Editing Addressing mode (section)

===Scaled===
    +------+-----+-----+-----+
    | load | reg | base|index|
    +------+-----+-----+-----+
 
    (Effective address = contents of specified base register + scaled contents of specified index register)

The base register could contain the start address of an array or [[vector data structure]], and the index could contain the offset of the one particular array element required.

This addressing mode dynamically scales the value in the index register to allow for the size of each array element, e.g. if the array elements are double precision floating-point numbers occupying 8 bytes each then the value in the index register is multiplied by 8 before being used in the effective address calculation. The scale factor is normally restricted to being a [[power of two]], so that [[bit shift|shifting]] rather than multiplication can be used.