Register transfer language

In computer science, register transfer language (RTL) is a kind of intermediate representation (IR) that is very close to assembly language, such as that which is used in a compiler. It is used to describe data flow at the register-transfer level of an architecture. Academic papers and textbooks often use a form of RTL as an architecture-neutral assembly language. RTL is used as the name of a specific intermediate representation in several compilers, including the Gnu Compiler Collection (GCC), Zephyr, and the European compiler projects CerCo and CompCert.In GCC, RTL is generated from the GIMPLE representation, transformed by various passes in the GCC 'middle-end', and then converted to assembly language.The idea behind RTL was first described in:Davidson and Fraser; The Design and Application of a Retargetable Peephole Optimizer; ToPLaS v2(2) 191-202 (April 1980)