From patchwork Tue Sep 6 03:42:56 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Gibson X-Patchwork-Id: 9315757 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 5888860760 for ; Tue, 6 Sep 2016 06:10:28 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2475128B24 for ; Tue, 6 Sep 2016 06:10:28 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 194E228B5C; Tue, 6 Sep 2016 06:10:28 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id D969028B24 for ; Tue, 6 Sep 2016 06:10:26 +0000 (UTC) Received: from localhost ([::1]:59023 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bh9aU-0006OK-3o for patchwork-qemu-devel@patchwork.kernel.org; Tue, 06 Sep 2016 02:10:26 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50089) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bh7GO-0003Bv-O7 for qemu-devel@nongnu.org; Mon, 05 Sep 2016 23:41:41 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bh7GG-0007ts-1f for qemu-devel@nongnu.org; Mon, 05 Sep 2016 23:41:32 -0400 Received: from ozlabs.org ([103.22.144.67]:55756) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bh7GF-0007l2-DW; Mon, 05 Sep 2016 23:41:23 -0400 Received: by ozlabs.org (Postfix, from userid 1007) id 3sSspB5rPDz9sD5; Tue, 6 Sep 2016 13:41:19 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gibson.dropbear.id.au; s=201602; t=1473133282; bh=vfDFVtUmXGjWvVtXTcAjo0FEJJlAmaToMl3HFn7wFwM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AQ5v+i2aS5I4T0DLIOHLAkn1uNZjUGx9fsLBoUPXi0Er7TzfQlO/ObHYT+g2D0nVb 3s/0zQ/vvg2PLC5vpqSy5pFim0pd6Q1SJJMGQWMJLzHLGtgFI28TCKJ0epetPguaBe jc+QE4++/mSxeHtbOJEsENqcr9q1VKz/SjDCgsAs= From: David Gibson To: peter.maydell@linaro.org Date: Tue, 6 Sep 2016 13:42:56 +1000 Message-Id: <1473133396-18940-47-git-send-email-david@gibson.dropbear.id.au> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1473133396-18940-1-git-send-email-david@gibson.dropbear.id.au> References: <1473133396-18940-1-git-send-email-david@gibson.dropbear.id.au> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 103.22.144.67 Subject: [Qemu-devel] [PULL 46/66] target-ppc: implement branch-less divw[o][.] 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: David Gibson , qemu-ppc@nongnu.org, agraf@suse.de, Nikunj A Dadhania , qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP From: Nikunj A Dadhania While implementing modulo instructions figured out that the implementation uses many branches. Change the logic to achieve the branch-less code. Undefined value is set to dividend in case of invalid input. Signed-off-by: Nikunj A Dadhania Reviewed-by: Richard Henderson Signed-off-by: David Gibson --- target-ppc/translate.c | 48 +++++++++++++++++++++++------------------------- 1 file changed, 23 insertions(+), 25 deletions(-) diff --git a/target-ppc/translate.c b/target-ppc/translate.c index 379d3d4..f69836d 100644 --- a/target-ppc/translate.c +++ b/target-ppc/translate.c @@ -1097,41 +1097,39 @@ static void gen_addpcis(DisasContext *ctx) static inline void gen_op_arith_divw(DisasContext *ctx, TCGv ret, TCGv arg1, TCGv arg2, int sign, int compute_ov) { - TCGLabel *l1 = gen_new_label(); - TCGLabel *l2 = gen_new_label(); - TCGv_i32 t0 = tcg_temp_local_new_i32(); - TCGv_i32 t1 = tcg_temp_local_new_i32(); + TCGv_i32 t0 = tcg_temp_new_i32(); + TCGv_i32 t1 = tcg_temp_new_i32(); + TCGv_i32 t2 = tcg_temp_new_i32(); + TCGv_i32 t3 = tcg_temp_new_i32(); tcg_gen_trunc_tl_i32(t0, arg1); tcg_gen_trunc_tl_i32(t1, arg2); - tcg_gen_brcondi_i32(TCG_COND_EQ, t1, 0, l1); - if (sign) { - TCGLabel *l3 = gen_new_label(); - tcg_gen_brcondi_i32(TCG_COND_NE, t1, -1, l3); - tcg_gen_brcondi_i32(TCG_COND_EQ, t0, INT32_MIN, l1); - gen_set_label(l3); - tcg_gen_div_i32(t0, t0, t1); - } else { - tcg_gen_divu_i32(t0, t0, t1); - } - if (compute_ov) { - tcg_gen_movi_tl(cpu_ov, 0); - } - tcg_gen_br(l2); - gen_set_label(l1); if (sign) { - tcg_gen_sari_i32(t0, t0, 31); + tcg_gen_setcondi_i32(TCG_COND_EQ, t2, t0, INT_MIN); + tcg_gen_setcondi_i32(TCG_COND_EQ, t3, t1, -1); + tcg_gen_and_i32(t2, t2, t3); + tcg_gen_setcondi_i32(TCG_COND_EQ, t3, t1, 0); + tcg_gen_or_i32(t2, t2, t3); + tcg_gen_movi_i32(t3, 0); + tcg_gen_movcond_i32(TCG_COND_NE, t1, t2, t3, t2, t1); + tcg_gen_div_i32(t3, t0, t1); + tcg_gen_extu_i32_tl(ret, t3); } else { - tcg_gen_movi_i32(t0, 0); + tcg_gen_setcondi_i32(TCG_COND_EQ, t2, t1, 0); + tcg_gen_movi_i32(t3, 0); + tcg_gen_movcond_i32(TCG_COND_NE, t1, t2, t3, t2, t1); + tcg_gen_divu_i32(t3, t0, t1); + tcg_gen_extu_i32_tl(ret, t3); } if (compute_ov) { - tcg_gen_movi_tl(cpu_ov, 1); - tcg_gen_movi_tl(cpu_so, 1); + tcg_gen_extu_i32_tl(cpu_ov, t2); + tcg_gen_or_tl(cpu_so, cpu_so, cpu_ov); } - gen_set_label(l2); - tcg_gen_extu_i32_tl(ret, t0); tcg_temp_free_i32(t0); tcg_temp_free_i32(t1); + tcg_temp_free_i32(t2); + tcg_temp_free_i32(t3); + if (unlikely(Rc(ctx->opcode) != 0)) gen_set_Rc0(ctx, ret); }