1 files changed, 23 insertions, 0 deletions
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 7343236e6a..90cd1d3ee2 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -4364,6 +4364,29 @@ SDValue DAGCombiner::visitVSELECT(SDNode *N) {
     }
   }
 
+  // Treat SETCC as a vector 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);
+  EVT MaskVT = getSetCCResultType(SelectVT);
+  assert(MaskVT.isVector() && "Expected a vector type.");
+  if (N0.getOpcode() == ISD::SETCC && N0.getValueType() != MaskVT) {
+    SDLoc MaskDL(N0);
+
+    // Extend the mask to the desired value type.
+    ISD::NodeType ExtendCode =
+      TargetLowering::getExtendForContent(TLI.getBooleanContents(true));
+    SDValue Mask = DAG.getNode(ExtendCode, MaskDL, MaskVT, N0);
+
+    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();
 }