9d60e95bcd
Return poison instead of undef for non-demanded lanes in the AMDGPU demanded element simplification hook. Also bail out of dmask is 0, as this case has special semantics: > If DMASK==0, the TA overrides DMASK=1 and puts zeros in VGPR followed by > LWE status if exists. TFE status is not generated since the fetch is dropped.