This is the mail archive of the gcc@gcc.gnu.org mailing list for the GCC project.

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]
Other format:	[Raw text]

Re: some integer undefined behaviors in gcc

From: Florian Weimer <fw at deneb dot enyo dot de>
To: Paolo Bonzini <bonzini at gnu dot org>
Cc: gcc at gcc dot gnu dot org
Date: Sun, 08 Aug 2010 14:17:11 +0200
Subject: Re: some integer undefined behaviors in gcc
References: <4C58A5E8.4040108@cs.utah.edu> <87tyn6hcv6.fsf@mid.deneb.enyo.de> <20100808085152.GA26629@prunille.vinc17.org> <87k4o14asi.fsf@mid.deneb.enyo.de> <4C5E9F66.4000008@gnu.org>

* Paolo Bonzini:

>> There quite a few instances of the x & -x pattern, which would be fine
>> with -fwrapv.
>
> It's always valid if you know that x is not INT_MIN, which you do in
> many cases (for example if x is an offset).

The reported cases cover the INT_MIN case (these are execution logs,
not results from static analysis).

References:
- some integer undefined behaviors in gcc
  - From: John Regehr
- Re: some integer undefined behaviors in gcc
  - From: Florian Weimer
- Re: some integer undefined behaviors in gcc
  - From: Vincent Lefevre
- Re: some integer undefined behaviors in gcc
  - From: Florian Weimer
- Re: some integer undefined behaviors in gcc
  - From: Paolo Bonzini

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]