diff --git a/clang/AST/Expr.cpp b/clang/AST/Expr.cpp
index d7b388f49c16..57de307cb2ca 100644
--- a/clang/AST/Expr.cpp
+++ b/clang/AST/Expr.cpp
@@ -135,23 +135,19 @@ bool Expr::isLvalue() {
   if (TR->isIncompleteType() && TR->isVoidType())
     return false;
   
-  // now, check the expression
+  // the type looks fine, now check the expression
   switch (getStmtClass()) {
   case StringLiteralClass: // C99 6.5.1p4
     return true;
-  case ArraySubscriptExprClass:
+  case ArraySubscriptExprClass: // C99 6.5.3p4 (e1[e2] == (*((e1)+(e2))))
     return true;
   case DeclRefExprClass: // C99 6.5.1p2
-    const DeclRefExpr *d = cast<DeclRefExpr>(this);
-    return isa<VarDecl>(d->getDecl());
+    return isa<VarDecl>(cast<DeclRefExpr>(this)->getDecl());
   case MemberExprClass: // C99 6.5.2.3p4
     const MemberExpr *m = cast<MemberExpr>(this);
-    if (m->isArrow())
-      return true;
-    return m->getBase()->isLvalue();
+    return m->isArrow() ? true : m->getBase()->isLvalue();
   case UnaryOperatorClass: // C99 6.5.3p4
-    const UnaryOperator *u = cast<UnaryOperator>(this);
-    return u->getOpcode() == UnaryOperator::Deref;
+    return cast<UnaryOperator>(this)->getOpcode() == UnaryOperator::Deref;
   case ParenExprClass: // C99 6.5.1p5
     return cast<ParenExpr>(this)->getSubExpr()->isLvalue();
   default: 
diff --git a/clang/AST/SemaExpr.cpp b/clang/AST/SemaExpr.cpp
index 18fdfbece767..3051f6f40495 100644
--- a/clang/AST/SemaExpr.cpp
+++ b/clang/AST/SemaExpr.cpp
@@ -780,9 +780,9 @@ static Decl *getPrimaryDeclaration(Expr *e) {
 QualType Sema::CheckAddressOfOperand(Expr *op, SourceLocation OpLoc) {
   Decl *dcl = getPrimaryDeclaration(op);
   
-  if (!op->isLvalue()) { // 
-    if (dcl && isa<FunctionDecl>(dcl))
-      ;  // C99 6.5.3.2p1: Allow function designators.
+  if (!op->isLvalue()) { // C99 6.5.3.2p1
+    if (dcl && isa<FunctionDecl>(dcl)) // allow function designators
+      ;  
     else {
       Diag(OpLoc, diag::err_typecheck_invalid_lvalue_addrof);
       return QualType();
diff --git a/clang/Sema/SemaExpr.cpp b/clang/Sema/SemaExpr.cpp
index 18fdfbece767..3051f6f40495 100644
--- a/clang/Sema/SemaExpr.cpp
+++ b/clang/Sema/SemaExpr.cpp
@@ -780,9 +780,9 @@ static Decl *getPrimaryDeclaration(Expr *e) {
 QualType Sema::CheckAddressOfOperand(Expr *op, SourceLocation OpLoc) {
   Decl *dcl = getPrimaryDeclaration(op);
   
-  if (!op->isLvalue()) { // 
-    if (dcl && isa<FunctionDecl>(dcl))
-      ;  // C99 6.5.3.2p1: Allow function designators.
+  if (!op->isLvalue()) { // C99 6.5.3.2p1
+    if (dcl && isa<FunctionDecl>(dcl)) // allow function designators
+      ;  
     else {
       Diag(OpLoc, diag::err_typecheck_invalid_lvalue_addrof);
       return QualType();