diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index 6de6b21c78e..0616513b5ee 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -2675,7 +2675,8 @@ X86TargetLowering::LowerVECTOR_SHUFFLE(SDOperand Op, SelectionDAG &DAG) {
       return Op;
     }
 
-    if (X86::isSHUFPMask(PermMask.Val))
+    if (X86::isSHUFPMask(PermMask.Val) &&
+        MVT::getSizeInBits(VT) != 64)    // Don't do this for MMX.
       return Op;
 
     // Handle v8i16 shuffle high / low shuffle node pair.
@@ -2712,7 +2713,9 @@ X86TargetLowering::LowerVECTOR_SHUFFLE(SDOperand Op, SelectionDAG &DAG) {
     }
   }
 
-  if (NumElems == 4) {
+  if (NumElems == 4 && 
+      // Don't do this for MMX.
+      MVT::getSizeInBits(VT) != 64) {
     MVT::ValueType MaskVT = PermMask.getValueType();
     MVT::ValueType MaskEVT = MVT::getVectorBaseType(MaskVT);
     SmallVector<std::pair<int, int>, 8> Locs;