This is the mail archive of the
mailing list for the GCC project.
[Bug tree-optimization/19590] IVs with the same evolution not eliminated
- From: "steven at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 14 Nov 2005 10:32:44 -0000
- Subject: [Bug tree-optimization/19590] IVs with the same evolution not eliminated
- References: <email@example.com/bugzilla/>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Comment #7 from steven at gcc dot gnu dot org 2005-11-14 10:32 -------
It would be more interesting to measure than think ;-)
My experience is that when it is in Briggs' test suite, it usually also happens
in actually useful code. But, only the numbers will tell :-)
Zdenek is right, it's just a matter of comparing the evolutions of loop PHI
nodes. Instrumenting the compiler to count how often this happens is half the
work of implementing the optimization if it turns out to be useful.