From patchwork Tue Mar 4 17:04:09 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Richard Henderson X-Patchwork-Id: 326414 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 C5B192C0086 for ; Wed, 5 Mar 2014 04:11:38 +1100 (EST) Received: from localhost ([::1]:46799 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WKssS-00015H-97 for incoming@patchwork.ozlabs.org; Tue, 04 Mar 2014 12:11:36 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33781) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WKsm8-0002B0-GT for qemu-devel@nongnu.org; Tue, 04 Mar 2014 12:05:10 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WKsm2-0001oY-NV for qemu-devel@nongnu.org; Tue, 04 Mar 2014 12:05:04 -0500 Received: from mail-qg0-x22a.google.com ([2607:f8b0:400d:c04::22a]:44445) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WKsm2-0001oO-J2 for qemu-devel@nongnu.org; Tue, 04 Mar 2014 12:04:58 -0500 Received: by mail-qg0-f42.google.com with SMTP id q107so16118485qgd.1 for ; Tue, 04 Mar 2014 09:04:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:from:to:cc:subject:date:message-id:in-reply-to:references; bh=eWFNIdtZmJH5citocaVBsuymv0AVoVgV3OWc/Vla+tA=; b=iCJ+c/J5yZIohbZBzvZxNyaf+FmwAQPb4zOblSSKTjCKxGb5KtCJnGM1zYIpSvEPi3 M8oR7s6tcbyraL/j2CGzo4tfjiRE4VaDXW/duFA1OrOkdvmzq6W2OQhf+nCdwnvHLzlM uCbvvpujaXHqCI/eRoQ/FJWD3QftjXoZaoa3dqFqqazA/5TG0cfzpweN4b11J40WcBh8 BnGTv/0W4yl1uIP6cdt+ABjv7Yoa5fbE0SLbK5YIcjqjDhRzEGLgnHfEaXX+VYxF2oMQ dbKW3AyL0nljMJG9iGbAfEdIZoqd1Dcq0V50ix/lpRZr2RFfbFhZEaabbmF6/jR0ntwH my4A== X-Received: by 10.229.125.193 with SMTP id z1mr1049332qcr.10.1393952698243; Tue, 04 Mar 2014 09:04:58 -0800 (PST) Received: from anchor.com (50-194-63-110-static.hfc.comcastbusiness.net. [50.194.63.110]) by mx.google.com with ESMTPSA id y19sm51159498qae.20.2014.03.04.09.04.56 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 04 Mar 2014 09:04:57 -0800 (PST) From: Richard Henderson To: qemu-devel@nongnu.org Date: Tue, 4 Mar 2014 09:04:09 -0800 Message-Id: <1393952650-16802-10-git-send-email-rth@twiddle.net> X-Mailer: git-send-email 1.8.5.3 In-Reply-To: <1393952650-16802-1-git-send-email-rth@twiddle.net> References: <1393952650-16802-1-git-send-email-rth@twiddle.net> X-detected-operating-system: by eggs.gnu.org: Error: Malformed IPv6 address (bad octet value). X-Received-From: 2607:f8b0:400d:c04::22a Cc: Peter Maydell , Claudio Fontana Subject: [Qemu-devel] [PATCH 09/10] tcg-aarch64: Simplify tcg_out_ldst_9 encoding X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org At first glance the code appears to be using 1's compliment encoding, a-la AArch32. Except that the constant is "off", creating a complicated split field 2's compliment encoding. Much clearer to just use a normal mask and shift. Signed-off-by: Richard Henderson --- tcg/aarch64/tcg-target.c | 14 ++------------ 1 file changed, 2 insertions(+), 12 deletions(-) diff --git a/tcg/aarch64/tcg-target.c b/tcg/aarch64/tcg-target.c index 58a5ff3..d75d685 100644 --- a/tcg/aarch64/tcg-target.c +++ b/tcg/aarch64/tcg-target.c @@ -305,18 +305,8 @@ static inline void tcg_out_ldst_9(TCGContext *s, TCGReg rd, TCGReg rn, tcg_target_long offset) { /* use LDUR with BASE register with 9bit signed unscaled offset */ - unsigned int mod, off; - - if (offset < 0) { - off = (256 + offset); - mod = 0x1; - } else { - off = offset; - mod = 0x0; - } - - mod |= op_type; - tcg_out32(s, op_data << 24 | mod << 20 | off << 12 | rn << 5 | rd); + tcg_out32(s, op_data << 24 | op_type << 20 + | (offset & 0x1ff) << 12 | rn << 5 | rd); } /* tcg_out_ldst_12 expects a scaled unsigned immediate offset */