From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41838) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1e32ld-0002cy-Po for qemu-devel@nongnu.org; Fri, 13 Oct 2017 12:24:59 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1e32lZ-0006bL-8Z for qemu-devel@nongnu.org; Fri, 13 Oct 2017 12:24:57 -0400 Received: from mail-wr0-x233.google.com ([2a00:1450:400c:c0c::233]:54683) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1e32lZ-0006ak-2N for qemu-devel@nongnu.org; Fri, 13 Oct 2017 12:24:53 -0400 Received: by mail-wr0-x233.google.com with SMTP id o44so1427033wrf.11 for ; Fri, 13 Oct 2017 09:24:52 -0700 (PDT) From: =?UTF-8?q?Alex=20Benn=C3=A9e?= Date: Fri, 13 Oct 2017 17:24:17 +0100 Message-Id: <20171013162438.32458-10-alex.bennee@linaro.org> In-Reply-To: <20171013162438.32458-1-alex.bennee@linaro.org> References: <20171013162438.32458-1-alex.bennee@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Subject: [Qemu-devel] [RFC PATCH 09/30] softfloat: propagate signalling NaNs in MINMAX List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: richard.henderson@linaro.org Cc: peter.maydell@linaro.org, qemu-devel@nongnu.org, qemu-arm@nongnu.org, =?UTF-8?q?Alex=20Benn=C3=A9e?= , Aurelien Jarno While a comparison between a QNaN and a number will return the number it is not the same with a signaling NaN. In this case the SNaN will "win" and after potentially raising an exception it will be quietened. Signed-off-by: Alex Bennée --- fpu/softfloat.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/fpu/softfloat.c b/fpu/softfloat.c index 013b223947..6ab4b39c09 100644 --- a/fpu/softfloat.c +++ b/fpu/softfloat.c @@ -7684,6 +7684,7 @@ int float128_compare_quiet(float128 a, float128 b, float_status *status) * minnum() and maxnum() functions. These are similar to the min() * and max() functions but if one of the arguments is a QNaN and * the other is numerical then the numerical argument is returned. + * SNaNs will get quietened before being returned. * minnum() and maxnum correspond to the IEEE 754-2008 minNum() * and maxNum() operations. min() and max() are the typical min/max * semantics provided by many CPUs which predate that specification. @@ -7704,11 +7705,14 @@ static inline float ## s float ## s ## _minmax(float ## s a, float ## s b, \ if (float ## s ## _is_any_nan(a) || \ float ## s ## _is_any_nan(b)) { \ if (isieee) { \ - if (float ## s ## _is_quiet_nan(a, status) && \ + if (float ## s ## _is_signaling_nan(a, status) || \ + float ## s ## _is_signaling_nan(b, status)) { \ + propagateFloat ## s ## NaN(a, b, status); \ + } else if (float ## s ## _is_quiet_nan(a, status) && \ !float ## s ##_is_any_nan(b)) { \ return b; \ } else if (float ## s ## _is_quiet_nan(b, status) && \ - !float ## s ## _is_any_nan(a)) { \ + !float ## s ## _is_any_nan(a)) { \ return a; \ } \ } \ -- 2.14.1