(EN) A data processing apparatus a method of operating a data processing apparatus a non-transitory computer readable storage medium and an instruction are provided. The instruction specifies a first source register and a second source register. In response to the instruction control signals are generated causing processing circuitry to perform a dot product operation. For this operation at least a first data element and a second data element are extracted from each of the first source register and the second source register such that then at least first data element pairs and second data element pairs are multiplied together. The dot product operation is performed independently in each of multiple intra-register lanes across each of the first source register and the second source register. A widening operation with a large density of operations per instruction is thus provided.