[PATCH] Adding the loop vectorizer to the LTO pipeline

[Renato Golin]

On 21 February 2014 23:45, Chandler Carruth <chandlerc at gmail.com> wrote:
> So, not at all relevant to this particular case, but I wouldn't think about
> it that way. We want trunk to always be in a release quality state. That's
> why we revert to green. This is critically important to a bunch of users of
> LLVM that are cutting *many* releases from trunk with nothing to do with the
> open source releases. =]

I completely agree with you, and did not mean to make trunk unstable.

My point is that, since this has shown to be very positive in most
ways and not shown any conformance regression and little performance
regressions, that we could turn it on and "see what happens". This is
what we've done with the vectorizer last year and it worked quite
well. This is what we've done with the ARM IAS this year and helped us
find many problems which is now with a quality good enough to be
enabled by default from now on. The C++11 move is another example...

Sometimes, it's only breaking a little that you find most errors, but
you can't just break completely, and I take it that's your point. The
cost of reverting the vectorizer in LTO would be one simple commit and
enabling it now shouldn't created a wake of irreversible changes
depending on it. So, in this very specific case, I think it's ok to
try.

cheers,
--renato