[gentoo-user] Compiling 32 bit library on x86_64

[gentoo-user] Compiling 32 bit library on x86_64

[Roger Mason]

Hello,

I need to compile a 32 bit version of libtermcap on an x86_64 (multilib)
system.  Can someone tell me how to set up CFLAGS?  This is what I have
at the moment:

CFLAGS="-O2 -m32 -march=native -msse3 -pipe"
CXXFLAGS="-O2 -m32 -march=native -msse3 -pipe"

ebuild libtermcap-compat-2.0.8-r2.ebuild compile

ends with:

/usr/lib/gcc/x86_64-pc-linux-gnu/4.2.4/../../../../x86_64-pc-linux-gnu/bin/ld:
i386 architecture of input file `termcap.o' is incompatible with
i386:x86-64 output
/usr/lib/gcc/x86_64-pc-linux-gnu/4.2.4/../../../../x86_64-pc-linux-gnu/bin/ld:
i386 architecture of input file `tparam.o' is incompatible with
i386:x86-64 output
/usr/lib/gcc/x86_64-pc-linux-gnu/4.2.4/../../../../x86_64-pc-linux-gnu/bin/ld:
i386 architecture of input file `version.o' is incompatible with
i386:x86-64 output

Thanks,
Roger

Re: [gentoo-user] Compiling 32 bit library on x86_64

[David W Noon]

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On Fri, 30 Apr 2010 12:10:02 +0200, Roger Mason wrote about
[gentoo-user] Compiling 32 bit library on x86_64:

>Hello,
>
>I need to compile a 32 bit version of libtermcap on an x86_64
>(multilib) system.  Can someone tell me how to set up CFLAGS?  This is
>what I have at the moment:
>
>CFLAGS="-O2 -m32 -march=native -msse3 -pipe"
>CXXFLAGS="-O2 -m32 -march=native -msse3 -pipe"

The -march=native will shoot you in the foot. Pick a 32-bit
architecture and use that instead; e.g. -march=i686

Then, -msse3 could also be problematic, unless the target is a very late
model Pentium 4.  I would ditch that too.
-- 
Regards,

Dave  [RLU #314465]
======================================================================
dwnoon@ntlworld.com (David W Noon)
======================================================================

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Re: [gentoo-user] Compiling 32 bit library on x86_64

[Mike Edenfield]

On 4/30/2010 5:25 AM, Roger Mason wrote:
> Hello,
> 
> I need to compile a 32 bit version of libtermcap on an x86_64 (multilib)
> system.  Can someone tell me how to set up CFLAGS?  This is what I have
> at the moment:

Have you tried using sys-devel/crossdev?

It will set up the entire 32-bit cross-compiler environment for you;
then it's just a matter of setting a couple of environment variables to
switch compilers.

--Mike

Re: [gentoo-user] Compiling 32 bit library on x86_64

[Roger Mason]

David W Noon <dwnoon@ntlworld.com> writes:

> On Fri, 30 Apr 2010 12:10:02 +0200, Roger Mason wrote about
> [gentoo-user] Compiling 32 bit library on x86_64:
>
>>Hello,
>>
>>I need to compile a 32 bit version of libtermcap on an x86_64
>>(multilib) system.  Can someone tell me how to set up CFLAGS?  This is
>>what I have at the moment:
>>
>>CFLAGS="-O2 -m32 -march=native -msse3 -pipe"
>>CXXFLAGS="-O2 -m32 -march=native -msse3 -pipe"
>
> The -march=native will shoot you in the foot. Pick a 32-bit
> architecture and use that instead; e.g. -march=i686
>
> Then, -msse3 could also be problematic, unless the target is a very late
> model Pentium 4.  I would ditch that too.

Many thanks.  Interestingly enough, even though the build of libtermca
failed, the static library _was_ built and my application builds against
it just fine.

Roger

Re: [gentoo-user] Compiling 32 bit library on x86_64

[Roger Mason]

Mike Edenfield <kutulu@kutulu.org> writes:

> Have you tried using sys-devel/crossdev?

Not in the present context.

> It will set up the entire 32-bit cross-compiler environment for you;
> then it's just a matter of setting a couple of environment variables to
> switch compilers.

Some time ago I tried setting up cross-compilation so that I could use a
rather heterogeneous collection of amd64, ppc and x86 machines in
icecream.  Unfortunately I could not get cross-compilation to work.  I
asked about it in this forum but did not get any replies.

Cheers,
Roger

Re: [gentoo-user] Compiling 32 bit library on x86_64

[Mike Edenfield]

On 4/30/2010 12:40 PM, Roger Mason wrote:
> Mike Edenfield <kutulu@kutulu.org> writes:
> 
>> Have you tried using sys-devel/crossdev?
> 
> Not in the present context.
> 
>> It will set up the entire 32-bit cross-compiler environment for you;
>> then it's just a matter of setting a couple of environment variables to
>> switch compilers.
> 
> Some time ago I tried setting up cross-compilation so that I could use a
> rather heterogeneous collection of amd64, ppc and x86 machines in
> icecream.  Unfortunately I could not get cross-compilation to work.  I
> asked about it in this forum but did not get any replies.

I have it set up on my laptop. I admit it's been a while since I used
it, but I know it worked at one point.

Though I was using it on a standard PC, the best source of information I
found on the process was the Gentoo Embedded Handbook:


http://www.gentoo.org/proj/en/base/embedded/handbook/?part=1

The whole first section is on setting up a cross-compiler, just
substitute i686-pc-linux-gnu for your target architecture.

Re: [gentoo-user] Compiling 32 bit library on x86_64

[Roger Mason]

Mike Edenfield <kutulu@kutulu.org> writes:

> On 4/30/2010 12:40 PM, Roger Mason wrote:
>> Mike Edenfield <kutulu@kutulu.org> writes:
>> 
>>> Have you tried using sys-devel/crossdev?
>> 
>> Not in the present context.
>> 
>>> It will set up the entire 32-bit cross-compiler environment for you;
>>> then it's just a matter of setting a couple of environment variables to
>>> switch compilers.
>> 
>> Some time ago I tried setting up cross-compilation so that I could use a
>> rather heterogeneous collection of amd64, ppc and x86 machines in
>> icecream.  Unfortunately I could not get cross-compilation to work.  I
>> asked about it in this forum but did not get any replies.
>
> I have it set up on my laptop. I admit it's been a while since I used
> it, but I know it worked at one point.
>
> Though I was using it on a standard PC, the best source of information I
> found on the process was the Gentoo Embedded Handbook:
>
>
> http://www.gentoo.org/proj/en/base/embedded/handbook/?part=1
>
> The whole first section is on setting up a cross-compiler, just
> substitute i686-pc-linux-gnu for your target architecture.

Ah, thank you.  I'll have another go at it this summer.

Roger