Instruction selection

In computer science, instruction selection is the stage of a compiler backend that transforms its middle-level intermediate representation (IR) into a low-level IR where each operation directly corresponds to an instruction available on the target machine. In a typical compiler, instruction selection precedes both instruction scheduling and register allocation; hence its output IR has an infinite set of pseudo-registers (often known as temporaries) and may still be – and typically is – subject to peephole optimization. Otherwise, it closely resembles the target machine code, bytecode, or assembly language. In computer science, instruction selection is the stage of a compiler backend that transforms its middle-level intermediate representation (IR) into a low-level IR where each operation directly corresponds to an instruction available on the target machine. In a typical compiler, instruction selection precedes both instruction scheduling and register allocation; hence its output IR has an infinite set of pseudo-registers (often known as temporaries) and may still be – and typically is – subject to peephole optimization. Otherwise, it closely resembles the target machine code, bytecode, or assembly language.