[llvm] [SLP][REVEC] Support more mask pattern usage in shufflevector. (PR #106212)

[Alexey Bataev via llvm-commits]

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@@ -309,7 +308,7 @@ static unsigned getShufflevectorNumGroups(ArrayRef<Value *> VL) {
     auto *SV = cast<ShuffleVectorInst>(VL[I]);
     Value *Src = SV->getOperand(0);
     ArrayRef<Value *> Group = VL.slice(I, GroupSize);
-    SmallVector<int> ExtractionIndex(SVNumElements);
+    SmallBitVector UsedIndex(SVNumElements);
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alexey-bataev wrote:

You don't need to account all elements here, just group indices should be enough, no?

https://github.com/llvm/llvm-project/pull/106212