[PATCH] D115052: [Passes] Only run extra vector passes if loops have been vectorized.

Fri Dec 3 13:33:41 PST 2021

fhahn added a comment.

In D115052#3170517 <https://reviews.llvm.org/D115052#3170517>, @lebedev.ri wrote:

> It would be good to mimic what the module equivalence check does
> (when no changes were reported, the module should not have been changed),
> and e.g. when in EXPENSIVE_CHECKS mode, if we weren't going to run those
> extra vectorization passes because we predicted they wouldn't do anything,
> to still run them, and check that they actually didn't do anything.

Unfortunately I don't think this will be feasible. The extra passes may simplify things in functions where nothing gets vectorized, *but* I think this is only a side-effect of the current implementation. The comment for the extra passes states that they are specifically intended to simplify runtime checks generated by the vectorizer.

Repository:
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  https://reviews.llvm.org/D115052/new/

https://reviews.llvm.org/D115052