From patchwork Mon Sep 28 13:51:27 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chen Gang X-Patchwork-Id: 523586 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 457CB1401CD for ; Tue, 29 Sep 2015 05:57:03 +1000 (AEST) Received: from localhost ([::1]:40544 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZgeXl-00018T-7K for incoming@patchwork.ozlabs.org; Mon, 28 Sep 2015 15:57:01 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51141) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZgYqX-0001ZA-Ej for qemu-devel@nongnu.org; Mon, 28 Sep 2015 09:52:02 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZgYqT-0002nr-HZ for qemu-devel@nongnu.org; Mon, 28 Sep 2015 09:52:01 -0400 Received: from smtpbg299.qq.com ([184.105.67.99]:57818) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZgYqT-0002lL-9W for qemu-devel@nongnu.org; Mon, 28 Sep 2015 09:51:57 -0400 X-QQ-mid: esmtp20t1443448292t868t13754 Received: from localhost.localdomain (unknown [223.72.67.50]) by esmtp4.qq.com (ESMTP) with id ; Mon, 28 Sep 2015 21:51:31 +0800 (CST) X-QQ-SSF: 01000000000000F0FH700F00002000H X-QQ-FEAT: jVc9qW+oM4sWma8kN0ij2qVX+4lPDytOUrXgnlAx7pZrX+nUG/pX8uPRseiuI j2H4PBLJkoMqtTT3FjNUo4L1H4Uok1B7ExDB09a8mSj7Ooyo+b2ft4k+d0cnG4AWBDJgytS CexnbdT1UIkKkgsokPjOpMx5mqPV9TvW/U6Z6LS8n1th/spSDulFL7E8X89RGj2Pmwu412Z gOvlKdi0gv5zasufyL+hNWr509QvHv9bvOi7ZtSPHPG9Rx0n15Xlb X-QQ-GoodBg: 0 X-QQ-CSender: gang.chen.5i5j@qq.com From: gang.chen.5i5j@gmail.com To: peter.maydell@linaro.org, rth@twiddle.net Date: Mon, 28 Sep 2015 21:51:27 +0800 Message-Id: <1443448287-4433-1-git-send-email-gang.chen.5i5j@gmail.com> X-Mailer: git-send-email 1.9.3 X-QQ-SENDSIZE: 520 X-QQ-FName: 04825A42FD3C4DF78DA13D0F1F5EBF19 X-QQ-LocalIP: 127.0.0.1 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.4.x X-Received-From: 184.105.67.99 Cc: cmetcalf@ezchip.com, qemu-devel@nongnu.org, xili_gchen_5257@hotmail.com, Chen Gang Subject: [Qemu-devel] [PATCH] target-tilegx: Check zero dest register for ld instructions 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 From: Chen Gang At present, qemu x86_64 host backend can not remove the related dummy instructions. Even the worse, sometimes, it will generate the incorrect instructions which will cause segment fault for prefetch_l3 instruction. Signed-off-by: Chen Gang --- target-tilegx/translate.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/target-tilegx/translate.c b/target-tilegx/translate.c index 86da6b5..7232361 100644 --- a/target-tilegx/translate.c +++ b/target-tilegx/translate.c @@ -620,7 +620,9 @@ static TileExcp gen_rr_opcode(DisasContext *dc, unsigned opext, memop = MO_TEQ; mnemonic = "ld"; do_load: - tcg_gen_qemu_ld_tl(tdest, tsrca, dc->mmuidx, memop); + if (dest != TILEGX_R_ZERO) { + tcg_gen_qemu_ld_tl(tdest, tsrca, dc->mmuidx, memop); + } break; case OE_RR_X1(LDNA): tcg_gen_andi_tl(tdest, tsrca, ~7); @@ -1987,8 +1989,10 @@ static TileExcp decode_y2(DisasContext *dc, tilegx_bundle_bits bundle) memop = MO_TEQ; mnemonic = "ld"; do_load: - tcg_gen_qemu_ld_tl(dest_gr(dc, srcbdest), load_gr(dc, srca), - dc->mmuidx, memop); + if (srcbdest != TILEGX_R_ZERO) { + tcg_gen_qemu_ld_tl(dest_gr(dc, srcbdest), load_gr(dc, srca), + dc->mmuidx, memop); + } qemu_log_mask(CPU_LOG_TB_IN_ASM, "%s %s, %s", mnemonic, reg_names[srcbdest], reg_names[srca]); return TILEGX_EXCP_NONE;