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[Bug tree-optimization/15524] [4.0 Regression] jump threading on trees is slow with switch statements with large # of cases
- From: "stevenb at suse dot de" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 1 Nov 2004 20:17:31 -0000
- Subject: [Bug tree-optimization/15524] [4.0 Regression] jump threading on trees is slow with switch statements with large # of cases
- References: <20040518194300.15524.pinskia@gcc.gnu.org>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Additional Comments From stevenb at suse dot de 2004-11-01 20:17 -------
Subject: Re: [4.0 Regression] jump threading on trees is slow with switch statements with large # of cases
> I think it'll ultimately be cleaner to simply drop the labels after
> we've built the CFG and associate an edge with each of the cases.
Yes, this is what I would really want to do, but I don't know if such
a patch would be safe for GCC 4.0. I suppose we could introduce a fake
'x' class tree with is really just a VEC(edge) plus a tree_common, and
stuff that into SWITCH_LABELS (which would at that point not longer be
an appropriate name of course ;-). The trouble is that we still need
to recreate the labels for expand, that's the ugly part.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15524