Augmenting the DataBlock class with a change log structure to
record the effects of atomic operations on a data block and
service these changes if the atomic operations require return
values.
Although the operations are atomic, the coalescer need not
send unique memory requests for each operation. Atomic
operations within a wavefront to the same address are now
coalesced into a single memory request. The response of this
request carries all the necessary information to provide the
requesting lanes unique values as a result of their individual
atomic operations. This helps reduce contention for request
and response queues in simulation.
Previously, only the final value of the datablock after all
atomic ops to the same address was visible to the requesting
waves. This change corrects this behavior by allowing each wave
to see the effect of this individual atomic op is a return value
is necessary.
Change-Id: I639bea943afd317e45f8fa3bff7689f6b8df9395
f6a453362f