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Re: optimization/6007: cfg cleanup tremendous performance hog with -O1
- From: Jan Hubicka <jh at suse dot cz>
- To: Brad Lucier <lucier at math dot purdue dot edu>
- Cc: Jan Hubicka <jh at suse dot cz>, David Edelsohn <dje at watson dot ibm dot com>, gcc at gcc dot gnu dot org, mark at codesourcery dot com, feeley at iro dot umontreal dot ca
- Date: Mon, 25 Mar 2002 09:41:09 +0100
- Subject: Re: optimization/6007: cfg cleanup tremendous performance hog with -O1
- References: <20020322114115.GM22936@atrey.karlin.mff.cuni.cz> <200203250159.g2P1xGG24661@banach.math.purdue.edu>
> [RE: crossjumping]
>
> > I will try to check whether I can squeze out some more cycles or
> > find way how to limit this.
>
> My code uses a lot of computed goto's, with many labels. Is crossjumping
> possibly a win in this case? Can it ignore these jumps?
I personally don't think that the computed jumps makes some important difference
from crossjumping effectivity point of view. ONly they makes the graph very
huge making it dificult to find the crossjumping candidates.
The graph is already n^2 in size and I need to find matching outgoing edges
running tiny loop as n^3 that probably makes difference. As there is no
particular ordering of edges, I am not sure if and how I can reduce the
complexity. I will try to check this till end of week ( I have bit too many
things on my TODO unforutnately, so hope to get into soon, but don't know
exactly when :( )
Honza
>
> Brad