Methods and apparatuses for performing arithmetic operations efficiently and quickly are described. Such arithmetic operations include, but are not limited to, multiplying 2N bit integers, multiplying multiple N-bit integers simultaneously, multiplying 2N bit complex numbers, and other multiplication operations involving coefficients, complex numbers, and complex conjugate numbers.

A data processing apparatus and method are provided for performing rearrangement operations. The data processing apparatus has a register data store with a plurality of registers, each register storing a plurality of data elements. Processing circuitry is responsive to control signals to perform processing operations on the data elements. An instruction decoder is responsive to at least one but no more than N rearrangement instructions, where N is an odd plural number, to generate control signals to control the processing circuitry to perform a rearrangement process at least equivalent to: obtaining as source data elements the data elements stored in N registers of said register data store as identified by the at least one re-arrangement instruction; performing a rearrangement operation to rearrange the source data elements between a regular N-way interleaved order and a de-interleaved order in order to produce a sequence of result data elements; and outputting the sequence of result data elements for storing in the register data store. This provides a particularly efficient technique for performing N-way interleave and de-interleave operations, where N is an odd number, resulting in high performance, low energy consumption, and reduced register use when compared with known prior art techniques.

A dot product array comprises dot product circuits each to process a respective pair of first and second input vectors to generate a respective dot product result. In a real number mode, each dot product result and vector element represents a respective real number. In a hypercomplex number mode, an input vector manipulation is applied to at least one of the first/second input vectors to be supplied to each dot product circuit, to cause the dot product array to generate hypercomplex dot product results each indicating a sum of hypercomplex products of corresponding pairs of hypercomplex numbers. In the hypercomplex number mode, respective subsets of elements of the first/second input vectors represent respective hypercomplex numbers, for which respective components are represented by different elements of the subset, and each hypercomplex dot product result comprises components represented by the dot product results generated by a corresponding group of at least two dot product circuits.

An embodiment of the invention is a processor including execution circuitry to calculate, in response to a decoded instruction, a result of a complex multiplication of a first complex number and a second complex number. The calculation includes a first operation to calculate a first term of a real component of the result and a first term of the imaginary component of the result. The calculation also includes a second operation to calculate a second term of the real component of the result and a second term of the imaginary component of the result. The processor also includes a decoder, a first source register, and a second source register. The decoder is to decode an instruction to generate the decoded instruction. The first source register is to provide the first complex number and the second source register is to provide the second complex number.