[llvm] [AMDGPU][MachineRegisterInfo] Extend the MRI live-ins check to account for Subreg (PR #126926)

[Vikash Gupta via llvm-commits]

vg0204 wrote:

> On second look, I'm not sure what problem this is supposed to solve. Last I checked, the MachineVerifier did not use the MachineRegisterInfo / MachineFunction liveins for anything. It does not factor into the liveness calculation, or verification. Only the MachineBasicBlock's liveins should matter (where we do have actual bugs in the verifier, especially for the entry block).

Yes, thats true and as you said looking into MBB(entry) live-in should apprently take care of machine verifier spawned in SILowerSgprSpills(). But, if we see from other point of view considering your comments

> However, I still think we should replace all of the livein references to be directly in terms of regunits

Don't we really need this!



https://github.com/llvm/llvm-project/pull/126926