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 09:10:43 +0300 Message-ID: <86wmlz59uk.fsf@gnu.org> References: <_mNcR6ailVKpYHLxgfo_tJlYGeR0AQIzQWluspYYp5_g5pIIKkHLNfFkklQQgOKNiVW8jn8NS3i2dJ7_B2Qyx9v-Dq3MQ9mP8HNL30UWsqY=@protonmail.com> <864j946kbe.fsf@gnu.org> <3hUiHuwpNB-2QtvUKSxx3e3-ZUX_xSI4WMW-BDSuybaKMQ3WTjpI2oVBe4Xato-h8bE-d24VQq9I8tE4x-G1-wyKuBD8cGkwaFggC91ndNM=@protonmail.com> Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="18862"; 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 08:11:24 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 1sPydo-0004iY-Hz for ged-emacs-devel@m.gmane-mx.org; Sat, 06 Jul 2024 08:11:24 +0200 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sPydD-0003to-Ga; Sat, 06 Jul 2024 02:10:47 -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 1sPydB-0003tf-Tq for emacs-devel@gnu.org; Sat, 06 Jul 2024 02:10:45 -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 1sPydB-0003xq-Ad; Sat, 06 Jul 2024 02:10:45 -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=GTiqcM5Y3q6UfqiFUvgEG4pj0YolI/Owj2LFQhww0HM=; b=EIdmenZapd4+ I1KbVEGjUpXrmMVj6QL1FuNO4qtcEoqUSydLGZh+Clj9F+LY5a+X29eGBB08+eeaCmx6GayLllvI7 /OOKBzksmhqW0uNijvIhn63csCIsmcaddD5v1Q+CGBwf/5L95DPYLd3YgEncg/VIyBrmmW8xeU1pu LoEsIcpxo4Wf2DiMD4tqOHF1sOR0aB3hS/9feJwEWS6DbAcjKF1MLqt/a8AoaLZT1nMVmXel7yE/T GvHTWVzAtRA0ChBoyBkQJi4Jvcz0eMJ58PP7sxHDakA77Cok98xJ3cBNECKem3ciJP+86ybATqPfr RnDKmDz1nq1JwoKOjzf28w==; In-Reply-To: <3hUiHuwpNB-2QtvUKSxx3e3-ZUX_xSI4WMW-BDSuybaKMQ3WTjpI2oVBe4Xato-h8bE-d24VQq9I8tE4x-G1-wyKuBD8cGkwaFggC91ndNM=@protonmail.com> (message from Pip Cet on Fri, 05 Jul 2024 20:35:34 +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:321406 Archived-At: > Date: Fri, 05 Jul 2024 20:35:34 +0000 > From: Pip Cet > Cc: gerd.moellmann@gmail.com, eller.helmut@gmail.com, emacs-devel@gnu.org > > > > At least we've excluded WIDE_EMACS_INT :-) > > Which is a pity, IMNSHO, and a major disappointment for me personally, > > since I'm a happy user of that configuration for many years. > > Interesting. It's not too hard to fit a 62-bit integer into two 32-bit integers which are not 4-bit aligned, of course. I'm not sure what else would go wrong though :-) The problem, AFAIU, is the MPS assumption that Lisp objects can fit into a "word", which in their parlance means integral data type whose width is the same as a pointer's. And that is false in WIDE_EMACS_INT builds, because Lisp objects are 64-bit wide, whereas pointers are still 32-bit.