On Thu, Jan 25, 2018 at 3:13 PM, Peter Robinson <pbrobinson(a)gmail.com> wrote:
On Thu, Jan 25, 2018 at 3:02 PM, Florian Weimer
> On 01/25/2018 03:52 PM, Peter Robinson wrote:
>> On Thu, Jan 25, 2018 at 2:46 PM, Florian Weimer <fweimer(a)redhat.com>
>>> GCC offers a generic tuning option for Arm these days, but we select
>>> -mtune=cortex-8a instead.
>>> Is this still a good choice?
>> I suspect the generic tuning is likely a better choice, is there any
>> details about it anywhere? Basically Cortex-A8 is pretty much the
>> lowest common denominator for ARMv7
> The generic tuning has this:
So reading the gcc docs  it seems that generic-armv7-a makes sense.
To quote "should tune the performance for a blend of processors within
architecture arch. The aim is to generate code that run well on the
current most popular processors, balancing between optimizations that
benefit some CPUs in the range, and avoiding performance pitfalls of
We still support a number of Cortex-A8 devices but we have a lot more
Cortex_A7/9/15 devices these days too so I think generic makes sense
I also wonder whether it's worthwhile using neon-vfpv3, I can't tell
from the docs though if a SoC doesn't have neon if it will fall back
to VFP3 or just fail altogether.