From patchwork Mon Mar 20 23:08:14 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Roth X-Patchwork-Id: 741267 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3vnBvt1j43z9s06 for ; Tue, 21 Mar 2017 10:28:26 +1100 (AEDT) Received: from localhost ([::1]:35574 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cq6it-0000PC-LO for incoming@patchwork.ozlabs.org; Mon, 20 Mar 2017 19:28:23 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41184) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cq6Qp-0001oB-2p for qemu-devel@nongnu.org; Mon, 20 Mar 2017 19:09:49 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cq6Qk-00052e-8N for qemu-devel@nongnu.org; Mon, 20 Mar 2017 19:09:43 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:40051 helo=mx0a-001b2d01.pphosted.com) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cq6Qk-000520-2n for qemu-devel@nongnu.org; Mon, 20 Mar 2017 19:09:38 -0400 Received: from pps.filterd (m0098416.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v2KN8WLD028679 for ; Mon, 20 Mar 2017 19:09:37 -0400 Received: from e18.ny.us.ibm.com (e18.ny.us.ibm.com [129.33.205.208]) by mx0b-001b2d01.pphosted.com with ESMTP id 29amb5t7c6-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Mon, 20 Mar 2017 19:09:37 -0400 Received: from localhost by e18.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Mon, 20 Mar 2017 19:09:34 -0400 Received: from b01ledav005.gho.pok.ibm.com (b01ledav005.gho.pok.ibm.com [9.57.199.110]) by b01cxnp23034.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id v2KN9Yl546334062; Mon, 20 Mar 2017 23:09:34 GMT Received: from b01ledav005.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 8A9E0AE052; Mon, 20 Mar 2017 19:09:26 -0400 (EDT) Received: from localhost (unknown [9.53.92.194]) by b01ledav005.gho.pok.ibm.com (Postfix) with ESMTP id 70409AE04B; Mon, 20 Mar 2017 19:09:26 -0400 (EDT) From: Michael Roth To: qemu-devel@nongnu.org Date: Mon, 20 Mar 2017 18:08:14 -0500 X-Mailer: git-send-email 2.7.4 In-Reply-To: <1490051325-3770-1-git-send-email-mdroth@linux.vnet.ibm.com> References: <1490051325-3770-1-git-send-email-mdroth@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 17032023-0044-0000-0000-000002E066E2 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00006819; HX=3.00000240; KW=3.00000007; PH=3.00000004; SC=3.00000206; SDB=6.00836551; UDB=6.00411161; IPR=6.00614321; BA=6.00005224; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00014732; XFM=3.00000013; UTC=2017-03-20 23:09:36 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17032023-0045-0000-0000-0000070E6789 Message-Id: <1490051325-3770-51-git-send-email-mdroth@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2017-03-20_16:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=1 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1702020001 definitions=main-1703200196 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [generic] [fuzzy] X-Received-From: 148.163.158.5 Subject: [Qemu-devel] [PATCH 50/81] tcg/aarch64: Fix addsub2 for 0+C X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: qemu-stable@nongnu.org, Richard Henderson Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" From: Richard Henderson When al == xzr, we cannot use addi/subi because that encodes xsp. Force a zero into the temp register for that (rare) case. Signed-off-by: Richard Henderson Message-Id: <20161207180727.6286-2-rth@twiddle.net> (cherry picked from commit b1eb20da625897244e9621dabcf63d899deca54d) Signed-off-by: Michael Roth --- tcg/aarch64/tcg-target.inc.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/tcg/aarch64/tcg-target.inc.c b/tcg/aarch64/tcg-target.inc.c index 1939d35..6c68681 100644 --- a/tcg/aarch64/tcg-target.inc.c +++ b/tcg/aarch64/tcg-target.inc.c @@ -965,6 +965,15 @@ static inline void tcg_out_addsub2(TCGContext *s, int ext, TCGReg rl, insn = I3401_SUBSI; bl = -bl; } + if (unlikely(al == TCG_REG_XZR)) { + /* ??? We want to allow al to be zero for the benefit of + negation via subtraction. However, that leaves open the + possibility of adding 0+const in the low part, and the + immediate add instructions encode XSP not XZR. Don't try + anything more elaborate here than loading another zero. */ + al = TCG_REG_TMP; + tcg_out_movi(s, ext, al, 0); + } tcg_out_insn_3401(s, insn, ext, rl, al, bl); } else { tcg_out_insn_3502(s, sub ? I3502_SUBS : I3502_ADDS, ext, rl, al, bl);