From owner-freebsd-hackers@FreeBSD.ORG Tue Feb 22 00:10:35 2011 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id A240F106564A for ; Tue, 22 Feb 2011 00:10:35 +0000 (UTC) (envelope-from yuri@rawbw.com) Received: from shell0.rawbw.com (shell0.rawbw.com [198.144.192.45]) by mx1.freebsd.org (Postfix) with ESMTP id 8CF218FC0C for ; Tue, 22 Feb 2011 00:10:35 +0000 (UTC) Received: from eagle.yuri.org (stunnel@localhost [127.0.0.1]) (authenticated bits=0) by shell0.rawbw.com (8.14.4/8.14.4) with ESMTP id p1M07hFK059148 for ; Mon, 21 Feb 2011 16:07:44 -0800 (PST) (envelope-from yuri@rawbw.com) Message-ID: <4D62FEFB.1070709@rawbw.com> Date: Mon, 21 Feb 2011 16:10:35 -0800 From: Yuri User-Agent: Mozilla/5.0 (X11; U; FreeBSD amd64; en-US; rv:1.9.1.16) Gecko/20101211 Thunderbird/3.0.11 MIME-Version: 1.0 To: freebsd-hackers@freebsd.org References: <4D62F267.3000706@rawbw.com> <20110221233817.GA4792@britannica.bec.de> In-Reply-To: <20110221233817.GA4792@britannica.bec.de> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: FreeBSD ABI? X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 22 Feb 2011 00:10:35 -0000 On 02/21/2011 15:38, Joerg Sonnenberger wrote: > That's a major difference. The Linux people decided a while ago that > stack alignment should be 16 Byte. GCC effectively forces that down > everyone's throat because until at least GCC 4.2 or 4.3, it can't > correctly realign the stack and just fails miserable. I would be > surprised if it was a conscious decision for the Solaris either. > On the other hand, 16 byte alignment allows for some extra optimizations. For example many SIMD instructions like movdqa can only be used on 16 byte aligned values. That's why linux probably decided to change this. Yuri