[PATCH] D91053: [PowerPC] Lump the constants to save one addis for each constant access

Thu Jul 29 08:49:18 PDT 2021

shchenz added a comment.

In D91053#2912214 <https://reviews.llvm.org/D91053#2912214>, @qiucf wrote:

> In D91053#2912191 <https://reviews.llvm.org/D91053#2912191>, @lkail wrote:
>
>> A few months ago, steven shared his patch to us. For me, it should be an optimization of TOC layout, it looks odd to me to get it done at isel phase. I think we should figure out a new approach for this. What do you think @nemanjai @qiucf ?
>>
>> I tend to not pursue this patch and might have a new one to get TOC layout optimization done.
>
> I think it's located at DAG because we lower such constant pools stuff there. If this can be target independent (as Eli commented in previous patch) in DAG, or put it after ISel (I guess you mean that?), it's fine to abandon that.

I don't think after ISEL is a good idea. After ISel, the constant pool and the code pattern to access the constant pool are both settled down. It does not make sense to me to revert or change them later. It is better to generate it like we expect in the first place.

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