From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:39707)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <aurelien@aurel32.net>) id 1ZJeQN-0006xf-Do
	for qemu-devel@nongnu.org; Mon, 27 Jul 2015 05:10:20 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <aurelien@aurel32.net>) id 1ZJeQM-0007y9-AU
	for qemu-devel@nongnu.org; Mon, 27 Jul 2015 05:10:19 -0400
Received: from hall.aurel32.net ([2001:bc8:30d7:100::1]:42141)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <aurelien@aurel32.net>) id 1ZJeQM-0007xf-0i
	for qemu-devel@nongnu.org; Mon, 27 Jul 2015 05:10:18 -0400
Date: Mon, 27 Jul 2015 11:10:16 +0200
From: Aurelien Jarno <aurelien@aurel32.net>
Message-ID: <20150727091016.GD30591@aurel32.net>
References: <1437755447-10537-1-git-send-email-aurelien@aurel32.net>
	<1437755447-10537-4-git-send-email-aurelien@aurel32.net>
	<55B5EB14.9080702@redhat.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <55B5EB14.9080702@redhat.com>
Subject: Re: [Qemu-devel] [PATCH for-2.5 03/10] tcg/optimize: track
 const/copy status separately
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: qemu-devel@nongnu.org, Richard Henderson <rth@twiddle.net>

On 2015-07-27 10:25, Paolo Bonzini wrote:
> 
> 
> On 24/07/2015 18:30, Aurelien Jarno wrote:
> > Use two bools to track constants and copies instead of an enum.
> > 
> > Cc: Richard Henderson <rth@twiddle.net>
> > Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
> > ---
> >  tcg/optimize.c | 30 +++++++++++++++---------------
> >  1 file changed, 15 insertions(+), 15 deletions(-)
> > 
> > diff --git a/tcg/optimize.c b/tcg/optimize.c
> > index d2b63a4..f16eb1e 100644
> > --- a/tcg/optimize.c
> > +++ b/tcg/optimize.c
> > @@ -35,14 +35,9 @@
> >          glue(glue(case INDEX_op_, x), _i32):    \
> >          glue(glue(case INDEX_op_, x), _i64)
> >  
> > -typedef enum {
> > -    TCG_TEMP_UNDEF = 0,
> > -    TCG_TEMP_CONST,
> > -    TCG_TEMP_COPY,
> > -} tcg_temp_state;
> > -
> >  struct tcg_temp_info {
> > -    tcg_temp_state state;
> > +    bool is_const;
> > +    bool is_copy;
> 
> Could temps[arg].is_copy be replaced by temps[arg].next_copy != arg?
> 
> For example, this:
> 
>     if (temps[temp].prev_copy == temps[temp].next_copy) {
>         temps[temps[temp].next_copy].is_copy = false;
>     } else {
>         temps[temps[temp].next_copy].prev_copy = temps[temp].prev_copy;
>         temps[temps[temp].prev_copy].next_copy = temps[temp].next_copy;
>     }
> 
> would be replaced simply by
> 
>     temps[temps[temp].next_copy].prev_copy = temps[temp].prev_copy;
>     temps[temps[temp].prev_copy].next_copy = temps[temp].next_copy;
> 

That's an interesting idea, especially I have a patch series in
preparation that get rid of is_const. I will try to get something like
that for v2.

-- 
Aurelien Jarno                          GPG: 4096R/1DDD8C9B
aurelien@aurel32.net                 http://www.aurel32.net