pure-ifying my code

[qznc]

On Sunday, 17 November 2013 at 21:00:16 UTC, Jonathan M Davis 
wrote:
> will definitely result in multiple calls to pure_func. It's not 
> that it's
> impossible for the compiler to do it - it's perfectly possible. 
> But doing so
> would require at least basic code flow analysis, and dmd almost 
> never does any
> kind of code flow analysis.

I remember Walter being against flow analysis in the frontend. 
This is middleend optimization stuff, though. Does dmd really use 
no data flow analysis anywhere?