On Tue, 19 Jun 2012, Richard Guenther wrote: > > > Richard Guenther <rguent...@suse.de> writes: > > > We are too eager to bump alignment of some decls when vectorizing. > > > The fix is to not bump alignment of decls the user explicitely > > > aligned or that are used in an unknown way. > > > > I thought attribute((__aligned__)) only set a minimum alignment for > > variables? Most usees I've seen have been trying to get better > > performance from higher alignment, so it might not go down well if the > > attribute stopped the vectoriser from increasing the alignment still > > further. > > That's what the documentation says indeed. I'm not sure which part of > the patch fixes the ObjC failures where the alignment is part of the ABI > (and I suppose ObjC then mis-uses the aligned attribute?).
A quick test shows that if (DECL_PRESERVE_P (decl)) alone is enough to fix the objc failures, while they are still there if one uses only if (DECL_USER_ALIGN (decl)) Dominique
