From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <tkoenig@netcologne.de>
Received: from cc-smtpout2.netcologne.de (cc-smtpout2.netcologne.de
 [89.1.8.212]) by sourceware.org (Postfix) with ESMTPS id 0B5A33848011
 for <fortran@gcc.gnu.org>; Thu, 18 Mar 2021 18:16:20 +0000 (GMT)
DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 0B5A33848011
Received: from cc-smtpin1.netcologne.de (cc-smtpin1.netcologne.de [89.1.8.201])
 by cc-smtpout2.netcologne.de (Postfix) with ESMTP id CFC1112552;
 Thu, 18 Mar 2021 19:16:17 +0100 (CET)
Received: from localhost (localhost [127.0.0.1])
 by cc-smtpin1.netcologne.de (Postfix) with ESMTP id CB93511E38;
 Thu, 18 Mar 2021 19:16:17 +0100 (CET)
Received: from [2001:4dd6:22d3:0:d9ee:f94a:6429:461d]
 (helo=cc-smtpin1.netcologne.de)
 by localhost with ESMTP (eXpurgate 4.19.0)
 (envelope-from <tkoenig@netcologne.de>)
 id 605398f1-7ac5-7f0000012729-7f000001d0a6-1
 for <multiple-recipients>; Thu, 18 Mar 2021 19:16:17 +0100
Received: from linux-p51k.fritz.box
 (2001-4dd6-22d3-0-d9ee-f94a-6429-461d.ipv6dyn.netcologne.de
 [IPv6:2001:4dd6:22d3:0:d9ee:f94a:6429:461d])
 (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)
 key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256)
 (No client certificate requested)
 by cc-smtpin1.netcologne.de (Postfix) with ESMTPSA;
 Thu, 18 Mar 2021 19:16:13 +0100 (CET)
Subject: Re: MATMUL broken with frontend optimization.
To: Steve Kargl <sgk@troutmask.apl.washington.edu>,
 Richard Biener <richard.guenther@gmail.com>
Cc: Tobias Burnus <tobias@codesourcery.com>,
 "fortran@gcc.gnu.org" <fortran@gcc.gnu.org>
References: <20210318074849.GA22541@troutmask.apl.washington.edu>
 <CAFiYyc3kfoKsqhn2zJWsMzqOZ3-Z3OYoORcJC9mJtpt=Ogm3Vg@mail.gmail.com>
 <563cee48-fbcc-09bc-0cd1-f05082e4feb3@codesourcery.com>
 <CAFiYyc3GzyKqRNLEvf-KA+cgpzXXmYGTwWWVCXWeK50hNFzZkA@mail.gmail.com>
 <20210318161347.GA24201@troutmask.apl.washington.edu>
From: Thomas Koenig <tkoenig@netcologne.de>
Message-ID: <1780c473-3523-316f-c372-52824d062a01@netcologne.de>
Date: Thu, 18 Mar 2021 19:16:13 +0100
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101
 Thunderbird/78.7.0
MIME-Version: 1.0
In-Reply-To: <20210318161347.GA24201@troutmask.apl.washington.edu>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: de-DE
Content-Transfer-Encoding: 7bit
X-Spam-Status: No, score=-3.8 required=5.0 tests=BAYES_00, DKIM_SIGNED,
 DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, NICE_REPLY_A, RCVD_IN_DNSWL_LOW,
 RCVD_IN_MSPIKE_H3, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_PASS,
 TXREP autolearn=ham autolearn_force=no version=3.4.2
X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on
 server2.sourceware.org
X-BeenThere: fortran@gcc.gnu.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Fortran mailing list <fortran.gcc.gnu.org>
List-Unsubscribe: <https://gcc.gnu.org/mailman/options/fortran>,
 <mailto:fortran-request@gcc.gnu.org?subject=unsubscribe>
List-Archive: <https://gcc.gnu.org/pipermail/fortran/>
List-Help: <mailto:fortran-request@gcc.gnu.org?subject=help>
List-Subscribe: <https://gcc.gnu.org/mailman/listinfo/fortran>,
 <mailto:fortran-request@gcc.gnu.org?subject=subscribe>
X-List-Received-Date: Thu, 18 Mar 2021 18:16:21 -0000

OK, so I've had a bit of time to look at the actual test case.  I
missed one very important detail before:  This is a vector-matrix
operation.

For this, we do not have a good library routine (Harald just
removed it because of a bug in buffering), and -fexternal-blas
does not work because we do not handle calls to anything but
*GEMM.

The idea is that, for a vector-matrix-multiplication, the
compiler should have enough information about the information