A compiler optimization for structure peeling an array of structures (AOS) into a structure of arrays (SOA) by which a pointer to an array in the original program, is transformed into a tagged index that includes both an array index, and a memory identifier tagging the array index. Once processed by the compiler, each array index is identified by a respective memory identifier, hence if the program instructions call for redefining an array during run time, its array element can still be retrieved by referring to the memory identifier it is tagged with.