4 ms·

Apparently this sort of thing was relatively common. In the late 60's my aunt worked for MetLife as a programmer and would routinely hide data in execution code

by J3L2404 15y ago

Apparently this sort of thing was relatively common. In the late 60's my aunt worked for MetLife as a programmer and would routinely hide data in execution code to save space. When she became pregnant they put her on 'leave' but refused to reinstate her after my cousin was born. Unfortunately for them only she knew about the hidden data and they were forced to hire her back as a consultant, for much more money, when things inevitably broke.

gigamonkey 15y ago
Another similar story, from my interview with Guy Steele in Coders at Work: This may seem like a terrible waste of my effort, but one of the most satisfying moments in my career was when I realized that I had found a way to shave one word off an 11-word program that Gosper had written. It was at the expense of a very small amount of execution time, measured in fractions of a machine cycle, but I actually found a way to shorten his code by 1 word and it had only taken me 20 years to do it. Seibel: So 20 years later you said, “Hey Bill, guess what?” Steele: It wasn’t that I spent 20 years doing it, but suddenly after 20 years I came back and looked at it again and suddenly had an insight I hadn’t had before: I realized that by changing one of the op codes, it would also be a floating point constant close enough to what I wanted, so I could use the instruction both as an instruction and as a floating point constant. Seibel: That’s straight out of “The Story of Mel, a Real Programmer.” Steele: Yeah, exactly. It was one of those things. And, no, I wouldn’t want to do it in real life, but it was the only time I’d managed to reduce some of Gosper’s code. It felt like a real victory. And it was a beautiful piece of code. It was a recursive subroutine for computing sines and cosines. So that’s the kind of thing we worried about back then.
- ArbitraryLimits 15y ago
  Not really related, but Gosper's algorithm (http://en.wikipedia.org/wiki/Gospers_algorithm http://en.wikipedia.org/wiki/Gospers_algorithm) is the thing I've learned in the last few years that blew my mind the hardest. It's how Maple or Mathematica can reduce your crazy sums to a single formula. Earlier work was apparently pioneered by a nun: http://en.wikipedia.org/wiki/Mary_Celine_Fasenmyer http://en.wikipedia.org/wiki/Mary_Celine_Fasenmyer

by J3L2404 15y ago

gigamonkey 15y ago

Another similar story, from my interview with Guy Steele in Coders at Work: This may seem like a terrible waste of my effort, but one of the most satisfying moments in my career was when I realized that I had found a way to shave one word off an 11-word program that Gosper had written. It was at the expense of a very small amount of execution time, measured in fractions of a machine cycle, but I actually found a way to shorten his code by 1 word and it had only taken me 20 years to do it. Seibel: So 20 years later you said, “Hey Bill, guess what?” Steele: It wasn’t that I spent 20 years doing it, but suddenly after 20 years I came back and looked at it again and suddenly had an insight I hadn’t had before: I realized that by changing one of the op codes, it would also be a floating point constant close enough to what I wanted, so I could use the instruction both as an instruction and as a floating point constant. Seibel: That’s straight out of “The Story of Mel, a Real Programmer.” Steele: Yeah, exactly. It was one of those things. And, no, I wouldn’t want to do it in real life, but it was the only time I’d managed to reduce some of Gosper’s code. It felt like a real victory. And it was a beautiful piece of code. It was a recursive subroutine for computing sines and cosines. So that’s the kind of thing we worried about back then.

ArbitraryLimits 15y ago
Not really related, but Gosper's algorithm (http://en.wikipedia.org/wiki/Gospers_algorithm http://en.wikipedia.org/wiki/Gospers_algorithm) is the thing I've learned in the last few years that blew my mind the hardest. It's how Maple or Mathematica can reduce your crazy sums to a single formula. Earlier work was apparently pioneered by a nun: http://en.wikipedia.org/wiki/Mary_Celine_Fasenmyer http://en.wikipedia.org/wiki/Mary_Celine_Fasenmyer