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src/hotspot/share/gc/z/c2/zBarrierSetC2.cpp

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@@ -20,26 +20,19 @@
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  */
 
 #include "precompiled.hpp"
-#include "opto/castnode.hpp"
 #include "opto/compile.hpp"
+#include "opto/castnode.hpp"
 #include "opto/escape.hpp"
 #include "opto/graphKit.hpp"
+#include "opto/idealKit.hpp"
 #include "opto/loopnode.hpp"
-#include "opto/machnode.hpp"
 #include "opto/macro.hpp"
-#include "opto/memnode.hpp"
-#include "opto/movenode.hpp"
 #include "opto/node.hpp"
-#include "opto/phase.hpp"
-#include "opto/phaseX.hpp"
-#include "opto/rootnode.hpp"
 #include "opto/type.hpp"
-#include "utilities/copy.hpp"
-#include "utilities/growableArray.hpp"
 #include "utilities/macros.hpp"
 #include "gc/z/zBarrierSet.hpp"
 #include "gc/z/c2/zBarrierSetC2.hpp"
 #include "gc/z/zThreadLocalData.hpp"
 #include "gc/z/zBarrierSetRuntime.hpp"

@@ -89,11 +82,11 @@
 
   // 3. This step checks for the phi corresponding to an optimized load barrier expansion
   if (node->is_Phi()) {
     PhiNode* phi = node->as_Phi();
     Node* n = phi->in(1);
-    if (n != NULL && n->is_LoadBarrierSlowReg()) {
+    if (n != NULL && (n->is_LoadBarrierSlowReg() ||  n->is_LoadBarrierWeakSlowReg())) {
       return true;
     }
   }
 
   return false;

@@ -126,33 +119,68 @@
   if (node->is_LoadBarrier() && !node->as_LoadBarrier()->has_true_uses()) {
     igvn->_worklist.push(node);
   }
 }
 
-static bool load_require_barrier(LoadNode* load)      { return ((load->barrier_data() & RequireBarrier) != 0); }
-static bool load_has_weak_barrier(LoadNode* load)     { return ((load->barrier_data() & WeakBarrier) != 0); }
-static bool load_has_expanded_barrier(LoadNode* load) { return ((load->barrier_data() & ExpandedBarrier) != 0); }
-static void load_set_expanded_barrier(LoadNode* load) { return load->set_barrier_data(ExpandedBarrier); }
-
-static void load_set_barrier(LoadNode* load, bool weak)    {
-  if (weak) {
-    load->set_barrier_data(WeakBarrier);
-  } else {
-    load->set_barrier_data(RequireBarrier);
+void ZBarrierSetC2::find_dominating_barriers(PhaseIterGVN& igvn) {
+  // Look for dominating barriers on the same address only once all
+  // other loop opts are over. Loop opts may cause a safepoint to be
+  // inserted between a barrier and its dominating barrier.
+  Compile* C = Compile::current();
+  ZBarrierSetC2* bs = (ZBarrierSetC2*)BarrierSet::barrier_set()->barrier_set_c2();
+  ZBarrierSetC2State* s = bs->state();
+  if (s->load_barrier_count() >= 2) {
+    Compile::TracePhase tp("idealLoop", &C->timers[Phase::_t_idealLoop]);
+    PhaseIdealLoop::optimize(igvn, LoopOptsLastRound);
+    if (C->major_progress()) C->print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
   }
 }
 
+void ZBarrierSetC2::add_users_to_worklist(Unique_Node_List* worklist) const {
+  // Permanent temporary workaround
+  // Loadbarriers may have non-obvious dead uses keeping them alive during parsing. The use is
+  // removed by RemoveUseless (after parsing, before optimize) but the barriers won't be added to
+  // the worklist. Unless we add them explicitly they are not guaranteed to end up there.
+  ZBarrierSetC2State* s = state();
+
+  for (int i = 0; i < s->load_barrier_count(); i++) {
+    LoadBarrierNode* n = s->load_barrier_node(i);
+    worklist->push(n);
+  }
+}
+
+const TypeFunc* ZBarrierSetC2::load_barrier_Type() const {
+  const Type** fields;
+
+  // Create input types (domain)
+  fields = TypeTuple::fields(2);
+  fields[TypeFunc::Parms+0] = TypeInstPtr::NOTNULL;
+  fields[TypeFunc::Parms+1] = TypeOopPtr::BOTTOM;
+  const TypeTuple *domain = TypeTuple::make(TypeFunc::Parms+2, fields);
+
+  // Create result type (range)
+  fields = TypeTuple::fields(1);
+  fields[TypeFunc::Parms+0] = TypeInstPtr::BOTTOM;
+  const TypeTuple *range = TypeTuple::make(TypeFunc::Parms+1, fields);
+
+  return TypeFunc::make(domain, range);
+}
+
 // == LoadBarrierNode ==
 
 LoadBarrierNode::LoadBarrierNode(Compile* C,
                                  Node* c,
                                  Node* mem,
                                  Node* val,
                                  Node* adr,
-                                 bool weak) :
+                                 bool weak,
+                                 bool writeback,
+                                 bool oop_reload_allowed) :
     MultiNode(Number_of_Inputs),
-    _weak(weak) {
+    _weak(weak),
+    _writeback(writeback),
+    _oop_reload_allowed(oop_reload_allowed) {
   init_req(Control, c);
   init_req(Memory, mem);
   init_req(Oop, val);
   init_req(Address, adr);
   init_req(Similar, C->top());

@@ -187,12 +215,12 @@
 
 const Type *LoadBarrierNode::Value(PhaseGVN *phase) const {
   const Type** floadbarrier = (const Type **)(phase->C->type_arena()->Amalloc_4((Number_of_Outputs)*sizeof(Type*)));
   const Type* val_t = phase->type(in(Oop));
   floadbarrier[Control] = Type::CONTROL;
-  floadbarrier[Memory]  = Type::MEMORY;
-  floadbarrier[Oop]     = val_t;
+  floadbarrier[Memory] = Type::MEMORY;
+  floadbarrier[Oop] = val_t;
   return TypeTuple::make(Number_of_Outputs, floadbarrier);
 }
 
 bool LoadBarrierNode::is_dominator(PhaseIdealLoop* phase, bool linear_only, Node *d, Node *n) {
   if (phase != NULL) {

@@ -208,15 +236,10 @@
 
   return false;
 }
 
 LoadBarrierNode* LoadBarrierNode::has_dominating_barrier(PhaseIdealLoop* phase, bool linear_only, bool look_for_similar) {
-  if (is_weak()) {
-    // Weak barriers can't be eliminated
-    return NULL;
-  }
-
   Node* val = in(LoadBarrierNode::Oop);
   if (in(Similar)->is_Proj() && in(Similar)->in(0)->is_LoadBarrier()) {
     LoadBarrierNode* lb = in(Similar)->in(0)->as_LoadBarrier();
     assert(lb->in(Address) == in(Address), "");
     // Load barrier on Similar edge dominates so if it now has the Oop field it can replace this barrier.

@@ -241,11 +264,11 @@
         return u->as_LoadBarrier();
       }
     }
   }
 
-  if (can_be_eliminated()) {
+  if (ZVerifyLoadBarriers || can_be_eliminated()) {
     return NULL;
   }
 
   if (!look_for_similar) {
     return NULL;

@@ -291,11 +314,11 @@
             }
           }
         }
         if (ok) {
           assert(dom_found, "");
-          return u->as_LoadBarrier();
+          return u->as_LoadBarrier();;
         }
         break;
       }
     }
   }

@@ -303,11 +326,10 @@
   return NULL;
 }
 
 void LoadBarrierNode::push_dominated_barriers(PhaseIterGVN* igvn) const {
   // Change to that barrier may affect a dominated barrier so re-push those
-  assert(!is_weak(), "sanity");
   Node* val = in(LoadBarrierNode::Oop);
 
   for (DUIterator_Fast imax, i = val->fast_outs(imax); i < imax; i++) {
     Node* u = val->fast_out(i);
     if (u != this && u->is_LoadBarrier() && u->in(Oop) == val) {

@@ -331,13 +353,17 @@
     }
   }
 }
 
 Node *LoadBarrierNode::Identity(PhaseGVN *phase) {
+  if (!phase->C->directive()->ZOptimizeLoadBarriersOption) {
+    return this;
+  }
+
+  bool redundant_addr = false;
   LoadBarrierNode* dominating_barrier = has_dominating_barrier(NULL, true, false);
   if (dominating_barrier != NULL) {
-    assert(!is_weak(), "Weak barriers cant be eliminated");
     assert(dominating_barrier->in(Oop) == in(Oop), "");
     return dominating_barrier;
   }
 
   return this;

@@ -346,37 +372,37 @@
 Node *LoadBarrierNode::Ideal(PhaseGVN *phase, bool can_reshape) {
   if (remove_dead_region(phase, can_reshape)) {
     return this;
   }
 
-  Node *val = in(Oop);
-  Node *mem = in(Memory);
-  Node *ctrl = in(Control);
-
+  Node* val = in(Oop);
+  Node* mem = in(Memory);
+  Node* ctrl = in(Control);
+  Node* adr = in(Address);
   assert(val->Opcode() != Op_LoadN, "");
-  assert(val->Opcode() != Op_DecodeN, "");
 
   if (mem->is_MergeMem()) {
-    Node *new_mem = mem->as_MergeMem()->memory_at(Compile::AliasIdxRaw);
+    Node* new_mem = mem->as_MergeMem()->memory_at(Compile::AliasIdxRaw);
     set_req(Memory, new_mem);
     if (mem->outcnt() == 0 && can_reshape) {
       phase->is_IterGVN()->_worklist.push(mem);
     }
+
     return this;
   }
 
-  LoadBarrierNode *dominating_barrier = NULL;
-  if (!is_weak()) {
-    dominating_barrier = has_dominating_barrier(NULL, !can_reshape, !phase->C->major_progress());
-    if (dominating_barrier != NULL && dominating_barrier->in(Oop) != in(Oop)) {
-      assert(in(Address) == dominating_barrier->in(Address), "");
-      set_req(Similar, dominating_barrier->proj_out(Oop));
-      return this;
-    }
+  bool optimizeLoadBarriers = phase->C->directive()->ZOptimizeLoadBarriersOption;
+  LoadBarrierNode* dominating_barrier = optimizeLoadBarriers ? has_dominating_barrier(NULL, !can_reshape, !phase->C->major_progress()) : NULL;
+  if (dominating_barrier != NULL && dominating_barrier->in(Oop) != in(Oop)) {
+    assert(in(Address) == dominating_barrier->in(Address), "");
+    set_req(Similar, dominating_barrier->proj_out(Oop));
+    return this;
   }
 
-  bool eliminate = can_reshape && (dominating_barrier != NULL || !has_true_uses());
+  bool eliminate = (optimizeLoadBarriers && !(val->is_Phi() || val->Opcode() == Op_LoadP || val->Opcode() == Op_GetAndSetP || val->is_DecodeN())) ||
+                   (can_reshape && (dominating_barrier != NULL || !has_true_uses()));
+
   if (eliminate) {
     if (can_reshape) {
       PhaseIterGVN* igvn = phase->is_IterGVN();
       Node* out_ctrl = proj_out_or_null(Control);
       Node* out_res = proj_out_or_null(Oop);

@@ -387,28 +413,28 @@
 
       // That transformation may cause the Similar edge on the load barrier to be invalid
       fix_similar_in_uses(igvn);
       if (out_res != NULL) {
         if (dominating_barrier != NULL) {
-          assert(!is_weak(), "Sanity");
           igvn->replace_node(out_res, dominating_barrier->proj_out(Oop));
         } else {
           igvn->replace_node(out_res, val);
         }
       }
     }
+
     return new ConINode(TypeInt::ZERO);
   }
 
   // If the Similar edge is no longer a load barrier, clear it
   Node* similar = in(Similar);
   if (!similar->is_top() && !(similar->is_Proj() && similar->in(0)->is_LoadBarrier())) {
     set_req(Similar, phase->C->top());
     return this;
   }
 
-  if (can_reshape && !is_weak()) {
+  if (can_reshape) {
     // If this barrier is linked through the Similar edge by a
     // dominated barrier and both barriers have the same Oop field,
     // the dominated barrier can go away, so push it for reprocessing.
     // We also want to avoid a barrier to depend on another dominating
     // barrier through its Similar edge that itself depend on another

@@ -418,14 +444,14 @@
     Node* out_res = proj_out(Oop);
     for (DUIterator_Fast imax, i = out_res->fast_outs(imax); i < imax; i++) {
       Node* u = out_res->fast_out(i);
       if (u->is_LoadBarrier() && u->in(Similar) == out_res &&
           (u->in(Oop) == val || !u->in(Similar)->is_top())) {
-        assert(!u->as_LoadBarrier()->is_weak(), "Sanity");
         igvn->_worklist.push(u);
       }
     }
+
     push_dominated_barriers(igvn);
   }
 
   return NULL;
 }

@@ -451,21 +477,215 @@
   }
 }
 
 bool LoadBarrierNode::has_true_uses() const {
   Node* out_res = proj_out_or_null(Oop);
-  if (out_res != NULL) {
-    for (DUIterator_Fast imax, i = out_res->fast_outs(imax); i < imax; i++) {
-      Node *u = out_res->fast_out(i);
-      if (!u->is_LoadBarrier() || u->in(Similar) != out_res) {
-        return true;
-      }
+  if (out_res == NULL) {
+    return false;
+  }
+
+  for (DUIterator_Fast imax, i = out_res->fast_outs(imax); i < imax; i++) {
+    Node* u = out_res->fast_out(i);
+    if (!u->is_LoadBarrier() || u->in(Similar) != out_res) {
+      return true;
     }
   }
+
   return false;
 }
 
+// == Accesses ==
+
+Node* ZBarrierSetC2::make_cas_loadbarrier(C2AtomicParseAccess& access) const {
+  assert(!UseCompressedOops, "Not allowed");
+  CompareAndSwapNode* cas = (CompareAndSwapNode*)access.raw_access();
+  PhaseGVN& gvn = access.gvn();
+  Compile* C = Compile::current();
+  GraphKit* kit = access.kit();
+
+  Node* in_ctrl     = cas->in(MemNode::Control);
+  Node* in_mem      = cas->in(MemNode::Memory);
+  Node* in_adr      = cas->in(MemNode::Address);
+  Node* in_val      = cas->in(MemNode::ValueIn);
+  Node* in_expected = cas->in(LoadStoreConditionalNode::ExpectedIn);
+
+  float likely                   = PROB_LIKELY(0.999);
+
+  const TypePtr *adr_type        = gvn.type(in_adr)->isa_ptr();
+  Compile::AliasType* alias_type = C->alias_type(adr_type);
+  int alias_idx                  = C->get_alias_index(adr_type);
+
+  // Outer check - true: continue, false: load and check
+  Node* region   = new RegionNode(3);
+  Node* phi      = new PhiNode(region, TypeInt::BOOL);
+  Node* phi_mem  = new PhiNode(region, Type::MEMORY, adr_type);
+
+  // Inner check - is the healed ref equal to the expected
+  Node* region2  = new RegionNode(3);
+  Node* phi2     = new PhiNode(region2, TypeInt::BOOL);
+  Node* phi_mem2 = new PhiNode(region2, Type::MEMORY, adr_type);
+
+  // CAS node returns 0 or 1
+  Node* cmp     = gvn.transform(new CmpINode(cas, kit->intcon(0)));
+  Node* bol     = gvn.transform(new BoolNode(cmp, BoolTest::ne))->as_Bool();
+  IfNode* iff   = gvn.transform(new IfNode(in_ctrl, bol, likely, COUNT_UNKNOWN))->as_If();
+  Node* then    = gvn.transform(new IfTrueNode(iff));
+  Node* elsen   = gvn.transform(new IfFalseNode(iff));
+
+  Node* scmemproj1   = gvn.transform(new SCMemProjNode(cas));
+
+  kit->set_memory(scmemproj1, alias_idx);
+  phi_mem->init_req(1, scmemproj1);
+  phi_mem2->init_req(2, scmemproj1);
+
+  // CAS fail - reload and heal oop
+  Node* reload      = kit->make_load(elsen, in_adr, TypeOopPtr::BOTTOM, T_OBJECT, MemNode::unordered);
+  Node* barrier     = gvn.transform(new LoadBarrierNode(C, elsen, scmemproj1, reload, in_adr, false, true, false));
+  Node* barrierctrl = gvn.transform(new ProjNode(barrier, LoadBarrierNode::Control));
+  Node* barrierdata = gvn.transform(new ProjNode(barrier, LoadBarrierNode::Oop));
+
+  // Check load
+  Node* tmpX    = gvn.transform(new CastP2XNode(NULL, barrierdata));
+  Node* in_expX = gvn.transform(new CastP2XNode(NULL, in_expected));
+  Node* cmp2    = gvn.transform(new CmpXNode(tmpX, in_expX));
+  Node *bol2    = gvn.transform(new BoolNode(cmp2, BoolTest::ne))->as_Bool();
+  IfNode* iff2  = gvn.transform(new IfNode(barrierctrl, bol2, likely, COUNT_UNKNOWN))->as_If();
+  Node* then2   = gvn.transform(new IfTrueNode(iff2));
+  Node* elsen2  = gvn.transform(new IfFalseNode(iff2));
+
+  // redo CAS
+  Node* cas2       = gvn.transform(new CompareAndSwapPNode(elsen2, kit->memory(alias_idx), in_adr, in_val, in_expected, cas->order()));
+  Node* scmemproj2 = gvn.transform(new SCMemProjNode(cas2));
+  kit->set_control(elsen2);
+  kit->set_memory(scmemproj2, alias_idx);
+
+  // Merge inner flow - check if healed oop was equal too expected.
+  region2->set_req(1, kit->control());
+  region2->set_req(2, then2);
+  phi2->set_req(1, cas2);
+  phi2->set_req(2, kit->intcon(0));
+  phi_mem2->init_req(1, scmemproj2);
+  kit->set_memory(phi_mem2, alias_idx);
+
+  // Merge outer flow - then check if first CAS succeeded
+  region->set_req(1, then);
+  region->set_req(2, region2);
+  phi->set_req(1, kit->intcon(1));
+  phi->set_req(2, phi2);
+  phi_mem->init_req(2, phi_mem2);
+  kit->set_memory(phi_mem, alias_idx);
+
+  gvn.transform(region2);
+  gvn.transform(phi2);
+  gvn.transform(phi_mem2);
+  gvn.transform(region);
+  gvn.transform(phi);
+  gvn.transform(phi_mem);
+
+  kit->set_control(region);
+  kit->insert_mem_bar(Op_MemBarCPUOrder);
+
+  return phi;
+}
+
+Node* ZBarrierSetC2::make_cmpx_loadbarrier(C2AtomicParseAccess& access) const {
+  CompareAndExchangePNode* cmpx = (CompareAndExchangePNode*)access.raw_access();
+  GraphKit* kit = access.kit();
+  PhaseGVN& gvn = kit->gvn();
+  Compile* C = Compile::current();
+
+  Node* in_ctrl     = cmpx->in(MemNode::Control);
+  Node* in_mem      = cmpx->in(MemNode::Memory);
+  Node* in_adr      = cmpx->in(MemNode::Address);
+  Node* in_val      = cmpx->in(MemNode::ValueIn);
+  Node* in_expected = cmpx->in(LoadStoreConditionalNode::ExpectedIn);
+
+  float likely                   = PROB_LIKELY(0.999);
+
+  const TypePtr *adr_type        = cmpx->get_ptr_type();
+  Compile::AliasType* alias_type = C->alias_type(adr_type);
+  int alias_idx                  = C->get_alias_index(adr_type);
+
+  // Outer check - true: continue, false: load and check
+  Node* region  = new RegionNode(3);
+  Node* phi     = new PhiNode(region, adr_type);
+
+  // Inner check - is the healed ref equal to the expected
+  Node* region2 = new RegionNode(3);
+  Node* phi2    = new PhiNode(region2, adr_type);
+
+  // Check if cmpx succeeded
+  Node* cmp     = gvn.transform(new CmpPNode(cmpx, in_expected));
+  Node* bol     = gvn.transform(new BoolNode(cmp, BoolTest::eq))->as_Bool();
+  IfNode* iff   = gvn.transform(new IfNode(in_ctrl, bol, likely, COUNT_UNKNOWN))->as_If();
+  Node* then    = gvn.transform(new IfTrueNode(iff));
+  Node* elsen   = gvn.transform(new IfFalseNode(iff));
+
+  Node* scmemproj1  = gvn.transform(new SCMemProjNode(cmpx));
+  kit->set_memory(scmemproj1, alias_idx);
+
+  // CAS fail - reload and heal oop
+  Node* reload      = kit->make_load(elsen, in_adr, TypeOopPtr::BOTTOM, T_OBJECT, MemNode::unordered);
+  Node* barrier     = gvn.transform(new LoadBarrierNode(C, elsen, scmemproj1, reload, in_adr, false, true, false));
+  Node* barrierctrl = gvn.transform(new ProjNode(barrier, LoadBarrierNode::Control));
+  Node* barrierdata = gvn.transform(new ProjNode(barrier, LoadBarrierNode::Oop));
+
+  // Check load
+  Node* tmpX    = gvn.transform(new CastP2XNode(NULL, barrierdata));
+  Node* in_expX = gvn.transform(new CastP2XNode(NULL, in_expected));
+  Node* cmp2    = gvn.transform(new CmpXNode(tmpX, in_expX));
+  Node *bol2    = gvn.transform(new BoolNode(cmp2, BoolTest::ne))->as_Bool();
+  IfNode* iff2  = gvn.transform(new IfNode(barrierctrl, bol2, likely, COUNT_UNKNOWN))->as_If();
+  Node* then2   = gvn.transform(new IfTrueNode(iff2));
+  Node* elsen2  = gvn.transform(new IfFalseNode(iff2));
+
+  // Redo CAS
+  Node* cmpx2      = gvn.transform(new CompareAndExchangePNode(elsen2, kit->memory(alias_idx), in_adr, in_val, in_expected, adr_type, cmpx->get_ptr_type(), cmpx->order()));
+  Node* scmemproj2 = gvn.transform(new SCMemProjNode(cmpx2));
+  kit->set_control(elsen2);
+  kit->set_memory(scmemproj2, alias_idx);
+
+  // Merge inner flow - check if healed oop was equal too expected.
+  region2->set_req(1, kit->control());
+  region2->set_req(2, then2);
+  phi2->set_req(1, cmpx2);
+  phi2->set_req(2, barrierdata);
+
+  // Merge outer flow - then check if first cas succeeded
+  region->set_req(1, then);
+  region->set_req(2, region2);
+  phi->set_req(1, cmpx);
+  phi->set_req(2, phi2);
+
+  gvn.transform(region2);
+  gvn.transform(phi2);
+  gvn.transform(region);
+  gvn.transform(phi);
+
+  kit->set_control(region);
+  kit->set_memory(in_mem, alias_idx);
+  kit->insert_mem_bar(Op_MemBarCPUOrder);
+
+  return phi;
+}
+
+Node* ZBarrierSetC2::load_barrier(GraphKit* kit, Node* val, Node* adr, bool weak, bool writeback, bool oop_reload_allowed) const {
+  PhaseGVN& gvn = kit->gvn();
+  Node* barrier = new LoadBarrierNode(Compile::current(), kit->control(), kit->memory(TypeRawPtr::BOTTOM), val, adr, weak, writeback, oop_reload_allowed);
+  Node* transformed_barrier = gvn.transform(barrier);
+
+  if (transformed_barrier->is_LoadBarrier()) {
+    if (barrier == transformed_barrier) {
+      kit->set_control(gvn.transform(new ProjNode(barrier, LoadBarrierNode::Control)));
+    }
+    Node* result = gvn.transform(new ProjNode(transformed_barrier, LoadBarrierNode::Oop));
+    return result;
+  } else {
+    return val;
+  }
+}
+
 static bool barrier_needed(C2Access& access) {
   return ZBarrierSet::barrier_needed(access.decorators(), access.type());
 }
 
 Node* ZBarrierSetC2::load_at_resolved(C2Access& access, const Type* val_type) const {

@@ -473,62 +693,270 @@
   if (!barrier_needed(access)) {
     return p;
   }
 
   bool weak = (access.decorators() & ON_WEAK_OOP_REF) != 0;
-  if (p->isa_Load()) {
-    load_set_barrier(p->as_Load(), weak);
+
+  assert(access.is_parse_access(), "entry not supported at optimization time");
+  C2ParseAccess& parse_access = static_cast<C2ParseAccess&>(access);
+  GraphKit* kit = parse_access.kit();
+  PhaseGVN& gvn = kit->gvn();
+  Node* adr = access.addr().node();
+  Node* heap_base_oop = access.base();
+  bool unsafe = (access.decorators() & C2_UNSAFE_ACCESS) != 0;
+  if (unsafe) {
+    if (!ZVerifyLoadBarriers) {
+      p = load_barrier(kit, p, adr);
+    } else {
+      if (!TypePtr::NULL_PTR->higher_equal(gvn.type(heap_base_oop))) {
+        p = load_barrier(kit, p, adr);
+      } else {
+        IdealKit ideal(kit);
+        IdealVariable res(ideal);
+#define __ ideal.
+        __ declarations_done();
+        __ set(res, p);
+        __ if_then(heap_base_oop, BoolTest::ne, kit->null(), PROB_UNLIKELY(0.999)); {
+          kit->sync_kit(ideal);
+          p = load_barrier(kit, p, adr);
+          __ set(res, p);
+          __ sync_kit(kit);
+        } __ end_if();
+        kit->final_sync(ideal);
+        p = __ value(res);
+#undef __
+      }
+    }
+    return p;
+  } else {
+    return load_barrier(parse_access.kit(), p, access.addr().node(), weak, true, true);
   }
-  return p;
 }
 
 Node* ZBarrierSetC2::atomic_cmpxchg_val_at_resolved(C2AtomicParseAccess& access, Node* expected_val,
                                                     Node* new_val, const Type* val_type) const {
   Node* result = BarrierSetC2::atomic_cmpxchg_val_at_resolved(access, expected_val, new_val, val_type);
-  LoadStoreNode* lsn = result->as_LoadStore();
-  if (barrier_needed(access)) {
-    lsn->set_has_barrier();
+  if (!barrier_needed(access)) {
+    return result;
   }
-  return lsn;
+
+  access.set_needs_pinning(false);
+  return make_cmpx_loadbarrier(access);
 }
 
 Node* ZBarrierSetC2::atomic_cmpxchg_bool_at_resolved(C2AtomicParseAccess& access, Node* expected_val,
                                                      Node* new_val, const Type* value_type) const {
   Node* result = BarrierSetC2::atomic_cmpxchg_bool_at_resolved(access, expected_val, new_val, value_type);
-  LoadStoreNode* lsn = result->as_LoadStore();
-  if (barrier_needed(access)) {
-    lsn->set_has_barrier();
+  if (!barrier_needed(access)) {
+    return result;
+  }
+
+  Node* load_store = access.raw_access();
+  bool weak_cas = (access.decorators() & C2_WEAK_CMPXCHG) != 0;
+  bool expected_is_null = (expected_val->get_ptr_type() == TypePtr::NULL_PTR);
+
+  if (!expected_is_null) {
+    if (weak_cas) {
+      access.set_needs_pinning(false);
+      load_store = make_cas_loadbarrier(access);
+    } else {
+      access.set_needs_pinning(false);
+      load_store = make_cas_loadbarrier(access);
+    }
   }
-  return lsn;
+
+  return load_store;
 }
 
 Node* ZBarrierSetC2::atomic_xchg_at_resolved(C2AtomicParseAccess& access, Node* new_val, const Type* val_type) const {
   Node* result = BarrierSetC2::atomic_xchg_at_resolved(access, new_val, val_type);
-  LoadStoreNode* lsn = result->as_LoadStore();
-  if (barrier_needed(access)) {
-    lsn->set_has_barrier();
+  if (!barrier_needed(access)) {
+    return result;
   }
-  return lsn;
+
+  Node* load_store = access.raw_access();
+  Node* adr = access.addr().node();
+
+  assert(access.is_parse_access(), "entry not supported at optimization time");
+  C2ParseAccess& parse_access = static_cast<C2ParseAccess&>(access);
+  return load_barrier(parse_access.kit(), load_store, adr, false, false, false);
 }
 
 // == Macro Expansion ==
 
-// Optimized, low spill, loadbarrier variant using stub specialized on register used
 void ZBarrierSetC2::expand_loadbarrier_node(PhaseMacroExpand* phase, LoadBarrierNode* barrier) const {
+  Node* in_ctrl = barrier->in(LoadBarrierNode::Control);
+  Node* in_mem  = barrier->in(LoadBarrierNode::Memory);
+  Node* in_val  = barrier->in(LoadBarrierNode::Oop);
+  Node* in_adr  = barrier->in(LoadBarrierNode::Address);
+
+  Node* out_ctrl = barrier->proj_out(LoadBarrierNode::Control);
+  Node* out_res  = barrier->proj_out(LoadBarrierNode::Oop);
+
   PhaseIterGVN &igvn = phase->igvn();
+
+  if (ZVerifyLoadBarriers) {
+    igvn.replace_node(out_res, in_val);
+    igvn.replace_node(out_ctrl, in_ctrl);
+    return;
+  }
+
+  if (barrier->can_be_eliminated()) {
+    // Clone and pin the load for this barrier below the dominating
+    // barrier: the load cannot be allowed to float above the
+    // dominating barrier
+    Node* load = in_val;
+
+    if (load->is_Load()) {
+      Node* new_load = load->clone();
+      Node* addp = new_load->in(MemNode::Address);
+      assert(addp->is_AddP() || addp->is_Phi() || addp->is_Load(), "bad address");
+      Node* cast = new CastPPNode(addp, igvn.type(addp), true);
+      Node* ctrl = NULL;
+      Node* similar = barrier->in(LoadBarrierNode::Similar);
+      if (similar->is_Phi()) {
+        // already expanded
+        ctrl = similar->in(0);
+      } else {
+        assert(similar->is_Proj() && similar->in(0)->is_LoadBarrier(), "unexpected graph shape");
+        ctrl = similar->in(0)->as_LoadBarrier()->proj_out(LoadBarrierNode::Control);
+      }
+      assert(ctrl != NULL, "bad control");
+      cast->set_req(0, ctrl);
+      igvn.transform(cast);
+      new_load->set_req(MemNode::Address, cast);
+      igvn.transform(new_load);
+
+      igvn.replace_node(out_res, new_load);
+      igvn.replace_node(out_ctrl, in_ctrl);
+      return;
+    }
+    // cannot eliminate
+  }
+
+  // There are two cases that require the basic loadbarrier
+  // 1) When the writeback of a healed oop must be avoided (swap)
+  // 2) When we must guarantee that no reload of is done (swap, cas, cmpx)
+  if (!barrier->is_writeback()) {
+    assert(!barrier->oop_reload_allowed(), "writeback barriers should be marked as requires oop");
+  }
+
+  if (!barrier->oop_reload_allowed()) {
+    expand_loadbarrier_basic(phase, barrier);
+  } else {
+    expand_loadbarrier_optimized(phase, barrier);
+  }
+}
+
+// Basic loadbarrier using conventional argument passing
+void ZBarrierSetC2::expand_loadbarrier_basic(PhaseMacroExpand* phase, LoadBarrierNode *barrier) const {
+  PhaseIterGVN &igvn = phase->igvn();
+
+  Node* in_ctrl = barrier->in(LoadBarrierNode::Control);
+  Node* in_mem  = barrier->in(LoadBarrierNode::Memory);
+  Node* in_val  = barrier->in(LoadBarrierNode::Oop);
+  Node* in_adr  = barrier->in(LoadBarrierNode::Address);
+
+  Node* out_ctrl = barrier->proj_out(LoadBarrierNode::Control);
+  Node* out_res  = barrier->proj_out(LoadBarrierNode::Oop);
+
   float unlikely  = PROB_UNLIKELY(0.999);
+  const Type* in_val_maybe_null_t = igvn.type(in_val);
+
+  Node* jthread = igvn.transform(new ThreadLocalNode());
+  Node* adr = phase->basic_plus_adr(jthread, in_bytes(ZThreadLocalData::address_bad_mask_offset()));
+  Node* bad_mask = igvn.transform(LoadNode::make(igvn, in_ctrl, in_mem, adr, TypeRawPtr::BOTTOM, TypeX_X, TypeX_X->basic_type(), MemNode::unordered));
+  Node* cast = igvn.transform(new CastP2XNode(in_ctrl, in_val));
+  Node* obj_masked = igvn.transform(new AndXNode(cast, bad_mask));
+  Node* cmp = igvn.transform(new CmpXNode(obj_masked, igvn.zerocon(TypeX_X->basic_type())));
+  Node *bol = igvn.transform(new BoolNode(cmp, BoolTest::ne))->as_Bool();
+  IfNode* iff = igvn.transform(new IfNode(in_ctrl, bol, unlikely, COUNT_UNKNOWN))->as_If();
+  Node* then = igvn.transform(new IfTrueNode(iff));
+  Node* elsen = igvn.transform(new IfFalseNode(iff));
+
+  Node* result_region;
+  Node* result_val;
+
+  result_region = new RegionNode(3);
+  result_val = new PhiNode(result_region, TypeInstPtr::BOTTOM);
+
+  result_region->set_req(1, elsen);
+  Node* res = igvn.transform(new CastPPNode(in_val, in_val_maybe_null_t));
+  res->init_req(0, elsen);
+  result_val->set_req(1, res);
+
+  const TypeFunc *tf = load_barrier_Type();
+  Node* call;
+  if (barrier->is_weak()) {
+    call = new CallLeafNode(tf,
+                            ZBarrierSetRuntime::load_barrier_on_weak_oop_field_preloaded_addr(),
+                            "ZBarrierSetRuntime::load_barrier_on_weak_oop_field_preloaded",
+                            TypeRawPtr::BOTTOM);
+  } else {
+    call = new CallLeafNode(tf,
+                            ZBarrierSetRuntime::load_barrier_on_oop_field_preloaded_addr(),
+                            "ZBarrierSetRuntime::load_barrier_on_oop_field_preloaded",
+                            TypeRawPtr::BOTTOM);
+  }
+
+  call->init_req(TypeFunc::Control, then);
+  call->init_req(TypeFunc::I_O    , phase->top());
+  call->init_req(TypeFunc::Memory , in_mem);
+  call->init_req(TypeFunc::FramePtr, phase->top());
+  call->init_req(TypeFunc::ReturnAdr, phase->top());
+  call->init_req(TypeFunc::Parms+0, in_val);
+  if (barrier->is_writeback()) {
+    call->init_req(TypeFunc::Parms+1, in_adr);
+  } else {
+    // When slow path is called with a null address, the healed oop will not be written back
+    call->init_req(TypeFunc::Parms+1, igvn.zerocon(T_OBJECT));
+  }
+  call = igvn.transform(call);
+
+  Node* ctrl = igvn.transform(new ProjNode(call, TypeFunc::Control));
+  res = igvn.transform(new ProjNode(call, TypeFunc::Parms));
+  res = igvn.transform(new CheckCastPPNode(ctrl, res, in_val_maybe_null_t));
+
+  result_region->set_req(2, ctrl);
+  result_val->set_req(2, res);
+
+  result_region = igvn.transform(result_region);
+  result_val = igvn.transform(result_val);
+
+  if (out_ctrl != NULL) { // Added if cond
+    igvn.replace_node(out_ctrl, result_region);
+  }
+  igvn.replace_node(out_res, result_val);
+}
+
+// Optimized, low spill, loadbarrier variant using stub specialized on register used
+void ZBarrierSetC2::expand_loadbarrier_optimized(PhaseMacroExpand* phase, LoadBarrierNode *barrier) const {
+  PhaseIterGVN &igvn = phase->igvn();
+#ifdef PRINT_NODE_TRAVERSALS
+  Node* preceding_barrier_node = barrier->in(LoadBarrierNode::Oop);
+#endif
 
   Node* in_ctrl = barrier->in(LoadBarrierNode::Control);
   Node* in_mem = barrier->in(LoadBarrierNode::Memory);
   Node* in_val = barrier->in(LoadBarrierNode::Oop);
   Node* in_adr = barrier->in(LoadBarrierNode::Address);
 
-  Node* out_ctrl = barrier->proj_out_or_null(LoadBarrierNode::Control);
+  Node* out_ctrl = barrier->proj_out(LoadBarrierNode::Control);
   Node* out_res = barrier->proj_out(LoadBarrierNode::Oop);
 
   assert(barrier->in(LoadBarrierNode::Oop) != NULL, "oop to loadbarrier node cannot be null");
 
+#ifdef PRINT_NODE_TRAVERSALS
+  tty->print("\n\n\nBefore barrier optimization:\n");
+  traverse(barrier, out_ctrl, out_res, -1);
+
+  tty->print("\nBefore barrier optimization:  preceding_barrier_node\n");
+  traverse(preceding_barrier_node, out_ctrl, out_res, -1);
+#endif
+
+  float unlikely  = PROB_UNLIKELY(0.999);
+
   Node* jthread = igvn.transform(new ThreadLocalNode());
   Node* adr = phase->basic_plus_adr(jthread, in_bytes(ZThreadLocalData::address_bad_mask_offset()));
   Node* bad_mask = igvn.transform(LoadNode::make(igvn, in_ctrl, in_mem, adr,
                                                  TypeRawPtr::BOTTOM, TypeX_X, TypeX_X->basic_type(),
                                                  MemNode::unordered));

@@ -538,44 +966,61 @@
   Node *bol = igvn.transform(new BoolNode(cmp, BoolTest::ne))->as_Bool();
   IfNode* iff = igvn.transform(new IfNode(in_ctrl, bol, unlikely, COUNT_UNKNOWN))->as_If();
   Node* then = igvn.transform(new IfTrueNode(iff));
   Node* elsen = igvn.transform(new IfFalseNode(iff));
 
-  Node* new_loadp = igvn.transform(new LoadBarrierSlowRegNode(then, in_mem, in_adr, in_val->adr_type(),
-                                                                    (const TypePtr*) in_val->bottom_type(), MemNode::unordered, barrier->is_weak()));
+  Node* slow_path_surrogate;
+  if (!barrier->is_weak()) {
+    slow_path_surrogate = igvn.transform(new LoadBarrierSlowRegNode(then, in_mem, in_adr, in_val->adr_type(),
+                                                                    (const TypePtr*) in_val->bottom_type(), MemNode::unordered));
+  } else {
+    slow_path_surrogate = igvn.transform(new LoadBarrierWeakSlowRegNode(then, in_mem, in_adr, in_val->adr_type(),
+                                                                        (const TypePtr*) in_val->bottom_type(), MemNode::unordered));
+  }
 
+  Node *new_loadp;
+  new_loadp = slow_path_surrogate;
   // Create the final region/phi pair to converge cntl/data paths to downstream code
   Node* result_region = igvn.transform(new RegionNode(3));
   result_region->set_req(1, then);
   result_region->set_req(2, elsen);
 
   Node* result_phi = igvn.transform(new PhiNode(result_region, TypeInstPtr::BOTTOM));
   result_phi->set_req(1, new_loadp);
   result_phi->set_req(2, barrier->in(LoadBarrierNode::Oop));
 
-  if (out_ctrl != NULL) {
+  // Finally, connect the original outputs to the barrier region and phi to complete the expansion/substitution
+  // igvn.replace_node(out_ctrl, result_region);
+  if (out_ctrl != NULL) { // added if cond
     igvn.replace_node(out_ctrl, result_region);
   }
   igvn.replace_node(out_res, result_phi);
 
   assert(barrier->outcnt() == 0,"LoadBarrier macro node has non-null outputs after expansion!");
 
-  igvn.remove_dead_node(barrier);
-  igvn.remove_dead_node(out_ctrl);
-  igvn.remove_dead_node(out_res);
+#ifdef PRINT_NODE_TRAVERSALS
+  tty->print("\nAfter barrier optimization:  old out_ctrl\n");
+  traverse(out_ctrl, out_ctrl, out_res, -1);
+  tty->print("\nAfter barrier optimization:  old out_res\n");
+  traverse(out_res, out_ctrl, out_res, -1);
+  tty->print("\nAfter barrier optimization:  old barrier\n");
+  traverse(barrier, out_ctrl, out_res, -1);
+  tty->print("\nAfter barrier optimization:  preceding_barrier_node\n");
+  traverse(preceding_barrier_node, result_region, result_phi, -1);
+#endif
 
   assert(is_gc_barrier_node(result_phi), "sanity");
   assert(step_over_gc_barrier(result_phi) == in_val, "sanity");
-
-  phase->C->print_method(PHASE_BARRIER_EXPANSION, 4, barrier->_idx);
 }
 
 bool ZBarrierSetC2::expand_barriers(Compile* C, PhaseIterGVN& igvn) const {
   ZBarrierSetC2State* s = state();
   if (s->load_barrier_count() > 0) {
     PhaseMacroExpand macro(igvn);
-
+#ifdef ASSERT
+    verify_gc_barriers(false);
+#endif
     int skipped = 0;
     while (s->load_barrier_count() > skipped) {
       int load_barrier_count = s->load_barrier_count();
       LoadBarrierNode * n = s->load_barrier_node(load_barrier_count-1-skipped);
       if (igvn.type(n) == Type::TOP || (n->in(0) != NULL && n->in(0)->is_top())) {

@@ -612,10 +1057,379 @@
   }
 
   return false;
 }
 
+// == Loop optimization ==
+
+static bool replace_with_dominating_barrier(PhaseIdealLoop* phase, LoadBarrierNode* lb, bool last_round) {
+  PhaseIterGVN &igvn = phase->igvn();
+  Compile* C = Compile::current();
+
+  LoadBarrierNode* lb2 = lb->has_dominating_barrier(phase, false, last_round);
+  if (lb2 == NULL) {
+    return false;
+  }
+
+  if (lb->in(LoadBarrierNode::Oop) != lb2->in(LoadBarrierNode::Oop)) {
+    assert(lb->in(LoadBarrierNode::Address) == lb2->in(LoadBarrierNode::Address), "Invalid address");
+    igvn.replace_input_of(lb, LoadBarrierNode::Similar, lb2->proj_out(LoadBarrierNode::Oop));
+    C->set_major_progress();
+    return false;
+  }
+
+  // That transformation may cause the Similar edge on dominated load barriers to be invalid
+  lb->fix_similar_in_uses(&igvn);
+
+  Node* val = lb->proj_out(LoadBarrierNode::Oop);
+  assert(lb2->has_true_uses(), "Invalid uses");
+  assert(lb2->in(LoadBarrierNode::Oop) == lb->in(LoadBarrierNode::Oop), "Invalid oop");
+  phase->lazy_update(lb, lb->in(LoadBarrierNode::Control));
+  phase->lazy_replace(lb->proj_out(LoadBarrierNode::Control), lb->in(LoadBarrierNode::Control));
+  igvn.replace_node(val, lb2->proj_out(LoadBarrierNode::Oop));
+
+  return true;
+}
+
+static Node* find_dominating_memory(PhaseIdealLoop* phase, Node* mem, Node* dom, int i) {
+  assert(dom->is_Region() || i == -1, "");
+
+  Node* m = mem;
+  while(phase->is_dominator(dom, phase->has_ctrl(m) ? phase->get_ctrl(m) : m->in(0))) {
+    if (m->is_Mem()) {
+      assert(m->as_Mem()->adr_type() == TypeRawPtr::BOTTOM, "");
+      m = m->in(MemNode::Memory);
+    } else if (m->is_MergeMem()) {
+      m = m->as_MergeMem()->memory_at(Compile::AliasIdxRaw);
+    } else if (m->is_Phi()) {
+      if (m->in(0) == dom && i != -1) {
+        m = m->in(i);
+        break;
+      } else {
+        m = m->in(LoopNode::EntryControl);
+      }
+    } else if (m->is_Proj()) {
+      m = m->in(0);
+    } else if (m->is_SafePoint() || m->is_MemBar()) {
+      m = m->in(TypeFunc::Memory);
+    } else {
+#ifdef ASSERT
+      m->dump();
+#endif
+      ShouldNotReachHere();
+    }
+  }
+
+  return m;
+}
+
+static LoadBarrierNode* clone_load_barrier(PhaseIdealLoop* phase, LoadBarrierNode* lb, Node* ctl, Node* mem, Node* oop_in) {
+  PhaseIterGVN &igvn = phase->igvn();
+  Compile* C = Compile::current();
+  Node* the_clone = lb->clone();
+  the_clone->set_req(LoadBarrierNode::Control, ctl);
+  the_clone->set_req(LoadBarrierNode::Memory, mem);
+  if (oop_in != NULL) {
+    the_clone->set_req(LoadBarrierNode::Oop, oop_in);
+  }
+
+  LoadBarrierNode* new_lb = the_clone->as_LoadBarrier();
+  igvn.register_new_node_with_optimizer(new_lb);
+  IdealLoopTree *loop = phase->get_loop(new_lb->in(0));
+  phase->set_ctrl(new_lb, new_lb->in(0));
+  phase->set_loop(new_lb, loop);
+  phase->set_idom(new_lb, new_lb->in(0), phase->dom_depth(new_lb->in(0))+1);
+  if (!loop->_child) {
+    loop->_body.push(new_lb);
+  }
+
+  Node* proj_ctl = new ProjNode(new_lb, LoadBarrierNode::Control);
+  igvn.register_new_node_with_optimizer(proj_ctl);
+  phase->set_ctrl(proj_ctl, proj_ctl->in(0));
+  phase->set_loop(proj_ctl, loop);
+  phase->set_idom(proj_ctl, new_lb, phase->dom_depth(new_lb)+1);
+  if (!loop->_child) {
+    loop->_body.push(proj_ctl);
+  }
+
+  Node* proj_oop = new ProjNode(new_lb, LoadBarrierNode::Oop);
+  phase->register_new_node(proj_oop, new_lb);
+
+  if (!new_lb->in(LoadBarrierNode::Similar)->is_top()) {
+    LoadBarrierNode* similar = new_lb->in(LoadBarrierNode::Similar)->in(0)->as_LoadBarrier();
+    if (!phase->is_dominator(similar, ctl)) {
+      igvn.replace_input_of(new_lb, LoadBarrierNode::Similar, C->top());
+    }
+  }
+
+  return new_lb;
+}
+
+static void replace_barrier(PhaseIdealLoop* phase, LoadBarrierNode* lb, Node* new_val) {
+  PhaseIterGVN &igvn = phase->igvn();
+  Node* val = lb->proj_out(LoadBarrierNode::Oop);
+  igvn.replace_node(val, new_val);
+  phase->lazy_update(lb, lb->in(LoadBarrierNode::Control));
+  phase->lazy_replace(lb->proj_out(LoadBarrierNode::Control), lb->in(LoadBarrierNode::Control));
+}
+
+static bool split_barrier_thru_phi(PhaseIdealLoop* phase, LoadBarrierNode* lb) {
+  PhaseIterGVN &igvn = phase->igvn();
+  Compile* C = Compile::current();
+
+  if (lb->in(LoadBarrierNode::Oop)->is_Phi()) {
+    Node* oop_phi = lb->in(LoadBarrierNode::Oop);
+
+    if ((oop_phi->req() != 3) || (oop_phi->in(2) == oop_phi)) {
+      // Ignore phis with only one input
+      return false;
+    }
+
+    if (phase->is_dominator(phase->get_ctrl(lb->in(LoadBarrierNode::Address)),
+                            oop_phi->in(0)) && phase->get_ctrl(lb->in(LoadBarrierNode::Address)) != oop_phi->in(0)) {
+      // That transformation may cause the Similar edge on dominated load barriers to be invalid
+      lb->fix_similar_in_uses(&igvn);
+
+      RegionNode* region = oop_phi->in(0)->as_Region();
+
+      int backedge = LoopNode::LoopBackControl;
+      if (region->is_Loop() && region->in(backedge)->is_Proj() && region->in(backedge)->in(0)->is_If()) {
+        Node* c = region->in(backedge)->in(0)->in(0);
+        assert(c->unique_ctrl_out() == region->in(backedge)->in(0), "");
+        Node* oop = lb->in(LoadBarrierNode::Oop)->in(backedge);
+        Node* oop_c = phase->has_ctrl(oop) ? phase->get_ctrl(oop) : oop;
+        if (!phase->is_dominator(oop_c, c)) {
+          return false;
+        }
+      }
+
+      // If the node on the backedge above the phi is the node itself - we have a self loop.
+      // Don't clone - this will be folded later.
+      if (oop_phi->in(LoopNode::LoopBackControl) == lb->proj_out(LoadBarrierNode::Oop)) {
+        return false;
+      }
+
+      bool is_strip_mined = region->is_CountedLoop() && region->as_CountedLoop()->is_strip_mined();
+      Node *phi = oop_phi->clone();
+
+      for (uint i = 1; i < region->req(); i++) {
+        Node* ctrl = region->in(i);
+        if (ctrl != C->top()) {
+          assert(!phase->is_dominator(ctrl, region) || region->is_Loop(), "");
+
+          Node* mem = lb->in(LoadBarrierNode::Memory);
+          Node* m = find_dominating_memory(phase, mem, region, i);
+
+          if (region->is_Loop() && i == LoopNode::LoopBackControl && ctrl->is_Proj() && ctrl->in(0)->is_If()) {
+            ctrl = ctrl->in(0)->in(0);
+          } else if (region->is_Loop() && is_strip_mined) {
+            // If this is a strip mined loop, control must move above OuterStripMinedLoop
+            assert(i == LoopNode::EntryControl, "check");
+            assert(ctrl->is_OuterStripMinedLoop(), "sanity");
+            ctrl = ctrl->as_OuterStripMinedLoop()->in(LoopNode::EntryControl);
+          }
+
+          LoadBarrierNode* new_lb = clone_load_barrier(phase, lb, ctrl, m, lb->in(LoadBarrierNode::Oop)->in(i));
+          Node* out_ctrl = new_lb->proj_out(LoadBarrierNode::Control);
+
+          if (is_strip_mined && (i == LoopNode::EntryControl)) {
+            assert(region->in(i)->is_OuterStripMinedLoop(), "");
+            igvn.replace_input_of(region->in(i), i, out_ctrl);
+            phase->set_idom(region->in(i), out_ctrl, phase->dom_depth(out_ctrl));
+          } else if (ctrl == region->in(i)) {
+            igvn.replace_input_of(region, i, out_ctrl);
+            // Only update the idom if is the loop entry we are updating
+            // - A loop backedge doesn't change the idom
+            if (region->is_Loop() && i == LoopNode::EntryControl) {
+              phase->set_idom(region, out_ctrl, phase->dom_depth(out_ctrl));
+            }
+          } else {
+            Node* iff = region->in(i)->in(0);
+            igvn.replace_input_of(iff, 0, out_ctrl);
+            phase->set_idom(iff, out_ctrl, phase->dom_depth(out_ctrl)+1);
+          }
+          phi->set_req(i, new_lb->proj_out(LoadBarrierNode::Oop));
+        }
+      }
+      phase->register_new_node(phi, region);
+      replace_barrier(phase, lb, phi);
+
+      if (region->is_Loop()) {
+        // Load barrier moved to the back edge of the Loop may now
+        // have a safepoint on the path to the barrier on the Similar
+        // edge
+        igvn.replace_input_of(phi->in(LoopNode::LoopBackControl)->in(0), LoadBarrierNode::Similar, C->top());
+        Node* head = region->in(LoopNode::EntryControl);
+        phase->set_idom(region, head, phase->dom_depth(head)+1);
+        phase->recompute_dom_depth();
+        if (head->is_CountedLoop() && head->as_CountedLoop()->is_main_loop()) {
+          head->as_CountedLoop()->set_normal_loop();
+        }
+      }
+
+      return true;
+    }
+  }
+
+  return false;
+}
+
+static bool move_out_of_loop(PhaseIdealLoop* phase, LoadBarrierNode* lb) {
+  PhaseIterGVN &igvn = phase->igvn();
+  IdealLoopTree *lb_loop = phase->get_loop(lb->in(0));
+  if (lb_loop != phase->ltree_root() && !lb_loop->_irreducible) {
+    Node* oop_ctrl = phase->get_ctrl(lb->in(LoadBarrierNode::Oop));
+    IdealLoopTree *oop_loop = phase->get_loop(oop_ctrl);
+    IdealLoopTree* adr_loop = phase->get_loop(phase->get_ctrl(lb->in(LoadBarrierNode::Address)));
+    if (!lb_loop->is_member(oop_loop) && !lb_loop->is_member(adr_loop)) {
+      // That transformation may cause the Similar edge on dominated load barriers to be invalid
+      lb->fix_similar_in_uses(&igvn);
+
+      Node* head = lb_loop->_head;
+      assert(head->is_Loop(), "");
+
+      if (phase->is_dominator(head, oop_ctrl)) {
+        assert(oop_ctrl->Opcode() == Op_CProj && oop_ctrl->in(0)->Opcode() == Op_NeverBranch, "");
+        assert(lb_loop->is_member(phase->get_loop(oop_ctrl->in(0)->in(0))), "");
+        return false;
+      }
+
+      if (head->is_CountedLoop()) {
+        CountedLoopNode* cloop = head->as_CountedLoop();
+        if (cloop->is_main_loop()) {
+          cloop->set_normal_loop();
+        }
+        // When we are moving barrier out of a counted loop,
+        // make sure we move it all the way out of the strip mined outer loop.
+        if (cloop->is_strip_mined()) {
+          head = cloop->outer_loop();
+        }
+      }
+
+      Node* mem = lb->in(LoadBarrierNode::Memory);
+      Node* m = find_dominating_memory(phase, mem, head, -1);
+
+      LoadBarrierNode* new_lb = clone_load_barrier(phase, lb, head->in(LoopNode::EntryControl), m, NULL);
+
+      assert(phase->idom(head) == head->in(LoopNode::EntryControl), "");
+      Node* proj_ctl = new_lb->proj_out(LoadBarrierNode::Control);
+      igvn.replace_input_of(head, LoopNode::EntryControl, proj_ctl);
+      phase->set_idom(head, proj_ctl, phase->dom_depth(proj_ctl) + 1);
+
+      replace_barrier(phase, lb, new_lb->proj_out(LoadBarrierNode::Oop));
+
+      phase->recompute_dom_depth();
+
+      return true;
+    }
+  }
+
+  return false;
+}
+
+static bool common_barriers(PhaseIdealLoop* phase, LoadBarrierNode* lb) {
+  PhaseIterGVN &igvn = phase->igvn();
+  Node* in_val = lb->in(LoadBarrierNode::Oop);
+  for (DUIterator_Fast imax, i = in_val->fast_outs(imax); i < imax; i++) {
+    Node* u = in_val->fast_out(i);
+    if (u != lb && u->is_LoadBarrier() && u->as_LoadBarrier()->has_true_uses()) {
+      Node* this_ctrl = lb->in(LoadBarrierNode::Control);
+      Node* other_ctrl = u->in(LoadBarrierNode::Control);
+
+      Node* lca = phase->dom_lca(this_ctrl, other_ctrl);
+      bool ok = true;
+
+      Node* proj1 = NULL;
+      Node* proj2 = NULL;
+
+      while (this_ctrl != lca && ok) {
+        if (this_ctrl->in(0) != NULL &&
+            this_ctrl->in(0)->is_MultiBranch()) {
+          if (this_ctrl->in(0)->in(0) == lca) {
+            assert(proj1 == NULL, "");
+            assert(this_ctrl->is_Proj(), "");
+            proj1 = this_ctrl;
+          } else if (!(this_ctrl->in(0)->is_If() && this_ctrl->as_Proj()->is_uncommon_trap_if_pattern(Deoptimization::Reason_none))) {
+            ok = false;
+          }
+        }
+        this_ctrl = phase->idom(this_ctrl);
+      }
+      while (other_ctrl != lca && ok) {
+        if (other_ctrl->in(0) != NULL &&
+            other_ctrl->in(0)->is_MultiBranch()) {
+          if (other_ctrl->in(0)->in(0) == lca) {
+            assert(other_ctrl->is_Proj(), "");
+            assert(proj2 == NULL, "");
+            proj2 = other_ctrl;
+          } else if (!(other_ctrl->in(0)->is_If() && other_ctrl->as_Proj()->is_uncommon_trap_if_pattern(Deoptimization::Reason_none))) {
+            ok = false;
+          }
+        }
+        other_ctrl = phase->idom(other_ctrl);
+      }
+      assert(proj1 == NULL || proj2 == NULL || proj1->in(0) == proj2->in(0), "");
+      if (ok && proj1 && proj2 && proj1 != proj2 && proj1->in(0)->is_If()) {
+        // That transformation may cause the Similar edge on dominated load barriers to be invalid
+        lb->fix_similar_in_uses(&igvn);
+        u->as_LoadBarrier()->fix_similar_in_uses(&igvn);
+
+        Node* split = lca->unique_ctrl_out();
+        assert(split->in(0) == lca, "");
+
+        Node* mem = lb->in(LoadBarrierNode::Memory);
+        Node* m = find_dominating_memory(phase, mem, split, -1);
+        LoadBarrierNode* new_lb = clone_load_barrier(phase, lb, lca, m, NULL);
+
+        Node* proj_ctl = new_lb->proj_out(LoadBarrierNode::Control);
+        igvn.replace_input_of(split, 0, new_lb->proj_out(LoadBarrierNode::Control));
+        phase->set_idom(split, proj_ctl, phase->dom_depth(proj_ctl)+1);
+
+        Node* proj_oop = new_lb->proj_out(LoadBarrierNode::Oop);
+        replace_barrier(phase, lb, proj_oop);
+        replace_barrier(phase, u->as_LoadBarrier(), proj_oop);
+
+        phase->recompute_dom_depth();
+
+        return true;
+      }
+    }
+  }
+
+  return false;
+}
+
+void ZBarrierSetC2::loop_optimize_gc_barrier(PhaseIdealLoop* phase, Node* node, bool last_round) {
+  if (!Compile::current()->directive()->ZOptimizeLoadBarriersOption) {
+    return;
+  }
+
+  if (!node->is_LoadBarrier()) {
+    return;
+  }
+
+  if (!node->as_LoadBarrier()->has_true_uses()) {
+    return;
+  }
+
+  if (replace_with_dominating_barrier(phase, node->as_LoadBarrier(), last_round)) {
+    return;
+  }
+
+  if (split_barrier_thru_phi(phase, node->as_LoadBarrier())) {
+    return;
+  }
+
+  if (move_out_of_loop(phase, node->as_LoadBarrier())) {
+    return;
+  }
+
+  if (common_barriers(phase, node->as_LoadBarrier())) {
+    return;
+  }
+}
+
 Node* ZBarrierSetC2::step_over_gc_barrier(Node* c) const {
   Node* node = c;
 
   // 1. This step follows potential oop projections of a load barrier before expansion
   if (node->is_Proj()) {

@@ -629,11 +1443,11 @@
 
   // 3. This step checks for the phi corresponding to an optimized load barrier expansion
   if (node->is_Phi()) {
     PhiNode* phi = node->as_Phi();
     Node* n = phi->in(1);
-    if (n != NULL && n->is_LoadBarrierSlowReg()) {
+    if (n != NULL && (n->is_LoadBarrierSlowReg() ||  n->is_LoadBarrierWeakSlowReg())) {
       assert(c == node, "projections from step 1 should only be seen before macro expansion");
       return phi->in(2);
     }
   }
 

@@ -643,80 +1457,39 @@
 bool ZBarrierSetC2::array_copy_requires_gc_barriers(bool tightly_coupled_alloc, BasicType type, bool is_clone, ArrayCopyPhase phase) const {
   return type == T_OBJECT || type == T_ARRAY;
 }
 
 bool ZBarrierSetC2::final_graph_reshaping(Compile* compile, Node* n, uint opcode) const {
-  switch (opcode) {
-    case Op_LoadBarrier:
-      assert(0, "There should be no load barriers left");
-    case Op_ZGetAndSetP:
-    case Op_ZCompareAndExchangeP:
-    case Op_ZCompareAndSwapP:
-    case Op_ZWeakCompareAndSwapP:
-    case Op_LoadBarrierSlowReg:
+  if (opcode != Op_LoadBarrierSlowReg &&
+      opcode != Op_LoadBarrierWeakSlowReg) {
+    return false;
+  }
+
 #ifdef ASSERT
-      if (VerifyOptoOopOffsets) {
-        MemNode *mem = n->as_Mem();
-        // Check to see if address types have grounded out somehow.
-        const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
-        ciInstanceKlass *k = tp->klass()->as_instance_klass();
-        bool oop_offset_is_sane = k->contains_field_offset(tp->offset());
-        assert(!tp || oop_offset_is_sane, "");
-      }
-#endif
-      return true;
-    default:
-      return false;
+  if (VerifyOptoOopOffsets) {
+    MemNode* mem  = n->as_Mem();
+    // Check to see if address types have grounded out somehow.
+    const TypeInstPtr* tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
+    ciInstanceKlass* k = tp->klass()->as_instance_klass();
+    bool oop_offset_is_sane = k->contains_field_offset(tp->offset());
+    assert(!tp || oop_offset_is_sane, "");
   }
+#endif
+
+  return true;
 }
 
 bool ZBarrierSetC2::matcher_find_shared_visit(Matcher* matcher, Matcher::MStack& mstack, Node* n, uint opcode, bool& mem_op, int& mem_addr_idx) const {
-  switch(opcode) {
-    case Op_CallLeaf:
-      if (n->as_Call()->entry_point() == ZBarrierSetRuntime::load_barrier_on_oop_field_preloaded_addr() ||
-          n->as_Call()->entry_point() == ZBarrierSetRuntime::load_barrier_on_weak_oop_field_preloaded_addr()) {
-        mem_op = true;
-        mem_addr_idx = TypeFunc::Parms + 1;
-        return true;
-      }
-      return false;
-    default:
-      return false;
+  if (opcode == Op_CallLeaf &&
+      (n->as_Call()->entry_point() == ZBarrierSetRuntime::load_barrier_on_oop_field_preloaded_addr() ||
+       n->as_Call()->entry_point() == ZBarrierSetRuntime::load_barrier_on_weak_oop_field_preloaded_addr())) {
+    mem_op = true;
+    mem_addr_idx = TypeFunc::Parms + 1;
+    return true;
   }
-}
 
-bool ZBarrierSetC2::matcher_find_shared_post_visit(Matcher* matcher, Node* n, uint opcode) const {
-  switch(opcode) {
-    case Op_ZCompareAndExchangeP:
-    case Op_ZCompareAndSwapP:
-    case Op_ZWeakCompareAndSwapP: {
-      Node *mem = n->in(MemNode::Address);
-      Node *keepalive = n->in(5);
-      Node *pair1 = new BinaryNode(mem, keepalive);
-
-      Node *newval = n->in(MemNode::ValueIn);
-      Node *oldval = n->in(LoadStoreConditionalNode::ExpectedIn);
-      Node *pair2 = new BinaryNode(oldval, newval);
-
-      n->set_req(MemNode::Address, pair1);
-      n->set_req(MemNode::ValueIn, pair2);
-      n->del_req(5);
-      n->del_req(LoadStoreConditionalNode::ExpectedIn);
-      return true;
-    }
-    case Op_ZGetAndSetP: {
-      Node *keepalive = n->in(4);
-      Node *newval = n->in(MemNode::ValueIn);
-      Node *pair = new BinaryNode(newval, keepalive);
-      n->set_req(MemNode::ValueIn, pair);
-      n->del_req(4);
-      return true;
-    }
-
-    default:
-      return false;
-  }
+  return false;
 }
 
 // == Verification ==
 
 #ifdef ASSERT

@@ -745,36 +1518,20 @@
 
   return true;
 }
 
 void ZBarrierSetC2::verify_gc_barriers(Compile* compile, CompilePhase phase) const {
-  switch(phase) {
-    case BarrierSetC2::BeforeOptimize:
-    case BarrierSetC2::BeforeLateInsertion:
-      assert(state()->load_barrier_count() == 0, "No barriers inserted yet");
-      break;
-    case BarrierSetC2::BeforeMacroExpand:
-      // Barrier placement should be set by now.
-      verify_gc_barriers(false /*post_parse*/);
-      break;
-    case BarrierSetC2::BeforeCodeGen:
-      // Barriers has been fully expanded.
-      assert(state()->load_barrier_count() == 0, "No more macro barriers");
-      break;
-    default:
-      assert(0, "Phase without verification");
-  }
+  if (phase == BarrierSetC2::BeforeCodeGen) return;
+  bool post_parse = phase == BarrierSetC2::BeforeOptimize;
+  verify_gc_barriers(post_parse);
 }
 
-// post_parse implies that there might be load barriers without uses after parsing
-// That only applies when adding barriers at parse time.
 void ZBarrierSetC2::verify_gc_barriers(bool post_parse) const {
   ZBarrierSetC2State* s = state();
   Compile* C = Compile::current();
   ResourceMark rm;
   VectorSet visited(Thread::current()->resource_area());
-
   for (int i = 0; i < s->load_barrier_count(); i++) {
     LoadBarrierNode* n = s->load_barrier_node(i);
 
     // The dominating barrier on the same address if it exists and
     // this barrier must not be applied on the value from the same

@@ -784,11 +1541,11 @@
            (n->in(LoadBarrierNode::Similar)->in(0)->is_LoadBarrier() &&
             n->in(LoadBarrierNode::Similar)->in(0)->in(LoadBarrierNode::Address) == n->in(LoadBarrierNode::Address) &&
             n->in(LoadBarrierNode::Similar)->in(0)->in(LoadBarrierNode::Oop) != n->in(LoadBarrierNode::Oop)),
            "broken similar edge");
 
-    assert(n->as_LoadBarrier()->has_true_uses(),
+    assert(post_parse || n->as_LoadBarrier()->has_true_uses(),
            "found unneeded load barrier");
 
     // Several load barrier nodes chained through their Similar edge
     // break the code that remove the barriers in final graph reshape.
     assert(n->in(LoadBarrierNode::Similar)->is_top() ||

@@ -799,835 +1556,89 @@
     if (!n->in(LoadBarrierNode::Similar)->is_top()) {
       ResourceMark rm;
       Unique_Node_List wq;
       Node* other = n->in(LoadBarrierNode::Similar)->in(0);
       wq.push(n);
+      bool ok = true;
+      bool dom_found = false;
       for (uint next = 0; next < wq.size(); ++next) {
-        Node *nn = wq.at(next);
-        assert(nn->is_CFG(), "");
-        assert(!nn->is_SafePoint(), "");
+        Node *n = wq.at(next);
+        assert(n->is_CFG(), "");
+        assert(!n->is_SafePoint(), "");
 
-        if (nn == other) {
+        if (n == other) {
           continue;
         }
 
-        if (nn->is_Region()) {
-          for (uint i = 1; i < nn->req(); i++) {
-            Node* m = nn->in(i);
+        if (n->is_Region()) {
+          for (uint i = 1; i < n->req(); i++) {
+            Node* m = n->in(i);
             if (m != NULL) {
               wq.push(m);
             }
           }
         } else {
-          Node* m = nn->in(0);
+          Node* m = n->in(0);
           if (m != NULL) {
             wq.push(m);
           }
         }
       }
     }
-  }
-}
-
-#endif // end verification code
-
-static void call_catch_cleanup_one(PhaseIdealLoop* phase, LoadNode* load, Node* ctrl);
-
-// This code is cloning all uses of a load that is between a call and the catch blocks,
-// to each use.
-
-static bool fixup_uses_in_catch(PhaseIdealLoop *phase, Node *start_ctrl, Node *node) {
-
-  if (!phase->has_ctrl(node)) {
-    // This node is floating - doesn't need to be cloned.
-    assert(node != start_ctrl, "check");
-    return false;
-  }
-
-  Node* ctrl = phase->get_ctrl(node);
-  if (ctrl != start_ctrl) {
-    // We are in a successor block - the node is ok.
-    return false; // Unwind
-  }
-
-  // Process successor nodes
-  int outcnt = node->outcnt();
-  for (int i = 0; i < outcnt; i++) {
-    Node* n = node->raw_out(0);
-    assert(!n->is_LoadBarrier(), "Sanity");
-    // Calling recursively, visiting leafs first
-    fixup_uses_in_catch(phase, start_ctrl, n);
-  }
-
-  // Now all successors are outside
-  // - Clone this node to both successors
-  int no_succs = node->outcnt();
-  assert(!node->is_Store(), "Stores not expected here");
-
-  // In some very rare cases a load that doesn't need a barrier will end up here
-  // Treat it as a LoadP and the insertion of phis will be done correctly.
-  if (node->is_Load()) {
-    call_catch_cleanup_one(phase, node->as_Load(), phase->get_ctrl(node));
-  } else {
-    for (DUIterator_Fast jmax, i = node->fast_outs(jmax); i < jmax; i++) {
-      Node* use = node->fast_out(i);
-      Node* clone = node->clone();
-      assert(clone->outcnt() == 0, "");
-
-      assert(use->find_edge(node) != -1, "check");
-      phase->igvn().rehash_node_delayed(use);
-      use->replace_edge(node, clone);
-
-      Node* new_ctrl;
-      if (use->is_block_start()) {
-        new_ctrl = use;
-      } else if (use->is_CFG()) {
-        new_ctrl = use->in(0);
-        assert (new_ctrl != NULL, "");
-      } else {
-        new_ctrl = phase->get_ctrl(use);
-      }
-
-      phase->set_ctrl(clone, new_ctrl);
-
-      if (phase->C->directive()->ZTraceLoadBarriersOption) tty->print_cr("  Clone op %i as %i to control %i", node->_idx, clone->_idx, new_ctrl->_idx);
-      phase->igvn().register_new_node_with_optimizer(clone);
-      --i, --jmax;
-    }
-    assert(node->outcnt() == 0, "must be empty now");
-
-    // Node node is dead.
-    phase->igvn().remove_dead_node(node);
-  }
-  return true; // unwind - return if a use was processed
-}
-
-// Clone a load to a specific catch_proj
-static Node* clone_load_to_catchproj(PhaseIdealLoop* phase, Node* load, Node* catch_proj) {
-  Node* cloned_load = load->clone();
-  cloned_load->set_req(0, catch_proj);      // set explicit control
-  phase->set_ctrl(cloned_load, catch_proj); // update
-  if (phase->C->directive()->ZTraceLoadBarriersOption) tty->print_cr("  Clone LOAD %i as %i to control %i", load->_idx, cloned_load->_idx, catch_proj->_idx);
-  phase->igvn().register_new_node_with_optimizer(cloned_load);
-  return cloned_load;
-}
-
-static Node* get_dominating_region(PhaseIdealLoop* phase, Node* node, Node* stop) {
-  Node* region = node;
-  while (!region->isa_Region()) {
-    Node *up = phase->idom(region);
-    assert(up != region, "Must not loop");
-    assert(up != stop,   "Must not find original control");
-    region = up;
-  }
-  return region;
-}
-
-// Clone this load to each catch block
-static void call_catch_cleanup_one(PhaseIdealLoop* phase, LoadNode* load, Node* ctrl) {
-  bool trace = phase->C->directive()->ZTraceLoadBarriersOption;
-  phase->igvn().set_delay_transform(true);
-
-  // Verify pre conditions
-  assert(ctrl->isa_Proj() && ctrl->in(0)->isa_Call(), "Must be a call proj");
-  assert(ctrl->raw_out(0)->isa_Catch(), "Must be a catch");
 
-  if (ctrl->raw_out(0)->isa_Catch()->outcnt() == 1) {
-    if (trace) tty->print_cr("Cleaning up catch: Skipping load %i, call with single catch", load->_idx);
-    return;
-  }
-
-  // Process the loads successor nodes - if any is between
-  // the call and the catch blocks, they need to be cloned to.
-  // This is done recursively
-  int outcnt = load->outcnt();
-  uint index = 0;
-  for (int i = 0; i < outcnt; i++) {
-    if (index < load->outcnt()) {
-      Node *n = load->raw_out(index);
-      assert(!n->is_LoadBarrier(), "Sanity");
-      if (!fixup_uses_in_catch(phase, ctrl, n)) {
-        // if no successor was cloned, progress to next out.
-        index++;
-      }
-    }
-  }
-
-  // Now all the loads uses has been cloned down
-  // Only thing left is to clone the loads, but they must end up
-  // first in the catch blocks.
-
-  // We clone the loads oo the catch blocks only when needed.
-  // An array is used to map the catch blocks to each lazily cloned load.
-  // In that way no extra unnecessary loads are cloned.
-
-  // Any use dominated by original block must have an phi and a region added
-
-  Node* catch_node = ctrl->raw_out(0);
-  int number_of_catch_projs = catch_node->outcnt();
-  Node** proj_to_load_mapping = NEW_RESOURCE_ARRAY(Node*, number_of_catch_projs);
-  Copy::zero_to_bytes(proj_to_load_mapping, sizeof(Node*) * number_of_catch_projs);
-
-  // The phi_map is used to keep track of where phis have already been inserted
-  int phi_map_len = phase->C->unique();
-  Node** phi_map = NEW_RESOURCE_ARRAY(Node*, phi_map_len);
-  Copy::zero_to_bytes(phi_map, sizeof(Node*) * phi_map_len);
-
-  for (unsigned int i = 0; i  < load->outcnt(); i++) {
-    Node* load_use_control = NULL;
-    Node* load_use = load->raw_out(i);
-
-    if (phase->has_ctrl(load_use)) {
-      load_use_control = phase->get_ctrl(load_use);
-    } else {
-      load_use_control = load_use->in(0);
-    }
-    assert(load_use_control != NULL, "sanity");
-    if (trace) tty->print_cr("  Handling use: %i, with control: %i", load_use->_idx, load_use_control->_idx);
-
-    // Some times the loads use is a phi. For them we need to determine from which catch block
-    // the use is defined.
-    bool load_use_is_phi = false;
-    unsigned int load_use_phi_index = 0;
-    Node* phi_ctrl = NULL;
-    if (load_use->is_Phi()) {
-      // Find phi input that matches load
-      for (unsigned int u = 1; u < load_use->req(); u++) {
-        if (load_use->in(u) == load) {
-          load_use_is_phi = true;
-          load_use_phi_index = u;
-          assert(load_use->in(0)->is_Region(), "Region or broken");
-          phi_ctrl = load_use->in(0)->in(u);
-          assert(phi_ctrl->is_CFG(), "check");
-          assert(phi_ctrl != load,   "check");
-          break;
-        }
-      }
-      assert(load_use_is_phi,        "must find");
-      assert(load_use_phi_index > 0, "sanity");
-    }
-
-    // For each load use, see which catch projs dominates, create load clone lazily and reconnect
-    bool found_dominating_catchproj = false;
-    for (int c = 0; c < number_of_catch_projs; c++) {
-      Node* catchproj = catch_node->raw_out(c);
-      assert(catchproj != NULL && catchproj->isa_CatchProj(), "Sanity");
-
-      if (!phase->is_dominator(catchproj, load_use_control)) {
-        if (load_use_is_phi && phase->is_dominator(catchproj, phi_ctrl)) {
-          // The loads use is local to the catchproj.
-          // fall out and replace load with catch-local load clone.
-        } else {
-          continue;
+    if (ZVerifyLoadBarriers) {
+      if ((n->is_Load() || n->is_LoadStore()) && n->bottom_type()->make_oopptr() != NULL) {
+        visited.Clear();
+        bool found = look_for_barrier(n, post_parse, visited);
+        if (!found) {
+          n->dump(1);
+          n->dump(-3);
+          stringStream ss;
+          C->method()->print_short_name(&ss);
+          tty->print_cr("-%s-", ss.as_string());
+          assert(found, "");
         }
       }
-      assert(!found_dominating_catchproj, "Max one should match");
-
-      // Clone loads to catch projs
-      Node* load_clone = proj_to_load_mapping[c];
-      if (load_clone == NULL) {
-        load_clone = clone_load_to_catchproj(phase, load, catchproj);
-        proj_to_load_mapping[c] = load_clone;
-      }
-      phase->igvn().rehash_node_delayed(load_use);
-
-      if (load_use_is_phi) {
-        // phis are special - the load is defined from a specific control flow
-        load_use->set_req(load_use_phi_index, load_clone);
-      } else {
-        // Multipe edges can be replaced at once - on calls for example
-        load_use->replace_edge(load, load_clone);
-      }
-      --i; // more than one edge can have been removed, but the next is in later iterations
-
-      // We could break the for-loop after finding a dominating match.
-      // But keep iterating to catch any bad idom early.
-      found_dominating_catchproj = true;
-    }
-
-    // We found no single catchproj that dominated the use - The use is at a point after
-    // where control flow from multiple catch projs have merged. We will have to create
-    // phi nodes before the use and tie the output from the cloned loads together. It
-    // can be a single phi or a number of chained phis, depending on control flow
-    if (!found_dominating_catchproj) {
-
-      // Use phi-control if use is a phi
-      if (load_use_is_phi) {
-        load_use_control = phi_ctrl;
-      }
-      assert(phase->is_dominator(ctrl, load_use_control), "Common use but no dominator");
-
-      // Clone a load on all paths
-      for (int c = 0; c < number_of_catch_projs; c++) {
-        Node* catchproj = catch_node->raw_out(c);
-        Node* load_clone = proj_to_load_mapping[c];
-        if (load_clone == NULL) {
-          load_clone = clone_load_to_catchproj(phase, load, catchproj);
-          proj_to_load_mapping[c] = load_clone;
-        }
-      }
-
-      // Move up dominator tree from use until dom front is reached
-      Node* next_region = get_dominating_region(phase, load_use_control, ctrl);
-      while (phase->idom(next_region) != catch_node) {
-        next_region = phase->idom(next_region);
-        if (trace) tty->print_cr("Moving up idom to region ctrl %i", next_region->_idx);
-      }
-      assert(phase->is_dominator(catch_node, next_region), "Sanity");
-
-      // Create or reuse phi node that collect all cloned loads and feed it to the use.
-      Node* test_phi = phi_map[next_region->_idx];
-      if ((test_phi != NULL) && test_phi->is_Phi()) {
-        // Reuse an already created phi
-        if (trace) tty->print_cr("    Using cached Phi %i on load_use %i", test_phi->_idx, load_use->_idx);
-        phase->igvn().rehash_node_delayed(load_use);
-        load_use->replace_edge(load, test_phi);
-        // Now this use is done
-      } else {
-        // Otherwise we need to create one or more phis
-        PhiNode* next_phi = new PhiNode(next_region, load->type());
-        phi_map[next_region->_idx] = next_phi; // cache new phi
-        phase->igvn().rehash_node_delayed(load_use);
-        load_use->replace_edge(load, next_phi);
-
-        int dominators_of_region = 0;
-        do {
-          // New phi, connect to region and add all loads as in.
-          Node* region = next_region;
-          assert(region->isa_Region() && region->req() > 2, "Catch dead region nodes");
-          PhiNode* new_phi = next_phi;
-
-          if (trace) tty->print_cr("Created Phi %i on load %i with control %i", new_phi->_idx, load->_idx, region->_idx);
-
-          // Need to add all cloned loads to the phi, taking care that the right path is matched
-          dominators_of_region = 0; // reset for new region
-          for (unsigned int reg_i = 1; reg_i < region->req(); reg_i++) {
-            Node* region_pred = region->in(reg_i);
-            assert(region_pred->is_CFG(), "check");
-            bool pred_has_dominator = false;
-            for (int c = 0; c < number_of_catch_projs; c++) {
-              Node* catchproj = catch_node->raw_out(c);
-              if (phase->is_dominator(catchproj, region_pred)) {
-                new_phi->set_req(reg_i, proj_to_load_mapping[c]);
-                if (trace) tty->print_cr(" - Phi in(%i) set to load %i", reg_i, proj_to_load_mapping[c]->_idx);
-                pred_has_dominator = true;
-                dominators_of_region++;
-                break;
-              }
-            }
-
-            // Sometimes we need to chain several phis.
-            if (!pred_has_dominator) {
-              assert(dominators_of_region <= 1, "More than one region can't require extra phi");
-              if (trace) tty->print_cr(" - Region %i pred %i not dominated by catch proj", region->_idx, region_pred->_idx);
-              // Continue search on on this region_pred
-              // - walk up to next region
-              // - create a new phi and connect to first new_phi
-              next_region = get_dominating_region(phase, region_pred, ctrl);
-
-              // Lookup if there already is a phi, create a new otherwise
-              Node* test_phi = phi_map[next_region->_idx];
-              if ((test_phi != NULL) && test_phi->is_Phi()) {
-                next_phi = test_phi->isa_Phi();
-                dominators_of_region++; // record that a match was found and that we are done
-                if (trace) tty->print_cr("    Using cached phi Phi %i on control %i", next_phi->_idx, next_region->_idx);
-              } else {
-                next_phi = new PhiNode(next_region, load->type());
-                phi_map[next_region->_idx] = next_phi;
-              }
-              new_phi->set_req(reg_i, next_phi);
-            }
-          }
-
-          new_phi->set_req(0, region);
-          phase->igvn().register_new_node_with_optimizer(new_phi);
-          phase->set_ctrl(new_phi, region);
-
-          assert(dominators_of_region != 0, "Must have found one this iteration");
-        } while (dominators_of_region == 1);
-      }
-      --i;
     }
-  } // end of loop over uses
-
-  assert(load->outcnt() == 0, "All uses should be handled");
-  phase->igvn().remove_dead_node(load);
-  phase->C->print_method(PHASE_CALL_CATCH_CLEANUP, 4, load->_idx);
-
-  // Now we should be home
-  phase->igvn().set_delay_transform(false);
-}
-
-// Sort out the loads that are between a call ant its catch blocks
-static void process_catch_cleanup_candidate(PhaseIdealLoop* phase, LoadNode* load) {
-  bool trace = phase->C->directive()->ZTraceLoadBarriersOption;
-
-  Node* ctrl = phase->get_ctrl(load);
-  if (!ctrl->is_Proj() || (ctrl->in(0) == NULL) || !ctrl->in(0)->isa_Call()) {
-    return;
   }
-
-  Node* catch_node = ctrl->isa_Proj()->raw_out(0);
-  if (catch_node->is_Catch()) {
-    if (catch_node->outcnt() > 1) {
-      call_catch_cleanup_one(phase, load, ctrl);
-    } else {
-      if (trace) tty->print_cr("Call catch cleanup with only one catch: load %i ", load->_idx);
-    }
-  }
-}
-
-void ZBarrierSetC2::barrier_insertion_phase(Compile* C, PhaseIterGVN& igvn) const {
-  PhaseIdealLoop::optimize(igvn, LoopOptsZBarrierInsertion);
-  if (C->failing())  return;
 }
 
-bool ZBarrierSetC2::optimize_loops(PhaseIdealLoop* phase, LoopOptsMode mode, VectorSet& visited, Node_Stack& nstack, Node_List& worklist) const {
-
-  if (mode == LoopOptsZBarrierInsertion) {
-    // First make sure all loads between call and catch are moved to the catch block
-    clean_catch_blocks(phase);
-
-    // Then expand barriers on all loads
-    insert_load_barriers(phase);
-
-    // Handle all Unsafe that need barriers.
-    insert_barriers_on_unsafe(phase);
-
-    phase->C->clear_major_progress();
-    return true;
-  } else {
-    return false;
-  }
-}
-
-static bool can_simplify_cas(LoadStoreNode* node) {
-  if (node->isa_LoadStoreConditional()) {
-    Node *expected_in = node->as_LoadStoreConditional()->in(LoadStoreConditionalNode::ExpectedIn);
-    return (expected_in->get_ptr_type() == TypePtr::NULL_PTR);
-  } else {
-    return false;
-  }
-}
-
-static void insert_barrier_before_unsafe(PhaseIdealLoop* phase, LoadStoreNode* old_node) {
-
-  Compile *C = phase->C;
-  PhaseIterGVN &igvn = phase->igvn();
-  LoadStoreNode* zclone = NULL;
-  bool is_weak = false;
-
-  Node *in_ctrl = old_node->in(MemNode::Control);
-  Node *in_mem  = old_node->in(MemNode::Memory);
-  Node *in_adr  = old_node->in(MemNode::Address);
-  Node *in_val  = old_node->in(MemNode::ValueIn);
-  const TypePtr *adr_type = old_node->adr_type();
-  const TypePtr* load_type = TypeOopPtr::BOTTOM; // The type for the load we are adding
-
-  switch (old_node->Opcode()) {
-    case Op_CompareAndExchangeP: {
-      zclone = new ZCompareAndExchangePNode(in_ctrl, in_mem, in_adr, in_val, old_node->in(LoadStoreConditionalNode::ExpectedIn),
-              adr_type, old_node->get_ptr_type(), ((CompareAndExchangeNode*)old_node)->order());
-      load_type = old_node->bottom_type()->is_ptr();
-      break;
-    }
-    case Op_WeakCompareAndSwapP: {
-      if (can_simplify_cas(old_node)) {
-        break;
-      }
-      is_weak  = true;
-      zclone = new ZWeakCompareAndSwapPNode(in_ctrl, in_mem, in_adr, in_val, old_node->in(LoadStoreConditionalNode::ExpectedIn),
-              ((CompareAndSwapNode*)old_node)->order());
-      adr_type = TypePtr::BOTTOM;
-      break;
-    }
-    case Op_CompareAndSwapP: {
-      if (can_simplify_cas(old_node)) {
-        break;
-      }
-      zclone = new ZCompareAndSwapPNode(in_ctrl, in_mem, in_adr, in_val, old_node->in(LoadStoreConditionalNode::ExpectedIn),
-              ((CompareAndSwapNode*)old_node)->order());
-      adr_type = TypePtr::BOTTOM;
-      break;
-    }
-    case Op_GetAndSetP: {
-      zclone = new ZGetAndSetPNode(in_ctrl, in_mem, in_adr, in_val, old_node->adr_type(), old_node->get_ptr_type());
-      load_type = old_node->bottom_type()->is_ptr();
-      break;
-    }
-  }
-  if (zclone != NULL) {
-    igvn.register_new_node_with_optimizer(zclone, old_node);
-
-    // Make load
-    LoadPNode *load = new LoadPNode(NULL, in_mem, in_adr, adr_type, load_type, MemNode::unordered,
-                                    LoadNode::DependsOnlyOnTest);
-    load_set_expanded_barrier(load);
-    igvn.register_new_node_with_optimizer(load);
-    igvn.replace_node(old_node, zclone);
-
-    Node *barrier = new LoadBarrierNode(C, NULL, in_mem, load, in_adr, is_weak);
-    Node *barrier_val = new ProjNode(barrier, LoadBarrierNode::Oop);
-    Node *barrier_ctrl = new ProjNode(barrier, LoadBarrierNode::Control);
-
-    igvn.register_new_node_with_optimizer(barrier);
-    igvn.register_new_node_with_optimizer(barrier_val);
-    igvn.register_new_node_with_optimizer(barrier_ctrl);
-
-    // loop over all of in_ctrl usages and move to barrier_ctrl
-    for (DUIterator_Last imin, i = in_ctrl->last_outs(imin); i >= imin; --i) {
-      Node *use = in_ctrl->last_out(i);
-      uint l;
-      for (l = 0; use->in(l) != in_ctrl; l++) {}
-      igvn.replace_input_of(use, l, barrier_ctrl);
-    }
-
-    load->set_req(MemNode::Control, in_ctrl);
-    barrier->set_req(LoadBarrierNode::Control, in_ctrl);
-    zclone->add_req(barrier_val); // add req as keep alive.
-
-    C->print_method(PHASE_ADD_UNSAFE_BARRIER, 4, zclone->_idx);
-  }
-}
-
-void ZBarrierSetC2::insert_barriers_on_unsafe(PhaseIdealLoop* phase) const {
-  Compile *C = phase->C;
-  PhaseIterGVN &igvn = phase->igvn();
-  uint new_ids = C->unique();
-  VectorSet visited(Thread::current()->resource_area());
-  GrowableArray<Node *> nodeStack(Thread::current()->resource_area(), 0, 0, NULL);
-  nodeStack.push(C->root());
-  visited.test_set(C->root()->_idx);
-
-  // Traverse all nodes, visit all unsafe ops that require a barrier
-  while (nodeStack.length() > 0) {
-    Node *n = nodeStack.pop();
-
-    bool is_old_node = (n->_idx < new_ids); // don't process nodes that were created during cleanup
-    if (is_old_node) {
-      if (n->is_LoadStore()) {
-        LoadStoreNode* lsn = n->as_LoadStore();
-        if (lsn->has_barrier()) {
-          BasicType bt = lsn->in(MemNode::Address)->bottom_type()->basic_type();
-          assert ((bt == T_OBJECT || bt == T_ARRAY), "Sanity test");
-          insert_barrier_before_unsafe(phase, lsn);
-        }
-      }
-    }
-    for (uint i = 0; i < n->len(); i++) {
-      if (n->in(i)) {
-        if (!visited.test_set(n->in(i)->_idx)) {
-          nodeStack.push(n->in(i));
-        }
-      }
-    }
-  }
-
-  igvn.optimize();
-  C->print_method(PHASE_ADD_UNSAFE_BARRIER, 2);
-}
-
-// The purpose of ZBarrierSetC2::clean_catch_blocks is to prepare the IR for
-// splicing in load barrier nodes.
-//
-// The problem is that we might have instructions between a call and its catch nodes.
-// (This is usually handled in PhaseCFG:call_catch_cleanup, which clones mach nodes in
-// already scheduled blocks.) We can't have loads that require barriers there,
-// because we need to splice in new control flow, and that would violate the IR.
-//
-// clean_catch_blocks find all Loads that require a barrier and clone them and any
-// dependent instructions to each use. The loads must be in the beginning of the catch block
-// before any store.
-//
-// Sometimes the loads use will be at a place dominated by all catch blocks, then we need
-// a load in each catch block, and a Phi at the dominated use.
-
-void ZBarrierSetC2::clean_catch_blocks(PhaseIdealLoop* phase) const {
-
-  Compile *C = phase->C;
-  uint new_ids = C->unique();
-  PhaseIterGVN &igvn = phase->igvn();
-  VectorSet visited(Thread::current()->resource_area());
-  GrowableArray<Node *> nodeStack(Thread::current()->resource_area(), 0, 0, NULL);
-  nodeStack.push(C->root());
-  visited.test_set(C->root()->_idx);
-
-  // Traverse all nodes, visit all loads that require a barrier
-  while(nodeStack.length() > 0) {
-    Node *n = nodeStack.pop();
-
-    for (uint i = 0; i < n->len(); i++) {
-      if (n->in(i)) {
-        if (!visited.test_set(n->in(i)->_idx)) {
-          nodeStack.push(n->in(i));
-        }
-      }
-    }
-
-    bool is_old_node = (n->_idx < new_ids); // don't process nodes that were created during cleanup
-    if (n->is_Load() && is_old_node) {
-      LoadNode* load = n->isa_Load();
-      // only care about loads that will have a barrier
-      if (load_require_barrier(load)) {
-        process_catch_cleanup_candidate(phase, load);
-      }
-    }
-  }
-
-  C->print_method(PHASE_CALL_CATCH_CLEANUP, 2);
-}
-
-class DomDepthCompareClosure : public CompareClosure<LoadNode*> {
-  PhaseIdealLoop* _phase;
-
-public:
-  DomDepthCompareClosure(PhaseIdealLoop* phase) : _phase(phase) { }
-
-  int do_compare(LoadNode* const &n1, LoadNode* const &n2) {
-    int d1 = _phase->dom_depth(_phase->get_ctrl(n1));
-    int d2 = _phase->dom_depth(_phase->get_ctrl(n2));
-    if (d1 == d2) {
-      // Compare index if the depth is the same, ensures all entries are unique.
-      return n1->_idx - n2->_idx;
-    } else {
-      return d2 - d1;
-    }
-  }
-};
-
-// Traverse graph and add all loadPs to list, sorted by dom depth
-void gather_loadnodes_sorted(PhaseIdealLoop* phase, GrowableArray<LoadNode*>* loadList) {
-
-  VectorSet visited(Thread::current()->resource_area());
-  GrowableArray<Node *> nodeStack(Thread::current()->resource_area(), 0, 0, NULL);
-  DomDepthCompareClosure ddcc(phase);
-
-  nodeStack.push(phase->C->root());
-  while(nodeStack.length() > 0) {
-    Node *n = nodeStack.pop();
-    if (visited.test(n->_idx)) {
-      continue;
-    }
-
-    if (n->isa_Load()) {
-      LoadNode *load = n->as_Load();
-      if (load_require_barrier(load)) {
-        assert(phase->get_ctrl(load) != NULL, "sanity");
-        assert(phase->dom_depth(phase->get_ctrl(load)) != 0, "sanity");
-        loadList->insert_sorted(&ddcc, load);
-      }
-    }
-
-    visited.set(n->_idx);
-    for (uint i = 0; i < n->req(); i++) {
-      if (n->in(i)) {
-        if (!visited.test(n->in(i)->_idx)) {
-          nodeStack.push(n->in(i));
-        }
-      }
-    }
-  }
-}
-
-// Add LoadBarriers to all LoadPs
-void ZBarrierSetC2::insert_load_barriers(PhaseIdealLoop* phase) const {
-
-  bool trace = phase->C->directive()->ZTraceLoadBarriersOption;
-  GrowableArray<LoadNode *> loadList(Thread::current()->resource_area(), 0, 0, NULL);
-  gather_loadnodes_sorted(phase, &loadList);
-
-  PhaseIterGVN &igvn = phase->igvn();
-  int count = 0;
-
-  for (GrowableArrayIterator<LoadNode *> loadIter = loadList.begin(); loadIter != loadList.end(); ++loadIter) {
-    LoadNode *load = *loadIter;
+#endif
 
-    if (load_has_expanded_barrier(load)) {
-      continue;
-    }
+bool ZBarrierSetC2::escape_add_to_con_graph(ConnectionGraph* conn_graph, PhaseGVN* gvn, Unique_Node_List* delayed_worklist, Node* n, uint opcode) const {
+  switch (opcode) {
+    case Op_LoadBarrierSlowReg:
+    case Op_LoadBarrierWeakSlowReg:
+      conn_graph->add_objload_to_connection_graph(n, delayed_worklist);
+      return true;
 
-    do {
-      // Insert a barrier on a loadP
-      // if another load is found that needs to be expanded first, retry on that one
-      LoadNode* result = insert_one_loadbarrier(phase, load, phase->get_ctrl(load));
-      while (result != NULL) {
-        result = insert_one_loadbarrier(phase, result, phase->get_ctrl(result));
+    case Op_Proj:
+      if (n->as_Proj()->_con != LoadBarrierNode::Oop || !n->in(0)->is_LoadBarrier()) {
+        return false;
       }
-    } while (!load_has_expanded_barrier(load));
+      conn_graph->add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(0)->in(LoadBarrierNode::Oop), delayed_worklist);
+      return true;
   }
 
-  phase->C->print_method(PHASE_INSERT_BARRIER, 2);
-}
-
-void push_antidependent_stores(PhaseIdealLoop* phase, Node_Stack& nodestack, LoadNode* start_load) {
-  // push all stores on the same mem, that can_alias
-  // Any load found must be handled first
-  PhaseIterGVN &igvn = phase->igvn();
-  int load_alias_idx = igvn.C->get_alias_index(start_load->adr_type());
-
-  Node *mem = start_load->in(1);
-  for (DUIterator_Fast imax, u = mem->fast_outs(imax); u < imax; u++) {
-    Node *mem_use = mem->fast_out(u);
-
-    if (mem_use == start_load) continue;
-    if (!mem_use->is_Store()) continue;
-    if (!phase->has_ctrl(mem_use)) continue;
-    if (phase->get_ctrl(mem_use) != phase->get_ctrl(start_load)) continue;
-
-    // add any aliasing store in this block
-    StoreNode *store = mem_use->isa_Store();
-    const TypePtr *adr_type = store->adr_type();
-    if (igvn.C->can_alias(adr_type, load_alias_idx)) {
-      nodestack.push(store, 0);
-    }
-  }
+  return false;
 }
 
-LoadNode* ZBarrierSetC2::insert_one_loadbarrier(PhaseIdealLoop* phase, LoadNode* start_load, Node* ctrl) const {
-  bool trace = phase->C->directive()->ZTraceLoadBarriersOption;
-  PhaseIterGVN &igvn = phase->igvn();
-
-  // Check for other loadPs at the same loop depth that is reachable by a DFS
-  // - if found - return it. It needs to be inserted first
-  // - otherwise proceed and insert barrier
-
-  VectorSet visited(Thread::current()->resource_area());
-  Node_Stack nodestack(100);
-
-  nodestack.push(start_load, 0);
-  push_antidependent_stores(phase, nodestack, start_load);
-
-  while(!nodestack.is_empty()) {
-    Node* n = nodestack.node(); // peek
-    nodestack.pop();
-    if (visited.test(n->_idx)) {
-      continue;
-    }
-
-    if (n->is_Load() && n != start_load && load_require_barrier(n->as_Load()) && !load_has_expanded_barrier(n->as_Load())) {
-      // Found another load that needs a barrier in the same block. Must expand later loads first.
-      if (trace) tty->print_cr(" * Found LoadP %i on DFS", n->_idx);
-      return n->as_Load(); // return node that should be expanded first
-    }
-
-    if (!phase->has_ctrl(n)) continue;
-    if (phase->get_ctrl(n) != phase->get_ctrl(start_load)) continue;
-    if (n->is_Phi()) continue;
-
-    visited.set(n->_idx);
-    // push all children
-    for (DUIterator_Fast imax, ii = n->fast_outs(imax); ii < imax; ii++) {
-      Node* c = n->fast_out(ii);
-      if (c != NULL) {
-        nodestack.push(c, 0);
+bool ZBarrierSetC2::escape_add_final_edges(ConnectionGraph* conn_graph, PhaseGVN* gvn, Node* n, uint opcode) const {
+  switch (opcode) {
+    case Op_LoadBarrierSlowReg:
+    case Op_LoadBarrierWeakSlowReg:
+      if (gvn->type(n)->make_ptr() == NULL) {
+        return false;
       }
-    }
-  }
-
-  insert_one_loadbarrier_inner(phase, start_load, ctrl, visited);
-  return NULL;
-}
-
-void ZBarrierSetC2::insert_one_loadbarrier_inner(PhaseIdealLoop* phase, LoadNode* load, Node* ctrl, VectorSet visited2) const {
-  PhaseIterGVN &igvn = phase->igvn();
-  Compile* C = igvn.C;
-  bool trace = C->directive()->ZTraceLoadBarriersOption;
-
-  // create barrier
-  Node* barrier = new LoadBarrierNode(C, NULL, load->in(LoadNode::Memory), NULL, load->in(LoadNode::Address), load_has_weak_barrier(load));
-  Node* barrier_val = new ProjNode(barrier, LoadBarrierNode::Oop);
-  Node* barrier_ctrl = new ProjNode(barrier, LoadBarrierNode::Control);
-
-  if (trace) tty->print_cr("Insert load %i with barrier: %i and ctrl : %i", load->_idx, barrier->_idx, ctrl->_idx);
-
-  // Splice control
-  // - insert barrier control diamond between loads ctrl and ctrl successor on path to block end.
-  // - If control successor is a catch, step over to next.
-  Node* ctrl_succ = NULL;
-  for (DUIterator_Fast imax, j = ctrl->fast_outs(imax); j < imax; j++) {
-    Node* tmp = ctrl->fast_out(j);
-
-    // - CFG nodes is the ones we are going to splice (1 only!)
-    // - Phi nodes will continue to hang from the region node!
-    // - self loops should be skipped
-    if (tmp->is_Phi() || tmp == ctrl) {
-      continue;
-    }
-
-    if (tmp->is_CFG()) {
-      assert(ctrl_succ == NULL, "There can be only one");
-      ctrl_succ = tmp;
-      continue;
-    }
-  }
-
-  // Now splice control
-  assert(ctrl_succ != load, "sanity");
-  assert(ctrl_succ != NULL, "Broken IR");
-  bool found = false;
-  for(uint k = 0; k < ctrl_succ->req(); k++) {
-    if (ctrl_succ->in(k) == ctrl) {
-      assert(!found, "sanity");
-      if (trace) tty->print_cr(" Move CFG ctrl_succ %i to barrier_ctrl", ctrl_succ->_idx);
-      igvn.replace_input_of(ctrl_succ, k, barrier_ctrl);
-      found = true;
-      k--;
-    }
-  }
-
-  // For all successors of ctrl - move all visited to become successors of barrier_ctrl instead
-  for (DUIterator_Fast imax, r = ctrl->fast_outs(imax); r < imax; r++) {
-    Node* tmp = ctrl->fast_out(r);
-    if (visited2.test(tmp->_idx) && (tmp != load)) {
-      if (trace) tty->print_cr(" Move ctrl_succ %i to barrier_ctrl", tmp->_idx);
-      igvn.replace_input_of(tmp, 0, barrier_ctrl);
-      --r; --imax;
-    }
-  }
-
-  // Move the loads user to the barrier
-  for (DUIterator_Fast imax, i = load->fast_outs(imax); i < imax; i++) {
-    Node* u = load->fast_out(i);
-    if (u->isa_LoadBarrier()) {
-      continue;
-    }
+      conn_graph->add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(MemNode::Address), NULL);
+      return true;
 
-    // find correct input  - replace with iterator?
-    for(uint j = 0; j < u->req(); j++) {
-      if (u->in(j) == load) {
-        igvn.replace_input_of(u, j, barrier_val);
-        --i; --imax; // Adjust the iterator of the *outer* loop
-        break; // some nodes (calls) might have several uses from the same node
+    case Op_Proj:
+      if (n->as_Proj()->_con != LoadBarrierNode::Oop || !n->in(0)->is_LoadBarrier()) {
+        return false;
       }
-    }
+      conn_graph->add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(0)->in(LoadBarrierNode::Oop), NULL);
+      return true;
   }
 
-  // Connect barrier to load and control
-  barrier->set_req(LoadBarrierNode::Oop, load);
-  barrier->set_req(LoadBarrierNode::Control, ctrl);
-
-  igvn.rehash_node_delayed(load);
-  igvn.register_new_node_with_optimizer(barrier);
-  igvn.register_new_node_with_optimizer(barrier_val);
-  igvn.register_new_node_with_optimizer(barrier_ctrl);
-  load_set_expanded_barrier(load);
-
-  C->print_method(PHASE_INSERT_BARRIER, 3, load->_idx);
-}
-
-// The bad_mask in the ThreadLocalData shouldn't have an anti-dep-check.
-// The bad_mask address if of type TypeRawPtr, but that will alias
-// InitializeNodes until the type system is expanded.
-bool ZBarrierSetC2::needs_anti_dependence_check(const Node* node) const {
-  MachNode* mnode = node->as_Mach();
-  if (mnode != NULL) {
-    intptr_t offset = 0;
-    const TypePtr *adr_type2 = NULL;
-    const Node* base = mnode->get_base_and_disp(offset, adr_type2);
-    if ((base != NULL) &&
-        (base->is_Mach() && base->as_Mach()->ideal_Opcode() == Op_ThreadLocal) &&
-        (offset == in_bytes(ZThreadLocalData::address_bad_mask_offset()))) {
-      return false;
-    }
-  }
-  return true;
+  return false;
 }
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