From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=53856 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1PpMED-00024I-9k for qemu-devel@nongnu.org; Tue, 15 Feb 2011 09:50:11 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1PpME5-0004CY-5u for qemu-devel@nongnu.org; Tue, 15 Feb 2011 09:50:08 -0500 Received: from eu1sys200aog101.obsmtp.com ([207.126.144.111]:43842) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1PpME4-00048I-1r for qemu-devel@nongnu.org; Tue, 15 Feb 2011 09:50:00 -0500 Message-ID: <4D5A9294.1020606@st.com> Date: Tue, 15 Feb 2011 15:49:56 +0100 From: Christophe Lyon MIME-Version: 1.0 Subject: Re: [Qemu-devel] [PATCH v3 0/6] target-arm: Fix Neon shift instructions. References: <1297437062-6118-1-git-send-email-christophe.lyon@st.com> <4D5A87CF.3090705@st.com> In-Reply-To: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Maydell Cc: "qemu-devel@nongnu.org" On 15.02.2011 15:21, Peter Maydell wrote: > On 15 February 2011 14:03, Christophe Lyon wrote: >> It also seems that the neon_shl_s* helpers don't handle correctly large negative shift amounts. > > They look OK to me (large -ve shift is a huge right shift, > which for signed values should propagate the sign bit > to all bit positions, so we shift-right by typesize - 1), > and I didn't see any problems with them when I was > doing my testing. What do you think they get wrong? > Sorry, you are right. I was confused by comparing with the shifts with rounding. Maybe we should add a few comments in a few places... :-)