-/* State of basic block as seen by find_many_sub_basic_blocks. */
-enum state {BLOCK_NEW = 0, BLOCK_ORIGINAL, BLOCK_TO_SPLIT};
+/* States of basic block as seen by find_many_sub_basic_blocks. */
+enum state {
+ /* Basic blocks created via split_block belong to this state.
+ make_edges will examine these basic blocks to see if we need to
+ create edges going out of them. */
+ BLOCK_NEW = 0,
+
+ /* Basic blocks that do not need examining belong to this state.
+ These blocks will be left intact. In particular, make_edges will
+ not create edges going out of these basic blocks. */
+ BLOCK_ORIGINAL,
+
+ /* Basic blocks that may need splitting (due to a label appearing in
+ the middle, etc) belong to this state. After splitting them,
+ make_edges will create edges going out of them as needed. */
+ BLOCK_TO_SPLIT
+};