From: "H. J. Lu" <hjl@lucon.org>
To: Jan Hubicka <hubicka@ucw.cz>
Cc: gcc@gcc.gnu.org
Subject: Re: Redundant instructions in loop optimization for x86-64?
Date: Fri, 10 Sep 2004 17:35:00 -0000 [thread overview]
Message-ID: <20040910165450.GA8456@lucon.org> (raw)
In-Reply-To: <20040910095023.GF378@atrey.karlin.mff.cuni.cz>
On Fri, Sep 10, 2004 at 11:50:23AM +0200, Jan Hubicka wrote:
> > It seems that gcc 3.4 and 4.0 generate redundant instructions in loop
> > optimization for x86-64:
> >
> > http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17387
> >
> > Does anyone know why?
>
> It is a zero extension GCC believe to be essential.
Is there a way to tell gcc that 32bit zero extension isn't needed for
x86-64?
H.J.
next prev parent reply other threads:[~2004-09-10 16:54 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-09-10 0:22 H. J. Lu
2004-09-10 10:17 ` Jan Hubicka
2004-09-10 17:35 ` H. J. Lu [this message]
2004-09-10 22:15 ` James E Wilson
2004-09-10 23:44 ` H. J. Lu
2004-09-11 0:10 ` James E Wilson
2004-09-11 1:58 ` Jan Hubicka
2004-09-11 11:51 ` Jan Hubicka
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