[Bug middle-end/42973] [4.4/4.5 regression] IRA apparently systematically making reload too busy on 2 address instructions with 3 operands

[vmakarov at redhat dot com]

------- Comment #11 from vmakarov at redhat dot com  2010-02-10 17:15 -------

(In reply to comment #8)
> 
> Thanks, we should see if this solves the AMMP problem in a day or two.
> Are you going to look at the related PR42961?  Without the regmove hunk
> it does not happen at AMMP but it likely happens elsewhere.  I did some
> work on this years back on old RA so I can play with it too.
> (Simple fix would be to add ? penalizers to integer variant of FP moves,
> but I would like to see some solution where RA actually can use integers
> for mem->mem copies)

  I am working on IRA without usage of cover classes.  For example, IRA could
assign integer or floating point register for mem->mem copies whatever is
possible and whatever is more profitable.  This code is big and not ready yet. 
There are a lot of performance issues (besides IRA speed issues which is a
consequence of dealing with more classes).  I am trying to solve the issues. 
But if the code is ok, it probably will solve the problem.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42973