Control structures in Illiac IV Fortran

ABSTRACT

As part of an effort to design and implement a Fortran compiler on the ILLIAC IV, an extended Fortran, called IVTRAN, has been developed. This language provides a means of expressing data and control structures suitable for exploiting ILLIAC IV parallelism. This paper reviews the hardware characteristics of the ILLIAC and singles out unconventiona features which could be expected to influence langluage (and compiler) design. The implications of these features for data layout and algorithm structure are discussed, and the conclusion is drawn that data allocation rather than code structuring is the crucial ILLIAC optimization problem. A satisfactory method of data allocation is then presented. Language structures to utilize this storage method and express parallel algorithms are described.

REFERENCES

• 1: Barnes, G.H., Brown, R.M, Kato, M., Kuck, D.J., Slotnick, D.L., and Stokes, R.Q. The ILLIAC IV computer. IEEL Trans. Comput. C-17 (Aug. 1968), 746--757.
• 2: Burroughs Corporation. ILLIAC IV system characteristics and programming manual. Defense, Space and Special Systems Group, Paoli, Pefinsylvania, June 30, 1970.
• 3: Kuck, D.J. ILLIAC IV software and application programming. IEEE Trans. Comput. C-17 (Aug. 1968), 758-770.
• 4: Robert E. Millstein , Edward P. Krugman , David Goldberg, Optimization for an array computer, ACM SIGPLAN Notices, v.5 n.9, September 1970 [doi>10.1145/987429.987431]

INDEX TERMS

Keywords:
ILLIAC IV Fortran, array allocation, array processing, explicit parallelism, parallel control structures, parallelism detection