What follows is a summary of the main contributions of a paper by Nadesh Ramanathan, George Constantinides, and myself that will be presented at the FCCM 2018 conference. If you want to compute something, you have two broad options: do it in software, or do it in hardware. A custom piece of hardware can give you… Continue reading Concurrency-aware scheduling for high-level synthesis
What follows is a summary of the main contributions of a paper I wrote with Nathan Chong and Tyler Sorensen for the PLDI 2018 conference. This project studies two features of a modern computer, one called out-of-order execution and one called transactional memory. Out-of-order execution is where a computer chooses, for performance reasons, to perform its instructions in an order… Continue reading What do you get if you cross Weak Memory with Transactional Memory?
DBLP is an online database of academic publications in computer science and related fields. Handily, it provides a Java API for accessing the data programmatically. In this blog post, I share a few fun facts I discovered while using this API to explore the data that DBLP holds about two of the main conferences on… Continue reading Who has the most POPL and PLDI papers?
DBLP is an online database of academic publications in computer science and related fields. Handily, it provides a Java API for accessing the data programmatically. In this blog post, I share a few fun facts I discovered while using this API to explore the data that DBLP holds about four conferences on FPGA technology; namely,… Continue reading So, who has the most FPGA, FCCM, FPL, and FPT papers?
In their POPL'17 paper, Shaked Flur, Susmit Sarkar, Christopher Pulte, Kyndylan Nienhuis, Luc Maranget, Kathy Gray, Ali Sezgin, Mark Batty, and Peter Sewell describe a semantics of weakly-consistent memory that copes (for the first time) with mixed-size memory accesses. In this blog post, I describe how their semantics can be explained rather nicely with some graphical… Continue reading Ribbon Diagrams for Weak Memory
What follows is a summary of the main contributions of a paper I wrote with Nadesh Ramanathan, Shane Fleming, and George Constantinides for the FPGA 2017 conference. Languages like C and C++ allow programmers to write concurrent programs. These are programs whose instructions are partitioned into multiple threads, all of which can be run at the same time.… Continue reading Translating lock-free, relaxed concurrency from software into hardware
My POPL 2017 paper with Mark Batty, Tyler Sorensen, and George Constantinides is all about memory consistency models, and how we can use an automatic constraint solver to compare them. In this blog post, I will discuss: What are memory consistency models, and why do we want to compare them? Why is comparing memory consistency… Continue reading Memory Consistency Models, and how to compare them automatically
It is quite well-known that the memory operations and fences provided by the C/C++11 languages are pretty complicated and confusing. For instance, my OOPSLA 2015 paper (joint with Batty, Beckmann, and Donaldson) explains that a proposed implementation of these instructions for next-generation AMD graphics cards is faulty because the designers misunderstood how they worked. And… Continue reading cppreference.com gets acquire/release instructions wrong
I believe that normalised data should be plotted on a logarithmic scale. (By "normalised data", I refer to data that is the ratio between two measurements that have the same dimension. Examples of such data include the ratio between the execution time of a program before a proposed compiler optimisation has been applied and the execution time of that program… Continue reading Why we should plot normalised data on a logarithmic scale
It's pretty common for database-driven apps to display a "last updated" field. For instance, here is a screenshot of my Mail app on my iPhone, showing that my emails were "Updated Just Now". And here is a screenshot from the RealTimeTrains app, showing that the information was "Updated a few seconds ago". Why do apps… Continue reading Bad UX design: “Updated Just Now”