Hi, I have noticed that stores get issued to the memory system during
the execute stage, which means they might be issued to the memory out
of order.
However, stores dont really perform and act as prefetches to RUBY ( or
any other memory model) which means upon a branch mispredict rolling
back a store will have no correctness consequences on the memory
system .
However, are we not polluting the cache unnecessarily due to this ?
If the frequency of branch mispredicts is high, I am concerned about
the timing fidelity of Opal with respect to the caches. ( Since
excessive stores may change the timing of subsequent loads)
I have noticed in the SIMICS MAI that stores get issued only during
the retire phase at which point they are guaranteed to be correct thus
avoiding the possibility of a rollback.
Am I correct on all of this ?
I just wanted to confirm my analysis before moving ahead with Opal
thanks
smp
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