an Interview with
frances e. allen
fran allen on cs: “it’s just such an amazing field, and it’s changed the world, and we’re just at the beginning…”
PHO TOGRAPH BY FRANK BECERRA, JR. / THE JOURNAL NEWS
ACm feLLow fRaNCeS e. aLLeN, recipient of the 2006 ACM A.M. Turing Award and IBM Fellow Emerita, has made fundamental contributions to the theory and practice
of program optimization and compiler construction over a 50-year career.
Her contributions also greatly extended earlier work in automatic program
parallelization, which enables programs to use multiple processors simultaneously in order to obtain faster results. These techniques made it
possible to achieve high performance
from computers while programming
them in languages suitable to applications. She joined IBM in 1957 and
worked on a long series of innovative
projects that included the IBM 7030
(Stretch) and its code-breaking co-processor Harvest, the IBM Advanced
Computing System, and the PTRAN
(Parallel Translation) project. She is
an IEEE Fellow, a Fellow of the Computer History Museum, a member of
the American Academy of Arts and
Sciences, and a member of the U.S.
National Academy of Engineering.
ACM Fellow Guy L. Steele Jr. visited
Allen at her office in the IBM T.J. Watson Research Center in 2008 for an
extended oral interview. The complete
transcript of this interview is available
in the ACM Digital Library; presented
here is a condensed version that highlights Allen’s technical accomplishments and provides some anecdotes
about her colleagues.
Your first compiler work was for IBm
Yes. In 1955, IBM recognized that to
be 100 times faster than any machine
existing or planned at the time, the major performance problem to overcome
was latency to memory. The advanced
a See the December 2010 Communications Historical Perspectives column “IBM’s Single-Processor Supercomputer Efforts” for more
discussion of the IBM Stretch supercomputer.
ideas and technologies they put into
Stretch were to address that problem.
Six instructions could be in flight at the
same time. The internal memory was
interleaved, and data would arrive out
of order—data and instructions were
both stored in this memory. They built
a very complex buffering system and
look-ahead. John Cocke, when he came
in 1956, was put in charge of the look-ahead for instructions. It was also architected to have precise interrupts. So