Add v4f64 -> v2f32 fp_round support. Also add a testcase to exercise
the legalizer. This commit together with the two previous ones fixes
PR10495.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136654 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index c6dede9..b00b00d 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -966,6 +966,7 @@
 
     setOperationAction(ISD::FP_TO_SINT,         MVT::v8i32, Legal);
     setOperationAction(ISD::SINT_TO_FP,         MVT::v8i32, Legal);
+    setOperationAction(ISD::FP_ROUND,           MVT::v4f32, Legal);
 
     setOperationAction(ISD::CONCAT_VECTORS,     MVT::v4f64,  Custom);
     setOperationAction(ISD::CONCAT_VECTORS,     MVT::v4i64,  Custom);