----- Original Message ----- > From: "Nadav Rotem" <[email protected]> > To: "Hal Finkel" <[email protected]> > Cc: "Tyler Nowicki" <[email protected]>, "Alexey Bataev" > <[email protected]>, "llvm cfe" > <[email protected]> > Sent: Tuesday, April 22, 2014 2:26:32 PM > Subject: Re: [PATCH] #pragma vectorize > > > > > On Apr 22, 2014, at 12:07 PM, Hal Finkel < [email protected] > wrote: > > > Hrmm; interesting. Is this the behavior we want? I'd be inclined to > say that the pragma should imply safety. > > > I prefer to implement ‘unsafe’ vectorization with a separate pragma > keyword. I would like to discourage users from using this option > because it can break the correctness of their program, and I think > that ’safe’ is a better default. Vectorizing a loop in an ‘unsafe’ > mode adds a risk and marking the loop with the ‘unsafe’ keyword > makes the decision explicit and documents. > I think that it is reasonable to require users to write: #pragma > vectorize unsafe width(4) …
Okay, I misunderstood. So neither of the proposed pragmas imply safety? For consistency, that's better. I think that, for both, we should have safety-implying variants (or should we use something else entirely for that? ivdep?). FWIW, I don't like 'unsafe', I'd like something closer to 'force' (but I don't like that either because it cannot always be forced). It is really an assertion about iteration independence. But if neither currently imply safety, then the 'unsafe' support can go into a different patch. -Hal > > > Thanks, > Nadav -- Hal Finkel Assistant Computational Scientist Leadership Computing Facility Argonne National Laboratory _______________________________________________ cfe-commits mailing list [email protected] http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
