Debugging compile time memory usage

[Nicholas Wilson]

On Sunday, 24 June 2018 at 14:16:26 UTC, Kamil Koczurek wrote:
> I recently wrote a brainfuck compiler in D, which loads the BF 
> source at compile time, performs some (simple) optimizations, 
> translates everything to D and puts it into the source code 
> with a mixin.
>
> I did manage to get some pretty good performance, but for some 
> programs in brainfuck I have to use LDC instead of DMD because 
> the latter runs out of memory. Is there a way for me to 
> optimize my code in such a way that DMD will be able to compile 
> it?
>
> D code: https://pastebin.com/fg1bqwnd
> BF program that works: 
> https://github.com/erikdubbelboer/brainfuck-jit/blob/master/mandelbrot.bf
> BF program that makes DMD crash: 
> https://github.com/fabianishere/brainfuck/blob/master/examples/hanoi.bf
>
> After putting BF code in code.bf and D in main.d, I compile it 
> with the following command: dmd main.d -J./
>
> Error msg: unable to fork: Cannot allocate memory
> DMD version: DMD64 D Compiler v2.080.0-dirty

If you were able to compile it with LDC and not DMD, then that is 
most likely due to the LDC executable being 64-bit (limited to 
available system RAM+swaps) and the DMD executable being 32-bit 
(limited to 4GB).

If you want to use DMD, build a 64-bit version yourself and 
complain on general that the releases are not 64-bit.