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Re: Is it OK that gcc optimizes away overflow check?

From: me22 <me22 dot ca at gmail dot com>
To: Agner Fog <agner at agner dot org>
Cc: Ian Lance Taylor <iant at google dot com>, gcc-help at gcc dot gnu dot org
Date: Mon, 25 Jul 2011 10:18:12 -0700
Subject: Re: Is it OK that gcc optimizes away overflow check?
References: <4E2B2B72.9050504@agner.org> <mcr4o2arj57.fsf@coign.corp.google.com> <4E2D29DE.7060308@agner.org>

On Mon, Jul 25, 2011 at 01:31, Agner Fog <agner@agner.org> wrote:
>
> My point is that you are over-interpreting the standard when you conclude
> that the compiler is allowed to do anything in case of overflow.
>

How is signed overflow any different from dereferencing a null
pointer? UB is UB.

References:
- Is it OK that gcc optimizes away overflow check?
  - From: Agner Fog
- Re: Is it OK that gcc optimizes away overflow check?
  - From: Ian Lance Taylor
- Re: Is it OK that gcc optimizes away overflow check?
  - From: Agner Fog

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