From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 24408 invoked by alias); 16 Feb 2006 14:11:47 -0000 Received: (qmail 24395 invoked by uid 22791); 16 Feb 2006 14:11:46 -0000 X-Spam-Check-By: sourceware.org Received: from sunsite.ms.mff.cuni.cz (HELO sunsite.mff.cuni.cz) (195.113.15.26) by sourceware.org (qpsmtpd/0.31) with ESMTP; Thu, 16 Feb 2006 14:11:41 +0000 Received: from sunsite.mff.cuni.cz (sunsite.mff.cuni.cz [127.0.0.1]) by sunsite.mff.cuni.cz (8.13.1/8.13.1) with ESMTP id k1GEBdxi029828; Thu, 16 Feb 2006 15:11:39 +0100 Received: (from jj@localhost) by sunsite.mff.cuni.cz (8.13.1/8.13.1/Submit) id k1GEBdga029827; Thu, 16 Feb 2006 15:11:39 +0100 Date: Thu, 16 Feb 2006 14:11:00 -0000 From: Jakub Jelinek To: Francois-Xavier Coudert Cc: Richard Guenther , gfortran , GCC Development Subject: Re: gfortran and -mlong-double-128 Message-ID: <20060216141138.GO4625@sunsite.mff.cuni.cz> Reply-To: Jakub Jelinek References: <19c433eb0602160309y754cf258kd00227b6d80bff2b@mail.gmail.com> <84fc9c000602160450i10b7370aqcec3d373feb1cb64@mail.gmail.com> <19c433eb0602160457u3e82a90cme7ca7c60e18c0083@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <19c433eb0602160457u3e82a90cme7ca7c60e18c0083@mail.gmail.com> User-Agent: Mutt/1.4.1i Mailing-List: contact gcc-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Archive: List-Post: List-Help: Sender: gcc-owner@gcc.gnu.org X-SW-Source: 2006-02/txt/msg00300.txt.bz2 On Thu, Feb 16, 2006 at 01:57:39PM +0100, Fran?ois-Xavier Coudert wrote: > > I guess libgfortran has configury to figure out if kind=16 is available? > > Yes. > > > If so then libgfortran should be built with -mlong-double-128, as this > > should only add extra symbols that do not conflict with kind=4 and kind=8 > > ones. > > Hum, that has to be done early in the configury (before all > autodetection). Do you think it's better suited at the beginning of > libgfortran/configure.ac (a special test, to see if -mlong-double-128 > is available, and if it is add it to CFLAGS), or should it be done in > an upper level (and here is the limit of my understanding of the build > mechanism)? That will not work. It is not enough if GCC supports -mlong-double-128 switch, you also need runtime library support for that. So the check needs to be something like http://gcc.gnu.org/ml/gcc-patches/2006-02/msg01075.html (still not reviewed :( ). If you configure gcc with --with-long-double-128 (what I'm using e.g. on redhat/gcc-4_1-branch now for {ppc*,s390*,sparc,alpha}-*-linux*), then libgfortran is automatically built with -mlong-double-128 and can cope with both -mlong-double-128 and -mlong-double-64 code. libstdc++.so will only support both -mlong-double-{64,128} if it is built with -mlong-double-128, so it is in the same boat as libgfortran. Not sure if it makes any sense to detect the presence of glibc 2.4+ and build libstdc++-v3/libgfortran with -mlong-double-128 even if configured with --without-long-double-128. Jakub