From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <segher@kernel.crashing.org>
Received: from gate.crashing.org (gate.crashing.org [63.228.1.57])
 by sourceware.org (Postfix) with ESMTP id 860803857BA1
 for <gcc-patches@gcc.gnu.org>; Thu, 23 Jun 2022 19:07:21 +0000 (GMT)
DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 860803857BA1
Authentication-Results: sourceware.org; dmarc=none (p=none dis=none)
 header.from=kernel.crashing.org
Authentication-Results: sourceware.org;
 spf=pass smtp.mailfrom=kernel.crashing.org
Received: from gate.crashing.org (localhost.localdomain [127.0.0.1])
 by gate.crashing.org (8.14.1/8.14.1) with ESMTP id 25NJ6KgK030905;
 Thu, 23 Jun 2022 14:06:20 -0500
Received: (from segher@localhost)
 by gate.crashing.org (8.14.1/8.14.1/Submit) id 25NJ6Jmb030904;
 Thu, 23 Jun 2022 14:06:19 -0500
X-Authentication-Warning: gate.crashing.org: segher set sender to
 segher@kernel.crashing.org using -f
Date: Thu, 23 Jun 2022 14:06:19 -0500
From: Segher Boessenkool <segher@kernel.crashing.org>
To: "Kewen.Lin" <linkw@linux.ibm.com>
Cc: GCC Patches <gcc-patches@gcc.gnu.org>, David Edelsohn <dje.gcc@gmail.com>, 
 Peter Bergner <bergner@linux.ibm.com>,
 will schmidt <will_schmidt@vnet.ibm.com>
Subject: Re: [PATCH v3] rs6000: Adjust mov optabs for opaque modes [PR103353]
Message-ID: <20220623190619.GU25951@gate.crashing.org>
References: <09c34b29-feea-d26e-2c4f-5e096ab286bc@linux.ibm.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <09c34b29-feea-d26e-2c4f-5e096ab286bc@linux.ibm.com>
User-Agent: Mutt/1.4.2.3i
X-Spam-Status: No, score=-3.2 required=5.0 tests=BAYES_00, JMQ_SPF_NEUTRAL,
 KAM_DMARC_STATUS, SPF_HELO_PASS, SPF_PASS, TXREP,
 T_SCC_BODY_TEXT_LINE autolearn=no autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
 server2.sourceware.org
X-BeenThere: gcc-patches@gcc.gnu.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Gcc-patches mailing list <gcc-patches.gcc.gnu.org>
List-Unsubscribe: <https://gcc.gnu.org/mailman/options/gcc-patches>,
 <mailto:gcc-patches-request@gcc.gnu.org?subject=unsubscribe>
List-Archive: <https://gcc.gnu.org/pipermail/gcc-patches/>
List-Post: <mailto:gcc-patches@gcc.gnu.org>
List-Help: <mailto:gcc-patches-request@gcc.gnu.org?subject=help>
List-Subscribe: <https://gcc.gnu.org/mailman/listinfo/gcc-patches>,
 <mailto:gcc-patches-request@gcc.gnu.org?subject=subscribe>
X-List-Received-Date: Thu, 23 Jun 2022 19:07:23 -0000

Hi!

On Wed, May 18, 2022 at 10:07:48PM +0800, Kewen.Lin wrote:
> As PR103353 shows, we may want to continue to expand a MMA built-in
> function like a normal function, even if we have already emitted
> error messages about some missing required conditions.  As shown in
> that PR, without one explicit mov optab on OOmode provided, it would
> call emit_move_insn recursively.

First off: lxvp is a VSX insn, not an MMA insn.  So please don't call it
that -- this confusion is what presumably caused the problem here, so it
would be good to root it out :-)

> +  /* Opaque modes are only expected to be available when MMA is supported,

Why do people expect that?  It is completely wrong.  The name "opaque"
itself already says this is not just for MMA, but perhaps more
importantly, it is a basic VSX insn, doesn't touch any MMA resources,
and is useful in other contexts as well.

So this needs some bigger surgery.


Segher