public static UIntT Decrease(UIntT value_lo, IntT value_hi, out IntT result_hi)
{
return(DecreaseSigned(value_lo, value_hi, out result_hi));
}
public static UIntT Increase(UIntT value_lo, UIntT value_hi, out UIntT result_hi)
{
return(IncreaseUnsigned(value_lo, value_hi, out result_hi));
}
public static UIntT ShiftRight(UIntT low, IntT high, int count, out IntT highResult)
{
return(ShiftRightSigned(low, high, count, out highResult));
}
public static UIntT ShiftRight(UIntT low, UIntT high, out UIntT highResult)
{
return(ShiftRightUnsigned(low, high, out highResult));
}
public static UIntT mpn_preinv_divrem_1(Span <UIntT> q, ReadOnlySpan <UIntT> a, UIntT d_unnorm, UIntT dinv, int shift)
{
unchecked {
UIntT r;
int i;
UIntT d;
var xsize = q.Length;
Assert(xsize >= 0);
var size = a.Length;
Assert(size >= 1);
Assert(d_unnorm != 0);
#if true || ASSERTIONS_FULL
mpn_preinv_divrem_1_assert_1(d_unnorm, dinv, shift);
#endif
/* FIXME: What's the correct overlap rule when xsize!=0? */
Assert(IsSameOrSeparate(q.Slice(xsize), a));
var ahigh = a[size - 1];
d = d_unnorm << shift;
var q_index = (size + xsize - 1); /* dest high limb */
if (shift == 0)
{
/* High quotient limb is 0 or 1, and skip a divide step. */
r = ahigh;
var qhigh = (r >= d ? (UIntT)1 : 0);
r = (r >= d ? r - d : r);
q[q_index--] = qhigh;
size--;
for (i = size - 1; i >= 0; i--)
{
q[q_index] = DoubleArithmetic.BigDivRemByInverseInternal(a[i], r, dinv, d, out r);
q_index--;
}
}
else
{
UIntT n1, n0;
r = 0;
if (ahigh < d_unnorm)
{
r = ahigh << shift;
q[q_index--] = 0;
size--;
if (size == 0)
{
goto L_1;
}
}
n1 = a[size - 1];
r |= n1 >> (-shift /* sizeof(UIntT) - shift */);
for (i = size - 2; i >= 0; i--)
{
Assert(r < d);
n0 = a[i];
q[q_index] = DoubleArithmetic.BigDivRemByInverseInternal((n1 << shift) | (n0 >> (-shift /* sizeof(UIntT) - shift */)), r, dinv, d, out r);
q_index--;
n1 = n0;
}
q[q_index] = DoubleArithmetic.BigDivRemByInverseInternal(n1 << shift, r, dinv, d, out r);
q_index--;
}
L_1 :;
for (i = 0; i < xsize; i++)
{
q[q_index] = DoubleArithmetic.BigDivRemByInverseInternal(_: default, r, dinv, d, out r);
