Index: lib/CodeGen/SelectionDAG/TargetLowering.cpp
===================================================================
--- lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -1384,6 +1384,31 @@
           SDValue C = DAG.getConstant(C1.trunc(MinBits), dl, MinVT);
           return DAG.getSetCC(dl, VT, Trunc, C, Cond);
         }
+
+        // If truncating the setcc operands is not desirable, we can still
+        // simplify the expression in some cases.
+
+        // setcc ([sz]ext (setcc x, y, cc)), 0, setne) -> setcc (x, y, cc)
+        // setcc ([sz]ext (setcc x, y, cc)), 0, seteq) -> setcc (x, Y, inverse(cc))
+        SDValue TopSetCC = N0->getOperand(0);
+        if (TopSetCC.getValueType() == MVT::i1 && VT == MVT::i1 &&
+            TopSetCC.getOpcode() == ISD::SETCC &&
+            N1C->isNullValue() &&
+            (N0->getOpcode() == ISD::ZERO_EXTEND ||
+             N0->getOpcode() == ISD::SIGN_EXTEND)) {
+
+          if (Cond == ISD::SETNE)
+            return TopSetCC;
+
+          assert (Cond == ISD::SETEQ);
+          ISD::CondCode InvCond = ISD::getSetCCInverse(
+              cast<CondCodeSDNode>(TopSetCC.getOperand(2))->get(),
+              TopSetCC.getOperand(0).getValueType().isInteger());
+          return DAG.getSetCC(dl, VT, TopSetCC.getOperand(0),
+                                      TopSetCC.getOperand(1),
+                                      InvCond);
+
+        }
       }
     }