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From: Florian Weimer <fweimer@redhat.com>
To: Adrian Moreno via Gcc-help <gcc-help@gcc.gnu.org>
Cc: David Brown <david.brown@hesbynett.no>,  Stefan Ring
 <stefanrin@gmail.com>,  Adrian Moreno <amorenoz@redhat.com>
Subject: Re: broken code only when optimized "-O2"
References: <cc01d4b4-ab21-febe-2ae4-197cfdca1816@redhat.com>
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 <9b28799e-71f8-2ef9-1cc9-01345993cc11@redhat.com>
Date: Wed, 22 Dec 2021 11:27:36 +0100
In-Reply-To: <9b28799e-71f8-2ef9-1cc9-01345993cc11@redhat.com> (Adrian Moreno
 via Gcc-help's message of "Wed, 22 Dec 2021 10:24:28 +0100")
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* Adrian Moreno via Gcc-help:

> So here I do not know what the compiler would think about "pos" if it
> happens to point to some invalid stack address.

In such cases, the compiler typically assumes that the code in question
is never executed.  This means that the comparison does not need to be
performed, among other things.

Thanks,
Florian