Index: include/clang/AST/Decl.h
===================================================================
--- include/clang/AST/Decl.h	(revision 173459)
+++ include/clang/AST/Decl.h	(working copy)
@@ -2930,6 +2930,10 @@
   /// HasObjectMember - This is true if this struct has at least one member
   /// containing an Objective-C object pointer type.
   bool HasObjectMember : 1;
+  
+  /// HasVolatileMember - This is true if struct has at least one member of
+  /// 'volatile' type.
+  bool HasVolatileMember : 1;
 
   /// \brief Whether the field declarations of this record have been loaded
   /// from external storage. To avoid unnecessary deserialization of
@@ -2986,6 +2990,9 @@
   bool hasObjectMember() const { return HasObjectMember; }
   void setHasObjectMember (bool val) { HasObjectMember = val; }
 
+  bool hasVolatileMember() const { return HasVolatileMember; }
+  void setHasVolatileMember (bool val) { HasVolatileMember = val; }
+  
   /// \brief Determines whether this declaration represents the
   /// injected class name.
   ///
Index: lib/AST/Decl.cpp
===================================================================
--- lib/AST/Decl.cpp	(revision 173459)
+++ lib/AST/Decl.cpp	(working copy)
@@ -2734,6 +2734,7 @@
   HasFlexibleArrayMember = false;
   AnonymousStructOrUnion = false;
   HasObjectMember = false;
+    HasVolatileMember = false;
   LoadedFieldsFromExternalStorage = false;
   assert(classof(static_cast<Decl*>(this)) && "Invalid Kind!");
 }
Index: lib/AST/DeclCXX.cpp
===================================================================
--- lib/AST/DeclCXX.cpp	(revision 173459)
+++ lib/AST/DeclCXX.cpp	(working copy)
@@ -301,6 +301,9 @@
     // has an Objective-C object member.
     if (BaseClassDecl->hasObjectMember())
       setHasObjectMember(true);
+    
+    if (BaseClassDecl->hasVolatileMember())
+      setHasVolatileMember(true);
 
     // Keep track of the presence of mutable fields.
     if (BaseClassDecl->hasMutableFields())
@@ -751,6 +754,8 @@
           data().HasIrrelevantDestructor = false;
         if (FieldRec->hasObjectMember())
           setHasObjectMember(true);
+        if (FieldRec->hasVolatileMember())
+          setHasVolatileMember(true);
 
         // C++0x [class]p7:
         //   A standard-layout class is a class that:
Index: lib/CodeGen/CGExprAgg.cpp
===================================================================
--- lib/CodeGen/CGExprAgg.cpp	(revision 173459)
+++ lib/CodeGen/CGExprAgg.cpp	(working copy)
@@ -792,6 +792,11 @@
     AggValueSlot::forLValue(LHS, AggValueSlot::IsDestructed, 
                             needsGC(E->getLHS()->getType()),
                             AggValueSlot::IsAliased);
+  // A non-volatile aggregate destination might have volatile member.
+  if (!LHSSlot.isVolatile() &&
+      CGF.IsAggrVolatile(E->getLHS()->getType()))
+    LHSSlot.setVolatile(true);
+      
   CGF.EmitAggExpr(E->getRHS(), LHSSlot);
 
   // Copy into the destination if the assignment isn't ignored.
Index: lib/CodeGen/CGValue.h
===================================================================
--- lib/CodeGen/CGValue.h	(revision 173459)
+++ lib/CodeGen/CGValue.h	(working copy)
@@ -412,6 +412,10 @@
     return Quals.hasVolatile();
   }
 
+  void setVolatile(bool flag) {
+    Quals.setVolatile(flag);
+  }
+  
   Qualifiers::ObjCLifetime getObjCLifetime() const {
     return Quals.getObjCLifetime();
   }
Index: lib/CodeGen/CodeGenFunction.h
===================================================================
--- lib/CodeGen/CodeGenFunction.h	(revision 173459)
+++ lib/CodeGen/CodeGenFunction.h	(working copy)
@@ -1665,14 +1665,23 @@
   void EmitExprAsInit(const Expr *init, const ValueDecl *D,
                       LValue lvalue, bool capturedByInit);
 
+  /// IsAggrVolatile - returns true if aggregate type has a volatile
+  /// member.
+  bool IsAggrVolatile(QualType T) {
+    if (const RecordType *RT = T->getAs<RecordType>())
+      if (const RecordDecl *RD = cast<RecordDecl>(RT->getDecl()))
+        return RD->hasVolatileMember();
+    return false;
+  }
   /// EmitAggregateCopy - Emit an aggrate assignment.
   ///
   /// The difference to EmitAggregateCopy is that tail padding is not copied.
   /// This is required for correctness when assigning non-POD structures in C++.
   void EmitAggregateAssign(llvm::Value *DestPtr, llvm::Value *SrcPtr,
-                           QualType EltTy, bool isVolatile=false,
-                           CharUnits Alignment = CharUnits::Zero()) {
-    EmitAggregateCopy(DestPtr, SrcPtr, EltTy, isVolatile, Alignment, true);
+                           QualType EltTy) {
+    bool IsVolatile = IsAggrVolatile(EltTy);
+    EmitAggregateCopy(DestPtr, SrcPtr, EltTy, IsVolatile, CharUnits::Zero(),
+                      true);
   }
 
   /// EmitAggregateCopy - Emit an aggrate copy.
Index: lib/Sema/SemaDecl.cpp
===================================================================
--- lib/Sema/SemaDecl.cpp	(revision 173459)
+++ lib/Sema/SemaDecl.cpp	(working copy)
@@ -10462,6 +10462,8 @@
       }
       if (Record && FDTTy->getDecl()->hasObjectMember())
         Record->setHasObjectMember(true);
+      if (Record && FDTTy->getDecl()->hasVolatileMember())
+        Record->setHasVolatileMember(true);
     } else if (FDTy->isObjCObjectType()) {
       /// A field cannot be an Objective-c object
       Diag(FD->getLocation(), diag::err_statically_allocated_object)
@@ -10508,6 +10510,8 @@
         }
       }
     }
+    if (Record && FD->getType().isVolatileQualified())
+      Record->setHasVolatileMember(true);
     // Keep track of the number of named members.
     if (FD->getIdentifier())
       ++NumNamedMembers;
Index: lib/Serialization/ASTReaderDecl.cpp
===================================================================
--- lib/Serialization/ASTReaderDecl.cpp	(revision 173459)
+++ lib/Serialization/ASTReaderDecl.cpp	(working copy)
@@ -475,6 +475,7 @@
   RD->setHasFlexibleArrayMember(Record[Idx++]);
   RD->setAnonymousStructOrUnion(Record[Idx++]);
   RD->setHasObjectMember(Record[Idx++]);
+  RD->setHasVolatileMember(Record[Idx++]);
 }
 
 void ASTDeclReader::VisitValueDecl(ValueDecl *VD) {
Index: lib/Serialization/ASTWriterDecl.cpp
===================================================================
--- lib/Serialization/ASTWriterDecl.cpp	(revision 173459)
+++ lib/Serialization/ASTWriterDecl.cpp	(working copy)
@@ -263,6 +263,7 @@
   Record.push_back(D->hasFlexibleArrayMember());
   Record.push_back(D->isAnonymousStructOrUnion());
   Record.push_back(D->hasObjectMember());
+  Record.push_back(D->hasVolatileMember());
 
   if (!D->hasAttrs() &&
       !D->isImplicit() &&
@@ -1456,6 +1457,7 @@
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // FlexibleArrayMember
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // AnonymousStructUnion
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // hasObjectMember
+  Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // hasVolatileMember
   // DC
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // LexicalOffset
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // VisibleOffset
Index: test/CodeGen/no-opt-volatile-memcpy.c
===================================================================
--- test/CodeGen/no-opt-volatile-memcpy.c	(revision 0)
+++ test/CodeGen/no-opt-volatile-memcpy.c	(working copy)
@@ -0,0 +1,32 @@
+// RUN: %clang_cc1 -O -triple=x86_64-apple-darwin  -emit-llvm -o - %s | FileCheck %s
+// rdar://11861085
+
+struct s {
+  char filler [128];
+  volatile int x;
+};
+
+struct s gs;
+
+void foo (void) {
+  struct s ls;
+  ls = ls;
+  gs = gs;
+  ls = gs;
+}
+// CHECK: call void @llvm.memcpy
+// CHECK: call void @llvm.memcpy
+// CHECK: call void @llvm.memcpy
+
+struct s1 {
+  struct s y;
+};
+
+struct s1 s;
+
+void fee (void) {
+  s = s;
+  s.y = gs;
+}
+// CHECK: call void @llvm.memcpy
+// CHECK: call void @llvm.memcpy
Index: test/CodeGenCXX/no-opt-volatile-memcpy.cpp
===================================================================
--- test/CodeGenCXX/no-opt-volatile-memcpy.cpp	(revision 0)
+++ test/CodeGenCXX/no-opt-volatile-memcpy.cpp	(working copy)
@@ -0,0 +1,44 @@
+// RUN: %clang_cc1 -O -triple=x86_64-apple-darwin  -emit-llvm -o - %s | FileCheck %s
+// rdar://11861085
+
+struct s {
+  char filler [128];
+  volatile int x;
+};
+
+struct s gs;
+
+void foo (void) {
+  struct s ls;
+  ls = ls;
+  gs = gs;
+  ls = gs;
+}
+// CHECK: call void @llvm.memcpy
+// CHECK: call void @llvm.memcpy
+// CHECK: call void @llvm.memcpy
+
+struct s1 {
+  struct s y;
+};
+
+struct s1 s;
+
+void fee (void) {
+  s = s;
+  s.y = gs;
+}
+// CHECK: call void @llvm.memcpy
+// CHECK: call void @llvm.memcpy
+
+
+struct d : s1 {
+};
+
+d gd;
+
+void gorf(void) {
+  gd = gd;
+}
+// CHECK: call void @llvm.memcpy
+