This turns the switch (which also requires propagating into ASSERT_EXPRs,
otherwise those will end up with released SSA names eventually).
A [3/2] would be to let ASSERT_EXPRs be removed by the propagator
which would a) require VRP to fix up its lattice for this task,
b) make match-and-simplify not be confused by them during
substitute-and-fold folding. This also requires (I think) dealing
with symbolic valueizations during substitute-and-fold in a
way FRE does (track availability) -- currently propagators restrict
themselves to constants due to that (avoid substituting to where
the use does not dominate the definition).
Re-bootstrap / regtest pending on x86_64-unknown-linux-gnu.
Richard.
2016-10-07 Richard Biener <rguent...@suse.de>
* tree-ssa-propagate.c
(substitute_and_fold_dom_walker::before_dom_children): Do not
ignore ASSERT_EXPRs.
* tree-vrp.c (remove_range_assertions): Deal with ASSERT_EXPRs
that have been propagated into.
(vrp_finalize): Enable DCE for substitute_and_fold.
Index: gcc/tree-ssa-propagate.c
===================================================================
--- gcc/tree-ssa-propagate.c (revision 240855)
+++ gcc/tree-ssa-propagate.c (working copy)
@@ -1049,15 +1049,6 @@ substitute_and_fold_dom_walker::before_d
{
bool did_replace;
gimple *stmt = gsi_stmt (i);
- enum gimple_code code = gimple_code (stmt);
-
- /* Ignore ASSERT_EXPRs. They are used by VRP to generate
- range information for names and they are discarded
- afterwards. */
-
- if (code == GIMPLE_ASSIGN
- && TREE_CODE (gimple_assign_rhs1 (stmt)) == ASSERT_EXPR)
- continue;
/* No point propagating into a stmt we have a value for we
can propagate into all uses. Mark it for removal instead. */
Index: gcc/tree-vrp.c
===================================================================
--- gcc/tree-vrp.c (revision 240855)
+++ gcc/tree-vrp.c (working copy)
@@ -6894,9 +6894,9 @@ remove_range_assertions (void)
imm_use_iterator iter;
var = ASSERT_EXPR_VAR (rhs);
- gcc_assert (TREE_CODE (var) == SSA_NAME);
- if (!POINTER_TYPE_P (TREE_TYPE (lhs))
+ if (TREE_CODE (var) == SSA_NAME
+ && !POINTER_TYPE_P (TREE_TYPE (lhs))
&& SSA_NAME_RANGE_INFO (lhs))
{
if (is_unreachable == -1)
@@ -6928,8 +6928,11 @@ remove_range_assertions (void)
/* Propagate the RHS into every use of the LHS. */
FOR_EACH_IMM_USE_STMT (use_stmt, iter, lhs)
- FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
- SET_USE (use_p, var);
+ {
+ FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
+ SET_USE (use_p, var);
+ update_stmt (use_stmt);
+ }
/* And finally, remove the copy, it is not needed. */
gsi_remove (&si, true);
@@ -10608,7 +10611,7 @@ vrp_finalize (bool warn_array_bounds_p)
}
substitute_and_fold (op_with_constant_singleton_value_range,
- vrp_fold_stmt, false);
+ vrp_fold_stmt, true);
if (warn_array_bounds && warn_array_bounds_p)
check_all_array_refs ();
