[llvm] [RFC][LV] VPlan-based cost model (PR #67647)

[Florian Hahn via llvm-commits]

fhahn wrote:

> Is there a list of benchmarks we should care about for the community ? Spec2k6, tsvc ? To me to enable vplan-based cost model in one shot is not a trivial work, not only because of benchmarks, but also because of multiple targets. We can enable it by targets only and take a responsibility to do that for RISC-V first.

After my recent update to https://github.com/llvm/llvm-project/pull/67934, I think we should be able to gradually migrate to the VPlan-based cost-model on a per-recipe basis, starting with `VPWidenRecipe`. Other recipes can be converted gradually, reducing the potential number of regressions.

 As I mentioned earlier, with #67934 , the chosen VFs agree with the legacy cost model for a large test set (llvm-test-suite (includes tsvc and many others) , SPEC2017, clang bootstrap, some large internal projects on multiple platforms and configs, more details in my previous comment https://github.com/llvm/llvm-project/pull/67647#issuecomment-2081474460). There's no pre-defined set of test suites I think, but the ones I mentioned should cover a lot of ground.


https://github.com/llvm/llvm-project/pull/67647