[FPEnv][LegalizeTypes] Make ScalarizeVecOp_STRICT_FP_ROUND do its own replacements...

The caller will assert for nodes with more than 2 results unless
we return a null SDValue.

I tried to test this by copying an AArch64 test for ScalarizeVecOp_FP_ROUND.
While it did hit the assert and this commited fixed that. It also
hit a later problem that couldn't be fixed without adding strict
FP support to AArch64.

diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp
index 11f6688..dce2867 100644 (file)
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp
@@ -777,7 +777,13 @@ SDValue DAGTypeLegalizer::ScalarizeVecOp_STRICT_FP_ROUND(SDNode *N,
   // Legalize the chain result - switch anything that used the old chain to
   // use the new one.
   ReplaceValueWith(SDValue(N, 1), Res.getValue(1));
-  return DAG.getNode(ISD::SCALAR_TO_VECTOR, SDLoc(N), N->getValueType(0), Res);
+
+  Res = DAG.getNode(ISD::SCALAR_TO_VECTOR, SDLoc(N), N->getValueType(0), Res);
+
+  // Do our own replacement and return SDValue() to tell the caller that we
+  // handled all replacements since caller can only handle a single result.
+  ReplaceValueWith(SDValue(N, 0), Res);
+  return SDValue();
 } 
 
 SDValue DAGTypeLegalizer::ScalarizeVecOp_VECREDUCE(SDNode *N) {