cpu_has_nan_legacy
#ifndef cpu_has_nan_legacy
if (!cpu_has_nan_legacy) {
mips_use_nan_legacy = !!cpu_has_nan_legacy;
mips_use_nan_legacy = !!cpu_has_nan_legacy;
mips_use_nan_2008 = !cpu_has_nan_legacy;
if (cpu_has_nan_legacy)