[llvm-branch-commits] [llvm] ValueTracking: Teach computeKnownFPClass about exp(-inf) (PR #172496)

[Matt Arsenault via llvm-branch-commits]

arsenm wrote:

> > If the source cannot be -inf, the result cannot be +0.
> 
> Surely exp(-999999) would be zero?

Ugh yes. My original version of this depended on a giant patch to do exponent range analysis which I was hoping to avoid needing to resurrect 

https://github.com/llvm/llvm-project/pull/172496