LLVM under wine is excruciatingly slow

[Keno]

We now have the ability to build Julia again under Wine. However, the final LLVM step during bootstrap is excruciatingly slow. It was never particularly fast, but it seems to have gotten significantly slower. If I interrupt the process in the debugger, all of the time appears to be in malloc, so it's possible that Wine's malloc implementation is just slow, but we should look into it.

[Keno]

Unfortunately, this appears to be specific to running under Julia. If I dump out the .bc and then run llc directly, it finishes in a reasonable amount of time.

[Keno]

I got myself a faster machine and can confirm it does finish eventually:

Generation ?? 107.022640 seconds 73.125%
Execution ???  39.333203 seconds 26.875%
Total ??????? 146.355844 seconds
Outputting sysimage file...
Output ?????? 1117.981631 seconds
    LINK usr/lib/julia/sys.dll

Still it's about 2-3x slower than expected. I'd expect about ~300s-400s, which is what I do see if I run both LLVM and julia separately.

[DilumAluthge]

Out of curiosity, what's the total wall time of the entire build?

[Keno]

~20 minutes

[giordano]

If you think that's slow, go and build Julia on A64FX: https://github.com/giordano/julia-on-fugaku/blob/256d4f34e5cdeea7748a25dd9f3e15f547abf19c/README.md#with-gcc

[gbaraldi]

Removing precompilation helps a bit but it seems we hit a pathological case.

[romanrexc]

The situation seems to be better now (Julia master, Wine 10.0 + few patches):

Precompilation complete. Summary:
Total ???????   5.156260 seconds
Outputting sysimage file...
Output ?????? 200.597832 seconds
    LINK julia-mingw-w64/usr/lib/julia/sys.dll
    JULIA julia-mingw-w64/stdlib/release.image