From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 22006 invoked by alias); 3 Feb 2004 23:16:00 -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 21926 invoked from network); 3 Feb 2004 23:15:56 -0000 Received: from unknown (HELO mail.polimi.it) (131.175.12.67) by sources.redhat.com with SMTP; 3 Feb 2004 23:15:56 -0000 Received: from localhost (wpad.polimi.it [131.175.12.4]) by mail.polimi.it (Switch-3.0.5/Switch-3.0.0) with ESMTP id i13NFnr9016439; Wed, 4 Feb 2004 00:15:50 +0100 (MET) Received: from 151.29.221.54 ( [151.29.221.54]) as user paolo.bonzini@mail.polimi.it by webmail.polimi.it with HTTP; Wed, 4 Feb 2004 00:15:49 +0100 Message-ID: <1075850149.40202ba582c06@webmail.polimi.it> Date: Tue, 03 Feb 2004 23:16:00 -0000 From: Paolo Bonzini To: Zack Weinberg Cc: gcc@gcc.gnu.org Subject: Re: Getting rid of GET_RTX_CLASS? References: <004e01c3ea76$c081d300$8a41af83@kingkong> <20040203211454.GA16126@redhat.com> <87wu7397k4.fsf@egil.codesourcery.com> In-Reply-To: <87wu7397k4.fsf@egil.codesourcery.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit User-Agent: Internet Messaging Program (IMP) 3.1 X-Originating-IP: 151.29.221.54 X-Scanned-By: MIMEDefang 2.35 X-SW-Source: 2004-02/txt/msg00219.txt.bz2 > >> I'd like to turn rtx classes from characters to enums. Would this be > >> feasible? Interesting? It may result in slight compile time speedups, > >> also. > > Compact switch tables, presumably. Yes; lookup tables instead of binary searching. I also hope to learn something while reading the code -- low priority things are good for beginners (like me). I'd also like to introduce new predicates (like OBJECT_P I already have a patch for) that express conditions like GET_RTX_CLASS (x) == '2' || GET_RTX_CLASS (x) == '<' || GET_RTX_CLASS (x) == 'c' that abound in cse and other places that may be put under a diet after tree-ssa is merged. These could become GET_RTX_CLASS (x) >= BINARY && GET_RTX_CLASS (x) <= BINARY_COMMUTATIVE (cheaper) as long as this is found only once, in rtl.h. I suspect that an inordinate amount of time is spent in rtl.h if my very simple OBJECT_P patch had a 1% gain on bootstrap time. Paolo ------------------------------------------------- This mail sent through IMP: http://horde.org/imp/