!fixup address latest comments, thanks!

Author: fhahn

llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp

@@ -12322,14 +12322,15 @@ void SelectionDAGBuilder::lowerWorkItem(SwitchWorkListItem W, Value *Cond,
       case CC_Range: {
         const Value *RHS, *LHS, *MHS;
         ISD::CondCode CC;
-        if (I->Low == I->High || I->Kind == CC_And) {
+        if (I->Low == I->High) {
           // Check Cond == I->Low.
           CC = ISD::SETEQ;
           LHS = Cond;
           RHS=I->Low;
           MHS = nullptr;
         } else {
           // Check I->Low <= Cond <= I->High.
+          assert(I->Kind != CC_And && "CC_And must be handled above");
           CC = ISD::SETLE;
           LHS = I->Low;
           MHS = Cond;

llvm/lib/CodeGen/SwitchLoweringUtils.cpp

@@ -365,7 +365,7 @@ void SwitchCG::SwitchLowering::findBitTestClusters(CaseClusterVector &Clusters,
 
   // Check if the clusters contain one checking for 0 and another one checking
   // for a power-of-2 constant with matching destinations. Those clusters can be
-  // combined to a single ane with CC_And.
+  // combined to a single one with CC_And.
   unsigned ZeroIdx = -1;
   for (const auto &[Idx, C] : enumerate(Clusters)) {
     if (C.Kind != CC_Range || C.Low != C.High)
@@ -391,7 +391,7 @@ void SwitchCG::SwitchLowering::findBitTestClusters(CaseClusterVector &Clusters,
     return;
 
   APInt Pow2 = Clusters[Pow2Idx].Low->getValue();
-  APInt NewC = (Pow2 + 1) * -1;
+  APInt NewC = ~Pow2;
   Clusters[ZeroIdx].Low = ConstantInt::get(SI->getContext(), NewC);
   Clusters[ZeroIdx].High = ConstantInt::get(SI->getContext(), NewC);
   Clusters[ZeroIdx].Kind = CC_And;