static void produce_digits_low(
limb_type *limbs, std::size_t limb_cnt,
fp_value_t<T> const &val, int32_t exp10, int32_t denom_shift,
uint8_t *m_out, std::size_t &m_len, int32_t &exp_out
) {
auto num(limbs);
auto bound(limbs + limb_cnt);
bool in_range(false);
if (Pow2) {
in_range = compare_sum_pow2<true>(
num, bound, denom_shift, limb_cnt
) >= 0;
} else {
if (val.m & 1)
in_range = compare_sum_pow2<false>(
num, bound, denom_shift, limb_cnt
) > 0;
else
in_range = compare_sum_pow2<false>(
num, bound, denom_shift, limb_cnt
) >= 0;
}
if (in_range)
++exp10;
else {
multiply_10(num, limb_cnt);
multiply_10(bound, limb_cnt);
}
m_len = 0;
while (true) {
limb_type digit(mod_pow2(num, limb_cnt, denom_shift));
int bd_test(0);
if (Pow2) {
bd_test |= compare(
num, bound, limb_cnt
) <= 0 ? 1 : 0;
bd_test |= compare_sum_pow2<true>(
num, bound, denom_shift, limb_cnt
) >= 0 ? 2 : 0;
} else {
if (val.m & 1) {
bd_test |= compare(
num, bound, limb_cnt
) < 0 ? 1 : 0;
bd_test |= compare_sum_pow2<false>(
num, bound, denom_shift,
limb_cnt
) > 0 ? 2 : 0;
} else {
bd_test |= compare(
num, bound, limb_cnt
) <= 0 ? 1 : 0;
bd_test |= compare_sum_pow2<false>(
num, bound, denom_shift,
limb_cnt
) >= 0 ? 2 : 0;
}
}
switch (bd_test) {
case 0:
m_out[m_len / 2] = m_len & 1
? m_out[m_len / 2] | (digit << 4)
: digit;
++m_len;
multiply_10(num, limb_cnt);
multiply_10(bound, limb_cnt);
break;
case 1:
m_out[m_len / 2] = m_len & 1
? m_out[m_len / 2] | (digit << 4)
: digit;
++m_len;
exp_out = exp10 - m_len;
return;
case 2:
++digit;
m_out[m_len / 2] = m_len & 1
? m_out[m_len / 2] | (digit << 4)
: digit;
++m_len;
exp_out = exp10 - m_len;
return;
case 3:
bd_test = compare_sum_pow2<false>(
num, num, denom_shift, limb_cnt
);
if ((bd_test > 0) || (!bd_test && (digit & 1)))
++digit;
m_out[m_len / 2] = m_len & 1
? m_out[m_len / 2] | (digit << 4)
: digit;
++m_len;
exp_out = exp10 - m_len;
return;
}
}
}
ll mod_pow2(ll x, ll n, ll mod){
if (n==0) return 1;
ll res = mod_pow2(x* x % mod, n / 2, mod);
if (n&1) res = res*x % mod;
return res;
}
