On Fri, Jul 6, 2012 at 2:31 PM, Chad Rosier <[email protected]> wrote: > > On Jul 6, 2012, at 1:45 PM, Eli Friedman wrote: > >> On Fri, Jul 6, 2012 at 1:14 PM, Chad Rosier <[email protected]> wrote: >>> All, >>> Attached is a patch that enables a per target max vector alignment field >>> (e.g., 32-byte alignment for x86 due to AVX). Currently, if no aligned >>> attribute is specified the alignment of a vector is inferred from its size. >>> Thus, very large vectors will be over-aligned with no benefit. With this >>> patch in place the alignment will be the lesser of the size of the vector >>> and the target max alignment unless an aligned attribute is used. >> >> It doesn't seem likely that x86 itself will go beyond 32-byte vectors, >> but this sort of thing is hard to predict; a few years ago, it wasn't >> obvious that x86 was going to introduce vectors with 32-byte >> alignment. > > Ok. Do you have opinion for or against the patch or were you just making a > general comment?
I'm not entirely sure whether that's an argument for or against this patch, just that we should be careful here; it's not uncommon for architectures to introduce new vector types, and they usually want to be natively aligned. -Eli _______________________________________________ cfe-commits mailing list [email protected] http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
