[Slackbuilds-users] sse2 optimisation

[Rob McGee]

On Sat, Jun 26, 2010 at 11:49:43AM -0500, Patrick J. Volkerding 
   wrote:
> On 06/26/2010 07:58 AM, David Spencer wrote:
>> I'm doing a SlackBuild for Luminance HDR.  Its compiler flags 
>> assume that SSE2 instructions are available.  That's a bad 
>> assumption, but it's easy to make it configurable with a
>> variable SSE2=yes|no and a note in the README.
>>
>> So, here's my question.  Should the SlackBuild's default be 
>> SSE2=yes, or SSE2=no?  There are three obvious choices.
>
> What about something like this?
>
> if grep -wq sse2 /proc/cpuinfo ; then
>   SSE2=yes
> else
>   SSE2=no
> fi
>
> Just a thought.

But that comes out wrong if being built for a different machine, 
which could easily be the case. Perhaps augment it with a check of 
the variable:

if [ -z "$SSE2" ] ; then true
elif grep -wq sse2 /proc/cpuinfo ; then ...
-- 
    Rob McGee - /dev/rob0 - rob0 at slackbuilds.org