llvm-project

ef7e03a2 - [VPlan] Limit ExtractLastElem fold to recipes guaranteed single-scalar.

[VPlan] Limit ExtractLastElem fold to recipes guaranteed single-scalar. vputils::isSingleScalar(A) may return true to recipes that produce only a single scalar value, but they could still end up as vector instruction, because the recipe could not be converted to a single-scalar VPInstruction/VPReplicateRecipe. For now, only apply the fold for recipes guaranteed to produce a single value, i.e. single-scalar VPInstructions and VPReplicateRecipes. Fixes https://github.com/llvm/llvm-project/issues/158319.