From patchwork Fri Jan 7 09:26:25 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Maydell X-Patchwork-Id: 77860 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [199.232.76.165]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 22CBEB70B3 for ; Fri, 7 Jan 2011 20:28:23 +1100 (EST) Received: from localhost ([127.0.0.1]:47239 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Pb8cO-00066A-7u for incoming@patchwork.ozlabs.org; Fri, 07 Jan 2011 04:28:20 -0500 Received: from [140.186.70.92] (port=43468 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Pb8ac-00061m-N0 for qemu-devel@nongnu.org; Fri, 07 Jan 2011 04:26:32 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Pb8ab-0005sv-GM for qemu-devel@nongnu.org; Fri, 07 Jan 2011 04:26:30 -0500 Received: from mnementh.archaic.org.uk ([81.2.115.146]:47395) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Pb8ab-0005sS-6m for qemu-devel@nongnu.org; Fri, 07 Jan 2011 04:26:29 -0500 Received: from pm215 by mnementh.archaic.org.uk with local (Exim 4.69) (envelope-from ) id 1Pb8aZ-0006KQ-3l for qemu-devel@nongnu.org; Fri, 07 Jan 2011 09:26:27 +0000 From: Peter Maydell To: qemu-devel@nongnu.org Date: Fri, 7 Jan 2011 09:26:25 +0000 Message-Id: <1294392387-24300-3-git-send-email-peter.maydell@linaro.org> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1294392387-24300-1-git-send-email-peter.maydell@linaro.org> References: <1294392387-24300-1-git-send-email-peter.maydell@linaro.org> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 2) Subject: [Qemu-devel] [PATCH 2/4] target-arm: Fix implementation of VRSQRTS X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org The implementation of the ARM VRSQRTS instruction (which calculates (3 - op1 * op2) / 2) was missing the division operation. It also did not handle the special cases of (0,inf) and (inf,0). Signed-off-by: Peter Maydell Reviewed-by: Aurelien Jarno --- target-arm/helper.c | 10 +++++++++- 1 files changed, 9 insertions(+), 1 deletions(-) diff --git a/target-arm/helper.c b/target-arm/helper.c index 705b99f..ac47de0 100644 --- a/target-arm/helper.c +++ b/target-arm/helper.c @@ -2612,8 +2612,16 @@ float32 HELPER(recps_f32)(float32 a, float32 b, CPUState *env) float32 HELPER(rsqrts_f32)(float32 a, float32 b, CPUState *env) { float_status *s = &env->vfp.fp_status; + float32 two = int32_to_float32(2, s); float32 three = int32_to_float32(3, s); - return float32_sub(three, float32_mul(a, b, s), s); + float32 product; + if ((float32_is_infinity(a) && float32_is_zero_or_denormal(b)) || + (float32_is_infinity(b) && float32_is_zero_or_denormal(a))) { + product = float32_zero; + } else { + product = float32_mul(a, b, s); + } + return float32_div(float32_sub(three, product, s), two, s); } /* NEON helpers. */