https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64853
--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
--- gcc/tree-vrp.c.jj 2015-01-28 08:39:51.000000000 +0100
+++ gcc/tree-vrp.c 2015-01-29 10:44:37.395688127 +0100
@@ -7093,14 +7093,14 @@ vrp_valueize_1 (tree name)
if (TREE_CODE (name) == SSA_NAME)
{
value_range_t *vr = get_value_range (name);
- if (range_int_cst_singleton_p (vr))
- return vr->min;
/* If the definition may be simulated again we cannot follow
this SSA edge as the SSA propagator does not necessarily
re-visit the use. */
gimple def_stmt = SSA_NAME_DEF_STMT (name);
if (prop_simulate_again_p (def_stmt))
return NULL_TREE;
+ if (range_int_cst_singleton_p (vr))
+ return vr->min;
}
return name;
}
fixes this, even when a VR is singleton, it might be singleton just because it
is singleton only in the first iteration and not afterwards.
That said, I'd worry that this patch might degrade VRP folding too much.
