[PATCH] D31186: Changing TargetTransformInfo::getGEPCost to take GetElementPtrInst as parameter

[Hal Finkel via Phabricator via llvm-commits]

hfinkel added a comment.

In https://reviews.llvm.org/D31186#708507, @jonpa wrote:

> >   User stories:
> >   
> >   An user wants to estimate the cost of an operation to make a decision whether it's worth to create it. The operation does not exist in IR.
> >   An user has an operation in IR and wants to know the cost of the operation to estimate its contribution into execution.
>
> I think there is also the case in a vectorizer, where there is an existing instruction but the cost query is for the same instruction *vectorized* with VF.
>
> > Jonas, an optional parameter duplicates the information passed through other parameters. It can provide all of the needed information. Also single API for all use cases might create some kind of misunderstanding.
>
> No, not in the case in the vectorizer. Here the scalar instruction is passed, with vector types.


But that is that the vectorizer normally does. It takes the scalar instruction and emits the same instruction with vector types. You need to explain how any other case is different.


https://reviews.llvm.org/D31186