diff --git a/src/mesa/drivers/dri/i965/brw_cfg.cpp b/src/mesa/drivers/dri/i965/brw_cfg.cpp
index d806b83c0db..9cd8b9fcdf3 100644
--- a/src/mesa/drivers/dri/i965/brw_cfg.cpp
+++ b/src/mesa/drivers/dri/i965/brw_cfg.cpp
@@ -71,6 +71,30 @@ bblock_t::add_successor(void *mem_ctx, bblock_t *successor)
    children.push_tail(::link(mem_ctx, successor));
 }
 
+bool
+bblock_t::is_predecessor_of(const bblock_t *block) const
+{
+   foreach_list_typed_safe (bblock_link, parent, link, &block->parents) {
+      if (parent->block == this) {
+         return true;
+      }
+   }
+
+   return false;
+}
+
+bool
+bblock_t::is_successor_of(const bblock_t *block) const
+{
+   foreach_list_typed_safe (bblock_link, child, link, &block->children) {
+      if (child->block == this) {
+         return true;
+      }
+   }
+
+   return false;
+}
+
 void
 bblock_t::dump(backend_visitor *v)
 {
diff --git a/src/mesa/drivers/dri/i965/brw_cfg.h b/src/mesa/drivers/dri/i965/brw_cfg.h
index 29e31e77efb..a6888704e28 100644
--- a/src/mesa/drivers/dri/i965/brw_cfg.h
+++ b/src/mesa/drivers/dri/i965/brw_cfg.h
@@ -58,6 +58,8 @@ struct bblock_t {
    bblock_t();
 
    void add_successor(void *mem_ctx, bblock_t *successor);
+   bool is_predecessor_of(const bblock_t *block) const;
+   bool is_successor_of(const bblock_t *block) const;
    void dump(backend_visitor *v);
 #endif