp"
  41 #include "opto/node.hpp"
  42 #include "opto/opaquenode.hpp"
  43 #include "opto/phaseX.hpp"
  44 #include "opto/rootnode.hpp"
  45 #include "opto/runtime.hpp"
  46 #include "opto/subnode.hpp"
  47 #include "opto/type.hpp"
  48 #include "runtime/sharedRuntime.hpp"
  49 
  50 
  51 //
  52 // Replace any references to "oldref" in inputs to "use" with "newref".
  53 // Returns the number of replacements made.
  54 //
  55 int PhaseMacroExpand::replace_input(Node *use, Node *oldref, Node *newref) {
  56   int nreplacements = 0;
  57   uint req = use->req();
  58   for (uint j = 0; j < use->len(); j++) {
  59     Node *uin = use->in(j);
  60     if (uin == oldref) {
  61       if (j < req)
  62         use->set_req(j, newref);
  63       else
  64         use->set_prec(j, newref);
  65       nreplacements++;
  66     } else if (j >= req && uin == NULL) {
  67       break;
  68     }
  69   }
  70   return nreplacements;
  71 }
  72 
  73 void PhaseMacroExpand::copy_call_debug_info(CallNode *oldcall, CallNode * newcall) {
  74   // Copy debug information and adjust JVMState information
  75   uint old_dbg_start = oldcall->tf()->domain()->cnt();
  76   uint new_dbg_start = newcall->tf()->domain()->cnt();
  77   int jvms_adj  = new_dbg_start - old_dbg_start;
  78   assert (new_dbg_start == newcall->req(), "argument count mismatch");
  79 
  80   // SafePointScalarObject node could be referenced several times in debug info.
  81   // Use Dict to record cloned nodes.
  82   Dict* sosn_map = new Dict(cmpkey,hashkey);
  83   for (uint i = old_dbg_start; i < oldcall->req(); i++) {
  84     Node* old_in = oldcall->in(i);
  85     // Clone old SafePointScalarObjectNodes, adjusting their field contents.
  86     if (old_in != NULL && old_in->is_SafePointScalarObject()) {
  87       SafePointScalarObjectNode* old_sosn = old_in->as_SafePointScalarObject();
  88       uint old_unique = C->unique();
  89       Node* new_in = old_sosn->clone(sosn_map);
  90       if (old_unique != C->unique()) { // New node?
  91         new_in->set_req(0, C->root()); // reset control edge
  92         new_in = transform_later(new_in); // Register new node.
  93       }
  94       old_in = new_in;
  95     }
  96     newcall->add_req(old_in);
  97   }
  98 
  99   // JVMS may be shared so clone it before we modify it
 100   newcall->set_jvms(oldcall->jvms() != NULL ? oldcall->jvms()->clone_deep(C) : NULL);
 101   for (JVMState *jvms = newcall->jvms(); jvms != NULL; jvms = jvms->caller()) {
 102     jvms->set_map(newcall);
 103     jvms->set_locoff(jvms->locoff()+jvms_adj);
 104     jvms->set_stkoff(jvms->stkoff()+jvms_adj);
 105     jvms->set_monoff(jvms->monoff()+jvms_adj);
 106     jvms->set_scloff(jvms->scloff()+jvms_adj);
 107     jvms->set_endoff(jvms->endoff()+jvms_adj);
 108   }
 109 }
 110 
 111 Node* PhaseMacroExpand::opt_bits_test(Node* ctrl, Node* region, int edge, Node* word, int mask, int bits, bool return_fast_path) {
 112   Node* cmp;
 113   if (mask != 0) {
 114     Node* and_node = transform_later(new AndXNode(word, MakeConX(mask)));
 115     cmp = transform_later(new CmpXNode(and_node, MakeConX(bits)));
 116   } else {
 117     cmp = word;
 118   }
 119   Node* bol = transform_later(new BoolNode(cmp, BoolTest::ne));
 120   IfNode* iff = new IfNode( ctrl, bol, PROB_MIN, COUNT_UNKNOWN );
 121   transform_later(iff);
 122 
 123   // Fast path taken.
 124   Node *fast_taken = transform_later(new IfFalseNode(iff));
 125 
 126   // Fast path not-taken, i.e. slow path
 127   Node *slow_taken = transform_later(new IfTrueNode(iff));
 128 
 129   if (return_fast_path) {
 130     region->init_req(edge, slow_taken); // Capture slow-control
 131     return fast_taken;
 132   } else {
 133     region->init_req(edge, fast_taken); // Capture fast-control
 134     return slow_taken;
 135   }
 136 }
 137 
 138 //--------------------copy_predefined_input_for_runtime_call--------------------
 139 void PhaseMacroExpand::copy_predefined_input_for_runtime_call(Node * ctrl, CallNode* oldcall, CallNode* call) {
 140   // Set fixed predefined input arguments
 141   call->init_req( TypeFunc::Control, ctrl );
 142   call->init_req( TypeFunc::I_O    , oldcall->in( TypeFunc::I_O) );
 143   call->init_req( TypeFunc::Memory , oldcall->in( TypeFunc::Memory ) ); // ?????
 144   call->init_req( TypeFunc::ReturnAdr, oldcall->in( TypeFunc::ReturnAdr ) );
 145   call->init_req( TypeFunc::FramePtr, oldcall->in( TypeFunc::FramePtr ) );
 146 }
 147 
 148 //------------------------------make_slow_call---------------------------------
 149 CallNode* PhaseMacroExpand::make_slow_call(CallNode *oldcall, const TypeFunc* slow_call_type,
 150                                            address slow_call, const char* leaf_name, Node* slow_path,
 151                                            Node* parm0, Node* parm1, Node* parm2) {
 152 
 153   // Slow-path call
 154  CallNode *call = leaf_name
 155    ? (CallNode*)new CallLeafNode      ( slow_call_type, slow_call, leaf_name, TypeRawPtr::BOTTOM )
 156    : (CallNode*)new CallStaticJavaNode( slow_call_type, slow_call, OptoRuntime::stub_name(slow_call), oldcall->jvms()->bci(), TypeRawPtr::BOTTOM );
 157 
 158   // Slow path call has no side-effects, uses few values
 159   copy_predefined_input_for_runtime_call(slow_path, oldcall, call );
 160   if (parm0 != NULL)  call->init_req(TypeFunc::Parms+0, parm0);
 161   if (parm1 != NULL)  call->init_req(TypeFunc::Parms+1, parm1);
 162   if (parm2 != NULL)  call->init_req(TypeFunc::Parms+2, parm2);
 163   copy_call_debug_info(oldcall, call);
 164   call->set_cnt(PROB_UNLIKELY_MAG(4));  // Same effect as RC_UNCOMMON.
 165   _igvn.replace_node(oldcall, call);
 166   transform_later(call);
 167 
 168   return call;
 169 }
 170 
 171 void PhaseMacroExpand::extract_call_projections(CallNode *call) {
 172   _fallthroughproj = NULL;
 173   _fallthroughcatchproj = NULL;
 174   _ioproj_fallthrough = NULL;
 175   _ioproj_catchall = NULL;
 176   _catchallcatchproj = NULL;
 177   _memproj_fallthrough = NULL;
 178   _memproj_catchall = NULL;
 179   _resproj = NULL;
 180   for (DUIterator_Fast imax, i = call->fast_outs(imax); i < imax; i++) {
 181     ProjNode *pn = call->fast_out(i)->as_Proj();
 182     switch (pn->_con) {
 183       case TypeFunc::Control:
 184       {
 185         // For Control (fallthrough) and I_O (catch_all_index) we have CatchProj -> Catch -> Proj
 186         _fallthroughproj = pn;
 187         DUIterator_Fast jmax, j = pn->fast_outs(jmax);
 188         const Node *cn = pn->fast_out(j);
 189         if (cn->is_Catch()) {
 190           ProjNode *cpn = NULL;
 191           for (DUIterator_Fast kmax, k = cn->fast_outs(kmax); k < kmax; k++) {
 192             cpn = cn->fast_out(k)->as_Proj();
 193             assert(cpn->is_CatchProj(), "must be a CatchProjNode");
 194             if (cpn->_con == CatchProjNode::fall_through_index)
 195               _fallthroughcatchproj = cpn;
 196             else {
 197               assert(cpn->_con == CatchProjNode::catch_all_index, "must be correct index.");
 198               _catchallcatchproj = cpn;
 199             }
 200           }
 201         }
 202         break;
 203       }
 204       case TypeFunc::I_O:
 205         if (pn->_is_io_use)
 206           _ioproj_catchall = pn;
 207         else
 208           _ioproj_fallthrough = pn;
 209         break;
 210       case TypeFunc::Memory:
 211         if (pn->_is_io_use)
 212           _memproj_catchall = pn;
 213         else
 214           _memproj_fallthrough = pn;
 215         break;
 216       case TypeFunc::Parms:
 217         _resproj = pn;
 218         break;
 219       default:
 220         assert(false, "unexpected projection from allocation node.");
 221     }
 222   }
 223 
 224 }
 225 
 226 // Eliminate a card mark sequence.  p2x is a ConvP2XNode
 227 void PhaseMacroExpand::eliminate_card_mark(Node* p2x) {
 228   assert(p2x->Opcode() == Op_CastP2X, "ConvP2XNode required");
 229   if (!UseG1GC) {
 230     // vanilla/CMS post barrier
 231     Node *shift = p2x->unique_out();
 232     Node *addp = shift->unique_out();
 233     for (DUIterator_Last jmin, j = addp->last_outs(jmin); j >= jmin; --j) {
 234       Node *mem = addp->last_out(j);
 235       if (UseCondCardMark && mem->is_Load()) {
 236         assert(mem->Opcode() == Op_LoadB, "unexpected code shape");
 237         // The load is checking if the card has been written so
 238         // replace it with zero to fold the test.
 239         _igvn.replace_node(mem, intcon(0));
 240         continue;
 241       }
 242       assert(mem->is_Store(), "store required");
 243       _igvn.replace_node(mem, mem->in(MemNode::Memory));
 244     }
 245   } else {
 246     // G1 pre/post barriers
 247     assert(p2x->outcnt() <= 2, "expects 1 or 2 users: Xor and URShift nodes");
 248     // It could be only one user, URShift node, in Object.clone() intrinsic
 249     // but the new allocation is passed to arraycopy stub and it could not
 250     // be scalar replaced. So we don't check the case.
 251 
 252     // An other case of only one user (Xor) is when the value check for NULL
 253     // in G1 post barrier is folded after CCP so the code which used URShift
 254     // is removed.
 255 
 256     // Take Region node before eliminating post barrier since it also
 257     // eliminates CastP2X node when it has only one user.
 258     Node* this_region = p2x->in(0);
 259     assert(this_region != NULL, "");
 260 
 261     // Remove G1 post barrier.
 262 
 263     // Search for CastP2X->Xor->URShift->Cmp path which
 264     // checks if the store done to a different from the value's region.
 265     // And replace Cmp with #0 (false) to collapse G1 post barrier.
 266     Node* xorx = p2x->find_out_with(Op_XorX);
 267     if (xorx != NULL) {
 268       Node* shift = xorx->unique_out();
 269       Node* cmpx = shift->unique_out();
 270       assert(cmpx->is_Cmp() && cmpx->unique_out()->is_Bool() &&
 271       cmpx->unique_out()->as_Bool()->_test._test == BoolTest::ne,
 272       "missing region check in G1 post barrier");
 273       _igvn.replace_node(cmpx, makecon(TypeInt::CC_EQ));
 274 
 275       // Remove G1 pre barrier.
 276 
 277       // Search "if (marking != 0)" check and set it to "false".
 278       // There is no G1 pre barrier if previous stored value is NULL
 279       // (for example, after initialization).
 280       if (this_region->is_Region() && this_region->req() == 3) {
 281         int ind = 1;
 282         if (!this_region->in(ind)->is_IfFalse()) {
 283           ind = 2;
 284         }
 285         if (this_region->in(ind)->is_IfFalse() &&
 286             this_region->in(ind)->in(0)->Opcode() == Op_If) {
 287           Node* bol = this_region->in(ind)->in(0)->in(1);
 288           assert(bol->is_Bool(), "");
 289           cmpx = bol->in(1);
 290           if (bol->as_Bool()->_test._test == BoolTest::ne &&
 291               cmpx->is_Cmp() && cmpx->in(2) == intcon(0) &&
 292               cmpx->in(1)->is_Load()) {
 293             Node* adr = cmpx->in(1)->as_Load()->in(MemNode::Address);
 294             const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() +
 295                                                 SATBMarkQueue::byte_offset_of_active());
 296             if (adr->is_AddP() && adr->in(AddPNode::Base) == top() &&
 297                 adr->in(AddPNode::Address)->Opcode() == Op_ThreadLocal &&
 298                 adr->in(AddPNode::Offset) == MakeConX(marking_offset)) {
 299               _igvn.replace_node(cmpx, makecon(TypeInt::CC_EQ));
 300             }
 301           }
 302         }
 303       }
 304     } else {
 305       assert(!GraphKit::use_ReduceInitialCardMarks(), "can only happen with card marking");
 306       // This is a G1 post barrier emitted by the Object.clone() intrinsic.
 307       // Search for the CastP2X->URShiftX->AddP->LoadB->Cmp path which checks if the card
 308       // is marked as young_gen and replace the Cmp with 0 (false) to collapse the barrier.
 309       Node* shift = p2x->find_out_with(Op_URShiftX);
 310       assert(shift != NULL, "missing G1 post barrier");
 311       Node* addp = shift->unique_out();
 312       Node* load = addp->find_out_with(Op_LoadB);
 313       assert(load != NULL, "missing G1 post barrier");
 314       Node* cmpx = load->unique_out();
 315       assert(cmpx->is_Cmp() && cmpx->unique_out()->is_Bool() &&
 316              cmpx->unique_out()->as_Bool()->_test._test == BoolTest::ne,
 317              "missing card value check in G1 post barrier");
 318       _igvn.replace_node(cmpx, makecon(TypeInt::CC_EQ));
 319       // There is no G1 pre barrier in this case
 320     }
 321     // Now CastP2X can be removed since it is used only on dead path
 322     // which currently still alive until igvn optimize it.
 323     assert(p2x->outcnt() == 0 || p2x->unique_out()->Opcode() == Op_URShiftX, "");
 324     _igvn.replace_node(p2x, top());
 325   }
 326 }
 327 
 328 // Search for a memory operation for the specified memory slice.
 329 static Node *scan_mem_chain(Node *mem, int alias_idx, int offset, Node *start_mem, Node *alloc, PhaseGVN *phase) {
 330   Node *orig_mem = mem;
 331   Node *alloc_mem = alloc->in(TypeFunc::Memory);
 332   const TypeOopPtr *tinst = phase->C->get_adr_type(alias_idx)->isa_oopptr();
 333   while (true) {
 334     if (mem == alloc_mem || mem == start_mem ) {
 335       return mem;  // hit one of our sentinels
 336     } else if (mem->is_MergeMem()) {
 337       mem = mem->as_MergeMem()->memory_at(alias_idx);
 338     } else if (mem->is_Proj() && mem->as_Proj()->_con == TypeFunc::Memory) {
 339       Node *in = mem->in(0);
 340       // we can safely skip over safepoints, calls, locks and membars because we
 341       // already know that the object is safe to eliminate.
 342       if (in->is_Initialize() && in->as_Initialize()->allocation() == alloc) {
 343         return in;
 344       } else if (in->is_Call()) {
 345         CallNode *call = in->as_Call();
 346         if (call->may_modify(tinst, phase)) {
 347           assert(call->is_ArrayCopy(), "ArrayCopy is the only call node that doesn't make allocation escape");
 348           if (call->as_ArrayCopy()->modifies(offset, offset, phase, false)) {
 349             return in;
 350           }
 351         }
 352         mem = in->in(TypeFunc::Memory);
 353       } else if (in->is_MemBar()) {
 354         ArrayCopyNode* ac = NULL;
 355         if (ArrayCopyNode::may_modify(tinst, in->as_MemBar(), phase, ac)) {
 356           assert(ac != NULL && ac->is_clonebasic(), "Only basic clone is a non escaping clone");
 357           return ac;
 358         }
 359         mem = in->in(TypeFunc::Memory);
 360       } else {
 361         assert(false, "unexpected projection");
 362       }
 363     } else if (mem->is_Store()) {
 364       const TypePtr* atype = mem->as_Store()->adr_type();
 365       int adr_idx = phase->C->get_alias_index(atype);
 366       if (adr_idx == alias_idx) {
 367         assert(atype->isa_oopptr(), "address type must be oopptr");
 368         int adr_offset = atype->offset();
 369         uint adr_iid = atype->is_oopptr()->instance_id();
 370         // Array elements references have the same alias_idx
 371         // but different offset and different instance_id.
 372         if (adr_offset == offset && adr_iid == alloc->_idx)
 373           return mem;
 374       } else {
 375         assert(adr_idx == Compile::AliasIdxRaw, "address must match or be raw");
 376       }
 377       mem = mem->in(MemNode::Memory);
 378     } else if (mem->is_ClearArray()) {
 379       if (!ClearArrayNode::step_through(&mem, alloc->_idx, phase)) {
 380         // Can not bypass initialization of the instance
 381         // we are looking.
 382         debug_only(intptr_t offset;)
 383         assert(alloc == AllocateNode::Ideal_allocation(mem->in(3), phase, offset), "sanity");
 384         InitializeNode* init = alloc->as_Allocate()->initialization();
 385         // We are looking for stored value, return Initialize node
 386         // or memory edge from Allocate node.
 387         if (init != NULL)
 388           return init;
 389         else
 390           return alloc->in(TypeFunc::Memory); // It will produce zero value (see callers).
 391       }
 392       // Otherwise skip it (the call updated 'mem' value).
 393     } else if (mem->Opcode() == Op_SCMemProj) {
 394       mem = mem->in(0);
 395       Node* adr = NULL;
 396       if (mem->is_LoadStore()) {
 397         adr = mem->in(MemNode::Address);
 398       } else {
 399         assert(mem->Opcode() == Op_EncodeISOArray ||
 400                mem->Opcode() == Op_StrCompressedCopy, "sanity");
 401         adr = mem->in(3); // Destination array
 402       }
 403       const TypePtr* atype = adr->bottom_type()->is_ptr();
 404       int adr_idx = phase->C->get_alias_index(atype);
 405       if (adr_idx == alias_idx) {
 406         DEBUG_ONLY(mem->dump();)
 407         assert(false, "Object is not scalar replaceable if a LoadStore node accesses its field");
 408         return NULL;
 409       }
 410       mem = mem->in(MemNode::Memory);
 411    } else if (mem->Opcode() == Op_StrInflatedCopy) {
 412       Node* adr = mem->in(3); // Destination array
 413       const TypePtr* atype = adr->bottom_type()->is_ptr();
 414       int adr_idx = phase->C->get_alias_index(atype);
 415       if (adr_idx == alias_idx) {
 416         DEBUG_ONLY(mem->dump();)
 417         assert(false, "Object is not scalar replaceable if a StrInflatedCopy node accesses its field");
 418         return NULL;
 419       }
 420       mem = mem->in(MemNode::Memory);
 421     } else {
 422       return mem;
 423     }
 424     assert(mem != orig_mem, "dead memory loop");
 425   }
 426 }
 427 
 428 // Generate loads from source of the arraycopy for fields of
 429 // destination needed at a deoptimization point
 430 Node* PhaseMacroExpand::make_arraycopy_load(ArrayCopyNode* ac, intptr_t offset, Node* ctl, Node* mem, BasicType ft, const Type *ftype, AllocateNode *alloc) {
 431   BasicType bt = ft;
 432   const Type *type = ftype;
 433   if (ft == T_NARROWOOP) {
 434     bt = T_OBJECT;
 435     type = ftype->make_oopptr();
 436   }
 437   Node* res = NULL;
 438   if (ac->is_clonebasic()) {
 439     Node* base = ac->in(ArrayCopyNode::Src)->in(AddPNode::Base);
 440     Node* adr = _igvn.transform(new AddPNode(base, base, MakeConX(offset)));
 441     const TypePtr* adr_type = _igvn.type(base)->is_ptr()->add_offset(offset);
 442     res = LoadNode::make(_igvn, ctl, mem, adr, adr_type, type, bt, MemNode::unordered, LoadNode::Pinned);
 443   } else {
 444     if (ac->modifies(offset, offset, &_igvn, true)) {
 445       assert(ac->in(ArrayCopyNode::Dest) == alloc->result_cast(), "arraycopy destination should be allocation's result");
 446       uint shift  = exact_log2(type2aelembytes(bt));
 447       Node* diff = _igvn.transform(new SubINode(ac->in(ArrayCopyNode::SrcPos), ac->in(ArrayCopyNode::DestPos)));
 448 #ifdef _LP64
 449       diff = _igvn.transform(new ConvI2LNode(diff));
 450 #endif
 451       diff = _igvn.transform(new LShiftXNode(diff, intcon(shift)));
 452 
 453       Node* off = _igvn.transform(new AddXNode(MakeConX(offset), diff));
 454       Node* base = ac->in(ArrayCopyNode::Src);
 455       Node* adr = _igvn.transform(new AddPNode(base, base, off));
 456       const TypePtr* adr_type = _igvn.type(base)->is_ptr()->add_offset(offset);
 457       res = LoadNode::make(_igvn, ctl, mem, adr, adr_type, type, bt, MemNode::unordered, LoadNode::Pinned);
 458     }
 459   }
 460   if (res != NULL) {
 461     res = _igvn.transform(res);
 462     if (ftype->isa_narrowoop()) {
 463       // PhaseMacroExpand::scalar_replacement adds DecodeN nodes
 464       res = _igvn.transform(new EncodePNode(res, ftype));
 465     }
 466     return res;
 467   }
 468   return NULL;
 469 }
 470 
 471 //
 472 // Given a Memory Phi, compute a value Phi containing the values from stores
 473 // on the input paths.
 474 // Note: this function is recursive, its depth is limited by the "level" argument
 475 // Returns the computed Phi, or NULL if it cannot compute it.
 476 Node *PhaseMacroExpand::value_from_mem_phi(Node *mem, BasicType ft, const Type *phi_type, const TypeOopPtr *adr_t, AllocateNode *alloc, Node_Stack *value_phis, int level) {
 477   assert(mem->is_Phi(), "sanity");
 478   int alias_idx = C->get_alias_index(adr_t);
 479   int offset = adr_t->offset();
 480   int instance_id = adr_t->instance_id();
 481 
 482   // Check if an appropriate value phi already exists.
 483   Node* region = mem->in(0);
 484   for (DUIterator_Fast kmax, k = region->fast_outs(kmax); k < kmax; k++) {
 485     Node* phi = region->fast_out(k);
 486     if (phi->is_Phi() && phi != mem &&
 487         phi->as_Phi()->is_same_inst_field(phi_type, (int)mem->_idx, instance_id, alias_idx, offset)) {
 488       return phi;
 489     }
 490   }
 491   // Check if an appropriate new value phi already exists.
 492   Node* new_phi = value_phis->find(mem->_idx);
 493   if (new_phi != NULL)
 494     return new_phi;
 495 
 496   if (level <= 0) {
 497     return NULL; // Give up: phi tree too deep
 498   }
 499   Node *start_mem = C->start()->proj_out_or_null(TypeFunc::Memory);
 500   Node *alloc_mem = alloc->in(TypeFunc::Memory);
 501 
 502   uint length = mem->req();
 503   GrowableArray <Node *> values(length, length, NULL, false);
 504 
 505   // create a new Phi for the value
 506   PhiNode *phi = new PhiNode(mem->in(0), phi_type, NULL, mem->_idx, instance_id, alias_idx, offset);
 507   transform_later(phi);
 508   value_phis->push(phi, mem->_idx);
 509 
 510   for (uint j = 1; j < length; j++) {
 511     Node *in = mem->in(j);
 512     if (in == NULL || in->is_top()) {
 513       values.at_put(j, in);
 514     } else  {
 515       Node *val = scan_mem_chain(in, alias_idx, offset, start_mem, alloc, &_igvn);
 516       if (val == start_mem || val == alloc_mem) {
 517         // hit a sentinel, return appropriate 0 value
 518         values.at_put(j, _igvn.zerocon(ft));
 519         continue;
 520       }
 521       if (val->is_Initialize()) {
 522         val = val->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn);
 523       }
 524       if (val == NULL) {
 525         return NULL;  // can't find a value on this path
 526       }
 527       if (val == mem) {
 528         values.at_put(j, mem);
 529       } else if (val->is_Store()) {
 530         values.at_put(j, val->in(MemNode::ValueIn));
 531       } else if(val->is_Proj() && val->in(0) == alloc) {
 532         values.at_put(j, _igvn.zerocon(ft));
 533       } else if (val->is_Phi()) {
 534         val = value_from_mem_phi(val, ft, phi_type, adr_t, alloc, value_phis, level-1);
 535         if (val == NULL) {
 536           return NULL;
 537         }
 538         values.at_put(j, val);
 539       } else if (val->Opcode() == Op_SCMemProj) {
 540         assert(val->in(0)->is_LoadStore() ||
 541                val->in(0)->Opcode() == Op_EncodeISOArray ||
 542                val->in(0)->Opcode() == Op_StrCompressedCopy, "sanity");
 543         assert(false, "Object is not scalar replaceable if a LoadStore node accesses its field");
 544         return NULL;
 545       } else if (val->is_ArrayCopy()) {
 546         Node* res = make_arraycopy_load(val->as_ArrayCopy(), offset, val->in(0), val->in(TypeFunc::Memory), ft, phi_type, alloc);
 547         if (res == NULL) {
 548           return NULL;
 549         }
 550         values.at_put(j, res);
 551       } else {
 552 #ifdef ASSERT
 553         val->dump();
 554         assert(false, "unknown node on this path");
 555 #endif
 556         return NULL;  // unknown node on this path
 557       }
 558     }
 559   }
 560   // Set Phi's inputs
 561   for (uint j = 1; j < length; j++) {
 562     if (values.at(j) == mem) {
 563       phi->init_req(j, phi);
 564     } else {
 565       phi->init_req(j, values.at(j));
 566     }
 567   }
 568   return phi;
 569 }
 570 
 571 // Search the last value stored into the object's field.
 572 Node *PhaseMacroExpand::value_from_mem(Node *sfpt_mem, Node *sfpt_ctl, BasicType ft, const Type *ftype, const TypeOopPtr *adr_t, AllocateNode *alloc) {
 573   assert(adr_t->is_known_instance_field(), "instance required");
 574   int instance_id = adr_t->instance_id();
 575   assert((uint)instance_id == alloc->_idx, "wrong allocation");
 576 
 577   int alias_idx = C->get_alias_index(adr_t);
 578   int offset = adr_t->offset();
 579   Node *start_mem = C->start()->proj_out_or_null(TypeFunc::Memory);
 580   Node *alloc_ctrl = alloc->in(TypeFunc::Control);
 581   Node *alloc_mem = alloc->in(TypeFunc::Memory);
 582   Arena *a = Thread::current()->resource_area();
 583   VectorSet visited(a);
 584 
 585 
 586   bool done = sfpt_mem == alloc_mem;
 587   Node *mem = sfpt_mem;
 588   while (!done) {
 589     if (visited.test_set(mem->_idx)) {
 590       return NULL;  // found a loop, give up
 591     }
 592     mem = scan_mem_chain(mem, alias_idx, offset, start_mem, alloc, &_igvn);
 593     if (mem == start_mem || mem == alloc_mem) {
 594       done = true;  // hit a sentinel, return appropriate 0 value
 595     } else if (mem->is_Initialize()) {
 596       mem = mem->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn);
 597       if (mem == NULL) {
 598         done = true; // Something go wrong.
 599       } else if (mem->is_Store()) {
 600         const TypePtr* atype = mem->as_Store()->adr_type();
 601         assert(C->get_alias_index(atype) == Compile::AliasIdxRaw, "store is correct memory slice");
 602         done = true;
 603       }
 604     } else if (mem->is_Store()) {
 605       const TypeOopPtr* atype = mem->as_Store()->adr_type()->isa_oopptr();
 606       assert(atype != NULL, "address type must be oopptr");
 607       assert(C->get_alias_index(atype) == alias_idx &&
 608              atype->is_known_instance_field() && atype->offset() == offset &&
 609              atype->instance_id() == instance_id, "store is correct memory slice");
 610       done = true;
 611     } else if (mem->is_Phi()) {
 612       // try to find a phi's unique input
 613       Node *unique_input = NULL;
 614       Node *top = C->top();
 615       for (uint i = 1; i < mem->req(); i++) {
 616         Node *n = scan_mem_chain(mem->in(i), alias_idx, offset, start_mem, alloc, &_igvn);
 617         if (n == NULL || n == top || n == mem) {
 618           continue;
 619         } else if (unique_input == NULL) {
 620           unique_input = n;
 621         } else if (unique_input != n) {
 622           unique_input = top;
 623           break;
 624         }
 625       }
 626       if (unique_input != NULL && unique_input != top) {
 627         mem = unique_input;
 628       } else {
 629         done = true;
 630       }
 631     } else if (mem->is_ArrayCopy()) {
 632       done = true;
 633     } else {
 634       assert(false, "unexpected node");
 635     }
 636   }
 637   if (mem != NULL) {
 638     if (mem == start_mem || mem == alloc_mem) {
 639       // hit a sentinel, return appropriate 0 value
 640       return _igvn.zerocon(ft);
 641     } else if (mem->is_Store()) {
 642       return mem->in(MemNode::ValueIn);
 643     } else if (mem->is_Phi()) {
 644       // attempt to produce a Phi reflecting the values on the input paths of the Phi
 645       Node_Stack value_phis(a, 8);
 646       Node * phi = value_from_mem_phi(mem, ft, ftype, adr_t, alloc, &value_phis, ValueSearchLimit);
 647       if (phi != NULL) {
 648         return phi;
 649       } else {
 650         // Kill all new Phis
 651         while(value_phis.is_nonempty()) {
 652           Node* n = value_phis.node();
 653           _igvn.replace_node(n, C->top());
 654           value_phis.pop();
 655         }
 656       }
 657     } else if (mem->is_ArrayCopy()) {
 658       Node* ctl = mem->in(0);
 659       Node* m = mem->in(TypeFunc::Memory);
 660       if (sfpt_ctl->is_Proj() && sfpt_ctl->as_Proj()->is_uncommon_trap_proj(Deoptimization::Reason_none)) {
 661         // pin the loads in the uncommon trap path
 662         ctl = sfpt_ctl;
 663         m = sfpt_mem;
 664       }
 665       return make_arraycopy_load(mem->as_ArrayCopy(), offset, ctl, m, ft, ftype, alloc);
 666     }
 667   }
 668   // Something go wrong.
 669   return NULL;
 670 }
 671 
 672 // Check the possibility of scalar replacement.
 673 bool PhaseMacroExpand::can_eliminate_allocation(AllocateNode *alloc, GrowableArray <SafePointNode *>& safepoints) {
 674   //  Scan the uses of the allocation to check for anything that would
 675   //  prevent us from eliminating it.
 676   NOT_PRODUCT( const char* fail_eliminate = NULL; )
 677   DEBUG_ONLY( Node* disq_node = NULL; )
 678   bool  can_eliminate = true;
 679 
 680   Node* res = alloc->result_cast();
 681   const TypeOopPtr* res_type = NULL;
 682   if (res == NULL) {
 683     // All users were eliminated.
 684   } else if (!res->is_CheckCastPP()) {
 685     NOT_PRODUCT(fail_eliminate = "Allocation does not have unique CheckCastPP";)
 686     can_eliminate = false;
 687   } else {
 688     res_type = _igvn.type(res)->isa_oopptr();
 689     if (res_type == NULL) {
 690       NOT_PRODUCT(fail_eliminate = "Neither instance or array allocation";)
 691       can_eliminate = false;
 692     } else if (res_type->isa_aryptr()) {
 693       int length = alloc->in(AllocateNode::ALength)->find_int_con(-1);
 694       if (length < 0) {
 695         NOT_PRODUCT(fail_eliminate = "Array's size is not constant";)
 696         can_eliminate = false;
 697       }
 698     }
 699   }
 700 
 701   if (can_eliminate && res != NULL) {
 702     for (DUIterator_Fast jmax, j = res->fast_outs(jmax);
 703                                j < jmax && can_eliminate; j++) {
 704       Node* use = res->fast_out(j);
 705 
 706       if (use->is_AddP()) {
 707         const TypePtr* addp_type = _igvn.type(use)->is_ptr();
 708         int offset = addp_type->offset();
 709 
 710         if (offset == Type::OffsetTop || offset == Type::OffsetBot) {
 711           NOT_PRODUCT(fail_eliminate = "Undefined field referrence";)
 712           can_eliminate = false;
 713           break;
 714         }
 715         for (DUIterator_Fast kmax, k = use->fast_outs(kmax);
 716                                    k < kmax && can_eliminate; k++) {
 717           Node* n = use->fast_out(k);
 718           if (!n->is_Store() && n->Opcode() != Op_CastP2X &&
 719               !(n->is_ArrayCopy() &&
 720                 n->as_ArrayCopy()->is_clonebasic() &&
 721                 n->in(ArrayCopyNode::Dest) == use)) {
 722             DEBUG_ONLY(disq_node = n;)
 723             if (n->is_Load() || n->is_LoadStore()) {
 724               NOT_PRODUCT(fail_eliminate = "Field load";)
 725             } else {
 726               NOT_PRODUCT(fail_eliminate = "Not store field referrence";)
 727             }
 728             can_eliminate = false;
 729           }
 730         }
 731       } else if (use->is_ArrayCopy() &&
 732                  (use->as_ArrayCopy()->is_arraycopy_validated() ||
 733                   use->as_ArrayCopy()->is_copyof_validated() ||
 734                   use->as_ArrayCopy()->is_copyofrange_validated()) &&
 735                  use->in(ArrayCopyNode::Dest) == res) {
 736         // ok to eliminate
 737       } else if (use->is_SafePoint()) {
 738         SafePointNode* sfpt = use->as_SafePoint();
 739         if (sfpt->is_Call() && sfpt->as_Call()->has_non_debug_use(res)) {
 740           // Object is passed as argument.
 741           DEBUG_ONLY(disq_node = use;)
 742           NOT_PRODUCT(fail_eliminate = "Object is passed as argument";)
 743           can_eliminate = false;
 744         }
 745         Node* sfptMem = sfpt->memory();
 746         if (sfptMem == NULL || sfptMem->is_top()) {
 747           DEBUG_ONLY(disq_node = use;)
 748           NOT_PRODUCT(fail_eliminate = "NULL or TOP memory";)
 749           can_eliminate = false;
 750         } else {
 751           safepoints.append_if_missing(sfpt);
 752         }
 753       } else if (use->Opcode() != Op_CastP2X) { // CastP2X is used by card mark
 754         if (use->is_Phi()) {
 755           if (use->outcnt() == 1 && use->unique_out()->Opcode() == Op_Return) {
 756             NOT_PRODUCT(fail_eliminate = "Object is return value";)
 757           } else {
 758             NOT_PRODUCT(fail_eliminate = "Object is referenced by Phi";)
 759           }
 760           DEBUG_ONLY(disq_node = use;)
 761         } else {
 762           if (use->Opcode() == Op_Return) {
 763             NOT_PRODUCT(fail_eliminate = "Object is return value";)
 764           }else {
 765             NOT_PRODUCT(fail_eliminate = "Object is referenced by node";)
 766           }
 767           DEBUG_ONLY(disq_node = use;)
 768         }
 769         can_eliminate = false;
 770       } else {
 771         assert(use->Opcode() == Op_CastP2X, "should be");
 772         assert(!use->has_out_with(Op_OrL), "should have been removed because oop is never null");
 773       }
 774     }
 775   }
 776 
 777 #ifndef PRODUCT
 778   if (PrintEliminateAllocations) {
 779     if (can_eliminate) {
 780       tty->print("Scalar ");
 781       if (res == NULL)
 782         alloc->dump();
 783       else
 784         res->dump();
 785     } else if (alloc->_is_scalar_replaceable) {
 786       tty->print("NotScalar (%s)", fail_eliminate);
 787       if (res == NULL)
 788         alloc->dump();
 789       else
 790         res->dump();
 791 #ifdef ASSERT
 792       if (disq_node != NULL) {
 793           tty->print("  >>>> ");
 794           disq_node->dump();
 795       }
 796 #endif /*ASSERT*/
 797     }
 798   }
 799 #endif
 800   return can_eliminate;
 801 }
 802 
 803 // Do scalar replacement.
 804 bool PhaseMacroExpand::scalar_replacement(AllocateNode *alloc, GrowableArray <SafePointNode *>& safepoints) {
 805   GrowableArray <SafePointNode *> safepoints_done;
 806 
 807   ciKlass* klass = NULL;
 808   ciInstanceKlass* iklass = NULL;
 809   int nfields = 0;
 810   int array_base = 0;
 811   int element_size = 0;
 812   BasicType basic_elem_type = T_ILLEGAL;
 813   ciType* elem_type = NULL;
 814 
 815   Node* res = alloc->result_cast();
 816   assert(res == NULL || res->is_CheckCastPP(), "unexpected AllocateNode result");
 817   const TypeOopPtr* res_type = NULL;
 818   if (res != NULL) { // Could be NULL when there are no users
 819     res_type = _igvn.type(res)->isa_oopptr();
 820   }
 821 
 822   if (res != NULL) {
 823     klass = res_type->klass();
 824     if (res_type->isa_instptr()) {
 825       // find the fields of the class which will be needed for safepoint debug information
 826       assert(klass->is_instance_klass(), "must be an instance klass.");
 827       iklass = klass->as_instance_klass();
 828       nfields = iklass->nof_nonstatic_fields();
 829     } else {
 830       // find the array's elements which will be needed for safepoint debug information
 831       nfields = alloc->in(AllocateNode::ALength)->find_int_con(-1);
 832       assert(klass->is_array_klass() && nfields >= 0, "must be an array klass.");
 833       elem_type = klass->as_array_klass()->element_type();
 834       basic_elem_type = elem_type->basic_type();
 835       array_base = arrayOopDesc::base_offset_in_bytes(basic_elem_type);
 836       element_size = type2aelembytes(basic_elem_type);
 837     }
 838   }
 839   //
 840   // Process the safepoint uses
 841   //
 842   while (safepoints.length() > 0) {
 843     SafePointNode* sfpt = safepoints.pop();
 844     Node* mem = sfpt->memory();
 845     Node* ctl = sfpt->control();
 846     assert(sfpt->jvms() != NULL, "missed JVMS");
 847     // Fields of scalar objs are referenced only at the end
 848     // of regular debuginfo at the last (youngest) JVMS.
 849     // Record relative start index.
 850     uint first_ind = (sfpt->req() - sfpt->jvms()->scloff());
 851     SafePointScalarObjectNode* sobj = new SafePointScalarObjectNode(res_type,
 852 #ifdef ASSERT
 853                                                  alloc,
 854 #endif
 855                                                  first_ind, nfields);
 856     sobj->init_req(0, C->root());
 857     transform_later(sobj);
 858 
 859     // Scan object's fields adding an input to the safepoint for each field.
 860     for (int j = 0; j < nfields; j++) {
 861       intptr_t offset;
 862       ciField* field = NULL;
 863       if (iklass != NULL) {
 864         field = iklass->nonstatic_field_at(j);
 865         offset = field->offset();
 866         elem_type = field->type();
 867         basic_elem_type = field->layout_type();
 868       } else {
 869         offset = array_base + j * (intptr_t)element_size;
 870       }
 871 
 872       const Type *field_type;
 873       // The next code is taken from Parse::do_get_xxx().
 874       if (basic_elem_type == T_OBJECT || basic_elem_type == T_ARRAY) {
 875         if (!elem_type->is_loaded()) {
 876           field_type = TypeInstPtr::BOTTOM;
 877         } else if (field != NULL && field->is_static_constant()) {
 878           // This can happen if the constant oop is non-perm.
 879           ciObject* con = field->constant_value().as_object();
 880           // Do not "join" in the previous type; it doesn't add value,
 881           // and may yield a vacuous result if the field is of interface type.
 882           field_type = TypeOopPtr::make_from_constant(con)->isa_oopptr();
 883           assert(field_type != NULL, "field singleton type must be consistent");
 884         } else {
 885           field_type = TypeOopPtr::make_from_klass(elem_type->as_klass());
 886         }
 887         if (UseCompressedOops) {
 888           field_type = field_type->make_narrowoop();
 889           basic_elem_type = T_NARROWOOP;
 890         }
 891       } else {
 892         field_type = Type::get_const_basic_type(basic_elem_type);
 893       }
 894 
 895       const TypeOopPtr *field_addr_type = res_type->add_offset(offset)->isa_oopptr();
 896 
 897       Node *field_val = value_from_mem(mem, ctl, basic_elem_type, field_type, field_addr_type, alloc);
 898       if (field_val == NULL) {
 899         // We weren't able to find a value for this field,
 900         // give up on eliminating this allocation.
 901 
 902         // Remove any extra entries we added to the safepoint.
 903         uint last = sfpt->req() - 1;
 904         for (int k = 0;  k < j; k++) {
 905           sfpt->del_req(last--);
 906         }
 907         _igvn._worklist.push(sfpt);
 908         // rollback processed safepoints
 909         while (safepoints_done.length() > 0) {
 910           SafePointNode* sfpt_done = safepoints_done.pop();
 911           // remove any extra entries we added to the safepoint
 912           last = sfpt_done->req() - 1;
 913           for (int k = 0;  k < nfields; k++) {
 914             sfpt_done->del_req(last--);
 915           }
 916           JVMState *jvms = sfpt_done->jvms();
 917           jvms->set_endoff(sfpt_done->req());
 918           // Now make a pass over the debug information replacing any references
 919           // to SafePointScalarObjectNode with the allocated object.
 920           int start = jvms->debug_start();
 921           int end   = jvms->debug_end();
 922           for (int i = start; i < end; i++) {
 923             if (sfpt_done->in(i)->is_SafePointScalarObject()) {
 924               SafePointScalarObjectNode* scobj = sfpt_done->in(i)->as_SafePointScalarObject();
 925               if (scobj->first_index(jvms) == sfpt_done->req() &&
 926                   scobj->n_fields() == (uint)nfields) {
 927                 assert(scobj->alloc() == alloc, "sanity");
 928                 sfpt_done->set_req(i, res);
 929               }
 930             }
 931           }
 932           _igvn._worklist.push(sfpt_done);
 933         }
 934 #ifndef PRODUCT
 935         if (PrintEliminateAllocations) {
 936           if (field != NULL) {
 937             tty->print("=== At SafePoint node %d can't find value of Field: ",
 938                        sfpt->_idx);
 939             field->print();
 940             int field_idx = C->get_alias_index(field_addr_type);
 941             tty->print(" (alias_idx=%d)", field_idx);
 942           } else { // Array's element
 943             tty->print("=== At SafePoint node %d can't find value of array element [%d]",
 944                        sfpt->_idx, j);
 945           }
 946           tty->print(", which prevents elimination of: ");
 947           if (res == NULL)
 948             alloc->dump();
 949           else
 950             res->dump();
 951         }
 952 #endif
 953         return false;
 954       }
 955       if (UseCompressedOops && field_type->isa_narrowoop()) {
 956         // Enable "DecodeN(EncodeP(Allocate)) --> Allocate" transformation
 957         // to be able scalar replace the allocation.
 958         if (field_val->is_EncodeP()) {
 959           field_val = field_val->in(1);
 960         } else {
 961           field_val = transform_later(new DecodeNNode(field_val, field_val->get_ptr_type()));
 962         }
 963       }
 964       sfpt->add_req(field_val);
 965     }
 966     JVMState *jvms = sfpt->jvms();
 967     jvms->set_endoff(sfpt->req());
 968     // Now make a pass over the debug information replacing any references
 969     // to the allocated object with "sobj"
 970     int start = jvms->debug_start();
 971     int end   = jvms->debug_end();
 972     sfpt->replace_edges_in_range(res, sobj, start, end);
 973     _igvn._worklist.push(sfpt);
 974     safepoints_done.append_if_missing(sfpt); // keep it for rollback
 975   }
 976   return true;
 977 }
 978 
 979 static void disconnect_projections(MultiNode* n, PhaseIterGVN& igvn) {
 980   Node* ctl_proj = n->proj_out_or_null(TypeFunc::Control);
 981   Node* mem_proj = n->proj_out_or_null(TypeFunc::Memory);
 982   if (ctl_proj != NULL) {
 983     igvn.replace_node(ctl_proj, n->in(0));
 984   }
 985   if (mem_proj != NULL) {
 986     igvn.replace_node(mem_proj, n->in(TypeFunc::Memory));
 987   }
 988 }
 989 
 990 // Process users of eliminated allocation.
 991 void PhaseMacroExpand::process_users_of_allocation(CallNode *alloc) {
 992   Node* res = alloc->result_cast();
 993   if (res != NULL) {
 994     for (DUIterator_Last jmin, j = res->last_outs(jmin); j >= jmin; ) {
 995       Node *use = res->last_out(j);
 996       uint oc1 = res->outcnt();
 997 
 998       if (use->is_AddP()) {
 999         for (DUIterator_Last kmin, k = use->last_outs(kmin); k >= kmin; ) {
1000           Node *n = use->last_out(k);
1001           uint oc2 = use->outcnt();
1002           if (n->is_Store()) {
1003 #ifdef ASSERT
1004             // Verify that there is no dependent MemBarVolatile nodes,
1005             // they should be removed during IGVN, see MemBarNode::Ideal().
1006             for (DUIterator_Fast pmax, p = n->fast_outs(pmax);
1007                                        p < pmax; p++) {
1008               Node* mb = n->fast_out(p);
1009               assert(mb->is_Initialize() || !mb->is_MemBar() ||
1010                      mb->req() <= MemBarNode::Precedent ||
1011                      mb->in(MemBarNode::Precedent) != n,
1012                      "MemBarVolatile should be eliminated for non-escaping object");
1013             }
1014 #endif
1015             _igvn.replace_node(n, n->in(MemNode::Memory));
1016           } else if (n->is_ArrayCopy()) {
1017             // Disconnect ArrayCopy node
1018             ArrayCopyNode* ac = n->as_ArrayCopy();
1019             assert(ac->is_clonebasic(), "unexpected array copy kind");
1020             Node* membar_after = ac->proj_out(TypeFunc::Control)->unique_ctrl_out();
1021             disconnect_projections(ac, _igvn);
1022             assert(alloc->in(0)->is_Proj() && alloc->in(0)->in(0)->Opcode() == Op_MemBarCPUOrder, "mem barrier expected before allocation");
1023             Node* membar_before = alloc->in(0)->in(0);
1024             disconnect_projections(membar_before->as_MemBar(), _igvn);
1025             if (membar_after->is_MemBar()) {
1026               disconnect_projections(membar_after->as_MemBar(), _igvn);
1027             }
1028           } else {
1029             eliminate_card_mark(n);
1030           }
1031           k -= (oc2 - use->outcnt());
1032         }
1033       } else if (use->is_ArrayCopy()) {
1034         // Disconnect ArrayCopy node
1035         ArrayCopyNode* ac = use->as_ArrayCopy();
1036         assert(ac->is_arraycopy_validated() ||
1037                ac->is_copyof_validated() ||
1038                ac->is_copyofrange_validated(), "unsupported");
1039         CallProjections callprojs;
1040         ac->extract_projections(&callprojs, true);
1041 
1042         _igvn.replace_node(callprojs.fallthrough_ioproj, ac->in(TypeFunc::I_O));
1043         _igvn.replace_node(callprojs.fallthrough_memproj, ac->in(TypeFunc::Memory));
1044         _igvn.replace_node(callprojs.fallthrough_catchproj, ac->in(TypeFunc::Control));
1045 
1046         // Set control to top. IGVN will remove the remaining projections
1047         ac->set_req(0, top());
1048         ac->replace_edge(res, top());
1049 
1050         // Disconnect src right away: it can help find new
1051         // opportunities for allocation elimination
1052         Node* src = ac->in(ArrayCopyNode::Src);
1053         ac->replace_edge(src, top());
1054         // src can be top at this point if src and dest of the
1055         // arraycopy were the same
1056         if (src->outcnt() == 0 && !src->is_top()) {
1057           _igvn.remove_dead_node(src);
1058         }
1059 
1060         _igvn._worklist.push(ac);
1061       } else {
1062         eliminate_card_mark(use);
1063       }
1064       j -= (oc1 - res->outcnt());
1065     }
1066     assert(res->outcnt() == 0, "all uses of allocated objects must be deleted");
1067     _igvn.remove_dead_node(res);
1068   }
1069 
1070   //
1071   // Process other users of allocation's projections
1072   //
1073   if (_resproj != NULL && _resproj->outcnt() != 0) {
1074     // First disconnect stores captured by Initialize node.
1075     // If Initialize node is eliminated first in the following code,
1076     // it will kill such stores and DUIterator_Last will assert.
1077     for (DUIterator_Fast jmax, j = _resproj->fast_outs(jmax);  j < jmax; j++) {
1078       Node *use = _resproj->fast_out(j);
1079       if (use->is_AddP()) {
1080         // raw memory addresses used only by the initialization
1081         _igvn.replace_node(use, C->top());
1082         --j; --jmax;
1083       }
1084     }
1085     for (DUIterator_Last jmin, j = _resproj->last_outs(jmin); j >= jmin; ) {
1086       Node *use = _resproj->last_out(j);
1087       uint oc1 = _resproj->outcnt();
1088       if (use->is_Initialize()) {
1089         // Eliminate Initialize node.
1090         InitializeNode *init = use->as_Initialize();
1091         assert(init->outcnt() <= 2, "only a control and memory projection expected");
1092         Node *ctrl_proj = init->proj_out_or_null(TypeFunc::Control);
1093         if (ctrl_proj != NULL) {
1094            assert(init->in(TypeFunc::Control) == _fallthroughcatchproj, "allocation control projection");
1095           _igvn.replace_node(ctrl_proj, _fallthroughcatchproj);
1096         }
1097         Node *mem_proj = init->proj_out_or_null(TypeFunc::Memory);
1098         if (mem_proj != NULL) {
1099           Node *mem = init->in(TypeFunc::Memory);
1100 #ifdef ASSERT
1101           if (mem->is_MergeMem()) {
1102             assert(mem->in(TypeFunc::Memory) == _memproj_fallthrough, "allocation memory projection");
1103           } else {
1104             assert(mem == _memproj_fallthrough, "allocation memory projection");
1105           }
1106 #endif
1107           _igvn.replace_node(mem_proj, mem);
1108         }
1109       } else  {
1110         assert(false, "only Initialize or AddP expected");
1111       }
1112       j -= (oc1 - _resproj->outcnt());
1113     }
1114   }
1115   if (_fallthroughcatchproj != NULL) {
1116     _igvn.replace_node(_fallthroughcatchproj, alloc->in(TypeFunc::Control));
1117   }
1118   if (_memproj_fallthrough != NULL) {
1119     _igvn.replace_node(_memproj_fallthrough, alloc->in(TypeFunc::Memory));
1120   }
1121   if (_memproj_catchall != NULL) {
1122     _igvn.replace_node(_memproj_catchall, C->top());
1123   }
1124   if (_ioproj_fallthrough != NULL) {
1125     _igvn.replace_node(_ioproj_fallthrough, alloc->in(TypeFunc::I_O));
1126   }
1127   if (_ioproj_catchall != NULL) {
1128     _igvn.replace_node(_ioproj_catchall, C->top());
1129   }
1130   if (_catchallcatchproj != NULL) {
1131     _igvn.replace_node(_catchallcatchproj, C->top());
1132   }
1133 }
1134 
1135 bool PhaseMacroExpand::eliminate_allocate_node(AllocateNode *alloc) {
1136   // Don't do scalar replacement if the frame can be popped by JVMTI:
1137   // if reallocation fails during deoptimization we'll pop all
1138   // interpreter frames for this compiled frame and that won't play
1139   // nice with JVMTI popframe.
1140   if (!EliminateAllocations || JvmtiExport::can_pop_frame() || !alloc->_is_non_escaping) {
1141     return false;
1142   }
1143   Node* klass = alloc->in(AllocateNode::KlassNode);
1144   const TypeKlassPtr* tklass = _igvn.type(klass)->is_klassptr();
1145   Node* res = alloc->result_cast();
1146   // Eliminate boxing allocations which are not used
1147   // regardless scalar replacable status.
1148   bool boxing_alloc = C->eliminate_boxing() &&
1149                       tklass->klass()->is_instance_klass()  &&
1150                       tklass->klass()->as_instance_klass()->is_box_klass();
1151   if (!alloc->_is_scalar_replaceable && (!boxing_alloc || (res != NULL))) {
1152     return false;
1153   }
1154 
1155   extract_call_projections(alloc);
1156 
1157   GrowableArray <SafePointNode *> safepoints;
1158   if (!can_eliminate_allocation(alloc, safepoints)) {
1159     return false;
1160   }
1161 
1162   if (!alloc->_is_scalar_replaceable) {
1163     assert(res == NULL, "sanity");
1164     // We can only eliminate allocation if all debug info references
1165     // are already replaced with SafePointScalarObject because
1166     // we can't search for a fields value without instance_id.
1167     if (safepoints.length() > 0) {
1168       return false;
1169     }
1170   }
1171 
1172   if (!scalar_replacement(alloc, safepoints)) {
1173     return false;
1174   }
1175 
1176   CompileLog* log = C->log();
1177   if (log != NULL) {
1178     log->head("eliminate_allocation type='%d'",
1179               log->identify(tklass->klass()));
1180     JVMState* p = alloc->jvms();
1181     while (p != NULL) {
1182       log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
1183       p = p->caller();
1184     }
1185     log->tail("eliminate_allocation");
1186   }
1187 
1188   process_users_of_allocation(alloc);
1189 
1190 #ifndef PRODUCT
1191   if (PrintEliminateAllocations) {
1192     if (alloc->is_AllocateArray())
1193       tty->print_cr("++++ Eliminated: %d AllocateArray", alloc->_idx);
1194     else
1195       tty->print_cr("++++ Eliminated: %d Allocate", alloc->_idx);
1196   }
1197 #endif
1198 
1199   return true;
1200 }
1201 
1202 bool PhaseMacroExpand::eliminate_boxing_node(CallStaticJavaNode *boxing) {
1203   // EA should remove all uses of non-escaping boxing node.
1204   if (!C->eliminate_boxing() || boxing->proj_out_or_null(TypeFunc::Parms) != NULL) {
1205     return false;
1206   }
1207 
1208   assert(boxing->result_cast() == NULL, "unexpected boxing node result");
1209 
1210   extract_call_projections(boxing);
1211 
1212   const TypeTuple* r = boxing->tf()->range();
1213   assert(r->cnt() > TypeFunc::Parms, "sanity");
1214   const TypeInstPtr* t = r->field_at(TypeFunc::Parms)->isa_instptr();
1215   assert(t != NULL, "sanity");
1216 
1217   CompileLog* log = C->log();
1218   if (log != NULL) {
1219     log->head("eliminate_boxing type='%d'",
1220               log->identify(t->klass()));
1221     JVMState* p = boxing->jvms();
1222     while (p != NULL) {
1223       log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
1224       p = p->caller();
1225     }
1226     log->tail("eliminate_boxing");
1227   }
1228 
1229   process_users_of_allocation(boxing);
1230 
1231 #ifndef PRODUCT
1232   if (PrintEliminateAllocations) {
1233     tty->print("++++ Eliminated: %d ", boxing->_idx);
1234     boxing->method()->print_short_name(tty);
1235     tty->cr();
1236   }
1237 #endif
1238 
1239   return true;
1240 }
1241 
1242 //---------------------------set_eden_pointers-------------------------
1243 void PhaseMacroExpand::set_eden_pointers(Node* &eden_top_adr, Node* &eden_end_adr) {
1244   if (UseTLAB) {                // Private allocation: load from TLS
1245     Node* thread = transform_later(new ThreadLocalNode());
1246     int tlab_top_offset = in_bytes(JavaThread::tlab_top_offset());
1247     int tlab_end_offset = in_bytes(JavaThread::tlab_end_offset());
1248     eden_top_adr = basic_plus_adr(top()/*not oop*/, thread, tlab_top_offset);
1249     eden_end_adr = basic_plus_adr(top()/*not oop*/, thread, tlab_end_offset);
1250   } else {                      // Shared allocation: load from globals
1251     CollectedHeap* ch = Universe::heap();
1252     address top_adr = (address)ch->top_addr();
1253     address end_adr = (address)ch->end_addr();
1254     eden_top_adr = makecon(TypeRawPtr::make(top_adr));
1255     eden_end_adr = basic_plus_adr(eden_top_adr, end_adr - top_adr);
1256   }
1257 }
1258 
1259 
1260 Node* PhaseMacroExpand::make_load(Node* ctl, Node* mem, Node* base, int offset, const Type* value_type, BasicType bt) {
1261   Node* adr = basic_plus_adr(base, offset);
1262   const TypePtr* adr_type = adr->bottom_type()->is_ptr();
1263   Node* value = LoadNode::make(_igvn, ctl, mem, adr, adr_type, value_type, bt, MemNode::unordered);
1264   transform_later(value);
1265   return value;
1266 }
1267 
1268 
1269 Node* PhaseMacroExpand::make_store(Node* ctl, Node* mem, Node* base, int offset, Node* value, BasicType bt) {
1270   Node* adr = basic_plus_adr(base, offset);
1271   mem = StoreNode::make(_igvn, ctl, mem, adr, NULL, value, bt, MemNode::unordered);
1272   transform_later(mem);
1273   return mem;
1274 }
1275 
1276 //=============================================================================
1277 //
1278 //                              A L L O C A T I O N
1279 //
1280 // Allocation attempts to be fast in the case of frequent small objects.
1281 // It breaks down like this:
1282 //
1283 // 1) Size in doublewords is computed.  This is a constant for objects and
1284 // variable for most arrays.  Doubleword units are used to avoid size
1285 // overflow of huge doubleword arrays.  We need doublewords in the end for
1286 // rounding.
1287 //
1288 // 2) Size is checked for being 'too large'.  Too-large allocations will go
1289 // the slow path into the VM.  The slow path can throw any required
1290 // exceptions, and does all the special checks for very large arrays.  The
1291 // size test can constant-fold away for objects.  For objects with
1292 // finalizers it constant-folds the otherway: you always go slow with
1293 // finalizers.
1294 //
1295 // 3) If NOT using TLABs, this is the contended loop-back point.
1296 // Load-Locked the heap top.  If using TLABs normal-load the heap top.
1297 //
1298 // 4) Check that heap top + size*8 < max.  If we fail go the slow ` route.
1299 // NOTE: "top+size*8" cannot wrap the 4Gig line!  Here's why: for largish
1300 // "size*8" we always enter the VM, where "largish" is a constant picked small
1301 // enough that there's always space between the eden max and 4Gig (old space is
1302 // there so it's quite large) and large enough that the cost of entering the VM
1303 // is dwarfed by the cost to initialize the space.
1304 //
1305 // 5) If NOT using TLABs, Store-Conditional the adjusted heap top back
1306 // down.  If contended, repeat at step 3.  If using TLABs normal-store
1307 // adjusted heap top back down; there is no contention.
1308 //
1309 // 6) If !ZeroTLAB then Bulk-clear the object/array.  Fill in klass & mark
1310 // fields.
1311 //
1312 // 7) Merge with the slow-path; cast the raw memory pointer to the correct
1313 // oop flavor.
1314 //
1315 //=============================================================================
1316 // FastAllocateSizeLimit value is in DOUBLEWORDS.
1317 // Allocations bigger than this always go the slow route.
1318 // This value must be small enough that allocation attempts that need to
1319 // trigger exceptions go the slow route.  Also, it must be small enough so
1320 // that heap_top + size_in_bytes does not wrap around the 4Gig limit.
1321 //=============================================================================j//
1322 // %%% Here is an old comment from parseHelper.cpp; is it outdated?
1323 // The allocator will coalesce int->oop copies away.  See comment in
1324 // coalesce.cpp about how this works.  It depends critically on the exact
1325 // code shape produced here, so if you are changing this code shape
1326 // make sure the GC info for the heap-top is correct in and around the
1327 // slow-path call.
1328 //
1329 
1330 void PhaseMacroExpand::expand_allocate_common(
1331             AllocateNode* alloc, // allocation node to be expanded
1332             Node* length,  // array length for an array allocation
1333             const TypeFunc* slow_call_type, // Type of slow call
1334             address slow_call_address  // Address of slow call
1335     )
1336 {
1337 
1338   Node* ctrl = alloc->in(TypeFunc::Control);
1339   Node* mem  = alloc->in(TypeFunc::Memory);
1340   Node* i_o  = alloc->in(TypeFunc::I_O);
1341   Node* size_in_bytes     = alloc->in(AllocateNode::AllocSize);
1342   Node* klass_node        = alloc->in(AllocateNode::KlassNode);
1343   Node* initial_slow_test = alloc->in(AllocateNode::InitialTest);
1344 
1345   assert(ctrl != NULL, "must have control");
1346   // We need a Region and corresponding Phi's to merge the slow-path and fast-path results.
1347   // they will not be used if "always_slow" is set
1348   enum { slow_result_path = 1, fast_result_path = 2 };
1349   Node *result_region = NULL;
1350   Node *result_phi_rawmem = NULL;
1351   Node *result_phi_rawoop = NULL;
1352   Node *result_phi_i_o = NULL;
1353 
1354   // The initial slow comparison is a size check, the comparison
1355   // we want to do is a BoolTest::gt
1356   bool always_slow = false;
1357   int tv = _igvn.find_int_con(initial_slow_test, -1);
1358   if (tv >= 0) {
1359     always_slow = (tv == 1);
1360     initial_slow_test = NULL;
1361   } else {
1362     initial_slow_test = BoolNode::make_predicate(initial_slow_test, &_igvn);
1363   }
1364 
1365   if (C->env()->dtrace_alloc_probes() ||
1366       (!UseTLAB && !Universe::heap()->supports_inline_contig_alloc())) {
1367     // Force slow-path allocation
1368     always_slow = true;
1369     initial_slow_test = NULL;
1370   }
1371 
1372 
1373   enum { too_big_or_final_path = 1, need_gc_path = 2 };
1374   Node *slow_region = NULL;
1375   Node *toobig_false = ctrl;
1376 
1377   assert (initial_slow_test == NULL || !always_slow, "arguments must be consistent");
1378   // generate the initial test if necessary
1379   if (initial_slow_test != NULL ) {
1380     slow_region = new RegionNode(3);
1381 
1382     // Now make the initial failure test.  Usually a too-big test but
1383     // might be a TRUE for finalizers or a fancy class check for
1384     // newInstance0.
1385     IfNode *toobig_iff = new IfNode(ctrl, initial_slow_test, PROB_MIN, COUNT_UNKNOWN);
1386     transform_later(toobig_iff);
1387     // Plug the failing-too-big test into the slow-path region
1388     Node *toobig_true = new IfTrueNode( toobig_iff );
1389     transform_later(toobig_true);
1390     slow_region    ->init_req( too_big_or_final_path, toobig_true );
1391     toobig_false = new IfFalseNode( toobig_iff );
1392     transform_later(toobig_false);
1393   } else {         // No initial test, just fall into next case
1394     toobig_false = ctrl;
1395     debug_only(slow_region = NodeSentinel);
1396   }
1397 
1398   Node *slow_mem = mem;  // save the current memory state for slow path
1399   // generate the fast allocation code unless we know that the initial test will always go slow
1400   if (!always_slow) {
1401     // Fast path modifies only raw memory.
1402     if (mem->is_MergeMem()) {
1403       mem = mem->as_MergeMem()->memory_at(Compile::AliasIdxRaw);
1404     }
1405 
1406     Node* eden_top_adr;
1407     Node* eden_end_adr;
1408 
1409     set_eden_pointers(eden_top_adr, eden_end_adr);
1410 
1411     // Load Eden::end.  Loop invariant and hoisted.
1412     //
1413     // Note: We set the control input on "eden_end" and "old_eden_top" when using
1414     //       a TLAB to work around a bug where these values were being moved across
1415     //       a safepoint.  These are not oops, so they cannot be include in the oop
1416     //       map, but they can be changed by a GC.   The proper way to fix this would
1417     //       be to set the raw memory state when generating a  SafepointNode.  However
1418     //       this will require extensive changes to the loop optimization in order to
1419     //       prevent a degradation of the optimization.
1420     //       See comment in memnode.hpp, around line 227 in class LoadPNode.
1421     Node *eden_end = make_load(ctrl, mem, eden_end_adr, 0, TypeRawPtr::BOTTOM, T_ADDRESS);
1422 
1423     // allocate the Region and Phi nodes for the result
1424     result_region = new RegionNode(3);
1425     result_phi_rawmem = new PhiNode(result_region, Type::MEMORY, TypeRawPtr::BOTTOM);
1426     result_phi_rawoop = new PhiNode(result_region, TypeRawPtr::BOTTOM);
1427     result_phi_i_o    = new PhiNode(result_region, Type::ABIO); // I/O is used for Prefetch
1428 
1429     // We need a Region for the loop-back contended case.
1430     enum { fall_in_path = 1, contended_loopback_path = 2 };
1431     Node *contended_region;
1432     Node *contended_phi_rawmem;
1433     if (UseTLAB) {
1434       contended_region = toobig_false;
1435       contended_phi_rawmem = mem;
1436     } else {
1437       contended_region = new RegionNode(3);
1438       contended_phi_rawmem = new PhiNode(contended_region, Type::MEMORY, TypeRawPtr::BOTTOM);
1439       // Now handle the passing-too-big test.  We fall into the contended
1440       // loop-back merge point.
1441       contended_region    ->init_req(fall_in_path, toobig_false);
1442       contended_phi_rawmem->init_req(fall_in_path, mem);
1443       transform_later(contended_region);
1444       transform_later(contended_phi_rawmem);
1445     }
1446 
1447     // Load(-locked) the heap top.
1448     // See note above concerning the control input when using a TLAB
1449     Node *old_eden_top = UseTLAB
1450       ? new LoadPNode      (ctrl, contended_phi_rawmem, eden_top_adr, TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM, MemNode::unordered)
1451       : new LoadPLockedNode(contended_region, contended_phi_rawmem, eden_top_adr, MemNode::acquire);
1452 
1453     transform_later(old_eden_top);
1454     // Add to heap top to get a new heap top
1455     Node *new_eden_top = new AddPNode(top(), old_eden_top, size_in_bytes);
1456     transform_later(new_eden_top);
1457     // Check for needing a GC; compare against heap end
1458     Node *needgc_cmp = new CmpPNode(new_eden_top, eden_end);
1459     transform_later(needgc_cmp);
1460     Node *needgc_bol = new BoolNode(needgc_cmp, BoolTest::ge);
1461     transform_later(needgc_bol);
1462     IfNode *needgc_iff = new IfNode(contended_region, needgc_bol, PROB_UNLIKELY_MAG(4), COUNT_UNKNOWN);
1463     transform_later(needgc_iff);
1464 
1465     // Plug the failing-heap-space-need-gc test into the slow-path region
1466     Node *needgc_true = new IfTrueNode(needgc_iff);
1467     transform_later(needgc_true);
1468     if (initial_slow_test) {
1469       slow_region->init_req(need_gc_path, needgc_true);
1470       // This completes all paths into the slow merge point
1471       transform_later(slow_region);
1472     } else {                      // No initial slow path needed!
1473       // Just fall from the need-GC path straight into the VM call.
1474       slow_region = needgc_true;
1475     }
1476     // No need for a GC.  Setup for the Store-Conditional
1477     Node *needgc_false = new IfFalseNode(needgc_iff);
1478     transform_later(needgc_false);
1479 
1480     // Grab regular I/O before optional prefetch may change it.
1481     // Slow-path does no I/O so just set it to the original I/O.
1482     result_phi_i_o->init_req(slow_result_path, i_o);
1483 
1484     i_o = prefetch_allocation(i_o, needgc_false, contended_phi_rawmem,
1485                               old_eden_top, new_eden_top, length);
1486 
1487     // Name successful fast-path variables
1488     Node* fast_oop = old_eden_top;
1489     Node* fast_oop_ctrl;
1490     Node* fast_oop_rawmem;
1491 
1492     // Store (-conditional) the modified eden top back down.
1493     // StorePConditional produces flags for a test PLUS a modified raw
1494     // memory state.
1495     if (UseTLAB) {
1496       Node* store_eden_top =
1497         new StorePNode(needgc_false, contended_phi_rawmem, eden_top_adr,
1498                               TypeRawPtr::BOTTOM, new_eden_top, MemNode::unordered);
1499       transform_later(store_eden_top);
1500       fast_oop_ctrl = needgc_false; // No contention, so this is the fast path
1501       fast_oop_rawmem = store_eden_top;
1502     } else {
1503       Node* store_eden_top =
1504         new StorePConditionalNode(needgc_false, contended_phi_rawmem, eden_top_adr,
1505                                          new_eden_top, fast_oop/*old_eden_top*/);
1506       transform_later(store_eden_top);
1507       Node *contention_check = new BoolNode(store_eden_top, BoolTest::ne);
1508       transform_later(contention_check);
1509       store_eden_top = new SCMemProjNode(store_eden_top);
1510       transform_later(store_eden_top);
1511 
1512       // If not using TLABs, check to see if there was contention.
1513       IfNode *contention_iff = new IfNode (needgc_false, contention_check, PROB_MIN, COUNT_UNKNOWN);
1514       transform_later(contention_iff);
1515       Node *contention_true = new IfTrueNode(contention_iff);
1516       transform_later(contention_true);
1517       // If contention, loopback and try again.
1518       contended_region->init_req(contended_loopback_path, contention_true);
1519       contended_phi_rawmem->init_req(contended_loopback_path, store_eden_top);
1520 
1521       // Fast-path succeeded with no contention!
1522       Node *contention_false = new IfFalseNode(contention_iff);
1523       transform_later(contention_false);
1524       fast_oop_ctrl = contention_false;
1525 
1526       // Bump total allocated bytes for this thread
1527       Node* thread = new ThreadLocalNode();
1528       transform_later(thread);
1529       Node* alloc_bytes_adr = basic_plus_adr(top()/*not oop*/, thread,
1530                                              in_bytes(JavaThread::allocated_bytes_offset()));
1531       Node* alloc_bytes = make_load(fast_oop_ctrl, store_eden_top, alloc_bytes_adr,
1532                                     0, TypeLong::LONG, T_LONG);
1533 #ifdef _LP64
1534       Node* alloc_size = size_in_bytes;
1535 #else
1536       Node* alloc_size = new ConvI2LNode(size_in_bytes);
1537       transform_later(alloc_size);
1538 #endif
1539       Node* new_alloc_bytes = new AddLNode(alloc_bytes, alloc_size);
1540       transform_later(new_alloc_bytes);
1541       fast_oop_rawmem = make_store(fast_oop_ctrl, store_eden_top, alloc_bytes_adr,
1542                                    0, new_alloc_bytes, T_LONG);
1543     }
1544 
1545     InitializeNode* init = alloc->initialization();
1546     fast_oop_rawmem = initialize_object(alloc,
1547                                         fast_oop_ctrl, fast_oop_rawmem, fast_oop,
1548                                         klass_node, length, size_in_bytes);
1549 
1550     // If initialization is performed by an array copy, any required
1551     // MemBarStoreStore was already added. If the object does not
1552     // escape no need for a MemBarStoreStore. If the object does not
1553     // escape in its initializer and memory barrier (MemBarStoreStore or
1554     // stronger) is already added at exit of initializer, also no need
1555     // for a MemBarStoreStore. Otherwise we need a MemBarStoreStore
1556     // so that stores that initialize this object can't be reordered
1557     // with a subsequent store that makes this object accessible by
1558     // other threads.
1559     // Other threads include java threads and JVM internal threads
1560     // (for example concurrent GC threads). Current concurrent GC
1561     // implementation: CMS and G1 will not scan newly created object,
1562     // so it's safe to skip storestore barrier when allocation does
1563     // not escape.
1564     if (!alloc->does_not_escape_thread() &&
1565         !alloc->is_allocation_MemBar_redundant() &&
1566         (init == NULL || !init->is_complete_with_arraycopy())) {
1567       if (init == NULL || init->req() < InitializeNode::RawStores) {
1568         // No InitializeNode or no stores captured by zeroing
1569         // elimination. Simply add the MemBarStoreStore after object
1570         // initialization.
1571         MemBarNode* mb = MemBarNode::make(C, Op_MemBarStoreStore, Compile::AliasIdxBot);
1572         transform_later(mb);
1573 
1574         mb->init_req(TypeFunc::Memory, fast_oop_rawmem);
1575         mb->init_req(TypeFunc::Control, fast_oop_ctrl);
1576         fast_oop_ctrl = new ProjNode(mb,TypeFunc::Control);
1577         transform_later(fast_oop_ctrl);
1578         fast_oop_rawmem = new ProjNode(mb,TypeFunc::Memory);
1579         transform_later(fast_oop_rawmem);
1580       } else {
1581         // Add the MemBarStoreStore after the InitializeNode so that
1582         // all stores performing the initialization that were moved
1583         // before the InitializeNode happen before the storestore
1584         // barrier.
1585 
1586         Node* init_ctrl = init->proj_out_or_null(TypeFunc::Control);
1587         Node* init_mem = init->proj_out_or_null(TypeFunc::Memory);
1588 
1589         MemBarNode* mb = MemBarNode::make(C, Op_MemBarStoreStore, Compile::AliasIdxBot);
1590         transform_later(mb);
1591 
1592         Node* ctrl = new ProjNode(init,TypeFunc::Control);
1593         transform_later(ctrl);
1594         Node* mem = new ProjNode(init,TypeFunc::Memory);
1595         transform_later(mem);
1596 
1597         // The MemBarStoreStore depends on control and memory coming
1598         // from the InitializeNode
1599         mb->init_req(TypeFunc::Memory, mem);
1600         mb->init_req(TypeFunc::Control, ctrl);
1601 
1602         ctrl = new ProjNode(mb,TypeFunc::Control);
1603         transform_later(ctrl);
1604         mem = new ProjNode(mb,TypeFunc::Memory);
1605         transform_later(mem);
1606 
1607         // All nodes that depended on the InitializeNode for control
1608         // and memory must now depend on the MemBarNode that itself
1609         // depends on the InitializeNode
1610         if (init_ctrl != NULL) {
1611           _igvn.replace_node(init_ctrl, ctrl);
1612         }
1613         if (init_mem != NULL) {
1614           _igvn.replace_node(init_mem, mem);
1615         }
1616       }
1617     }
1618 
1619     if (C->env()->dtrace_extended_probes()) {
1620       // Slow-path call
1621       int size = TypeFunc::Parms + 2;
1622       CallLeafNode *call = new CallLeafNode(OptoRuntime::dtrace_object_alloc_Type(),
1623                                             CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_object_alloc_base),
1624                                             "dtrace_object_alloc",
1625                                             TypeRawPtr::BOTTOM);
1626 
1627       // Get base of thread-local storage area
1628       Node* thread = new ThreadLocalNode();
1629       transform_later(thread);
1630 
1631       call->init_req(TypeFunc::Parms+0, thread);
1632       call->init_req(TypeFunc::Parms+1, fast_oop);
1633       call->init_req(TypeFunc::Control, fast_oop_ctrl);
1634       call->init_req(TypeFunc::I_O    , top()); // does no i/o
1635       call->init_req(TypeFunc::Memory , fast_oop_rawmem);
1636       call->init_req(TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr));
1637       call->init_req(TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr));
1638       transform_later(call);
1639       fast_oop_ctrl = new ProjNode(call,TypeFunc::Control);
1640       transform_later(fast_oop_ctrl);
1641       fast_oop_rawmem = new ProjNode(call,TypeFunc::Memory);
1642       transform_later(fast_oop_rawmem);
1643     }
1644 
1645     // Plug in the successful fast-path into the result merge point
1646     result_region    ->init_req(fast_result_path, fast_oop_ctrl);
1647     result_phi_rawoop->init_req(fast_result_path, fast_oop);
1648     result_phi_i_o   ->init_req(fast_result_path, i_o);
1649     result_phi_rawmem->init_req(fast_result_path, fast_oop_rawmem);
1650   } else {
1651     slow_region = ctrl;
1652     result_phi_i_o = i_o; // Rename it to use in the following code.
1653   }
1654 
1655   // Generate slow-path call
1656   CallNode *call = new CallStaticJavaNode(slow_call_type, slow_call_address,
1657                                OptoRuntime::stub_name(slow_call_address),
1658                                alloc->jvms()->bci(),
1659                                TypePtr::BOTTOM);
1660   call->init_req( TypeFunc::Control, slow_region );
1661   call->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
1662   call->init_req( TypeFunc::Memory , slow_mem ); // may gc ptrs
1663   call->init_req( TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr) );
1664   call->init_req( TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr) );
1665 
1666   call->init_req(TypeFunc::Parms+0, klass_node);
1667   if (length != NULL) {
1668     call->init_req(TypeFunc::Parms+1, length);
1669   }
1670 
1671   // Copy debug information and adjust JVMState information, then replace
1672   // allocate node with the call
1673   copy_call_debug_info((CallNode *) alloc,  call);
1674   if (!always_slow) {
1675     call->set_cnt(PROB_UNLIKELY_MAG(4));  // Same effect as RC_UNCOMMON.
1676   } else {
1677     // Hook i_o projection to avoid its elimination during allocation
1678     // replacement (when only a slow call is generated).
1679     call->set_req(TypeFunc::I_O, result_phi_i_o);
1680   }
1681   _igvn.replace_node(alloc, call);
1682   transform_later(call);
1683 
1684   // Identify the output projections from the allocate node and
1685   // adjust any references to them.
1686   // The control and io projections look like:
1687   //
1688   //        v---Proj(ctrl) <-----+   v---CatchProj(ctrl)
1689   //  Allocate                   Catch
1690   //        ^---Proj(io) <-------+   ^---CatchProj(io)
1691   //
1692   //  We are interested in the CatchProj nodes.
1693   //
1694   extract_call_projections(call);
1695 
1696   // An allocate node has separate memory projections for the uses on
1697   // the control and i_o paths. Replace the control memory projection with
1698   // result_phi_rawmem (unless we are only generating a slow call when
1699   // both memory projections are combined)
1700   if (!always_slow && _memproj_fallthrough != NULL) {
1701     for (DUIterator_Fast imax, i = _memproj_fallthrough->fast_outs(imax); i < imax; i++) {
1702       Node *use = _memproj_fallthrough->fast_out(i);
1703       _igvn.rehash_node_delayed(use);
1704       imax -= replace_input(use, _memproj_fallthrough, result_phi_rawmem);
1705       // back up iterator
1706       --i;
1707     }
1708   }
1709   // Now change uses of _memproj_catchall to use _memproj_fallthrough and delete
1710   // _memproj_catchall so we end up with a call that has only 1 memory projection.
1711   if (_memproj_catchall != NULL ) {
1712     if (_memproj_fallthrough == NULL) {
1713       _memproj_fallthrough = new ProjNode(call, TypeFunc::Memory);
1714       transform_later(_memproj_fallthrough);
1715     }
1716     for (DUIterator_Fast imax, i = _memproj_catchall->fast_outs(imax); i < imax; i++) {
1717       Node *use = _memproj_catchall->fast_out(i);
1718       _igvn.rehash_node_delayed(use);
1719       imax -= replace_input(use, _memproj_catchall, _memproj_fallthrough);
1720       // back up iterator
1721       --i;
1722     }
1723     assert(_memproj_catchall->outcnt() == 0, "all uses must be deleted");
1724     _igvn.remove_dead_node(_memproj_catchall);
1725   }
1726 
1727   // An allocate node has separate i_o projections for the uses on the control
1728   // and i_o paths. Always replace the control i_o projection with result i_o
1729   // otherwise incoming i_o become dead when only a slow call is generated
1730   // (it is different from memory projections where both projections are
1731   // combined in such case).
1732   if (_ioproj_fallthrough != NULL) {
1733     for (DUIterator_Fast imax, i = _ioproj_fallthrough->fast_outs(imax); i < imax; i++) {
1734       Node *use = _ioproj_fallthrough->fast_out(i);
1735       _igvn.rehash_node_delayed(use);
1736       imax -= replace_input(use, _ioproj_fallthrough, result_phi_i_o);
1737       // back up iterator
1738       --i;
1739     }
1740   }
1741   // Now change uses of _ioproj_catchall to use _ioproj_fallthrough and delete
1742   // _ioproj_catchall so we end up with a call that has only 1 i_o projection.
1743   if (_ioproj_catchall != NULL ) {
1744     if (_ioproj_fallthrough == NULL) {
1745       _ioproj_fallthrough = new ProjNode(call, TypeFunc::I_O);
1746       transform_later(_ioproj_fallthrough);
1747     }
1748     for (DUIterator_Fast imax, i = _ioproj_catchall->fast_outs(imax); i < imax; i++) {
1749       Node *use = _ioproj_catchall->fast_out(i);
1750       _igvn.rehash_node_delayed(use);
1751       imax -= replace_input(use, _ioproj_catchall, _ioproj_fallthrough);
1752       // back up iterator
1753       --i;
1754     }
1755     assert(_ioproj_catchall->outcnt() == 0, "all uses must be deleted");
1756     _igvn.remove_dead_node(_ioproj_catchall);
1757   }
1758 
1759   // if we generated only a slow call, we are done
1760   if (always_slow) {
1761     // Now we can unhook i_o.
1762     if (result_phi_i_o->outcnt() > 1) {
1763       call->set_req(TypeFunc::I_O, top());
1764     } else {
1765       assert(result_phi_i_o->unique_ctrl_out() == call, "");
1766       // Case of new array with negative size known during compilation.
1767       // AllocateArrayNode::Ideal() optimization disconnect unreachable
1768       // following code since call to runtime will throw exception.
1769       // As result there will be no users of i_o after the call.
1770       // Leave i_o attached to this call to avoid problems in preceding graph.
1771     }
1772     return;
1773   }
1774 
1775 
1776   if (_fallthroughcatchproj != NULL) {
1777     ctrl = _fallthroughcatchproj->clone();
1778     transform_later(ctrl);
1779     _igvn.replace_node(_fallthroughcatchproj, result_region);
1780   } else {
1781     ctrl = top();
1782   }
1783   Node *slow_result;
1784   if (_resproj == NULL) {
1785     // no uses of the allocation result
1786     slow_result = top();
1787   } else {
1788     slow_result = _resproj->clone();
1789     transform_later(slow_result);
1790     _igvn.replace_node(_resproj, result_phi_rawoop);
1791   }
1792 
1793   // Plug slow-path into result merge point
1794   result_region    ->init_req( slow_result_path, ctrl );
1795   result_phi_rawoop->init_req( slow_result_path, slow_result);
1796   result_phi_rawmem->init_req( slow_result_path, _memproj_fallthrough );
1797   transform_later(result_region);
1798   transform_later(result_phi_rawoop);
1799   transform_later(result_phi_rawmem);
1800   transform_later(result_phi_i_o);
1801   // This completes all paths into the result merge point
1802 }
1803 
1804 
1805 // Helper for PhaseMacroExpand::expand_allocate_common.
1806 // Initializes the newly-allocated storage.
1807 Node*
1808 PhaseMacroExpand::initialize_object(AllocateNode* alloc,
1809                                     Node* control, Node* rawmem, Node* object,
1810                                     Node* klass_node, Node* length,
1811                                     Node* size_in_bytes) {
1812   InitializeNode* init = alloc->initialization();
1813   // Store the klass & mark bits
1814   Node* mark_node = NULL;
1815   // For now only enable fast locking for non-array types
1816   if (UseBiasedLocking && (length == NULL)) {
1817     mark_node = make_load(control, rawmem, klass_node, in_bytes(Klass::prototype_header_offset()), TypeRawPtr::BOTTOM, T_ADDRESS);
1818   } else {
1819     mark_node = makecon(TypeRawPtr::make((address)markOopDesc::prototype()));
1820   }
1821   rawmem = make_store(control, rawmem, object, oopDesc::mark_offset_in_bytes(), mark_node, T_ADDRESS);
1822 
1823   rawmem = make_store(control, rawmem, object, oopDesc::klass_offset_in_bytes(), klass_node, T_METADATA);
1824   int header_size = alloc->minimum_header_size();  // conservatively small
1825 
1826   // Array length
1827   if (length != NULL) {         // Arrays need length field
1828     rawmem = make_store(control, rawmem, object, arrayOopDesc::length_offset_in_bytes(), length, T_INT);
1829     // conservatively small header size:
1830     header_size = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1831     ciKlass* k = _igvn.type(klass_node)->is_klassptr()->klass();
1832     if (k->is_array_klass())    // we know the exact header size in most cases:
1833       header_size = Klass::layout_helper_header_size(k->layout_helper());
1834   }
1835 
1836   // Clear the object body, if necessary.
1837   if (init == NULL) {
1838     // The init has somehow disappeared; be cautious and clear everything.
1839     //
1840     // This can happen if a node is allocated but an uncommon trap occurs
1841     // immediately.  In this case, the Initialize gets associated with the
1842     // trap, and may be placed in a different (outer) loop, if the Allocate
1843     // is in a loop.  If (this is rare) the inner loop gets unrolled, then
1844     // there can be two Allocates to one Initialize.  The answer in all these
1845     // edge cases is safety first.  It is always safe to clear immediately
1846     // within an Allocate, and then (maybe or maybe not) clear some more later.
1847     if (!(UseTLAB && ZeroTLAB)) {
1848       rawmem = ClearArrayNode::clear_memory(control, rawmem, object,
1849                                             header_size, size_in_bytes,
1850                                             &_igvn);
1851     }
1852   } else {
1853     if (!init->is_complete()) {
1854       // Try to win by zeroing only what the init does not store.
1855       // We can also try to do some peephole optimizations,
1856       // such as combining some adjacent subword stores.
1857       rawmem = init->complete_stores(control, rawmem, object,
1858                                      header_size, size_in_bytes, &_igvn);
1859     }
1860     // We have no more use for this link, since the AllocateNode goes away:
1861     init->set_req(InitializeNode::RawAddress, top());
1862     // (If we keep the link, it just confuses the register allocator,
1863     // who thinks he sees a real use of the address by the membar.)
1864   }
1865 
1866   return rawmem;
1867 }
1868 
1869 // Generate prefetch instructions for next allocations.
1870 Node* PhaseMacroExpand::prefetch_allocation(Node* i_o, Node*& needgc_false,
1871                                         Node*& contended_phi_rawmem,
1872                                         Node* old_eden_top, Node* new_eden_top,
1873                                         Node* length) {
1874    enum { fall_in_path = 1, pf_path = 2 };
1875    if( UseTLAB && AllocatePrefetchStyle == 2 ) {
1876       // Generate prefetch allocation with watermark check.
1877       // As an allocation hits the watermark, we will prefetch starting
1878       // at a "distance" away from watermark.
1879 
1880       Node *pf_region = new RegionNode(3);
1881       Node *pf_phi_rawmem = new PhiNode( pf_region, Type::MEMORY,
1882                                                 TypeRawPtr::BOTTOM );
1883       // I/O is used for Prefetch
1884       Node *pf_phi_abio = new PhiNode( pf_region, Type::ABIO );
1885 
1886       Node *thread = new ThreadLocalNode();
1887       transform_later(thread);
1888 
1889       Node *eden_pf_adr = new AddPNode( top()/*not oop*/, thread,
1890                    _igvn.MakeConX(in_bytes(JavaThread::tlab_pf_top_offset())) );
1891       transform_later(eden_pf_adr);
1892 
1893       Node *old_pf_wm = new LoadPNode(needgc_false,
1894                                    contended_phi_rawmem, eden_pf_adr,
1895                                    TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM,
1896                                    MemNode::unordered);
1897       transform_later(old_pf_wm);
1898 
1899       // check against new_eden_top
1900       Node *need_pf_cmp = new CmpPNode( new_eden_top, old_pf_wm );
1901       transform_later(need_pf_cmp);
1902       Node *need_pf_bol = new BoolNode( need_pf_cmp, BoolTest::ge );
1903       transform_later(need_pf_bol);
1904       IfNode *need_pf_iff = new IfNode( needgc_false, need_pf_bol,
1905                                        PROB_UNLIKELY_MAG(4), COUNT_UNKNOWN );
1906       transform_later(need_pf_iff);
1907 
1908       // true node, add prefetchdistance
1909       Node *need_pf_true = new IfTrueNode( need_pf_iff );
1910       transform_later(need_pf_true);
1911 
1912       Node *need_pf_false = new IfFalseNode( need_pf_iff );
1913       transform_later(need_pf_false);
1914 
1915       Node *new_pf_wmt = new AddPNode( top(), old_pf_wm,
1916                                     _igvn.MakeConX(AllocatePrefetchDistance) );
1917       transform_later(new_pf_wmt );
1918       new_pf_wmt->set_req(0, need_pf_true);
1919 
1920       Node *store_new_wmt = new StorePNode(need_pf_true,
1921                                        contended_phi_rawmem, eden_pf_adr,
1922                                        TypeRawPtr::BOTTOM, new_pf_wmt,
1923                                        MemNode::unordered);
1924       transform_later(store_new_wmt);
1925 
1926       // adding prefetches
1927       pf_phi_abio->init_req( fall_in_path, i_o );
1928 
1929       Node *prefetch_adr;
1930       Node *prefetch;
1931       uint lines = (length != NULL) ? AllocatePrefetchLines : AllocateInstancePrefetchLines;
1932       uint step_size = AllocatePrefetchStepSize;
1933       uint distance = 0;
1934 
1935       for ( uint i = 0; i < lines; i++ ) {
1936         prefetch_adr = new AddPNode( old_pf_wm, new_pf_wmt,
1937                                             _igvn.MakeConX(distance) );
1938         transform_later(prefetch_adr);
1939         prefetch = new PrefetchAllocationNode( i_o, prefetch_adr );
1940         transform_later(prefetch);
1941         distance += step_size;
1942         i_o = prefetch;
1943       }
1944       pf_phi_abio->set_req( pf_path, i_o );
1945 
1946       pf_region->init_req( fall_in_path, need_pf_false );
1947       pf_region->init_req( pf_path, need_pf_true );
1948 
1949       pf_phi_rawmem->init_req( fall_in_path, contended_phi_rawmem );
1950       pf_phi_rawmem->init_req( pf_path, store_new_wmt );
1951 
1952       transform_later(pf_region);
1953       transform_later(pf_phi_rawmem);
1954       transform_later(pf_phi_abio);
1955 
1956       needgc_false = pf_region;
1957       contended_phi_rawmem = pf_phi_rawmem;
1958       i_o = pf_phi_abio;
1959    } else if( UseTLAB && AllocatePrefetchStyle == 3 ) {
1960       // Insert a prefetch instruction for each allocation.
1961       // This code is used to generate 1 prefetch instruction per cache line.
1962 
1963       // Generate several prefetch instructions.
1964       uint lines = (length != NULL) ? AllocatePrefetchLines : AllocateInstancePrefetchLines;
1965       uint step_size = AllocatePrefetchStepSize;
1966       uint distance = AllocatePrefetchDistance;
1967 
1968       // Next cache address.
1969       Node *cache_adr = new AddPNode(old_eden_top, old_eden_top,
1970                                      _igvn.MakeConX(step_size + distance));
1971       transform_later(cache_adr);
1972       cache_adr = new CastP2XNode(needgc_false, cache_adr);
1973       transform_later(cache_adr);
1974       // Address is aligned to execute prefetch to the beginning of cache line size
1975       // (it is important when BIS instruction is used on SPARC as prefetch).
1976       Node* mask = _igvn.MakeConX(~(intptr_t)(step_size-1));
1977       cache_adr = new AndXNode(cache_adr, mask);
1978       transform_later(cache_adr);
1979       cache_adr = new CastX2PNode(cache_adr);
1980       transform_later(cache_adr);
1981 
1982       // Prefetch
1983       Node *prefetch = new PrefetchAllocationNode( contended_phi_rawmem, cache_adr );
1984       prefetch->set_req(0, needgc_false);
1985       transform_later(prefetch);
1986       contended_phi_rawmem = prefetch;
1987       Node *prefetch_adr;
1988       distance = step_size;
1989       for ( uint i = 1; i < lines; i++ ) {
1990         prefetch_adr = new AddPNode( cache_adr, cache_adr,
1991                                             _igvn.MakeConX(distance) );
1992         transform_later(prefetch_adr);
1993         prefetch = new PrefetchAllocationNode( contended_phi_rawmem, prefetch_adr );
1994         transform_later(prefetch);
1995         distance += step_size;
1996         contended_phi_rawmem = prefetch;
1997       }
1998    } else if( AllocatePrefetchStyle > 0 ) {
1999       // Insert a prefetch for each allocation only on the fast-path
2000       Node *prefetch_adr;
2001       Node *prefetch;
2002       // Generate several prefetch instructions.
2003       uint lines = (length != NULL) ? AllocatePrefetchLines : AllocateInstancePrefetchLines;
2004       uint step_size = AllocatePrefetchStepSize;
2005       uint distance = AllocatePrefetchDistance;
2006       for ( uint i = 0; i < lines; i++ ) {
2007         prefetch_adr = new AddPNode( old_eden_top, new_eden_top,
2008                                             _igvn.MakeConX(distance) );
2009         transform_later(prefetch_adr);
2010         prefetch = new PrefetchAllocationNode( i_o, prefetch_adr );
2011         // Do not let it float too high, since if eden_top == eden_end,
2012         // both might be null.
2013         if( i == 0 ) { // Set control for first prefetch, next follows it
2014           prefetch->init_req(0, needgc_false);
2015         }
2016         transform_later(prefetch);
2017         distance += step_size;
2018         i_o = prefetch;
2019       }
2020    }
2021    return i_o;
2022 }
2023 
2024 
2025 void PhaseMacroExpand::expand_allocate(AllocateNode *alloc) {
2026   expand_allocate_common(alloc, NULL,
2027                          OptoRuntime::new_instance_Type(),
2028                          OptoRuntime::new_instance_Java());
2029 }
2030 
2031 void PhaseMacroExpand::expand_allocate_array(AllocateArrayNode *alloc) {
2032   Node* length = alloc->in(AllocateNode::ALength);
2033   InitializeNode* init = alloc->initialization();
2034   Node* klass_node = alloc->in(AllocateNode::KlassNode);
2035   ciKlass* k = _igvn.type(klass_node)->is_klassptr()->klass();
2036   address slow_call_address;  // Address of slow call
2037   if (init != NULL && init->is_complete_with_arraycopy() &&
2038       k->is_type_array_klass()) {
2039     // Don't zero type array during slow allocation in VM since
2040     // it will be initialized later by arraycopy in compiled code.
2041     slow_call_address = OptoRuntime::new_array_nozero_Java();
2042   } else {
2043     slow_call_address = OptoRuntime::new_array_Java();
2044   }
2045   expand_allocate_common(alloc, length,
2046                          OptoRuntime::new_array_Type(),
2047                          slow_call_address);
2048 }
2049 
2050 //-------------------mark_eliminated_box----------------------------------
2051 //
2052 // During EA obj may point to several objects but after few ideal graph
2053 // transformations (CCP) it may point to only one non escaping object
2054 // (but still using phi), corresponding locks and unlocks will be marked
2055 // for elimination. Later obj could be replaced with a new node (new phi)
2056 // and which does not have escape information. And later after some graph
2057 // reshape other locks and unlocks (which were not marked for elimination
2058 // before) are connected to this new obj (phi) but they still will not be
2059 // marked for elimination since new obj has no escape information.
2060 // Mark all associated (same box and obj) lock and unlock nodes for
2061 // elimination if some of them marked already.
2062 void PhaseMacroExpand::mark_eliminated_box(Node* oldbox, Node* obj) {
2063   if (oldbox->as_BoxLock()->is_eliminated())
2064     return; // This BoxLock node was processed already.
2065 
2066   // New implementation (EliminateNestedLocks) has separate BoxLock
2067   // node for each locked region so mark all associated locks/unlocks as
2068   // eliminated even if different objects are referenced in one locked region
2069   // (for example, OSR compilation of nested loop inside locked scope).
2070   if (EliminateNestedLocks ||
2071       oldbox->as_BoxLock()->is_simple_lock_region(NULL, obj)) {
2072     // Box is used only in one lock region. Mark this box as eliminated.
2073     _igvn.hash_delete(oldbox);
2074     oldbox->as_BoxLock()->set_eliminated(); // This changes box's hash value
2075      _igvn.hash_insert(oldbox);
2076 
2077     for (uint i = 0; i < oldbox->outcnt(); i++) {
2078       Node* u = oldbox->raw_out(i);
2079       if (u->is_AbstractLock() && !u->as_AbstractLock()->is_non_esc_obj()) {
2080         AbstractLockNode* alock = u->as_AbstractLock();
2081         // Check lock's box since box could be referenced by Lock's debug info.
2082         if (alock->box_node() == oldbox) {
2083           // Mark eliminated all related locks and unlocks.
2084 #ifdef ASSERT
2085           alock->log_lock_optimization(C, "eliminate_lock_set_non_esc4");
2086 #endif
2087           alock->set_non_esc_obj();
2088         }
2089       }
2090     }
2091     return;
2092   }
2093 
2094   // Create new "eliminated" BoxLock node and use it in monitor debug info
2095   // instead of oldbox for the same object.
2096   BoxLockNode* newbox = oldbox->clone()->as_BoxLock();
2097 
2098   // Note: BoxLock node is marked eliminated only here and it is used
2099   // to indicate that all associated lock and unlock nodes are marked
2100   // for elimination.
2101   newbox->set_eliminated();
2102   transform_later(newbox);
2103 
2104   // Replace old box node with new box for all users of the same object.
2105   for (uint i = 0; i < oldbox->outcnt();) {
2106     bool next_edge = true;
2107 
2108     Node* u = oldbox->raw_out(i);
2109     if (u->is_AbstractLock()) {
2110       AbstractLockNode* alock = u->as_AbstractLock();
2111       if (alock->box_node() == oldbox && alock->obj_node()->eqv_uncast(obj)) {
2112         // Replace Box and mark eliminated all related locks and unlocks.
2113 #ifdef ASSERT
2114         alock->log_lock_optimization(C, "eliminate_lock_set_non_esc5");
2115 #endif
2116         alock->set_non_esc_obj();
2117         _igvn.rehash_node_delayed(alock);
2118         alock->set_box_node(newbox);
2119         next_edge = false;
2120       }
2121     }
2122     if (u->is_FastLock() && u->as_FastLock()->obj_node()->eqv_uncast(obj)) {
2123       FastLockNode* flock = u->as_FastLock();
2124       assert(flock->box_node() == oldbox, "sanity");
2125       _igvn.rehash_node_delayed(flock);
2126       flock->set_box_node(newbox);
2127       next_edge = false;
2128     }
2129 
2130     // Replace old box in monitor debug info.
2131     if (u->is_SafePoint() && u->as_SafePoint()->jvms()) {
2132       SafePointNode* sfn = u->as_SafePoint();
2133       JVMState* youngest_jvms = sfn->jvms();
2134       int max_depth = youngest_jvms->depth();
2135       for (int depth = 1; depth <= max_depth; depth++) {
2136         JVMState* jvms = youngest_jvms->of_depth(depth);
2137         int num_mon  = jvms->nof_monitors();
2138         // Loop over monitors
2139         for (int idx = 0; idx < num_mon; idx++) {
2140           Node* obj_node = sfn->monitor_obj(jvms, idx);
2141           Node* box_node = sfn->monitor_box(jvms, idx);
2142           if (box_node == oldbox && obj_node->eqv_uncast(obj)) {
2143             int j = jvms->monitor_box_offset(idx);
2144             _igvn.replace_input_of(u, j, newbox);
2145             next_edge = false;
2146           }
2147         }
2148       }
2149     }
2150     if (next_edge) i++;
2151   }
2152 }
2153 
2154 //-----------------------mark_eliminated_locking_nodes-----------------------
2155 void PhaseMacroExpand::mark_eliminated_locking_nodes(AbstractLockNode *alock) {
2156   if (EliminateNestedLocks) {
2157     if (alock->is_nested()) {
2158        assert(alock->box_node()->as_BoxLock()->is_eliminated(), "sanity");
2159        return;
2160     } else if (!alock->is_non_esc_obj()) { // Not eliminated or coarsened
2161       // Only Lock node has JVMState needed here.
2162       // Not that preceding claim is documented anywhere else.
2163       if (alock->jvms() != NULL) {
2164         if (alock->as_Lock()->is_nested_lock_region()) {
2165           // Mark eliminated related nested locks and unlocks.
2166           Node* obj = alock->obj_node();
2167           BoxLockNode* box_node = alock->box_node()->as_BoxLock();
2168           assert(!box_node->is_eliminated(), "should not be marked yet");
2169           // Note: BoxLock node is marked eliminated only here
2170           // and it is used to indicate that all associated lock
2171           // and unlock nodes are marked for elimination.
2172           box_node->set_eliminated(); // Box's hash is always NO_HASH here
2173           for (uint i = 0; i < box_node->outcnt(); i++) {
2174             Node* u = box_node->raw_out(i);
2175             if (u->is_AbstractLock()) {
2176               alock = u->as_AbstractLock();
2177               if (alock->box_node() == box_node) {
2178                 // Verify that this Box is referenced only by related locks.
2179                 assert(alock->obj_node()->eqv_uncast(obj), "");
2180                 // Mark all related locks and unlocks.
2181 #ifdef ASSERT
2182                 alock->log_lock_optimization(C, "eliminate_lock_set_nested");
2183 #endif
2184                 alock->set_nested();
2185               }
2186             }
2187           }
2188         } else {
2189 #ifdef ASSERT
2190           alock->log_lock_optimization(C, "eliminate_lock_NOT_nested_lock_region");
2191           if (C->log() != NULL)
2192             alock->as_Lock()->is_nested_lock_region(C); // rerun for debugging output
2193 #endif
2194         }
2195       }
2196       return;
2197     }
2198     // Process locks for non escaping object
2199     assert(alock->is_non_esc_obj(), "");
2200   } // EliminateNestedLocks
2201 
2202   if (alock->is_non_esc_obj()) { // Lock is used for non escaping object
2203     // Look for all locks of this object and mark them and
2204     // corresponding BoxLock nodes as eliminated.
2205     Node* obj = alock->obj_node();
2206     for (uint j = 0; j < obj->outcnt(); j++) {
2207       Node* o = obj->raw_out(j);
2208       if (o->is_AbstractLock() &&
2209           o->as_AbstractLock()->obj_node()->eqv_uncast(obj)) {
2210         alock = o->as_AbstractLock();
2211         Node* box = alock->box_node();
2212         // Replace old box node with new eliminated box for all users
2213         // of the same object and mark related locks as eliminated.
2214         mark_eliminated_box(box, obj);
2215       }
2216     }
2217   }
2218 }
2219 
2220 // we have determined that this lock/unlock can be eliminated, we simply
2221 // eliminate the node without expanding it.
2222 //
2223 // Note:  The membar's associated with the lock/unlock are currently not
2224 //        eliminated.  This should be investigated as a future enhancement.
2225 //
2226 bool PhaseMacroExpand::eliminate_locking_node(AbstractLockNode *alock) {
2227 
2228   if (!alock->is_eliminated()) {
2229     return false;
2230   }
2231 #ifdef ASSERT
2232   if (!alock->is_coarsened()) {
2233     // Check that new "eliminated" BoxLock node is created.
2234     BoxLockNode* oldbox = alock->box_node()->as_BoxLock();
2235     assert(oldbox->is_eliminated(), "should be done already");
2236   }
2237 #endif
2238 
2239   alock->log_lock_optimization(C, "eliminate_lock");
2240 
2241 #ifndef PRODUCT
2242   if (PrintEliminateLocks) {
2243     if (alock->is_Lock()) {
2244       tty->print_cr("++++ Eliminated: %d Lock", alock->_idx);
2245     } else {
2246       tty->print_cr("++++ Eliminated: %d Unlock", alock->_idx);
2247     }
2248   }
2249 #endif
2250 
2251   Node* mem  = alock->in(TypeFunc::Memory);
2252   Node* ctrl = alock->in(TypeFunc::Control);
2253 
2254   extract_call_projections(alock);
2255   // There are 2 projections from the lock.  The lock node will
2256   // be deleted when its last use is subsumed below.
2257   assert(alock->outcnt() == 2 &&
2258          _fallthroughproj != NULL &&
2259          _memproj_fallthrough != NULL,
2260          "Unexpected projections from Lock/Unlock");
2261 
2262   Node* fallthroughproj = _fallthroughproj;
2263   Node* memproj_fallthrough = _memproj_fallthrough;
2264 
2265   // The memory projection from a lock/unlock is RawMem
2266   // The input to a Lock is merged memory, so extract its RawMem input
2267   // (unless the MergeMem has been optimized away.)
2268   if (alock->is_Lock()) {
2269     // Seach for MemBarAcquireLock node and delete it also.
2270     MemBarNode* membar = fallthroughproj->unique_ctrl_out()->as_MemBar();
2271     assert(membar != NULL && membar->Opcode() == Op_MemBarAcquireLock, "");
2272     Node* ctrlproj = membar->proj_out(TypeFunc::Control);
2273     Node* memproj = membar->proj_out(TypeFunc::Memory);
2274     _igvn.replace_node(ctrlproj, fallthroughproj);
2275     _igvn.replace_node(memproj, memproj_fallthrough);
2276 
2277     // Delete FastLock node also if this Lock node is unique user
2278     // (a loop peeling may clone a Lock node).
2279     Node* flock = alock->as_Lock()->fastlock_node();
2280     if (flock->outcnt() == 1) {
2281       assert(flock->unique_out() == alock, "sanity");
2282       _igvn.replace_node(flock, top());
2283     }
2284   }
2285 
2286   // Seach for MemBarReleaseLock node and delete it also.
2287   if (alock->is_Unlock() && ctrl != NULL && ctrl->is_Proj() &&
2288       ctrl->in(0)->is_MemBar()) {
2289     MemBarNode* membar = ctrl->in(0)->as_MemBar();
2290     assert(membar->Opcode() == Op_MemBarReleaseLock &&
2291            mem->is_Proj() && membar == mem->in(0), "");
2292     _igvn.replace_node(fallthroughproj, ctrl);
2293     _igvn.replace_node(memproj_fallthrough, mem);
2294     fallthroughproj = ctrl;
2295     memproj_fallthrough = mem;
2296     ctrl = membar->in(TypeFunc::Control);
2297     mem  = membar->in(TypeFunc::Memory);
2298   }
2299 
2300   _igvn.replace_node(fallthroughproj, ctrl);
2301   _igvn.replace_node(memproj_fallthrough, mem);
2302   return true;
2303 }
2304 
2305 
2306 //------------------------------expand_lock_node----------------------
2307 void PhaseMacroExpand::expand_lock_node(LockNode *lock) {
2308 
2309   Node* ctrl = lock->in(TypeFunc::Control);
2310   Node* mem = lock->in(TypeFunc::Memory);
2311   Node* obj = lock->obj_node();
2312   Node* box = lock->box_node();
2313   Node* flock = lock->fastlock_node();
2314 
2315   assert(!box->as_BoxLock()->is_eliminated(), "sanity");
2316 
2317   // Make the merge point
2318   Node *region;
2319   Node *mem_phi;
2320   Node *slow_path;
2321 
2322   if (UseOptoBiasInlining) {
2323     /*
2324      *  See the full description in MacroAssembler::biased_locking_enter().
2325      *
2326      *  if( (mark_word & biased_lock_mask) == biased_lock_pattern ) {
2327      *    // The object is biased.
2328      *    proto_node = klass->prototype_header;
2329      *    o_node = thread | proto_node;
2330      *    x_node = o_node ^ mark_word;
2331      *    if( (x_node & ~age_mask) == 0 ) { // Biased to the current thread ?
2332      *      // Done.
2333      *    } else {
2334      *      if( (x_node & biased_lock_mask) != 0 ) {
2335      *        // The klass's prototype header is no longer biased.
2336      *        cas(&mark_word, mark_word, proto_node)
2337      *        goto cas_lock;
2338      *      } else {
2339      *        // The klass's prototype header is still biased.
2340      *        if( (x_node & epoch_mask) != 0 ) { // Expired epoch?
2341      *          old = mark_word;
2342      *          new = o_node;
2343      *        } else {
2344      *          // Different thread or anonymous biased.
2345      *          old = mark_word & (epoch_mask | age_mask | biased_lock_mask);
2346      *          new = thread | old;
2347      *        }
2348      *        // Try to rebias.
2349      *        if( cas(&mark_word, old, new) == 0 ) {
2350      *          // Done.
2351      *        } else {
2352      *          goto slow_path; // Failed.
2353      *        }
2354      *      }
2355      *    }
2356      *  } else {
2357      *    // The object is not biased.
2358      *    cas_lock:
2359      *    if( FastLock(obj) == 0 ) {
2360      *      // Done.
2361      *    } else {
2362      *      slow_path:
2363      *      OptoRuntime::complete_monitor_locking_Java(obj);
2364      *    }
2365      *  }
2366      */
2367 
2368     region  = new RegionNode(5);
2369     // create a Phi for the memory state
2370     mem_phi = new PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2371 
2372     Node* fast_lock_region  = new RegionNode(3);
2373     Node* fast_lock_mem_phi = new PhiNode( fast_lock_region, Type::MEMORY, TypeRawPtr::BOTTOM);
2374 
2375     // First, check mark word for the biased lock pattern.
2376     Node* mark_node = make_load(ctrl, mem, obj, oopDesc::mark_offset_in_bytes(), TypeX_X, TypeX_X->basic_type());
2377 
2378     // Get fast path - mark word has the biased lock pattern.
2379     ctrl = opt_bits_test(ctrl, fast_lock_region, 1, mark_node,
2380                          markOopDesc::biased_lock_mask_in_place,
2381                          markOopDesc::biased_lock_pattern, true);
2382     // fast_lock_region->in(1) is set to slow path.
2383     fast_lock_mem_phi->init_req(1, mem);
2384 
2385     // Now check that the lock is biased to the current thread and has
2386     // the same epoch and bias as Klass::_prototype_header.
2387 
2388     // Special-case a fresh allocation to avoid building nodes:
2389     Node* klass_node = AllocateNode::Ideal_klass(obj, &_igvn);
2390     if (klass_node == NULL) {
2391       Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes());
2392       klass_node = transform_later(LoadKlassNode::make(_igvn, NULL, mem, k_adr, _igvn.type(k_adr)->is_ptr()));
2393 #ifdef _LP64
2394       if (UseCompressedClassPointers && klass_node->is_DecodeNKlass()) {
2395         assert(klass_node->in(1)->Opcode() == Op_LoadNKlass, "sanity");
2396         klass_node->in(1)->init_req(0, ctrl);
2397       } else
2398 #endif
2399       klass_node->init_req(0, ctrl);
2400     }
2401     Node *proto_node = make_load(ctrl, mem, klass_node, in_bytes(Klass::prototype_header_offset()), TypeX_X, TypeX_X->basic_type());
2402 
2403     Node* thread = transform_later(new ThreadLocalNode());
2404     Node* cast_thread = transform_later(new CastP2XNode(ctrl, thread));
2405     Node* o_node = transform_later(new OrXNode(cast_thread, proto_node));
2406     Node* x_node = transform_later(new XorXNode(o_node, mark_node));
2407 
2408     // Get slow path - mark word does NOT match the value.
2409     Node* not_biased_ctrl =  opt_bits_test(ctrl, region, 3, x_node,
2410                                       (~markOopDesc::age_mask_in_place), 0);
2411     // region->in(3) is set to fast path - the object is biased to the current thread.
2412     mem_phi->init_req(3, mem);
2413 
2414 
2415     // Mark word does NOT match the value (thread | Klass::_prototype_header).
2416 
2417 
2418     // First, check biased pattern.
2419     // Get fast path - _prototype_header has the same biased lock pattern.
2420     ctrl =  opt_bits_test(not_biased_ctrl, fast_lock_region, 2, x_node,
2421                           markOopDesc::biased_lock_mask_in_place, 0, true);
2422 
2423     not_biased_ctrl = fast_lock_region->in(2); // Slow path
2424     // fast_lock_region->in(2) - the prototype header is no longer biased
2425     // and we have to revoke the bias on this object.
2426     // We are going to try to reset the mark of this object to the prototype
2427     // value and fall through to the CAS-based locking scheme.
2428     Node* adr = basic_plus_adr(obj, oopDesc::mark_offset_in_bytes());
2429     Node* cas = new StoreXConditionalNode(not_biased_ctrl, mem, adr,
2430                                           proto_node, mark_node);
2431     transform_later(cas);
2432     Node* proj = transform_later(new SCMemProjNode(cas));
2433     fast_lock_mem_phi->init_req(2, proj);
2434 
2435 
2436     // Second, check epoch bits.
2437     Node* rebiased_region  = new RegionNode(3);
2438     Node* old_phi = new PhiNode( rebiased_region, TypeX_X);
2439     Node* new_phi = new PhiNode( rebiased_region, TypeX_X);
2440 
2441     // Get slow path - mark word does NOT match epoch bits.
2442     Node* epoch_ctrl =  opt_bits_test(ctrl, rebiased_region, 1, x_node,
2443                                       markOopDesc::epoch_mask_in_place, 0);
2444     // The epoch of the current bias is not valid, attempt to rebias the object
2445     // toward the current thread.
2446     rebiased_region->init_req(2, epoch_ctrl);
2447     old_phi->init_req(2, mark_node);
2448     new_phi->init_req(2, o_node);
2449 
2450     // rebiased_region->in(1) is set to fast path.
2451     // The epoch of the current bias is still valid but we know
2452     // nothing about the owner; it might be set or it might be clear.
2453     Node* cmask   = MakeConX(markOopDesc::biased_lock_mask_in_place |
2454                              markOopDesc::age_mask_in_place |
2455                              markOopDesc::epoch_mask_in_place);
2456     Node* old = transform_later(new AndXNode(mark_node, cmask));
2457     cast_thread = transform_later(new CastP2XNode(ctrl, thread));
2458     Node* new_mark = transform_later(new OrXNode(cast_thread, old));
2459     old_phi->init_req(1, old);
2460     new_phi->init_req(1, new_mark);
2461 
2462     transform_later(rebiased_region);
2463     transform_later(old_phi);
2464     transform_later(new_phi);
2465 
2466     // Try to acquire the bias of the object using an atomic operation.
2467     // If this fails we will go in to the runtime to revoke the object's bias.
2468     cas = new StoreXConditionalNode(rebiased_region, mem, adr, new_phi, old_phi);
2469     transform_later(cas);
2470     proj = transform_later(new SCMemProjNode(cas));
2471 
2472     // Get slow path - Failed to CAS.
2473     not_biased_ctrl = opt_bits_test(rebiased_region, region, 4, cas, 0, 0);
2474     mem_phi->init_req(4, proj);
2475     // region->in(4) is set to fast path - the object is rebiased to the current thread.
2476 
2477     // Failed to CAS.
2478     slow_path  = new RegionNode(3);
2479     Node *slow_mem = new PhiNode( slow_path, Type::MEMORY, TypeRawPtr::BOTTOM);
2480 
2481     slow_path->init_req(1, not_biased_ctrl); // Capture slow-control
2482     slow_mem->init_req(1, proj);
2483 
2484     // Call CAS-based locking scheme (FastLock node).
2485 
2486     transform_later(fast_lock_region);
2487     transform_later(fast_lock_mem_phi);
2488 
2489     // Get slow path - FastLock failed to lock the object.
2490     ctrl = opt_bits_test(fast_lock_region, region, 2, flock, 0, 0);
2491     mem_phi->init_req(2, fast_lock_mem_phi);
2492     // region->in(2) is set to fast path - the object is locked to the current thread.
2493 
2494     slow_path->init_req(2, ctrl); // Capture slow-control
2495     slow_mem->init_req(2, fast_lock_mem_phi);
2496 
2497     transform_later(slow_path);
2498     transform_later(slow_mem);
2499     // Reset lock's memory edge.
2500     lock->set_req(TypeFunc::Memory, slow_mem);
2501 
2502   } else {
2503     region  = new RegionNode(3);
2504     // create a Phi for the memory state
2505     mem_phi = new PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2506 
2507     // Optimize test; set region slot 2
2508     slow_path = opt_bits_test(ctrl, region, 2, flock, 0, 0);
2509     mem_phi->init_req(2, mem);
2510   }
2511 
2512   // Make slow path call
2513   CallNode *call = make_slow_call((CallNode *) lock, OptoRuntime::complete_monitor_enter_Type(),
2514                                   OptoRuntime::complete_monitor_locking_Java(), NULL, slow_path,
2515                                   obj, box, NULL);
2516 
2517   extract_call_projections(call);
2518 
2519   // Slow path can only throw asynchronous exceptions, which are always
2520   // de-opted.  So the compiler thinks the slow-call can never throw an
2521   // exception.  If it DOES throw an exception we would need the debug
2522   // info removed first (since if it throws there is no monitor).
2523   assert ( _ioproj_fallthrough == NULL && _ioproj_catchall == NULL &&
2524            _memproj_catchall == NULL && _catchallcatchproj == NULL, "Unexpected projection from Lock");
2525 
2526   // Capture slow path
2527   // disconnect fall-through projection from call and create a new one
2528   // hook up users of fall-through projection to region
2529   Node *slow_ctrl = _fallthroughproj->clone();
2530   transform_later(slow_ctrl);
2531   _igvn.hash_delete(_fallthroughproj);
2532   _fallthroughproj->disconnect_inputs(NULL, C);
2533   region->init_req(1, slow_ctrl);
2534   // region inputs are now complete
2535   transform_later(region);
2536   _igvn.replace_node(_fallthroughproj, region);
2537 
2538   Node *memproj = transform_later(new ProjNode(call, TypeFunc::Memory));
2539   mem_phi->init_req(1, memproj );
2540   transform_later(mem_phi);
2541   _igvn.replace_node(_memproj_fallthrough, mem_phi);
2542 }
2543 
2544 //------------------------------expand_unlock_node----------------------
2545 void PhaseMacroExpand::expand_unlock_node(UnlockNode *unlock) {
2546 
2547   Node* ctrl = unlock->in(TypeFunc::Control);
2548   Node* mem = unlock->in(TypeFunc::Memory);
2549   Node* obj = unlock->obj_node();
2550   Node* box = unlock->box_node();
2551 
2552   assert(!box->as_BoxLock()->is_eliminated(), "sanity");
2553 
2554   // No need for a null check on unlock
2555 
2556   // Make the merge point
2557   Node *region;
2558   Node *mem_phi;
2559 
2560   if (UseOptoBiasInlining) {
2561     // Check for biased locking unlock case, which is a no-op.
2562     // See the full description in MacroAssembler::biased_locking_exit().
2563     region  = new RegionNode(4);
2564     // create a Phi for the memory state
2565     mem_phi = new PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2566     mem_phi->init_req(3, mem);
2567 
2568     Node* mark_node = make_load(ctrl, mem, obj, oopDesc::mark_offset_in_bytes(), TypeX_X, TypeX_X->basic_type());
2569     ctrl = opt_bits_test(ctrl, region, 3, mark_node,
2570                          markOopDesc::biased_lock_mask_in_place,
2571                          markOopDesc::biased_lock_pattern);
2572   } else {
2573     region  = new RegionNode(3);
2574     // create a Phi for the memory state
2575     mem_phi = new PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2576   }
2577 
2578   FastUnlockNode *funlock = new FastUnlockNode( ctrl, obj, box );
2579   funlock = transform_later( funlock )->as_FastUnlock();
2580   // Optimize test; set region slot 2
2581   Node *slow_path = opt_bits_test(ctrl, region, 2, funlock, 0, 0);
2582   Node *thread = transform_later(new ThreadLocalNode());
2583 
2584   CallNode *call = make_slow_call((CallNode *) unlock, OptoRuntime::complete_monitor_exit_Type(),
2585                                   CAST_FROM_FN_PTR(address, SharedRuntime::complete_monitor_unlocking_C),
2586                                   "complete_monitor_unlocking_C", slow_path, obj, box, thread);
2587 
2588   extract_call_projections(call);
2589 
2590   assert ( _ioproj_fallthrough == NULL && _ioproj_catchall == NULL &&
2591            _memproj_catchall == NULL && _catchallcatchproj == NULL, "Unexpected projection from Lock");
2592 
2593   // No exceptions for unlocking
2594   // Capture slow path
2595   // disconnect fall-through projection from call and create a new one
2596   // hook up users of fall-through projection to region
2597   Node *slow_ctrl = _fallthroughproj->clone();
2598   transform_later(slow_ctrl);
2599   _igvn.hash_delete(_fallthroughproj);
2600   _fallthroughproj->disconnect_inputs(NULL, C);
2601   region->init_req(1, slow_ctrl);
2602   // region inputs are now complete
2603   transform_later(region);
2604   _igvn.replace_node(_fallthroughproj, region);
2605 
2606   Node *memproj = transform_later(new ProjNode(call, TypeFunc::Memory) );
2607   mem_phi->init_req(1, memproj );
2608   mem_phi->init_req(2, mem);
2609   transform_later(mem_phi);
2610   _igvn.replace_node(_memproj_fallthrough, mem_phi);
2611 }
2612 
2613 //---------------------------eliminate_macro_nodes----------------------
2614 // Eliminate scalar replaced allocations and associated locks.
2615 void PhaseMacroExpand::eliminate_macro_nodes() {
2616   if (C->macro_count() == 0)
2617     return;
2618 
2619   // First, attempt to eliminate locks
2620   int cnt = C->macro_count();
2621   for (int i=0; i < cnt; i++) {
2622     Node *n = C->macro_node(i);
2623     if (n->is_AbstractLock()) { // Lock and Unlock nodes
2624       // Before elimination mark all associated (same box and obj)
2625       // lock and unlock nodes.
2626       mark_eliminated_locking_nodes(n->as_AbstractLock());
2627     }
2628   }
2629   bool progress = true;
2630   while (progress) {
2631     progress = false;
2632     for (int i = C->macro_count(); i > 0; i--) {
2633       Node * n = C->macro_node(i-1);
2634       bool success = false;
2635       debug_only(int old_macro_count = C->macro_count(););
2636       if (n->is_AbstractLock()) {
2637         success = eliminate_locking_node(n->as_AbstractLock());
2638       }
2639       assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
2640       progress = progress || success;
2641     }
2642   }
2643   // Next, attempt to eliminate allocations
2644   _has_locks = false;
2645   progress = true;
2646   while (progress) {
2647     progress = false;
2648     for (int i = C->macro_count(); i > 0; i--) {
2649       Node * n = C->macro_node(i-1);
2650       bool success = false;
2651       debug_only(int old_macro_count = C->macro_count(););
2652       switch (n->class_id()) {
2653       case Node::Class_Allocate:
2654       case Node::Class_AllocateArray:
2655         success = eliminate_allocate_node(n->as_Allocate());
2656         break;
2657       case Node::Class_CallStaticJava:
2658         success = eliminate_boxing_node(n->as_CallStaticJava());
2659         break;
2660       case Node::Class_Lock:
2661       case Node::Class_Unlock:
2662         assert(!n->as_AbstractLock()->is_eliminated(), "sanity");
2663         _has_locks = true;
2664         break;
2665       case Node::Class_ArrayCopy:
2666         break;
2667       case Node::Class_OuterStripMinedLoop:
2668         break;
2669       default:
2670         assert(n->Opcode() == Op_LoopLimit ||
2671                n->Opcode() == Op_Opaque1   ||
2672                n->Opcode() == Op_Opaque2   ||
2673                n->Opcode() == Op_Opaque3   ||
2674                n->Opcode() == Op_Opaque4, "unknown node type in macro list");
2675       }
2676       assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
2677       progress = progress || success;
2678     }
2679   }
2680 }
2681 
2682 //------------------------------expand_macro_nodes----------------------
2683 //  Returns true if a failure occurred.
2684 bool PhaseMacroExpand::expand_macro_nodes() {
2685   // Last attempt to eliminate macro nodes.
2686   eliminate_macro_nodes();
2687 
2688   // Make sure expansion will not cause node limit to be exceeded.
2689   // Worst case is a macro node gets expanded into about 200 nodes.
2690   // Allow 50% more for optimization.
2691   if (C->check_node_count(C->macro_count() * 300, "out of nodes before macro expansion" ) )
2692     return true;
2693 
2694   // Eliminate Opaque and LoopLimit nodes. Do it after all loop optimizations.
2695   bool progress = true;
2696   while (progress) {
2697     progress = false;
2698     for (int i = C->macro_count(); i > 0; i--) {
2699       Node * n = C->macro_node(i-1);
2700       bool success = false;
2701       debug_only(int old_macro_count = C->macro_count(););
2702       if (n->Opcode() == Op_LoopLimit) {
2703         // Remove it from macro list and put on IGVN worklist to optimize.
2704         C->remove_macro_node(n);
2705         _igvn._worklist.push(n);
2706         success = true;
2707       } else if (n->Opcode() == Op_CallStaticJava) {
2708         // Remove it from macro list and put on IGVN worklist to optimize.
2709         C->remove_macro_node(n);
2710         _igvn._worklist.push(n);
2711         success = true;
2712       } else if (n->Opcode() == Op_Opaque1 || n->Opcode() == Op_Opaque2) {
2713         _igvn.replace_node(n, n->in(1));
2714         success = true;
2715 #if INCLUDE_RTM_OPT
2716       } else if ((n->Opcode() == Op_Opaque3) && ((Opaque3Node*)n)->rtm_opt()) {
2717         assert(C->profile_rtm(), "should be used only in rtm deoptimization code");
2718         assert((n->outcnt() == 1) && n->unique_out()->is_Cmp(), "");
2719         Node* cmp = n->unique_out();
2720 #ifdef ASSERT
2721         // Validate graph.
2722         assert((cmp->outcnt() == 1) && cmp->unique_out()->is_Bool(), "");
2723         BoolNode* bol = cmp->unique_out()->as_Bool();
2724         assert((bol->outcnt() == 1) && bol->unique_out()->is_If() &&
2725                (bol->_test._test == BoolTest::ne), "");
2726         IfNode* ifn = bol->unique_out()->as_If();
2727         assert((ifn->outcnt() == 2) &&
2728                ifn->proj_out(1)->is_uncommon_trap_proj(Deoptimization::Reason_rtm_state_change) != NULL, "");
2729 #endif
2730         Node* repl = n->in(1);
2731         if (!_has_locks) {
2732           // Remove RTM state check if there are no locks in the code.
2733           // Replace input to compare the same value.
2734           repl = (cmp->in(1) == n) ? cmp->in(2) : cmp->in(1);
2735         }
2736         _igvn.replace_node(n, repl);
2737         success = true;
2738 #endif
2739       } else if (n->Opcode() == Op_Opaque4) {
2740         _igvn.replace_node(n, n->in(2));
2741         success = true;
2742       } else if (n->Opcode() == Op_OuterStripMinedLoop) {
2743         n->as_OuterStripMinedLoop()->adjust_strip_mined_loop(&_igvn);
2744         C->remove_macro_node(n);
2745         success = true;
2746       }
2747       assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
2748       progress = progress || success;
2749     }
2750   }
2751 
2752   // expand arraycopy "macro" nodes first
2753   // For ReduceBulkZeroing, we must first process all arraycopy nodes
2754   // before the allocate nodes are expanded.
2755   int macro_idx = C->macro_count() - 1;
2756   while (macro_idx >= 0) {
2757     Node * n = C->macro_node(macro_idx);
2758     assert(n->is_macro(), "only macro nodes expected here");
2759     if (_igvn.type(n) == Type::TOP || n->in(0)->is_top() ) {
2760       // node is unreachable, so don't try to expand it
2761       C->remove_macro_node(n);
2762     } else if (n->is_ArrayCopy()){
2763       int macro_count = C->macro_count();
2764       expand_arraycopy_node(n->as_ArrayCopy());
2765       assert(C->macro_count() < macro_count, "must have deleted a node from macro list");
2766     }
2767     if (C->failing())  return true;
2768     macro_idx --;
2769   }
2770 
2771   // expand "macro" nodes
2772   // nodes are removed from the macro list as they are processed
2773   while (C->macro_count() > 0) {
2774     int macro_count = C->macro_count();
2775     Node * n = C->macro_node(macro_count-1);
2776     assert(n->is_macro(), "only macro nodes expected here");
2777     if (_igvn.type(n) == Type::TOP || n->in(0)->is_top() ) {
2778       // node is unreachable, so don't try to expand it
2779       C->remove_macro_node(n);
2780       continue;
2781     }
2782     switch (n->class_id()) {
2783     case Node::Class_Allocate:
2784       expand_allocate(n->as_Allocate());
2785       break;
2786     case Node::Class_AllocateArray:
2787       expand_allocate_array(n->as_AllocateArray());
2788       break;
2789     case Node::Class_Lock:
2790       expand_lock_node(n->as_Lock());
2791       break;
2792     case Node::Class_Unlock:
2793       expand_unlock_node(n->as_Unlock());
2794       break;
2795     default:
2796       assert(false, "unknown node type in macro list");
2797     }
2798     assert(C->macro_count() < macro_count, "must have deleted a node from macro list");
2799     if (C->failing())  return true;
2800   }
2801 
2802   _igvn.set_delay_transform(false);
2803   _igvn.optimize();
2804   if (C->failing())  return true;
2805   return false;
2806 }