tree-optimization/113080 - missing final value replacement
When performing final value replacement we guard against exponential
(temporary) code growth due to unsharing of trees (SCEV heavily
relies on tree sharing). The following relaxes this a tiny bit
to cover some more optimizations and puts in comments as to what
the real fix would be.
PR tree-optimization/113080
* tree-scalar-evolution.cc (expression_expensive_p): Allow
a tiny bit of growth due to expansion of shared trees.
(final_value_replacement_loop): Add comment.
* gcc.dg/tree-ssa/sccp-3.c: New testcase.