Gcc 3.1 performance regressions with respect to 2.95.3

[law@redhat.com]

I'm trying to pick up this thread and get some resolution on this issue.  So
forgive me if we end up rehashing anything.

 In message <200204252212.SAA22194@makai.watson.ibm.com>, David Edelsohn 
writes:
 > 	Sigh^2.  The open-coded no-conflict block does not work as a
 > normal no-conflict block.  This algorithm probably is not strictly a word
 > at a time, so no-conflict causes optimization errors down the line.
Bummer.  Are we still going to need the naked clobber though?  Presumably we
have it for flow's benefit?

 > 	I guess one other question is why the target REG is re-used
 > instead of a new pseudo generated.  That also would prevent the DEAD notes
 > from disappearing.
If you can safely use a new pseudo that would be preferable; various early
passes in the compiler try to be sensitive to the needs of 2 address
architectures (x86, m68k, etc) and sometimes re-use pseudos.  However, I
think that's exposing target details far earlier than is advantageous.  So
I'm all for generating a new pseudo.

jeff