I was working some numeric integration stuff when I encountered a lot of small allocations for which I couldn’t find a source for.

Here is a MWE demonstrating the behaviour

```
function f1(f, x)
s = 0.0
for i in 1:2
s += f(x)
end
s
end
function f2(f, x)
s = 0.0
for j in 1:100
s += f1(f, x)
end
s
end
g(x) = @fastmath sqrt(x)
@time f1(g, 1.0)
# no allocations
@time f2(g, 1.0)
# 300 allocations, 4800 bytes
@noinline g2(x) = x
@time f2(g2, 1.0)
# no allocations
```

Looking at `@code_native`

didn’t give any reason to expect allocations.

Although this was not a problem for performance I would really appreciate if someone could explain these allocations.