[llvm] [SelectionDAG] Avoid one comparison when legalizing fmaximum (PR #142732)

[Nikita Popov via llvm-commits]

nikic wrote:

> > We already know at this point that both values must be +/-0.0
> 
> Isn't it just one of them that must be +/-0.0? We only know that the other value is smaller (max)/bigger (min) than 0.
> 
> > only check the sign of one of the values
> 
> If we were actually checking the sign this would work, but we compare equality with integer 0.

You are right. I've reverted this for now.

https://github.com/llvm/llvm-project/pull/142732