+/**
+ * Environment for each of the chordal register allocator phases
+ */
+struct _be_chordal_env_t {
+ struct obstack obst; /**< An obstack for temporary storage. */
+ pmap *border_heads; /**< Maps blocks to border heads. */
+ ir_graph *irg; /**< The graph the reg alloc is running on. */
+
+#ifdef BUILD_GRAPH
+ set *nodes; /**< The interference graph nodes. */
+ set *edges; /**< The interference graph edges. */
+#endif
+
+ bitset_t *live; /**< A liveness bitset. */
+ bitset_t *colors; /**< The color mask. */
+ bitset_t *in_colors; /**< Colors used by live in values. */
+ int colors_n; /**< The number of colors. */
+ const arch_env_t *arch_env; /**< The arch interface environment. */
+ const arch_register_class_t *cls; /**< The current register class. */
+ void *data; /**< Some pointer, to which different
+ phases can attach data to. */
+};
+
+static INLINE struct list_head *
+_get_block_border_head(const be_chordal_env_t *inf, ir_node *bl)
+{
+ return pmap_get(inf->border_heads, bl);
+}
+
+#define get_block_border_head(info, bl) _get_block_border_head(info, bl)
+
+int nodes_interfere(const be_chordal_env_t *env, const ir_node *a, const ir_node *b);
+