java.lang.Object
- org.apache.sysds.hops.rewrite.HopRewriteRule
- - org.apache.sysds.hops.rewrite.RewriteRemoveUnnecessaryCasts

```
public class RewriteRemoveUnnecessaryCasts
extends HopRewriteRule
```
Rule: RemoveUnnecessaryCasts. For all value type casts check if they are really necessary. If both cast input and output type are the same, the cast itself is redundant. There are two use case where this can arise: (1) automatically inserted casts on function inlining (in case of unknown value types), and (2) explicit script-level value type casts, that might be redundant according to the read input data. The benefit of this rewrite is negligible for scalars. However, when we support matrices with different value types, those casts might refer to matrices and with that incur large costs.

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`Hop`	`rewriteHopDAG(Hop root, ProgramRewriteStatus state)`	Handle a predicate hop DAG with exactly one root.
`ArrayList<Hop>`	`rewriteHopDAGs(ArrayList<Hop> roots, ProgramRewriteStatus state)`	Handle a generic (last-level) hop DAG with multiple roots.

Class RewriteRemoveUnnecessaryCasts