result code = -1
standard error = {
tests/diagnostics/autodiff-data-flow-2.slang(17): error 41020: derivative cannot be propagated through call to non-backward-differentiable function `f`, use 'no_diff' to clarify intention.
    float val = f(x + 1); // Error: f must also be backward-differentiable
                 ^
tests/diagnostics/autodiff-data-flow-2.slang(29): error 30510: loops inside a differentiable function need to provide either '[MaxIters(n)]' or '[ForceUnroll]' attribute.
    for (int i = 0; i < (int)x; i++)
    ^~~
}
standard output = {
}