Interesting line in the recent Dr Dobbs article about profiling?

[Gary Willoughby]

I've just read the article over at Dr Dobbs by Walter

http://www.drdobbs.com/cpp/increasing-compiler-speed-by-over-75/240158941

and this line caught my eye:

> Even if you know your code well, you're likely wrong about where
> the performance bottlenecks are. Use a profiler. If you haven't
> used one on your codebase in a while, it's highly likely there's
> a bottleneck in there that's fixable with just a few lines of 
> code.

What profilers do you use with D especially for Linux and Mac? 
I've been compiling with -profile and trying to grok the output.