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Date: Wed, 19 Oct 2016 13:31:16 +0200
From: Peter Zijlstra <peterz@infradead.org>
To: Richard Biener <rguenther@suse.de>
Cc: "Luis R. Rodriguez" <mcgrof@kernel.org>,
        Vegard Nossum <vegard.nossum@oracle.com>, Jiri Slaby <jslaby@suse.cz>,
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Subject: Re: [PATCH 01/12] extarray: define helpers for arrays defined in
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On Wed, Oct 19, 2016 at 01:11:31PM +0200, Richard Biener wrote:
> For C++ these kind of warnings trigger whenever abstraction penalty
> is removed.  Like the typical
> 
>  template <int i> foo () { if (i) { <code> } }
> 
> triggering for a hypothetical -Wdead-code for i == 0.  The kernel
> is known for its "C" abstraction stuff and I can believe that
> such -W flag would trigger for cases where abstraction is removed.

Sure, we very much rely on dead code elimination and constant
propagation all over the place. I was mostly thinking about the specific
case where it was triggered by alias analysis. I'm not sure how often
we'd trigger that.