From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 14418 invoked by alias); 6 Jan 2003 04:53:19 -0000 Mailing-List: contact gcc-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Archive: List-Post: List-Help: Sender: gcc-owner@gcc.gnu.org Received: (qmail 14404 invoked from network); 6 Jan 2003 04:53:16 -0000 Received: from unknown (HELO conure.mail.pas.earthlink.net) (207.217.120.54) by 209.249.29.67 with SMTP; 6 Jan 2003 04:53:16 -0000 Received: from ilmasc01-52.midwest.net ([209.248.16.62] helo=there) by conure.mail.pas.earthlink.net with smtp (Exim 3.33 #1) id 18VPG0-0004tV-00; Sun, 05 Jan 2003 20:53:01 -0800 Content-Type: text/plain; charset="iso-8859-1" From: Andy Walker To: dewar@gnat.com (Robert Dewar), denisc@overta.ru Subject: Re: Synthetic register related: consequences of changing Frame layout. Date: Mon, 06 Jan 2003 05:01:00 -0000 Cc: gcc@gcc.gnu.org References: <20030105114048.DAAFDF2E18@nile.gnat.com> In-Reply-To: <20030105114048.DAAFDF2E18@nile.gnat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Message-Id: X-SW-Source: 2003-01/txt/msg00254.txt.bz2 On Sunday 05 January 2003 05:40 am, Robert Dewar wrote: > Have you even looked at how code is currently > generated. Yes. > Registers are spilled to the local stack frame, and of course > you get the normal 3-byte instructions to transfer to and from the spill > locations. With Synthetic registers, you also get a nice set of instructions to handle data directly in the Synthetic registers without needing any transfer to a natural register -- add, add immediate, xor, neg, rotr, to name a few. Another big plus is that Synthetic registers are directly used in instructions, instead of requiring a move from a spill location to a natural register before being used. > There is too much general "I believe" guesswork in your approach > and not enough hard knowledge. I can only agree. >From experience, I hope to gain wisdom. Andy