[X86] combineBT - use SimplifyDemandedBits instead of GetDemandedBits

RKSimon · RKSimon · commit b065902ed458 · 2020-01-21T14:24:46.000Z
Another step towards removing SelectionDAG::GetDemandedBits entirely
diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -43175,14 +43175,13 @@ static SDValue combineAndnp(SDNode *N, SelectionDAG &DAG,
 
 static SDValue combineBT(SDNode *N, SelectionDAG &DAG,
                          TargetLowering::DAGCombinerInfo &DCI) {
-  SDValue N0 = N->getOperand(0);
   SDValue N1 = N->getOperand(1);
 
   // BT ignores high bits in the bit index operand.
   unsigned BitWidth = N1.getValueSizeInBits();
   APInt DemandedMask = APInt::getLowBitsSet(BitWidth, Log2_32(BitWidth));
-  if (SDValue DemandedN1 = DAG.GetDemandedBits(N1, DemandedMask))
-    return DAG.getNode(X86ISD::BT, SDLoc(N), MVT::i32, N0, DemandedN1);
+  if (DAG.getTargetLoweringInfo().SimplifyDemandedBits(N1, DemandedMask, DCI))
+    return SDValue(N, 0);
 
   return SDValue();
 }
