[PATCH] D90445: [SLP] Make SLPVectorizer to use `llvm.masked.gather` intrinsic

Mon Nov 23 11:02:31 PST 2020

fhahn added a comment.

In D90445#2411663 <https://reviews.llvm.org/D90445#2411663>, @anton-afanasyev wrote:

> I believe this issue is related to the default cost for `getGatherScatterOpCost()`. For the arch not having `gather/scatter` instrs we use `TargetTransformInfoImplBase::getGatherScatterOpCost()` which returns 1 unconditionally: https://github.com/llvm/llvm-project/blob/release/11.x/llvm/include/llvm/Analysis/TargetTransformInfoImpl.h#L480
> I'd fix it by setting something like `1024` for the default cost.

yes, I managed to track it down to that. I pushed some additional tests and D91984 <https://reviews.llvm.org/D91984> to add a more realistic estimate for the cost when scalarizing.

Repository:
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https://reviews.llvm.org/D90445