From patchwork Thu Mar 10 11:26:38 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tom de Vries X-Patchwork-Id: 51845 Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id CD5F03858000 for ; Thu, 10 Mar 2022 11:29:12 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org CD5F03858000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1646911752; bh=R42e0/44MSqWhSabbJjc2QGdKcPyizW8wy0teqUzUrI=; h=Date:To:Subject:List-Id:List-Unsubscribe:List-Archive:List-Post: List-Help:List-Subscribe:From:Reply-To:From; b=V0cSyCUDNdKR/MZ3rH77Q7h4IoyiFt65PrC3Yd8ZF0UL3vvMzWYmW8TYK09DXnloi xNdN0PPb/NFtEVjvOQJUfwZotz8Cqs2mEh/O8HRghG2iPzO3R2hFf+mALdHlqsgcuk 7GSQMCtzjha/RxkvURQsLbBvXrZfSF1T5HrU+uBg= X-Original-To: gcc-patches@gcc.gnu.org Delivered-To: gcc-patches@gcc.gnu.org Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by sourceware.org (Postfix) with ESMTPS id DD7683857C49 for ; Thu, 10 Mar 2022 11:26:40 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org DD7683857C49 Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 24149210EE for ; Thu, 10 Mar 2022 11:26:40 +0000 (UTC) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 10E3513FA3 for ; Thu, 10 Mar 2022 11:26:40 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id e6n4AnDgKWLpDAAAMHmgww (envelope-from ) for ; Thu, 10 Mar 2022 11:26:40 +0000 Date: Thu, 10 Mar 2022 12:26:38 +0100 To: gcc-patches@gcc.gnu.org Subject: [committed][nvptx] Handle unused result in nvptx_unisimt_handle_set Message-ID: <20220310112636.GA19747@delia.home> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.10.1 (2018-07-13) X-Spam-Status: No, score=-12.6 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, KAM_SHORT, SPF_HELO_NONE, SPF_PASS, TXREP, T_SCC_BODY_TEXT_LINE 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-patches@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-Patchwork-Original-From: Tom de Vries via Gcc-patches From: Tom de Vries Reply-To: Tom de Vries Errors-To: gcc-patches-bounces+patchwork=sourceware.org@gcc.gnu.org Sender: "Gcc-patches" Hi, For an example: ... #pragma omp target map(tofrom: counter_N0) #pragma omp simd for (int i = 0 ; i < 1 ; i++ ) { #pragma omp atomic update counter_N0 = counter_N0 + 1 ; } ... I noticed that the result of the atomic update (%r30) is propagated: ... @%r33 atom.add.u32 _, [%r29], 1; shfl.sync.idx.b32 %r30, %r30, %r32, 31, 0xffffffff; ... even though it is unused (which is why the bit bucket operand _ is used). Fix this by not emitting the shuffle in this case, such that we have instead: ... @%r33 atom.add.u32 _, [%r29], 1; bar.warp.sync 0xffffffff; ... Tested on nvptx. Committed to trunk. Thanks, - Tom [nvptx] Handle unused result in nvptx_unisimt_handle_set gcc/ChangeLog: 2022-03-07 Tom de Vries * config/nvptx/nvptx.cc (nvptx_unisimt_handle_set): Handle unused result. gcc/testsuite/ChangeLog: 2022-03-07 Tom de Vries * gcc.target/nvptx/uniform-simt-4.c: New test. --- gcc/config/nvptx/nvptx.cc | 4 +++- gcc/testsuite/gcc.target/nvptx/uniform-simt-4.c | 22 ++++++++++++++++++++++ 2 files changed, 25 insertions(+), 1 deletion(-) diff --git a/gcc/config/nvptx/nvptx.cc b/gcc/config/nvptx/nvptx.cc index 14911bd15f1..c41e305a34f 100644 --- a/gcc/config/nvptx/nvptx.cc +++ b/gcc/config/nvptx/nvptx.cc @@ -3274,7 +3274,9 @@ static bool nvptx_unisimt_handle_set (rtx set, rtx_insn *insn, rtx master) { rtx reg; - if (GET_CODE (set) == SET && REG_P (reg = SET_DEST (set))) + if (GET_CODE (set) == SET + && REG_P (reg = SET_DEST (set)) + && find_reg_note (insn, REG_UNUSED, reg) == NULL_RTX) { emit_insn_after (nvptx_gen_shuffle (reg, reg, master, SHUFFLE_IDX), insn); diff --git a/gcc/testsuite/gcc.target/nvptx/uniform-simt-4.c b/gcc/testsuite/gcc.target/nvptx/uniform-simt-4.c new file mode 100644 index 00000000000..c33de7a4111 --- /dev/null +++ b/gcc/testsuite/gcc.target/nvptx/uniform-simt-4.c @@ -0,0 +1,22 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -muniform-simt -mptx=_" } */ + +enum memmodel +{ + MEMMODEL_RELAXED = 0 +}; + +unsigned long long int *p64; +unsigned long long int v64; + +int +main() +{ + __atomic_fetch_add (p64, v64, MEMMODEL_RELAXED); + + return 0; +} + +/* { dg-final { scan-assembler-times "atom.add.u64\[\t \]+_," 1 } } */ +/* { dg-final { scan-assembler-times "bar.warp.sync" 1 } } */ +/* { dg-final { scan-assembler-not "shfl.sync.idx" } } */