message from a known peer (not MPI_ANY_SOURCE) then we can attach the
remote proc and initialize the convertor as soon as we know the data-type,
and the count (so basically in the _INIT macro). If it's not the case, then
create them in the _MATCHED macro (as in the original version). Of course,
beforeinitializing the convertor we check that there will be some data
in the message.
This commit, plus the convertor improvements from few days ago, lower the
latency for my test case environment (mvapi) by 0.1 microseconds. The convertor
now is as slim as it can be, I don't think there is anything else to
remove/improve.
This commit was SVN r9843.
e658557d52