strange "a la m32r" comment in cgen-dis.in

[Doug Evans]

I don't understand the "possibly modified" part of this comment.

cgen-dis.in:
  /* Fill in ex_info fields like read_insn would.  Don't actually call
     read_insn, since the incoming buffer is already read (and possibly
     modified a la m32r).  */

Can you elaborate?

A pointer to the place that possibly modifies the incoming buffer
is sufficient.  My poor eyes can't find it.