diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index 82cf457dade..fee69a266dc 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -380,6 +380,8 @@ static unsigned AddLiveIn(MachineFunction &MF, unsigned PReg,
 static void
 HowToPassCCCArgument(MVT::ValueType ObjectVT, unsigned NumXMMRegs,
                      unsigned &ObjSize, unsigned &ObjXMMRegs) {
+  NumXMMRegs = 0;
+
   switch (ObjectVT) {
   default: assert(0 && "Unhandled argument type!");
   case MVT::i1:
@@ -774,6 +776,7 @@ HowToPassFastCCArgument(MVT::ValueType ObjectVT,
                         unsigned &ObjXMMRegs) {
   ObjSize = 0;
   NumIntRegs = 0;
+  NumXMMRegs = 0;
 
   switch (ObjectVT) {
   default: assert(0 && "Unhandled argument type!");