From patchwork Fri Oct 18 16:10:44 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 1179512 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com 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 ozlabs.org (Postfix) with ESMTPS id 46vrj86cnJz9sPJ for ; Sat, 19 Oct 2019 03:15:08 +1100 (AEDT) Received: from localhost ([::1]:42774 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iLUu9-0002k1-RB for incoming@patchwork.ozlabs.org; Fri, 18 Oct 2019 12:15:05 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:49065) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iLUqP-0007bP-Ui for qemu-devel@nongnu.org; Fri, 18 Oct 2019 12:11:16 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iLUqL-0007Yz-6X for qemu-devel@nongnu.org; Fri, 18 Oct 2019 12:11:11 -0400 Received: from mx1.redhat.com ([209.132.183.28]:40240) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iLUqL-0007Uy-0D; Fri, 18 Oct 2019 12:11:09 -0400 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id D424418C4276; Fri, 18 Oct 2019 16:11:02 +0000 (UTC) Received: from t460s.redhat.com (unknown [10.36.118.23]) by smtp.corp.redhat.com (Postfix) with ESMTP id 54A963DB4; Fri, 18 Oct 2019 16:11:01 +0000 (UTC) From: David Hildenbrand To: qemu-devel@nongnu.org Subject: [PATCH v1 6/6] s390x/tcg: Fix VECTOR SUBTRACT WITH BORROW COMPUTE BORROW INDICATION Date: Fri, 18 Oct 2019 18:10:44 +0200 Message-Id: <20191018161044.6983-7-david@redhat.com> In-Reply-To: <20191018161044.6983-1-david@redhat.com> References: <20191018161044.6983-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.6.2 (mx1.redhat.com [10.5.110.62]); Fri, 18 Oct 2019 16:11:02 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Thomas Huth , David Hildenbrand , Ivan Warren , Cornelia Huck , Richard Henderson , qemu-s390x@nongnu.org Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" The numbers are unsigned, the computation is wrong. "Each operand is treated as an unsigned binary integer". Let's implement as given in the PoP: "A subtraction is performed by adding the contents of the second operand with the bitwise complement of the third operand along with a borrow indication from the rightmost bit of the fourth operand." Fixes: bc725e65152c ("s390x/tcg: Implement VECTOR SUBTRACT WITH BORROW COMPUTE BORROW INDICATION") Signed-off-by: David Hildenbrand --- target/s390x/translate_vx.inc.c | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-) diff --git a/target/s390x/translate_vx.inc.c b/target/s390x/translate_vx.inc.c index 87b5790db4..2015af9012 100644 --- a/target/s390x/translate_vx.inc.c +++ b/target/s390x/translate_vx.inc.c @@ -2240,17 +2240,30 @@ static void gen_sbcbi2_i64(TCGv_i64 dl, TCGv_i64 dh, TCGv_i64 al, TCGv_i64 ah, { TCGv_i64 th = tcg_temp_new_i64(); TCGv_i64 tl = tcg_temp_new_i64(); + TCGv_i64 sh = tcg_temp_new_i64(); + TCGv_i64 sl = tcg_temp_new_i64(); TCGv_i64 zero = tcg_const_i64(0); tcg_gen_andi_i64(tl, cl, 1); - tcg_gen_sub2_i64(tl, th, al, zero, tl, zero); - tcg_gen_sub2_i64(tl, th, tl, th, bl, zero); + tcg_gen_not_i64(sl, bl); + tcg_gen_not_i64(sh, bh); + + /* Add the borrow to the low doubleword of a */ + tcg_gen_add2_i64(tl, th, al, zero, tl, zero); + /* Add the bit-wise complement of b to the low doubleword */ + tcg_gen_add2_i64(tl, th, tl, th, sl, zero); + /* Isolate the carry to the high doubleword */ tcg_gen_andi_i64(th, th, 1); - tcg_gen_sub2_i64(tl, th, ah, zero, th, zero); - tcg_gen_sub2_i64(tl, th, tl, th, bh, zero); + /* Add the carry to the high doubleword of a */ + tcg_gen_add2_i64(tl, th, ah, zero, th, zero); + /* Add the bit-wise complement of b to the high doubleword */ + tcg_gen_add2_i64(tl, th, tl, th, sh, zero); + /* Isolate the carry to the next doubleword */ tcg_gen_andi_i64(dl, th, 1); tcg_gen_mov_i64(dh, zero); + tcg_temp_free_i64(sl); + tcg_temp_free_i64(sh); tcg_temp_free_i64(tl); tcg_temp_free_i64(th); tcg_temp_free_i64(zero);