[Bug tree-optimization/32825] Reduction with nonzero start (arbitrary also) causes an extra add to happen

["dorit at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #3 from dorit at gcc dot gnu dot org  2007-07-24 13:05 -------
(In reply to comment #1)
> ... We actually had both options in the vectorizer for a while
> (guarded by ADJUST_IN_EPILOG hard-coded #define), however we didn't know how to
> choose between the two options (cost wise), so we just arbitrarily chose one.
> Now that we're starting to build a cost model we may try to evaluate which of
> the two options to generate. 

for the record - this was the patch that removed the second option:

2007-04-18  Dorit Nuzman  <dorit@il.ibm.com>

        * tree-vect-transform.c (get_initial_def_for_reduction): Clean away
        the unused code for reduction without adjust-in-epilog to simplify the
        function.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32825