I agree with the overall point of the article, but I feel compelled to be _that guy_ and point out that most of IBM's systems programming involved various dialects of PL/I, not Fortran, and they went through a bunch of different iterations on those compilers and their code generators.

How did we get so much better at writing compilers? Was it a better understanding of how to make syntax trees with ADTs etc?

Fortran H was faster than the fastest punchcard feeder of the time. That bottleneck is unfortunately long gone, without the same magnitude of improvement on the other side. (Physical limits, amazing optimisations, etc.)

Last time I was working with CCE, I was looking at blistering runtime speeds, but six or seven hour compiles. Huge codebase (40mil+ LoC), and the optimisations were great, but not exactly a fantastic dev lifestyle.

Beautifully written but when the lack of a better compiler gets attributed to rational actions my brain glitched. That’s not fitting my mental model of how big corps operate at all!

Occam’s razor IBM didn’t invest in Fortran I because the internal political environment at the corporation didn’t have the incentives aligned to do so. This is completely orthogonal to whether they could have used a better compiler or not.

The definition of "passable compiler" in 1992 must have been very different from what it is today; while third year students write interpreters and compilers, nobody would call them useful or passable.

> Now a question: Since we're obviously thousands of times better at producing compilers than we were fifteen years ago, so much so that a single undergraduate can write a passable one in four months, why hasn't IBM invested millions of dollars and hundreds of programmer-years to produce a super FORTRAN I compiler that's thousands of times better than the FORTRAN H compiler?

s/FORTRAN I/Mythos/ for the 2026 version of this.

Dupe: https://news.ycombinator.com/item?id=48622814

Beautifully written. Was this a note to self. If so amazing.

what do you think of it?