From owner-freebsd-arm@freebsd.org Thu Oct 1 09:24:40 2015 Return-Path: Delivered-To: freebsd-arm@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 E767AA0B775 for ; Thu, 1 Oct 2015 09:24:40 +0000 (UTC) (envelope-from sparvu@kronometrix.org) Received: from mail.kronometrix.org (mail.kronometrix.org [54.72.43.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "mail.kronometrix.org", Issuer "mail.kronometrix.org" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 80B7C1B38 for ; Thu, 1 Oct 2015 09:24:39 +0000 (UTC) (envelope-from sparvu@kronometrix.org) Received: from [192.168.1.171] (188-127-209-196.cust.suomicom.net [188.127.209.196]) (authenticated bits=0) by mail.kronometrix.org (8.14.9/8.14.9) with ESMTP id t919OVcb085046 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NO); Thu, 1 Oct 2015 09:24:31 GMT (envelope-from sparvu@kronometrix.org) Reply-To: sparvu@kronometrix.org Subject: Re: compile kernel with hard float support References: <560CF28F.4000908@kronometrix.org> <20151001101825.44341b74@bender> To: Andrew Turner Cc: "freebsd-arm@freebsd.org" From: Stefan Parvu Organization: kronometrix.org Message-ID: <560CFBCA.5010001@kronometrix.org> Date: Thu, 1 Oct 2015 12:24:26 +0300 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 MIME-Version: 1.0 In-Reply-To: <20151001101825.44341b74@bender> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-arm@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: "Porting FreeBSD to ARM processors." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 01 Oct 2015 09:24:41 -0000 > No, armv6 is built with softfp. This means the compiler is free to use > the VFP, but when passing floating-point data between functions it > needs to copy this to the general-purpose registers. > > Even without this the helper functions detect the presence of the VFP > unit and make use of this when available. right. Got it. Thanks for explanation. > The kernel doesn't use any floating-point hardware, other than to > enable and disable it in the VFP driver. As such it doesn't matter if > you've built the kernel for hard-float or not, it will make no > difference to the code generated. ok, I see. Ok this probable wont make any difference to my case. Right. 10 x thanks. -- Stefan Parvu