Viewing profile — gsg

This works until the analogue of monotremes shows up to ruin your supposedly flawless categorisation.

System F doesn't have general recursion. Extensions with a letrec-like construct are common, and are sometimes inaccurately called 'System F', but those languages do not have the p…

There are some examples, for example Crowbar is an OCaml tool that uses AFL to drive property based tests.

chrisseaton is talking about the bump-pointer allocator in a modern GC, not an implementation of malloc/free. The performance characteristics are quite different. In a generational…

Yes, this has been done a few times. CDR-coding was a hardware-assisted method of unrolling a Lisp list (complicated somewhat by the need to support mutation of car and cdr) that a…

You can easily see by searching for 'kmalloc' (or 'malloc') at https://github.com/torvalds/linux/blob/master/include/linux/... that it does no such thing. Here's the logic for addi…

BOUND is pretty slow, and requires an odd start/end pair to be placed in memory. I don't see any reason that it would be better than the usual unsigned comparison + branch that lan…

Sure, but that didn't change much between x86 and x86-64. Perhaps it got a little worse because the SIMD instructions aren't overflow check friendly.

That still exists though? add rax, rbx/jo overflow_error is how you do overflow checking on x86-64.

> As far as I understand it, this limitation is also the only thing preventing tail-call elimination in C/C++. That is not the case. Guaranteed TCE requires deallocating the stack …

Interesting if somewhat opaque. I'm familiar with defunctionalisation as an alternative to closure conversion in whole program compilers and as a description of how data types are …

Lambda lifting is an alternative to closure conversion, so it doesn't get rid of closures so much as obviate introducing them at all. The two transformations are fairly closely rel…

My guess would be that they were thinking h <= SIZE_MAX / w, and added the most obvious logic to avoid a division by zero.

Monomorphising doesn't work for rank-n polymorphism, either. (This is mentioned on the page.)

A bunch of languages have something much like .let/.apply already, since it's pretty much just function application in reverse order: "foo" |> String.length |-> printf "%d\n" |> fu…

This is nonsense. Modern compilers don't work by generating the results you see with -O0 and then optimising; the poor quality of -O0 code is the result of skipping register alloca…

First, deriving is just pointer arithmetic and doesn't copy anything. Second, standard flat closure representations already involve copying parts of environments, with any sharing …

Mutually recursive functions can be closure converted without cycles by deriving closure values from each other rather than storing them in each other.

I see. It seems like that would still make calling supporting routines annoyingly expensive, but perhaps that (and the extra tag memory) doesn't matter as much as I think it does. …

How do you pass arguments? In two registers? On the stack?

There's a decent textbook written in the incremental style argued for by the author: Essentials of Compilation. It features compilers for seven languages, written in Racket, each w…

My complaint with |> is that it makes code with nesting look quite different based on argument position. Argument position is not a very interesting property, so it doesn't seem ri…

> some random OO language on Amiga that I've never really been able to track down Maybe Amiga E? http://strlen.com/amiga-e/

So... the only way to stop a bad guy with a GAN is a good guy with a GAN?