------- Additional Comments From rakdver at atrey dot karlin dot mff dot cuni dot cz 2005-05-24 14:24 ------- Subject: Re: poisoned ggc memory used for -ftree-vectorize
> > Is there a rule that ggc_collect should not be called during loop > optimizations? > > I don't know. (Zdenek?) there are several places in loop opts that are not GGC-safe (in particular the tree nodes refered from loop structures are not seen by garbage collector, and I think there are some other instances). So at the moment, you cannot run ggc_collect inside loop opts. > I think passes within the loop optimizer can assume that the scev information > cached in the scev htab can be safely used. During vectorization analysis > some > new entries in the scev htab are initialized, and these are valid to be used > by > subsequent passes. If no transformation takes place during vectorization then > there's no need to invalidate this information. So I don't think we're > missing > a call to scev_reset in the vectorizer. > > The problem is more likely around the fact that ggc_collect, for some reason > seems to free up data that is still pointed to from scalar_evolution_info. > > > > If you have some time to spare, use a --enable-checking=gcac compiler, > and the failure will likely happen much earlier. > > thanks for the tip > > > > You have to make sure that ... the contents of > the scalar evolution hash table are reached during garbage collection. > > any (other) hints on how to do that? > > (by the way, I actually found a few places where don't properly free up > information in the vectorizer, but fixing those didn't solve this particular > problem). > > -- > What |Removed |Added > ---------------------------------------------------------------------------- > CC| |rakdver at atrey dot karlin > | |dot mff dot cuni dot cz > > > http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21639 > > ------- You are receiving this mail because: ------- > You are on the CC list for the bug, or are watching someone who is. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21639
