Tuesday 12 March 2013, 7.00pm for 7.30pm (Light refreshments available from 7.00pm)

Training Centre TC103, Elwes Building, University of Gloucestershire, The Park, Cheltenham, GL50 2QF

Free and open to all. No booking required.

Arthur Lawrence, Consultant, CEng FBCS.


Early computers were very slow and only had tiny amounts of memory available compared to today's machines. For example the PDP15 could have between 4 and 131 kilowords of memory and typically shipped with only 16 k-words of memory. To maximise memory and speed up processing, optimisation was common. With today's ultra-high speed processors and seemingly limitless amounts of memory (most machines have more than 1 Gb of memory and 1 Tb disks are fairly common) it is a little surprising that compilers still optimise code for increased execution speed and reduced memory usage. The use of optimisers in real time systems can introduce errors into code.

This talk will examine the optimisation process and will describe some erroneous code produced by optimisers that has been discovered during the course of a research project.