Re: 32->64 bit cross compilers

["Janis Johnson" <janis at us dot ibm dot com>]

On Tue, 24 Apr 2001, Mark Mitchell wrote:

> PR912 refers to a feature regression from GCC 2.95.x: we were at some
> point unable to cross-compiler from 32-bit machines to 64-bit machines
> to TImode popping up in libgcc2.h.
>
> I know we debated what to do about this, but I do not know how the
> debate ended.  Let's please not have the debate again, if we can help
> it.
>
> Instead, I would appreciate it if someone would:
>
>   - Tell me if the problem still exists.
>
>   - Point me at a summary of the outcome of the debate.
>
> If we haven't fixed this problem yet, we'll have to make a decision
> very soon about what to do, and I would like to be informed by the
> collective wisdom of the earlier discussion.

It's still broken for host ix86 and target ia64.  There was a discussion
of that earlier this month:

On Apr 3, 2001 Alexandre Oliva <aoliva@redhat.com> wrote:

> On Apr  2, 2001, Jim Wilson <wilson@cygnus.com> wrote:
>
> > In the Red Hat tools group, what we do is define HOST_WIDE_INT to
> > "long long" instead of "long" for cross compilers from 32-bit hosts
> > to 64-bit targets.  This is done via an ugly config.gcc hack.  This
> > makes the cross gcc run slower, but the resulting code will be much
> > closer to what you would get with a native compiler. [...] What it
> > really needs is someone to clean it up and make it more presentable
> > so that we can put it in the FSF tree.
>
> FWIW, I've just fixed (but not installed yet; will do momentarily) at
> least some of the bugs in codegen and in the ppc back-end, that
> prevented the adoption of the patch that automatically selected `long
> long' for HOST_WIDE_INT if the target has 64-bits wide longs, which
> obviates the ugly hack we currently have.

Is someone from Red Hat looking at cleaning up the config.gcc hack and
submitting it?

Janis