From patchwork Wed Dec 7 13:54:18 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Richard Biener X-Patchwork-Id: 1713321 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=gcc.gnu.org (client-ip=8.43.85.97; helo=sourceware.org; envelope-from=gcc-patches-bounces+incoming=patchwork.ozlabs.org@gcc.gnu.org; receiver=) Authentication-Results: legolas.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=gcc.gnu.org header.i=@gcc.gnu.org header.a=rsa-sha256 header.s=default header.b=TjkRVlPl; dkim-atps=neutral Received: from sourceware.org (server2.sourceware.org [8.43.85.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-384) server-digest SHA384) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4NRzLD2T1vz23ys for ; Thu, 8 Dec 2022 00:54:42 +1100 (AEDT) Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id AD8D43894C06 for ; Wed, 7 Dec 2022 13:54:39 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org AD8D43894C06 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1670421279; bh=2QyhbIRmUOtivusGsVtefRrYwdgF44KDqYG020fu000=; h=Date:To:cc:Subject:List-Id:List-Unsubscribe:List-Archive: List-Post:List-Help:List-Subscribe:From:Reply-To:From; b=TjkRVlPlvRl6nuPLCTK02RkWdHduuDy5/Dq5fOetsNYMuDmQefrq0r2M1qoe5dinF X6Vvdmpzx42GT6SmflErnPt7+aP9JUEhl6JdyDjH1hBDh5aFBLZS5cRwZBl3NAjbR9 xulsGVsZAiMIuMNsX2LAWqb/CNtvNNezPIBJEIMg= X-Original-To: gcc-patches@gcc.gnu.org Delivered-To: gcc-patches@gcc.gnu.org Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by sourceware.org (Postfix) with ESMTPS id 2A1DD3888C56 for ; Wed, 7 Dec 2022 13:54:20 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 2A1DD3888C56 Received: from imap1.suse-dmz.suse.de (imap1.suse-dmz.suse.de [192.168.254.73]) (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-out2.suse.de (Postfix) with ESMTPS id 1658A1FEEA; Wed, 7 Dec 2022 13:54:19 +0000 (UTC) Received: from imap1.suse-dmz.suse.de (imap1.suse-dmz.suse.de [192.168.254.73]) (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 imap1.suse-dmz.suse.de (Postfix) with ESMTPS id F35F4136B4; Wed, 7 Dec 2022 13:54:18 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap1.suse-dmz.suse.de with ESMTPSA id /h9nOgqbkGMFfgAAGKfGzw (envelope-from ); Wed, 07 Dec 2022 13:54:18 +0000 Date: Wed, 7 Dec 2022 14:54:18 +0100 (CET) To: gcc-patches@gcc.gnu.org cc: Jakub Jelinek Subject: [PATCH] tree-optimization/106904 - bogus -Wstringopt-overflow with vectors MIME-Version: 1.0 Message-Id: <20221207135418.F35F4136B4@imap1.suse-dmz.suse.de> X-Spam-Status: No, score=-11.8 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, 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 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: Richard Biener via Gcc-patches From: Richard Biener Reply-To: Richard Biener Errors-To: gcc-patches-bounces+incoming=patchwork.ozlabs.org@gcc.gnu.org Sender: "Gcc-patches" The following avoids CSE of &ps->wp to &ps->wp.hwnd confusing -Wstringopt-overflow by making sure to produce addresses to the biggest container from vectorization. For this I introduce strip_zero_offset_components which turns &ps->wp.hwnd into &(*ps) and use that to base the vector data references on. That will also work for addresses with variable components, alternatively emitting pointer arithmetic via calling get_inner_reference and gimplifying that would be possible but likely more intrusive. This is by no means a complete fix for all of those issues (avoiding ADDR_EXPRs in favor of pointer arithmetic might be). Other passes will have similar issues. In theory that might now cause false negatives. Bootstrap and regtest running on x86_64-unknown-linux-gnu. Any opinion? Thanks, Richard. PR tree-optimization/106904 * tree.h (strip_zero_offset_components): Declare. * tree.cc (strip_zero_offset_components): Define. * tree-vect-data-refs.cc (vect_create_addr_base_for_vector_ref): Strip zero offset components before building the address. * gcc.dg/Wstringop-overflow-pr106904.c: New testcase. --- .../gcc.dg/Wstringop-overflow-pr106904.c | 30 +++++++++++++++++++ gcc/tree-vect-data-refs.cc | 12 ++++---- gcc/tree.cc | 12 ++++++++ gcc/tree.h | 1 + 4 files changed, 50 insertions(+), 5 deletions(-) create mode 100644 gcc/testsuite/gcc.dg/Wstringop-overflow-pr106904.c diff --git a/gcc/testsuite/gcc.dg/Wstringop-overflow-pr106904.c b/gcc/testsuite/gcc.dg/Wstringop-overflow-pr106904.c new file mode 100644 index 00000000000..15e67c28c15 --- /dev/null +++ b/gcc/testsuite/gcc.dg/Wstringop-overflow-pr106904.c @@ -0,0 +1,30 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -Wstringop-overflow -fno-vect-cost-model" } */ + +struct windowpos +{ + int hwnd; + int hwnd2; +}; + +struct packed_windowpos +{ + int hwnd; + int pad1; + int hwnd2; + int pad2; +}; + +struct packed_structs +{ + struct packed_windowpos wp; +}; + +void func(struct packed_structs *ps) +{ + struct windowpos wp; + + wp.hwnd = ps->wp.hwnd; + wp.hwnd2 = ps->wp.hwnd2; + __builtin_memcpy(&ps->wp, &wp, sizeof(wp)); /* { dg-bogus "into a region" } */ +} diff --git a/gcc/tree-vect-data-refs.cc b/gcc/tree-vect-data-refs.cc index 6c892791bd4..18b0f962670 100644 --- a/gcc/tree-vect-data-refs.cc +++ b/gcc/tree-vect-data-refs.cc @@ -4845,11 +4845,13 @@ vect_create_addr_base_for_vector_ref (vec_info *vinfo, stmt_vec_info stmt_info, if (loop_vinfo) addr_base = fold_build_pointer_plus (data_ref_base, base_offset); else - { - addr_base = build1 (ADDR_EXPR, - build_pointer_type (TREE_TYPE (DR_REF (dr))), - unshare_expr (DR_REF (dr))); - } + addr_base = build1 (ADDR_EXPR, + build_pointer_type (TREE_TYPE (DR_REF (dr))), + /* Strip zero offset components since we don't need + them and they can confuse late diagnostics if + we CSE them wrongly. See PR106904 for example. */ + unshare_expr (strip_zero_offset_components + (DR_REF (dr)))); vect_ptr_type = build_pointer_type (TREE_TYPE (DR_REF (dr))); dest = vect_get_new_vect_var (vect_ptr_type, vect_pointer_var, base_name); diff --git a/gcc/tree.cc b/gcc/tree.cc index b40c95ae8c4..0a51f9ddb4d 100644 --- a/gcc/tree.cc +++ b/gcc/tree.cc @@ -12014,6 +12014,18 @@ strip_invariant_refs (const_tree op) return op; } +/* Strip handled components with zero offset from OP. */ + +tree +strip_zero_offset_components (tree op) +{ + while (TREE_CODE (op) == COMPONENT_REF + && integer_zerop (DECL_FIELD_OFFSET (TREE_OPERAND (op, 1))) + && integer_zerop (DECL_FIELD_BIT_OFFSET (TREE_OPERAND (op, 1)))) + op = TREE_OPERAND (op, 0); + return op; +} + static GTY(()) tree gcc_eh_personality_decl; /* Return the GCC personality function decl. */ diff --git a/gcc/tree.h b/gcc/tree.h index 1c810c0b21b..065ad527c3f 100644 --- a/gcc/tree.h +++ b/gcc/tree.h @@ -5373,6 +5373,7 @@ extern bool tree_nop_conversion_p (const_tree, const_tree); extern tree tree_strip_nop_conversions (tree); extern tree tree_strip_sign_nop_conversions (tree); extern const_tree strip_invariant_refs (const_tree); +extern tree strip_zero_offset_components (tree); extern tree lhd_gcc_personality (void); extern void assign_assembler_name_if_needed (tree); extern bool warn_deprecated_use (tree, tree);