From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp-out1.suse.de (smtp-out1.suse.de [IPv6:2001:67c:2178:6::1c]) by sourceware.org (Postfix) with ESMTPS id 81970384D1BE for ; Thu, 6 Oct 2022 10:07:09 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 81970384D1BE Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=suse.de Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=suse.de Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out1.suse.de (Postfix) with ESMTP id 74201219A4 for ; Thu, 6 Oct 2022 10:07:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1665050828; h=from:from:reply-to:date:date:to:to:cc:mime-version:mime-version: content-type:content-type; bh=g6tD1NZOjpQ9CwSwUq1f9SKoJOwjg1mNPPBwRQOW9sY=; b=TH9k74AB2eWfX+A8LfhJb78yVVaLc2aJ06aso/08S1cCehRTr/yuK4G7a9L5pyekLACqo5 mrYWypg+oTdI+UjlZ/Xh6GOOMGamcxH29hT7skF4A2Qezx7zAkJB17I/hRUcEZ+3qxK4vx pyzNMvWH5OkQGrHDFt+jnZUkIFMij88= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1665050828; h=from:from:reply-to:date:date:to:to:cc:mime-version:mime-version: content-type:content-type; bh=g6tD1NZOjpQ9CwSwUq1f9SKoJOwjg1mNPPBwRQOW9sY=; b=BD5PAmb7JE/wRvSVONDCU/mfl/aFZQ4HQPYigDf8VMrbmp/H1ac1CigfSYn9ziFDiEZaJi BJZidLlTD/1L9sDA== Received: from wotan.suse.de (wotan.suse.de [10.160.0.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by relay2.suse.de (Postfix) with ESMTPS id 48C242C16E for ; Thu, 6 Oct 2022 10:07:01 +0000 (UTC) Date: Thu, 6 Oct 2022 10:07:08 +0000 (UTC) From: Richard Biener To: gcc-patches@gcc.gnu.org Subject: [PATCH] tree-optimization/107107 - tail-merging VN wrong-code User-Agent: Alpine 2.22 (LSU 394 2020-01-19) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-Spam-Status: No, score=-10.6 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,GIT_PATCH_0,MISSING_MID,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS,TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: Message-ID: <20221006100708.6ph-PMVUP-3qYtVnDWr8R2IzVxais2IPZ3Z6GuG50do@z> The following fixes an unintended(?) side-effect of the special MODIFY_EXPR expression entries we add for tail-merging during VN. We shouldn't value-number the virtual operand differently here. Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed. PR tree-optimization/107107 * tree-ssa-sccvn.cc (visit_reference_op_store): Do not affect value-numbering when doing the tail merging MODIFY_EXPR lookup. * gcc.dg/pr107107.c: New testcase. --- gcc/testsuite/gcc.dg/pr107107.c | 25 +++++++++++++++++++++++++ gcc/tree-ssa-sccvn.cc | 17 +++-------------- 2 files changed, 28 insertions(+), 14 deletions(-) create mode 100644 gcc/testsuite/gcc.dg/pr107107.c diff --git a/gcc/testsuite/gcc.dg/pr107107.c b/gcc/testsuite/gcc.dg/pr107107.c new file mode 100644 index 00000000000..5ad6a63159e --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr107107.c @@ -0,0 +1,25 @@ +/* { dg-do run } */ +/* { dg-options "-O2 -ftree-tail-merge" } */ + +static inline void set_longish(int is_long_long, void *p, long x) +{ + if (is_long_long) + *(long long*)p = x; + else + *(long*)p = x; +} +static long test(long long *p, int index, int mode) +{ + *p = 1; + set_longish(mode, p+index, 2); + return *p; +} +long (*volatile vtest)(long long*, int, int) = test; +int main(void) +{ + long long x; + long result = vtest(&x, 0, 1); + if (result != 2 || x != 2) + __builtin_abort (); + return 0; +} diff --git a/gcc/tree-ssa-sccvn.cc b/gcc/tree-ssa-sccvn.cc index 2cc2c0e1e34..37484403c56 100644 --- a/gcc/tree-ssa-sccvn.cc +++ b/gcc/tree-ssa-sccvn.cc @@ -5718,19 +5718,6 @@ visit_reference_op_store (tree lhs, tree op, gimple *stmt) if (!resultsame) { - /* Only perform the following when being called from PRE - which embeds tail merging. */ - if (default_vn_walk_kind == VN_WALK) - { - assign = build2 (MODIFY_EXPR, TREE_TYPE (lhs), lhs, op); - vn_reference_lookup (assign, vuse, VN_NOWALK, &vnresult, false); - if (vnresult) - { - VN_INFO (vdef)->visited = true; - return set_ssa_val_to (vdef, vnresult->result_vdef); - } - } - if (dump_file && (dump_flags & TDF_DETAILS)) { fprintf (dump_file, "No store match\n"); @@ -5755,7 +5742,9 @@ visit_reference_op_store (tree lhs, tree op, gimple *stmt) if (default_vn_walk_kind == VN_WALK) { assign = build2 (MODIFY_EXPR, TREE_TYPE (lhs), lhs, op); - vn_reference_insert (assign, lhs, vuse, vdef); + vn_reference_lookup (assign, vuse, VN_NOWALK, &vnresult, false); + if (!vnresult) + vn_reference_insert (assign, lhs, vuse, vdef); } } else -- 2.35.3