https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93946
--- Comment #7 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Richard Guenther <rgue...@gcc.gnu.org>: https://gcc.gnu.org/g:3d6fd7ce6dc4b6baa11920387d62dc001980aa70 commit r10-6993-g3d6fd7ce6dc4b6baa11920387d62dc001980aa70 Author: Richard Biener <rguent...@suse.de> Date: Tue Mar 3 11:01:09 2020 +0100 tree-optimization/93946 - fix bogus redundant store removal in FRE, DSE and DOM This fixes a common mistake in removing a store that looks redudnant but is not because it changes the dynamic type of the memory and thus makes a difference for following loads with TBAA. 2020-03-03 Richard Biener <rguent...@suse.de> PR tree-optimization/93946 * alias.h (refs_same_for_tbaa_p): Declare. * alias.c (refs_same_for_tbaa_p): New function. * tree-ssa-alias.c (ao_ref_alias_set): For a NULL ref return zero. * tree-ssa-scopedtables.h (avail_exprs_stack::lookup_avail_expr): Add output argument giving access to the hashtable entry. * tree-ssa-scopedtables.c (avail_exprs_stack::lookup_avail_expr): Likewise. * tree-ssa-dom.c: Include alias.h. (dom_opt_dom_walker::optimize_stmt): Validate TBAA state before removing redundant store. * tree-ssa-sccvn.h (vn_reference_s::base_set): New member. (ao_ref_init_from_vn_reference): Adjust prototype. (vn_reference_lookup_pieces): Likewise. (vn_reference_insert_pieces): Likewise. * tree-ssa-sccvn.c: Track base alias set in addition to alias set everywhere. (eliminate_dom_walker::eliminate_stmt): Also check base alias set when removing redundant stores. (visit_reference_op_store): Likewise. * dse.c (record_store): Adjust valdity check for redundant store removal. * gcc.dg/torture/pr93946-1.c: New testcase. * gcc.dg/torture/pr93946-2.c: Likewise.
