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Re: -fprofile-generate and -fprofile-use
Hi Janis,
janis187@us.ibm.com (Janis Johnson) wrote on 01.09.05 in <20050901225348.GA6845@us.ibm.com>:
[quoteto.xps]
> On Thu, Sep 01, 2005 at 11:45:35PM +0200, Steven Bosscher wrote:
> > On Thursday 01 September 2005 23:19, girish vaitheeswaran wrote:
> > > Sorry I still did not follow. This is what I
> > > understood. During Feedback optimization apart from
> > > the -fprofile-generate, one needs to turn on
> > > -fmove-loop-invariants.
> >
> > You don't "need to". It just might help iff you are using a gcc 4.1
> > based compiler.
> >
> > > However this option is not
> > > recognized by the gcc 3.4.4 or 3.4.3 compilers. What
> > > am I missing?
> >
> > You are missing that
> > 1) this whole thread does not concern gcc 3.4.x; and
> > 2) the option -fmove-loop-invariants does not exist in 3.4.x.
>
> Girish started this thread about problems he is seeing with GCC 3.4.3
The discussion, maybe. The thread, definitely not - that was started by
Peter Steinmetz (new subject, no References:). And it was explicitely
about "using mainline":
] There was some discussion a few weeks ago about some apps running slower
] with FDO enabled.
...
] While this doesn't explain all of the degradations discussed (some were
] showing up on older versions of the compiler), it may explain some.
MfG Kai