[PATCH] D76124: [TTI] Remove getOperationCost

Wed Mar 18 08:42:11 PDT 2020

spatel added a comment.

In D76124#1929051 <https://reviews.llvm.org/D76124#1929051>, @lebedev.ri wrote:

> Sanity check: i believe, as per `llvm::TargetTransformInfo::getInstructionCost()`,
>  there are three cost-models:
>
> - throughput model (`getInstructionThroughput()`)
> - latency model (`getInstructionLatency()`)
> - size model (`getUserCost()`)
>
>   I'm not sure what `getOperationCost()` is supposed to represent, so i'm not sure how it's code should be redistributed should it be deleted.

It's likely that nobody knows at this point. Anything we can do to clean up and simplify these classes is welcome, but it probably requires cleaning up the user classes too because they've come to expect different meanings for these various vaguely/wrongly named APIs. Example in R43591:
https://bugs.llvm.org/show_bug.cgi?id=43591

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D76124/new/

https://reviews.llvm.org/D76124