http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55051
--- Comment #25 from Teresa Johnson <tejohnson at google dot com> 2012-11-15 14:34:10 UTC --- On Thu, Nov 15, 2012 at 2:56 AM, hubicka at ucw dot cz < gcc-bugzi...@gcc.gnu.org> wrote: > > http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55051 > > --- Comment #24 from Jan Hubicka <hubicka at ucw dot cz> 2012-11-15 > 10:56:53 UTC --- > > Note though that this is not an assert. It just emits a message to > > stderr. Do you think a better error message is appropriate? I'm not > > sure the "some data files may have been removed" is an accurate > > description of the issue. Perhaps something like "Profile data file > > mismatch may indicate corrupt profile data"? > > Well, we should figure out why sum_all starts to diverge. If we had > problems mixing cc1 and cc1plus executions, we should get mismatches in > number of counters. Right, it doesn't appear to be different executables since the number of counters is identical. I'll instrument it and see if I can figure out why they diverge. > What happens after the miscompare? > A flag is set so that the error is emitted at most once per merge, and then we continue on with the merge and ignore it. Basically what it is doing is saving the first merged summary (for the first object file's gcda we merge into), and then for each additional object file that gets its counters merged the resulting program summary is compared against the saved program summary. But only if the number of runs is the same as the saved summary. This could happen if the gcda files are walked in a different order during updates (i.e. the gcov_list is in a different order for different processes of the same executable), but I am not sure if that can happen. Teresa > Honza > > -- > Configure bugmail: http://gcc.gnu.org/bugzilla/userprefs.cgi?tab=email > ------- You are receiving this mail because: ------- > You are on the CC list for the bug. >
