Prototype:

i64 @__nv_umul64hi(i64 %x, i64 %y) 

Description:

Calculate the most significant 64 bits of the 128-bit product x * y, where x and y are 64-bit unsigned integers.

Returns:

Returns the most significant 64 bits of the product x * y.

Library Availability:

Compute 2.0: Yes

Compute 3.0: Yes

Compute 3.5: Yes