http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55051
--- Comment #29 from Jan Hubicka <hubicka at ucw dot cz> 2012-11-16 18:57:41 UTC --- > > I'm confused - that is essentially what it is doing today (although > comparing against the first merged file instead of the last merged > file). It isn't expecting all the gcda files to have the same number > of runs, but when they do it expects them to have the same sum_all. > See the trace of updates I show below this pseudo code in the same > email that shows why that is not working. Hmm, after some tought I guess what can happen is that number of run matches but these are different run, because more than 2 streamings may be running... Honza