On Wed, 2017-05-17 at 10:41 +0100, Bin.Cheng wrote: > I happen to be working on loop distribution now (If guess correctly, > to get hmmer fixed). So far my idea is to fuse the finest > distributed > loop in two passes, in the first pass, we merge all SCCs due to > "true" > data dependence; in the second one we identify all SCCs and breaks > them on dependent edges due to possible alias. Breaking SCCs with > minimal edge set can be modeled as Feedback arc set problem which is > NP-hard. Fortunately the problem is small in our case and there are > approximation algorithms. OTOH, we should also improve loop > distribution/fusion to maximize parallelism / minimize > synchronization, as well as maximize data locality, but I think this > is not needed to get hmmer vectorized.
Vectorizing hmmer is what I am interested in so I am glad to hear you are looking into that. You are obviously more knowledgable about the GCC loop infrastructure then I am so I look forward to what you come up with. Steve Ellcey sell...@cavium.com
