[PATCH] D92083: [PowerPC] Lower the SETCC/SELECT_CC/BR_CC as libcall for fp128 with Power9 vector disabled

[Qing Shan Zhang via Phabricator via llvm-commits]

steven.zhang added a comment.

In D92083#2504734 <https://reviews.llvm.org/D92083#2504734>, @nemanjai wrote:

> The description isn't really adequate - it does not answer my question at all really. The question is why not set the legalization action for `BR_CC` as `Expand`? Namely, what does the legalizer do that we don't want it to do if we let it expand the node? You just answered the question with the equivalent of "The legalizer does its job and that's not what we want." So please explain why that is not what we want.

Hmm, we will hit assertion with legalizer as it tries to swap the operand and cc to see if target support it, and assertion otherwise. Basicly, we have two options. One is to enhance the legalizer and another one is to do it inside PowerPC target as what this patch did. I am swing between them. Thank you for bringing this up and I have updated the patch to go with direction on enhancing the legalizer.


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  https://reviews.llvm.org/D92083/new/

https://reviews.llvm.org/D92083