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Date: Wed, 1 Nov 2000 10:22:16 -0800
From: Richard Henderson <rth@twiddle.net>
To: tytso@mit.edu
Cc: Martin Dalecki <dalecki@evision-ventures.com>,
        Jakub Jelinek <jakub@redhat.com>,
        Horst von Brand <vonbrand@sleipnir.valparaiso.cl>,
        linux-kernel@vger.kernel.org
Subject: Re: 2.4.0-test10-pre6: Use of abs()
Message-ID: <20001101102216.A18206@twiddle.net>
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On Wed, Nov 01, 2000 at 09:46:19AM -0500, tytso@mit.edu wrote:
> What versions of gcc produce the built-in functions?

2.95 and previous.  In 2.96 somewhere we fixed a bug that
automatically prototypes these builtin functions for you;
ie with current code you get an undeclared function warning.

> And does it do so for *all* platforms?  (i.e., PPC, Alpha,
> IA64, etc., etc., etc.)

Yes.  The thing about abs, though, is that it's "int abs(int)"
which does naughty things with longs on 64-bit targets.  You're
much better off writing (x < 0 ? -x : x) directly.


r~
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