Author: regehr

  • 200 Compiler Bugs

    This morning I reported the 200th bug found by our compiler testing tool.  It is a new way to crash GCC.  The failure-inducing input is not pretty so I won’t give it here, but it can be found in GCC’s bugzilla.  Although the testing tool is now entirely developed by some excellent PhD students, I […]

  • How to Evaluate a Computer Systems Research Paper

    Some excellent resources exist about how to write a good systems paper. This post is about a slightly different topic. In a typical recent year I review about 100 papers, mostly conference papers 8-14 pages long in 9 or 10 point font. People in similar positions — mid-career computer systems professors — are generally in […]

  • 50 Vertical Miles

    A little over a year ago my family moved to a house near the north edge of Salt Lake City.  Although access to real mountains is not great — it’s about a three-hour walk to the nearest 8000′ peak and a major slog to a 9000′ peak — the foothill access is excellent.  At the […]

  • Nine ways to break your systems code using volatile

    The volatile qualifier in C/C++ is a little bit like the C preprocessor: an ugly, blunt tool that is easy to misuse but that — in a very narrow set of circumstances — gets the job done.  This article will first briefly explain volatile and its history and then, through a series of examples about […]

  • Is That a Compiler Bug?

    It’s common for a computer program to display behavior seemingly unrelated to its source code.  Additionally, programs written in C/C++ frequently change their behavior when the compiler optimization options are changed.  This post is a quick guide to figuring out if the compiler is at fault.  This post was motivated by a blog post by […]

  • TRIGA

    Today I visited Utah’s TRIGA: a nuclear reactor located in the building where I’ve had an office for about nine years.  I’ve had a low-grade fascination with these devices since reading about them many years ago in one of Freeman Dyson’s books.  Unlike powerplant reactors, which rely on elaborate safety systems, the TRIGA series is […]