[SDAG] Don't try to use FP_EXTEND/FP_ROUND for int<->fp promotions

The PowerPC backend has long promoted some floating-point vector operations
(such as select) to integer vector operations. Unfortunately, this behavior was
broken by r216555. When using FP_EXTEND/FP_ROUND for promotions, we must check
that both the old and new types are floating-point types. Otherwise, we must
use BITCAST as we did prior to r216555 for everything.

llvm-svn: 228969

1 files changed, 5 insertions, 3 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp
index 11e6b38f076..3a8c276e261 100644
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp
@@ -390,7 +390,8 @@ SDValue VectorLegalizer::Promote(SDValue Op) {
       if (Op.getOperand(j)
               .getValueType()
               .getVectorElementType()
-              .isFloatingPoint())
+              .isFloatingPoint() &&
+          NVT.isVector() && NVT.getVectorElementType().isFloatingPoint())
         Operands[j] = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Op.getOperand(j));
       else
         Operands[j] = DAG.getNode(ISD::BITCAST, dl, NVT, Op.getOperand(j));
@@ -399,8 +400,9 @@ SDValue VectorLegalizer::Promote(SDValue Op) {
   }
 
   Op = DAG.getNode(Op.getOpcode(), dl, NVT, Operands);
-  if (VT.isFloatingPoint() ||
-      (VT.isVector() && VT.getVectorElementType().isFloatingPoint()))
+  if ((VT.isFloatingPoint() && NVT.isFloatingPoint()) ||
+      (VT.isVector() && VT.getVectorElementType().isFloatingPoint() &&
+       NVT.isVector() && NVT.getVectorElementType().isFloatingPoint()))
     return DAG.getNode(ISD::FP_ROUND, dl, VT, Op, DAG.getIntPtrConstant(0));
   else
     return DAG.getNode(ISD::BITCAST, dl, VT, Op);