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 E3AC83858C78 for ; Fri, 17 Feb 2023 11:31:01 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org E3AC83858C78 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 C3AC722534 for ; Fri, 17 Feb 2023 11:31:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1676633460; h=from:from:reply-to:date:date:to:to:cc:mime-version:mime-version: content-type:content-type; bh=T8IACNY2zACeJ+tQgKy+KY1k0jHMOnJtJFN3vHJypBQ=; b=crM0OhzWOnOao0cXZ3U+tcjwMSlJDJLsm973bZvsVqYzP+Ey8tgW5dwRDBq/PzFkN67sy2 sem0EeEPb0/gNhym8lCp9ptjVOyzt4KWYW1zCgLhvv49hCwzcSvVqeEmn9IFdD/8m4PctN hEn9HubmOfsfGFO7+L9hdWlIpYRw/BU= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1676633460; h=from:from:reply-to:date:date:to:to:cc:mime-version:mime-version: content-type:content-type; bh=T8IACNY2zACeJ+tQgKy+KY1k0jHMOnJtJFN3vHJypBQ=; b=ejS3lsL/ttq5IjN7VWjYnPAzOw4rN/tU2b4xOsUHL4zvDtXXDcmTCLETY+2BejoWUVd7A5 ddATCwzYjX+g3fDg== 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 B7DF12C141 for ; Fri, 17 Feb 2023 11:30:59 +0000 (UTC) Date: Fri, 17 Feb 2023 11:30:59 +0000 (UTC) From: Richard Biener To: gcc-patches@gcc.gnu.org Subject: [PATCH] Fix wrong-code issue in VN 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,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: <20230217113059.X3O9Trt8z3Tqpgh-qPfb-qv_jHqusBQIehgRkCR1jyo@z> The following fixes the wrong removed dead store discovered on the PR108657 testcase when the reported DSE issue is not fixed. The issue is we were using ssa_undefined_value_p on virtual operands which returns a result based on the real definition of the definition statement. That doesn't make sense so this patch guards the calls properly and makes sure nobody else does the same mistake. Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed. * tree-ssa.cc (ssa_undefined_value_p): Assert we are not called on virtual operands. * tree-ssa-sccvn.cc (vn_phi_lookup): Guard ssa_undefined_value_p calls. (vn_phi_insert): Likewise. (set_ssa_val_to): Likewise. (visit_phi): Avoid extra work with equivalences for virtual operand PHIs. --- gcc/tree-ssa-sccvn.cc | 20 +++++++++++++++----- gcc/tree-ssa.cc | 2 ++ 2 files changed, 17 insertions(+), 5 deletions(-) diff --git a/gcc/tree-ssa-sccvn.cc b/gcc/tree-ssa-sccvn.cc index 8ee77fd2b78..d5b081a309f 100644 --- a/gcc/tree-ssa-sccvn.cc +++ b/gcc/tree-ssa-sccvn.cc @@ -4824,7 +4824,8 @@ vn_phi_lookup (gimple *phi, bool backedges_varying_p) if (TREE_CODE (def) == SSA_NAME && (!backedges_varying_p || !(e->flags & EDGE_DFS_BACK))) { - if (ssa_undefined_value_p (def, false)) + if (!virtual_operand_p (def) + && ssa_undefined_value_p (def, false)) def = VN_TOP; else def = SSA_VAL (def); @@ -4877,7 +4878,8 @@ vn_phi_insert (gimple *phi, tree result, bool backedges_varying_p) if (TREE_CODE (def) == SSA_NAME && (!backedges_varying_p || !(e->flags & EDGE_DFS_BACK))) { - if (ssa_undefined_value_p (def, false)) + if (!virtual_operand_p (def) + && ssa_undefined_value_p (def, false)) def = VN_TOP; else def = SSA_VAL (def); @@ -5059,6 +5061,7 @@ set_ssa_val_to (tree from, tree to) } curr_invariant = is_gimple_min_invariant (currval); curr_undefined = (TREE_CODE (currval) == SSA_NAME + && !virtual_operand_p (currval) && ssa_undefined_value_p (currval, false)); if (currval != VN_TOP && !curr_invariant @@ -5081,6 +5084,7 @@ set_ssa_val_to (tree from, tree to) else if (currval != VN_TOP && !curr_undefined && TREE_CODE (to) == SSA_NAME + && !virtual_operand_p (to) && ssa_undefined_value_p (to, false)) { if (dump_file && (dump_flags & TDF_DETAILS)) @@ -5116,6 +5120,7 @@ set_and_exit: PR82320 for a testcase were we'd otherwise not terminate iteration. */ && !(curr_undefined && TREE_CODE (to) == SSA_NAME + && !virtual_operand_p (to) && ssa_undefined_value_p (to, false)) /* ??? For addresses involving volatile objects or types operand_equal_p does not reliably detect ADDR_EXPRs as equal. We know we are only @@ -5880,7 +5885,14 @@ visit_phi (gimple *phi, bool *inserted, bool backedges_varying_p) sameval = def; sameval_e = e; } - else if (!expressions_equal_p (def, sameval)) + else if (expressions_equal_p (def, sameval)) + sameval_e = NULL; + else if (virtual_operand_p (def)) + { + sameval = NULL_TREE; + break; + } + else { /* We know we're arriving only with invariant addresses here, try harder comparing them. We can do some caching here @@ -5957,8 +5969,6 @@ visit_phi (gimple *phi, bool *inserted, bool backedges_varying_p) sameval = NULL_TREE; break; } - else - sameval_e = NULL; } /* If the value we want to use is flowing over the backedge and we diff --git a/gcc/tree-ssa.cc b/gcc/tree-ssa.cc index 5126020d40f..a5cad2d344e 100644 --- a/gcc/tree-ssa.cc +++ b/gcc/tree-ssa.cc @@ -1320,6 +1320,8 @@ ssa_undefined_value_p (tree t, bool partial) { gimple *def_stmt; + gcc_checking_assert (!virtual_operand_p (t)); + if (ssa_defined_default_def_p (t)) return false; -- 2.35.3