AddressModeV

Address mode V, designated as Vir, is a type of addressing mode used in computers. It is similar to address mode M, also known as Memory, but differs in the way memory locations are accessed.

In address mode M, memory locations are identified through a combination of base and index registers. By contrast, address mode V uses a base register and two index registers to access memory locations. This enables more complex addressing schemes and is often used in vector processing or graphics processing units (GPU).

The base register in address mode V holds the initial memory address, while the two index registers maintain offset values. These offset values are used to calculate the final memory address. The processor performs a series of arithmetic operations on the contents of the base register and the index registers to arrive at the correct memory address.

Address mode V is specifically utilized in vector operations where a large number of data elements need to be retrieved from memory. It simplifies the process of accessing such data by allowing the indexing to span any memory location. This makes it easier to perform complex operations like vector addition, dot products, or tree traversal on data stored in memory.

The use of address mode V in certain IBM mainframes and other computers requires the program to instruct the CPU to navigate across the address space this way when making virtual calls.