From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 8471DC433EF for ; Fri, 1 Apr 2022 15:25:48 +0000 (UTC) Received: from localhost ([::1]:45102 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1naJ9n-0003ZS-KG for qemu-devel@archiver.kernel.org; Fri, 01 Apr 2022 11:25:47 -0400 Received: from eggs.gnu.org ([209.51.188.92]:50850) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1naJ7f-00011A-53 for qemu-devel@nongnu.org; Fri, 01 Apr 2022 11:23:35 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:36328) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1naJ7d-0000r1-LS for qemu-devel@nongnu.org; Fri, 01 Apr 2022 11:23:34 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1648826612; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=PxUM9gXylkG6Gj+SSFfAy4oYM7r8dYARxB6sPw5viT0=; b=Ztll4EpU9FTLrxPUxoHNQl1NK5odn/dh4pUf6XeSQSiNWMjTKPDsRyoRF5ty1DFsze4W23 LTPvuSOGB5KlM/NAzZy6nBUe17nrVDvnpcqn47RooJ693oNDnQAmAW2knwVTZ4PP/BIVsM up6GuUpJvUQOG/N+jkv0jgZ0F4bcGxg= 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-608-jsvheyM9M-a8SMgbvy_sxg-1; Fri, 01 Apr 2022 11:23:30 -0400 X-MC-Unique: jsvheyM9M-a8SMgbvy_sxg-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id A9D36101161B; Fri, 1 Apr 2022 15:23:29 +0000 (UTC) Received: from thuth.com (unknown [10.39.192.146]) by smtp.corp.redhat.com (Postfix) with ESMTP id 89BB92166B4E; Fri, 1 Apr 2022 15:23:28 +0000 (UTC) From: Thomas Huth To: qemu-devel@nongnu.org Subject: [PULL 2/6] target/s390x: Fix determination of overflow condition code after addition Date: Fri, 1 Apr 2022 17:23:19 +0200 Message-Id: <20220401152323.52519-3-thuth@redhat.com> In-Reply-To: <20220401152323.52519-1-thuth@redhat.com> References: <20220401152323.52519-1-thuth@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=thuth@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 8bit Content-Type: application/octet-stream; x-default=true Received-SPF: pass client-ip=170.10.133.124; envelope-from=thuth@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -15 X-Spam_score: -1.6 X-Spam_bar: - X-Spam_report: (-1.6 / 5.0 requ) BAYES_00=-1.9, BODY_EMPTY=1.31, DKIMWL_WL_HIGH=-0.082, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Maydell , Bruno Haible Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: Bruno Haible This program currently prints different results when run with TCG instead of running on real s390x hardware: #include int overflow_32 (int x, int y) { int sum; return ! __builtin_add_overflow (x, y, &sum); } int overflow_64 (long long x, long long y) { long sum; return ! __builtin_add_overflow (x, y, &sum); } int a1 = -2147483648; int b1 = -2147483648; long long a2 = -9223372036854775808L; long long b2 = -9223372036854775808L; int main () { { int a = a1; int b = b1; printf ("a = 0x%x, b = 0x%x\n", a, b); printf ("no_overflow = %d\n", overflow_32 (a, b)); } { long long a = a2; long long b = b2; printf ("a = 0x%llx, b = 0x%llx\n", a, b); printf ("no_overflow = %d\n", overflow_64 (a, b)); } } Signed-off-by: Bruno Haible Resolves: https://gitlab.com/qemu-project/qemu/-/issues/616 Message-Id: <20220323162621.139313-2-thuth@redhat.com> Signed-off-by: Thomas Huth --- target/s390x/tcg/cc_helper.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/target/s390x/tcg/cc_helper.c b/target/s390x/tcg/cc_helper.c index 8d04097f78..e11cdb745d 100644 --- a/target/s390x/tcg/cc_helper.c +++ b/target/s390x/tcg/cc_helper.c @@ -136,7 +136,7 @@ static uint32_t cc_calc_subu(uint64_t borrow_out, uint64_t result) static uint32_t cc_calc_add_64(int64_t a1, int64_t a2, int64_t ar) { - if ((a1 > 0 && a2 > 0 && ar < 0) || (a1 < 0 && a2 < 0 && ar > 0)) { + if ((a1 > 0 && a2 > 0 && ar < 0) || (a1 < 0 && a2 < 0 && ar >= 0)) { return 3; /* overflow */ } else { if (ar < 0) { @@ -196,7 +196,7 @@ static uint32_t cc_calc_comp_64(int64_t dst) static uint32_t cc_calc_add_32(int32_t a1, int32_t a2, int32_t ar) { - if ((a1 > 0 && a2 > 0 && ar < 0) || (a1 < 0 && a2 < 0 && ar > 0)) { + if ((a1 > 0 && a2 > 0 && ar < 0) || (a1 < 0 && a2 < 0 && ar >= 0)) { return 3; /* overflow */ } else { if (ar < 0) { -- 2.27.0