From mboxrd@z Thu Jan 1 00:00:00 1970 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 Date: Fri, 7 Jan 2011 09:26:25 +0000 Message-Id: <1294392387-24300-3-git-send-email-peter.maydell@linaro.org> In-Reply-To: <1294392387-24300-1-git-send-email-peter.maydell@linaro.org> References: <1294392387-24300-1-git-send-email-peter.maydell@linaro.org> Subject: [Qemu-devel] [PATCH 2/4] target-arm: Fix implementation of VRSQRTS List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@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 --- 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. */ -- 1.6.3.3