A single instruction, multiple data (SIMD) processor including a plurality of addressing register sets, used to flexibly calculate effective operand source and destination memory addresses is disclosed. Two or more address generators calculate effective addresses using the register sets. Each register set includes a pointer register, and a scale register. An address generator forms effective addresses from a selected register set's pointer register and scale register; and an offset. For example, the effective memory address may be formed by multiplying the scale value by an offset value and summing the pointer and the scale value multiplied by the offset value.