From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44752) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WzXn4-00087w-GX for qemu-devel@nongnu.org; Tue, 24 Jun 2014 16:58:15 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WzXmv-0004Xi-E5 for qemu-devel@nongnu.org; Tue, 24 Jun 2014 16:58:06 -0400 Received: from mail-qa0-x22d.google.com ([2607:f8b0:400d:c00::22d]:48973) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WzXmv-0004Xe-AB for qemu-devel@nongnu.org; Tue, 24 Jun 2014 16:57:57 -0400 Received: by mail-qa0-f45.google.com with SMTP id v10so754559qac.18 for ; Tue, 24 Jun 2014 13:57:56 -0700 (PDT) Sender: Richard Henderson Message-ID: <53A9E650.2020709@twiddle.net> Date: Tue, 24 Jun 2014 13:57:52 -0700 From: Richard Henderson MIME-Version: 1.0 References: <20140624043423.GX18016@ZenIV.linux.org.uk> <20140624165244.GY18016@ZenIV.linux.org.uk> <53A9C47C.2050002@twiddle.net> <20140624203244.GZ18016@ZenIV.linux.org.uk> In-Reply-To: <20140624203244.GZ18016@ZenIV.linux.org.uk> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [RFC] alpha qemu arithmetic exceptions List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Al Viro Cc: qemu-devel@nongnu.org On 06/24/2014 01:32 PM, Al Viro wrote: > If you have any ideas for testing, I do have working hw (the box that is > currently alive is ev45, though; I _can_ try to boot a UP1000 one, but > I make no promises regarding its fans, both in PSU and in CPU module ;-/) Ah. Gotta be careful with ev4/45... half of the fpu is unimplemented, and so if you're not careful all you're testing is the kernel emulation behaviour. > Um? No, I mean having gen_fp_exc_raise() generate a call of one of the 8 > helpers; gen_ieee_arith3() and friends would remain as-is. It's just that > instead of generating load to exc, andi, call of helper_fp_exc_raise_s or > call of helper_fp_exc_raise we would generate a call of one of the > helper_fp_exc_raise{,_u,_v,_s,_su,_sui,_sv,_svi} and let that sucker deal > with loading exc, updating ->fpcr_exc_status and generating traps. Ah, I getcha. Yes, that makes sense. >>> Another thing: shouldn't arithmetics on denorms without /S raise EXC_M_INV, >>> rather than EXC_M_UNF? >> >> No idea. Should they? > > They seem to - both from the arch.manual and from direct experiment... And > they do set FPCR.INV at the same time, not just trigger the trap. Ok. I'll try to make time to fix up some of this stuff this weekend. r~