Enable Link-Time Optimization (LTO) for loco-cli

[zamazan4ik]

Hi!

I noticed that in the Cargo.toml file Link-Time Optimization (LTO) for loco-cli is not enabled. I suggest switching it on since it will reduce the binary size (always a good thing to have) and will likely improve the application's performance.

I suggest enabling LTO only for the Release builds to not sacrifice the developers' experience during the working on the project since LTO consumes an additional amount of time to finish the compilation routine. If you think that a regular Release build should not be affected by such a change as well, then I suggest adding an additional release-lto profile where additionally to regular release optimizations LTO also will be added. Such a change simplifies life for maintainers and others interested in the project persons who want to build the most performant version of the application.

Possibly there are other projects without LTO - didn't check them all. It would be nice to have LTO enabled by default in some way for all Loco tools.

Thank you.

[jondot]

Hi, yes it makes sense!
I believe if LTO is off we may have experimented with it and left it off. Would you like to submit a PR to fix it?

[zamazan4ik]

I believe if LTO is off we may have experimented with it and left it off.

It's very interesting. If someone can clarify it here - it would be awesome! Probably, there are some known limitations to enabling LTO.

Would you like to submit a PR to fix it?

If I will find free time for doing it :)

[schungx]

Well, I turned on LTO=fat on my small-ish Loco app and it took 3-4 HOURS to link...

I haven't seen a material improvement in speed for the LTO-linked binary...

It is about 1/4 smaller.

[zamazan4ik]

Did you try to use lto = thin instead?

[schungx]

Not really... does it matter? I can try...

[zamazan4ik]

Yeah, ThinLTO is MUCH faster in practice than Fat LTO