1 files changed, 21 insertions, 0 deletions
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index b355cc9..2c0ed3f 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -4327,6 +4327,27 @@ SDValue DAGCombiner::visitVSELECT(SDNode *N) {
     }
   }
 
+  // Treat SETCC as a mask and promote the result type based on the targets
+  // expected SETCC result type. This will ensure that SETCC and VSELECT are
+  // both split by the type legalizer. This is done to prevent the type
+  // legalizer from unrolling SETCC into scalar comparions.
+  EVT SelectVT = N->getValueType(0);
+  if (N0.getOpcode() == ISD::SETCC &&
+      N0.getValueType() != getSetCCResultType(SelectVT)) {
+    SDLoc MaskDL(N0);
+    EVT MaskVT = getSetCCResultType(SelectVT);
+
+    SDValue Mask = DAG.getNode(ISD::SETCC, MaskDL, MaskVT, N0->getOperand(0),
+                               N0->getOperand(1), N0->getOperand(2));
+
+    AddToWorkList(Mask.getNode());
+
+    SDValue LHS = N->getOperand(1);
+    SDValue RHS = N->getOperand(2);
+
+    return DAG.getNode(ISD::VSELECT, DL, SelectVT, Mask, LHS, RHS);
+  }
+
   return SDValue();
 }