UNCOL explained

UNCOL (Universal Computer Oriented Language) is a universal intermediate language for compilers. The idea was introduced in 1958, by a SHARE ad-hoc committee.^[1] It was never fully specified or implemented; in many ways it was more a concept than a language.

UNCOL was intended to make compilers economically available for each new instruction set architecture and programming language, thereby reducing an N×M problem to N+M.^[2] Each machine architecture would require just one compiler back end, and each programming language would require one compiler front end. This was a very ambitious goal because compiler technology was in its infancy, and little was standardized in computer hardware and software.

History

The concept of such a universal intermediate language is old: the SHARE report (1958) already says "[it has] been discussed by many independent persons as long ago as 1954." Macrakis (1993) summarizes its fate:

UNCOL is sometimes used as a generic term for the idea of a universal intermediate language. The Architecture Neutral Distribution Format is an example of an UNCOL in this sense, as are various bytecode systems such as UCSD Pascal's p-code, and most notably Java bytecode.^[3]

See also

• LLVM
• GIMPLE

Notes

1. Strong . J. . Wegstein . J. . Tritter . A. . Olsztyn . J. . Mock . O. . Steel . T. . The Problem of Programming Communication with Changing Machines: A Proposed Solution . Communications of the ACM . August 1958 . 1 . 8 . 12–18 . 10.1145/368892.368915 . 21 February 2022. free .
2. UNCOL and Reversing modifications from mailing lists . 23 November 2021 . 24 November 2021 . dmarc-ietf . John Levine.
3. John English, Introduction to Operating Systems: Behind the Desktop, Palgrave MacMillan 2005,, p. 10

References

• Conway. Melvin E.. Proposal for an UNCOL. Communications of the ACM. 1 October 1958. 1. 10. 5–8. 10.1145/368924.368928 . 0001-0782. free.
• Jean E. Sammet, Programming Languages: History and Fundamentals, Prentice-Hall, 1969. Chapter X.2: UNCOL (Significant Unimplemented Concepts), p. 708.
• SHARE Ad-Hoc Committee on Universal Languages (J. Strong, J. Olsztyn, J. Wegstein, O. Mock, A. Tritter, T. Steel), "The Problem of Programming Communication with Changing Machines", Communications of the ACM 1:8:12–18 (August 1958) and 1:9:9–15 (September 1958).
• Stavros Macrakis, "From UNCOL to ANDF: Progress in Standard Intermediate Languages", White Paper, Open Software Foundation Research Institute, RI-ANDF-TP2-1, January, 1992. Available at CiteSeer
• T.B. Steel, Jr., "UNCOL: Universal Computer Oriented Language Revisited", Datamation (Jan/Feb 1960), p. 18.
• T.B. Steel, Jr., "A First Version of UNCOL", Proc. Western Joint Computer Conference 19:371 (Los Angeles, May 9–11, 1961).
• T.B. Steel, Jr., "UNCOL: The Myth and the Fact", Annual Review in Automatic Programming 2:325 (1961).