From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Paul Eggert Newsgroups: gmane.emacs.devel Subject: Re: master 669aeaf: Prefer make_nil_vector to make-vector with nil Date: Tue, 11 Aug 2020 17:01:41 -0700 Organization: UCLA Computer Science Department Message-ID: <670f5411-9c55-5ee4-d27d-5c3df7022d29@cs.ucla.edu> References: <20200811173009.24292.8963@vcs0.savannah.gnu.org> <20200811173011.46A2E20CB8@vcs0.savannah.gnu.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="2004"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 Cc: emacs-devel@gnu.org To: Pip Cet Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Wed Aug 12 02:03:59 2020 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 1k5eFK-0000O1-P4 for ged-emacs-devel@m.gmane-mx.org; Wed, 12 Aug 2020 02:03:58 +0200 Original-Received: from localhost ([::1]:52276 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1k5eFJ-000176-PX for ged-emacs-devel@m.gmane-mx.org; Tue, 11 Aug 2020 20:03:57 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:50562) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1k5eDD-0008L4-HB for emacs-devel@gnu.org; Tue, 11 Aug 2020 20:01:47 -0400 Original-Received: from zimbra.cs.ucla.edu ([131.179.128.68]:35264) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1k5eDA-00036m-SI for emacs-devel@gnu.org; Tue, 11 Aug 2020 20:01:46 -0400 Original-Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id 5389C1600FC; Tue, 11 Aug 2020 17:01:42 -0700 (PDT) Original-Received: from zimbra.cs.ucla.edu ([127.0.0.1]) by localhost (zimbra.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id O3D6sLeI6qEF; Tue, 11 Aug 2020 17:01:41 -0700 (PDT) Original-Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id 8BE6B1600ED; Tue, 11 Aug 2020 17:01:41 -0700 (PDT) X-Virus-Scanned: amavisd-new at zimbra.cs.ucla.edu Original-Received: from zimbra.cs.ucla.edu ([127.0.0.1]) by localhost (zimbra.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id uxX2_VhtkoUa; Tue, 11 Aug 2020 17:01:41 -0700 (PDT) Original-Received: from [192.168.1.9] (cpe-75-82-69-226.socal.res.rr.com [75.82.69.226]) by zimbra.cs.ucla.edu (Postfix) with ESMTPSA id 644EA1600FC; Tue, 11 Aug 2020 17:01:41 -0700 (PDT) Autocrypt: addr=eggert@cs.ucla.edu; prefer-encrypt=mutual; keydata= LS0tLS1CRUdJTiBQR1AgUFVCTElDIEtFWSBCTE9DSy0tLS0tCgptUUlOQkV5QWNtUUJFQURB QXlIMnhvVHU3cHBHNUQzYThGTVpFb243NGRDdmM0K3ExWEEySjJ0QnkycHdhVHFmCmhweHhk R0E5Smo1MFVKM1BENGJTVUVnTjh0TFowc2FuNDdsNVhUQUZMaTI0NTZjaVNsNW04c0thSGxH ZHQ5WG0KQUF0bVhxZVpWSVlYL1VGUzk2ZkR6ZjR4aEVtbS95N0xiWUVQUWRVZHh1NDd4QTVL aFRZcDVibHRGM1dZRHoxWQpnZDdneDA3QXV3cDdpdzdlTnZub0RUQWxLQWw4S1lEWnpiRE5D UUdFYnBZM2VmWkl2UGRlSStGV1FONFcra2doCnkrUDZhdTZQcklJaFlyYWV1YTdYRGRiMkxT MWVuM1NzbUUzUWpxZlJxSS9BMnVlOEpNd3N2WGUvV0szOEV6czYKeDc0aVRhcUkzQUZINmls QWhEcXBNbmQvbXNTRVNORnQ3NkRpTzFaS1FNcjlhbVZQa25qZlBtSklTcWRoZ0IxRApsRWR3 MzRzUk9mNlY4bVp3MHhmcVQ2UEtFNDZMY0ZlZnpzMGtiZzRHT1JmOHZqRzJTZjF0azVlVThN Qml5Ti9iClowM2JLTmpOWU1wT0REUVF3dVA4NGtZTGtYMndCeHhNQWhCeHdiRFZadWR6eERa SjFDMlZYdWpDT0pWeHEya2wKakJNOUVUWXVVR3FkNzVBVzJMWHJMdzYrTXVJc0hGQVlBZ1Jy NytLY3dEZ0JBZndoU In-Reply-To: Content-Language: en-US Received-SPF: pass client-ip=131.179.128.68; envelope-from=eggert@cs.ucla.edu; helo=zimbra.cs.ucla.edu X-detected-operating-system: by eggs.gnu.org: First seen = 2020/08/11 19:43:19 X-ACL-Warn: Detected OS = Linux 3.1-3.10 X-Spam_score_int: -41 X-Spam_score: -4.2 X-Spam_bar: ---- X-Spam_report: (-4.2 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.23 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" Xref: news.gmane.io gmane.emacs.devel:253650 Archived-At: On 8/11/20 11:31 AM, Pip Cet wrote: > How is it faster? It calls allocate_nil_vector, which calls > allocate_clear_vector. make_vector also calls allocate_clear_vector. Oh, you're right, I forgot about the runtime test in make_vector that causes it to do what make_nil_vector would do if the initializer is nil. > I'd say we cut down the complication and use > Fmake_vector almost everywhere Although we could simplify somewhat, using Fmake_vector everywhere would go too far. It's useful to know one needn't worry about invalid args when calling the proper make-vector variant. I found this useful when checking Emacs for undefined behavior on integer overflow; for example, 'Fmake_vector (make_fixnum (n), ...)' won't do if n is out of range for fixnum. And an uninitialized variant is also worthwhile, to avoid initializing vectors twice.