[Fedora-packaging] Macro %{optflags}

[Garrett Holmstrom]

On 9/18/2010 13:15, Sergio Belkin wrote:
> 2010/9/18 Mattias Ellert<mattias.ellert at fysast.uu.se>:
>> Using -mtune=atom is the correct flag when building ix86 rpms for the
>> most recent Fedora releases. The optflags are by design the same on any
>> ix86 installation - they do not change depending on what hardware is
>> present on the build machine. That you are building on a netbook does
>> not influence what %optflags is expanded into.
>>
>>         Mattias
>>
>>
>
> Mmm... Now I am a bit confused. So... Isn't  "-mtune" an optimization
> flag for a specific target arch. ?
>
>
> Please correct me if I'am wrong :)

You are mostly right, but it is "-march" that defines the instruction 
set to be used.  "-mtune" chooses which CPU the compiler will try to 
optimize for within the limits of the chosen instruction set.  Fedora 
uses "atom" for this value, but that does not make it incompatible with 
other hardware.