Re: [patch] Loop distribution for single nested loops

[Mark Mitchell <mark at codesourcery dot com>]

Diego Novillo wrote:

> As it was submitted during stage 2 and it's not enabled by default, I
> think it should be acceptable for 4.3.  However, if Richard does not
> agree, then let's discuss it a bit more.
> 
> Maybe Mark has something to say as the RM?  Mark, this is a new loop
> pass that is not enabled by default.  It was submitted during stage 2,
> but the review and feedback was not completed until now.  Should we hold
> it until 4.4?

I don't think enabled-by-default is a good decision criteria for these
things.  "Technology previews' are fine -- but I believe that releasing
code that isn't well-tested just hurts us.  In practice, people find the
documentation for these options, turn them on, notice that small
examples work great, and then find problems in large programs.  I think
the GCC project is better served by ensuring that these things aren't
released until we're confident in them.  I'm certainly aware of the
"more testing" argument -- but I think testing ought to be done by us.
We could always put out a "alpha release" if we feel it necessary.

Anyhow, as to this particular case, I think we ought to hold off until
4.4.  If we don't think it's solid enough to be enabled by default, then
it's not really going to help people much, so let's wait until 4.4.  If,
on the other hand, we think it *is* solid, and makes a difference, then
we can reconsider putting it into 4.3.

Thanks,

-- 
Mark Mitchell
CodeSourcery
mark@codesourcery.com
(650) 331-3385 x713