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His dismissal of the argument Knuth makes regarding the hot loops could have been explored a bit better. I found it weird he didn’t mention the difference of types of programs of then vs now. Even today, in scientific code it is still absolutely the case a lot of the time that a huge chunk of the runtime comes from a single very very hot loop. It might be hidden in a library, but it’s there. Instead he focuses only on “program size”. Knuth samples where very small FORTRAN programs (compared to today’s standards). Today’s program are bigger but the fundamental number crunching primitive of “let’s compute stuff in a loop” remains. It’s just buried under a pile of extra cruft (data loading, parallelism, dispatching etc).
Now we just deal with a lot more programs that are of a whole different class compared to what they where doing with computers in the 70s. We have much more I/O involved. And hot loops don’t like being I/O bound.
iirc, in the talk casey in fact does goes on about how he tried to find examples, but couldn't. in the q&a, he was also asked about this further.
(to be clear, I'm a big fan of Casey)
Titles aside, his talk is really insightful and it is super interesting to do a deep dive on these old computer/programming topics as the modern concepts were being discovered
Yeah Ive been meaning to watch that talk - I love listening to pretty much anything Casey says/does. He's extremely thoughtful and fair.
Exactly!
I would very much prefer something written down, so I could absorb this at my own pace. I know, gift horse, but still.
I used to do manual labor and I would work my way through like eight hours of audiobooks per day.
The basic idea is that the origin assumes a highly critical inner hot loop, don't assume where it is, and optimize there.
There's some other time spent saying this justifies slower abstractions for maintainability elsewhere.
I think the GOTOers just died out.
Some day null, statements (rather than expressions) and side-effects will have always been wrong.
Though lately I've been uploading the audio to AssemblyAI, I somehow still haven't used up my credits after several years lol
At one point I built a system that would summarize the transcript and I'd be able to ask questions about it, but Gemini can do that natively now so I usually just use that.
The best thing you could take away from this lecture is something a reasonable person should take away from the original "root of all evil" saying anyway. Measure. Measure. Measure. If you aren't measuring that's not optimization it's masturbation.
Ironically in the process of measuring for a third time yesterday I tripped a bug in Bill's language for which I opened an issue. This is not the goal of measuring three times but merely a happy accident.
Along the way Casey discovers (?) that Structured Programming means just what we today call programming†, that software was a lot smaller in the days when 4096 bytes of RAM was a good entry level option and that loads of these famous people from 1970s computer science knew each other.
† And knowing about this is one reason the Structured Concurrency people want that everywhere. Very possibly there's a future where it seems silly that people once wrote programs which did not use structured concurrency.
The problem is knowing what to measure. There's another saying
"When a measure becomes a target, it ceases to be a good measure."
As an example from memory, there was a game dev company that celebrated they had maxed out the cores on the PS3. That didn't mean anything though, anyone can max out the cores by filing them with bad code. But hey, their "measurement" told them they had maxed out the machine
This can be a problem, but much less so because so often we're doing "easy mode" where we don't need a proxy. The "it ceases to be a good measure" is because you're measuring a proxy. You wanted to deliver happiness, you measured wealth because it was easier to measure but seemed correlated and now you've got rich miserable people, oops. But software engineers can often measure the actual thing they want to improve directly, not a proxy and so it cannot cease to be a good measure.