From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 9895 invoked by alias); 22 Aug 2009 04:14:23 -0000 Received: (qmail 9886 invoked by uid 22791); 22 Aug 2009 04:14:23 -0000 X-SWARE-Spam-Status: No, hits=-1.7 required=5.0 tests=AWL,BAYES_00,SARE_MSGID_LONG40,SPF_PASS X-Spam-Check-By: sourceware.org Received: from mail-yw0-f178.google.com (HELO mail-yw0-f178.google.com) (209.85.211.178) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Sat, 22 Aug 2009 04:14:14 +0000 Received: by ywh8 with SMTP id 8so1432930ywh.8 for ; Fri, 21 Aug 2009 21:14:12 -0700 (PDT) MIME-Version: 1.0 Received: by 10.150.44.21 with SMTP id r21mr3568912ybr.78.1250914452068; Fri, 21 Aug 2009 21:14:12 -0700 (PDT) In-Reply-To: <571f6b510908210237m2aba636v129a6f5a1a18783b@mail.gmail.com> References: <4A8E5127.50709@gnu.org> <571f6b510908210237m2aba636v129a6f5a1a18783b@mail.gmail.com> Date: Sat, 22 Aug 2009 15:18:00 -0000 Message-ID: <4aca3dc20908212114ibad20f5rcd9d148b08a2f846@mail.gmail.com> Subject: Re: Work on gc-improv branch From: Daniel Berlin To: Steven Bosscher Cc: Laurynas Biveinis , Paolo Bonzini , gcc@gcc.gnu.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable X-IsSubscribed: yes Mailing-List: contact gcc-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-owner@gcc.gnu.org X-SW-Source: 2009-08/txt/msg00406.txt.bz2 On Fri, Aug 21, 2009 at 5:37 AM, Steven Bosscher wro= te: > On Fri, Aug 21, 2009 at 10:52 AM, Laurynas > Biveinis wrote: >>>> BTW, it does not deal with types that in some instances have variables >>>> allocated in proper GC way (with a path from GC root) and in some >>>> instances not. Fixing these is going to be hard. >>> >>> Do you have some examples? >> >> Trees and rtxes mostly. > > Not to discourage you, but, eh... -- wouldn't it be a much more useful > project to move RTL out of GC space completely instead of improving GC > for rtxes? =A0The life time of RTL is pretty well defined by now and > much of the unwieldly GC / GTY (and, in fact PCH) code would go away > if RTL would just live on obstacks again. > One problem with obstacks was that it didn't allow freeing of stuff in the middle, so the high watermark for passes could be quite high unless you used many obstacks. It would be trivial to make an arena-style allocator that took care of this problem, however.