Fold trunc(any_ext).  This gives stuff like:

27,28c27
<       movzwl %di, %edi
<       movl %edi, %ebx
---
>       movw %di, %bx


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@28137 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 1175f52..b967855 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -2005,7 +2005,8 @@
   if (N0.getOpcode() == ISD::TRUNCATE)
     return DAG.getNode(ISD::TRUNCATE, VT, N0.getOperand(0));
   // fold (truncate (ext x)) -> (ext x) or (truncate x) or x
-  if (N0.getOpcode() == ISD::ZERO_EXTEND || N0.getOpcode() == ISD::SIGN_EXTEND){
+  if (N0.getOpcode() == ISD::ZERO_EXTEND || N0.getOpcode() == ISD::SIGN_EXTEND||
+      N0.getOpcode() == ISD::ANY_EXTEND) {
     if (N0.getValueType() < VT)
       // if the source is smaller than the dest, we still need an extend
       return DAG.getNode(N0.getOpcode(), VT, N0.getOperand(0));