1. A method of performing delta decoding on packed data elements of a source and storing the results in packed data elements of a destination using a single vector packed delta decode instruction, the method comprising the steps of: executing, in execution resources of a processor core, a decoded vector packed delta decode instruction that includes a source operand and a destination operand each having a plurality of packed data elements to calculate for each packed data element position of the source operand a value that comprises a packed data element of that packed data element position and all packed data elements of packed data element positions that are of lesser significance; and for each calculated value, storing the value into a packed data element position of the destination operand that corresponds to the packed data element position of the source operand.