[PATCH] D81368: [SVE] Disable Global and Fast ISel at -O0 if the SVE feature is found

[Amara Emerson via Phabricator via llvm-commits]

aemerson added a comment.

In D81368#2079185 <https://reviews.llvm.org/D81368#2079185>, @david-arm wrote:

> Hi @aemerson, do you know if there are any plans to add scalable vector support to global isel for AArch64?


Hi Greg. I don't have plans personally to work on scalable vector support for GlobalISel, but it's a good idea for someone to do so. Bailing out of both fastisel and GISel will result in SDag being used and hit -O0 compile times significantly.

Maybe a better way would be to fall back to SelectionDAG if any scalable types are found in the IR during translation. A custom "target wants to fall back" hook might be wanted here to make it cleaner. That way, `-fsve` or whatever it is to enable SVE won't unnecessarily use SelectionDAG at -O0 unless there are actual scalable types present.


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https://reviews.llvm.org/D81368