diff --git a/gcc/testsuite/g++.dg/torture/phi-1.C b/gcc/testsuite/g++.dg/torture/phi-1.C
new file mode 100644
index 00000000000..69fb3d7ba38
--- /dev/null
+++ b/gcc/testsuite/g++.dg/torture/phi-1.C
@@ -0,0 +1,28 @@
+// { dg-do compile { target c++11 } }
+// { dg-options "--param early-inlining-insns=14" }
+
+struct Element;
+template <int _Nm> struct __array_traits { typedef Element _Type[_Nm]; };
+template <int _Nm> struct array {
+ typename __array_traits<_Nm>::_Type _M_elems;
+};
+bool logLevel();
+struct LogCapture {
+ void stream();
+};
+struct Element {
+ Element();
+ long data_;
+};
+using ElementArray = array<6>;
+struct ElementManager {
+ ElementManager();
+ ElementArray array_;
+};
+static ElementArray makeArray() {
+ if (logLevel())
+ LogCapture().stream();
+ ElementArray foo;
+ return foo;
+}
+ElementManager::ElementManager() : array_(makeArray()) {}
diff --git a/gcc/tree-cfg.c b/gcc/tree-cfg.c
index 84e58e66628..78c0c6a4189 100644
--- a/gcc/tree-cfg.c
+++ b/gcc/tree-cfg.c
@@ -2944,35 +2944,6 @@ last_and_only_stmt (basic_block bb)
return NULL;
}
-/* Reinstall those PHI arguments queued in OLD_EDGE to NEW_EDGE. */
-
-static void
-reinstall_phi_args (edge new_edge, edge old_edge)
-{
- edge_var_map *vm;
- int i;
- gphi_iterator phis;
-
- vec<edge_var_map> *v = redirect_edge_var_map_vector (old_edge);
- if (!v)
- return;
-
- for (i = 0, phis = gsi_start_phis (new_edge->dest);
- v->iterate (i, &vm) && !gsi_end_p (phis);
- i++, gsi_next (&phis))
- {
- gphi *phi = phis.phi ();
- tree result = redirect_edge_var_map_result (vm);
- tree arg = redirect_edge_var_map_def (vm);
-
- gcc_assert (result == gimple_phi_result (phi));
-
- add_phi_arg (phi, arg, new_edge, redirect_edge_var_map_location (vm));
- }
-
- redirect_edge_var_map_clear (old_edge);
-}
-
/* Returns the basic block after which the new basic block created
by splitting edge EDGE_IN should be placed. Tries to keep the new block
near its "logical" location. This is of most help to humans looking
@@ -3012,11 +2983,24 @@ gimple_split_edge (edge edge_in)
new_bb = create_empty_bb (after_bb);
new_bb->count = edge_in->count ();
- e = redirect_edge_and_branch (edge_in, new_bb);
- gcc_assert (e == edge_in);
-
+ /* We want to avoid re-allocating PHIs when we first
+ add the fallthru edge from new_bb to dest but we also
+ want to avoid changing PHI argument order when
+ first redirecting edge_in away from dest. The former
+ avoids changing PHI argument order by adding them
+ last and then the redirection swapping it back into
+ place by means of unordered remove.
+ So hack around things by temporarily removing all PHIs
+ from the destination during the edge redirection and then
+ making sure the edges stay in order. */
+ gimple_seq saved_phis = phi_nodes (dest);
+ unsigned old_dest_idx = edge_in->dest_idx;
+ set_phi_nodes (dest, NULL);
new_edge = make_single_succ_edge (new_bb, dest, EDGE_FALLTHRU);
- reinstall_phi_args (new_edge, e);
+ e = redirect_edge_and_branch (edge_in, new_bb);
+ gcc_assert (e == edge_in && new_edge->dest_idx == old_dest_idx);
+ /* set_phi_nodes sets the BB of the PHI nodes, so do it manually here. */
+ dest->il.gimple.phi_nodes = saved_phis;
return new_bb;
}