From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Mattias =?UTF-8?Q?Engdeg=C3=A5rd?= Newsgroups: gmane.emacs.bugs Subject: bug#68244: hash-table improvements Date: Thu, 4 Jan 2024 18:02:08 +0100 Message-ID: <4FC7642E-BAAF-40E3-AADC-0485AB085D6D@gmail.com> References: <83r0ixvys9.fsf@gnu.org> Mime-Version: 1.0 (Mac OS X Mail 14.0 \(3654.120.0.1.15\)) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="24444"; mail-complaints-to="usenet@ciao.gmane.io" Cc: 68244@debbugs.gnu.org, Stefan Monnier To: Eli Zaretskii Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Thu Jan 04 18:03:21 2024 Return-path: Envelope-to: geb-bug-gnu-emacs@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 1rLR7o-00065A-Ed for geb-bug-gnu-emacs@m.gmane-mx.org; Thu, 04 Jan 2024 18:03:20 +0100 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rLR7V-0007BB-NM; Thu, 04 Jan 2024 12:03:01 -0500 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 1rLR7U-0007Aw-8D for bug-gnu-emacs@gnu.org; Thu, 04 Jan 2024 12:03:00 -0500 Original-Received: from debbugs.gnu.org ([2001:470:142:5::43]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1rLR7S-0001dw-SP for bug-gnu-emacs@gnu.org; Thu, 04 Jan 2024 12:02:59 -0500 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1rLR7W-0008RA-9D for bug-gnu-emacs@gnu.org; Thu, 04 Jan 2024 12:03:02 -0500 X-Loop: help-debbugs@gnu.org Resent-From: Mattias =?UTF-8?Q?Engdeg=C3=A5rd?= Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Thu, 04 Jan 2024 17:03:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 68244 X-GNU-PR-Package: emacs Original-Received: via spool by 68244-submit@debbugs.gnu.org id=B68244.170438774632387 (code B ref 68244); Thu, 04 Jan 2024 17:03:02 +0000 Original-Received: (at 68244) by debbugs.gnu.org; 4 Jan 2024 17:02:26 +0000 Original-Received: from localhost ([127.0.0.1]:55574 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1rLR6v-0008QJ-HX for submit@debbugs.gnu.org; Thu, 04 Jan 2024 12:02:25 -0500 Original-Received: from mail-lf1-x135.google.com ([2a00:1450:4864:20::135]:50394) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1rLR6q-0008Q2-5x for 68244@debbugs.gnu.org; Thu, 04 Jan 2024 12:02:24 -0500 Original-Received: by mail-lf1-x135.google.com with SMTP id 2adb3069b0e04-50e7d6565b5so800646e87.0 for <68244@debbugs.gnu.org>; Thu, 04 Jan 2024 09:02:16 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1704387730; x=1704992530; darn=debbugs.gnu.org; h=to:references:message-id:content-transfer-encoding:cc:date :in-reply-to:from:subject:mime-version:sender:from:to:cc:subject :date:message-id:reply-to; bh=dikyA4I3s+509GSbvdV51kXgCPWuevNzCWd1UX66s+k=; b=JjfNvZ9VZmWpU8fjgEIC12TY4tKfHf1U+XoHA0a2VkS75XltAjhFoSRbVgYXiYD90B EBJYsNzQlOQA9q1sWMtgiy3HUQjuaweAqlqkYW+hAOuIccCQcJYNDBfw9nl4es5tl1TP t8VDX8mExFNepig58Vz7zLgfoLYuZ6B/4EmPdYjZhwGU1F+Ufk5TMQWLVncZltSXRK1J r5nluhN14l+XG5j31sGeeosOAi/ySoAdf9oDWCYy8K6YmXdFbhRLVvar3PPTLNp+PnUG LY5U54SJYw6nNxX9ORJnuioUo/Gb6W/0l6FxPorSYwUqA0x6uC1x+SaWMepBskaHCxcv ZZng== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1704387730; x=1704992530; h=to:references:message-id:content-transfer-encoding:cc:date :in-reply-to:from:subject:mime-version:sender:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=dikyA4I3s+509GSbvdV51kXgCPWuevNzCWd1UX66s+k=; b=A1+3CtCxWU6ZfftTmWFRT62rS6xhBbbZ3MnoIti22LSmMSH394MLfgh4M4owjNcoS4 vPm/XK3diZ1DyAzQsiayaoOlrL6LMu7Im8OioOMehSidFt6AKUz/8+ZCCV4FdiB1H/ER JCTxj2Ynva5LmBKn4WHPBdQ5NFRjXp84edcvG8gqzr5GEUQ4zkLsNkZ7GQnmSONAwlqT DZ4vBzC6RVlicFHfsLfMFyeqN99ClTAofmxyIu1Z5kZjAfIWkpo0wdddfjwVRSG2T6EJ TNax7elC8jwLSsFwDTW5+8AFP/3hOwb7Ls4sUFZIqtnJv2znrq3TSrBt8qf3AMrwBjIg WdTA== X-Gm-Message-State: AOJu0YyizBxWin6Te2B9Macxtkk0fZafNwCmW4k4IjSkKZj69EiiTlKz bxiGoG+tnl7FylKLIzc2oj8= X-Google-Smtp-Source: AGHT+IFGFtwmATa+tq86Jf/9xxZtYhm+vQL1jAZaZIHvf4EV4jzRMhYPbDerVwLnTa1zct7FRvZ2+A== X-Received: by 2002:ac2:592f:0:b0:50e:7be3:c706 with SMTP id v15-20020ac2592f000000b0050e7be3c706mr487247lfi.21.1704387729847; Thu, 04 Jan 2024 09:02:09 -0800 (PST) Original-Received: from smtpclient.apple (c80-217-1-132.bredband.tele2.se. [80.217.1.132]) by smtp.gmail.com with ESMTPSA id w15-20020ac2598f000000b0050e8d0c5efdsm2056023lfn.61.2024.01.04.09.02.09 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Thu, 04 Jan 2024 09:02:09 -0800 (PST) In-Reply-To: <83r0ixvys9.fsf@gnu.org> X-Mailer: Apple Mail (2.3654.120.0.1.15) X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.bugs:277318 Archived-At: 4 jan. 2024 kl. 17.39 skrev Eli Zaretskii : > Any data about the actual performance gains? Lots, naturally, but hash tables have many moving parts and performance = is many-dimensional which is why I didn't include the raw data; it's = voluminous and not always easy to interpret. Giving a single number as = in 'now 20 % faster' is impossible if we want to stay honest, because = there are so many different aspects, contexts and operations. The reforms so far actually don't change the basic algorithms or data = structures much but concentrate on slimming the internal and external = representation, both of which are basically guaranteed to provide = performance gains (and they do). External representation improvements means that printing and reading is = substantially faster, especially for small tables (otherwise most of the = time is just spent printing and reading the data), but many tables are = small. Internal representation means that we now use much less memory for the = basic hash table objects and for the tables, and even more importantly = avoid expensive GC involvement where not absolutely necessary. This = gives some measurable speed-up itself, but provides benefits for other = code. I do want to change some of the hashing and range reduction code, = though, but this requires even more careful benchmarking to be sure that = we don't end up with any surprises.