diff options
| -rw-r--r-- | gcc/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/tree-ssa-structalias.c | 47 |
2 files changed, 46 insertions, 7 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index aa966f93906..60394c74e49 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2013-02-01 Richard Biener <rguenther@suse.de> + + PR tree-optimization/56113 + * tree-ssa-structalias.c (label_visit): Reduce work for + single-predecessor nodes. + 2013-02-01 Eric Botcazou <ebotcazou@adacore.com> * fold-const.c (make_range_step) <TRUTH_NOT_EXPR>: Bail out if the diff --git a/gcc/tree-ssa-structalias.c b/gcc/tree-ssa-structalias.c index 1bbe1cc5ae0..bee27b1f1c5 100644 --- a/gcc/tree-ssa-structalias.c +++ b/gcc/tree-ssa-structalias.c @@ -2107,14 +2107,13 @@ condense_visit (constraint_graph_t graph, struct scc_info *si, unsigned int n) static void label_visit (constraint_graph_t graph, struct scc_info *si, unsigned int n) { - unsigned int i; + unsigned int i, first_pred; bitmap_iterator bi; - bitmap_set_bit (si->visited, n); - if (!graph->points_to[n]) - graph->points_to[n] = BITMAP_ALLOC (&predbitmap_obstack); + bitmap_set_bit (si->visited, n); /* Label and union our incoming edges's points to sets. */ + first_pred = -1U; EXECUTE_IF_IN_NONNULL_BITMAP (graph->preds[n], 0, i, bi) { unsigned int w = si->node_mapping[i]; @@ -2126,11 +2125,45 @@ label_visit (constraint_graph_t graph, struct scc_info *si, unsigned int n) continue; if (graph->points_to[w]) - bitmap_ior_into(graph->points_to[n], graph->points_to[w]); + { + if (first_pred == -1U) + first_pred = w; + else if (!graph->points_to[n]) + { + graph->points_to[n] = BITMAP_ALLOC (&predbitmap_obstack); + bitmap_ior (graph->points_to[n], + graph->points_to[first_pred], graph->points_to[w]); + } + else + bitmap_ior_into(graph->points_to[n], graph->points_to[w]); + } } - /* Indirect nodes get fresh variables. */ + + /* Indirect nodes get fresh variables and a new pointer equiv class. */ if (!bitmap_bit_p (graph->direct_nodes, n)) - bitmap_set_bit (graph->points_to[n], FIRST_REF_NODE + n); + { + if (!graph->points_to[n]) + { + graph->points_to[n] = BITMAP_ALLOC (&predbitmap_obstack); + if (first_pred != -1U) + bitmap_copy (graph->points_to[n], graph->points_to[first_pred]); + } + bitmap_set_bit (graph->points_to[n], FIRST_REF_NODE + n); + graph->pointer_label[n] = pointer_equiv_class++; + return; + } + + /* If there was only a single non-empty predecessor the pointer equiv + class is the same. */ + if (!graph->points_to[n]) + { + if (first_pred != -1U) + { + graph->pointer_label[n] = graph->pointer_label[first_pred]; + graph->points_to[n] = graph->points_to[first_pred]; + } + return; + } if (!bitmap_empty_p (graph->points_to[n])) { |