long double
expl(long double x)
{
union IEEEl2bits u;
long double hi, lo, t, twopk;
int k;
uint16_t hx, ix;
DOPRINT_START(&x);
/* Filter out exceptional cases. */
u.e = x;
hx = u.xbits.expsign;
ix = hx & 0x7fff;
if (ix >= BIAS + 13) { /* |x| >= 8192 or x is NaN */
if (ix == BIAS + LDBL_MAX_EXP) {
if (hx & 0x8000) /* x is -Inf, -NaN or unsupported */
RETURNP(-1 / x);
RETURNP(x + x); /* x is +Inf, +NaN or unsupported */
}
if (x > o_threshold)
RETURNP(huge * huge);
if (x < u_threshold)
RETURNP(tiny * tiny);
} else if (ix < BIAS - 75) { /* |x| < 0x1p-75 (includes pseudos) */
RETURN2P(1, x); /* 1 with inexact iff x != 0 */
}
ENTERI();
twopk = 1;
__k_expl(x, &hi, &lo, &k);
t = SUM2P(hi, lo);
/* Scale by 2**k. */
if (k >= LDBL_MIN_EXP) {
if (k == LDBL_MAX_EXP)
RETURNI(t * 2 * 0x1p16383L);
SET_LDBL_EXPSIGN(twopk, BIAS + k);
RETURNI(t * twopk);
} else {
SET_LDBL_EXPSIGN(twopk, BIAS + k + 10000);
RETURNI(t * twopk * twom10000);
}
}
long double
atanhl(long double x)
{
long double t;
uint16_t hx, ix;
ENTERI();
GET_LDBL_EXPSIGN(hx, x);
ix = hx & 0x7fff;
if (ix >= 0x3fff) /* |x| >= 1, or NaN or misnormal */
RETURNI(fabsl(x) == 1 ? x / zero : (x - x) / (x - x));
if (ix < BIAS + EXP_TINY && (huge + x) > zero)
RETURNI(x); /* x is tiny */
SET_LDBL_EXPSIGN(x, ix);
if (ix < 0x3ffe) { /* |x| < 0.5, or misnormal */
t = x+x;
t = 0.5*log1pl(t+t*x/(one-x));
} else
t = 0.5*log1pl((x+x)/(one-x));
RETURNI((hx & 0x8000) == 0 ? t : -t);
}
