[PING]^N Fix ppc64 bootstrap with a -m32 host compiler

[Richard Guenther]

On Thu, 22 Jun 2006, DJ Delorie wrote:

> 
> > Right, but this isn't happening currently.  Or I confuse what you mean
> > with "host" libiberty - libiberty is only build for the host, not for
> > the target, no?
> 
> Build libiberty is used to link gen*, programs that *run* *during* the
> build.
> 
> Host libiberty is used to link gcc et al, programs that run *after*
> the build, i.e. on the *host* you configured for.
> 
> Target libiberty is used to link programs built by the new gcc,
> programs that will run on the *target* you configured for.
> 
> Consider a canadian - I'm using my linux box to build a gcc.exe that
> will run under cygwin and produce m32c images.  $build_cc is linux's
> native gcc, which builds gen*, which run on the linux box during the
> build.  These have to link with a linux libiberty.  $host_cc is going
> to be a linux-x-cygwin cross compiler, so that the resulting gcc.exe
> runs on cygwin.  This gcc.exe needs to be linked with a cygwin
> libiberty.  When I run that gcc.exe on cygwin, I'll also need an m32c
> libiberty for my rom image.

Thanks for the explanation.

> > The problem is that while host and target are ppc64, build is ppc32.
> 
> The problem is that in stage2, build is *still* ppc32, but should
> build be ppc64 now?  If build is still ppc32, we want 32-bit libiberty
> and 32-bit genfoo.  If build is supposed to be ppc64, we want 64-bit
> *build* libiberty and 64-bit genfoo.  In either case, we're building a
> 64-bit gcc.

Yes, we're building a 64bit gcc.  And we definitely _start_ with a ppc32
build (actually, a ppc64 gcc that defaults to -m32).  Now, build needs
to "change" if we want to bootstrap that ppc64 compiler, correct?  Only
if we build it as a canadian cross ppc32 -> ppc64 x ppc64 then it need
not to change, but then we're not bootstrapping.

So, it would be nice to be able to bootstrap in this "semi-canadian-cross"
configuration in some way automatically.  It's certainly useful on
any bi-arch system or for building a native i686 compiler on ia64
(ok, that's a joke ;))

Richard.

--
Richard Guenther <rguenther@suse.de>
Novell / SUSE Labs