ABI and exception handling

[Lionello Lunesu]

I came across an interesting article:

http://blogs.msdn.com/freik/archive/2005/03/17/398200.aspx

and I was wondering if it would be possible to use a calling convention 
similar to x64's "__fastcall" for D programs? Apparently there should be a 
speed-up, especially when using exception handling (or those new 
on_scope_xxx constructs).

Or is D "obliged" to use the C calling convention? I wouldn't think so, 
since what's the point of "extern(C)" in that case, for the decoration?

L.