skip to content

Department of Computer Science and Technology

World Cup 2018 Sticker Collecting

10 May 2018

Once again a major football tournament is approaching and my son is collecting stickers of all the teams who have reached the finals. This time it’s the World Cup in Russia and the album published by Panini has 682 to collect. I’ve blogged before about the maths behind collecting stickers so you can calculate how many packets of five distinct stickers you expect to need to finish it. At the time, to help me visualise this, I wrote a web page with a bit of JavaScript on it to do the calculations. This time I’ve looked over it again and increased its functionality a little, so I’ve decided it’s robust enough to advertise. It’s on my main university site...

Read more

Alias Analysis in HELIX

21 December 2015

One of the most important parts of our HELIX compiler is the data dependence analysis we run on the compiler’s IR to determine which instructions are independent of each other. You can read more about HELIX in general in our original CGO 2012 paper (click through my publications page to get free access to the ACM version).

HELIX’s initial data dependence pass is split into two phases, and it’s the memory alias analysis stage that is most interesting. This has the job of identifying the locations in memory that are read and written by each instruction so that we can respect all data dependences within the loops we parallelise. Since alias analysis is not precise, we need to...

Read more