DMD Source Hot Spot for Expression Type Deduction

[Nordlöw]

I'm looking for hot spots in the DMD source where deduction of 
types of expressions are performed.

I want to use this to extract information about the type of an 
expression before/after point.

Is this logic spread all over

.*Exp::semantic
.*Exp::semantic2
.*Exp::semantic3

or is there a hot spot where I can insert a callback to print 
such information?