From patchwork Mon Feb 25 19:01:17 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Richard Henderson X-Patchwork-Id: 223015 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 0AF922C008C for ; Tue, 26 Feb 2013 06:02:43 +1100 (EST) Received: from localhost ([::1]:45420 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UA3Jw-00044q-MM for incoming@patchwork.ozlabs.org; Mon, 25 Feb 2013 14:02:40 -0500 Received: from eggs.gnu.org ([208.118.235.92]:38089) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UA3JX-0003mK-Qt for qemu-devel@nongnu.org; Mon, 25 Feb 2013 14:02:18 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UA3JH-0004Yo-2G for qemu-devel@nongnu.org; Mon, 25 Feb 2013 14:02:12 -0500 Received: from mail-qa0-f52.google.com ([209.85.216.52]:39882) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UA3JG-0004XV-TB for qemu-devel@nongnu.org; Mon, 25 Feb 2013 14:01:58 -0500 Received: by mail-qa0-f52.google.com with SMTP id bs12so1781976qab.4 for ; Mon, 25 Feb 2013 11:01:57 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=x-received:sender:from:to:cc:subject:date:message-id:x-mailer :in-reply-to:references; bh=3asfvQSFQwX4tSQskA4HDFrFWITKSTCYM2XahM51vKg=; b=JYEzPZZz2tpcKiXwGDJ0mnORwTitI9rB5/1Wd2nDN2b5bhvDT7YtzP7qOKRc7Jg0dl QH65yukD0Z6Jf5LuB0cSrd3onOWTRUFN6C21bIQk4w/IXBdKi/hAajrdDRnjY+bHW92E udM5H5bV4JgpFS/1YQZAeXvH3k4XQbAvdm9tmckKjMtvwE5jimdRrGCO/2k39KI3Ozv6 q9lKmDUCJeSKX/XV6iw3XhuMd80xN8wP0KXbYfK2FZbJ6nkZleDVsmWGSqXbjDSL1XMU GbChvq0XmF5YoB/3++fUAyYko4ndWTJWs8PbJAiHjMMUH8MZE2AK/UwNekRmOKzWWHiY ghog== X-Received: by 10.224.189.10 with SMTP id dc10mr12969109qab.55.1361818917339; Mon, 25 Feb 2013 11:01:57 -0800 (PST) Received: from anchor.com (50-194-63-110-static.hfc.comcastbusiness.net. [50.194.63.110]) by mx.google.com with ESMTPS id gw9sm17992087qab.10.2013.02.25.11.01.55 (version=TLSv1.2 cipher=RC4-SHA bits=128/128); Mon, 25 Feb 2013 11:01:56 -0800 (PST) From: Richard Henderson To: qemu-devel@nongnu.org Date: Mon, 25 Feb 2013 11:01:17 -0800 Message-Id: <1361818877-8739-4-git-send-email-rth@twiddle.net> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1361818877-8739-1-git-send-email-rth@twiddle.net> References: <1361818877-8739-1-git-send-email-rth@twiddle.net> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [fuzzy] X-Received-From: 209.85.216.52 Cc: Anthony Liguori , Alexander Graf Subject: [Qemu-devel] [PATCH v2 3/3] target-ppc: Fix SUBFE carry 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 While ~T0+T1+CF = T1-T0+CF-1 is true for the low 32-bits, it does not produce the correct carry-out to bit 33. Do exactly what the manual says. Cc: Alexander Graf Signed-off-by: Richard Henderson Reviewed-by: Peter Maydell --- target-ppc/translate.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/target-ppc/translate.c b/target-ppc/translate.c index f886441..80d5366 100644 --- a/target-ppc/translate.c +++ b/target-ppc/translate.c @@ -1120,14 +1120,15 @@ static inline void gen_op_arith_subf(DisasContext *ctx, TCGv ret, TCGv arg1, } if (add_ca) { - /* dest = ~arg1 + arg2 + ca = arg2 - arg1 + ca - 1. */ + /* dest = ~arg1 + arg2 + ca. */ if (compute_ca) { - TCGv zero; - tcg_gen_subi_tl(cpu_ca, cpu_ca, 1); + TCGv zero, inv1 = tcg_temp_new(); + tcg_gen_not_tl(inv1, arg1); zero = tcg_const_tl(0); tcg_gen_add2_tl(t0, cpu_ca, arg2, zero, cpu_ca, zero); - tcg_gen_sub2_tl(t0, cpu_ca, t0, cpu_ca, arg1, zero); + tcg_gen_add2_tl(t0, cpu_ca, t0, cpu_ca, inv1, zero); tcg_temp_free(zero); + tcg_temp_free(inv1); } else { tcg_gen_sub_tl(t0, arg2, arg1); tcg_gen_add_tl(t0, t0, cpu_ca);