Why -mtune=atom?

Florian Weimer fweimer at redhat.com
Thu Mar 12 17:16:37 UTC 2015

On 03/12/2015 04:56 PM, Stephen John Smoogen wrote:
> On 12 March 2015 at 07:02, Florian Weimer <fweimer at redhat.com> wrote:
>> The default CFLAGS set by RPM include “-mtune-atom”.
>> Why?  I doubt Atom CPUs are Fedora's primary target.  It's not even a
>> documented GCC option.  There is such a wide variety of CPUs under this
>> label that it's not even clear what it would mean.

> Could you list your concerns? Is it causing problems? Are you wanting a
> different target? I think that would help aim the conversation a bit better.

See below:

>> If it's better than “-mtune=generic” or the GCC default, shouldn't GCC
>> be fixed?

I looked at GCC, and -mtune=atom is actually -mtune=bonnell, and there
is now -mtune=silvermont.  Bay Trail and Avoton/Rangeley, the current
SoC families, belong to Silvermont, not Bonnell.

(And no, i686 binaries aren't just for enthusiasts.  I expect that users
who run 32-bit software with them on x86_64 installations are also

Florian Weimer / Red Hat Product Security

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