From owner-svn-src-all@freebsd.org Mon Sep 26 07:09:23 2016 Return-Path: Delivered-To: svn-src-all@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id A9D73BE96CE for ; Mon, 26 Sep 2016 07:09:23 +0000 (UTC) (envelope-from 0100015765538948-1f7dba54-27b0-4580-9c22-ca89be811a29-000000@amazonses.com) Received: from a8-176.smtp-out.amazonses.com (a8-176.smtp-out.amazonses.com [54.240.8.176]) (using TLSv1 with cipher ECDHE-RSA-AES128-SHA (128/128 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 6F4F4F10 for ; Mon, 26 Sep 2016 07:09:23 +0000 (UTC) (envelope-from 0100015765538948-1f7dba54-27b0-4580-9c22-ca89be811a29-000000@amazonses.com) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/simple; s=vnqrkfnvu6csdl6mwgk5t6ix3nnepx57; d=tarsnap.com; t=1474873756; h=Subject:To:References:Cc:From:Message-ID:Date:MIME-Version:In-Reply-To:Content-Type:Content-Transfer-Encoding; bh=rYLkMkGAKSchJr1lvoRg8oHEHw8BUYq4Irwre1zqmc4=; b=Mu//qWyuAd8jdFeNHZN2pPnQGnG1UHQYMHJ4iVQHPs06k+WoIR6Xs2ceGTrZnNu8 kiCbgJ4EUK4hfzPiBOB/ni+69bIqxXhq5xledaNI5SmcH1+UHHJ+DLe6c6+kx4UH6dc wpWPXoYrDZU07pMGIVAhNN/k04q2/KHyK9APUkSI= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/simple; s=6gbrjpgwjskckoa6a5zn6fwqkn67xbtw; d=amazonses.com; t=1474873756; h=Subject:To:References:Cc:From:Message-ID:Date:MIME-Version:In-Reply-To:Content-Type:Content-Transfer-Encoding:Feedback-ID; bh=rYLkMkGAKSchJr1lvoRg8oHEHw8BUYq4Irwre1zqmc4=; b=ec97ypwZcBp+spHC6/w8II/b8/i7B5yZ7abLD450xX5iYmzLp27mD7Bp3uUXp4ll TUd5oi02I04ggCBgy6mb2UnSLp/SGlSitIz7jv4PVlZzyOpu/6aO1i7WMNc0jiPp5jU sJ9roLRfsQOmC4dLHMl2fEMbEyUVcxpbSwG0ov6s= Subject: Re: svn commit: r306319 - head/sys/i386/i386 To: Bruce Evans References: <201609251839.u8PIdO7t050380@repo.freebsd.org> <0100015762ed107c-206ced2e-2389-462f-afe0-cec7d6c34fb8-000000@email.amazonses.com> <20160926164406.T806@besplex.bde.org> Cc: src-committers@FreeBSD.org, svn-src-all@FreeBSD.org, svn-src-head@FreeBSD.org From: Colin Percival Message-ID: <0100015765538948-1f7dba54-27b0-4580-9c22-ca89be811a29-000000@email.amazonses.com> Date: Mon, 26 Sep 2016 07:09:16 +0000 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:45.0) Gecko/20100101 Thunderbird/45.3.0 MIME-Version: 1.0 In-Reply-To: <20160926164406.T806@besplex.bde.org> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-SES-Outgoing: 2016.09.26-54.240.8.176 Feedback-ID: 1.us-east-1.Lv9FVjaNvvR5llaqfLoOVbo2VxOELl7cjN0AOyXnPlk=:AmazonSES X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 26 Sep 2016 07:09:23 -0000 On 09/25/16 23:53, Bruce Evans wrote: > On Sun, 25 Sep 2016, Colin Percival wrote: >> On 09/25/16 11:39, Bruce Evans wrote: >>> Author: bde >>> Date: Sun Sep 25 18:39:24 2016 >>> New Revision: 306319 >>> URL: https://svnweb.freebsd.org/changeset/base/306319 >>> >>> Log: >>> Minor fixes for 160-bit disassembly: >> >> I thought the x86 architecture was limited to 120-bit instructions? > > Oops. > > Is 120 the exact limit on instruction length is is that just for prefixes? > I think the instruction fetch pipeline was 16 bytes, but it is now often > 32 or 64. Traditionally x86 CPUs would generate an invalid-opcode fault if redundant instruction prefixes resulted in an instruction exceeding 15 bytes. This behaviour might have changed in the past two decades, but I doubt it. -- Colin Percival Security Officer Emeritus, FreeBSD | The power to serve Founder, Tarsnap | www.tarsnap.com | Online backups for the truly paranoid