This was fun to track down

[Jeffrey A Law]

  In message < 199709232053.WAA03509@squid.pdc.kth.se >you write:
  > 1. It seems strange that convert_modes put a constant into a register.
  >    Maybe that is a bug.
convert_modes has always put a constant into a reg if it couldn't
make find any other way to change the mode of the constant.  This
is nothing new.

I believe this can happen when you need to truncate from one
mode to another, but such truncations are not "nops" -- ie they
need real instructions.

There's probably similar situations when extending a constant
from one mode to another.

I think it's safe to say that convert_modes is doing the correct
thing.


  > 2. If convert_modes is really right, the proper fix to expand_divmod
  >    would be to avoid calling it when op1 is constant.
I don't think you can just avoid the call -- you can't just
operate on constants without any regard to their size.  That's
one of the things that gets us in trouble so often with
64bit targets.


jeff