6895383: JCK test throws NPE for method compiled with Escape Analysis

Summary: Add missing checks for MemBar nodes in EA.
Reviewed-by: never

src/share/vm/opto/compile.cpp

@@ -1852,6 +1852,7 @@ void Compile::dump_asm(int *pcs, uint pc_limit) {
           !n->is_Phi() &&       // a few noisely useless nodes
           !n->is_Proj() &&
           !n->is_MachTemp() &&
+          !n->is_SafePointScalarObject() &&
           !n->is_Catch() &&     // Would be nice to print exception table targets
           !n->is_MergeMem() &&  // Not very interesting
           !n->is_top() &&       // Debug info table constants

src/share/vm/opto/escape.cpp

@@ -779,6 +779,13 @@ Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArra
       } else {
         break;
       }
+    } else if (result->is_ClearArray()) {
+      if (!ClearArrayNode::step_through(&result, (uint)tinst->instance_id(), phase)) {
+        // Can not bypass initialization of the instance
+        // we are looking for.
+        break;
+      }
+      // Otherwise skip it (the call updated 'result' value).
     } else if (result->Opcode() == Op_SCMemProj) {
       assert(result->in(0)->is_LoadStore(), "sanity");
       const Type *at = phase->type(result->in(0)->in(MemNode::Address));
@@ -808,7 +815,6 @@ Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArra
   return result;
 }
 
-
 //
 //  Convert the types of unescaped object to instance types where possible,
 //  propagate the new type information through the graph, and update memory
@@ -900,7 +906,6 @@ Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArra
 //
 void ConnectionGraph::split_unique_types(GrowableArray<Node *>  &alloc_worklist) {
   GrowableArray<Node *>  memnode_worklist;
-  GrowableArray<Node *>  mergemem_worklist;
   GrowableArray<PhiNode *>  orig_phis;
   PhaseGVN  *igvn = _compile->initial_gvn();
   uint new_index_start = (uint) _compile->num_alias_types();
@@ -1025,7 +1030,7 @@ void ConnectionGraph::split_unique_types(GrowableArray<Node *>  &alloc_worklist)
               alloc_worklist.append_if_missing(addp2);
             }
             alloc_worklist.append_if_missing(use);
-          } else if (use->is_Initialize()) {
+          } else if (use->is_MemBar()) {
             memnode_worklist.append_if_missing(use);
           }
         }
@@ -1035,10 +1040,12 @@ void ConnectionGraph::split_unique_types(GrowableArray<Node *>  &alloc_worklist)
       PointsTo(ptset, get_addp_base(n), igvn);
       assert(ptset.Size() == 1, "AddP address is unique");
       uint elem = ptset.getelem(); // Allocation node's index
-      if (elem == _phantom_object)
+      if (elem == _phantom_object) {
+        assert(false, "escaped allocation");
         continue; // Assume the value was set outside this method.
+      }
       Node *base = get_map(elem);  // CheckCastPP node
-      if (!split_AddP(n, base, igvn)) continue; // wrong type
+      if (!split_AddP(n, base, igvn)) continue; // wrong type from dead path
       tinst = igvn->type(base)->isa_oopptr();
     } else if (n->is_Phi() ||
                n->is_CheckCastPP() ||
@@ -1053,8 +1060,10 @@ void ConnectionGraph::split_unique_types(GrowableArray<Node *>  &alloc_worklist)
       PointsTo(ptset, n, igvn);
       if (ptset.Size() == 1) {
         uint elem = ptset.getelem(); // Allocation node's index
-        if (elem == _phantom_object)
+        if (elem == _phantom_object) {
+          assert(false, "escaped allocation");
           continue; // Assume the value was set outside this method.
+        }
         Node *val = get_map(elem);   // CheckCastPP node
         TypeNode *tn = n->as_Type();
         tinst = igvn->type(val)->isa_oopptr();
@@ -1069,8 +1078,7 @@ void ConnectionGraph::split_unique_types(GrowableArray<Node *>  &alloc_worklist)
           tn_t = tn_type->isa_oopptr();
         }
 
-        if (tn_t != NULL &&
-            tinst->cast_to_instance_id(TypeOopPtr::InstanceBot)->higher_equal(tn_t)) {
+        if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) {
           if (tn_type->isa_narrowoop()) {
             tn_type = tinst->make_narrowoop();
           } else {
@@ -1082,33 +1090,25 @@ void ConnectionGraph::split_unique_types(GrowableArray<Node *>  &alloc_worklist)
           igvn->hash_insert(tn);
           record_for_optimizer(n);
         } else {
-          continue; // wrong type
+          assert(tn_type == TypePtr::NULL_PTR ||
+                 tn_t != NULL && !tinst->klass()->is_subtype_of(tn_t->klass()),
+                 "unexpected type");
+          continue; // Skip dead path with different type
         }
       }
     } else {
+      debug_only(n->dump();)
+      assert(false, "EA: unexpected node");
       continue;
     }
-    // push users on appropriate worklist
+    // push allocation's users on appropriate worklist
     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
       Node *use = n->fast_out(i);
       if(use->is_Mem() && use->in(MemNode::Address) == n) {
+        // Load/store to instance's field
         memnode_worklist.append_if_missing(use);
-      } else if (use->is_Initialize()) {
+      } else if (use->is_MemBar()) {
         memnode_worklist.append_if_missing(use);
-      } else if (use->is_MergeMem()) {
-        mergemem_worklist.append_if_missing(use);
-      } else if (use->is_SafePoint() && tinst != NULL) {
-        // Look for MergeMem nodes for calls which reference unique allocation
-        // (through CheckCastPP nodes) even for debug info.
-        Node* m = use->in(TypeFunc::Memory);
-        uint iid = tinst->instance_id();
-        while (m->is_Proj() && m->in(0)->is_SafePoint() &&
-               m->in(0) != use && !m->in(0)->_idx != iid) {
-          m = m->in(0)->in(TypeFunc::Memory);
-        }
-        if (m->is_MergeMem()) {
-          mergemem_worklist.append_if_missing(m);
-        }
       } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
         Node* addp2 = find_second_addp(use, n);
         if (addp2 != NULL) {
@@ -1121,6 +1121,29 @@ void ConnectionGraph::split_unique_types(GrowableArray<Node *>  &alloc_worklist)
                  use->is_DecodeN() ||
                  (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
         alloc_worklist.append_if_missing(use);
+#ifdef ASSERT
+      } else if (use->is_Mem()) {
+        assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
+      } else if (use->is_MergeMem()) {
+        assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
+      } else if (use->is_SafePoint()) {
+        // Look for MergeMem nodes for calls which reference unique allocation
+        // (through CheckCastPP nodes) even for debug info.
+        Node* m = use->in(TypeFunc::Memory);
+        if (m->is_MergeMem()) {
+          assert(_mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
+        }
+      } else {
+        uint op = use->Opcode();
+        if (!(op == Op_CmpP || op == Op_Conv2B ||
+              op == Op_CastP2X || op == Op_StoreCM ||
+              op == Op_FastLock || op == Op_AryEq || op == Op_StrComp ||
+              op == Op_StrEquals || op == Op_StrIndexOf)) {
+          n->dump();
+          use->dump();
+          assert(false, "EA: missing allocation reference path");
+        }
+#endif
       }
     }
 
@@ -1138,13 +1161,11 @@ void ConnectionGraph::split_unique_types(GrowableArray<Node *>  &alloc_worklist)
     Node *n = memnode_worklist.pop();
     if (visited.test_set(n->_idx))
       continue;
-    if (n->is_Phi()) {
-      assert(n->as_Phi()->adr_type() != TypePtr::BOTTOM, "narrow memory slice required");
-      // we don't need to do anything, but the users must be pushed if we haven't processed
-      // this Phi before
-    } else if (n->is_Initialize()) {
-      // we don't need to do anything, but the users of the memory projection must be pushed
-      n = n->as_Initialize()->proj_out(TypeFunc::Memory);
+    if (n->is_Phi() || n->is_ClearArray()) {
+      // we don't need to do anything, but the users must be pushed
+    } else if (n->is_MemBar()) { // Initialize, MemBar nodes
+      // we don't need to do anything, but the users must be pushed
+      n = n->as_MemBar()->proj_out(TypeFunc::Memory);
       if (n == NULL)
         continue;
     } else {
@@ -1181,31 +1202,48 @@ void ConnectionGraph::split_unique_types(GrowableArray<Node *>  &alloc_worklist)
     // push user on appropriate worklist
     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
       Node *use = n->fast_out(i);
-      if (use->is_Phi()) {
+      if (use->is_Phi() || use->is_ClearArray()) {
         memnode_worklist.append_if_missing(use);
       } else if(use->is_Mem() && use->in(MemNode::Memory) == n) {
+        if (use->Opcode() == Op_StoreCM) // Ignore cardmark stores
+          continue;
         memnode_worklist.append_if_missing(use);
-      } else if (use->is_Initialize()) {
+      } else if (use->is_MemBar()) {
         memnode_worklist.append_if_missing(use);
+#ifdef ASSERT
+      } else if(use->is_Mem()) {
+        assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
       } else if (use->is_MergeMem()) {
-        mergemem_worklist.append_if_missing(use);
+        assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
+      } else {
+        uint op = use->Opcode();
+        if (!(op == Op_StoreCM ||
+              (op == Op_CallLeaf && use->as_CallLeaf()->_name != NULL &&
+               strcmp(use->as_CallLeaf()->_name, "g1_wb_pre") == 0) ||
+              op == Op_AryEq || op == Op_StrComp ||
+              op == Op_StrEquals || op == Op_StrIndexOf)) {
+          n->dump();
+          use->dump();
+          assert(false, "EA: missing memory path");
+        }
+#endif
       }
     }
   }
 
   //  Phase 3:  Process MergeMem nodes from mergemem_worklist.
-  //            Walk each memory moving the first node encountered of each
+  //            Walk each memory slice moving the first node encountered of each
   //            instance type to the the input corresponding to its alias index.
-  while (mergemem_worklist.length() != 0) {
-    Node *n = mergemem_worklist.pop();
-    assert(n->is_MergeMem(), "MergeMem node required.");
-    if (visited.test_set(n->_idx))
-      continue;
-    MergeMemNode *nmm = n->as_MergeMem();
+  uint length = _mergemem_worklist.length();
+  for( uint next = 0; next < length; ++next ) {
+    MergeMemNode* nmm = _mergemem_worklist.at(next);
+    assert(!visited.test_set(nmm->_idx), "should not be visited before");
     // Note: we don't want to use MergeMemStream here because we only want to
     // scan inputs which exist at the start, not ones we add during processing.
-    uint nslices = nmm->req();
+    // Note 2: MergeMem may already contains instance memory slices added
+    // during find_inst_mem() call when memory nodes were processed above.
     igvn->hash_delete(nmm);
+    uint nslices = nmm->req();
     for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
       Node* mem = nmm->in(i);
       Node* cur = NULL;
@@ -1259,41 +1297,6 @@ void ConnectionGraph::split_unique_types(GrowableArray<Node *>  &alloc_worklist)
     }
     igvn->hash_insert(nmm);
     record_for_optimizer(nmm);
-
-    // Propagate new memory slices to following MergeMem nodes.
-    for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
-      Node *use = n->fast_out(i);
-      if (use->is_Call()) {
-        CallNode* in = use->as_Call();
-        if (in->proj_out(TypeFunc::Memory) != NULL) {
-          Node* m = in->proj_out(TypeFunc::Memory);
-          for (DUIterator_Fast jmax, j = m->fast_outs(jmax); j < jmax; j++) {
-            Node* mm = m->fast_out(j);
-            if (mm->is_MergeMem()) {
-              mergemem_worklist.append_if_missing(mm);
-            }
-          }
-        }
-        if (use->is_Allocate()) {
-          use = use->as_Allocate()->initialization();
-          if (use == NULL) {
-            continue;
-          }
-        }
-      }
-      if (use->is_Initialize()) {
-        InitializeNode* in = use->as_Initialize();
-        if (in->proj_out(TypeFunc::Memory) != NULL) {
-          Node* m = in->proj_out(TypeFunc::Memory);
-          for (DUIterator_Fast jmax, j = m->fast_outs(jmax); j < jmax; j++) {
-            Node* mm = m->fast_out(j);
-            if (mm->is_MergeMem()) {
-              mergemem_worklist.append_if_missing(mm);
-            }
-          }
-        }
-      }
-    }
   }
 
   //  Phase 4:  Update the inputs of non-instance memory Phis and
@@ -1381,8 +1384,20 @@ bool ConnectionGraph::compute_escape() {
         ptnode_adr(n->_idx)->node_type() == PointsToNode::JavaObject) {
       has_allocations = true;
     }
-    if(n->is_AddP())
+    if(n->is_AddP()) {
+      // Collect address nodes which directly reference an allocation.
+      // Use them during stage 3 below to build initial connection graph
+      // field edges. Other field edges could be added after StoreP/LoadP
+      // nodes are processed during stage 4 below.
+      Node* base = get_addp_base(n);
+      if(base->is_Proj() && base->in(0)->is_Allocate()) {
         cg_worklist.append(n->_idx);
+      }
+    } else if (n->is_MergeMem()) {
+      // Collect all MergeMem nodes to add memory slices for
+      // scalar replaceable objects in split_unique_types().
+      _mergemem_worklist.append(n->as_MergeMem());
+    }
     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
       Node* m = n->fast_out(i);   // Get user
       worklist_init.push(m);
@@ -1423,12 +1438,13 @@ bool ConnectionGraph::compute_escape() {
     }
   }
 
-  VectorSet ptset(Thread::current()->resource_area());
+  Arena* arena = Thread::current()->resource_area();
+  VectorSet ptset(arena);
   GrowableArray<uint>  deferred_edges;
-  VectorSet visited(Thread::current()->resource_area());
+  VectorSet visited(arena);
 
-  // 5. Remove deferred edges from the graph and collect
-  //    information needed for type splitting.
+  // 5. Remove deferred edges from the graph and adjust
+  //    escape state of nonescaping objects.
   cg_length = cg_worklist.length();
   for( uint next = 0; next < cg_length; ++next ) {
     int ni = cg_worklist.at(next);
@@ -1438,98 +1454,9 @@ bool ConnectionGraph::compute_escape() {
       remove_deferred(ni, &deferred_edges, &visited);
       Node *n = ptn->_node;
       if (n->is_AddP()) {
-        // Search for objects which are not scalar replaceable.
-        // Mark their escape state as ArgEscape to propagate the state
-        // to referenced objects.
-        // Note: currently there are no difference in compiler optimizations
-        // for ArgEscape objects and NoEscape objects which are not
-        // scalar replaceable.
-
-        int offset = ptn->offset();
-        Node *base = get_addp_base(n);
-        ptset.Clear();
-        PointsTo(ptset, base, igvn);
-        int ptset_size = ptset.Size();
-
-        // Check if a field's initializing value is recorded and add
-        // a corresponding NULL field's value if it is not recorded.
-        // Connection Graph does not record a default initialization by NULL
-        // captured by Initialize node.
-        //
-        // Note: it will disable scalar replacement in some cases:
-        //
-        //    Point p[] = new Point[1];
-        //    p[0] = new Point(); // Will be not scalar replaced
-        //
-        // but it will save us from incorrect optimizations in next cases:
-        //
-        //    Point p[] = new Point[1];
-        //    if ( x ) p[0] = new Point(); // Will be not scalar replaced
-        //
-        // Without a control flow analysis we can't distinguish above cases.
-        //
-        if (offset != Type::OffsetBot && ptset_size == 1) {
-          uint elem = ptset.getelem(); // Allocation node's index
-          // It does not matter if it is not Allocation node since
-          // only non-escaping allocations are scalar replaced.
-          if (ptnode_adr(elem)->_node->is_Allocate() &&
-              ptnode_adr(elem)->escape_state() == PointsToNode::NoEscape) {
-            AllocateNode* alloc = ptnode_adr(elem)->_node->as_Allocate();
-            InitializeNode* ini = alloc->initialization();
-            Node* value = NULL;
-            if (ini != NULL) {
-              BasicType ft = UseCompressedOops ? T_NARROWOOP : T_OBJECT;
-              Node* store = ini->find_captured_store(offset, type2aelembytes(ft), igvn);
-              if (store != NULL && store->is_Store())
-                value = store->in(MemNode::ValueIn);
-            }
-            if (value == NULL || value != ptnode_adr(value->_idx)->_node) {
-              // A field's initializing value was not recorded. Add NULL.
-              uint null_idx = UseCompressedOops ? _noop_null : _oop_null;
-              add_pointsto_edge(ni, null_idx);
-            }
-          }
-        }
-
-        // An object is not scalar replaceable if the field which may point
-        // to it has unknown offset (unknown element of an array of objects).
-        //
-        if (offset == Type::OffsetBot) {
-          uint e_cnt = ptn->edge_count();
-          for (uint ei = 0; ei < e_cnt; ei++) {
-            uint npi = ptn->edge_target(ei);
-            set_escape_state(npi, PointsToNode::ArgEscape);
-            ptnode_adr(npi)->_scalar_replaceable = false;
-          }
-        }
-
-        // Currently an object is not scalar replaceable if a LoadStore node
-        // access its field since the field value is unknown after it.
-        //
-        bool has_LoadStore = false;
-        for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
-          Node *use = n->fast_out(i);
-          if (use->is_LoadStore()) {
-            has_LoadStore = true;
-            break;
-          }
-        }
-        // An object is not scalar replaceable if the address points
-        // to unknown field (unknown element for arrays, offset is OffsetBot).
-        //
-        // Or the address may point to more then one object. This may produce
-        // the false positive result (set scalar_replaceable to false)
-        // since the flow-insensitive escape analysis can't separate
-        // the case when stores overwrite the field's value from the case
-        // when stores happened on different control branches.
-        //
-        if (ptset_size > 1 || ptset_size != 0 &&
-            (has_LoadStore || offset == Type::OffsetBot)) {
-          for( VectorSetI j(&ptset); j.test(); ++j ) {
-            set_escape_state(j.elem, PointsToNode::ArgEscape);
-            ptnode_adr(j.elem)->_scalar_replaceable = false;
-          }
-        }
+        // Search for objects which are not scalar replaceable
+        // and adjust their escape state.
+        verify_escape_state(ni, ptset, igvn);
       }
     }
   }
@@ -1646,6 +1573,150 @@ bool ConnectionGraph::compute_escape() {
   return has_non_escaping_obj;
 }
 
+// Search for objects which are not scalar replaceable.
+void ConnectionGraph::verify_escape_state(int nidx, VectorSet& ptset, PhaseTransform* phase) {
+  PointsToNode* ptn = ptnode_adr(nidx);
+  Node* n = ptn->_node;
+  assert(n->is_AddP(), "Should be called for AddP nodes only");
+  // Search for objects which are not scalar replaceable.
+  // Mark their escape state as ArgEscape to propagate the state
+  // to referenced objects.
+  // Note: currently there are no difference in compiler optimizations
+  // for ArgEscape objects and NoEscape objects which are not
+  // scalar replaceable.
+
+  Compile* C = _compile;
+
+  int offset = ptn->offset();
+  Node* base = get_addp_base(n);
+  ptset.Clear();
+  PointsTo(ptset, base, phase);
+  int ptset_size = ptset.Size();
+
+  // Check if a oop field's initializing value is recorded and add
+  // a corresponding NULL field's value if it is not recorded.
+  // Connection Graph does not record a default initialization by NULL
+  // captured by Initialize node.
+  //
+  // Note: it will disable scalar replacement in some cases:
+  //
+  //    Point p[] = new Point[1];
+  //    p[0] = new Point(); // Will be not scalar replaced
+  //
+  // but it will save us from incorrect optimizations in next cases:
+  //
+  //    Point p[] = new Point[1];
+  //    if ( x ) p[0] = new Point(); // Will be not scalar replaced
+  //
+  // Do a simple control flow analysis to distinguish above cases.
+  //
+  if (offset != Type::OffsetBot && ptset_size == 1) {
+    uint elem = ptset.getelem(); // Allocation node's index
+    // It does not matter if it is not Allocation node since
+    // only non-escaping allocations are scalar replaced.
+    if (ptnode_adr(elem)->_node->is_Allocate() &&
+        ptnode_adr(elem)->escape_state() == PointsToNode::NoEscape) {
+      AllocateNode* alloc = ptnode_adr(elem)->_node->as_Allocate();
+      InitializeNode* ini = alloc->initialization();
+
+      // Check only oop fields.
+      const Type* adr_type = n->as_AddP()->bottom_type();
+      BasicType basic_field_type = T_INT;
+      if (adr_type->isa_instptr()) {
+        ciField* field = C->alias_type(adr_type->isa_instptr())->field();
+        if (field != NULL) {
+          basic_field_type = field->layout_type();
+        } else {
+          // Ignore non field load (for example, klass load)
+        }
+      } else if (adr_type->isa_aryptr()) {
+        const Type* elemtype = adr_type->isa_aryptr()->elem();
+        basic_field_type = elemtype->array_element_basic_type();
+      } else {
+        // Raw pointers are used for initializing stores so skip it.
+        assert(adr_type->isa_rawptr() && base->is_Proj() &&
+               (base->in(0) == alloc),"unexpected pointer type");
+      }
+      if (basic_field_type == T_OBJECT ||
+          basic_field_type == T_NARROWOOP ||
+          basic_field_type == T_ARRAY) {
+        Node* value = NULL;
+        if (ini != NULL) {
+          BasicType ft = UseCompressedOops ? T_NARROWOOP : T_OBJECT;
+          Node* store = ini->find_captured_store(offset, type2aelembytes(ft), phase);
+          if (store != NULL && store->is_Store()) {
+            value = store->in(MemNode::ValueIn);
+          } else if (ptn->edge_count() > 0) { // Are there oop stores?
+            // Check for a store which follows allocation without branches.
+            // For example, a volatile field store is not collected
+            // by Initialize node. TODO: it would be nice to use idom() here.
+            for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
+              store = n->fast_out(i);
+              if (store->is_Store() && store->in(0) != NULL) {
+                Node* ctrl = store->in(0);
+                while(!(ctrl == ini || ctrl == alloc || ctrl == NULL ||
+                        ctrl == C->root() || ctrl == C->top() || ctrl->is_Region() ||
+                        ctrl->is_IfTrue() || ctrl->is_IfFalse())) {
+                   ctrl = ctrl->in(0);
+                }
+                if (ctrl == ini || ctrl == alloc) {
+                  value = store->in(MemNode::ValueIn);
+                  break;
+                }
+              }
+            }
+          }
+        }
+        if (value == NULL || value != ptnode_adr(value->_idx)->_node) {
+          // A field's initializing value was not recorded. Add NULL.
+          uint null_idx = UseCompressedOops ? _noop_null : _oop_null;
+          add_pointsto_edge(nidx, null_idx);
+        }
+      }
+    }
+  }
+
+  // An object is not scalar replaceable if the field which may point
+  // to it has unknown offset (unknown element of an array of objects).
+  //
+  if (offset == Type::OffsetBot) {
+    uint e_cnt = ptn->edge_count();
+    for (uint ei = 0; ei < e_cnt; ei++) {
+      uint npi = ptn->edge_target(ei);
+      set_escape_state(npi, PointsToNode::ArgEscape);
+      ptnode_adr(npi)->_scalar_replaceable = false;
+    }
+  }
+
+  // Currently an object is not scalar replaceable if a LoadStore node
+  // access its field since the field value is unknown after it.
+  //
+  bool has_LoadStore = false;
+  for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
+    Node *use = n->fast_out(i);
+    if (use->is_LoadStore()) {
+      has_LoadStore = true;
+      break;
+    }
+  }
+  // An object is not scalar replaceable if the address points
+  // to unknown field (unknown element for arrays, offset is OffsetBot).
+  //
+  // Or the address may point to more then one object. This may produce
+  // the false positive result (set scalar_replaceable to false)
+  // since the flow-insensitive escape analysis can't separate
+  // the case when stores overwrite the field's value from the case
+  // when stores happened on different control branches.
+  //
+  if (ptset_size > 1 || ptset_size != 0 &&
+      (has_LoadStore || offset == Type::OffsetBot)) {
+    for( VectorSetI j(&ptset); j.test(); ++j ) {
+      set_escape_state(j.elem, PointsToNode::ArgEscape);
+      ptnode_adr(j.elem)->_scalar_replaceable = false;
+    }
+  }
+}
+
 void ConnectionGraph::process_call_arguments(CallNode *call, PhaseTransform *phase) {
 
     switch (call->Opcode()) {
@@ -1657,6 +1728,7 @@ void ConnectionGraph::process_call_arguments(CallNode *call, PhaseTransform *pha
       assert(false, "should be done already");
       break;
 #endif
+    case Op_CallLeaf:
     case Op_CallLeafNoFP:
     {
       // Stub calls, objects do not escape but they are not scale replaceable.
@@ -1667,9 +1739,23 @@ void ConnectionGraph::process_call_arguments(CallNode *call, PhaseTransform *pha
         const Type* at = d->field_at(i);
         Node *arg = call->in(i)->uncast();
         const Type *aat = phase->type(arg);
-        if (!arg->is_top() && at->isa_ptr() && aat->isa_ptr()) {
+        if (!arg->is_top() && at->isa_ptr() && aat->isa_ptr() &&
+            ptnode_adr(arg->_idx)->escape_state() < PointsToNode::ArgEscape) {
+
           assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
                  aat->isa_ptr() != NULL, "expecting an Ptr");
+#ifdef ASSERT
+          if (!(call->Opcode() == Op_CallLeafNoFP &&
+                call->as_CallLeaf()->_name != NULL &&
+                (strstr(call->as_CallLeaf()->_name, "arraycopy")  != 0) ||
+                call->as_CallLeaf()->_name != NULL &&
+                (strcmp(call->as_CallLeaf()->_name, "g1_wb_pre")  == 0 ||
+                 strcmp(call->as_CallLeaf()->_name, "g1_wb_post") == 0 ))
+          ) {
+            call->dump();
+            assert(false, "EA: unexpected CallLeaf");
+          }
+#endif
           set_escape_state(arg->_idx, PointsToNode::ArgEscape);
           if (arg->is_AddP()) {
             //
@@ -1706,10 +1792,11 @@ void ConnectionGraph::process_call_arguments(CallNode *call, PhaseTransform *pha
         for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
           const Type* at = d->field_at(i);
           int k = i - TypeFunc::Parms;
-
-          if (at->isa_oopptr() != NULL) {
           Node *arg = call->in(i)->uncast();
 
+          if (at->isa_oopptr() != NULL &&
+              ptnode_adr(arg->_idx)->escape_state() < PointsToNode::ArgEscape) {
+
             bool global_escapes = false;
             bool fields_escapes = false;
             if (!call_analyzer->is_arg_stack(k)) {
@@ -1942,20 +2029,23 @@ void ConnectionGraph::record_for_escape_analysis(Node *n, PhaseTransform *phase)
       record_for_optimizer(n);
       _processed.set(n->_idx);
     } else {
-      // Have to process call's arguments first.
+      // Don't mark as processed since call's arguments have to be processed.
       PointsToNode::NodeType nt = PointsToNode::UnknownType;
+      PointsToNode::EscapeState es = PointsToNode::UnknownEscape;
 
       // Check if a call returns an object.
       const TypeTuple *r = n->as_Call()->tf()->range();
-      if (n->is_CallStaticJava() && r->cnt() > TypeFunc::Parms &&
+      if (r->cnt() > TypeFunc::Parms &&
+          r->field_at(TypeFunc::Parms)->isa_ptr() &&
           n->as_Call()->proj_out(TypeFunc::Parms) != NULL) {
-        // Note:  use isa_ptr() instead of isa_oopptr() here because
-        //        the _multianewarray functions return a TypeRawPtr.
-        if (r->field_at(TypeFunc::Parms)->isa_ptr() != NULL) {
         nt = PointsToNode::JavaObject;
+        if (!n->is_CallStaticJava()) {
+          // Since the called mathod is statically unknown assume
+          // the worst case that the returned value globally escapes.
+          es = PointsToNode::GlobalEscape;
         }
       }
-      add_node(n, nt, PointsToNode::UnknownEscape, false);
+      add_node(n, nt, es, false);
     }
     return;
   }
@@ -2088,18 +2178,27 @@ void ConnectionGraph::record_for_escape_analysis(Node *n, PhaseTransform *phase)
     }
     case Op_Proj:
     {
-      // we are only interested in the result projection from a call
+      // we are only interested in the oop result projection from a call
       if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() ) {
+        const TypeTuple *r = n->in(0)->as_Call()->tf()->range();
+        assert(r->cnt() > TypeFunc::Parms, "sanity");
+        if (r->field_at(TypeFunc::Parms)->isa_ptr() != NULL) {
           add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
+          int ti = n->in(0)->_idx;
+          // The call may not be registered yet (since not all its inputs are registered)
+          // if this is the projection from backbranch edge of Phi.
+          if (ptnode_adr(ti)->node_type() != PointsToNode::UnknownType) {
             process_call_result(n->as_Proj(), phase);
+          }
           if (!_processed.test(n->_idx)) {
             // The call's result may need to be processed later if the call
             // returns it's argument and the argument is not processed yet.
             _delayed_worklist.push(n);
           }
-      } else {
-        _processed.set(n->_idx);
+          break;
         }
+      }
+      _processed.set(n->_idx);
       break;
     }
     case Op_Return:
@@ -2160,6 +2259,15 @@ void ConnectionGraph::record_for_escape_analysis(Node *n, PhaseTransform *phase)
       }
       break;
     }
+    case Op_AryEq:
+    case Op_StrComp:
+    case Op_StrEquals:
+    case Op_StrIndexOf:
+    {
+      // char[] arrays passed to string intrinsics are not scalar replaceable.
+      add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
+      break;
+    }
     case Op_ThreadLocal:
     {
       add_node(n, PointsToNode::JavaObject, PointsToNode::ArgEscape, true);
@@ -2174,6 +2282,7 @@ void ConnectionGraph::record_for_escape_analysis(Node *n, PhaseTransform *phase)
 
 void ConnectionGraph::build_connection_graph(Node *n, PhaseTransform *phase) {
   uint n_idx = n->_idx;
+  assert(ptnode_adr(n_idx)->_node != NULL, "node should be registered");
 
   // Don't set processed bit for AddP, LoadP, StoreP since
   // they may need more then one pass to process.
@@ -2211,6 +2320,7 @@ void ConnectionGraph::build_connection_graph(Node *n, PhaseTransform *phase) {
     case Op_DecodeN:
     {
       int ti = n->in(1)->_idx;
+      assert(ptnode_adr(ti)->node_type() != PointsToNode::UnknownType, "all nodes should be registered");
       if (ptnode_adr(ti)->node_type() == PointsToNode::JavaObject) {
         add_pointsto_edge(n_idx, ti);
       } else {
@@ -2250,7 +2360,6 @@ void ConnectionGraph::build_connection_graph(Node *n, PhaseTransform *phase) {
 #endif
 
       Node* adr = n->in(MemNode::Address)->uncast();
-      const Type *adr_type = phase->type(adr);
       Node* adr_base;
       if (adr->is_AddP()) {
         adr_base = get_addp_base(adr);
@@ -2302,13 +2411,19 @@ void ConnectionGraph::build_connection_graph(Node *n, PhaseTransform *phase) {
     }
     case Op_Proj:
     {
-      // we are only interested in the result projection from a call
+      // we are only interested in the oop result projection from a call
       if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() ) {
+        assert(ptnode_adr(n->in(0)->_idx)->node_type() != PointsToNode::UnknownType,
+               "all nodes should be registered");
+        const TypeTuple *r = n->in(0)->as_Call()->tf()->range();
+        assert(r->cnt() > TypeFunc::Parms, "sanity");
+        if (r->field_at(TypeFunc::Parms)->isa_ptr() != NULL) {
           process_call_result(n->as_Proj(), phase);
           assert(_processed.test(n_idx), "all call results should be processed");
-      } else {
-        assert(false, "Op_Proj");
+          break;
         }
+      }
+      assert(false, "Op_Proj");
       break;
     }
     case Op_Return:
@@ -2320,6 +2435,7 @@ void ConnectionGraph::build_connection_graph(Node *n, PhaseTransform *phase) {
       }
 #endif
       int ti = n->in(TypeFunc::Parms)->_idx;
+      assert(ptnode_adr(ti)->node_type() != PointsToNode::UnknownType, "node should be registered");
       if (ptnode_adr(ti)->node_type() == PointsToNode::JavaObject) {
         add_pointsto_edge(n_idx, ti);
       } else {
@@ -2354,14 +2470,38 @@ void ConnectionGraph::build_connection_graph(Node *n, PhaseTransform *phase) {
       }
       break;
     }
+    case Op_AryEq:
+    case Op_StrComp:
+    case Op_StrEquals:
+    case Op_StrIndexOf:
+    {
+      // char[] arrays passed to string intrinsic do not escape but
+      // they are not scalar replaceable. Adjust escape state for them.
+      // Start from in(2) edge since in(1) is memory edge.
+      for (uint i = 2; i < n->req(); i++) {
+        Node* adr = n->in(i)->uncast();
+        const Type *at = phase->type(adr);
+        if (!adr->is_top() && at->isa_ptr()) {
+          assert(at == Type::TOP || at == TypePtr::NULL_PTR ||
+                 at->isa_ptr() != NULL, "expecting an Ptr");
+          if (adr->is_AddP()) {
+            adr = get_addp_base(adr);
+          }
+          // Mark as ArgEscape everything "adr" could point to.
+          set_escape_state(adr->_idx, PointsToNode::ArgEscape);
+        }
+      }
+      _processed.set(n_idx);
+      break;
+    }
     case Op_ThreadLocal:
     {
       assert(false, "Op_ThreadLocal");
       break;
     }
     default:
-      ;
-      // nothing to do
+      // This method should be called only for EA specific nodes.
+      ShouldNotReachHere();
   }
 }
 

src/share/vm/opto/escape.hpp

@@ -210,6 +210,8 @@ private:
   Unique_Node_List  _delayed_worklist; // Nodes to be processed before
                                        // the call build_connection_graph().
 
+  GrowableArray<MergeMemNode *>  _mergemem_worklist; // List of all MergeMem nodes
+
   VectorSet                _processed; // Records which nodes have been
                                        // processed.
 
@@ -315,6 +317,9 @@ private:
   // Set the escape state of a node
   void set_escape_state(uint ni, PointsToNode::EscapeState es);
 
+  // Search for objects which are not scalar replaceable.
+  void verify_escape_state(int nidx, VectorSet& ptset, PhaseTransform* phase);
+
 public:
   ConnectionGraph(Compile *C);
 

src/share/vm/opto/lcm.cpp

@@ -616,8 +616,9 @@ bool Block::schedule_local(PhaseCFG *cfg, Matcher &matcher, int *ready_cnt, Vect
           assert(cfg->_bbs[oop_store->_idx]->_dom_depth <= this->_dom_depth, "oop_store must dominate card-mark");
         }
       }
-      if( n->is_Mach() && n->as_Mach()->ideal_Opcode() == Op_MemBarAcquire &&
-          n->req() > TypeFunc::Parms ) {
+      if( n->is_Mach() && n->req() > TypeFunc::Parms &&
+          (n->as_Mach()->ideal_Opcode() == Op_MemBarAcquire ||
+           n->as_Mach()->ideal_Opcode() == Op_MemBarVolatile) ) {
         // MemBarAcquire could be created without Precedent edge.
         // del_req() replaces the specified edge with the last input edge
         // and then removes the last edge. If the specified edge > number of

src/share/vm/opto/macro.cpp

@@ -316,6 +316,21 @@ static Node *scan_mem_chain(Node *mem, int alias_idx, int offset, Node *start_me
         assert(adr_idx == Compile::AliasIdxRaw, "address must match or be raw");
       }
       mem = mem->in(MemNode::Memory);
+    } else if (mem->is_ClearArray()) {
+      if (!ClearArrayNode::step_through(&mem, alloc->_idx, phase)) {
+        // Can not bypass initialization of the instance
+        // we are looking.
+        debug_only(intptr_t offset;)
+        assert(alloc == AllocateNode::Ideal_allocation(mem->in(3), phase, offset), "sanity");
+        InitializeNode* init = alloc->as_Allocate()->initialization();
+        // We are looking for stored value, return Initialize node
+        // or memory edge from Allocate node.
+        if (init != NULL)
+          return init;
+        else
+          return alloc->in(TypeFunc::Memory); // It will produce zero value (see callers).
+      }
+      // Otherwise skip it (the call updated 'mem' value).
     } else if (mem->Opcode() == Op_SCMemProj) {
       assert(mem->in(0)->is_LoadStore(), "sanity");
       const TypePtr* atype = mem->in(0)->in(MemNode::Address)->bottom_type()->is_ptr();
@@ -823,6 +838,18 @@ void PhaseMacroExpand::process_users_of_allocation(AllocateNode *alloc) {
           Node *n = use->last_out(k);
           uint oc2 = use->outcnt();
           if (n->is_Store()) {
+#ifdef ASSERT
+            // Verify that there is no dependent MemBarVolatile nodes,
+            // they should be removed during IGVN, see MemBarNode::Ideal().
+            for (DUIterator_Fast pmax, p = n->fast_outs(pmax);
+                                       p < pmax; p++) {
+              Node* mb = n->fast_out(p);
+              assert(mb->is_Initialize() || !mb->is_MemBar() ||
+                     mb->req() <= MemBarNode::Precedent ||
+                     mb->in(MemBarNode::Precedent) != n,
+                     "MemBarVolatile should be eliminated for non-escaping object");
+            }
+#endif
             _igvn.replace_node(n, n->in(MemNode::Memory));
           } else {
             eliminate_card_mark(n);

src/share/vm/opto/memnode.cpp

@@ -123,6 +123,13 @@ Node *MemNode::optimize_simple_memory_chain(Node *mchain, const TypePtr *t_adr,
       } else {
         assert(false, "unexpected projection");
       }
+    } else if (result->is_ClearArray()) {
+      if (!ClearArrayNode::step_through(&result, instance_id, phase)) {
+        // Can not bypass initialization of the instance
+        // we are looking for.
+        break;
+      }
+      // Otherwise skip it (the call updated 'result' value).
     } else if (result->is_MergeMem()) {
       result = step_through_mergemem(phase, result->as_MergeMem(), t_adr, NULL, tty);
     }
@@ -537,6 +544,15 @@ Node* MemNode::find_previous_store(PhaseTransform* phase) {
       } else if (mem->is_Proj() && mem->in(0)->is_MemBar()) {
         mem = mem->in(0)->in(TypeFunc::Memory);
         continue;           // (a) advance through independent MemBar memory
+      } else if (mem->is_ClearArray()) {
+        if (ClearArrayNode::step_through(&mem, (uint)addr_t->instance_id(), phase)) {
+          // (the call updated 'mem' value)
+          continue;         // (a) advance through independent allocation memory
+        } else {
+          // Can not bypass initialization of the instance
+          // we are looking for.
+          return mem;
+        }
       } else if (mem->is_MergeMem()) {
         int alias_idx = phase->C->get_alias_index(adr_type());
         mem = mem->as_MergeMem()->memory_at(alias_idx);
@@ -2454,6 +2470,31 @@ Node *ClearArrayNode::Ideal(PhaseGVN *phase, bool can_reshape){
   return mem;
 }
 
+//----------------------------step_through----------------------------------
+// Return allocation input memory edge if it is different instance
+// or itself if it is the one we are looking for.
+bool ClearArrayNode::step_through(Node** np, uint instance_id, PhaseTransform* phase) {
+  Node* n = *np;
+  assert(n->is_ClearArray(), "sanity");
+  intptr_t offset;
+  AllocateNode* alloc = AllocateNode::Ideal_allocation(n->in(3), phase, offset);
+  // This method is called only before Allocate nodes are expanded during
+  // macro nodes expansion. Before that ClearArray nodes are only generated
+  // in LibraryCallKit::generate_arraycopy() which follows allocations.
+  assert(alloc != NULL, "should have allocation");
+  if (alloc->_idx == instance_id) {
+    // Can not bypass initialization of the instance we are looking for.
+    return false;
+  }
+  // Otherwise skip it.
+  InitializeNode* init = alloc->initialization();
+  if (init != NULL)
+    *np = init->in(TypeFunc::Memory);
+  else
+    *np = alloc->in(TypeFunc::Memory);
+  return true;
+}
+
 //----------------------------clear_memory-------------------------------------
 // Generate code to initialize object storage to zero.
 Node* ClearArrayNode::clear_memory(Node* ctl, Node* mem, Node* dest,
@@ -2627,7 +2668,30 @@ MemBarNode* MemBarNode::make(Compile* C, int opcode, int atp, Node* pn) {
 // Return a node which is more "ideal" than the current node.  Strip out
 // control copies
 Node *MemBarNode::Ideal(PhaseGVN *phase, bool can_reshape) {
-  return remove_dead_region(phase, can_reshape) ? this : NULL;
+  if (remove_dead_region(phase, can_reshape)) return this;
+
+  // Eliminate volatile MemBars for scalar replaced objects.
+  if (can_reshape && req() == (Precedent+1) &&
+      (Opcode() == Op_MemBarAcquire || Opcode() == Op_MemBarVolatile)) {
+    // Volatile field loads and stores.
+    Node* my_mem = in(MemBarNode::Precedent);
+    if (my_mem != NULL && my_mem->is_Mem()) {
+      const TypeOopPtr* t_oop = my_mem->in(MemNode::Address)->bottom_type()->isa_oopptr();
+      // Check for scalar replaced object reference.
+      if( t_oop != NULL && t_oop->is_known_instance_field() &&
+          t_oop->offset() != Type::OffsetBot &&
+          t_oop->offset() != Type::OffsetTop) {
+        // Replace MemBar projections by its inputs.
+        PhaseIterGVN* igvn = phase->is_IterGVN();
+        igvn->replace_node(proj_out(TypeFunc::Memory), in(TypeFunc::Memory));
+        igvn->replace_node(proj_out(TypeFunc::Control), in(TypeFunc::Control));
+        // Must return either the original node (now dead) or a new node
+        // (Do not return a top here, since that would break the uniqueness of top.)
+        return new (phase->C, 1) ConINode(TypeInt::ZERO);
+      }
+    }
+  }
+  return NULL;
 }
 
 //------------------------------Value------------------------------------------

src/share/vm/opto/memnode.hpp

@@ -717,7 +717,10 @@ public:
 //------------------------------ClearArray-------------------------------------
 class ClearArrayNode: public Node {
 public:
-  ClearArrayNode( Node *ctrl, Node *arymem, Node *word_cnt, Node *base ) : Node(ctrl,arymem,word_cnt,base) {}
+  ClearArrayNode( Node *ctrl, Node *arymem, Node *word_cnt, Node *base )
+    : Node(ctrl,arymem,word_cnt,base) {
+    init_class_id(Class_ClearArray);
+  }
   virtual int         Opcode() const;
   virtual const Type *bottom_type() const { return Type::MEMORY; }
   // ClearArray modifies array elements, and so affects only the
@@ -743,6 +746,9 @@ public:
                             Node* start_offset,
                             Node* end_offset,
                             PhaseGVN* phase);
+  // Return allocation input memory edge if it is different instance
+  // or itself if it is the one we are looking for.
+  static bool step_through(Node** np, uint instance_id, PhaseTransform* phase);
 };
 
 //------------------------------StrComp-------------------------------------

src/share/vm/opto/node.hpp

@@ -47,6 +47,7 @@ class CallStaticJavaNode;
 class CatchNode;
 class CatchProjNode;
 class CheckCastPPNode;
+class ClearArrayNode;
 class CmpNode;
 class CodeBuffer;
 class ConstraintCastNode;
@@ -599,8 +600,9 @@ public:
     DEFINE_CLASS_ID(BoxLock,  Node, 10)
     DEFINE_CLASS_ID(Add,      Node, 11)
     DEFINE_CLASS_ID(Mul,      Node, 12)
+    DEFINE_CLASS_ID(ClearArray, Node, 13)
 
-    _max_classes  = ClassMask_Mul
+    _max_classes  = ClassMask_ClearArray
   };
   #undef DEFINE_CLASS_ID
 
@@ -698,6 +700,7 @@ public:
   DEFINE_CLASS_QUERY(CatchProj)
   DEFINE_CLASS_QUERY(CheckCastPP)
   DEFINE_CLASS_QUERY(ConstraintCast)
+  DEFINE_CLASS_QUERY(ClearArray)
   DEFINE_CLASS_QUERY(CMove)
   DEFINE_CLASS_QUERY(Cmp)
   DEFINE_CLASS_QUERY(CountedLoop)

src/share/vm/opto/parse3.cpp

@@ -240,19 +240,19 @@ void Parse::do_put_xxx(const TypePtr* obj_type, Node* obj, ciField* field, bool
     // membar is dependent on the store, keeping any other membars generated
     // below from floating up past the store.
     int adr_idx = C->get_alias_index(adr_type);
-    insert_mem_bar_volatile(Op_MemBarVolatile, adr_idx);
+    insert_mem_bar_volatile(Op_MemBarVolatile, adr_idx, store);
 
     // Now place a membar for AliasIdxBot for the unknown yet-to-be-parsed
     // volatile alias indices. Skip this if the membar is redundant.
     if (adr_idx != Compile::AliasIdxBot) {
-      insert_mem_bar_volatile(Op_MemBarVolatile, Compile::AliasIdxBot);
+      insert_mem_bar_volatile(Op_MemBarVolatile, Compile::AliasIdxBot, store);
     }
 
     // Finally, place alias-index-specific membars for each volatile index
     // that isn't the adr_idx membar. Typically there's only 1 or 2.
     for( int i = Compile::AliasIdxRaw; i < C->num_alias_types(); i++ ) {
       if (i != adr_idx && C->alias_type(i)->is_volatile()) {
-        insert_mem_bar_volatile(Op_MemBarVolatile, i);
+        insert_mem_bar_volatile(Op_MemBarVolatile, i, store);
       }
     }
   }

test/compiler/6895383/Test.java

+/*
+ * Copyright 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.
+ *
+ */
+
+/**
+ * @test
+ * @bug 6895383
+ * @summary JCK test throws NPE for method compiled with Escape Analysis
+ *
+ * @run main/othervm -Xcomp Test
+ */
+
+public class Test {
+    public static void main(String argv[]) {
+        Test test = new Test();
+        test.testRemove1_IndexOutOfBounds();
+        test.testAddAll1_IndexOutOfBoundsException();
+    }
+
+    public void testRemove1_IndexOutOfBounds() {
+        CopyOnWriteArrayList c = new CopyOnWriteArrayList();
+    }
+
+    public void testAddAll1_IndexOutOfBoundsException() {
+        try {
+            CopyOnWriteArrayList c = new CopyOnWriteArrayList();
+            c.addAll(-1, new LinkedList()); // should throw IndexOutOfBoundsException
+        } catch (IndexOutOfBoundsException e) {
+        }
+    }
+}