disable ivopts by default for 4.0?

[Giovanni Bajo]

Nathanael Nerode <neroden@fastmail.fm> wrote:

> Disabling it by default (rendering the ivopts bugs non-regressions)
> would cut the regression list down to a reasonable and more
> manageable length.  Would it generate any new regressions?  I doubt
> it.

Only if you prove that it does not generate any codegen regression from older
versions of GCC, on any major platform. I do not think that starting disabling
problematic passes in GCC is a good shortcut to get the release out.

> It seems to be the cause of a lot of the remaining 4.0 regressions,
> including many of the wrong-code regressions.

I would debate this as well. There are around 200 regressions now, 80 of which
are already 3.4 or 3.3 regressions so they are not surely related of ivopts. Of
the other 120, I would be surprised if more than 15 are caused by ivopts. You
can setup a ivopts meta-bug, link all the regressions ivopts causes to this
meta-bug, and get back to us with some numbers.

Giovanni Bajo