PATCH: VAX sltu and sgeu patterns

Jeffrey A Law
Mon Aug 21 07:25:00 GMT 2000

  In message < >you write:
  > The patch fixes the reload problem arising from non offsettable memory.
  > I havn't observed any input reloads arising from the failure of a pseudo
  > to get a hard register.  If this is a significant problem, then it appears
  > other ports such as m68k are also affected.
Then they need to be fixed too.

  > >   > None of our other cc0 ports need this, that I recall.
  > > That's what we used to do for conditional moves on the ia32 port until
  > > we changed it not to use cc0 if I remember correctly.
  > This would be a fairly major change.  I would suggest that the patch be
  > installed, and then after further testing, consideration be given as to
  > whether further the above suggestion is implemented.
No, that's just papering over the bug.  The cc0 setter and user must not
ever be separated.  That means that a cc0 user must never, ever ever need
an input reload.  If a pattern exists that can potentially need an input 
reload on such a machine, then that pattern is wrong, plain and simple.


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