From: Yaron K. <yar...@gm...> - 2014-08-12 16:25:39
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Hi Karl I responded on the github issue page, Yaron 2014-08-12 19:12 GMT+03:00 Karl Rupp <ru...@iu...>: > Hi Yaron, > > > > I am trying to use ViennaCL with Ceemple and encountered a possible bug. > >> >> In amg_base.hpp:1045, iter2 is decremented (code below). However, >> nothing (at least locally in this function) prevents iter2 from >> being pointlist.begin() and then the result is undefined, see >> >> http://stackoverflow.com/questions/18225651/is-stdvectorbegin-1-undefined >> >> Also, why are both iter and iter2 required? it seems iter alone could do >> the job. >> > > thanks for reporting. From what I can tell, you are totally right. > Unfortunately, the student who contributed this code moved to the private > sector and is no longer available, so I can't tell whether there are any > invisible guarantees on the set. > > The AMG code is subject to significant refactoring, I added your message > to the associated issue: > https://github.com/viennacl/viennacl-dev/issues/16 > > Do you happen to have a test case where this particular piece of code > triggers an error? A simple fix would indeed be to just remove the use of > iter2, which is probably not a significant performance hit anyway. > > Thanks again and best regards, > Karli > > |