I am testing the following patch to avoid useless VRP range allocations
when we just ask for varying on stmts we don't know how to handle.
I think it should fix the PR where we end up assigning to the
static const vr_const_varying returned by get_value_range in the early VRP
context.
Eventually the VRP lattice needs to become sparse (or just growable, I
have a patch for that as well). Not until early VRP gets some more
capabilities though, it would be a waste otherwise.
Bootstrap / regtest in progress on x86_64-unknown-linux-gnu.
Richard.
2016-09-28 Richard Biener <rguent...@suse.de>
* tree-vrp.c (set_defs_to_varying): New helper.
(vrp_initialize): Call it.
(vrp_visit_stmt): Likewise.
(evrp_dom_walker::before_dom_children): Likewise.
Index: gcc/tree-vrp.c
===================================================================
--- gcc/tree-vrp.c (revision 240568)
+++ gcc/tree-vrp.c (working copy)
@@ -343,6 +343,24 @@ set_value_range_to_varying (value_range
}
+/* Set value-ranges of all SSA names defined by STMT to varying. */
+
+static void
+set_defs_to_varying (gimple *stmt)
+{
+ ssa_op_iter i;
+ tree def;
+ FOR_EACH_SSA_TREE_OPERAND (def, stmt, i, SSA_OP_DEF)
+ {
+ unsigned ver = SSA_NAME_VERSION (def);
+ /* Avoid needlessly allocating value-ranges. */
+ if (num_vr_values >= ver
+ && vr_value[ver])
+ set_value_range_to_varying (vr_value[ver]);
+ }
+}
+
+
/* Set value range VR to {T, MIN, MAX, EQUIV}. */
static void
@@ -7022,10 +7040,7 @@ vrp_initialize ()
prop_set_simulate_again (stmt, true);
else if (!stmt_interesting_for_vrp (stmt))
{
- ssa_op_iter i;
- tree def;
- FOR_EACH_SSA_TREE_OPERAND (def, stmt, i, SSA_OP_DEF)
- set_value_range_to_varying (get_value_range (def));
+ set_defs_to_varying (stmt);
prop_set_simulate_again (stmt, false);
}
else
@@ -7901,8 +7916,6 @@ vrp_visit_stmt (gimple *stmt, edge *take
{
value_range vr = VR_INITIALIZER;
tree lhs = gimple_get_lhs (stmt);
- tree def;
- ssa_op_iter iter;
extract_range_from_stmt (stmt, taken_edge_p, output_p, &vr);
if (*output_p)
@@ -7997,8 +8010,7 @@ vrp_visit_stmt (gimple *stmt, edge *take
/* All other statements produce nothing of interest for VRP, so mark
their outputs varying and prevent further simulation. */
- FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_DEF)
- set_value_range_to_varying (get_value_range (def));
+ set_defs_to_varying (stmt);
return (*taken_edge_p) ? SSA_PROP_INTERESTING : SSA_PROP_VARYING;
}
@@ -10726,12 +10738,7 @@ evrp_dom_walker::before_dom_children (ba
&& (vr.type == VR_RANGE || vr.type == VR_ANTI_RANGE))
update_value_range (output, &vr);
else
- {
- tree def;
- ssa_op_iter iter;
- FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_DEF)
- set_value_range_to_varying (get_value_range (def));
- }
+ set_defs_to_varying (stmt);
/* Try folding stmts with the VR discovered. */
bool did_replace
@@ -10780,12 +10787,7 @@ evrp_dom_walker::before_dom_children (ba
}
}
else
- {
- tree def;
- ssa_op_iter iter;
- FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_DEF)
- set_value_range_to_varying (get_value_range (def));
- }
+ set_defs_to_varying (stmt);
}
bb->flags |= BB_VISITED;
return NULL;
