================
Comment at: lib/CodeGen/TargetInfo.cpp:1634-1635
@@ -1630,3 +1633,4 @@
unsigned getOpenMPSimdDefaultAlignment(QualType) const override {
+ // FIXME: What about AVX512?
return getABIInfo().hasAVX() ? 32 : 16;
}
----------------
ABataev wrote:
> rjmccall wrote:
> > ab wrote:
> > > This I'm not sure; it makes sense to me to align to 64 when we have
> > > AVX512.
> > >
> > > There's also the WinX86_64 counterpart, which I'm even less confident
> > > about.
> > I am pretty skeptical of even the original code here, frankly. Are clients
> > really making stronger promises just because they're compiling with AVX
> > enabled? Note that the compiler doesn't *do* anything to achieve this; it
> > literally just makes a more aggressive assumption about what the user has
> > done.
> >
> > It seems to me like the (1) the OpenMP people ought to review this and
> > seriously consider it and (2) this number needs to be available to code in
> > some portable manner, probably via a predefined macro. Which means it
> > probably ought to be defined in the AST-level TargetInfo. CC'ing Alexey
> > Bataev.
> John, here is an excerpt from the OpenMP "If no optional parameter is
> specified, implementation-defined default
> alignments for SIMD instructions on the target platforms are assumed." So,
> the value can be chosen by the compiler. But I think it is a good idea to
> have a macro for this.
Okay. Would you mind making sure that happens? In the meantime, I think we
should bump the alignment up to 64 here when AVX512 is enabled.
http://reviews.llvm.org/D9894
EMAIL PREFERENCES
http://reviews.llvm.org/settings/panel/emailpreferences/
_______________________________________________
cfe-commits mailing list
[email protected]
http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
