The _udiv128 intrinsic divides a 128-bit unsigned integer by a 64-bit unsigned integer. The return value holds the quotient, and the intrinsic returns the remainder through a pointer parameter. _udiv128 is Microsoft-specific.

unsigned __int64 _udiv128(
   unsigned __int64 highDividend,
   unsigned __int64 lowDividend,
   unsigned __int64 divisor,
   unsigned __int64 *remainder
);

highDividend
[in] The high 64 bits of the dividend.

lowDividend
[in] The low 64 bits of the dividend.

divisor
[in] The 64-bit integer to divide by.

remainder
[out] The 64-bit integer bits of the remainder.

The 64 bits of the quotient.

Pass the upper 64 bits of the 128-bit dividend in highDividend, and the lower 64 bits in lowDividend. The intrinsic divides this value by divisor. It stores the remainder in the 64-bit unsigned integer pointed to by remainder, and returns the 64 bits of the quotient.

The _udiv128 intrinsic is available starting in Visual Studio 2019 RTM.

_div128
Compiler intrinsics