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: Time to merge scratch/correct-warning-pos into master, perhaps? Date: Mon, 21 Feb 2022 05:29:08 +0200 Message-ID: <834k4sx5h7.fsf@gnu.org> References: <83v8xt20db.fsf@gnu.org> <83ee4gyzrh.fsf@gnu.org> <83v8xryh4d.fsf@gnu.org> <831qzyzt5t.fsf@gnu.org> <874k4u92gp.fsf@randomsample> Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="1234"; mail-complaints-to="usenet@ciao.gmane.io" Cc: deng@randomsample.de, mattiase@acm.org, emacs-devel@gnu.org, gregory@heytings.org, acm@muc.de, larsi@gnus.org To: Stefan Monnier Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Mon Feb 21 04:30:04 2022 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 1nLzOm-00009m-CU for ged-emacs-devel@m.gmane-mx.org; Mon, 21 Feb 2022 04:30:04 +0100 Original-Received: from localhost ([::1]:42906 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nLzOk-0004Z5-Qq for ged-emacs-devel@m.gmane-mx.org; Sun, 20 Feb 2022 22:30:02 -0500 Original-Received: from eggs.gnu.org ([209.51.188.92]:32856) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nLzNr-0003tJ-QG for emacs-devel@gnu.org; Sun, 20 Feb 2022 22:29:07 -0500 Original-Received: from [2001:470:142:3::e] (port=39362 helo=fencepost.gnu.org) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nLzNp-0001IO-PX; Sun, 20 Feb 2022 22:29:05 -0500 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=aepJKSXS5ZX+26nf3VNfULLe0WUMOJ8FqZ1iAYFMjXk=; b=kaQTGAKklzxR 22pXyUUlzIGO4gvE1sE4zvtSaMDKy46oNSpaNa7M0oBezME3ZblbXmS+i12/UswEyV91M8NQ5B9Pk tC96ITIbhxz0W2NlX3pyzZF5hTIIYy1s0dC/Rx6K6FF2M9Ny4mTGUppe0WCIDQJSVdyBUige35ioY FJnW5THvtxticfycZRIiieWkRyiCzzYH206t5N5Ey0lb8Im/o1mbC27wIOORSssrDi75NNnITq4lV cHVH4lmfLdWUVhDZMv8iGGyELqAlhDsJYr+wL33eRW32+AsI49pHE8m/Ixm6hpkf/QT6o5vCE+UK+ 1befdDqPG6ic9iu2bbwAuQ==; Original-Received: from [87.69.77.57] (port=2408 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nLzNp-0006qS-9I; Sun, 20 Feb 2022 22:29:05 -0500 In-Reply-To: (message from Stefan Monnier on Sun, 20 Feb 2022 18:02:01 -0500) 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" Xref: news.gmane.io gmane.emacs.devel:286542 Archived-At: > From: Stefan Monnier > Cc: David Engster , Eli Zaretskii , > larsi@gnus.org, mattiase@acm.org, gregory@heytings.org, > emacs-devel@gnu.org > Date: Sun, 20 Feb 2022 18:02:01 -0500 > > > I think I'm just trying to get some sort of handle on how much the code > > has slowed down because of EQ. Obviously, making EQ into a function > > (rather than an inline function) will have distorted things, but it > > seems the easiest way of measuring something at the moment. > > I understand, but it's still going to be hard to figure out what the > result means. Let's say you find that the new non-inlined EQ is 20% > slower than the old non-inlined EQ, what does it tell us about the > inlined versions? That they are ~20% slower. Moreover, it hopefully will tell us which part(s) of EQ are more expensive, and thus allow to try making it faster. > It's quite possible that more than 50% of the time spent in the > non-inlined EQ is spent in the "function call overhead" (the jumps > themselves, the forced placement into specific registers, the need to > reify a condition code into a boolean stored in a register, the > impossibility to move code around the call to EQ because the compiler > doesn't know it's a pure function, ...)? That time should be the same in the old and the new EQ.