mask_fcr31_x
unsigned long fcr31 = mask_fcr31_x(next->thread.fpu.fcr31); \
*fcr31 = res = mask_fcr31_x(current->thread.fpu.fcr31);
fcr31 = mask_fcr31_x(current->thread.fpu.fcr31);
fcr31 = mask_fcr31_x(current->thread.fpu.fcr31);
write_32bit_cp1_register(CP1_STATUS, fcr31 & ~mask_fcr31_x(fcr31));
fcr31 = mask_fcr31_x(current->thread.fpu.fcr31);