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Re: [PATCH] Fix PR middle-end/28690, indexed load/store performance + reload bug


Dale Johannesen wrote:
> On Dec 11, 2006, at 12:46 PM, David Edelsohn wrote:
> 
> > 	Hmm.  There don't appear to be many options.  This is just how
> > GCC's current register allocator works.  Another intermediate register
> > class probably would encounter the same problem.
> >
> > 	This patch is okay, but please update the comment above the
> > predicate explaining why accepting anything for reload_in_progress is
> > necessary.
> >
> > Thanks, David
> 
> I'm doubtful a target-specific fix is the right idea.  Don't other  
> targets have the same problem?

Well, the problem itself is target-specific, because the predicate
gpc_register_operand that accepts only certain registers is target-
specific.

I guess one question is, why do you need that predicate in the first
place, and don't just use register_operand?  In particular, given the
issues discussed in this thread, the predicate doesn't appear to have
the intended effect anyway ...

Bye,
Ulrich

-- 
  Dr. Ulrich Weigand
  GNU Toolchain for Linux on System z and Cell BE
  Ulrich.Weigand@de.ibm.com


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