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Autocode is the name of a family of "simplified coding systems", later called programming languages, devised in the 1950s and 1960s for a series of digital computers at the Universities of Manchester, Cambridge and London. Autocode was a generic term; the autocodes for different machines were not necessarily closely related as are, for example, the different versions of the single language FORTRAN. In the 1960s, high-level programming languages using a compiler were commonly called autocodes.〔〕 Examples of autocodes are COBOL and Fortran.〔〕 == Glennie's Autocode == The first autocode and its compiler were developed by Alick Glennie in 1952 for the Mark 1 computer at the University of Manchester and is considered by some to be the first compiled programming language. His main goal was to make the programming of Mark 1 machine, known for its particularly abstruse machine code, comprehensible. Although the resulting language was much clearer than the machine code, it was still very machine dependent. 〔Knuth, p. 42-43〕 Below is an example of Glennie's Autocode function which calculates the formula: . The example omits necessary scaling instruction needed to place integers into variables and assumes that results of multiplication fit into lower accumulator. c@VA t@IC x@½C y@RC z@NC INTEGERS +5 →c # Put 5 into c →t # Load argument from lower accumulator to variable t +t TESTA Z # Put |t| into lower accumulator -t ENTRY Z SUBROUTINE 6 →z # Run square root subroutine on lower accumulator # value and put the result into z +tt →y →x # Calculate t^3 and put it into x +tx →y →x +z+cx CLOSE WRITE 1 # Put z + (c * x) into lower accumulator and return User's manual of Glennie's Autocode Compiler mentioned that "the loss of efficiency is no more than 10%". 〔Knuth, p. 48〕 Autocode's impact on other Manchester users' programming habits was negligible. It wasn't even mentioned in Brooker's 1958 paper called "The Autocode Programs developed for the Manchester University Computers". 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Autocode」の詳細全文を読む スポンサード リンク
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