Technique for efficient multiplication of vectors of complex numbers

Disclosed is processing circuitry to perform vector operations. The circuitry has an array storage that has storage elements to store data blocks to store a two-dimensional array of data blocks accessible to the processing circuitry when performing the vector operations. The instructions to perform the operations include a complex valued outer product instruction specifying a first source operand, a second source operand, and a destination operand. Each of the source operands are vector operand comprising a set of source data elements, each source data element is a complex number formed of a real part and an imaginary part. The destination operand identifies a two-dimensional array of data blocks within the array storage. The processing circuitry is responsive to the complex valued outer product instruction to perform such an operation using the source data elements of the source operands in order to generate a set of result data elements. Each result data element is a complex number formed of a real part and an imaginary part, and each part of each result data element is associated with one of the data blocks in the given two-dimensional array of data blocks and is used to update a value of that associated data block.