re PR tree-optimization/69776 (Wrong optimization with aliasing)
2016-02-15 Richard Biener <rguenther@suse.de>
PR tree-optimization/69776
* tree-ssa-sccvn.h (vn_reference_lookup): Adjust prototype.
* tree-ssa-sccvn.c (vn_reference_lookup): Add parameter to
indicate whether we can use TBAA to disambiguate against stores.
Use alias-set zero if not.
(visit_reference_op_store): Do not use TBAA when looking up
redundant stores.
* tree-ssa-pre.c (compute_avail): Use TBAA here.
(eliminate_dom_walker::before_dom_children): But not when looking
up redundant stores.
* gcc.dg/torture/pr69776.c: New testcase.
From-SVN: r233418