[llvm] [GlobalISel] Handle div-by-pow2 (PR #83155)

[Thorsten Schütt via llvm-commits]

tschuett wrote:

AArch64 runs the combiner before and after legalization. Most combiner tests are mir files before legalization. I was hit by this file recently:
https://github.com/llvm/llvm-project/blob/main/llvm/test/CodeGen/AArch64/GlobalISel/prelegalizer-combiner-addo-zero.mir
It runs the combiner prelegalization and selects exactly one combine. 

https://github.com/llvm/llvm-project/pull/83155