Fix recursive structure and setup precompilation

[ChrisRackauckas]

The recursive structure of SystemStructure was giving precompilation an issue so I removed that module. Then I setup precompilation on the basic interface. Test case:

@time using ModelingToolkit
@time using DifferentialEquations
@time using Plots
@time begin
    @variables t x(t)
    D = Differential(t)
    @named sys = ODESystem([D(x) ~ -x])
end;
@time prob = ODEProblem(structural_simplify(sys), [x => 30.0], (0, 100), [], jac = true);
@time sol = solve(prob);
@time plot(sol, idxs=[x]);

Before:

11.082586 seconds (19.32 M allocations: 1.098 GiB, 4.09% gc time, 0.71% compilation time: 87% of which was recompilation)
0.639738 seconds (661.39 k allocations: 101.321 MiB, 4.33% gc time, 6.46% compilation time)
3.703724 seconds (5.71 M allocations: 322.840 MiB, 5.22% gc time, 9.92% compilation time: 86% of which was recompilation)
7.795297 seconds (8.25 M allocations: 483.041 MiB, 2.50% gc time, 99.88% compilation time)
21.719376 seconds (44.11 M allocations: 2.485 GiB, 5.68% gc time, 99.48% compilation time)
2.602250 seconds (4.04 M allocations: 253.058 MiB, 4.60% gc time, 99.90% compilation time)
2.450509 seconds (5.17 M allocations: 332.101 MiB, 5.89% gc time, 99.41% compilation time: 30% of which was recompilation)

After:

9.129141 seconds (22.77 M allocations: 1.291 GiB, 4.65% gc time, 0.62% compilation time: 87% of which was recompilation)
0.784464 seconds (667.59 k allocations: 101.524 MiB, 3.95% gc time, 4.16% compilation time)
3.111142 seconds (5.42 M allocations: 305.594 MiB, 3.82% gc time, 6.39% compilation time: 82% of which was recompilation)
0.105567 seconds (157.39 k allocations: 10.522 MiB, 8.81% gc time, 95.49% compilation time: 74% of which was recompilation)
1.993642 seconds (4.03 M allocations: 218.310 MiB, 2.69% gc time, 96.95% compilation time: 82% of which was recompilation)
1.806758 seconds (4.06 M allocations: 254.371 MiB, 4.44% gc time, 99.91% compilation time)
1.694666 seconds (5.27 M allocations: 339.088 MiB, 6.18% gc time, 99.39% compilation time: 31% of which was recompilation)

And that's on v1.9, so v1.10 should be even better. 20 seconds off hehe.

[YingboMa]

Is this deliberate? It would be slightly breaking.

[ChrisRackauckas]

It is deliberate. How is it breaking?

[YingboMa]

It will break ModelingToolkit.X as a shorthand for ModelingToolkit.SystemStructures.X. Can we use it at least after precompilation?

[ChrisRackauckas]

SystemStructures is no longer a module.

[YingboMa]

Ah, well, it's breaking when people actually do ModelingToolkit.SystemStructures.X then 😅.

[ChrisRackauckas]

That's not public... right?

[ChrisRackauckas]

v1.10 is nice:

  3.200767 seconds (4.81 M allocations: 301.123 MiB, 2.37% gc time, 0.55% compilation time)
  0.165489 seconds (168.82 k allocations: 10.458 MiB, 17.35% compilation time)
  1.053160 seconds (1.76 M allocations: 98.635 MiB, 3.62% gc time, 15.93% compilation time: 80% of which was recompilation)
  0.317384 seconds (901.99 k allocations: 59.005 MiB, 99.53% compilation time: 88% of which was recompilation)
  1.851974 seconds (3.11 M allocations: 208.672 MiB, 1.25% gc time, 99.41% compilation time: 90% of which was recompilation)
  1.969298 seconds (3.64 M allocations: 244.764 MiB, 0.66% gc time, 99.97% compilation time)
  1.640871 seconds (4.28 M allocations: 289.529 MiB, 2.00% gc time, 99.69% compilation time: 18% of which was recompilation)