jdk8-mips64-public/hotspot: src/share/vm/opto/macro.cpp@bd12fff78df5 (annotated)

src/share/vm/opto/macro.cpp@bd12fff78df5 (annotated)

src/share/vm/opto/macro.cpp

Wed, 25 Nov 2009 12:09:02 -0800

author: cfang
date: Wed, 25 Nov 2009 12:09:02 -0800
changeset 1516: bd12fff78df5
parent 1515: 7c57aead6d3e
child 1535: f96a1a986f7b
permissions: -rw-r--r--

6904191: OptimizeStringConcat should be product instead of experimental
Summary: Make OptimizeStringConcat a product VM option(contributed by never)
Reviewed-by: never

 /*
  * Copyright 2005-2009 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  * CA 95054 USA or visit www.sun.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.hash_delete(oldcall);
   _igvn.subsume_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->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.hash_delete(n);
           _igvn.subsume_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()) {
           // 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()) {
             _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.hash_delete(alloc);
   _igvn.subsume_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(NULL, 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) {
    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.
       enum { fall_in_path = 1, pf_path = 2 };
       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( 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;
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/opto/macro.cpp@bd12fff78df5 (annotated)

src/share/vm/opto/macro.cpp