Index: lib/CodeGen/SelectionDAG/DAGCombiner.cpp
===================================================================
--- lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -8609,6 +8609,10 @@
       // if this is the case.
       EVT SVT = getSetCCResultType(N00VT);
 
+      // If we already have the desired type, don't change it.
+      if (SVT == N0.getValueType())
+        return SDValue();
+
       // We know that the # elements of the results is the same as the
       // # elements of the compare (and the # elements of the compare result
       // for that matter).  Check to see that they are the same size.  If so,
Index: lib/Target/X86/X86ISelLowering.cpp
===================================================================
--- lib/Target/X86/X86ISelLowering.cpp
+++ lib/Target/X86/X86ISelLowering.cpp
@@ -39130,6 +39130,14 @@
   EVT InVT = N0.getValueType();
   EVT InSVT = InVT.getScalarType();
 
+  // Generic DAGCombiner previously had a bug that would cause a sign_extend of
+  // setcc to sometimes return the original node and tricked it into thinking
+  // CombineTo was used which prevented the target combines from running.
+  // Earlying out here to avoid regressions.
+  // FIXME: Can we remove this?
+  if (N0.getOpcode() == ISD::SETCC)
+    return SDValue();
+
   // Input type must be a vector and we must be extending legal integer types.
   if (!VT.isVector() || VT.getVectorNumElements() < 2)
     return SDValue();