[PATCH] D61419: Support FNeg constant folding

Thu May 2 10:23:22 PDT 2019

cameron.mcinally added a comment.

In D61419#1488170 <https://reviews.llvm.org/D61419#1488170>, @cameron.mcinally wrote:

> Couple of updates...
>
> In D61419#1487929 <https://reviews.llvm.org/D61419#1487929>, @cameron.mcinally wrote:
>
> > In D61419#1487834 <https://reviews.llvm.org/D61419#1487834>, @spatel wrote:
> >
> > > Let me know if I'm not seeing it correctly, but the DAG change is independent of the IR changes, so it should be a stand-alone patch.
> >
> >
> > Yes, you're correct. Kind of... I noticed that FNeg wasn't folding vectors with some undef elements correctly while working on this change. I can separate that patch if you'd like.
>
>
> This actually can't be separated out. We were mistakenly generating an FSub, instead of an FNeg in the IRBuilder, so the DAG code won't trigger without the IRBuilder change. I won't be able to write a test for it without that change (at least that I know about right now) .

Oh, I suppose I could let the DAG change sit until after the IRBuilder change lands also.

Repository:
  rL LLVM

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  https://reviews.llvm.org/D61419/new/

https://reviews.llvm.org/D61419