Compiling code containing very long arrays takes, a strangely long amount of time.

[mstewartgallus]

In order to compile resources into my application statically, I automatically generate very long arrays. These take an extremely long amount of time to compile.

[Thiez]

Do you have some example code that shows this problem in action? How long is 'very long'?

[mstewartgallus]

@Thiez Sure, I'd be happy to give you an example of the code. I just didn't attach it because it is very long, and boring, and an alternative is easily auto-generated. Here's a link to a gist https://gist.github.com/sstewartgallus/5587348

[Thiez]

It seems the compiler is making LLVM generate an enormous number of moves, which LLVM then tries to optimize (without much success). I think this is related to #3025.

As a workaround you might try to put the contents of the SpriteList in a top-level static, then generate the 'real' SpriteList from the static structure with many calls to to_owned (core::vec). Hopefully this will generate better code.

[mstewartgallus]

@Thiez Unfortunately, I can not create a top level static structure that has arrays due to issue #5917

[msullivan]

How long was it taking? Not sure the best way to deal with this. I seem to recall C compilers sometimes being unhappy with huge arrays as well...

[thestinger]

As far as I know, these issues have been fixed and we generate loops whenever possible. There would need to be a reproducible test case comparing rustc and clang unfavourably for it to be considered an issue.