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Date: Sun, 2 Mar 2003 14:03:25 -0800
From: Richard Henderson <rth@twiddle.net>
To: Werner Almesberger <wa@almesberger.net>
Cc: Ulrich Drepper <drepper@redhat.com>,
       Norbert Kiesel <nkiesel@tbdnetworks.com>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] Multiple & vs. && and | vs. || bugs in 2.4.20
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In-Reply-To: <20030302184114.Q2791@almesberger.net>; from wa@almesberger.net on Sun, Mar 02, 2003 at 06:41:14PM -0300
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On Sun, Mar 02, 2003 at 06:41:14PM -0300, Werner Almesberger wrote:
> While I agree with your observation in general, this is actually
> something the compiler should be able to figure out by itself:
> 
>  - there's only a side-effect if acm is NULL

In general there's also a side effect if acm is uninitialized.
I didn't look at the code in question here.

As for the rest, it's true that we should be able to do this,
but we don't currently have a pass that globally propagates
"trapiness" of memory references.  It would be a useful thing
to have though, particularly for Java, which is required to
arrange for these traps to be able to be caught with exceptions,
and other horrible reordering issues.


r~
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