SimplifyDemandedBits - Remove duplicate getOperand() call. NFC.

Pulled out from D56387 - cleanup variable names, move shift amount legalization inside if() of its only user and remove duplicate getOperand() call.

diff --git a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index 022efc6..155d68c 100644 (file)
--- a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -1769,15 +1769,11 @@ bool TargetLowering::SimplifyDemandedBits(
           // undesirable.
           break;
 
-        auto *ShAmt = dyn_cast<ConstantSDNode>(Src.getOperand(1));
-        if (!ShAmt || ShAmt->getAPIntValue().uge(BitWidth))
+        SDValue ShAmt = Src.getOperand(1);
+        auto *ShAmtC = dyn_cast<ConstantSDNode>(ShAmt);
+        if (!ShAmtC || ShAmtC->getAPIntValue().uge(BitWidth))
           break;
-
-        SDValue Shift = Src.getOperand(1);
-        uint64_t ShVal = ShAmt->getZExtValue();
-
-        if (TLO.LegalTypes())
-          Shift = TLO.DAG.getConstant(ShVal, dl, getShiftAmountTy(VT, DL));
+        uint64_t ShVal = ShAmtC->getZExtValue();
 
         APInt HighBits =
             APInt::getHighBitsSet(OperandBitWidth, OperandBitWidth - BitWidth);
@@ -1787,10 +1783,12 @@ bool TargetLowering::SimplifyDemandedBits(
         if (!(HighBits & DemandedBits)) {
           // None of the shifted in bits are needed.  Add a truncate of the
           // shift input, then shift it.
+          if (TLO.LegalTypes())
+            ShAmt = TLO.DAG.getConstant(ShVal, dl, getShiftAmountTy(VT, DL));
           SDValue NewTrunc =
               TLO.DAG.getNode(ISD::TRUNCATE, dl, VT, Src.getOperand(0));
           return TLO.CombineTo(
-              Op, TLO.DAG.getNode(ISD::SRL, dl, VT, NewTrunc, Shift));
+              Op, TLO.DAG.getNode(ISD::SRL, dl, VT, NewTrunc, ShAmt));
         }
         break;
       }