[PATCH] D44338: [LV][VPlan] Build plain CFG with simple recipes for outer loops.

[Diego Caballero via Phabricator via llvm-commits]

dcaballe added inline comments.


================
Comment at: lib/Transforms/Vectorize/LoopVectorize.cpp:7704
+    if (VPlanBuildStressTest)
+      return {UserVF, 0};
+
----------------
fhahn wrote:
> Could we here just return NoVectorization and get rid of the additional check in LoopVectorizePass::processLoop? Also, could we move the setting of UserVF in `plan` too? Otherwise it seems harder to keep track of what's going on and we set UserVF even for inner loops.
> 
> Also, I think ideally we would only bail out if the outer loop is not supported, but achieving that seems more trouble than it's worth.
> Could we here just return NoVectorization and get rid of the additional check in LoopVectorizePass::processLoop?

Ok. It sounds good to me, at least for now. Hopefully we won't introduce anything after `plan` that we must skip in stress testing mode. Thanks!

> Also, could we move the setting of UserVF in plan too? Otherwise it seems harder to keep track of what's going on and we set UserVF even for inner loops.

Could you please elaborate a bit more? I'm not sure I understand what you mean.

> Also, I think ideally we would only bail out if the outer loop is not supported, but achieving that seems more trouble than it's worth.

We can think about it in the future. We would need legality analysis for outer loops if we want to generate code.


Repository:
  rL LLVM

https://reviews.llvm.org/D44338