Re: Can I do 64-bit gcc compilation on 64-bit RedHat platform ?

Bob Techentin wrote:
> "Shaun Deacon" <sdeacon@fma.fujitsu.com> wrote
>>...can I actually do 64-bit compilation of Tcl/Tk
>>with gcc (tcl/tk 8.3.5) ?
>>
>>The reason I ask is that the configure script
>>returns the following warning :
>>
>>"64bit support being disabled -- don't know magic
>>for this platform"
>>
>>Looking inside the config script, I don't see
>>where "-m64" is ever enabled for gcc ?

> The --enable-64bit support is checked in the macros in tcl.m4. I only see
> 64bit support checks for AIX, HPUX, IRIX, and SunOS-5. Linux on 64 bit AMD
> or Intel processors is a relatively new thing, and it isn't supported in
> Tcl, yet.
>
> So the answer is "No, you can't compile 64 bit Tcl on Red Hat Enterprise
> Linux." I seriously doubt that your commercial application was compiled on
> Red Hat Linux with 64bit Tcl. You should be just fine with a regular, 32
> bit build.

Tcl builds fine for 64-bit Linux x86_64 systems (we have some,
we build it). The trick is to build locally, as the gcc
toolchain defaults to 64-bit builds on a 64-bit Linux machine
(no need for --enable-64bit, no special gcc flags).

Also, the 32-bit builds should work just fine as well. What
won't work is the cross-compile type builds - building a
64-bit build on a 32-bit gcc or vice versa.

This differs from "big iron" systems because they default to
32-bit builds, even on 64-bit capable platforms.

-- 
   Jeff Hobbs, The Tcl Guy
   http://www.ActiveState.com/, a division of Sophos