[llvm] [SLP][REVEC] Initial commits. (PR #98269)

[Alexey Bataev via llvm-commits]

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@@ -227,15 +231,26 @@ static const unsigned MaxPHINumOperands = 128;
 /// avoids spending time checking the cost model and realizing that they will
 /// be inevitably scalarized.
 static bool isValidElementType(Type *Ty) {
+  if (RunSLPReVectorization && isa<FixedVectorType>(Ty))
+    Ty = Ty->getScalarType();
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alexey-bataev wrote:

Do you need the check here? Better just use Ty->getScalarTy() directly here and check for RunSLPReVectorization only where the vectorization is requested

https://github.com/llvm/llvm-project/pull/98269