re PR middle-end/80775 (-O3 produces ice in group_case_labels_stmt)

[gcc.git] / gcc / tree-cfg.c

diff --git a/gcc/tree-cfg.c b/gcc/tree-cfg.c
index e046a13a5fe91abeafe0fd285b2fb122c683b353..ba19661b860c430108c946dca31f3b41f17c5c25 100644 (file)
--- a/gcc/tree-cfg.c
+++ b/gcc/tree-cfg.c
@@ -1661,7 +1661,7 @@ void
 group_case_labels_stmt (gswitch *stmt)
 {
   int old_size = gimple_switch_num_labels (stmt);
-  int i, j, new_size = old_size;
+  int i, j, base_index, new_size = old_size;
   basic_block default_bb = NULL;
 
   default_bb = label_to_block (CASE_LABEL (gimple_switch_default_label (stmt)));
@@ -1678,16 +1678,9 @@ group_case_labels_stmt (gswitch *stmt)
       gcc_assert (base_case);
       base_bb = label_to_block (CASE_LABEL (base_case));
 
-      /* Discard cases that have the same destination as the default case
-        or if their destination block is unreachable.  */
-      if (base_bb == default_bb
-         || (EDGE_COUNT (base_bb->succs) == 0
-             && gimple_seq_unreachable_p (bb_seq (base_bb))))
+      /* Discard cases that have the same destination as the default case.  */
+      if (base_bb == default_bb)
        {
-         edge e;
-         if (base_bb != default_bb
-             && (e = find_edge (gimple_bb (stmt), base_bb)) != NULL)
-           remove_edge_and_dominated_blocks (e);
          gimple_switch_set_label (stmt, i, NULL_TREE);
          i++;
          new_size--;
@@ -1697,7 +1690,7 @@ group_case_labels_stmt (gswitch *stmt)
       base_high = CASE_HIGH (base_case)
          ? CASE_HIGH (base_case)
          : CASE_LOW (base_case);
-      i++;
+      base_index = i++;
 
       /* Try to merge case labels.  Break out when we reach the end
         of the label vector or when we cannot merge the next case
@@ -1723,6 +1716,18 @@ group_case_labels_stmt (gswitch *stmt)
          else
            break;
        }
+
+      /* Discard cases that have an unreachable destination block.  */
+      if (EDGE_COUNT (base_bb->succs) == 0
+         && gimple_seq_unreachable_p (bb_seq (base_bb)))
+       {
+         edge base_edge = find_edge (gimple_bb (stmt), base_bb);
+         if (base_edge != NULL)
+           remove_edge_and_dominated_blocks (base_edge);
+         gimple_switch_set_label (stmt, base_index, NULL_TREE);
+         new_size--;
+         i++;
+       }
     }
 
   /* Compress the case labels in the label vector, and adjust the