From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by sourceware.org (Postfix) with ESMTPS id 8AFC33858425 for ; Thu, 22 Dec 2022 10:30:17 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 8AFC33858425 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=redhat.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1671705017; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type; bh=iRBOWLhtzbdBoY9fYa1EnR6jJ/SPRMuKVCEBSgUsjsE=; b=MNkORK48CpxYDDxPXHp4hxUyDJjvF+iUL1vf3pOXHiG0wmsUM8qiBcjb0W4hX2QivYqrMn jGfrSApM/W2nqBfmiaQckaSnZFKtPMIj5dxI1Q7KLLq5hR1m1udcwYokwfsBaYe7WzvD6v vNHuwNE2ppdNQij2/5/TqTIwrlQu9Ic= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-349-ZWXoqpj9NCC5eK9F8Urh8A-1; Thu, 22 Dec 2022 05:30:15 -0500 X-MC-Unique: ZWXoqpj9NCC5eK9F8Urh8A-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 21B89101A521; Thu, 22 Dec 2022 10:30:15 +0000 (UTC) Received: from tucnak.zalov.cz (unknown [10.39.195.114]) by smtp.corp.redhat.com (Postfix) with ESMTPS id ABE0853A0; Thu, 22 Dec 2022 10:30:14 +0000 (UTC) Received: from tucnak.zalov.cz (localhost [127.0.0.1]) by tucnak.zalov.cz (8.17.1/8.17.1) with ESMTPS id 2BMAUAWs1189295 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Thu, 22 Dec 2022 11:30:11 +0100 Received: (from jakub@localhost) by tucnak.zalov.cz (8.17.1/8.17.1/Submit) id 2BMAUAmT1189294; Thu, 22 Dec 2022 11:30:10 +0100 Date: Thu, 22 Dec 2022 11:30:09 +0100 From: Jakub Jelinek To: Richard Biener Cc: gcc-patches@gcc.gnu.org, Aldy Hernandez , Andrew MacLeod Subject: [PATCH] phiopt: Drop SSA_NAME_RANGE_INFO in maybe equal case [PR108166] Message-ID: Reply-To: Jakub Jelinek MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.5 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Spam-Status: No, score=-3.5 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_NONE,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: Hi! The following place in value_replacement is after proving that x == cst1 ? cst2 : x phi result is only used in a comparison with constant which doesn't care if it compares cst1 or cst2 and replaces it with x. The testcase is miscompiled because we have after the replacement incorrect range info for the phi result, we would need to effectively union the phi result range with cst1 (oarg in the code) because previously that constant might be missing in the range, but newly it can appear (we've just verified that the single use stmt of the phi result doesn't care about that value in particular). The following patch just resets the info, bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk? Aldy/Andrew, how would one instead union the SSA_NAME_RANGE_INFO with some INTEGER_CST and store it back into SSA_NAME_RANGE_INFO (including adjusting non-zero bits and the like)? 2022-12-22 Jakub Jelinek PR tree-optimization/108166 * tree-ssa-phiopt.cc (value_replacement): For the maybe_equal_p case turned into equal_p reset SSA_NAME_RANGE_INFO of phi result. * g++.dg/torture/pr108166.C: New test. --- gcc/tree-ssa-phiopt.cc.jj 2022-10-28 11:00:53.970243821 +0200 +++ gcc/tree-ssa-phiopt.cc 2022-12-21 14:27:58.118326548 +0100 @@ -1491,6 +1491,12 @@ value_replacement (basic_block cond_bb, default: break; } + if (equal_p) + /* After the optimization PHI result can have value + which it couldn't have previously. + We could instead of resetting it union the range + info with oarg. */ + reset_flow_sensitive_info (gimple_phi_result (phi)); if (equal_p && MAY_HAVE_DEBUG_BIND_STMTS) { imm_use_iterator imm_iter; --- gcc/testsuite/g++.dg/torture/pr108166.C.jj 2022-12-21 14:31:02.638661322 +0100 +++ gcc/testsuite/g++.dg/torture/pr108166.C 2022-12-21 14:30:45.441909725 +0100 @@ -0,0 +1,26 @@ +// PR tree-optimization/108166 +// { dg-do run } + +bool a, b; +int d, c; + +const int & +foo (const int &f, const int &g) +{ + return !f ? f : g; +} + +__attribute__((noipa)) void +bar (int) +{ +} + +int +main () +{ + c = foo (b, 0) > ((b ? d : b) ?: 8); + a = b ? d : b; + bar (a); + if (a != 0) + __builtin_abort (); +} Jakub