[PATCH] D126774: [InstCombine] Use +0.0 instead of -0.0 as the FP identity for some folds

[David Sherwood via Phabricator via llvm-commits]

david-arm added a comment.

In D126774#3553210 <https://reviews.llvm.org/D126774#3553210>, @dmgreen wrote:

> The Arm backend has patterns to turn the awkward `fadd(select(.., -0.0))` back into a more natural predicated fadd. They will need to be made to work with both the forms, if this is changing.

That's a good point, although it's a shame that there isn't a single test in CodeGen/ARM that defends the DAG combine in `PerformFAddVSelectCombine`. So I'm not entirely sure what DAG combine I need for the IR cases that you're worried about. :(


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