| Append |  | 
| AppendG | TODO Additional compiler enhancements:
 1) Partial Shuffle Elimination - Any full or aligned blocks could be directly output from the mappers
    to the result index. | 
| AppendGAlignedSP |  | 
| AppendM |  | 
| AppendR |  | 
| Binary | Lop to perform binary operation. | 
| BinaryM | Lop to perform binary operation. | 
| BinaryScalar | Lop to perform binary scalar operations. | 
| BinaryUAggChain |  | 
| CentralMoment | Lop to perform cross product operation | 
| Checkpoint | Lop for checkpoint operations. | 
| Compression |  | 
| CoVariance | Lop to compute covariance between two 1D matrices | 
| CSVReBlock | Lop to convert CSV data into SystemDS data format | 
| Ctable | Lop to perform ternary operation. | 
| CumulativeOffsetBinary |  | 
| CumulativePartialAggregate |  | 
| Data | Lop to represent data objects. | 
| DataGen | Defines a LOP that generates data. | 
| DeCompression |  | 
| DnnTransform |  | 
| Federated |  | 
| FunctionCallCP |  | 
| GroupedAggregate | Lop to perform grouped aggregates | 
| GroupedAggregateM | Lop to perform mr map-side grouped aggregates 
 (restriction: sum, w/o weights, ngroups), groups broadcasted | 
| LeftIndex |  | 
| Local |  | 
| Lop | Base class for all Lops. | 
| LopProperties |  | 
| MapMult |  | 
| MapMultChain |  | 
| MatMultCP |  | 
| MMCJ | Lop to perform cross product operation | 
| MMRJ | Lop to perform cross product operation | 
| MMTSJ | Lop to perform transpose-identity operation (t(X)%*%X or X%*%t(X)),
 used to represent CP and MR instruction but in case of MR there is
 an additional Aggregate at the reducers. | 
| MMZip | Lop to perform zip matrix multiplication | 
| Nary | Lop to perform an operation on a variable number of operands. | 
| OutputParameters | class to maintain output parameters for a lop. | 
| ParameterizedBuiltin | Defines a LOP for functions. | 
| PartialAggregate | Lop to perform a partial aggregation. | 
| PickByCount |  | 
| PMapMult |  | 
| PMMJ |  | 
| ReBlock | Lop to perform reblock operation | 
| RightIndex |  | 
| SortKeys |  | 
| SpoofFused |  | 
| Sql |  | 
| Ternary | Lop to perform Sum of a matrix with another matrix multiplied by Scalar. | 
| TernaryAggregate |  | 
| Transform |  | 
| UAggOuterChain | TODO Currently this lop only support the right hand side in distributed cache. | 
| Unary | Lop to perform following operations: with one operand -- NOT(A), ABS(A),
 SQRT(A), LOG(A) with two operands where one of them is a scalar -- H=H*i,
 H=H*5, EXP(A,2), LOG(A,2) | 
| UnaryCP |  | 
| WeightedCrossEntropy |  | 
| WeightedCrossEntropyR |  | 
| WeightedDivMM |  | 
| WeightedDivMMR |  | 
| WeightedSigmoid |  | 
| WeightedSigmoidR |  | 
| WeightedSquaredLoss |  | 
| WeightedSquaredLossR |  | 
| WeightedUnaryMM |  | 
| WeightedUnaryMMR |  |