As of the latest version of OpenBLAS, it now reports which CPU family it's 
using the optimized kernels for in its info string. If you build for a 
particular fixed family it appears in upper case, if it's selected 
dynamically then it shows with just the first letter capitalized. If your 
OpenBLAS was built with DYNAMIC_ARCH enabled, then you can actually 
dynamically choose a different family by setting the environment variable 
OPENBLAS_CORETYPE.


On Saturday, July 19, 2014 7:51:59 AM UTC-7, Elliot Saba wrote:
>
> You can get some limited information by running versioninfo(true) at the 
> julia prompt.  There are certain things that are recorded, and one of them 
> is the commandline that is passed to OpenBLAS when building Julia.  I 
> believe that is what you are referring to when talking about Sandy Bridge 
> and Nehalem.  By default, OpenBLAS will target the highest CPU capability 
> that your CPU advertises it is capable of; so if your CPU is capable of 
> Sandy Bridge instructions, it will target Sandy Bridge and not Nehalem. 
>  You can force it to target a certain architecture however, and that 
> forcing would get recorded.
>
>
> On Sat, Jul 19, 2014 at 10:45 AM, Tomas Lycken <[email protected] 
> <javascript:>> wrote:
>
>> I decided to rebuild my Julia installation, and in the process try to 
>> optimize the build to my machine. As a first attempt, I just added a file 
>> Make.user to the Julia directory, with the single line "MARCH=native" in 
>> it. No other changes to the current master.
>>
>> Is there any way to inspect what options were actually used when 
>> building, other than digging around in the build scripts and try to deduce 
>> it myself? For example, I have a SandyBridge CPU, but if I understand the 
>> docs correctly the default arch is Nehalem. Is there a (simple) way to 
>> check that this was taken into account in my build?
>>
>> // Tomas
>>
>
>

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