A concurrent instruction dispatch apparatus includes a group indicator for
each of a plurality of threads that indicates which one of a plurality of
groups of the threads the thread belongs to. A group priority indicator
for each group indicates an instruction dispatch priority relative to the
other groups. Selection logic selects a thread for dispatching an
instruction thereof based on the group and group priority indicators. A
bifurcated scheduler includes first scheduler logic that issues
instructions of the threads to an execution unit, second scheduler logic
that enforces a thread scheduling policy, and an interface. A group
indicator indicates which group each thread belongs to, a priority for
each group, and execution information for each thread. The first
scheduler logic issues the instructions based on the group priorities and
group indicators, and the second scheduler logic updates the group
indicators based on the instruction execution information.