Address review comments

Co-authored-by: Alexey Bataev <[email protected]>

Author: preames

llvm/lib/Analysis/VectorUtils.cpp

@@ -415,23 +415,23 @@ bool llvm::getShuffleDemandedElts(int SrcWidth, ArrayRef<int> Mask,
 
 bool llvm::isMaskedSlidePair(ArrayRef<int> Mask, int NumElts,
                              std::pair<int, int> SrcInfo[2]) {
-  int SignalValue = NumElts * 2;
+  const int SignalValue = NumElts * 2;
   SrcInfo[0] = {-1, SignalValue};
   SrcInfo[1] = {-1, SignalValue};
-  for (unsigned i = 0; i != Mask.size(); ++i) {
-    int M = Mask[i];
+  for (auto [i, M] : enumerate(Mask)) {
     if (M < 0)
       continue;
     int Src = M >= (int)NumElts;
     int Diff = (int)i - (M % NumElts);
     bool Match = false;
     for (int j = 0; j < 2; j++) {
-      if (SrcInfo[j].first == -1) {
-        assert(SrcInfo[j].second == SignalValue);
-        SrcInfo[j].first = Src;
-        SrcInfo[j].second = Diff;
+      auto &[SrcE, DiffE] = SrcInfo[j];
+      if (SrcE == -1) {
+        assert(DiffE == SignalValue);
+        SrcE = Src;
+        DiffE = Diff;
       }
-      if (SrcInfo[j].first == Src && SrcInfo[j].second == Diff) {
+      if (SrcE == Src && DiffE == Diff) {
         Match = true;
         break;
       }

llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp

@@ -494,9 +494,10 @@ InstructionCost RISCVTTIImpl::getSlideCost(FixedVectorType *Tp,
 
   auto getSlideOpcode = [&](int SlideAmt) {
     assert(SlideAmt != 0);
+    bool IsVI = isUInt<5>(std::abs(SlideAmt));
     if (SlideAmt < 0)
-      return SlideAmt > -32 ? RISCV::VSLIDEDOWN_VI : RISCV::VSLIDEDOWN_VX;
-    return SlideAmt < 32 ? RISCV::VSLIDEUP_VI : RISCV::VSLIDEUP_VX;
+      return IsVI ? RISCV::VSLIDEDOWN_VI : RISCV::VSLIDEDOWN_VX;
+    return IsVI ? RISCV::VSLIDEUP_VI : RISCV::VSLIDEUP_VX;
   };
 
   std::pair<int, int> SrcInfo[2];