From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp-o-2.desy.de (smtp-o-2.desy.de [IPv6:2001:638:700:1038::1:9b]) by sourceware.org (Postfix) with ESMTPS id 1E97738A9415 for ; Tue, 11 Jan 2022 12:50:09 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 1E97738A9415 Received: from smtp-buf-2.desy.de (smtp-buf-2.desy.de [IPv6:2001:638:700:1038::1:a5]) by smtp-o-2.desy.de (Postfix) with ESMTP id 94A01161237 for ; Tue, 11 Jan 2022 13:50:06 +0100 (CET) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp-o-2.desy.de 94A01161237 Received: from smtp-m-2.desy.de (smtp-m-2.desy.de [IPv6:2001:638:700:1038::1:82]) by smtp-buf-2.desy.de (Postfix) with ESMTP id 8F1161A00AC for ; Tue, 11 Jan 2022 13:50:06 +0100 (CET) X-Virus-Scanned: amavisd-new at desy.de Received: from z-prx-4.desy.de (z-prx-4.desy.de [131.169.10.28]) by smtp-intra-1.desy.de (Postfix) with ESMTP id 70051C0177 for ; Tue, 11 Jan 2022 13:50:06 +0100 (CET) Received: from z-prx-4.desy.de ([127.0.0.1]) by localhost (z-prx-4.desy.de [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id MDSLsAq5_KjV for ; Tue, 11 Jan 2022 13:50:06 +0100 (CET) Received: from smtpclient.apple (cmspcx14975.desy.de [131.169.49.95]) by z-prx-4.desy.de (Postfix) with ESMTPSA id 5BB5AA00B3 for ; Tue, 11 Jan 2022 13:50:06 +0100 (CET) From: Mikel Mendizabal Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Mime-Version: 1.0 (Mac OS X Mail 15.0 \(3693.20.0.1.32\)) Subject: GCC and OpenACC Message-Id: <1935E1B7-16F3-4545-A5A2-4AEE720E5C7A@desy.de> Date: Tue, 11 Jan 2022 13:50:05 +0100 To: gcc@gcc.gnu.org X-Mailer: Apple Mail (2.3693.20.0.1.32) X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: gcc@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 11 Jan 2022 12:50:11 -0000 Dear GCC developers, In the past year we started the offload of our software to GPUs. We = decided to go with OpenACC. The program we are trying to offload is = Millepede2 (MP2), a tracker alignment software used to align the CMS = experiment tracker at the large hadron collider.=20 We are using gcc as our main compiler. However, we found a major = inconvenience with OpenACC 2.6, the REDUCTION clause does not accept = arrays. Thus, it not possible for us to parallelise our largest loops = due to array dependencies. We managed to offload MP2 for small datasets, = we worked around the reduction issue. Nonetheless, if our alignment = campaign is large the workarounds are not useful anymore.=20 I went thought the new versions of OpenACC and I found that v2.7 accepts = arrays for the REDUCTION clause. I was wondering if it is in your plans = to include a newer version of OpenACC for the next releases.=20 Sincerely, Mikel Mendizabal=