From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Dmitry Antipov Newsgroups: gmane.emacs.devel Subject: Pure nil and t? Date: Mon, 22 Sep 2014 12:38:16 +0400 Message-ID: <541FDFF8.8060405@yandex.ru> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-Trace: ger.gmane.org 1411375134 7106 80.91.229.3 (22 Sep 2014 08:38:54 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Mon, 22 Sep 2014 08:38:54 +0000 (UTC) To: Emacs development discussions Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Mon Sep 22 10:38:47 2014 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1XVz8w-0005BT-QK for ged-emacs-devel@m.gmane.org; Mon, 22 Sep 2014 10:38:46 +0200 Original-Received: from localhost ([::1]:43492 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XVz8w-0003xW-9a for ged-emacs-devel@m.gmane.org; Mon, 22 Sep 2014 04:38:46 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:49980) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XVz8m-0003wN-Jx for emacs-devel@gnu.org; Mon, 22 Sep 2014 04:38:43 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XVz8Z-0007Os-MW for emacs-devel@gnu.org; Mon, 22 Sep 2014 04:38:36 -0400 Original-Received: from forward2l.mail.yandex.net ([84.201.143.145]:60236) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XVz8Z-0007Mc-A3 for emacs-devel@gnu.org; Mon, 22 Sep 2014 04:38:23 -0400 Original-Received: from smtp14.mail.yandex.net (smtp14.mail.yandex.net [95.108.131.192]) by forward2l.mail.yandex.net (Yandex) with ESMTP id EE1C51AC0F9A for ; Mon, 22 Sep 2014 12:38:16 +0400 (MSK) Original-Received: from smtp14.mail.yandex.net (localhost [127.0.0.1]) by smtp14.mail.yandex.net (Yandex) with ESMTP id B08871B604AD for ; Mon, 22 Sep 2014 12:38:16 +0400 (MSK) Original-Received: from unknown (unknown [37.139.80.10]) by smtp14.mail.yandex.net (nwsmtp/Yandex) with ESMTPSA id WaKzeHxsuu-cGRec0MI; Mon, 22 Sep 2014 12:38:16 +0400 (using TLSv1.2 with cipher AES128-SHA (128/128 bits)) (Client certificate not present) X-Yandex-Uniq: 18bba3c1-fcf3-4d29-9b34-72e1e17e6e85 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yandex.ru; s=mail; t=1411375096; bh=1QP+4z8oFGqhoAd9lNT/yrf8KwNN5v5zu8tnFB0REy8=; h=Message-ID:Date:From:User-Agent:MIME-Version:To:Subject: Content-Type:Content-Transfer-Encoding; b=YVv8/Hj+AJcVg3LVa5fLk4CSfA9y/HRGr+FTh3G0RTi7TSsGaellXeAnoFGHgy8eR ZrQc4TPVqTEcWm2tR/Lu3WC/mo2rH+pQUcOgvQ0Y04kv/dSdbze11XVFDK0/I4YzOI Hg7qqa1dhRCEC6o7c2UarhdA18Dfm0dHv2NftzzY= Authentication-Results: smtp14.mail.yandex.net; dkim=pass header.i=@yandex.ru User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.1.1 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [generic] [fuzzy] X-Received-From: 84.201.143.145 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.14 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.org@gnu.org Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:174639 Archived-At: For a long byte-compile runs, ~15-17% of objects seen by GC are nil and t (especially nil, which is ~10x more "popular" than t). What about making them pure? Thus way they will be quickly filtered out by PURE_POINTER_P check in mark_object, thus offloading GC from an in-depth examination of them each time when they're found. Dmitry