Re: -fssa-dce fails on HAVE_cc0 port?

[law at redhat dot com]

  In message <d77j467a.fsf@localhost.localdomain>you write:
  > apl@alum.mit.edu writes:
  > 
  > > It looks like we're deleting CC0 setters in the SSA passes.  This
  > > results in the compiler crashing in cse when fold_rtx stumbles over
  > > the fact that nobody set the cc0 value that's being tested for a
  > > conditional branch.
  > > 
  > > If this is news to the SSA developers, I can see about providing a test
  > > case.
  > > 
  > > I stumbled on this by asserting
  > > 
  > >   -Os -fssa -fssa-dce
  > > 
  > > to the port I'm doing.  I don't know if this will cause any released
  > > ports to crash or not.
  > 
  > I have sended a bugfix few weeks ago few times.
  > But my patch was ignored. :(
  > I don't know why.
Probably because folks were concentrating on gcc-3.0 as they should have
been doing :-)

I'll review it now.  Please do not install it.  I believe it is imperative
that we not start introducing code to deal with this kind of target
dependency into the SSA optimizers.

SSA is experimental work.  If you can't deal with the aborts or wrong code,
then don't use it :-)
jeff