[DAG] SimplifyMultipleUseDemandedBits - early-out for any scalable vector types

Noticed while working to remove SelectionDAG::GetDemandedBits - we were relying on the callers to have already bailed for scalable vectors

diff --git a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index cd4f0ae..6205e74 100644 (file)
--- a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -654,6 +654,14 @@ bool TargetLowering::SimplifyDemandedBits(SDValue Op, const APInt &DemandedBits,
 SDValue TargetLowering::SimplifyMultipleUseDemandedBits(
     SDValue Op, const APInt &DemandedBits, const APInt &DemandedElts,
     SelectionDAG &DAG, unsigned Depth) const {
+  EVT VT = Op.getValueType();
+
+  // Pretend we don't know anything about scalable vectors for now.
+  // TODO: We can probably do more work on simplifying the operations for
+  // scalable vectors, but for now we just bail out.
+  if (VT.isScalableVector())
+    return SDValue();
+
   // Limit search depth.
   if (Depth >= SelectionDAG::MaxRecursionDepth)
     return SDValue();
@@ -664,7 +672,7 @@ SDValue TargetLowering::SimplifyMultipleUseDemandedBits(
 
   // Not demanding any bits/elts from Op.
   if (DemandedBits == 0 || DemandedElts == 0)
-    return DAG.getUNDEF(Op.getValueType());
+    return DAG.getUNDEF(VT);
 
   bool IsLE = DAG.getDataLayout().isLittleEndian();
   unsigned NumElts = DemandedElts.getBitWidth();
@@ -894,6 +902,13 @@ SDValue TargetLowering::SimplifyMultipleUseDemandedBits(
     SDValue Op, const APInt &DemandedBits, SelectionDAG &DAG,
     unsigned Depth) const {
   EVT VT = Op.getValueType();
+
+  // Pretend we don't know anything about scalable vectors for now.
+  // TODO: We can probably do more work on simplifying the operations for
+  // scalable vectors, but for now we just bail out.
+  if (VT.isScalableVector())
+    return SDValue();
+
   APInt DemandedElts = VT.isVector()
                            ? APInt::getAllOnes(VT.getVectorNumElements())
                            : APInt(1, 1);