[llvm] [LoopVectorize] Check for vector-to-scalar casts in legalizer (PR #106244)

[via llvm-commits]

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@@ -943,9 +943,12 @@ bool LoopVectorizationLegality::canVectorizeInstrs() {
         VecCallVariantsFound = true;
 
       // Check that the instruction return type is vectorizable.
+      // We can't vectorize casts from vector type to scalar type.
       // Also, we can't vectorize extractelement instructions.
       if ((!VectorType::isValidElementType(I.getType()) &&
            !I.getType()->isVoidTy()) ||
+          (isa<CastInst>(&I) &&
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ErikHogeman wrote:

Thanks, will fix.

https://github.com/llvm/llvm-project/pull/106244