Editing Endianness (section)

=== Calculation order ===

Some operations in [[positional number system]]s have a natural or preferred order in which the elementary steps are to be executed. This order may affect their performance on small-scale byte-addressable processors and [[microcontroller]]s. However, high-performance processors usually fetch multi-byte operands from memory in the same amount of time they would have fetched a single byte, so the complexity of the hardware is not affected by the byte ordering.

Addition, subtraction, and multiplication start at the least significant digit position and [[Adder (electronics)|propagate the carry]] to the subsequent more significant position. On most systems, the address of a multi-byte value is the address of its first byte (the byte with the lowest address). The implementation of these operations is marginally simpler using little-endian machines where this first byte contains the least significant digit.

Comparison and division start at the most significant digit and propagate a possible carry to the subsequent less significant digits. For fixed-length numerical values (typically of length 1,2,4,8,16), the implementation of these operations is marginally simpler on big-endian machines.

Some big-endian processors (e.g. the IBM System/360 and its successors) contain hardware instructions for lexicographically comparing varying length [[character string]]s.

The normal data transport by an [[Assignment (computer science)|assignment]] statement is in principle independent of the endianness of the processor.