struct be_chordal_env_t {
struct obstack *obst; /**< An obstack for temporary storage. */
be_ra_chordal_opts_t *opts; /**< A pointer to the chordal ra options. */
- be_irg_t *birg; /**< Back-end IRG session. */
ir_graph *irg; /**< The graph under examination. */
const arch_register_class_t *cls; /**< The current register class. */
pmap *border_heads; /**< Maps blocks to border heads. */