Re: df.c and partial writes/REG_EQUAL notes

[kenner at vlsi1 dot ultra dot nyu dot edu (Richard Kenner)]

    Saying "I don't think we need 3 bitmap implemenations" is not a
    review of a patch.

If the patch in question adds a third bitmap implementation, it *is* a review
of the patch.

If somebody submits a patch based on a concept with which I disagree and I
review the patch, I'll just say that I don't think the concept behind the
patch is reasonable.  In that case, there's no reason to delve further into
the details of the patch, including the quality of the documentation.

    Overall direction and whatnot of the compiler is not controlled by
    [a specific global-write privilege maintainer], it's controlled by the
    steering committee.

True, but the SC has made it clear they do not want to get involved in the
review process of individual patches, only in setting that process, which is
that *somebody* with global write privileges must be convinced to approve the
patch.  In the case of a *major* issue, I agree it's appropriate to raise it
with the SC, but I doubt the SC wants to get involved at this level of
technical detail.

As to my opinion of the underlying issue, I'll say first that I have not
looked at the patch.  However, I agree with RTH that we don't need *three*
bitmap implementations.  That being said, however, I could be convinced that
a patch that added one was reasonable *if* I was convinced that this
implementation was vastly superior in some way *and* that there was a clear
path towards going back to two (or, better yet, one) such implmentation and I
trusted the submitter to do that.  Note that the last criteria means that I
(and presumably others) would have different opinions on the issue based on
the GCC development history of the submitter.