Multiple-outer-product instruction

A multiple-outer-product instruction specifies multiple first source vector operands, at least one second source vector operand and correlation information associated with the second source vector operand. Each vector operand comprises multiple data elements. The correlation information indicates, for each data element of a given second source vector operand, a corresponding first source vector operand. In response to the multiple-outer product instruction, an outer product operation between each first source vector operand, and a subset of data elements of the second source vector operand(s). The processing circuitry selects, for each data element of the second source vector operand, a corresponding first source vector operand to be used when performing the associated outer product operation, in dependence on the correlation information. The results of the separate multiply outer product operations may be added to create a single result matrix. The input data may be weights or matrix activations in an artificial neural network.