[llvm-branch-commits] [llvm] [AMDGPU] Precommit si-fold-bitmask.mir (PR #131310)

[Matt Arsenault via llvm-branch-commits]

arsenm wrote:

> GlobalISel unfortunately needs it. We can end up with things like a `G_LSHR` with the shift amount being zext'd, and they're both lowered independently so we have a `s_and_b32` of the shift amount.

It should always be post legalize / post regbankselect combinable. Things are strictly more difficult after selection 

https://github.com/llvm/llvm-project/pull/131310