From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:33013)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <richard.henderson@linaro.org>) id 1f9DQS-0007iF-4K
	for qemu-devel@nongnu.org; Thu, 19 Apr 2018 13:32:53 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <richard.henderson@linaro.org>) id 1f9DQO-00072y-43
	for qemu-devel@nongnu.org; Thu, 19 Apr 2018 13:32:52 -0400
Received: from mail-pf0-x241.google.com ([2607:f8b0:400e:c00::241]:40568)
	by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16)
	(Exim 4.71) (envelope-from <richard.henderson@linaro.org>)
	id 1f9DQN-00072V-UL
	for qemu-devel@nongnu.org; Thu, 19 Apr 2018 13:32:48 -0400
Received: by mail-pf0-x241.google.com with SMTP id y66so2969202pfi.7
	for <qemu-devel@nongnu.org>; Thu, 19 Apr 2018 10:32:47 -0700 (PDT)
References: <20180417221246.14672-1-richard.henderson@linaro.org>
	<CAFEAcA-auT4gVS0boZcFxeNuf-6x4u_wfochb9bqwKmryjtsUA@mail.gmail.com>
From: Richard Henderson <richard.henderson@linaro.org>
Message-ID: <c97f1392-570c-b3a2-1a2f-a223349b965e@linaro.org>
Date: Thu, 19 Apr 2018 07:32:40 -1000
MIME-Version: 1.0
In-Reply-To: <CAFEAcA-auT4gVS0boZcFxeNuf-6x4u_wfochb9bqwKmryjtsUA@mail.gmail.com>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Subject: Re: [Qemu-devel] [PATCH for-2.13] tcg: Allow wider vectors for cmp
 and mul
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel/>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Peter Maydell <peter.maydell@linaro.org>
Cc: QEMU Developers <qemu-devel@nongnu.org>

On 04/19/2018 12:17 AM, Peter Maydell wrote:
> On 17 April 2018 at 23:12, Richard Henderson
> <richard.henderson@linaro.org> wrote:
>> In db432672, we allow wide inputs for operations such as add.
>> However, in 212be173 and 3774030a we didn't do the same for
>> compare and multiply.
>>
>> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> 
> Can we hit these asserts in the uses of tcg_gen_mul_vec
> and tcg_gen_cmp_vec currently in the aarch64 frontend, or
> is this only a problem for the not-yet-landed SVE code?

Only sve code -- it requires a VQ that is not a power of 2, e.g. 3.

> I notice that do_shifti() also has a
>     tcg_debug_assert(at->base_type == type);
> Is that assert correct, or should it also be changed to >= ?

I think that one is correct.  This assert is hit for something like

	mul	z3, z2, z1[0]

where we dup the scalar to our widest host vector width and then multiply.  In
the case of VQ=3, the dup might be to v256, one v256 multiply, and one v128
multiply.


r~