Josh Fisher


Joseph A "Josh" Fisher is an American and Spanish computer scientist noted for his work on VLIW architectures, compiling, and instruction-level parallelism, and for the founding of Multiflow Computer. He is a Hewlett-Packard Senior Fellow.

Biography

Fisher holds a BA in mathematics from New York University and obtained a Master's and PhD degree in Computer Science from The Courant Institute of Mathematics of New York University.
Fisher joined the Yale University Department of Computer Science in 1979 as an assistant professor, and was promoted to associate professor in 1983. In 1984 Fisher left Yale to found Multiflow Computer with Yale colleagues John O'Donnell and John Ruttenberg. Fisher joined HP Labs upon the closing of Multiflow in 1990. He directed HP Labs in Cambridge, MA USA from its founding in 1994, and became an HP Fellow and then Senior Fellow upon the inception of those titles at Hewlett-Packard. Fisher retired from HP Labs in 2006.
Fisher is married to Elizabeth Fisher; they have a son, David Fisher, and a daughter, Dora Fisher. He holds Spanish citizenship due to his Sephardic heritage.

Work

Trace Scheduling

In his Ph.D. dissertation, Fisher created the Trace Scheduling compiler algorithm and coined the term Instruction-level parallelism to characterize VLIW, superscalar, dataflow and other architecture styles that involve fine-grained parallelism among simple machine-level instructions. Trace scheduling was the first practical algorithm to find large amounts of parallelism between instructions that occupied different basic blocks. This greatly increased the potential speed-up for instruction-level parallel architectures.

The VLIW architecture style

Because of the difficulty of applying trace scheduling to idiosyncratic systems that in theory should have been suitable targets for a trace scheduling compiler, Fisher put forward the VLIW architectural style. VLIWs are normal computers, designed to run compiled code and used like ordinary computers, but offering large amounts of instruction-level parallelism scheduled by a trace scheduling or similar compiler. VLIWs are now used extensively, especially in embedded systems. The most popular VLIW cores have sold in quantities of several billion processors.

Multiflow Computer

Multiflow was founded to commercialize trace scheduling and VLIW architectures, then widely thought to be impractical. Multiflow's technical success and the dissemination of its technology and people had a great effect on the future of computer science and the computer industry.

Awards and honors