Loads a 64-bit value from
m and sets lane
v to that value.
This intrinsic is provided for completeness and is equivalent to
u64x2_replace_lane::<L>(v, *m) (which doesn’t require
This intrinsic is unsafe because it takes a raw pointer as an argument, and the pointer must be valid to load 8 bytes from. Note that there is no alignment requirement on this pointer since this intrinsic performs a 1-aligned load.