diff options
| -rw-r--r-- | gcc/tree-cfg.c | 50 |
1 files changed, 17 insertions, 33 deletions
diff --git a/gcc/tree-cfg.c b/gcc/tree-cfg.c index 3d825c2..5139f11 100644 --- a/gcc/tree-cfg.c +++ b/gcc/tree-cfg.c @@ -2888,35 +2888,6 @@ 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 @@ -2956,11 +2927,24 @@ 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; } |