[PATCH] D113209: [LV] Use VScaleForTuning to fine-tune the cost per lane.

[Sander de Smalen via Phabricator via llvm-commits]

sdesmalen added a comment.

In D113209#3111176 <https://reviews.llvm.org/D113209#3111176>, @frasercrmck wrote:

> How does this interact with `vscale_range`? Could it perhaps automatically infer `getVScaleForTuning` using that? Or is the idea the target ultimately chooses?

The two are actually quite different; `vscale_range` specifies the range of vscale that the compiled binary is compatible with. LLVM guarantees that the compiled binary is correct for that vscale_range. `VScaleForTuning` can be set separately by `mcpu/mtune` and will purely tune the cost-model without changing the requirements on vscale. This means it doesn't change the compatibility of the binary, it just helps choose a better VF for the CPU it compiles for.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D113209/new/

https://reviews.llvm.org/D113209