long double
expm1l(long double x)
{
union IEEEl2bits u, v;
long double fn, hx2_hi, hx2_lo, q, r, r1, r2, t, twomk, twopk, x_hi;
long double x_lo, x2, z;
long double x4;
int k, n, n2;
uint16_t hx, ix;
DOPRINT_START(&x);
/* Filter out exceptional cases. */
u.e = x;
hx = u.xbits.expsign;
ix = hx & 0x7fff;
if (ix >= BIAS + 6) { /* |x| >= 64 or x is NaN */
if (ix == BIAS + LDBL_MAX_EXP) {
if (hx & 0x8000) /* x is -Inf, -NaN or unsupported */
RETURNP(-1 / x - 1);
RETURNP(x + x); /* x is +Inf, +NaN or unsupported */
}
if (x > o_threshold)
RETURNP(huge * huge);
/*
* expm1l() never underflows, but it must avoid
* unrepresentable large negative exponents. We used a
* much smaller threshold for large |x| above than in
* expl() so as to handle not so large negative exponents
* in the same way as large ones here.
*/
if (hx & 0x8000) /* x <= -64 */
RETURN2P(tiny, -1); /* good for x < -65ln2 - eps */
}
ENTERI();
if (T1 < x && x < T2) {
if (ix < BIAS - 74) { /* |x| < 0x1p-74 (includes pseudos) */
/* x (rounded) with inexact if x != 0: */
RETURNPI(x == 0 ? x :
(0x1p100 * x + fabsl(x)) * 0x1p-100);
}
x2 = x * x;
x4 = x2 * x2;
q = x4 * (x2 * (x4 *
/*
* XXX the number of terms is no longer good for
* pairwise grouping of all except B3, and the
* grouping is no longer from highest down.
*/
(x2 * B12 + (x * B11 + B10)) +
(x2 * (x * B9 + B8) + (x * B7 + B6))) +
(x * B5 + B4.e)) + x2 * x * B3.e;
x_hi = (float)x;
x_lo = x - x_hi;
hx2_hi = x_hi * x_hi / 2;
hx2_lo = x_lo * (x + x_hi) / 2;
if (ix >= BIAS - 7)
RETURN2PI(hx2_hi + x_hi, hx2_lo + x_lo + q);
else
RETURN2PI(x, hx2_lo + q + hx2_hi);
}
/* Reduce x to (k*ln2 + endpoint[n2] + r1 + r2). */
/* Use a specialized rint() to get fn. Assume round-to-nearest. */
fn = x * INV_L + 0x1.8p63 - 0x1.8p63;
#if defined(HAVE_EFFICIENT_IRINTL)
n = irintl(fn);
#elif defined(HAVE_EFFICIENT_IRINT)
n = irint(fn);
#else
n = (int)fn;
#endif
n2 = (unsigned)n % INTERVALS;
k = n >> LOG2_INTERVALS;
r1 = x - fn * L1;
r2 = fn * -L2;
r = r1 + r2;
/* Prepare scale factor. */
v.e = 1;
v.xbits.expsign = BIAS + k;
twopk = v.e;
/*
* Evaluate lower terms of
* expl(endpoint[n2] + r1 + r2) = tbl[n2] * expl(r1 + r2).
*/
z = r * r;
q = r2 + z * (A2 + r * A3) + z * z * (A4 + r * A5) + z * z * z * A6;
t = (long double)tbl[n2].lo + tbl[n2].hi;
if (k == 0) {
t = SUM2P(tbl[n2].hi - 1, tbl[n2].lo * (r1 + 1) + t * q +
tbl[n2].hi * r1);
RETURNI(t);
}
if (k == -1) {
t = SUM2P(tbl[n2].hi - 2, tbl[n2].lo * (r1 + 1) + t * q +
tbl[n2].hi * r1);
RETURNI(t / 2);
}
if (k < -7) {
t = SUM2P(tbl[n2].hi, tbl[n2].lo + t * (q + r1));
RETURNI(t * twopk - 1);
}
if (k > 2 * LDBL_MANT_DIG - 1) {
t = SUM2P(tbl[n2].hi, tbl[n2].lo + t * (q + r1));
if (k == LDBL_MAX_EXP)
RETURNI(t * 2 * 0x1p16383L - 1);
RETURNI(t * twopk - 1);
}
v.xbits.expsign = BIAS - k;
twomk = v.e;
if (k > LDBL_MANT_DIG - 1)
t = SUM2P(tbl[n2].hi, tbl[n2].lo - twomk + t * (q + r1));
else
t = SUM2P(tbl[n2].hi - twomk, tbl[n2].lo + t * (q + r1));
RETURNI(t * twopk);
}
long double
expm1l(long double x)
{
union IEEEl2bits u, v;
long double hx2_hi, hx2_lo, q, r, r1, t, twomk, twopk, x_hi;
long double x_lo, x2;
double dr, dx, fn, r2;
int k, n, n2;
uint16_t hx, ix;
DOPRINT_START(&x);
/* Filter out exceptional cases. */
u.e = x;
hx = u.xbits.expsign;
ix = hx & 0x7fff;
if (ix >= BIAS + 7) { /* |x| >= 128 or x is NaN */
if (ix == BIAS + LDBL_MAX_EXP) {
if (hx & 0x8000) /* x is -Inf or -NaN */
RETURNP(-1 / x - 1);
RETURNP(x + x); /* x is +Inf or +NaN */
}
if (x > o_threshold)
RETURNP(huge * huge);
/*
* expm1l() never underflows, but it must avoid
* unrepresentable large negative exponents. We used a
* much smaller threshold for large |x| above than in
* expl() so as to handle not so large negative exponents
* in the same way as large ones here.
*/
if (hx & 0x8000) /* x <= -128 */
RETURN2P(tiny, -1); /* good for x < -114ln2 - eps */
}
ENTERI();
if (T1 < x && x < T2) {
x2 = x * x;
dx = x;
if (x < T3) {
if (ix < BIAS - 113) { /* |x| < 0x1p-113 */
/* x (rounded) with inexact if x != 0: */
RETURNPI(x == 0 ? x :
(0x1p200 * x + fabsl(x)) * 0x1p-200);
}
q = x * x2 * C3 + x2 * x2 * (C4 + x * (C5 + x * (C6 +
x * (C7 + x * (C8 + x * (C9 + x * (C10 +
x * (C11 + x * (C12 + x * (C13 +
dx * (C14 + dx * (C15 + dx * (C16 +
dx * (C17 + dx * C18))))))))))))));
} else {
q = x * x2 * D3 + x2 * x2 * (D4 + x * (D5 + x * (D6 +
x * (D7 + x * (D8 + x * (D9 + x * (D10 +
x * (D11 + x * (D12 + x * (D13 +
dx * (D14 + dx * (D15 + dx * (D16 +
dx * D17)))))))))))));
}
x_hi = (float)x;
x_lo = x - x_hi;
hx2_hi = x_hi * x_hi / 2;
hx2_lo = x_lo * (x + x_hi) / 2;
if (ix >= BIAS - 7)
RETURN2PI(hx2_hi + x_hi, hx2_lo + x_lo + q);
else
RETURN2PI(x, hx2_lo + q + hx2_hi);
}
/* Reduce x to (k*ln2 + endpoint[n2] + r1 + r2). */
/* Use a specialized rint() to get fn. Assume round-to-nearest. */
fn = (double)x * INV_L + 0x1.8p52 - 0x1.8p52;
#if defined(HAVE_EFFICIENT_IRINT)
n = irint(fn);
#else
n = (int)fn;
#endif
n2 = (unsigned)n % INTERVALS;
k = n >> LOG2_INTERVALS;
r1 = x - fn * L1;
r2 = fn * -L2;
r = r1 + r2;
/* Prepare scale factor. */
v.e = 1;
v.xbits.expsign = BIAS + k;
twopk = v.e;
/*
* Evaluate lower terms of
* expl(endpoint[n2] + r1 + r2) = tbl[n2] * expl(r1 + r2).
*/
dr = r;
q = r2 + r * r * (A2 + r * (A3 + r * (A4 + r * (A5 + r * (A6 +
dr * (A7 + dr * (A8 + dr * (A9 + dr * A10))))))));
t = tbl[n2].lo + tbl[n2].hi;
if (k == 0) {
t = SUM2P(tbl[n2].hi - 1, tbl[n2].lo * (r1 + 1) + t * q +
tbl[n2].hi * r1);
RETURNI(t);
}
if (k == -1) {
t = SUM2P(tbl[n2].hi - 2, tbl[n2].lo * (r1 + 1) + t * q +
tbl[n2].hi * r1);
RETURNI(t / 2);
}
if (k < -7) {
t = SUM2P(tbl[n2].hi, tbl[n2].lo + t * (q + r1));
RETURNI(t * twopk - 1);
}
if (k > 2 * LDBL_MANT_DIG - 1) {
t = SUM2P(tbl[n2].hi, tbl[n2].lo + t * (q + r1));
if (k == LDBL_MAX_EXP)
RETURNI(t * 2 * 0x1p16383L - 1);
RETURNI(t * twopk - 1);
}
v.xbits.expsign = BIAS - k;
twomk = v.e;
if (k > LDBL_MANT_DIG - 1)
t = SUM2P(tbl[n2].hi, tbl[n2].lo - twomk + t * (q + r1));
else
t = SUM2P(tbl[n2].hi - twomk, tbl[n2].lo + t * (q + r1));
RETURNI(t * twopk);
}
