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Re: [trunk<-vta] Re: [vtab] Permit coalescing of user variables


On Jun  3, 2009, Richard Guenther <richard.guenther@gmail.com> wrote:

> Btw, _is_ there really a such big effect with enabling the extra coalescing?

I'm pretty sure I even posted SPEC results back when I first proposed
these changes.

I remember there was a huge effect in compile time for some
machine-generated sources.  Surely if enabling coalescing for inlined
variables had such a huge effect, enabling it for non-inlined variables
would have an even larger effect.

Difference in performance was nothing to write home about, but when
you're trying to squeeze the last bit of performance from a program,
losing it to debug info you're not even interested in doesn't speak well
of GCC.

-- 
Alexandre Oliva, freedom fighter    http://FSFLA.org/~lxoliva/
You must be the change you wish to see in the world. -- Gandhi
Be Free! -- http://FSFLA.org/   FSF Latin America board member
Free Software Evangelist      Red Hat Brazil Compiler Engineer


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