On Sun, Dec 22, 2013 at 12:19:56PM +0100, Uros Bizjak wrote:
> On Fri, Dec 20, 2013 at 5:55 PM, H.J. Lu <hjl.to...@gmail.com> wrote:
> > On Fri, Dec 20, 2013 at 8:47 AM, Ilya Tocar <tocarip.in...@gmail.com> wrote:
> >>> > Perhaps we should add sandybridge, ivybridge and haswell aliases for
> >>> > corei7-avx, core-avx-i, core-avx2? I mean, it is a nightmare to
> >>> > remember
> >>> > which one has the i7 in and which doesn't even for me.
> >>>
> >>> Yes please, I think this is a good idea.
> >>
> >> I've added aliases for haswell, sandybridge, ivybridge, bonnell,
> >> nehalem and silvermont.
> >>
> > Old names, like corei7, core-avx-i, atom, .. don't have precise
> > description for the processor. I think gcc driver should keep
> > accepting them. But they should be marked as undocumented
> > or deprecated. They should be removed from documentation.
>
> How about we leave these as -march=... to refer to the architecture,
> and reintroduce -mcpu= to refer to the exact cpu? Internally, the
> -mcpu would use some architecture specific base PTA_ attributes (as
> Jakub suggested) and would add some fine-tuning PTA_ attributes, based
> on -mcpu selection. This way, -march stays as is, and can still be
> used for some generally distributed binaries.
-mcpu is problematic, because it means various things among different
targets, and even on i?86/x86_64 it used to mean something already in the
past. Sometimes -mcpu= is what -march= is now on i?86/x86_64, sometimes
what -mtune= is. I'd say we don't need to deprecate anything, just add new
aliases for the sometimes harder to remember names. But everything just
IMHO.
Jakub
