4 ms·

I regularly read the assembly output of the OCaml compiler I'm using and there are very few surprises. The mapping from source to generated assembly is quite st

I regularly read the assembly output of the OCaml compiler I'm using and there are very few surprises. The mapping from source to generated assembly is quite straightforward. You couldn't say the same for Haskell, though. So it depends on which FP language you're using.

carterschonwald 7y ago
Actually I’ve found it pretty easy to track / reason about. But I guess I do have a decent mental model for how the compiler works
chowells 7y ago
I absolutely can say that about Haskell. You have to actually learn the language, but it doesn't do anything unpredictable.
- deleted 7y ago
  [deleted]
skohan 7y ago
Does OCaml give you enough tools to optimize around things like CPU-cache and memory management costs? It's one thing to know what kind of assembly is going to be produced by a block of code, but it's another thing to be able to get the machine to do exactly what you want.
- classified 7y ago
  If “to get the machine to do exactly what you want” is an important goal, I'd recommend C or C++. Those are well known tools for those purposes. FP languages are rather about getting more ideas from math into how you structure your code.
  - OskarS 7y ago
    I don’t think you need to go that low level. I find it much easier to optimize around things like memory layout, allocation patterns and cache effects even in Java and C# compared to (essentially) any functional language. I think this is just a feature of imperative languages over functional ones. Functional languages are excellent for many things, but not for this stuff.
    - Bjartr 7y ago
      Where should I look to learn about doing those things in Java? Last time I tried looking for guidance I mostly found people saying it's not worth the effort since the JVM JIT will do better.
      - lonelappde 7y ago
        This thread is for people who are smarter than compilers. Java is not different from C in that regard.
  - ummonk 7y ago
    Rust on the other hand is zero-cost abstraction but pushes you to write functional code.
- pjmlp 7y ago
  You can analyze Assembly code just like in any other AOT compiled language. Have a go at in Godbolt, https://godbolt.org/ https://godbolt.org/ OCaml also integrates with perf on Linux, https://ocaml.org/learn/tutorials/performance_and_profiling.html https://ocaml.org/learn/tutorials/performance_and_profiling.... Some performance tips from an old partially archived page. https://hackerfall.com/story/writing-performance-sensitive-ocaml-code-1 https://hackerfall.com/story/writing-performance-sensitive-o... And if you are feeling fancy, doing some pointer style programming https://ocaml.org/learn/tutorials/pointers.html https://ocaml.org/learn/tutorials/pointers.html
lonelappde 7y ago
Wrong metric. It's not the mapping that matters, it's the assembly that matters.

carterschonwald 7y ago

Actually I’ve found it pretty easy to track / reason about. But I guess I do have a decent mental model for how the compiler works

chowells 7y ago

I absolutely can say that about Haskell. You have to actually learn the language, but it doesn't do anything unpredictable.

deleted 7y ago
[deleted]

skohan 7y ago

Does OCaml give you enough tools to optimize around things like CPU-cache and memory management costs? It's one thing to know what kind of assembly is going to be produced by a block of code, but it's another thing to be able to get the machine to do exactly what you want.

classified 7y ago
If “to get the machine to do exactly what you want” is an important goal, I'd recommend C or C++. Those are well known tools for those purposes. FP languages are rather about getting more ideas from math into how you structure your code.
- OskarS 7y ago
  I don’t think you need to go that low level. I find it much easier to optimize around things like memory layout, allocation patterns and cache effects even in Java and C# compared to (essentially) any functional language. I think this is just a feature of imperative languages over functional ones. Functional languages are excellent for many things, but not for this stuff.
  - Bjartr 7y ago
    Where should I look to learn about doing those things in Java? Last time I tried looking for guidance I mostly found people saying it's not worth the effort since the JVM JIT will do better.
    - lonelappde 7y ago
      This thread is for people who are smarter than compilers. Java is not different from C in that regard.
- ummonk 7y ago
  Rust on the other hand is zero-cost abstraction but pushes you to write functional code.
pjmlp 7y ago
You can analyze Assembly code just like in any other AOT compiled language. Have a go at in Godbolt, https://godbolt.org/ https://godbolt.org/ OCaml also integrates with perf on Linux, https://ocaml.org/learn/tutorials/performance_and_profiling.html https://ocaml.org/learn/tutorials/performance_and_profiling.... Some performance tips from an old partially archived page. https://hackerfall.com/story/writing-performance-sensitive-ocaml-code-1 https://hackerfall.com/story/writing-performance-sensitive-o... And if you are feeling fancy, doing some pointer style programming https://ocaml.org/learn/tutorials/pointers.html https://ocaml.org/learn/tutorials/pointers.html

lonelappde 7y ago

Wrong metric. It's not the mapping that matters, it's the assembly that matters.