IEEE_TRAP_ENABLE_DNO
#define FP_EX_DENORM IEEE_TRAP_ENABLE_DNO
fp |= (~sw & IEEE_TRAP_ENABLE_DNO) << 41;
sw |= (~fp >> 41) & IEEE_TRAP_ENABLE_DNO;
IEEE_TRAP_ENABLE_INE | IEEE_TRAP_ENABLE_DNO)
if (fex & IEEE_TRAP_ENABLE_DNO) si_code = FPE_FLTUND;
if (_fex & IEEE_TRAP_ENABLE_DNO) si_code = FPE_FLTUND;