+/* Move debug stmts from the forwarder block SRC to DEST. */
+
+static void
+move_debug_stmts_from_forwarder (basic_block src, basic_block dest)
+{
+ if (!MAY_HAVE_DEBUG_STMTS)
+ return;
+
+ bool can_move_debug_stmts = single_pred_p (dest);
+ gimple_stmt_iterator gsi_to = gsi_after_labels (dest);
+ for (gimple_stmt_iterator gsi = gsi_after_labels (src); !gsi_end_p (gsi);)
+ {
+ gimple *debug = gsi_stmt (gsi);
+ gcc_assert (is_gimple_debug (debug));
+ /* Move debug binds anyway, but not anything else like begin-stmt
+ markers unless they are always valid at the destination. */
+ if (can_move_debug_stmts
+ || gimple_debug_bind_p (debug))
+ {
+ gsi_move_before (&gsi, &gsi_to);
+ /* Reset debug-binds that are not always valid at the destination.
+ Simply dropping them can cause earlier values to become live,
+ generating wrong debug information.
+ ??? There are several things we could improve here. For
+ one we might be able to move stmts to the predecessor.
+ For anther, if the debug stmt is immediately followed by a
+ (debug) definition in the destination (on a post-dominated path?)
+ we can elide it without any bad effects. */
+ if (!can_move_debug_stmts)
+ {
+ gimple_debug_bind_reset_value (debug);
+ update_stmt (debug);
+ }
+ }
+ else
+ gsi_next (&gsi);
+ }
+}
+