From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265041AbUG2TWS (ORCPT ); Thu, 29 Jul 2004 15:22:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264973AbUG2TV4 (ORCPT ); Thu, 29 Jul 2004 15:21:56 -0400 Received: from embeddededge.com ([209.113.146.155]:24589 "EHLO penguin.netx4.com") by vger.kernel.org with ESMTP id S265041AbUG2TVZ (ORCPT ); Thu, 29 Jul 2004 15:21:25 -0400 In-Reply-To: <85C49799-E168-11D8-B0AC-000393DBC2E8@freescale.com> References: <4108F845.7080305@timesys.com> <85C49799-E168-11D8-B0AC-000393DBC2E8@freescale.com> Mime-Version: 1.0 (Apple Message framework v618) Content-Type: text/plain; charset=US-ASCII; format=flowed Message-Id: Content-Transfer-Encoding: 7bit Cc: LKML , Greg Weeks , LinuxPPC-dev Development From: Dan Malek Subject: Re: [BUG] PPC math-emu multiply problem Date: Thu, 29 Jul 2004 15:22:33 -0400 To: Kumar Gala X-Mailer: Apple Mail (2.618) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Jul 29, 2004, at 10:06 AM, Kumar Gala wrote: > > On Jul 29, 2004, at 8:14 AM, Greg Weeks wrote: > >> I'm seeing what appears to be a bug in the ppc kernel trap math >> emulator. An extreme case for multiplies isn't working the way gcc >> soft-float or hardware floating point is. I'm not surprised. I lifted this code from Sparc, glibc, and adapted it as best I could for PPC years ago for the 8xx. I was happy when it appeared to work for the general cases. :-) Due to its overhead, I never expected it to be _the_ solution for processors that don't have floating point hardware. Recompiling the libraries with soft-float and using that option when compiling is the way to go. Remember, don't mix soft-float compilation with libraries compiled with HW floating point, and trap emulations. They are not compatible and will return erroneous results. Thanks. -- Dan