Category: Random

  • Introduction to Precision Farming

    [My father, David Regehr, encouraged me to write this piece, provided some of its content, edited it, and agreed to let me use data from his farm.] [For readers outside the USA: Alas, we do not farm in metric here. In case you’re not familiar with the notation, 10″ is ten inches (25.4 cm) and […]

  • A Few Pictures

    Paris was very quiet on Saturday and people on the street looked tired, having (like us) stayed up most of the night watching the news, listening to sirens, and worrying about things. Today was sunny and warm and things seemed more normal; plenty of folks out jogging, sitting in parks, other usual weekend activities.

  • Classic Bug Reports

    A bug report is sometimes entertaining either because of the personalities involved or because of the bug itself. Here are a collection of links into public bug trackers; I learned about most of these in a recent Twitter thread. GCC’s magnum opus, its War and Peace, is Bug 323: optimized code gives strange floating point […]

  • Booster Test

    Ever since learning that the space shuttle booster motors were manufactured and tested at ATK in Promontory Utah — not too far from where I live — I wanted to see one of the tests. I didn’t manage to do that before the shuttle program was shut down, but today I got to see something […]

  • Inversions in Computing

    Some computer things change very slowly; for example, my newish desktop at home has a PS/2 port. Other things change rapidly: my 2010 iPad is kind of a stone-age relic now. This kind of differential progress creates some funny inversions. A couple of historical examples: Apparently at one point in the 80s or 90s (this […]

  • What I Accomplished in Grad School

    I often talk to students who are thinking about grad school. The advice I generally give is a dressed-up version of “Just do whatever the hell will make you happy.” But if we all had solid ideas about what would make us happy then, well, we’d probably be a lot more happy. Here’s a list […]

  • Automatically Entering the Grand C++ Error Explosion Competition

    G++ can be comically verbose; developers sometimes like to wallpaper their cubes with choice error messages from Boost or STL programs. The Grand C++ Error Explosion Competition asks the question: how large can we make the ratio between error output and compiler input? I’m not much of a C++ person but when the contest was […]

  • Sometimes Compilers are Cute

    regehr@john-home ~ $ clang -Os -S -o – foo.c foo1: movb %sil, %cl roll %cl, %edi movl %edi, %eax ret foo2: movb %sil, %cl rorl %cl, %edi movl %edi, %eax ret foo3: bswapl %edi movl %edi, %eax ret foo4: bswapl %edi movl %edi, %eax ret regehr@john-home ~ $ gcc -Os -S -o – foo.c foo1: […]

  • According to Googer

    This post is all Eddie’s fault. Things that are exquisitely fortuitous her sudden and unexpected departure with a drunken Hanes waving a gun timing positioning several kinds of parameters of the universe that they chose sh** to describe this newest of Beetoven’s competitors that Phaidon, the British publisher, is issuing new editions of Ungerer classics, […]

  • Funniest Computer Book?

    The other day Eric Eide noticed The UNIX Hater’s Handbook on my desk and remarked that there aren’t enough funny computer books. This is undeniably true. So now I’m trying to find the funniest computer book and I’d appreciate some help. Here are a few guidelines: Not really looking for a Dilbert collection. Let’s just […]