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 /*

  * Copyright (c) 2005, 2009, Oracle and/or its affiliates. All rights reserved.

  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

  *

  * This code is free software; you can redistribute it and/or modify it

  * under the terms of the GNU General Public License version 2 only, as

  * published by the Free Software Foundation.

  *

  * This code is distributed in the hope that it will be useful, but WITHOUT

  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

  * version 2 for more details (a copy is included in the LICENSE file that

  * accompanied this code).

  *

  * You should have received a copy of the GNU General Public License version

  * 2 along with this work; if not, write to the Free Software Foundation,

  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

  *

  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

  * or visit www.oracle.com if you need additional information or have any

  * questions.

  *

  */

 #include "incls/_precompiled.incl"

 #include "incls/_macro.cpp.incl"

 //

 // Replace any references to "oldref" in inputs to "use" with "newref".

 // Returns the number of replacements made.

 //

 int PhaseMacroExpand::replace_input(Node *use, Node *oldref, Node *newref) {

   int nreplacements = 0;

   uint req = use->req();

   for (uint j = 0; j < use->len(); j++) {

     Node *uin = use->in(j);

     if (uin == oldref) {

       if (j < req)

         use->set_req(j, newref);

       else

         use->set_prec(j, newref);

       nreplacements++;

     } else if (j >= req && uin == NULL) {

       break;

     }

   }

   return nreplacements;

 }

 void PhaseMacroExpand::copy_call_debug_info(CallNode *oldcall, CallNode * newcall) {

   // Copy debug information and adjust JVMState information

   uint old_dbg_start = oldcall->tf()->domain()->cnt();

   uint new_dbg_start = newcall->tf()->domain()->cnt();

   int jvms_adj  = new_dbg_start - old_dbg_start;

   assert (new_dbg_start == newcall->req(), "argument count mismatch");

   Dict* sosn_map = new Dict(cmpkey,hashkey);

   for (uint i = old_dbg_start; i < oldcall->req(); i++) {

     Node* old_in = oldcall->in(i);

     // Clone old SafePointScalarObjectNodes, adjusting their field contents.

     if (old_in != NULL && old_in->is_SafePointScalarObject()) {

       SafePointScalarObjectNode* old_sosn = old_in->as_SafePointScalarObject();

       uint old_unique = C->unique();

       Node* new_in = old_sosn->clone(jvms_adj, sosn_map);

       if (old_unique != C->unique()) {

         new_in->set_req(0, newcall->in(0)); // reset control edge

         new_in = transform_later(new_in); // Register new node.

       }

       old_in = new_in;

     }

     newcall->add_req(old_in);

   }

   newcall->set_jvms(oldcall->jvms());

   for (JVMState *jvms = newcall->jvms(); jvms != NULL; jvms = jvms->caller()) {

     jvms->set_map(newcall);

     jvms->set_locoff(jvms->locoff()+jvms_adj);

     jvms->set_stkoff(jvms->stkoff()+jvms_adj);

     jvms->set_monoff(jvms->monoff()+jvms_adj);

     jvms->set_scloff(jvms->scloff()+jvms_adj);

     jvms->set_endoff(jvms->endoff()+jvms_adj);

   }

 }

 Node* PhaseMacroExpand::opt_bits_test(Node* ctrl, Node* region, int edge, Node* word, int mask, int bits, bool return_fast_path) {

   Node* cmp;

   if (mask != 0) {

     Node* and_node = transform_later(new (C, 3) AndXNode(word, MakeConX(mask)));

     cmp = transform_later(new (C, 3) CmpXNode(and_node, MakeConX(bits)));

   } else {

     cmp = word;

   }

   Node* bol = transform_later(new (C, 2) BoolNode(cmp, BoolTest::ne));

   IfNode* iff = new (C, 2) IfNode( ctrl, bol, PROB_MIN, COUNT_UNKNOWN );

   transform_later(iff);

   // Fast path taken.

   Node *fast_taken = transform_later( new (C, 1) IfFalseNode(iff) );

   // Fast path not-taken, i.e. slow path

   Node *slow_taken = transform_later( new (C, 1) IfTrueNode(iff) );

   if (return_fast_path) {

     region->init_req(edge, slow_taken); // Capture slow-control

     return fast_taken;

   } else {

     region->init_req(edge, fast_taken); // Capture fast-control

     return slow_taken;

   }

 }

 //--------------------copy_predefined_input_for_runtime_call--------------------

 void PhaseMacroExpand::copy_predefined_input_for_runtime_call(Node * ctrl, CallNode* oldcall, CallNode* call) {

   // Set fixed predefined input arguments

   call->init_req( TypeFunc::Control, ctrl );

   call->init_req( TypeFunc::I_O    , oldcall->in( TypeFunc::I_O) );

   call->init_req( TypeFunc::Memory , oldcall->in( TypeFunc::Memory ) ); // ?????

   call->init_req( TypeFunc::ReturnAdr, oldcall->in( TypeFunc::ReturnAdr ) );

   call->init_req( TypeFunc::FramePtr, oldcall->in( TypeFunc::FramePtr ) );

 }

 //------------------------------make_slow_call---------------------------------

 CallNode* PhaseMacroExpand::make_slow_call(CallNode *oldcall, const TypeFunc* slow_call_type, address slow_call, const char* leaf_name, Node* slow_path, Node* parm0, Node* parm1) {

   // Slow-path call

   int size = slow_call_type->domain()->cnt();

  CallNode *call = leaf_name

    ? (CallNode*)new (C, size) CallLeafNode      ( slow_call_type, slow_call, leaf_name, TypeRawPtr::BOTTOM )

    : (CallNode*)new (C, size) CallStaticJavaNode( slow_call_type, slow_call, OptoRuntime::stub_name(slow_call), oldcall->jvms()->bci(), TypeRawPtr::BOTTOM );

   // Slow path call has no side-effects, uses few values

   copy_predefined_input_for_runtime_call(slow_path, oldcall, call );

   if (parm0 != NULL)  call->init_req(TypeFunc::Parms+0, parm0);

   if (parm1 != NULL)  call->init_req(TypeFunc::Parms+1, parm1);

   copy_call_debug_info(oldcall, call);

   call->set_cnt(PROB_UNLIKELY_MAG(4));  // Same effect as RC_UNCOMMON.

   _igvn.replace_node(oldcall, call);

   transform_later(call);

   return call;

 }

 void PhaseMacroExpand::extract_call_projections(CallNode *call) {

   _fallthroughproj = NULL;

   _fallthroughcatchproj = NULL;

   _ioproj_fallthrough = NULL;

   _ioproj_catchall = NULL;

   _catchallcatchproj = NULL;

   _memproj_fallthrough = NULL;

   _memproj_catchall = NULL;

   _resproj = NULL;

   for (DUIterator_Fast imax, i = call->fast_outs(imax); i < imax; i++) {

     ProjNode *pn = call->fast_out(i)->as_Proj();

     switch (pn->_con) {

       case TypeFunc::Control:

       {

         // For Control (fallthrough) and I_O (catch_all_index) we have CatchProj -> Catch -> Proj

         _fallthroughproj = pn;

         DUIterator_Fast jmax, j = pn->fast_outs(jmax);

         const Node *cn = pn->fast_out(j);

         if (cn->is_Catch()) {

           ProjNode *cpn = NULL;

           for (DUIterator_Fast kmax, k = cn->fast_outs(kmax); k < kmax; k++) {

             cpn = cn->fast_out(k)->as_Proj();

             assert(cpn->is_CatchProj(), "must be a CatchProjNode");

             if (cpn->_con == CatchProjNode::fall_through_index)

               _fallthroughcatchproj = cpn;

             else {

               assert(cpn->_con == CatchProjNode::catch_all_index, "must be correct index.");

               _catchallcatchproj = cpn;

             }

           }

         }

         break;

       }

       case TypeFunc::I_O:

         if (pn->_is_io_use)

           _ioproj_catchall = pn;

         else

           _ioproj_fallthrough = pn;

         break;

       case TypeFunc::Memory:

         if (pn->_is_io_use)

           _memproj_catchall = pn;

         else

           _memproj_fallthrough = pn;

         break;

       case TypeFunc::Parms:

         _resproj = pn;

         break;

       default:

         assert(false, "unexpected projection from allocation node.");

     }

   }

 }

 // Eliminate a card mark sequence.  p2x is a ConvP2XNode

 void PhaseMacroExpand::eliminate_card_mark(Node* p2x) {

   assert(p2x->Opcode() == Op_CastP2X, "ConvP2XNode required");

   if (!UseG1GC) {

     // vanilla/CMS post barrier

     Node *shift = p2x->unique_out();

     Node *addp = shift->unique_out();

     for (DUIterator_Last jmin, j = addp->last_outs(jmin); j >= jmin; --j) {

       Node *st = addp->last_out(j);

       assert(st->is_Store(), "store required");

       _igvn.replace_node(st, st->in(MemNode::Memory));

     }

   } else {

     // G1 pre/post barriers

     assert(p2x->outcnt() == 2, "expects 2 users: Xor and URShift nodes");

     // It could be only one user, URShift node, in Object.clone() instrinsic

     // but the new allocation is passed to arraycopy stub and it could not

     // be scalar replaced. So we don't check the case.

     // Remove G1 post barrier.

     // Search for CastP2X->Xor->URShift->Cmp path which

     // checks if the store done to a different from the value's region.

     // And replace Cmp with #0 (false) to collapse G1 post barrier.

     Node* xorx = NULL;

     for (DUIterator_Fast imax, i = p2x->fast_outs(imax); i < imax; i++) {

       Node* u = p2x->fast_out(i);

       if (u->Opcode() == Op_XorX) {

         xorx = u;

         break;

       }

     }

     assert(xorx != NULL, "missing G1 post barrier");

     Node* shift = xorx->unique_out();

     Node* cmpx = shift->unique_out();

     assert(cmpx->is_Cmp() && cmpx->unique_out()->is_Bool() &&

     cmpx->unique_out()->as_Bool()->_test._test == BoolTest::ne,

     "missing region check in G1 post barrier");

     _igvn.replace_node(cmpx, makecon(TypeInt::CC_EQ));

     // Remove G1 pre barrier.

     // Search "if (marking != 0)" check and set it to "false".

     Node* this_region = p2x->in(0);

     assert(this_region != NULL, "");

     // There is no G1 pre barrier if previous stored value is NULL

     // (for example, after initialization).

     if (this_region->is_Region() && this_region->req() == 3) {

       int ind = 1;

       if (!this_region->in(ind)->is_IfFalse()) {

         ind = 2;

       }

       if (this_region->in(ind)->is_IfFalse()) {

         Node* bol = this_region->in(ind)->in(0)->in(1);

         assert(bol->is_Bool(), "");

         cmpx = bol->in(1);

         if (bol->as_Bool()->_test._test == BoolTest::ne &&

             cmpx->is_Cmp() && cmpx->in(2) == intcon(0) &&

             cmpx->in(1)->is_Load()) {

           Node* adr = cmpx->in(1)->as_Load()->in(MemNode::Address);

           const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() +

                                               PtrQueue::byte_offset_of_active());

           if (adr->is_AddP() && adr->in(AddPNode::Base) == top() &&

               adr->in(AddPNode::Address)->Opcode() == Op_ThreadLocal &&

               adr->in(AddPNode::Offset) == MakeConX(marking_offset)) {

             _igvn.replace_node(cmpx, makecon(TypeInt::CC_EQ));

           }

         }

       }

     }

     // Now CastP2X can be removed since it is used only on dead path

     // which currently still alive until igvn optimize it.

     assert(p2x->unique_out()->Opcode() == Op_URShiftX, "");

     _igvn.replace_node(p2x, top());

   }

 }

 // Search for a memory operation for the specified memory slice.

 static Node *scan_mem_chain(Node *mem, int alias_idx, int offset, Node *start_mem, Node *alloc, PhaseGVN *phase) {

   Node *orig_mem = mem;

   Node *alloc_mem = alloc->in(TypeFunc::Memory);

   const TypeOopPtr *tinst = phase->C->get_adr_type(alias_idx)->isa_oopptr();

   while (true) {

     if (mem == alloc_mem || mem == start_mem ) {

       return mem;  // hit one of our sentinels

     } else if (mem->is_MergeMem()) {

       mem = mem->as_MergeMem()->memory_at(alias_idx);

     } else if (mem->is_Proj() && mem->as_Proj()->_con == TypeFunc::Memory) {

       Node *in = mem->in(0);

       // we can safely skip over safepoints, calls, locks and membars because we

       // already know that the object is safe to eliminate.

       if (in->is_Initialize() && in->as_Initialize()->allocation() == alloc) {

         return in;

       } else if (in->is_Call()) {

         CallNode *call = in->as_Call();

         if (!call->may_modify(tinst, phase)) {

           mem = call->in(TypeFunc::Memory);

         }

         mem = in->in(TypeFunc::Memory);

       } else if (in->is_MemBar()) {

         mem = in->in(TypeFunc::Memory);

       } else {

         assert(false, "unexpected projection");

       }

     } else if (mem->is_Store()) {

       const TypePtr* atype = mem->as_Store()->adr_type();

       int adr_idx = Compile::current()->get_alias_index(atype);

       if (adr_idx == alias_idx) {

         assert(atype->isa_oopptr(), "address type must be oopptr");

         int adr_offset = atype->offset();

         uint adr_iid = atype->is_oopptr()->instance_id();

         // Array elements references have the same alias_idx

         // but different offset and different instance_id.

         if (adr_offset == offset && adr_iid == alloc->_idx)

           return mem;

       } else {

         assert(adr_idx == Compile::AliasIdxRaw, "address must match or be raw");

       }

       mem = mem->in(MemNode::Memory);

     } else if (mem->is_ClearArray()) {

       if (!ClearArrayNode::step_through(&mem, alloc->_idx, phase)) {

         // Can not bypass initialization of the instance

         // we are looking.

         debug_only(intptr_t offset;)

         assert(alloc == AllocateNode::Ideal_allocation(mem->in(3), phase, offset), "sanity");

         InitializeNode* init = alloc->as_Allocate()->initialization();

         // We are looking for stored value, return Initialize node

         // or memory edge from Allocate node.

         if (init != NULL)

           return init;

         else

           return alloc->in(TypeFunc::Memory); // It will produce zero value (see callers).

       }

       // Otherwise skip it (the call updated 'mem' value).

     } else if (mem->Opcode() == Op_SCMemProj) {

       assert(mem->in(0)->is_LoadStore(), "sanity");

       const TypePtr* atype = mem->in(0)->in(MemNode::Address)->bottom_type()->is_ptr();

       int adr_idx = Compile::current()->get_alias_index(atype);

       if (adr_idx == alias_idx) {

         assert(false, "Object is not scalar replaceable if a LoadStore node access its field");

         return NULL;

       }

       mem = mem->in(0)->in(MemNode::Memory);

     } else {

       return mem;

     }

     assert(mem != orig_mem, "dead memory loop");

   }

 }

 //

 // Given a Memory Phi, compute a value Phi containing the values from stores

 // on the input paths.

 // Note: this function is recursive, its depth is limied by the "level" argument

 // Returns the computed Phi, or NULL if it cannot compute it.

 Node *PhaseMacroExpand::value_from_mem_phi(Node *mem, BasicType ft, const Type *phi_type, const TypeOopPtr *adr_t, Node *alloc, Node_Stack *value_phis, int level) {

   assert(mem->is_Phi(), "sanity");

   int alias_idx = C->get_alias_index(adr_t);

   int offset = adr_t->offset();

   int instance_id = adr_t->instance_id();

   // Check if an appropriate value phi already exists.

   Node* region = mem->in(0);

   for (DUIterator_Fast kmax, k = region->fast_outs(kmax); k < kmax; k++) {

     Node* phi = region->fast_out(k);

     if (phi->is_Phi() && phi != mem &&

         phi->as_Phi()->is_same_inst_field(phi_type, instance_id, alias_idx, offset)) {

       return phi;

     }

   }

   // Check if an appropriate new value phi already exists.

   Node* new_phi = NULL;

   uint size = value_phis->size();

   for (uint i=0; i < size; i++) {

     if ( mem->_idx == value_phis->index_at(i) ) {

       return value_phis->node_at(i);

     }

   }

   if (level <= 0) {

     return NULL; // Give up: phi tree too deep

   }

   Node *start_mem = C->start()->proj_out(TypeFunc::Memory);

   Node *alloc_mem = alloc->in(TypeFunc::Memory);

   uint length = mem->req();

   GrowableArray <Node *> values(length, length, NULL);

   // create a new Phi for the value

   PhiNode *phi = new (C, length) PhiNode(mem->in(0), phi_type, NULL, instance_id, alias_idx, offset);

   transform_later(phi);

   value_phis->push(phi, mem->_idx);

   for (uint j = 1; j < length; j++) {

     Node *in = mem->in(j);

     if (in == NULL || in->is_top()) {

       values.at_put(j, in);

     } else  {

       Node *val = scan_mem_chain(in, alias_idx, offset, start_mem, alloc, &_igvn);

       if (val == start_mem || val == alloc_mem) {

         // hit a sentinel, return appropriate 0 value

         values.at_put(j, _igvn.zerocon(ft));

         continue;

       }

       if (val->is_Initialize()) {

         val = val->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn);

       }

       if (val == NULL) {

         return NULL;  // can't find a value on this path

       }

       if (val == mem) {

         values.at_put(j, mem);

       } else if (val->is_Store()) {

         values.at_put(j, val->in(MemNode::ValueIn));

       } else if(val->is_Proj() && val->in(0) == alloc) {

         values.at_put(j, _igvn.zerocon(ft));

       } else if (val->is_Phi()) {

         val = value_from_mem_phi(val, ft, phi_type, adr_t, alloc, value_phis, level-1);

         if (val == NULL) {

           return NULL;

         }

         values.at_put(j, val);

       } else if (val->Opcode() == Op_SCMemProj) {

         assert(val->in(0)->is_LoadStore(), "sanity");

         assert(false, "Object is not scalar replaceable if a LoadStore node access its field");

         return NULL;

       } else {

 #ifdef ASSERT

         val->dump();

         assert(false, "unknown node on this path");

 #endif

         return NULL;  // unknown node on this path

       }

     }

   }

   // Set Phi's inputs

   for (uint j = 1; j < length; j++) {

     if (values.at(j) == mem) {

       phi->init_req(j, phi);

     } else {

       phi->init_req(j, values.at(j));

     }

   }

   return phi;

 }

 // Search the last value stored into the object's field.

 Node *PhaseMacroExpand::value_from_mem(Node *sfpt_mem, BasicType ft, const Type *ftype, const TypeOopPtr *adr_t, Node *alloc) {

   assert(adr_t->is_known_instance_field(), "instance required");

   int instance_id = adr_t->instance_id();

   assert((uint)instance_id == alloc->_idx, "wrong allocation");

   int alias_idx = C->get_alias_index(adr_t);

   int offset = adr_t->offset();

   Node *start_mem = C->start()->proj_out(TypeFunc::Memory);

   Node *alloc_ctrl = alloc->in(TypeFunc::Control);

   Node *alloc_mem = alloc->in(TypeFunc::Memory);

   Arena *a = Thread::current()->resource_area();

   VectorSet visited(a);

   bool done = sfpt_mem == alloc_mem;

   Node *mem = sfpt_mem;

   while (!done) {

     if (visited.test_set(mem->_idx)) {

       return NULL;  // found a loop, give up

     }

     mem = scan_mem_chain(mem, alias_idx, offset, start_mem, alloc, &_igvn);

     if (mem == start_mem || mem == alloc_mem) {

       done = true;  // hit a sentinel, return appropriate 0 value

     } else if (mem->is_Initialize()) {

       mem = mem->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn);

       if (mem == NULL) {

         done = true; // Something go wrong.

       } else if (mem->is_Store()) {

         const TypePtr* atype = mem->as_Store()->adr_type();

         assert(C->get_alias_index(atype) == Compile::AliasIdxRaw, "store is correct memory slice");

         done = true;

       }

     } else if (mem->is_Store()) {

       const TypeOopPtr* atype = mem->as_Store()->adr_type()->isa_oopptr();

       assert(atype != NULL, "address type must be oopptr");

       assert(C->get_alias_index(atype) == alias_idx &&

              atype->is_known_instance_field() && atype->offset() == offset &&

              atype->instance_id() == instance_id, "store is correct memory slice");

       done = true;

     } else if (mem->is_Phi()) {

       // try to find a phi's unique input

       Node *unique_input = NULL;

       Node *top = C->top();

       for (uint i = 1; i < mem->req(); i++) {

         Node *n = scan_mem_chain(mem->in(i), alias_idx, offset, start_mem, alloc, &_igvn);

         if (n == NULL || n == top || n == mem) {

           continue;

         } else if (unique_input == NULL) {

           unique_input = n;

         } else if (unique_input != n) {

           unique_input = top;

           break;

         }

       }

       if (unique_input != NULL && unique_input != top) {

         mem = unique_input;

       } else {

         done = true;

       }

     } else {

       assert(false, "unexpected node");

     }

   }

   if (mem != NULL) {

     if (mem == start_mem || mem == alloc_mem) {

       // hit a sentinel, return appropriate 0 value

       return _igvn.zerocon(ft);

     } else if (mem->is_Store()) {

       return mem->in(MemNode::ValueIn);

     } else if (mem->is_Phi()) {

       // attempt to produce a Phi reflecting the values on the input paths of the Phi

       Node_Stack value_phis(a, 8);

       Node * phi = value_from_mem_phi(mem, ft, ftype, adr_t, alloc, &value_phis, ValueSearchLimit);

       if (phi != NULL) {

         return phi;

       } else {

         // Kill all new Phis

         while(value_phis.is_nonempty()) {

           Node* n = value_phis.node();

           _igvn.replace_node(n, C->top());

           value_phis.pop();

         }

       }

     }

   }

   // Something go wrong.

   return NULL;

 }

 // Check the possibility of scalar replacement.

 bool PhaseMacroExpand::can_eliminate_allocation(AllocateNode *alloc, GrowableArray <SafePointNode *>& safepoints) {

   //  Scan the uses of the allocation to check for anything that would

   //  prevent us from eliminating it.

   NOT_PRODUCT( const char* fail_eliminate = NULL; )

   DEBUG_ONLY( Node* disq_node = NULL; )

   bool  can_eliminate = true;

   Node* res = alloc->result_cast();

   const TypeOopPtr* res_type = NULL;

   if (res == NULL) {

     // All users were eliminated.

   } else if (!res->is_CheckCastPP()) {

     alloc->_is_scalar_replaceable = false;  // don't try again

     NOT_PRODUCT(fail_eliminate = "Allocation does not have unique CheckCastPP";)

     can_eliminate = false;

   } else {

     res_type = _igvn.type(res)->isa_oopptr();

     if (res_type == NULL) {

       NOT_PRODUCT(fail_eliminate = "Neither instance or array allocation";)

       can_eliminate = false;

     } else if (res_type->isa_aryptr()) {

       int length = alloc->in(AllocateNode::ALength)->find_int_con(-1);

       if (length < 0) {

         NOT_PRODUCT(fail_eliminate = "Array's size is not constant";)

         can_eliminate = false;

       }

     }

   }

   if (can_eliminate && res != NULL) {

     for (DUIterator_Fast jmax, j = res->fast_outs(jmax);

                                j < jmax && can_eliminate; j++) {

       Node* use = res->fast_out(j);

       if (use->is_AddP()) {

         const TypePtr* addp_type = _igvn.type(use)->is_ptr();

         int offset = addp_type->offset();

         if (offset == Type::OffsetTop || offset == Type::OffsetBot) {

           NOT_PRODUCT(fail_eliminate = "Undefined field referrence";)

           can_eliminate = false;

           break;

         }

         for (DUIterator_Fast kmax, k = use->fast_outs(kmax);

                                    k < kmax && can_eliminate; k++) {

           Node* n = use->fast_out(k);

           if (!n->is_Store() && n->Opcode() != Op_CastP2X) {

             DEBUG_ONLY(disq_node = n;)

             if (n->is_Load() || n->is_LoadStore()) {

               NOT_PRODUCT(fail_eliminate = "Field load";)

             } else {

               NOT_PRODUCT(fail_eliminate = "Not store field referrence";)

             }

             can_eliminate = false;

           }

         }

       } else if (use->is_SafePoint()) {

         SafePointNode* sfpt = use->as_SafePoint();

         if (sfpt->is_Call() && sfpt->as_Call()->has_non_debug_use(res)) {

           // Object is passed as argument.

           DEBUG_ONLY(disq_node = use;)

           NOT_PRODUCT(fail_eliminate = "Object is passed as argument";)

           can_eliminate = false;

         }

         Node* sfptMem = sfpt->memory();

         if (sfptMem == NULL || sfptMem->is_top()) {

           DEBUG_ONLY(disq_node = use;)

           NOT_PRODUCT(fail_eliminate = "NULL or TOP memory";)

           can_eliminate = false;

         } else {

           safepoints.append_if_missing(sfpt);

         }

       } else if (use->Opcode() != Op_CastP2X) { // CastP2X is used by card mark

         if (use->is_Phi()) {

           if (use->outcnt() == 1 && use->unique_out()->Opcode() == Op_Return) {

             NOT_PRODUCT(fail_eliminate = "Object is return value";)

           } else {

             NOT_PRODUCT(fail_eliminate = "Object is referenced by Phi";)

           }

           DEBUG_ONLY(disq_node = use;)

         } else {

           if (use->Opcode() == Op_Return) {

             NOT_PRODUCT(fail_eliminate = "Object is return value";)

           }else {

             NOT_PRODUCT(fail_eliminate = "Object is referenced by node";)

           }

           DEBUG_ONLY(disq_node = use;)

         }

         can_eliminate = false;

       }

     }

   }

 #ifndef PRODUCT

   if (PrintEliminateAllocations) {

     if (can_eliminate) {

       tty->print("Scalar ");

       if (res == NULL)

         alloc->dump();

       else

         res->dump();

     } else {

       tty->print("NotScalar (%s)", fail_eliminate);

       if (res == NULL)

         alloc->dump();

       else

         res->dump();

 #ifdef ASSERT

       if (disq_node != NULL) {

           tty->print("  >>>> ");

           disq_node->dump();

       }

 #endif /*ASSERT*/

     }

   }

 #endif

   return can_eliminate;

 }

 // Do scalar replacement.

 bool PhaseMacroExpand::scalar_replacement(AllocateNode *alloc, GrowableArray <SafePointNode *>& safepoints) {

   GrowableArray <SafePointNode *> safepoints_done;

   ciKlass* klass = NULL;

   ciInstanceKlass* iklass = NULL;

   int nfields = 0;

   int array_base;

   int element_size;

   BasicType basic_elem_type;

   ciType* elem_type;

   Node* res = alloc->result_cast();

   const TypeOopPtr* res_type = NULL;

   if (res != NULL) { // Could be NULL when there are no users

     res_type = _igvn.type(res)->isa_oopptr();

   }

   if (res != NULL) {

     klass = res_type->klass();

     if (res_type->isa_instptr()) {

       // find the fields of the class which will be needed for safepoint debug information

       assert(klass->is_instance_klass(), "must be an instance klass.");

       iklass = klass->as_instance_klass();

       nfields = iklass->nof_nonstatic_fields();

     } else {

       // find the array's elements which will be needed for safepoint debug information

       nfields = alloc->in(AllocateNode::ALength)->find_int_con(-1);

       assert(klass->is_array_klass() && nfields >= 0, "must be an array klass.");

       elem_type = klass->as_array_klass()->element_type();

       basic_elem_type = elem_type->basic_type();

       array_base = arrayOopDesc::base_offset_in_bytes(basic_elem_type);

       element_size = type2aelembytes(basic_elem_type);

     }

   }

   //

   // Process the safepoint uses

   //

   while (safepoints.length() > 0) {

     SafePointNode* sfpt = safepoints.pop();

     Node* mem = sfpt->memory();

     uint first_ind = sfpt->req();

     SafePointScalarObjectNode* sobj = new (C, 1) SafePointScalarObjectNode(res_type,

 #ifdef ASSERT

                                                  alloc,

 #endif

                                                  first_ind, nfields);

     sobj->init_req(0, sfpt->in(TypeFunc::Control));

     transform_later(sobj);

     // Scan object's fields adding an input to the safepoint for each field.

     for (int j = 0; j < nfields; j++) {

       intptr_t offset;

       ciField* field = NULL;

       if (iklass != NULL) {

         field = iklass->nonstatic_field_at(j);

         offset = field->offset();

         elem_type = field->type();

         basic_elem_type = field->layout_type();

       } else {

         offset = array_base + j * (intptr_t)element_size;

       }

       const Type *field_type;

       // The next code is taken from Parse::do_get_xxx().

       if (basic_elem_type == T_OBJECT || basic_elem_type == T_ARRAY) {

         if (!elem_type->is_loaded()) {

           field_type = TypeInstPtr::BOTTOM;

         } else if (field != NULL && field->is_constant() && field->is_static()) {

           // This can happen if the constant oop is non-perm.

           ciObject* con = field->constant_value().as_object();

           // Do not "join" in the previous type; it doesn't add value,

           // and may yield a vacuous result if the field is of interface type.

           field_type = TypeOopPtr::make_from_constant(con)->isa_oopptr();

           assert(field_type != NULL, "field singleton type must be consistent");

         } else {

           field_type = TypeOopPtr::make_from_klass(elem_type->as_klass());

         }

         if (UseCompressedOops) {

           field_type = field_type->make_narrowoop();

           basic_elem_type = T_NARROWOOP;

         }

       } else {

         field_type = Type::get_const_basic_type(basic_elem_type);

       }

       const TypeOopPtr *field_addr_type = res_type->add_offset(offset)->isa_oopptr();

       Node *field_val = value_from_mem(mem, basic_elem_type, field_type, field_addr_type, alloc);

       if (field_val == NULL) {

         // we weren't able to find a value for this field,

         // give up on eliminating this allocation

         alloc->_is_scalar_replaceable = false;  // don't try again

         // remove any extra entries we added to the safepoint

         uint last = sfpt->req() - 1;

         for (int k = 0;  k < j; k++) {

           sfpt->del_req(last--);

         }

         // rollback processed safepoints

         while (safepoints_done.length() > 0) {

           SafePointNode* sfpt_done = safepoints_done.pop();

           // remove any extra entries we added to the safepoint

           last = sfpt_done->req() - 1;

           for (int k = 0;  k < nfields; k++) {

             sfpt_done->del_req(last--);

           }

           JVMState *jvms = sfpt_done->jvms();

           jvms->set_endoff(sfpt_done->req());

           // Now make a pass over the debug information replacing any references

           // to SafePointScalarObjectNode with the allocated object.

           int start = jvms->debug_start();

           int end   = jvms->debug_end();

           for (int i = start; i < end; i++) {

             if (sfpt_done->in(i)->is_SafePointScalarObject()) {

               SafePointScalarObjectNode* scobj = sfpt_done->in(i)->as_SafePointScalarObject();

               if (scobj->first_index() == sfpt_done->req() &&

                   scobj->n_fields() == (uint)nfields) {

                 assert(scobj->alloc() == alloc, "sanity");

                 sfpt_done->set_req(i, res);

               }

             }

           }

         }

 #ifndef PRODUCT

         if (PrintEliminateAllocations) {

           if (field != NULL) {

             tty->print("=== At SafePoint node %d can't find value of Field: ",

                        sfpt->_idx);

             field->print();

             int field_idx = C->get_alias_index(field_addr_type);

             tty->print(" (alias_idx=%d)", field_idx);

           } else { // Array's element

             tty->print("=== At SafePoint node %d can't find value of array element [%d]",

                        sfpt->_idx, j);

           }

           tty->print(", which prevents elimination of: ");

           if (res == NULL)

             alloc->dump();

           else

             res->dump();

         }

 #endif

         return false;

       }

       if (UseCompressedOops && field_type->isa_narrowoop()) {

         // Enable "DecodeN(EncodeP(Allocate)) --> Allocate" transformation

         // to be able scalar replace the allocation.

         if (field_val->is_EncodeP()) {

           field_val = field_val->in(1);

         } else {

           field_val = transform_later(new (C, 2) DecodeNNode(field_val, field_val->bottom_type()->make_ptr()));

         }

       }

       sfpt->add_req(field_val);

     }

     JVMState *jvms = sfpt->jvms();

     jvms->set_endoff(sfpt->req());

     // Now make a pass over the debug information replacing any references

     // to the allocated object with "sobj"

     int start = jvms->debug_start();

     int end   = jvms->debug_end();

     for (int i = start; i < end; i++) {

       if (sfpt->in(i) == res) {

         sfpt->set_req(i, sobj);

       }

     }

     safepoints_done.append_if_missing(sfpt); // keep it for rollback

   }

   return true;

 }

 // Process users of eliminated allocation.

 void PhaseMacroExpand::process_users_of_allocation(AllocateNode *alloc) {

   Node* res = alloc->result_cast();

   if (res != NULL) {

     for (DUIterator_Last jmin, j = res->last_outs(jmin); j >= jmin; ) {

       Node *use = res->last_out(j);

       uint oc1 = res->outcnt();

       if (use->is_AddP()) {

         for (DUIterator_Last kmin, k = use->last_outs(kmin); k >= kmin; ) {

           Node *n = use->last_out(k);

           uint oc2 = use->outcnt();

           if (n->is_Store()) {

 #ifdef ASSERT

             // Verify that there is no dependent MemBarVolatile nodes,

             // they should be removed during IGVN, see MemBarNode::Ideal().

             for (DUIterator_Fast pmax, p = n->fast_outs(pmax);

                                        p < pmax; p++) {

               Node* mb = n->fast_out(p);

               assert(mb->is_Initialize() || !mb->is_MemBar() ||

                      mb->req() <= MemBarNode::Precedent ||

                      mb->in(MemBarNode::Precedent) != n,

                      "MemBarVolatile should be eliminated for non-escaping object");

             }

 #endif

             _igvn.replace_node(n, n->in(MemNode::Memory));

           } else {

             eliminate_card_mark(n);

           }

           k -= (oc2 - use->outcnt());

         }

       } else {

         eliminate_card_mark(use);

       }

       j -= (oc1 - res->outcnt());

     }

     assert(res->outcnt() == 0, "all uses of allocated objects must be deleted");

     _igvn.remove_dead_node(res);

   }

   //

   // Process other users of allocation's projections

   //

   if (_resproj != NULL && _resproj->outcnt() != 0) {

     for (DUIterator_Last jmin, j = _resproj->last_outs(jmin); j >= jmin; ) {

       Node *use = _resproj->last_out(j);

       uint oc1 = _resproj->outcnt();

       if (use->is_Initialize()) {

         // Eliminate Initialize node.

         InitializeNode *init = use->as_Initialize();

         assert(init->outcnt() <= 2, "only a control and memory projection expected");

         Node *ctrl_proj = init->proj_out(TypeFunc::Control);

         if (ctrl_proj != NULL) {

            assert(init->in(TypeFunc::Control) == _fallthroughcatchproj, "allocation control projection");

           _igvn.replace_node(ctrl_proj, _fallthroughcatchproj);

         }

         Node *mem_proj = init->proj_out(TypeFunc::Memory);

         if (mem_proj != NULL) {

           Node *mem = init->in(TypeFunc::Memory);

 #ifdef ASSERT

           if (mem->is_MergeMem()) {

             assert(mem->in(TypeFunc::Memory) == _memproj_fallthrough, "allocation memory projection");

           } else {

             assert(mem == _memproj_fallthrough, "allocation memory projection");

           }

 #endif

           _igvn.replace_node(mem_proj, mem);

         }

       } else if (use->is_AddP()) {

         // raw memory addresses used only by the initialization

         _igvn.replace_node(use, C->top());

       } else  {

         assert(false, "only Initialize or AddP expected");

       }

       j -= (oc1 - _resproj->outcnt());

     }

   }

   if (_fallthroughcatchproj != NULL) {

     _igvn.replace_node(_fallthroughcatchproj, alloc->in(TypeFunc::Control));

   }

   if (_memproj_fallthrough != NULL) {

     _igvn.replace_node(_memproj_fallthrough, alloc->in(TypeFunc::Memory));

   }

   if (_memproj_catchall != NULL) {

     _igvn.replace_node(_memproj_catchall, C->top());

   }

   if (_ioproj_fallthrough != NULL) {

     _igvn.replace_node(_ioproj_fallthrough, alloc->in(TypeFunc::I_O));

   }

   if (_ioproj_catchall != NULL) {

     _igvn.replace_node(_ioproj_catchall, C->top());

   }

   if (_catchallcatchproj != NULL) {

     _igvn.replace_node(_catchallcatchproj, C->top());

   }

 }

 bool PhaseMacroExpand::eliminate_allocate_node(AllocateNode *alloc) {

   if (!EliminateAllocations || !alloc->_is_scalar_replaceable) {

     return false;

   }

   extract_call_projections(alloc);

   GrowableArray <SafePointNode *> safepoints;

   if (!can_eliminate_allocation(alloc, safepoints)) {

     return false;

   }

   if (!scalar_replacement(alloc, safepoints)) {

     return false;

   }

   CompileLog* log = C->log();

   if (log != NULL) {

     Node* klass = alloc->in(AllocateNode::KlassNode);

     const TypeKlassPtr* tklass = _igvn.type(klass)->is_klassptr();

     log->head("eliminate_allocation type='%d'",

               log->identify(tklass->klass()));

     JVMState* p = alloc->jvms();

     while (p != NULL) {

       log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));

       p = p->caller();

     }

     log->tail("eliminate_allocation");

   }

   process_users_of_allocation(alloc);

 #ifndef PRODUCT

   if (PrintEliminateAllocations) {

     if (alloc->is_AllocateArray())

       tty->print_cr("++++ Eliminated: %d AllocateArray", alloc->_idx);

     else

       tty->print_cr("++++ Eliminated: %d Allocate", alloc->_idx);

   }

 #endif

   return true;

 }

 //---------------------------set_eden_pointers-------------------------

 void PhaseMacroExpand::set_eden_pointers(Node* &eden_top_adr, Node* &eden_end_adr) {

   if (UseTLAB) {                // Private allocation: load from TLS

     Node* thread = transform_later(new (C, 1) ThreadLocalNode());

     int tlab_top_offset = in_bytes(JavaThread::tlab_top_offset());

     int tlab_end_offset = in_bytes(JavaThread::tlab_end_offset());

     eden_top_adr = basic_plus_adr(top()/*not oop*/, thread, tlab_top_offset);

     eden_end_adr = basic_plus_adr(top()/*not oop*/, thread, tlab_end_offset);

   } else {                      // Shared allocation: load from globals

     CollectedHeap* ch = Universe::heap();

     address top_adr = (address)ch->top_addr();

     address end_adr = (address)ch->end_addr();

     eden_top_adr = makecon(TypeRawPtr::make(top_adr));

     eden_end_adr = basic_plus_adr(eden_top_adr, end_adr - top_adr);

   }

 }

 Node* PhaseMacroExpand::make_load(Node* ctl, Node* mem, Node* base, int offset, const Type* value_type, BasicType bt) {

   Node* adr = basic_plus_adr(base, offset);

   const TypePtr* adr_type = adr->bottom_type()->is_ptr();

   Node* value = LoadNode::make(_igvn, ctl, mem, adr, adr_type, value_type, bt);

   transform_later(value);

   return value;

 }

 Node* PhaseMacroExpand::make_store(Node* ctl, Node* mem, Node* base, int offset, Node* value, BasicType bt) {

   Node* adr = basic_plus_adr(base, offset);

   mem = StoreNode::make(_igvn, ctl, mem, adr, NULL, value, bt);

   transform_later(mem);

   return mem;

 }

 //=============================================================================

 //

 //                              A L L O C A T I O N

 //

 // Allocation attempts to be fast in the case of frequent small objects.

 // It breaks down like this:

 //

 // 1) Size in doublewords is computed.  This is a constant for objects and

 // variable for most arrays.  Doubleword units are used to avoid size

 // overflow of huge doubleword arrays.  We need doublewords in the end for

 // rounding.

 //

 // 2) Size is checked for being 'too large'.  Too-large allocations will go

 // the slow path into the VM.  The slow path can throw any required

 // exceptions, and does all the special checks for very large arrays.  The

 // size test can constant-fold away for objects.  For objects with

 // finalizers it constant-folds the otherway: you always go slow with

 // finalizers.

 //

 // 3) If NOT using TLABs, this is the contended loop-back point.

 // Load-Locked the heap top.  If using TLABs normal-load the heap top.

 //

 // 4) Check that heap top + size*8 < max.  If we fail go the slow ` route.

 // NOTE: "top+size*8" cannot wrap the 4Gig line!  Here's why: for largish

 // "size*8" we always enter the VM, where "largish" is a constant picked small

 // enough that there's always space between the eden max and 4Gig (old space is

 // there so it's quite large) and large enough that the cost of entering the VM

 // is dwarfed by the cost to initialize the space.

 //

 // 5) If NOT using TLABs, Store-Conditional the adjusted heap top back

 // down.  If contended, repeat at step 3.  If using TLABs normal-store

 // adjusted heap top back down; there is no contention.

 //

 // 6) If !ZeroTLAB then Bulk-clear the object/array.  Fill in klass & mark

 // fields.

 //

 // 7) Merge with the slow-path; cast the raw memory pointer to the correct

 // oop flavor.

 //

 //=============================================================================

 // FastAllocateSizeLimit value is in DOUBLEWORDS.

 // Allocations bigger than this always go the slow route.

 // This value must be small enough that allocation attempts that need to

 // trigger exceptions go the slow route.  Also, it must be small enough so

 // that heap_top + size_in_bytes does not wrap around the 4Gig limit.

 //=============================================================================j//

 // %%% Here is an old comment from parseHelper.cpp; is it outdated?

 // The allocator will coalesce int->oop copies away.  See comment in

 // coalesce.cpp about how this works.  It depends critically on the exact

 // code shape produced here, so if you are changing this code shape

 // make sure the GC info for the heap-top is correct in and around the

 // slow-path call.

 //

 void PhaseMacroExpand::expand_allocate_common(

             AllocateNode* alloc, // allocation node to be expanded

             Node* length,  // array length for an array allocation

             const TypeFunc* slow_call_type, // Type of slow call

             address slow_call_address  // Address of slow call

     )

 {

   Node* ctrl = alloc->in(TypeFunc::Control);

   Node* mem  = alloc->in(TypeFunc::Memory);

   Node* i_o  = alloc->in(TypeFunc::I_O);

   Node* size_in_bytes     = alloc->in(AllocateNode::AllocSize);

   Node* klass_node        = alloc->in(AllocateNode::KlassNode);

   Node* initial_slow_test = alloc->in(AllocateNode::InitialTest);

   assert(ctrl != NULL, "must have control");

   // We need a Region and corresponding Phi's to merge the slow-path and fast-path results.

   // they will not be used if "always_slow" is set

   enum { slow_result_path = 1, fast_result_path = 2 };

   Node *result_region;

   Node *result_phi_rawmem;

   Node *result_phi_rawoop;

   Node *result_phi_i_o;

   // The initial slow comparison is a size check, the comparison

   // we want to do is a BoolTest::gt

   bool always_slow = false;

   int tv = _igvn.find_int_con(initial_slow_test, -1);

   if (tv >= 0) {

     always_slow = (tv == 1);

     initial_slow_test = NULL;

   } else {

     initial_slow_test = BoolNode::make_predicate(initial_slow_test, &_igvn);

   }

   if (C->env()->dtrace_alloc_probes() ||

       !UseTLAB && (!Universe::heap()->supports_inline_contig_alloc() ||

                    (UseConcMarkSweepGC && CMSIncrementalMode))) {

     // Force slow-path allocation

     always_slow = true;

     initial_slow_test = NULL;

   }

   enum { too_big_or_final_path = 1, need_gc_path = 2 };

   Node *slow_region = NULL;

   Node *toobig_false = ctrl;

   assert (initial_slow_test == NULL || !always_slow, "arguments must be consistent");

   // generate the initial test if necessary

   if (initial_slow_test != NULL ) {

     slow_region = new (C, 3) RegionNode(3);

     // Now make the initial failure test.  Usually a too-big test but

     // might be a TRUE for finalizers or a fancy class check for

     // newInstance0.

     IfNode *toobig_iff = new (C, 2) IfNode(ctrl, initial_slow_test, PROB_MIN, COUNT_UNKNOWN);

     transform_later(toobig_iff);

     // Plug the failing-too-big test into the slow-path region

     Node *toobig_true = new (C, 1) IfTrueNode( toobig_iff );

     transform_later(toobig_true);

     slow_region    ->init_req( too_big_or_final_path, toobig_true );

     toobig_false = new (C, 1) IfFalseNode( toobig_iff );

     transform_later(toobig_false);

   } else {         // No initial test, just fall into next case

     toobig_false = ctrl;

     debug_only(slow_region = NodeSentinel);

   }

   Node *slow_mem = mem;  // save the current memory state for slow path

   // generate the fast allocation code unless we know that the initial test will always go slow

   if (!always_slow) {

     // Fast path modifies only raw memory.

     if (mem->is_MergeMem()) {

       mem = mem->as_MergeMem()->memory_at(Compile::AliasIdxRaw);

     }

     Node* eden_top_adr;

     Node* eden_end_adr;

     set_eden_pointers(eden_top_adr, eden_end_adr);

     // Load Eden::end.  Loop invariant and hoisted.

     //

     // Note: We set the control input on "eden_end" and "old_eden_top" when using

     //       a TLAB to work around a bug where these values were being moved across

     //       a safepoint.  These are not oops, so they cannot be include in the oop

     //       map, but the can be changed by a GC.   The proper way to fix this would

     //       be to set the raw memory state when generating a  SafepointNode.  However

     //       this will require extensive changes to the loop optimization in order to

     //       prevent a degradation of the optimization.

     //       See comment in memnode.hpp, around line 227 in class LoadPNode.

     Node *eden_end = make_load(ctrl, mem, eden_end_adr, 0, TypeRawPtr::BOTTOM, T_ADDRESS);

     // allocate the Region and Phi nodes for the result

     result_region = new (C, 3) RegionNode(3);

     result_phi_rawmem = new (C, 3) PhiNode( result_region, Type::MEMORY, TypeRawPtr::BOTTOM );

     result_phi_rawoop = new (C, 3) PhiNode( result_region, TypeRawPtr::BOTTOM );

     result_phi_i_o    = new (C, 3) PhiNode( result_region, Type::ABIO ); // I/O is used for Prefetch

     // We need a Region for the loop-back contended case.

     enum { fall_in_path = 1, contended_loopback_path = 2 };

     Node *contended_region;

     Node *contended_phi_rawmem;

     if( UseTLAB ) {

       contended_region = toobig_false;

       contended_phi_rawmem = mem;

     } else {

       contended_region = new (C, 3) RegionNode(3);

       contended_phi_rawmem = new (C, 3) PhiNode( contended_region, Type::MEMORY, TypeRawPtr::BOTTOM);

       // Now handle the passing-too-big test.  We fall into the contended

       // loop-back merge point.

       contended_region    ->init_req( fall_in_path, toobig_false );

       contended_phi_rawmem->init_req( fall_in_path, mem );

       transform_later(contended_region);

       transform_later(contended_phi_rawmem);

     }

     // Load(-locked) the heap top.

     // See note above concerning the control input when using a TLAB

     Node *old_eden_top = UseTLAB

       ? new (C, 3) LoadPNode     ( ctrl, contended_phi_rawmem, eden_top_adr, TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM )

       : new (C, 3) LoadPLockedNode( contended_region, contended_phi_rawmem, eden_top_adr );

     transform_later(old_eden_top);

     // Add to heap top to get a new heap top

     Node *new_eden_top = new (C, 4) AddPNode( top(), old_eden_top, size_in_bytes );

     transform_later(new_eden_top);

     // Check for needing a GC; compare against heap end

     Node *needgc_cmp = new (C, 3) CmpPNode( new_eden_top, eden_end );

     transform_later(needgc_cmp);

     Node *needgc_bol = new (C, 2) BoolNode( needgc_cmp, BoolTest::ge );

     transform_later(needgc_bol);

     IfNode *needgc_iff = new (C, 2) IfNode(contended_region, needgc_bol, PROB_UNLIKELY_MAG(4), COUNT_UNKNOWN );

     transform_later(needgc_iff);

     // Plug the failing-heap-space-need-gc test into the slow-path region

     Node *needgc_true = new (C, 1) IfTrueNode( needgc_iff );

     transform_later(needgc_true);

     if( initial_slow_test ) {

       slow_region    ->init_req( need_gc_path, needgc_true );

       // This completes all paths into the slow merge point

       transform_later(slow_region);

     } else {                      // No initial slow path needed!

       // Just fall from the need-GC path straight into the VM call.

       slow_region    = needgc_true;

     }

     // No need for a GC.  Setup for the Store-Conditional

     Node *needgc_false = new (C, 1) IfFalseNode( needgc_iff );

     transform_later(needgc_false);

     // Grab regular I/O before optional prefetch may change it.

     // Slow-path does no I/O so just set it to the original I/O.

     result_phi_i_o->init_req( slow_result_path, i_o );

     i_o = prefetch_allocation(i_o, needgc_false, contended_phi_rawmem,

                               old_eden_top, new_eden_top, length);

     // Store (-conditional) the modified eden top back down.

     // StorePConditional produces flags for a test PLUS a modified raw

     // memory state.

     Node *store_eden_top;

     Node *fast_oop_ctrl;

     if( UseTLAB ) {

       store_eden_top = new (C, 4) StorePNode( needgc_false, contended_phi_rawmem, eden_top_adr, TypeRawPtr::BOTTOM, new_eden_top );

       transform_later(store_eden_top);

       fast_oop_ctrl = needgc_false; // No contention, so this is the fast path

     } else {

       store_eden_top = new (C, 5) StorePConditionalNode( needgc_false, contended_phi_rawmem, eden_top_adr, new_eden_top, old_eden_top );

       transform_later(store_eden_top);

       Node *contention_check = new (C, 2) BoolNode( store_eden_top, BoolTest::ne );

       transform_later(contention_check);

       store_eden_top = new (C, 1) SCMemProjNode(store_eden_top);

       transform_later(store_eden_top);

       // If not using TLABs, check to see if there was contention.

       IfNode *contention_iff = new (C, 2) IfNode ( needgc_false, contention_check, PROB_MIN, COUNT_UNKNOWN );

       transform_later(contention_iff);

       Node *contention_true = new (C, 1) IfTrueNode( contention_iff );

       transform_later(contention_true);

       // If contention, loopback and try again.

       contended_region->init_req( contended_loopback_path, contention_true );

       contended_phi_rawmem->init_req( contended_loopback_path, store_eden_top );

       // Fast-path succeeded with no contention!

       Node *contention_false = new (C, 1) IfFalseNode( contention_iff );

       transform_later(contention_false);

       fast_oop_ctrl = contention_false;

     }

     // Rename successful fast-path variables to make meaning more obvious

     Node* fast_oop        = old_eden_top;

     Node* fast_oop_rawmem = store_eden_top;

     fast_oop_rawmem = initialize_object(alloc,

                                         fast_oop_ctrl, fast_oop_rawmem, fast_oop,

                                         klass_node, length, size_in_bytes);

     if (C->env()->dtrace_extended_probes()) {

       // Slow-path call

       int size = TypeFunc::Parms + 2;

       CallLeafNode *call = new (C, size) CallLeafNode(OptoRuntime::dtrace_object_alloc_Type(),

                                                       CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_object_alloc_base),

                                                       "dtrace_object_alloc",

                                                       TypeRawPtr::BOTTOM);

       // Get base of thread-local storage area

       Node* thread = new (C, 1) ThreadLocalNode();

       transform_later(thread);

       call->init_req(TypeFunc::Parms+0, thread);

       call->init_req(TypeFunc::Parms+1, fast_oop);

       call->init_req( TypeFunc::Control, fast_oop_ctrl );

       call->init_req( TypeFunc::I_O    , top() )        ;   // does no i/o

       call->init_req( TypeFunc::Memory , fast_oop_rawmem );

       call->init_req( TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr) );

       call->init_req( TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr) );

       transform_later(call);

       fast_oop_ctrl = new (C, 1) ProjNode(call,TypeFunc::Control);

       transform_later(fast_oop_ctrl);

       fast_oop_rawmem = new (C, 1) ProjNode(call,TypeFunc::Memory);

       transform_later(fast_oop_rawmem);

     }

     // Plug in the successful fast-path into the result merge point

     result_region    ->init_req( fast_result_path, fast_oop_ctrl );

     result_phi_rawoop->init_req( fast_result_path, fast_oop );

     result_phi_i_o   ->init_req( fast_result_path, i_o );

     result_phi_rawmem->init_req( fast_result_path, fast_oop_rawmem );

   } else {

     slow_region = ctrl;

   }

   // Generate slow-path call

   CallNode *call = new (C, slow_call_type->domain()->cnt())

     CallStaticJavaNode(slow_call_type, slow_call_address,

                        OptoRuntime::stub_name(slow_call_address),

                        alloc->jvms()->bci(),

                        TypePtr::BOTTOM);

   call->init_req( TypeFunc::Control, slow_region );

   call->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o

   call->init_req( TypeFunc::Memory , slow_mem ); // may gc ptrs

   call->init_req( TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr) );

   call->init_req( TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr) );

   call->init_req(TypeFunc::Parms+0, klass_node);

   if (length != NULL) {

     call->init_req(TypeFunc::Parms+1, length);

   }

   // Copy debug information and adjust JVMState information, then replace

   // allocate node with the call

   copy_call_debug_info((CallNode *) alloc,  call);

   if (!always_slow) {

     call->set_cnt(PROB_UNLIKELY_MAG(4));  // Same effect as RC_UNCOMMON.

   }

   _igvn.replace_node(alloc, call);

   transform_later(call);

   // Identify the output projections from the allocate node and

   // adjust any references to them.

   // The control and io projections look like:

   //

   //        v---Proj(ctrl) <-----+   v---CatchProj(ctrl)

   //  Allocate                   Catch

   //        ^---Proj(io) <-------+   ^---CatchProj(io)

   //

   //  We are interested in the CatchProj nodes.

   //

   extract_call_projections(call);

   // An allocate node has separate memory projections for the uses on the control and i_o paths

   // Replace uses of the control memory projection with result_phi_rawmem (unless we are only generating a slow call)

   if (!always_slow && _memproj_fallthrough != NULL) {

     for (DUIterator_Fast imax, i = _memproj_fallthrough->fast_outs(imax); i < imax; i++) {

       Node *use = _memproj_fallthrough->fast_out(i);

       _igvn.hash_delete(use);

       imax -= replace_input(use, _memproj_fallthrough, result_phi_rawmem);

       _igvn._worklist.push(use);

       // back up iterator

       --i;

     }

   }

   // Now change uses of _memproj_catchall to use _memproj_fallthrough and delete _memproj_catchall so

   // we end up with a call that has only 1 memory projection

   if (_memproj_catchall != NULL ) {

     if (_memproj_fallthrough == NULL) {

       _memproj_fallthrough = new (C, 1) ProjNode(call, TypeFunc::Memory);

       transform_later(_memproj_fallthrough);

     }

     for (DUIterator_Fast imax, i = _memproj_catchall->fast_outs(imax); i < imax; i++) {

       Node *use = _memproj_catchall->fast_out(i);

       _igvn.hash_delete(use);

       imax -= replace_input(use, _memproj_catchall, _memproj_fallthrough);

       _igvn._worklist.push(use);

       // back up iterator

       --i;

     }

   }

   // An allocate node has separate i_o projections for the uses on the control and i_o paths

   // Replace uses of the control i_o projection with result_phi_i_o (unless we are only generating a slow call)

   if (_ioproj_fallthrough == NULL) {

     _ioproj_fallthrough = new (C, 1) ProjNode(call, TypeFunc::I_O);

     transform_later(_ioproj_fallthrough);

   } else if (!always_slow) {

     for (DUIterator_Fast imax, i = _ioproj_fallthrough->fast_outs(imax); i < imax; i++) {

       Node *use = _ioproj_fallthrough->fast_out(i);

       _igvn.hash_delete(use);

       imax -= replace_input(use, _ioproj_fallthrough, result_phi_i_o);

       _igvn._worklist.push(use);

       // back up iterator

       --i;

     }

   }

   // Now change uses of _ioproj_catchall to use _ioproj_fallthrough and delete _ioproj_catchall so

   // we end up with a call that has only 1 control projection

   if (_ioproj_catchall != NULL ) {

     for (DUIterator_Fast imax, i = _ioproj_catchall->fast_outs(imax); i < imax; i++) {

       Node *use = _ioproj_catchall->fast_out(i);

       _igvn.hash_delete(use);

       imax -= replace_input(use, _ioproj_catchall, _ioproj_fallthrough);

       _igvn._worklist.push(use);

       // back up iterator

       --i;

     }

   }

   // if we generated only a slow call, we are done

   if (always_slow)

     return;

   if (_fallthroughcatchproj != NULL) {

     ctrl = _fallthroughcatchproj->clone();

     transform_later(ctrl);

     _igvn.replace_node(_fallthroughcatchproj, result_region);

   } else {

     ctrl = top();

   }

   Node *slow_result;

   if (_resproj == NULL) {

     // no uses of the allocation result

     slow_result = top();

   } else {

     slow_result = _resproj->clone();

     transform_later(slow_result);

     _igvn.replace_node(_resproj, result_phi_rawoop);

   }

   // Plug slow-path into result merge point

   result_region    ->init_req( slow_result_path, ctrl );

   result_phi_rawoop->init_req( slow_result_path, slow_result);

   result_phi_rawmem->init_req( slow_result_path, _memproj_fallthrough );

   transform_later(result_region);

   transform_later(result_phi_rawoop);

   transform_later(result_phi_rawmem);

   transform_later(result_phi_i_o);

   // This completes all paths into the result merge point

 }

 // Helper for PhaseMacroExpand::expand_allocate_common.

 // Initializes the newly-allocated storage.

 Node*

 PhaseMacroExpand::initialize_object(AllocateNode* alloc,

                                     Node* control, Node* rawmem, Node* object,

                                     Node* klass_node, Node* length,

                                     Node* size_in_bytes) {

   InitializeNode* init = alloc->initialization();

   // Store the klass & mark bits

   Node* mark_node = NULL;

   // For now only enable fast locking for non-array types

   if (UseBiasedLocking && (length == NULL)) {

     mark_node = make_load(control, rawmem, klass_node, Klass::prototype_header_offset_in_bytes() + sizeof(oopDesc), TypeRawPtr::BOTTOM, T_ADDRESS);

   } else {

     mark_node = makecon(TypeRawPtr::make((address)markOopDesc::prototype()));

   }

   rawmem = make_store(control, rawmem, object, oopDesc::mark_offset_in_bytes(), mark_node, T_ADDRESS);

   rawmem = make_store(control, rawmem, object, oopDesc::klass_offset_in_bytes(), klass_node, T_OBJECT);

   int header_size = alloc->minimum_header_size();  // conservatively small

   // Array length

   if (length != NULL) {         // Arrays need length field

     rawmem = make_store(control, rawmem, object, arrayOopDesc::length_offset_in_bytes(), length, T_INT);

     // conservatively small header size:

     header_size = arrayOopDesc::base_offset_in_bytes(T_BYTE);

     ciKlass* k = _igvn.type(klass_node)->is_klassptr()->klass();

     if (k->is_array_klass())    // we know the exact header size in most cases:

       header_size = Klass::layout_helper_header_size(k->layout_helper());

   }

   // Clear the object body, if necessary.

   if (init == NULL) {

     // The init has somehow disappeared; be cautious and clear everything.

     //

     // This can happen if a node is allocated but an uncommon trap occurs

     // immediately.  In this case, the Initialize gets associated with the

     // trap, and may be placed in a different (outer) loop, if the Allocate

     // is in a loop.  If (this is rare) the inner loop gets unrolled, then

     // there can be two Allocates to one Initialize.  The answer in all these

     // edge cases is safety first.  It is always safe to clear immediately

     // within an Allocate, and then (maybe or maybe not) clear some more later.

     if (!ZeroTLAB)

       rawmem = ClearArrayNode::clear_memory(control, rawmem, object,

                                             header_size, size_in_bytes,

                                             &_igvn);

   } else {

     if (!init->is_complete()) {

       // Try to win by zeroing only what the init does not store.

       // We can also try to do some peephole optimizations,

       // such as combining some adjacent subword stores.

       rawmem = init->complete_stores(control, rawmem, object,

                                      header_size, size_in_bytes, &_igvn);

     }

     // We have no more use for this link, since the AllocateNode goes away:

     init->set_req(InitializeNode::RawAddress, top());

     // (If we keep the link, it just confuses the register allocator,

     // who thinks he sees a real use of the address by the membar.)

   }

   return rawmem;

 }

 // Generate prefetch instructions for next allocations.

 Node* PhaseMacroExpand::prefetch_allocation(Node* i_o, Node*& needgc_false,

                                         Node*& contended_phi_rawmem,

                                         Node* old_eden_top, Node* new_eden_top,

                                         Node* length) {

    enum { fall_in_path = 1, pf_path = 2 };

    if( UseTLAB && AllocatePrefetchStyle == 2 ) {

       // Generate prefetch allocation with watermark check.

       // As an allocation hits the watermark, we will prefetch starting

       // at a "distance" away from watermark.

       Node *pf_region = new (C, 3) RegionNode(3);

       Node *pf_phi_rawmem = new (C, 3) PhiNode( pf_region, Type::MEMORY,

                                                 TypeRawPtr::BOTTOM );

       // I/O is used for Prefetch

       Node *pf_phi_abio = new (C, 3) PhiNode( pf_region, Type::ABIO );

       Node *thread = new (C, 1) ThreadLocalNode();

       transform_later(thread);

       Node *eden_pf_adr = new (C, 4) AddPNode( top()/*not oop*/, thread,

                    _igvn.MakeConX(in_bytes(JavaThread::tlab_pf_top_offset())) );

       transform_later(eden_pf_adr);

       Node *old_pf_wm = new (C, 3) LoadPNode( needgc_false,

                                    contended_phi_rawmem, eden_pf_adr,

                                    TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM );

       transform_later(old_pf_wm);

       // check against new_eden_top

       Node *need_pf_cmp = new (C, 3) CmpPNode( new_eden_top, old_pf_wm );

       transform_later(need_pf_cmp);

       Node *need_pf_bol = new (C, 2) BoolNode( need_pf_cmp, BoolTest::ge );

       transform_later(need_pf_bol);

       IfNode *need_pf_iff = new (C, 2) IfNode( needgc_false, need_pf_bol,

                                        PROB_UNLIKELY_MAG(4), COUNT_UNKNOWN );

       transform_later(need_pf_iff);

       // true node, add prefetchdistance

       Node *need_pf_true = new (C, 1) IfTrueNode( need_pf_iff );

       transform_later(need_pf_true);

       Node *need_pf_false = new (C, 1) IfFalseNode( need_pf_iff );

       transform_later(need_pf_false);

       Node *new_pf_wmt = new (C, 4) AddPNode( top(), old_pf_wm,

                                     _igvn.MakeConX(AllocatePrefetchDistance) );

       transform_later(new_pf_wmt );

       new_pf_wmt->set_req(0, need_pf_true);

       Node *store_new_wmt = new (C, 4) StorePNode( need_pf_true,

                                        contended_phi_rawmem, eden_pf_adr,

                                        TypeRawPtr::BOTTOM, new_pf_wmt );

       transform_later(store_new_wmt);

       // adding prefetches

       pf_phi_abio->init_req( fall_in_path, i_o );

       Node *prefetch_adr;

       Node *prefetch;

       uint lines = AllocatePrefetchDistance / AllocatePrefetchStepSize;

       uint step_size = AllocatePrefetchStepSize;

       uint distance = 0;

       for ( uint i = 0; i < lines; i++ ) {

         prefetch_adr = new (C, 4) AddPNode( old_pf_wm, new_pf_wmt,

                                             _igvn.MakeConX(distance) );

         transform_later(prefetch_adr);

         prefetch = new (C, 3) PrefetchWriteNode( i_o, prefetch_adr );

         transform_later(prefetch);

         distance += step_size;

         i_o = prefetch;

       }

       pf_phi_abio->set_req( pf_path, i_o );

       pf_region->init_req( fall_in_path, need_pf_false );

       pf_region->init_req( pf_path, need_pf_true );

       pf_phi_rawmem->init_req( fall_in_path, contended_phi_rawmem );

       pf_phi_rawmem->init_req( pf_path, store_new_wmt );

       transform_later(pf_region);

       transform_later(pf_phi_rawmem);

       transform_later(pf_phi_abio);

       needgc_false = pf_region;

       contended_phi_rawmem = pf_phi_rawmem;

       i_o = pf_phi_abio;

    } else if( UseTLAB && AllocatePrefetchStyle == 3 ) {

       // Insert a prefetch for each allocation only on the fast-path

       Node *pf_region = new (C, 3) RegionNode(3);

       Node *pf_phi_rawmem = new (C, 3) PhiNode( pf_region, Type::MEMORY,

                                                 TypeRawPtr::BOTTOM );

       // Generate several prefetch instructions only for arrays.

       uint lines = (length != NULL) ? AllocatePrefetchLines : 1;

       uint step_size = AllocatePrefetchStepSize;

       uint distance = AllocatePrefetchDistance;

       // Next cache address.

       Node *cache_adr = new (C, 4) AddPNode(old_eden_top, old_eden_top,

                                             _igvn.MakeConX(distance));

       transform_later(cache_adr);

       cache_adr = new (C, 2) CastP2XNode(needgc_false, cache_adr);

       transform_later(cache_adr);

       Node* mask = _igvn.MakeConX(~(intptr_t)(step_size-1));

       cache_adr = new (C, 3) AndXNode(cache_adr, mask);

       transform_later(cache_adr);

       cache_adr = new (C, 2) CastX2PNode(cache_adr);

       transform_later(cache_adr);

       // Prefetch

       Node *prefetch = new (C, 3) PrefetchWriteNode( contended_phi_rawmem, cache_adr );

       prefetch->set_req(0, needgc_false);

       transform_later(prefetch);

       contended_phi_rawmem = prefetch;

       Node *prefetch_adr;

       distance = step_size;

       for ( uint i = 1; i < lines; i++ ) {

         prefetch_adr = new (C, 4) AddPNode( cache_adr, cache_adr,

                                             _igvn.MakeConX(distance) );

         transform_later(prefetch_adr);

         prefetch = new (C, 3) PrefetchWriteNode( contended_phi_rawmem, prefetch_adr );

         transform_later(prefetch);

         distance += step_size;

         contended_phi_rawmem = prefetch;

       }

    } else if( AllocatePrefetchStyle > 0 ) {

       // Insert a prefetch for each allocation only on the fast-path

       Node *prefetch_adr;

       Node *prefetch;

       // Generate several prefetch instructions only for arrays.

       uint lines = (length != NULL) ? AllocatePrefetchLines : 1;

       uint step_size = AllocatePrefetchStepSize;

       uint distance = AllocatePrefetchDistance;

       for ( uint i = 0; i < lines; i++ ) {

         prefetch_adr = new (C, 4) AddPNode( old_eden_top, new_eden_top,

                                             _igvn.MakeConX(distance) );

         transform_later(prefetch_adr);

         prefetch = new (C, 3) PrefetchWriteNode( i_o, prefetch_adr );

         // Do not let it float too high, since if eden_top == eden_end,

         // both might be null.

         if( i == 0 ) { // Set control for first prefetch, next follows it

           prefetch->init_req(0, needgc_false);

         }

         transform_later(prefetch);

         distance += step_size;

         i_o = prefetch;

       }

    }

    return i_o;

 }

 void PhaseMacroExpand::expand_allocate(AllocateNode *alloc) {

   expand_allocate_common(alloc, NULL,

                          OptoRuntime::new_instance_Type(),

                          OptoRuntime::new_instance_Java());

 }

 void PhaseMacroExpand::expand_allocate_array(AllocateArrayNode *alloc) {

   Node* length = alloc->in(AllocateNode::ALength);

   expand_allocate_common(alloc, length,

                          OptoRuntime::new_array_Type(),

                          OptoRuntime::new_array_Java());

 }

 // we have determined that this lock/unlock can be eliminated, we simply

 // eliminate the node without expanding it.

 //

 // Note:  The membar's associated with the lock/unlock are currently not

 //        eliminated.  This should be investigated as a future enhancement.

 //

 bool PhaseMacroExpand::eliminate_locking_node(AbstractLockNode *alock) {

   if (!alock->is_eliminated()) {

     return false;

   }

   if (alock->is_Lock() && !alock->is_coarsened()) {

       // Create new "eliminated" BoxLock node and use it

       // in monitor debug info for the same object.

       BoxLockNode* oldbox = alock->box_node()->as_BoxLock();

       Node* obj = alock->obj_node();

       if (!oldbox->is_eliminated()) {

         BoxLockNode* newbox = oldbox->clone()->as_BoxLock();

         newbox->set_eliminated();

         transform_later(newbox);

         // Replace old box node with new box for all users

         // of the same object.

         for (uint i = 0; i < oldbox->outcnt();) {

           bool next_edge = true;

           Node* u = oldbox->raw_out(i);

           if (u == alock) {

             i++;

             continue; // It will be removed below

           }

           if (u->is_Lock() &&

               u->as_Lock()->obj_node() == obj &&

               // oldbox could be referenced in debug info also

               u->as_Lock()->box_node() == oldbox) {

             assert(u->as_Lock()->is_eliminated(), "sanity");

             _igvn.hash_delete(u);

             u->set_req(TypeFunc::Parms + 1, newbox);

             next_edge = false;

 #ifdef ASSERT

           } else if (u->is_Unlock() && u->as_Unlock()->obj_node() == obj) {

             assert(u->as_Unlock()->is_eliminated(), "sanity");

 #endif

           }

           // Replace old box in monitor debug info.

           if (u->is_SafePoint() && u->as_SafePoint()->jvms()) {

             SafePointNode* sfn = u->as_SafePoint();

             JVMState* youngest_jvms = sfn->jvms();

             int max_depth = youngest_jvms->depth();

             for (int depth = 1; depth <= max_depth; depth++) {

               JVMState* jvms = youngest_jvms->of_depth(depth);

               int num_mon  = jvms->nof_monitors();

               // Loop over monitors

               for (int idx = 0; idx < num_mon; idx++) {

                 Node* obj_node = sfn->monitor_obj(jvms, idx);

                 Node* box_node = sfn->monitor_box(jvms, idx);

                 if (box_node == oldbox && obj_node == obj) {

                   int j = jvms->monitor_box_offset(idx);

                   _igvn.hash_delete(u);

                   u->set_req(j, newbox);

                   next_edge = false;

                 }

               } // for (int idx = 0;

             } // for (int depth = 1;

           } // if (u->is_SafePoint()

           if (next_edge) i++;

         } // for (uint i = 0; i < oldbox->outcnt();)

       } // if (!oldbox->is_eliminated())

   } // if (alock->is_Lock() && !lock->is_coarsened())

   CompileLog* log = C->log();

   if (log != NULL) {

     log->head("eliminate_lock lock='%d'",

               alock->is_Lock());

     JVMState* p = alock->jvms();

     while (p != NULL) {

       log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));

       p = p->caller();

     }

     log->tail("eliminate_lock");

   }

   #ifndef PRODUCT

   if (PrintEliminateLocks) {

     if (alock->is_Lock()) {

       tty->print_cr("++++ Eliminating: %d Lock", alock->_idx);

     } else {

       tty->print_cr("++++ Eliminating: %d Unlock", alock->_idx);

     }

   }

   #endif

   Node* mem  = alock->in(TypeFunc::Memory);

   Node* ctrl = alock->in(TypeFunc::Control);

   extract_call_projections(alock);

   // There are 2 projections from the lock.  The lock node will

   // be deleted when its last use is subsumed below.

   assert(alock->outcnt() == 2 &&

          _fallthroughproj != NULL &&

          _memproj_fallthrough != NULL,

          "Unexpected projections from Lock/Unlock");

   Node* fallthroughproj = _fallthroughproj;

   Node* memproj_fallthrough = _memproj_fallthrough;

   // The memory projection from a lock/unlock is RawMem

   // The input to a Lock is merged memory, so extract its RawMem input

   // (unless the MergeMem has been optimized away.)

   if (alock->is_Lock()) {

     // Seach for MemBarAcquire node and delete it also.

     MemBarNode* membar = fallthroughproj->unique_ctrl_out()->as_MemBar();

     assert(membar != NULL && membar->Opcode() == Op_MemBarAcquire, "");

     Node* ctrlproj = membar->proj_out(TypeFunc::Control);

     Node* memproj = membar->proj_out(TypeFunc::Memory);

     _igvn.replace_node(ctrlproj, fallthroughproj);

     _igvn.replace_node(memproj, memproj_fallthrough);

     // Delete FastLock node also if this Lock node is unique user

     // (a loop peeling may clone a Lock node).

     Node* flock = alock->as_Lock()->fastlock_node();

     if (flock->outcnt() == 1) {

       assert(flock->unique_out() == alock, "sanity");

       _igvn.replace_node(flock, top());

     }

   }

   // Seach for MemBarRelease node and delete it also.

   if (alock->is_Unlock() && ctrl != NULL && ctrl->is_Proj() &&

       ctrl->in(0)->is_MemBar()) {

     MemBarNode* membar = ctrl->in(0)->as_MemBar();

     assert(membar->Opcode() == Op_MemBarRelease &&

            mem->is_Proj() && membar == mem->in(0), "");

     _igvn.replace_node(fallthroughproj, ctrl);

     _igvn.replace_node(memproj_fallthrough, mem);

     fallthroughproj = ctrl;

     memproj_fallthrough = mem;

     ctrl = membar->in(TypeFunc::Control);

     mem  = membar->in(TypeFunc::Memory);

   }

   _igvn.replace_node(fallthroughproj, ctrl);

   _igvn.replace_node(memproj_fallthrough, mem);

   return true;

 }

 //------------------------------expand_lock_node----------------------

 void PhaseMacroExpand::expand_lock_node(LockNode *lock) {

   Node* ctrl = lock->in(TypeFunc::Control);

   Node* mem = lock->in(TypeFunc::Memory);

   Node* obj = lock->obj_node();

   Node* box = lock->box_node();

   Node* flock = lock->fastlock_node();

   // Make the merge point

   Node *region;

   Node *mem_phi;

   Node *slow_path;

   if (UseOptoBiasInlining) {

     /*

      *  See the full description in MacroAssembler::biased_locking_enter().

      *

      *  if( (mark_word & biased_lock_mask) == biased_lock_pattern ) {

      *    // The object is biased.

      *    proto_node = klass->prototype_header;

      *    o_node = thread | proto_node;

      *    x_node = o_node ^ mark_word;

      *    if( (x_node & ~age_mask) == 0 ) { // Biased to the current thread ?

      *      // Done.

      *    } else {

      *      if( (x_node & biased_lock_mask) != 0 ) {

      *        // The klass's prototype header is no longer biased.

      *        cas(&mark_word, mark_word, proto_node)

      *        goto cas_lock;

      *      } else {

      *        // The klass's prototype header is still biased.

      *        if( (x_node & epoch_mask) != 0 ) { // Expired epoch?

      *          old = mark_word;

      *          new = o_node;

      *        } else {

      *          // Different thread or anonymous biased.

      *          old = mark_word & (epoch_mask | age_mask | biased_lock_mask);

      *          new = thread | old;

      *        }

      *        // Try to rebias.

      *        if( cas(&mark_word, old, new) == 0 ) {

      *          // Done.

      *        } else {

      *          goto slow_path; // Failed.

      *        }

      *      }

      *    }

      *  } else {

      *    // The object is not biased.

      *    cas_lock:

      *    if( FastLock(obj) == 0 ) {

      *      // Done.

      *    } else {

      *      slow_path:

      *      OptoRuntime::complete_monitor_locking_Java(obj);

      *    }

      *  }

      */

     region  = new (C, 5) RegionNode(5);

     // create a Phi for the memory state

     mem_phi = new (C, 5) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);

     Node* fast_lock_region  = new (C, 3) RegionNode(3);

     Node* fast_lock_mem_phi = new (C, 3) PhiNode( fast_lock_region, Type::MEMORY, TypeRawPtr::BOTTOM);

     // First, check mark word for the biased lock pattern.

     Node* mark_node = make_load(ctrl, mem, obj, oopDesc::mark_offset_in_bytes(), TypeX_X, TypeX_X->basic_type());

     // Get fast path - mark word has the biased lock pattern.

     ctrl = opt_bits_test(ctrl, fast_lock_region, 1, mark_node,

                          markOopDesc::biased_lock_mask_in_place,

                          markOopDesc::biased_lock_pattern, true);

     // fast_lock_region->in(1) is set to slow path.

     fast_lock_mem_phi->init_req(1, mem);

     // Now check that the lock is biased to the current thread and has

     // the same epoch and bias as Klass::_prototype_header.

     // Special-case a fresh allocation to avoid building nodes:

     Node* klass_node = AllocateNode::Ideal_klass(obj, &_igvn);

     if (klass_node == NULL) {

       Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes());

       klass_node = transform_later( LoadKlassNode::make(_igvn, mem, k_adr, _igvn.type(k_adr)->is_ptr()) );

 #ifdef _LP64

       if (UseCompressedOops && klass_node->is_DecodeN()) {

         assert(klass_node->in(1)->Opcode() == Op_LoadNKlass, "sanity");

         klass_node->in(1)->init_req(0, ctrl);

       } else

 #endif

       klass_node->init_req(0, ctrl);

     }

     Node *proto_node = make_load(ctrl, mem, klass_node, Klass::prototype_header_offset_in_bytes() + sizeof(oopDesc), TypeX_X, TypeX_X->basic_type());

     Node* thread = transform_later(new (C, 1) ThreadLocalNode());

     Node* cast_thread = transform_later(new (C, 2) CastP2XNode(ctrl, thread));

     Node* o_node = transform_later(new (C, 3) OrXNode(cast_thread, proto_node));

     Node* x_node = transform_later(new (C, 3) XorXNode(o_node, mark_node));

     // Get slow path - mark word does NOT match the value.

     Node* not_biased_ctrl =  opt_bits_test(ctrl, region, 3, x_node,

                                       (~markOopDesc::age_mask_in_place), 0);

     // region->in(3) is set to fast path - the object is biased to the current thread.

     mem_phi->init_req(3, mem);

     // Mark word does NOT match the value (thread | Klass::_prototype_header).

     // First, check biased pattern.

     // Get fast path - _prototype_header has the same biased lock pattern.

     ctrl =  opt_bits_test(not_biased_ctrl, fast_lock_region, 2, x_node,

                           markOopDesc::biased_lock_mask_in_place, 0, true);

     not_biased_ctrl = fast_lock_region->in(2); // Slow path

     // fast_lock_region->in(2) - the prototype header is no longer biased

     // and we have to revoke the bias on this object.

     // We are going to try to reset the mark of this object to the prototype

     // value and fall through to the CAS-based locking scheme.

     Node* adr = basic_plus_adr(obj, oopDesc::mark_offset_in_bytes());

     Node* cas = new (C, 5) StoreXConditionalNode(not_biased_ctrl, mem, adr,

                                                  proto_node, mark_node);

     transform_later(cas);

     Node* proj = transform_later( new (C, 1) SCMemProjNode(cas));

     fast_lock_mem_phi->init_req(2, proj);

     // Second, check epoch bits.

     Node* rebiased_region  = new (C, 3) RegionNode(3);

     Node* old_phi = new (C, 3) PhiNode( rebiased_region, TypeX_X);

     Node* new_phi = new (C, 3) PhiNode( rebiased_region, TypeX_X);

     // Get slow path - mark word does NOT match epoch bits.

     Node* epoch_ctrl =  opt_bits_test(ctrl, rebiased_region, 1, x_node,

                                       markOopDesc::epoch_mask_in_place, 0);

     // The epoch of the current bias is not valid, attempt to rebias the object

     // toward the current thread.

     rebiased_region->init_req(2, epoch_ctrl);

     old_phi->init_req(2, mark_node);

     new_phi->init_req(2, o_node);

     // rebiased_region->in(1) is set to fast path.

     // The epoch of the current bias is still valid but we know

     // nothing about the owner; it might be set or it might be clear.

     Node* cmask   = MakeConX(markOopDesc::biased_lock_mask_in_place |

                              markOopDesc::age_mask_in_place |

                              markOopDesc::epoch_mask_in_place);

     Node* old = transform_later(new (C, 3) AndXNode(mark_node, cmask));

     cast_thread = transform_later(new (C, 2) CastP2XNode(ctrl, thread));

     Node* new_mark = transform_later(new (C, 3) OrXNode(cast_thread, old));

     old_phi->init_req(1, old);

     new_phi->init_req(1, new_mark);

     transform_later(rebiased_region);

     transform_later(old_phi);

     transform_later(new_phi);

     // Try to acquire the bias of the object using an atomic operation.

     // If this fails we will go in to the runtime to revoke the object's bias.

     cas = new (C, 5) StoreXConditionalNode(rebiased_region, mem, adr,

                                            new_phi, old_phi);

     transform_later(cas);

     proj = transform_later( new (C, 1) SCMemProjNode(cas));

     // Get slow path - Failed to CAS.

     not_biased_ctrl = opt_bits_test(rebiased_region, region, 4, cas, 0, 0);

     mem_phi->init_req(4, proj);

     // region->in(4) is set to fast path - the object is rebiased to the current thread.

     // Failed to CAS.

     slow_path  = new (C, 3) RegionNode(3);

     Node *slow_mem = new (C, 3) PhiNode( slow_path, Type::MEMORY, TypeRawPtr::BOTTOM);

     slow_path->init_req(1, not_biased_ctrl); // Capture slow-control

     slow_mem->init_req(1, proj);

     // Call CAS-based locking scheme (FastLock node).

     transform_later(fast_lock_region);

     transform_later(fast_lock_mem_phi);

     // Get slow path - FastLock failed to lock the object.

     ctrl = opt_bits_test(fast_lock_region, region, 2, flock, 0, 0);

     mem_phi->init_req(2, fast_lock_mem_phi);

     // region->in(2) is set to fast path - the object is locked to the current thread.

     slow_path->init_req(2, ctrl); // Capture slow-control

     slow_mem->init_req(2, fast_lock_mem_phi);

     transform_later(slow_path);

     transform_later(slow_mem);

     // Reset lock's memory edge.

     lock->set_req(TypeFunc::Memory, slow_mem);

   } else {

     region  = new (C, 3) RegionNode(3);

     // create a Phi for the memory state

     mem_phi = new (C, 3) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);

     // Optimize test; set region slot 2

     slow_path = opt_bits_test(ctrl, region, 2, flock, 0, 0);

     mem_phi->init_req(2, mem);

   }

   // Make slow path call

   CallNode *call = make_slow_call( (CallNode *) lock, OptoRuntime::complete_monitor_enter_Type(), OptoRuntime::complete_monitor_locking_Java(), NULL, slow_path, obj, box );

   extract_call_projections(call);

   // Slow path can only throw asynchronous exceptions, which are always

   // de-opted.  So the compiler thinks the slow-call can never throw an

   // exception.  If it DOES throw an exception we would need the debug

   // info removed first (since if it throws there is no monitor).

   assert ( _ioproj_fallthrough == NULL && _ioproj_catchall == NULL &&

            _memproj_catchall == NULL && _catchallcatchproj == NULL, "Unexpected projection from Lock");

   // Capture slow path

   // disconnect fall-through projection from call and create a new one

   // hook up users of fall-through projection to region

   Node *slow_ctrl = _fallthroughproj->clone();

   transform_later(slow_ctrl);

   _igvn.hash_delete(_fallthroughproj);

   _fallthroughproj->disconnect_inputs(NULL);

   region->init_req(1, slow_ctrl);

   // region inputs are now complete

   transform_later(region);

   _igvn.replace_node(_fallthroughproj, region);

   Node *memproj = transform_later( new(C, 1) ProjNode(call, TypeFunc::Memory) );

   mem_phi->init_req(1, memproj );

   transform_later(mem_phi);

   _igvn.replace_node(_memproj_fallthrough, mem_phi);

 }

 //------------------------------expand_unlock_node----------------------

 void PhaseMacroExpand::expand_unlock_node(UnlockNode *unlock) {

   Node* ctrl = unlock->in(TypeFunc::Control);

   Node* mem = unlock->in(TypeFunc::Memory);

   Node* obj = unlock->obj_node();

   Node* box = unlock->box_node();

   // No need for a null check on unlock

   // Make the merge point

   Node *region;

   Node *mem_phi;

   if (UseOptoBiasInlining) {

     // Check for biased locking unlock case, which is a no-op.

     // See the full description in MacroAssembler::biased_locking_exit().

     region  = new (C, 4) RegionNode(4);

     // create a Phi for the memory state

     mem_phi = new (C, 4) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);

     mem_phi->init_req(3, mem);

     Node* mark_node = make_load(ctrl, mem, obj, oopDesc::mark_offset_in_bytes(), TypeX_X, TypeX_X->basic_type());

     ctrl = opt_bits_test(ctrl, region, 3, mark_node,

                          markOopDesc::biased_lock_mask_in_place,

                          markOopDesc::biased_lock_pattern);

   } else {

     region  = new (C, 3) RegionNode(3);

     // create a Phi for the memory state

     mem_phi = new (C, 3) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);

   }

   FastUnlockNode *funlock = new (C, 3) FastUnlockNode( ctrl, obj, box );

   funlock = transform_later( funlock )->as_FastUnlock();

   // Optimize test; set region slot 2

   Node *slow_path = opt_bits_test(ctrl, region, 2, funlock, 0, 0);

   CallNode *call = make_slow_call( (CallNode *) unlock, OptoRuntime::complete_monitor_exit_Type(), CAST_FROM_FN_PTR(address, SharedRuntime::complete_monitor_unlocking_C), "complete_monitor_unlocking_C", slow_path, obj, box );

   extract_call_projections(call);

   assert ( _ioproj_fallthrough == NULL && _ioproj_catchall == NULL &&

            _memproj_catchall == NULL && _catchallcatchproj == NULL, "Unexpected projection from Lock");

   // No exceptions for unlocking

   // Capture slow path

   // disconnect fall-through projection from call and create a new one

   // hook up users of fall-through projection to region

   Node *slow_ctrl = _fallthroughproj->clone();

   transform_later(slow_ctrl);

   _igvn.hash_delete(_fallthroughproj);

   _fallthroughproj->disconnect_inputs(NULL);

   region->init_req(1, slow_ctrl);

   // region inputs are now complete

   transform_later(region);

   _igvn.replace_node(_fallthroughproj, region);

   Node *memproj = transform_later( new(C, 1) ProjNode(call, TypeFunc::Memory) );

   mem_phi->init_req(1, memproj );

   mem_phi->init_req(2, mem);

   transform_later(mem_phi);

   _igvn.replace_node(_memproj_fallthrough, mem_phi);

 }

 //------------------------------expand_macro_nodes----------------------

 //  Returns true if a failure occurred.

 bool PhaseMacroExpand::expand_macro_nodes() {

   if (C->macro_count() == 0)

     return false;

   // First, attempt to eliminate locks

   bool progress = true;

   while (progress) {

     progress = false;

     for (int i = C->macro_count(); i > 0; i--) {

       Node * n = C->macro_node(i-1);

       bool success = false;

       debug_only(int old_macro_count = C->macro_count(););

       if (n->is_AbstractLock()) {

         success = eliminate_locking_node(n->as_AbstractLock());

       } else if (n->Opcode() == Op_Opaque1 || n->Opcode() == Op_Opaque2) {

         _igvn.replace_node(n, n->in(1));

         success = true;

       }

       assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");

       progress = progress || success;

     }

   }

   // Next, attempt to eliminate allocations

   progress = true;

   while (progress) {

     progress = false;

     for (int i = C->macro_count(); i > 0; i--) {

       Node * n = C->macro_node(i-1);

       bool success = false;

       debug_only(int old_macro_count = C->macro_count(););

       switch (n->class_id()) {

       case Node::Class_Allocate:

       case Node::Class_AllocateArray:

         success = eliminate_allocate_node(n->as_Allocate());

         break;

       case Node::Class_Lock:

       case Node::Class_Unlock:

         assert(!n->as_AbstractLock()->is_eliminated(), "sanity");

         break;

       default:

         assert(false, "unknown node type in macro list");

       }

       assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");

       progress = progress || success;

     }

   }

   // Make sure expansion will not cause node limit to be exceeded.

   // Worst case is a macro node gets expanded into about 50 nodes.

   // Allow 50% more for optimization.

   if (C->check_node_count(C->macro_count() * 75, "out of nodes before macro expansion" ) )

     return true;

   // expand "macro" nodes

   // nodes are removed from the macro list as they are processed

   while (C->macro_count() > 0) {

     int macro_count = C->macro_count();

     Node * n = C->macro_node(macro_count-1);

     assert(n->is_macro(), "only macro nodes expected here");

     if (_igvn.type(n) == Type::TOP || n->in(0)->is_top() ) {

       // node is unreachable, so don't try to expand it

       C->remove_macro_node(n);

       continue;

     }

     switch (n->class_id()) {

     case Node::Class_Allocate:

       expand_allocate(n->as_Allocate());

       break;

     case Node::Class_AllocateArray:

       expand_allocate_array(n->as_AllocateArray());

       break;

     case Node::Class_Lock:

       expand_lock_node(n->as_Lock());

       break;

     case Node::Class_Unlock:

       expand_unlock_node(n->as_Unlock());

       break;

     default:

       assert(false, "unknown node type in macro list");

     }

     assert(C->macro_count() < macro_count, "must have deleted a node from macro list");

     if (C->failing())  return true;

   }

   _igvn.set_delay_transform(false);

   _igvn.optimize();

   return false;

 }