Since the divergence-driven ISel was fully enabled we have more VGPRs available.
MachineScheduler trying to take advantage of that bumps up the occupancy sacrificing the hiding of memory access latency. This really spoils the initially good schedule. A new metric that reflects the latency hiding quality of the schedule has been created to make it to balance between occupancy and latency. The metric is based on the latency model which computes the bubble to working cycles ratio. Then we use this ratio to decide if the higher occupancy schedule is profitable as follows: Profit = NewOccupancy/OldOccupancy * OldMetric/NewMetric
You do not seem to need it here.