Allow bitcasts between valid types of the same size and vector
types if the vector type is legal.

Fixes rdar://9306086


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132420 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 8edbdf0..9a656a7 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -282,6 +282,12 @@
     // Vector/Vector bitcast.
     return DAG.getNode(ISD::BITCAST, DL, ValueVT, Val);
   }
+  
+  // Trivial bitcast if the types are the same size and the destination
+  // vector type is legal.
+  if (PartVT.getSizeInBits() == ValueVT.getSizeInBits() &&
+      TLI.isTypeLegal(ValueVT))
+    return DAG.getNode(ISD::BITCAST, DL, ValueVT, Val);
 
   assert(ValueVT.getVectorElementType() == PartVT &&
          ValueVT.getVectorNumElements() == 1 &&