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Re: bug?
- To: Alexandre Oliva <aoliva at redhat dot com>
- Subject: Re: bug?
- From: Ingo Krabbe <ikrabbe at earthling dot net>
- Date: Tue, 19 Jun 2001 09:04:07 +0200 (CEST)
- cc: David Berthelot <davidb at Magma-DA dot COM>, Ben Kohlen <bckohlen at yahoo dot com>, <gcc-help at gcc dot gnu dot org>
- Reply-To: Ingo Krabbe <i dot krabbe at dokom dot net>
On 19 Jun 2001, Alexandre Oliva wrote:
> On Jun 18, 2001, Ingo Krabbe <ikrabbe@earthling.net> wrote:
>
> > Hmm, I see that we can also do
> > x & (~(x^x)>>n) which is really easier :-)
>
> This is only well-defined if x's type is unsigned. The behavior of
> right-shifting negative values is undefined (or unspecified?)
>
That's a kind of why I used ~(~(x^x)<<(sizeof(x)*8-n)).
CU INGO