i686-gcc vs i586-Suse Linux

[Atwood, Robert C]

 I think what the poster means is 

"If the  Linux kernel, and possibly some other applications provided by a Gnu/Linux distribution provider(Suse),  have been configured and built with 'i586' options, should there be any problems with using a gcc configured and built with 'i686' options, or the programs built using that compiler?"

My limited knowledge says there should not be a problem, just because the _kernel_ is set not to use MMX instructions doesn't mean a compiled program cannot do so, AFAIK ,  if this is not the case I'd like to know too!  I have built my own GCC using such options and have built my own applications using processor-specific options using the rsulting GCC, for a number of GCC versions since 3 up to and including 4.2 ,   on a system in which virtually everything else is stock SUSE 10.0 or previously RedHat 7.2, and so far I have not encountered any problems. 
 
Disclaimer, I am not part of the gcc development team and my advice is worth what you paid for it, is not covered by a warranty and is not an official confirmation of anything ;-6



> -----Original Message-----
> From: gcc-help-owner@gcc.gnu.org 
> [mailto:gcc-help-owner@gcc.gnu.org] On Behalf Of Andrew Haley
> Sent: 06 June 2007 09:56
> To: Ахметов Казбек
> Cc: gcc-help@gcc.gnu.org
> Subject: Re: i686-gcc vs i586-Suse Linux
> 
> ??????? ?????? writes:
> 
>  > ?ould you give me a confirmation that:
> 
>  > 'The installation of the 'i686' gcc is compatable with the 'i586'
>  > version of Suse Linux' ?
> 
> I don't really understand why you're asking this.  If you have a i586
> system, why not configure gcc for the i586 ?
> 
> The most significant difference between i586 (Pentium) and i686
> (Pentium Pro) from gcc's point of view is MMX instructions.
> 
> Andrew.
>