Document options to get fastest compile times?

[Philipp15b]

Hello Team Storm! Are there documented options to get Storm to compile as fast as possible? As far as I can see, the only option to get Storm to compile faster is disabling LTO - but e.g. disabling some compiler optimizations might also be very helpful during development. In addition, we've seen with Caesar that switching to a more modern linker such as ldd/mold can speed up the linking process by a lot.

This issue is not the same as #443, because I'm only focused on speeding up incremental builds during development, not the full builds with all optimizations enabled.

[volkm]

In my experience, disabling lto is indeed helpful. For incremental builds, the most important option is usually using ccache which helps quite a lot.

Another option is cleaning-up includes such that changing one file does not require rebuilding dozens of other files. But I think @sjunges made already good progress there.

I tried using mold here, but preliminary timings were not conclusive yet. But you can use it as a starting point for mold.

[sjunges]

The main trick during development I have is no LTO and being mindful which files you touch. For larger development efforts, I try to not compile the storm main library if I can somehow organise it.

If you could run the profiler as described in #433 for a typical development cycle of yours, we can also see what is going on :-)

[Philipp15b]

A fresh compile run with cmake .. -DSTORM_FORCE_SHIPPED_CARL=ON -DSTORM_USE_CLN_EA=OFF -DSTORM_USE_CLN_RF=OFF and time make -j8 on my Macbook M1 Pro took about 7min 45s.

With STORM_DEVELOPER, No LTO, and using the ninja build system instead of make, I got the times down to 6min 38s. Simply using ninja instead of make already saved more than 20s.
These were the commands I used:

cmake .. -DSTORM_FORCE_SHIPPED_CARL=ON -DSTORM_USE_CLN_EA=OFF -DSTORM_USE_CLN_RF=OFF -DSTORM_DEVELOPER=ON -DSTORM_USE_LTO=OFF -G Ninja
time ninja

We'll try do run similar experiments on a slow Windows machine with WSL and using mold, I'm hoping for some even bigger speedups.

@sjunges Are you sure you mean #433? Which profiler do you mean?

[sjunges]

Ah, sorry, i meant #443. In particular, there is a comment by MV that also clarifies how to run the compile time profiler.

Other things that help:

• ccache helps a bit for me.
• It helps to not build everything, but only build the target that you want. I guess you only want to build the main binaries, so something like storm-cli would do.