About B. Ramakrishna Rau
1951–2002

B. Ramakrishna RauB. Ramakrishna (Bob) Rau was widely recognized as an expert in the field of VLIW (Very Long Instruction Word) computing, which is the basis of many of today’s computer microarchitectures.

Dr. Rau was a senior research scientist at HP Labs, where he held the title of Hewlett-Packard Laboratories Scientist. He was also the manager of HP Labs’ Compiler and Architecture Research (CAR) group.

On joining HP in 1989, Dr. Rau started HP Lab’s research program in VLIW and instruction-level parallel (ILP) processing. This resulted in the development of the Explicitly Parallel Instruction Computing (EPIC) style of architecture that is the basis for the IA-64. Dr. Rau’s research interests focused on evolving and adapting the EPIC architecture and compiler technologies, and the systolic array technology, to enable the automatic architecting of custom, application-specific, embedded processors.

Dr. Rau was a co-founder of Cydrome Inc. which developed and productized one of the first VLIW mini-supercomputers, the Cydra 5.

He taught at the University of Illinois, Urbana-Champaign, where he was an Adjunct Professor. He held twelve patents, published numerous research papers in the area of VLIW computing, and co-edited a book on instruction-level parallelism. He received his B.Tech degree from the Indian Institute of Technology, Madras, India, and his MS and Ph.D. degrees from Stanford University.

Dr. Rau’s primary contributions to Trimaran were to create the environment which enabled the research leading to the development of EPIC, HPL-PD and Elcor, and to forge the research relationships with the University of Illinois and New York University which resulted in Trimaran. He made contributions to Elcor/Trimaran on topics such as region-based compiling, dynamic single assignment (DSA) and expanded virtual registers (EVRs), modulo scheduling, rotating register allocation, and machine description databases for machine description-driven compilation.

Dr. Rau also worked on HP’s PICO (Program In, Chip Out) project, whose goal was to develop the capability to take an embedded application and to automatically design highly customized computing hardware that is specific to that application, as well as any compiler that might be needed.

He was a recipient of the ACM/IEEE Eckert-Mauchly Award. He was a Fellow of both the ACM and the IEEE. Dr. Rau passed away in 2002 after losing a long battle with cancer.