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Re: Code generation problem with optimizations enabled


Thank you Paolo, I'll take a look at it.
Is there a reason why the fcmp insn was dropped with such implementation?


 - Jamie



----- Original Message ----
> From: Paolo Bonzini <bonzini@gnu.org>
> To: Jamie Prescott <jpresss@yahoo.com>
> Cc: gcc@gcc.gnu.org
> Sent: Tuesday, May 12, 2009 1:31:53 AM
> Subject: Re: Code generation problem with optimizations enabled
> 
> > What I noticed is that if I CC_STATUS_INIT (in xxx_notice_update_cc()) even 
> for insn that
> > do not require it (that are almost all of them - being only cmp/fcmp/test that 
> modify cc0),
> > cmpdf gets emitted regularly.
> 
> If so, you should not be using cc0, but a CCmode register instead.
> 
> See for example how the fr30 port implements compare-and-jump.  I'm
> currently committing a merge that changes a bit how the
> compare-and-jumps are realized; if you wait a few hours, you'll get a
> more up-to-date example.
> 
> Paolo



      


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