i686-gcc vs i586-Suse Linux

i686-gcc vs i586-Suse Linux

[Ахметов Казбек]

Hi!

Г‘ould you give me a confirmation that:
'The installation of the 'i686' gcc is compatable with the 'i586' version of Suse Linux' ?

--
Best Regards,
 Akhmetov Kazbek                          mailto:k_akhmetov@af.kz

Re: i686-gcc vs i586-Suse Linux

[Andrew Haley]

??????? ?????? 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.

Re: i686-gcc vs i586-Suse Linux

[Martin Krischik]

Am 06.06.2007, 11:56 Uhr, schrieb Andrew Haley  
<aph-gcc@littlepinkcloud.COM>:

> ??????? ?????? 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.

SuSE only distristributes for i586! This is - of course - outdated so it  
is resonable to create a more modern tool chain on top. I do so as well.  
Mind you I would which for pentium4 - but that fails as cross compile is  
still flacky. But that is a diffrent story.

Martin

RE: 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.
> 

RE: i686-gcc vs i586-Suse Linux

[Andrew Haley]

Atwood, Robert C writes:
 >  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?"

That depends on the processor the poster is using.  If it's an i686,
everything will be fine.  But the poster didn't tell us.

Andrew.

RE: i686-gcc vs i586-Suse Linux

[Atwood, Robert C]

> That depends on the processor the poster is using.  If it's an i686,
> everything will be fine.  But the poster didn't tell us.
> 
> Andrew. 

A good point indeed. As the owner of a still-functioning 10-year old
laptop with a pentium processor I should not assume that others always
have the same processor as that which I have SUSe running on. (the
laptop's running a slackware 10 distro)


How much does it matter whether the gcc is built with i686 options
versus i586 or even i386, assuming you're actually using i686 type of
processor, if you then use that gcc to build an application using i686
options? 

Re: i686-gcc vs i586-Suse Linux

[Martin Krischik]

Am 06.06.2007, 23:30 Uhr, schrieb Atwood, Robert C  
<r.atwood@imperial.ac.uk>:

> How much does it matter whether the gcc is built with i686 options
> versus i586 or even i386, assuming you're actually using i686 type of
> processor, if you then use that gcc to build an application using i686
> options?

Recompiling some cygwin tools (cycwin-pc-i386) to pentium4-pc-cygwin  
improved performace quite a bit. So yes it matters.

Martin

Re: i686-gcc vs i586-Suse Linux

[Martin Krischik]

Am 06.06.2007, 11:56 Uhr, schrieb Andrew Haley  
<aph-gcc@littlepinkcloud.COM>:

> ??????? ?????? 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.

SuSE only distristributes for i586! This is - of course - outdated so it  
is resonable to create a more modern tool chain on top. I do so as well.  
Mind you I would which for pentium4 - but that fails as cross compile is  
still flacky. But that is a diffrent story.

Martin

Re: i686-gcc vs i586-Suse Linux

[Andrew Haley]

Martin Krischik writes:
 > Am 06.06.2007, 11:56 Uhr, schrieb Andrew Haley  
 > <aph-gcc@littlepinkcloud.COM>:
 > 
 > > ??????? ?????? 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.
 > 
 > SuSE only distristributes for i586! This is - of course - outdated
 > so it is resonable to create a more modern tool chain on top. I do
 > so as well.  Mind you I would which for pentium4 - but that fails
 > as cross compile is still flacky. But that is a diffrent story.

Fair enough.  i586 and i686 use the same ABI, and there shouldn't be
any cases where running i686 compilers on top of a GNU/Linux system
built for i586 will cause any problems.

Andrew.