[llvm] [GlobalISel][AArch64][AMDGPU] Lower FPOWI into series of multiplication (PR #95217)

[Matt Arsenault via llvm-commits]

arsenm wrote:

> SelectionDAG already converts FPOWI into multiplications, this patch introduces the same optimization into GlobalISel.

Where do you see this optimization? I'm pretty sure this is not a viable lowering strategy. It would require some set of unsafe math flags, and should go into a combiner, not the legalizer

https://github.com/llvm/llvm-project/pull/95217