ESW
if(ha > ESW(MAX_EXP/2-12)) { /* a>2**(MAX_EXP/2-12) */
if(ha >= ESW(MAX_EXP)) { /* Inf or NaN */
if (hb >= ESW(MAX_EXP) && manh == LDBL_NBIT && manl == 0) w = b;
if(hb < ESW(-(MAX_EXP/2-12))) { /* b < 2**-(MAX_EXP/2-12) */
SET_HIGH_WORD(t1,ESW(MAX_EXP-2)); /* t1=2^(MAX_EXP-2) */