From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1NXxKf-0004RK-SL for qemu-devel@nongnu.org; Thu, 21 Jan 2010 08:44:21 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1NXxKa-0004PF-52 for qemu-devel@nongnu.org; Thu, 21 Jan 2010 08:44:20 -0500 Received: from [199.232.76.173] (port=48185 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NXxKZ-0004P8-Sq for qemu-devel@nongnu.org; Thu, 21 Jan 2010 08:44:15 -0500 Received: from mail-bw0-f212.google.com ([209.85.218.212]:54219) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1NXxKZ-0006OR-DG for qemu-devel@nongnu.org; Thu, 21 Jan 2010 08:44:15 -0500 Received: by bwz4 with SMTP id 4so5157800bwz.22 for ; Thu, 21 Jan 2010 05:44:14 -0800 (PST) MIME-Version: 1.0 Date: Thu, 21 Jan 2010 14:44:14 +0100 Message-ID: <580678e21001210544q40a5c2b7gfcb13cf7576c3e68@mail.gmail.com> From: =?ISO-8859-1?Q?Andr=E9_Bergner?= Content-Type: multipart/alternative; boundary=00032555e42e0f6d7a047dace66b Subject: [Qemu-devel] Bug ARM NEON instrucion vcvt List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org --00032555e42e0f6d7a047dace66b Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Hi, I don't know if this is already known. I found the ARM NEON vcvt instructio= n mentioned in some fix in the mailing list archive, but not what has been fixed. However, I found a bug in the implementation of that instruction. I observe that the type operands are emulated in the wrong order. Example: "vcvt.s32.f32 q0,q0" should convert a float in q0 into an integer= , which works correctly on the CPU. With Qemu I have to change the order of the operands to get the correct result (i.e. "vcvt.f32.s32 q0,q0"). I did not test all combinations of conversions, just integer and float. cheers, Andr=E9 --00032555e42e0f6d7a047dace66b Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable
Hi,

I don't know if this is already k= nown. I found the ARM NEON vcvt instruction mentioned in some fix in the ma= iling list archive, but not what has been fixed.

However, I found a bug in the implementation of that instruction. I observe= that the type operands are emulated in the wrong order.
Example:= "vcvt.s32.f32 =A0q0,q0" should convert a float in q0 into an int= eger, which works correctly on the CPU. With Qemu I have to change the orde= r of the
operands to get the correct result (i.e. "vcvt.f32.s32 =A0q0,q0&q= uot;).
I did not test all combinations of conversions, just integ= er and float.

cheers,
Andr=E9

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