[X86] isTargetShuffleEquivalent - merge duplicate array accesses. NFCI.

Author: RKSimon

llvm/lib/Target/X86/X86ISelLowering.cpp

@@ -10955,7 +10955,7 @@ static bool isTargetShuffleEquivalent(MVT VT, ArrayRef<int> Mask,
     int ExpectedIdx = ExpectedMask[i];
     if (MaskIdx == SM_SentinelUndef || MaskIdx == ExpectedIdx)
       continue;
-    if (0 <= Mask[i] && 0 <= ExpectedMask[i]) {
+    if (0 <= MaskIdx && 0 <= ExpectedIdx) {
       SDValue MaskV = MaskIdx < Size ? V1 : V2;
       SDValue ExpectedV = ExpectedIdx < Size ? V1 : V2;
       MaskIdx = MaskIdx < Size ? MaskIdx : (MaskIdx - Size);