--- zzzz-none-000/linux-3.10.107/arch/mips/math-emu/ieee754sp.c	2017-06-27 09:49:32.000000000 +0000
+++ vr9-7490-729/linux-3.10.107/arch/mips/math-emu/ieee754sp.c	2021-11-10 11:53:54.000000000 +0000
@@ -41,6 +41,8 @@
 int ieee754sp_issnan(ieee754sp x)
 {
 	assert(ieee754sp_isnan(x));
+	if (ieee754_csr.nan2008)
+		return !(SPMANT(x) & SP_MBIT(SP_MBITS-1));
 	return (SPMANT(x) & SP_MBIT(SP_MBITS-1));
 }