Message-ID: <4FC81611.9090801@att.net>
Date: Thu, 31 May 2012 20:08:33 -0500
From: Daniel Santos <danielfsantos@att.net>
Reply-To: daniel.santos@pobox.com
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CC: Kent Overstreet <koverstreet@google.com>, tj@kernel.org,
        Peter Zijlstra <peterz@infradead.org>, axboe@kernel.dk,
        paul.gortmaker@windriver.com, Andi Kleen <andi@firstfloor.org>
Subject: Re: [PATCH v2 1/3] [RFC] Generic Red-Black Trees
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Oh yeah, so the patch set I sent boots & runs fine.  I've also noticed
that I have a few outdated doc-comments and a mistake in the
doc-comments for
the BUILD_BUG_ON_NON_CONST2() macro, under the "Normal Variables"
section, the text "global non-static const broken until 4.2 (-O1 broken
until 4.4)" contradicts the earlier statement that all const values
should never fail. This only applies to floats (but not doubles), which
we don't have to worry about in the kernel anyway. (incidentally, their
behavior under __builtin_constant_p() varies quite a bit until gcc 4.4,
where it's fine)

It was important for me to figure out what was and wasn't working with
__builtin_constant_p(), and in what versions of gcc because this
implementation relies heavily on the compiler optimizing out code based
upon values pass to it via a const struct pointer.  Also, I was looking
for other possibilities, as I continued discovered broken (improperly
optimized) scenarios.

Daniel
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