[llvm] [LV] Make ScalarEpilogue a LoopVectorizeHint (PR #160125)

[Luke Lau via llvm-commits]

lukel97 wrote:

> > > as it is really a kind of hint that's dependent on the user's preferences
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> > Aren't loop hints for loop pragmas etc? I don't think the user can control whether or not a scalar epilogue is emitted on a loop by loop basis. `-prefer-predicate-over-epilogue` is more of a TTI override
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> Hm, by that reasoning isn't ForceScalableVectorization, which is also a hint, also a TTI override?

The TTI only controls the default.  ForceScalableVectorization comes from `#pragma clang loop vectorize_width(4, scalable)` IIRC.


https://github.com/llvm/llvm-project/pull/160125