From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.devel Subject: Re: MPS: weak hash tables Date: Sat, 06 Jul 2024 13:59:56 +0300 Message-ID: <86le2e4wgj.fsf@gnu.org> References: <864j946kbe.fsf@gnu.org> <3hUiHuwpNB-2QtvUKSxx3e3-ZUX_xSI4WMW-BDSuybaKMQ3WTjpI2oVBe4Xato-h8bE-d24VQq9I8tE4x-G1-wyKuBD8cGkwaFggC91ndNM=@protonmail.com> <86wmlz59uk.fsf@gnu.org> <86jzhz57iz.fsf@gnu.org> <9dD8TJnank8JpArVkh2SPWHAv07Ock1BliLAKmIthSJLfie-mHistAN6cU8sFuVlW_FSKsZOAjs-RZox5hknXSklMEXmGEGrojsyCHonwvY=@protonmail.com> Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="9800"; mail-complaints-to="usenet@ciao.gmane.io" Cc: gerd.moellmann@gmail.com, eller.helmut@gmail.com, emacs-devel@gnu.org To: Pip Cet Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Sat Jul 06 13:00:45 2024 Return-path: Envelope-to: ged-emacs-devel@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1sQ39o-0002ON-My for ged-emacs-devel@m.gmane-mx.org; Sat, 06 Jul 2024 13:00:44 +0200 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sQ397-0001CE-Ua; Sat, 06 Jul 2024 07:00:01 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sQ396-0001A6-FC for emacs-devel@gnu.org; Sat, 06 Jul 2024 07:00:00 -0400 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sQ396-0005Fw-5B; Sat, 06 Jul 2024 07:00:00 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=gnu.org; s=fencepost-gnu-org; h=References:Subject:In-Reply-To:To:From:Date: mime-version; bh=A1eiExOGMMg9uXfpp/+y/pTz3voyyt/jC0IxlQDtKdI=; b=HaBOG6Lrdsmv NoXuPYPc+9SHK9wwckjX8Rady6yVk0viZ8KUxoz0pHSmLhuq4Yv3oH8xKbS27J8CABKvhl1m+yo15 utruNXQ07QmTt+8iyyKHmZg/VnafFtlHWm/bDVcxQ7Nb58l5ITmBtkuxjZKp7IeRaJrSjB4iQby3Y IjUQmjUGin5lxKrQB5J3AJWE/oU7DtiKTTlOvgjG8dbHqj73rnnA3YpEysSQGRrj1/hQhEe2ntiPP iUMneV3Z1NJY29XiANbtFSv1iTcUwha5GV3+OZ160o5ZA1nf21eXJ6/JchHAuyxdW1u9Ryzkw0Qot hU1Oc33/QxUyu8t0BwC7Mg==; In-Reply-To: <9dD8TJnank8JpArVkh2SPWHAv07Ock1BliLAKmIthSJLfie-mHistAN6cU8sFuVlW_FSKsZOAjs-RZox5hknXSklMEXmGEGrojsyCHonwvY=@protonmail.com> (message from Pip Cet on Sat, 06 Jul 2024 09:13:04 +0000) X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.devel:321418 Archived-At: > Date: Sat, 06 Jul 2024 09:13:04 +0000 > From: Pip Cet > Cc: gerd.moellmann@gmail.com, eller.helmut@gmail.com, emacs-devel@gnu.org > > On Saturday, July 6th, 2024 at 07:00, Eli Zaretskii wrote: > > > Date: Sat, 06 Jul 2024 06:31:14 +0000 > > > > The way the WIDE_EMACS_INT configuration works, most Lisp objects have > > their high 30 bits (out of 64) cleared, the only exception being > > fixnums. > > Oh. I must be doing something else then, because I'm seeing objects like this one: > (gdb) p/x key $1 = 0xc0000000a7b4e4e8 > > IOW, MSB tags in the high 32 bits, a plain pointer in the low 32 bits. Isn't that what I said? Or do you mean my silly mistake of saying 30 instead of 28? > Can you tell me more about your build configuration? Just --with-wide-int, that's all. > > Not sure this answers or refutes some of what you wrote. At the time > > Gerd flatly declined to invest any effort in the WIDE_EMACS_INT build, > > or even explain what needs to be modified in igc.c and elsewhere to > > make that work, so my build of 32-bit Emacs doesn't use that, because > > I don't understand MPS innards well enough to do that on my own in > > what little time I have to dedicate to this branch. Just building MPS > > with MinGW (a configuration it doesn't support) in a way that passes > > its test suite was enough of an effort. I will be much happier if the > > WIDE_EMACS_INT would be supported on the branch. > > WIDE_EMACS_INT with LSB tags, which I don't think we currently support, might be possible. Using MSB tags would require some work, particularly for ambiguous scanning which might need to look at symbols, but I think it's also possible. Weak objects (not "options", sorry) require the whole non-alignment song and dance. Why would we want to support WIDE_EMACS_INT with LSB tags?