multiple_of_p change

[Jeffrey A Law]

  In message <199710242313.BAA08816@Rivendell.MiddleEarth.net>you write:
  > During the processing, the subreg case around line 7390 of cse.c is entered.
  > a classp is found, and its exp field is (subreg:SI (reg/v:SF 35) 0).  At the 
  > next loop iteration, new_src is set from gen_lowpart_if_possible to the same
  > expression (subreg:SI (reg/v:SF 35) 0).
  > The *bad* thing is that HASH produces a different value than it did when 
  > classp->exp was hashed.
OK.  This is where I'd suggest you concentrate your effort -- figure
out how/why the same RTL hashes differently from the two different
call sites.

jeff