I am currently working on implementing the decoupled-lookback in Futhark, as my master thesis. The development is under the branch `onepassscan`. It is still missing some features, like it cannot do map'o'scan, meaning include the map function in the scan optimization. It is likely that the implementation will only be used for Nvidia, since the cache guarentees only are prommised to work for Nvidia.

The current version of Futhark is using the reduce-then-scan strategy.