Add precached LTO variants of libraries

[RReverser]

Add precached LTO variants of libraries

[trzecieu]

I think so! Good idea!

[trzecieu]

Hi, I see that there is an attempt in your case to create a new cache entry under wasm-lto but I have a difficult to reproduce it. Simple command doesn't work.

em++ test.cpp -flto -o test.js -s WASM=1

Is it possible for you to share compilation flags?

[trzecieu]

I've addressed blindly this issue in the commit ec1eaff, I will update images soon with that change.

[RReverser]

em++ test.cpp -flto -o test.js -s WASM=1

Hmm, I'll need some time to get around but could you try adding optimisation and/or debug flags?

[trzecieu]

I've tested a various of flags under 1.39.5 - nothing has worked unfortunately.
Some images have been already updated with precompiled LTO, i.e:

• docker pull trzeci/emscripten-fastcomp:1.39.7
• docker pull trzeci/emscripten-upstream:1.39.7
  Also would be useful if you tell which version of emscripten do you use, as I've found that this emscripten-core/emscripten#10603 might be related

[RReverser]

Ah, it probably depends on contents of your test.cpp and which libraries end up being linked. If it's not using the standard library, it might be skipping these compilations altogether.

as I've found that this emscripten-core/emscripten#10603 might be related

Unlikely - that issue is just about size inefficiency, which is not very related.

[trzecieu]

So I've added a bunch of most common libs to cache with lto, please check if something missing I can add explicitly to the list : )

Thanks!