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c.f. bug 424647
List Archive: gentoo-amd64
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To: gentoo-amd64@g.o
From: Frank Peters <frank.peters@...>
Subject: Re: Re: GCC-4.5.2 Has Serious Problems
Date: Thu, 30 Jun 2011 20:04:24 -0400
On Fri, 01 Jul 2011 02:44:36 +0300
Nikos Chantziaras <realnc@...> wrote:

> >
> > Your code is buggy, because you're breaking C's aliasing rules. You are
> > not allowed to use a different pointer type to dereference a variable of
> > a different type. Doing so results in undefined behavior.
> 

Well, the error occurs only within the loop structure.  If
I manually "unroll" the loop using the same pointers there
is no error when compiled with "O2." 

IOW, the problem is how the loop is optimized under -O2.

Frank Peters



Replies:
Re: GCC-4.5.2 Has Serious Problems
-- Nikos Chantziaras
References:
GCC-4.5.2 Has Serious Problems
-- Frank Peters
Re: GCC-4.5.2 Has Serious Problems
-- Nikos Chantziaras
Re: GCC-4.5.2 Has Serious Problems
-- Nikos Chantziaras
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Updated Jun 28, 2012

Summary: Archive of the gentoo-amd64 mailing list.

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