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Over his lifetime as a scientist, Dr. John Cocke made unique and creative contributions to information technology through his innovative developments in high performance system design.
His expertise in achieving high performance for a broad range of scientific applications led to remarkable advances in compiler design and machine architecture that culminated in his invention of the Reduced Instruction Set Computer (RISC) --- which profoundly affected the broad field of information technology. RISC is the basis for a Unix systems market that last year was $22.3 billion, according to industry analyst group, IDC.
"His tenure at IBM spanned an amazing time, 1956 to 1992," said Peter Capek, Cocke's colleague at IBM and close friend. "His career was unusual in its breadth. He was known for his work in computer architecture, but he was interested in everything -- circuits, storage, compilers -- any technology that could advance the state of the art."
Cocke was a founder and key innovator of the technology of compiler optimization, now used systematically throughout the computer industry to enable computers programmed in higher level languages such as FORTRAN, C, PASCAL and others to reach levels of efficiency comparable to -- and in some cases exceeding -- the levels of efficiency reachable by much more expensive and time-consuming programming techniques closer to the machine's instruction set.
Cocke's concept of the RISC resulted from his detailed study of the trade-offs between high performance machine organization and compiler optimization technology. He recognized that an appropriately defined set of machine instructions, program controls, and programs produced by a compiler -- carefully designed to exploit the instruction set -- could realize a very high performance processor with relatively few circuits. Critical to the success of RISC was the concept of an optimizing compiler able to use the reduced instruction set very efficiently and maximize performance of the machine. Cocke's RISC concept was contrary to the established direction of the functionally more complex instruction sets and machines. RISC was a fundamentally new concept in system design.
The first RISC Machine was developed as part of the 801 Minicomputer Project. Cocke contributed many detailed innovations in the 801 processor and associated optimizing PL.8 compiler, which was a redesign of the PL/1 compiler. The PL.8 compiler contained the first full implementation of Cocke's earlier "classical" optimization technologies as well as new technologies needed for RISC.
His contributions have been vital to several important areas of information technology. One is the fundamental cost of computing. RISC enables computers to run about twice as fast as other machines on the same number of circuits. The RISC concept was not in the mainstream; it was an idea at variance with the dominant ideas of its time. Without John Cocke's vision, it is not clear when it would have arrived.
Another critical area of Cocke's work is "logic simulation." Cocke invented a generalized special-purpose logic simulator, which runs many orders of magnitude faster than conventional simulations. In the 1980's a special purpose simulation machine known as the Yorktown Simulation Engine (built to Cocke's design) was used to simulate an entire computer at the logic gate level. The logic gate simulation produced answers faster than older computers executing programs in the machine's basic instruction set. Many of these simulation engines and their descendants are in use today. They enable the designer to verify and fix logical design before committing it to silicon. This substantially shortens VLSI (very large scale integration) development times, and such special simulation engines are widely used within the industry.
Among his many achievements, Cocke was named an IBM Fellow in 1972; he won the Turing award in 1987; the National Medal of Technology in 1991; and the National Medal of Science in 1994. Cocke received his bachelor’s degree in mechanical engineering and a Ph.D in mathematics from Duke University.
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