Re: [Discuss-gnuradio] Error on OSX in latest VOLK

[Josh Blum]

On 04/18/2012 09:24 AM, Josh Blum wrote:
> 
> 
> On 04/18/2012 09:23 AM, Nick Foster wrote:
>> On Wed, Apr 18, 2012 at 8:03 AM, Michael Dickens <address@hidden> wrote:
>>
>>> Yes: gcc 4.2.1.  Apple is transitioning from pure gcc to using llvm /
>>> clang, so maybe they'll keep those more up to date?  XCode 4.3.2 (latest)
>>> provides gcc 4.2.1 using llvm / clang (3.0), which is the latest release of
>>> those.  llvm / clang 3.1 is coming out soon, it looks like; so, we'll see.
>>>  In the mean time, I'm stuck with Apple's gcc 4.2.1 variant.  So, I'm sure
>>> there's a way to make it work with what VOLK is trying to do; but, that's
>>> an SEP < http://en.wikipedia.org/wiki/Somebody_Else's_Problem > both
>>> since I don't have time right now and that it's a little beyond my current
>>> expertise in assembly language programming.  Hopefully the
>>> VOLK-programmers-that-be can find a quick fix. - MLD
>>>
>>> On Apr 18, 2012, at 9:40 AM, Philip Balister wrote:
>>>
>>>> On 04/18/2012 09:28 AM, Michael Dickens wrote:
>>>>> I just pulled the latest GIT master, cleaned out everything old, then
>>> the usual cmake.  Make errors out with:
>>>>>
>>>>> [  3%] Building C object volk/lib/CMakeFiles/volk.dir/volk_cpu.c.o
>>>>> /var/tmp//ccrCnwC2.s:221:no such instruction: `xgetbv'
>>>>>
>>>>> I'm running OSX 10.6.8, XCode 3.2.3, gcc 4.2.1. - MLD
>>>>
>>>> gcc 4.2.1? Seriously?
>>>
>>
>> Thanks for the update, that's good to know Apple's antediluvian assembler
>> doesn't yet support AVX instructions. Actually, now that I look at it,
>> looks like GCC didn't support AVX until 4.6.0. We'll put in a check
>> disabling AVX if CMake doesn't find GCC 4.6. Unfortunately, there's no safe
>> way to enable AVX instructions without using xgetbv.
>>
> 
> Maybe the xgetbv stuff still needs and ifdef __AVX__ around it
> 
> __AVX__ is only defined when the -mavx is passed
> 

I take it back, we dont pass arch flags to volk_cpu.c
We can manually define something from the build system when -mavx
passes, or a compile time test, or maybe there is another gcc define.

-josh