From patchwork Wed Jun 14 20:39:05 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Laurent Vivier X-Patchwork-Id: 775976 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 3wnz5P0YgSz9sCX for ; Thu, 15 Jun 2017 06:39:37 +1000 (AEST) Received: from localhost ([::1]:50751 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dLF4g-0006zA-H1 for incoming@patchwork.ozlabs.org; Wed, 14 Jun 2017 16:39:34 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36656) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dLF4P-0006z4-L7 for qemu-devel@nongnu.org; Wed, 14 Jun 2017 16:39:18 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dLF4M-0008Ht-Gr for qemu-devel@nongnu.org; Wed, 14 Jun 2017 16:39:17 -0400 Received: from mout.kundenserver.de ([217.72.192.75]:51148) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1dLF4M-0008H3-6c for qemu-devel@nongnu.org; Wed, 14 Jun 2017 16:39:14 -0400 Received: from localhost.localdomain ([78.238.229.36]) by mrelayeu.kundenserver.de (mreue102 [212.227.15.183]) with ESMTPSA (Nemesis) id 0MTQ1P-1dDuma3YGN-00SNlZ; Wed, 14 Jun 2017 22:39:08 +0200 From: Laurent Vivier To: qemu-devel@nongnu.org Date: Wed, 14 Jun 2017 22:39:05 +0200 Message-Id: <20170614203905.19657-1-laurent@vivier.eu> X-Mailer: git-send-email 2.9.4 X-Provags-ID: V03:K0:lQupb/teKUVnimiC3tC65CAl/vxaBP12edcA3RXiSkyedIuRVAn I3ZAdWi76nh4cN5+KfnmngwXTpN8XQKiSWi9SW6RDmk96GsP32BH9XWpkRLI8f9qG4XML9B rJdetJir6vGwjyNoLKy8+g9IBT6rsoJJJ2hHY75nkf265VSEmsLmW+1QM5PmYE8e7tyTPMX Ylo5TvaTVtDJmKaFAe0Yg== X-UI-Out-Filterresults: notjunk:1; V01:K0:rVAarQXXPmU=:ae+OQqxmROBy5M/ItpFLdD O9owku2uKyxo6zIfaJzlH9I5PsgUnWUSAmbkGeYWtIfoL9Gt8StzAVFLe30B7FBk0dR+blEXc zA+jEaadOd+eSljtSnvfq/ViNx+uInc2wQfFpWI+k4WqTOKEZtR49bYot5zgRzKE0ObsVLs87 8Kn+WRZs0BdPt7MaDX+yJOxjiR4EqcjzQPiYWksge7kihcts9jCAufHMhCn0olVeJiCUNkNa1 d3JcrCnr3c5SP9v4rTKn8FP4C2ZEZGXUBsth66yukPkq27mo9usvC6RmV9yO7LVrvStpM18eJ daRpIViZ0a3vJEU1FN4d8SV/8nsc/jVF+8QYQyRHfEOpZdtUpaf+4LAE/Wn5/JBfZ5f58T576 W0y1TKKgq+O2X9vY6vtJYZrxLuTFpNFsshMSsvIB7UlyAftWDZkNkCxVBfoBjnbd5Io9MLJdV ePySZqsX+xbZGXb13j4ZXXHxJnytD8/dNCTSUhZKl/DLCkPkUZTue14rgSzJQS6yGN+iaKdtT ILcxvQZmrgqaOMf8Dv6UgfmRduCfJH9j2+yMubIU0yp4BjvgnmpjYPTOAVnvD5LmhnNEqjS74 v9syqsQPSIftwL7MqoL4HlM3edXIKy6novUkgC7HP7X70Dizb9a7Bdki3trzGQ8rTtRvewXFA cD1qlaoxy8mE9+zTT/AbbX6ckiaJYwdWi3KKGAhBK1J66DKbG7GbltwHgYcxkXcpMoqQ= X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 217.72.192.75 Subject: [Qemu-devel] [PATCH] target/m68k: fix V flag for CC_OP_SUBx 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: Laurent Vivier , Richard Henderson Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" V flag for subtraction is: v = (res ^ src1) & (src1 ^ src2) (see COMPUTE_CCR() in target/m68k/helper.c) But gen_flush_flags() uses: v = (res ^ src2) & (src1 ^ src2) The problem has been found with the following program: .global _start _start: move.l #-2147483648,%d0 subq.l #1,%d0 jvc 1f move.l #1,%d1 move.l #1,%d0 trap #0 1: move.l #0,%d1 move.l #1,%d0 trap #0 It works fine (exit(1)) on real hardware, and with "-singlestep". "-singlestep" uses gen_helper_flush_flags(), whereas without "-singlestep", V flag is computed directly in gen_flush_flags(). This patch updates gen_flush_flags() to have the same result as with gen_helper_flush_flags(). Signed-off-by: Laurent Vivier Reviewed-by: Richard Henderson --- target/m68k/translate.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/target/m68k/translate.c b/target/m68k/translate.c index ad4d4ef..52653f6 100644 --- a/target/m68k/translate.c +++ b/target/m68k/translate.c @@ -565,7 +565,7 @@ static void gen_flush_flags(DisasContext *s) t1 = tcg_temp_new(); tcg_gen_add_i32(t0, QREG_CC_N, QREG_CC_V); gen_ext(t0, t0, s->cc_op - CC_OP_SUBB, 1); - tcg_gen_xor_i32(t1, QREG_CC_N, QREG_CC_V); + tcg_gen_xor_i32(t1, QREG_CC_N, t0); tcg_gen_xor_i32(QREG_CC_V, QREG_CC_V, t0); tcg_temp_free(t0); tcg_gen_and_i32(QREG_CC_V, QREG_CC_V, t1);