From owner-freebsd-current@FreeBSD.ORG Fri Nov 28 20:59:05 2014 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 91F04907 for ; Fri, 28 Nov 2014 20:59:05 +0000 (UTC) Received: from mail-wg0-x235.google.com (mail-wg0-x235.google.com [IPv6:2a00:1450:400c:c00::235]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 217FE17F for ; Fri, 28 Nov 2014 20:59:05 +0000 (UTC) Received: by mail-wg0-f53.google.com with SMTP id l18so9513481wgh.26 for ; Fri, 28 Nov 2014 12:59:03 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date:message-id:subject :from:to:cc:content-type; bh=XC59kf4eWvaE3h0dHBUhQaOpRtRYUWbkU9F1hwXFseo=; b=iC+UVRdCCx4JPAUZmA33ODS9wGIOkmgKVOvw8zc9sA+odAVo5HYoqzB81cxq6uRapl 1WUXD1XmOPhi2El7Kh8gcDToSmHhqERa+m1l6+8sPlWxKkk3YCtGs3VF1Mhqw6zNYMn7 EEn1p9lOC4MElvRE/0WJcucru7fXhfx42v0tlwmbjenGUY7FRrurjhOXX2172Fas+Fy3 SMO3NWBzStSCgPY9js63xUR/exno+o96N4mdngTZLD60hiRbCWKLxzDQ380Y+R+KNfyR LCMM6CLRJJXIBDi9dXhy2CO5unft6E8cyIf0ZHlkWZ7PMUa/B2YGq4GiqEc2VCZEOYfP JD2g== MIME-Version: 1.0 X-Received: by 10.180.99.105 with SMTP id ep9mr64146868wib.26.1417208343146; Fri, 28 Nov 2014 12:59:03 -0800 (PST) Sender: adrian.chadd@gmail.com Received: by 10.216.106.136 with HTTP; Fri, 28 Nov 2014 12:59:03 -0800 (PST) In-Reply-To: <20141128190721.GA71860@troutmask.apl.washington.edu> References: <20141128183416.GA71749@troutmask.apl.washington.edu> <20141128190721.GA71860@troutmask.apl.washington.edu> Date: Fri, 28 Nov 2014 12:59:03 -0800 X-Google-Sender-Auth: jjtmvIz1fbVOuzFpANFGcDJmYs4 Message-ID: Subject: Re: Possible bug in softfloat From: Adrian Chadd To: Steve Kargl Content-Type: text/plain; charset=UTF-8 Cc: freebsd-current X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 28 Nov 2014 20:59:05 -0000 You can easily fire up a mips32 / mips64 emulator build - cross-build a world+kernel, build an image, then run qemu-devel to boot it. https://wiki.freebsd.org/FreeBSD/MipsEmulation You should be able to get a 32 bit soft-float mips environment inside there which you can use to trigger it. (And also run whatever other floating point validation suite you may hvae.) -adrian On 28 November 2014 at 11:07, Steve Kargl wrote: > On Fri, Nov 28, 2014 at 10:54:25AM -0800, Adrian Chadd wrote: >> On 28 November 2014 at 10:34, Steve Kargl >> wrote: >> > In a thread on comp.lang.c, it was pointed out that softfloat >> > has a bug and in checking src/lib/libc/softfloat I confimed >> > the issue is present in FreeBSD. What I hae not confirmed >> > is whether or not it is possible to hit this bug. In fact, >> > it may only hit arm and mips. Anyway, here's the patch >> >> So we should just commit this? >> > > I suspect the answer is yes, but I have no idea on how > to trigger this code path. I also have no access to > arm or mips hardware where the problem may manifest only. > > It may also be appropriate to have someone else confirm > that the patch is indeed correct. > > -- > steve