Branch_(computer_science)

For other uses, see Branch (disambiguation).

A branch (or jump on some computer architectures, such as the PDP-8 and Intel x86) is a point in a computer program where the flow of control is altered. The term branch is usually used when referring to a program written in machine code or assembly language; in a high-level programming language, branches usually take the form of conditional statements, subroutine calls or GOTO statements. An instruction that causes a branch, a branch instruction, can be taken or not taken: if a branch is not taken, the flow of control is unchanged and the next instruction to be executed is the instruction immediately following the current instruction in memory; if taken, the next instruction to be executed is an instruction at some other place in memory. There are two usual forms of branch instruction: a conditional branch that can be either taken or not taken, depending on a condition such as a CPU flag, and an unconditional branch which is always taken.

Examples

An unconditional branch in Intel assembly language:

jmp 0x00100000

A conditional branch in Intel assembly language:

jz 0x00100000

See also

• Control flow
• Branch delay slot
• Branch predictor
• Branch table
• Indirect branch
• Instruction pipeline
• Spaghetti code

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