[llvm] [InstCombine] Fold `fcmp (fmul X, C1), C2` to `fcmp X, C2/C1` (PR #205003)

[via llvm-commits]

VachanVY wrote:

> @arsenm Could you please advise me on how to proceed with the hazard around underflow as you mentioned?

@arsenm I've removed the denormal check as you said, please guide me on how to proceed with the underflow hazard you mentioned.

https://github.com/llvm/llvm-project/pull/205003