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Re: Loop unrolling-related SPEC regressions?
- From: Michael Matz <matzmich at cs dot tu-berlin dot de>
- To: Andreas Jaeger <aj at suse dot de>
- Cc: Dale Johannesen <dalej at apple dot com>, Laurent Guerby <guerby at acm dot org>, Paolo Carlini <pcarlini at unitus dot it>, <gcc at gcc dot gnu dot org>, <rth at redhat dot com>
- Date: Thu, 7 Feb 2002 16:13:56 +0100 (MET)
- Subject: Re: Loop unrolling-related SPEC regressions?
On Thu, 7 Feb 2002, Andreas Jaeger wrote:
> > Intelligent use of profiling info from the first pass is
> > important. You'll see the published numbers do this.
> > Last time I looked gcc used this only for branch
> > straightening; it can also be used effectively to
> > drive inlining and register allocation.
> AFAIK the infrastructure is there, it only needs to be used for
> inlining - and also in the new register allocator. Michal, is this
In fact if the numbers I base decisions in the allocator on, are itself
based on profiling, then the allocator can already be profile-guided.
Basically what I need is only cost estimations for basic blocks (i.e. how
often they are run compared to the other blocks in the function). I don't
care if they are estimated statically from loop structure or precisely