[Bug tree-optimization/42906] [4.5 Regression] Empty loop not removed

[steven at gcc dot gnu dot org]

------- Comment #3 from steven at gcc dot gnu dot org  2010-01-30 16:45 -------
Hack that may be worth trying:
Index: tree-ssa-dce.c
===================================================================
--- tree-ssa-dce.c      (revision 156352)
+++ tree-ssa-dce.c      (working copy)
@@ -683,7 +683,10 @@ propagate_necessity (struct edge_list *e
            {
              for (k = 0; k < gimple_phi_num_args (stmt); k++)
                {
+                 tree t = gimple_phi_arg_def (stmt, k);
                  basic_block arg_bb = gimple_phi_arg_edge (stmt, k)->src;
+                 if (is_gimple_min_invariant (t))
+                   continue;
                  if (arg_bb != ENTRY_BLOCK_PTR
                      && ! TEST_BIT (visited_control_parents, arg_bb->index))
                    {


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42906