Only copy arrays, not e.g. accumulators.
Only copy arrays, not e.g. accumulators.

diku-dk/futhark,diku-dk/futhark,HIPERFIT/futhark,diku-dk/futhark,diku-dk/futhark,HIPERFIT/futhark,diku-dk/futhark,HIPERFIT/futhark