[llvm] [VectorUtils] Trivially vectorize ldexp, [l]lround (PR #145545)

[Ramkumar Ramachandra via llvm-commits]

artagnon wrote:

> I would expect the costs to be something like 10 for a libcall, and 10*4+scalarization_overhead for the vector. They might need to be overriden on AArch64 as they are marked custom, but I don't see them in BasicTTIImplBase::getTypeBasedIntrinsicInstrCost.

Will investigate.
 
> Can you add tests for SLP / scalarizer, as in https://reviews.llvm.org/D124358 or https://github.com/llvm/llvm-project/pull/71416/files?

Curiously, SLPVectorizer doesn't seem to vectorize [l]lround/ldexp.

https://github.com/llvm/llvm-project/pull/145545