implicit integer casts

[Tachio Terauchi]

Hi,

I'm trying to find where, if any, the implicit integer casts are made
explicit in the gcc compiler.  I noticed that in some case (int ->
short), using gcc -dr, RTL shows something, but for some other case
(unsigned int -> int) RTL shows nothing.  This seems to imply that I
need to look at a pass prior to the creation of RTL to detect certain
implicit integer casts.  Does anyone have prior experience with this?
Any help would be apprieciated...

-Tachio