Add a simple optimization to simplify the input to
truncate and truncstore instructions, based on the 
knowledge that they don't demand the top bits.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@42952 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
index d8dc94e..b54af7d 100644
--- a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -2025,7 +2025,7 @@
       // probably means that we need to integrate dag combiner and legalizer
       // together.
       // We generally can't do this one for long doubles.
-      if (ConstantFPSDNode *CFP =dyn_cast<ConstantFPSDNode>(ST->getValue())) {
+      if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(ST->getValue())) {
         if (CFP->getValueType(0) == MVT::f32) {
           Tmp3 = DAG.getConstant((uint32_t)CFP->getValueAPF().
                                           convertToAPInt().getZExtValue(),