------- Comment #4 from rguenth at gcc dot gnu dot org 2007-06-21 10:38 -------
The problem is introduced by tree-ssa-threadupdate.c:thread_single_edge where
we have the single_pred_p case but fail to clear the edge flags as we do
for example in DOMs propagate_rhs_into_lhs. So the following seems to work
but I'm not sure if this is enough:
Index: tree-ssa-threadupdate.c
===================================================================
--- tree-ssa-threadupdate.c (revision 125884)
+++ tree-ssa-threadupdate.c (working copy)
@@ -636,6 +636,9 @@ thread_single_edge (edge e)
/* If BB has just a single predecessor, we should only remove the
control statements at its end, and successors except for ETO. */
remove_ctrl_stmt_and_useless_edges (bb, eto->dest);
+ eto->flags &= ~(EDGE_TRUE_VALUE | EDGE_FALSE_VALUE);
+ eto->flags &= ~EDGE_ABNORMAL;
+ eto->flags |= EDGE_FALLTHRU;
return bb;
}
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32451
