tree-optimization/110204 - second level redundancy and simplification

When PRE discovers a full redundancy during insertion it cannot unite
the two value sets.  Instead it inserts a copy old-val = new-val where
new-val can also be a constant.  The following looks through such
copies during elimination, providing one extra level of constant and
copy propagation.  For the PR this helps avoiding a bogus diagnostic
that's emitted on unreachable code during loop optimization.

	PR tree-optimization/110204
	* tree-ssa-sccvn.cc (eliminate_dom_walker::eliminate_avail):
	Look through copies generated by PRE.

0 files changed, 0 insertions, 0 deletions