Intermediate Representation (IR)

• Some form of bytecode that represents an abstract but (usually) optimised version of a program
• This bytecode is then typically compiled or interpreted by an IR interpreter to the specific computer’s Instruction Set Architecture

Examples

• .NET and the JVM are virtual machines that take an IR (“Common Intermediate Language” and “Java Bytecode” respectively) and interpret it for the host system
• llvm takes an intermediate representation generated by clang and compiles a program for a given host architecture