I encountered a performance issue whilst working. I’ve managed to produce a minimal example of my code that reproduces a performance issue. I have a file bug.jl:

```
import QuadGK
function inner_integrand()
function integrand(t :: Float64)
return 0.1
end
term1 = QuadGK.quadgk(integrand, 1, 2)[1]
return term1
end
function outer_integrand()
p = inner_integrand()
return 0.5
end
function evaluate_double_integral()
function integrand(theta_0)
return outer_integrand()
end
return QuadGK.quadgk(integrand, 0, 0.1)[1]
end
function compute_solution()
println("Inside computation function")
integro_diff_mtrx =
map(
in->evaluate_double_integral(),
[0]
)
println("Finished computation function")
return
end
```

I can use this with a script, testa.jl:

```
include("bug.jl")
println("Before computation function")
compute_solution()
println("After computation function")
```

I can run this from the command line: julia.exe testa.jl.

It takes a whole minute and 21 seconds to run.

Oddly, I can make it run much faster by making evaluating the inner integrand once before we attempt the double integral: testb.jl:

```
include("bug.jl")
println("Evaluating a function pointlessly.")
inner_integrand()
println("Before computation function")
compute_solution()
println("After computation function")
```

Now it takes 1.6 seconds. Much faster (but still surprisingly slow?).

Does this count as a bug, or is there something I’m missing?

I’m using Windows 10 x64. Issue in Julia 1.0.3.