RFC: Removing OLD_EXCEPTIONS powerpc multilib variants

Ralf Corsepius ralf.corsepius at rtems.org
Thu Feb 10 02:17:26 UTC 2005


On Wed, 2005-02-09 at 09:47 -0800, Till Straumann wrote:
> I don't understand the need for a toolchain variant
> for the exception model in the first place -- what
> different features does OLD_EXCEPTIONS trigger in
> libgcc/newlib/... ??
As far as code generation is concerned: None.

What introduces this need is RTEMS's cpukit. It contains code which is
conditionally compiled, based on pre-defined defines distinguishing
between old- and new- exception processing.

Now, the problem is the sheer amount of defines being used by the
powerpc port and identifying which of them are conditionally being used
based on old-/new-exception processing.

It's simply as this: Oversight has gone lost.

> I believe this to be pure bloat anyways.
In an ideal world - yes. Historically - no.

If you can prove that there is no code in cpu which is conditionally
being compiled for old-exception/new-exception processing, these
multilib variants can be removed.

In the past, this did not apply. Since then, a lot as changed, and I am
close to be able to prove or counter-prove this - However, I am still
not there.

>  It only would
> matter if you intend to create RTEMS libcpu variants
> - one for the old and one for the 'new' exception model.
Right, that's what I am aiming at - I have an experimental patch pending
which ATM moves ca. 50% of all the powerpc defines from cpukit to
libcpu.

Ralf





More information about the users mailing list