The Free On-line Dictionary of Computing (30 December 2018):
Register Transfer Language
(RTL) 1. A kind of hardware description language (HDL) used
in describing the registers of a computer or digital
electronic system, and the way in which data is transferred
between them.
2. An intermediate code for a machine with an infinite number
of registers, used for machine-independent optimisation.
RTL was developed by Chris Fraser and
J. Davidson at the University of Arizona
in the early 1980s. RTL is used by the GNU C compiler,
gcc and by Davidson's VPCC (Very Portable C compiler).
["Quick Compilers Using Peephole Optimisation", Davidson et
al, Soft. Prac. & Exp. 19(1):79-97 (Jan 1989)].
(1994-11-16)