From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41109) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YGUjo-0003gT-QQ for qemu-devel@nongnu.org; Wed, 28 Jan 2015 10:41:05 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YGUjk-0007i2-9A for qemu-devel@nongnu.org; Wed, 28 Jan 2015 10:41:04 -0500 Received: from mail-pa0-x235.google.com ([2607:f8b0:400e:c03::235]:55740) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YGUjj-0007hb-TV for qemu-devel@nongnu.org; Wed, 28 Jan 2015 10:41:00 -0500 Received: by mail-pa0-f53.google.com with SMTP id kx10so26552354pab.12 for ; Wed, 28 Jan 2015 07:40:59 -0800 (PST) From: Xiangyu Hu Date: Wed, 28 Jan 2015 15:40:50 +0000 Message-Id: <1422459650-12490-1-git-send-email-libhu.so@gmail.com> Subject: [Qemu-devel] [PATCH] Fix FMULX not squashing denormalized inputs when FZ is set. List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: peter.maydell@linaro.org, Xiangyu Hu While FMULX returns a 2.0f float when two operators are infinity and zero, those operators should be unpacked from raw inputs first. Inconsistent cases would occur when operators are denormalized floats in flush-to-zero mode. A wrong codepath will be entered and 2.0f will not be returned without this patch. Fix by checking whether inputs need to be flushed before running into different codepaths. Signed-off-by: Xiangyu Hu --- target-arm/helper-a64.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/target-arm/helper-a64.c b/target-arm/helper-a64.c index 81066ca..ebd9247 100644 --- a/target-arm/helper-a64.c +++ b/target-arm/helper-a64.c @@ -135,6 +135,9 @@ float32 HELPER(vfp_mulxs)(float32 a, float32 b, void *fpstp) { float_status *fpst = fpstp; + a = float32_squash_input_denormal(a, fpst); + b = float32_squash_input_denormal(b, fpst); + if ((float32_is_zero(a) && float32_is_infinity(b)) || (float32_is_infinity(a) && float32_is_zero(b))) { /* 2.0 with the sign bit set to sign(A) XOR sign(B) */ @@ -148,6 +151,9 @@ float64 HELPER(vfp_mulxd)(float64 a, float64 b, void *fpstp) { float_status *fpst = fpstp; + a = float64_squash_input_denormal(a, fpst); + b = float64_squash_input_denormal(b, fpst); + if ((float64_is_zero(a) && float64_is_infinity(b)) || (float64_is_infinity(a) && float64_is_zero(b))) { /* 2.0 with the sign bit set to sign(A) XOR sign(B) */ -- 1.9.1