This is the correct fix for PR1427.  This fixes mmx-shuffle.ll and doesn't
cause other regressions.

llvm-svn: 37160
diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index 6de6b21..0616513 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -2675,7 +2675,8 @@
       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 @@
     }
   }
 
-  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;