C++ compile-time regressions

[Joe Buck]

Alexandre:
> > I suppose it would be desirable to inline pretty much the
> > same functions, regardless of the target.

Mark:
> Yes, I suppose -- although if a function really is going to take up
> twice as much icache on one platform as another, it might be a less
> promising inlining candidate.

The compiler doesn't know the size of the user's icache, so it's hard
to make these tradeoffs: processors with lower instruction density might
well use bigger icaches to compensate.

> If you run some numbers and can show it's a win, then I think that's
> good.  I wouldn't commit it without demonstrating the win, though.

Agreed, we need numbers.  Gerald's tests are one source of inputs; there
also may be some code in Boost that could be used.