https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118867
--- Comment #16 from Andrew Pinski <pinskia at gcc dot gnu.org> --- Created attachment 60503 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=60503&action=edit Patch for the canonical of variants (In reply to Richard Biener from comment #14) > We have helpers for folding compares that canonicalize on the fly - we are > nowhere canonializing such ADDR_EXPRs (to &MEM[&decl + CST]) because of > object-size and late diagnostics. > > VN _should_ have figured this though by means of predication > > _30 = listJets.D.31591._M_impl._M_node.D.14392._M_next; > if (&listJets.D.31591._M_impl._M_node.D.14392 == _30) > goto <bb 19>; [5.50%] > else > goto <bb 9>; [94.50%] -> register > &listJets.D.31591._M_impl._M_node.D.14392 != _30 > > <bb 9> [local count: 118111600]: > if (&MEM[(struct _List_node_header *)&listJets].D.14392 != _30) > > -> find it. Unless there are other edges into BB 9, of course, in which > case jump-threading is required and likely ranger / relations do not > record "canonialized" ADDR_EXPRs. So one issue with FRE/PRE not figuring out on the predicates is due to the SSA_NAME NOT being last. that is insert_predicates_for_cond does nothing is the LHS is NOT a SSA_NAME. This attached patch fixes that. and now we get: Recording on edge 2->3 a_5 eq_expr &MEM[(struct s2 *)&t].t.node == true Recording on edge 2->4 a_5 eq_expr &MEM[(struct s2 *)&t].t.node == false Recording on edge 2->3 a_5 ne_expr &MEM[(struct s2 *)&t].t.node == false Recording on edge 2->4 a_5 ne_expr &MEM[(struct s2 *)&t].t.node == true But then don't record "canonialized" ADDR_EXPRs nor lookup those up.
