-/**
- * Generates constraints which interrelate x with y variables.
- * x1 and x2 have the different colors ==> y_12 = 1
- */
-static void pi_add_constr_E(problem_instance_t *pi) {
- unit_t *curr;
- bitset_t *root_regs, *arg_regs, *work_regs;
- int cst_counter = 0;
- unsigned nregs = pi->co->chordal_env->cls->n_regs;
- root_regs = bitset_alloca(nregs);
- arg_regs = bitset_alloca(nregs);
- work_regs = bitset_alloca(nregs);
-
- DBG((dbg, LEVEL_2, "Add E constraints...\n"));
- /* for all roots of optimization units */
- list_for_each_entry(unit_t, curr, &pi->co->units, units) {
- ir_node *root, *arg;
- int rootnr, argnr, color;
- int y_idx, i;
- char buf[32];
-
- root = curr->nodes[0];
- rootnr = get_irn_graph_nr(root);
- bitset_clear_all(root_regs);
- arch_get_allocatable_regs(get_arch_env(pi->co), root, -1, root_regs);
-
- /* for all arguments of root */
- for (i = 1; i < curr->node_count; ++i) {
- arg = curr->nodes[i];
- argnr = get_irn_graph_nr(arg);
- bitset_clear_all(arg_regs);
- arch_get_allocatable_regs(get_arch_env(pi->co), arg, -1, arg_regs);
-
- /* Introduce new variable and set factor in objective function */
- mangle_var2(buf, 'y', rootnr, argnr);
- y_idx = lpp_add_var(pi->curr_lp, buf, lpp_binary, curr->costs[i]);
-
- /* set starting value */
- lpp_set_start_value(pi->curr_lp, y_idx, (get_irn_col(pi->co, root) != get_irn_col(pi->co, arg)));
-
- /* For all colors root and arg have in common, add 2 constraints to E */
- bitset_copy(work_regs, root_regs);
- bitset_and(work_regs, arg_regs);
- bitset_foreach(work_regs, color) {
- int root_idx, arg_idx, cst_idx;
- mangle_var2(buf, 'x', rootnr, color);
- root_idx = lpp_get_var_idx(pi->curr_lp, buf);
- mangle_var2(buf, 'x', argnr, color);
- arg_idx = lpp_get_var_idx(pi->curr_lp, buf);
-
- /* add root-arg-y <= 0 */
- mangle_cst(buf, 'E', cst_counter++);
- cst_idx = lpp_add_cst(pi->curr_lp, buf, lpp_less, 0);
- lpp_set_factor_fast(pi->curr_lp, cst_idx, root_idx, 1);
- lpp_set_factor_fast(pi->curr_lp, cst_idx, arg_idx, -1);
- lpp_set_factor_fast(pi->curr_lp, cst_idx, y_idx, -1);
-
- /* add arg-root-y <= 0 */
- mangle_cst(buf, 'E', cst_counter++);
- cst_idx = lpp_add_cst(pi->curr_lp, buf, lpp_less, 0);
- lpp_set_factor_fast(pi->curr_lp, cst_idx, root_idx, -1);
- lpp_set_factor_fast(pi->curr_lp, cst_idx, arg_idx, 1);
- lpp_set_factor_fast(pi->curr_lp, cst_idx, y_idx, -1);
- }
- /* For all colors root and arg have "disjunct", add 1 constraints to E.
- * If root gets a color the arg is not possible to get then they will
- * definetly get different colors. So y has to be 1.
- * Vice versa for arg.
- */
- bitset_copy(work_regs, root_regs);
- bitset_xor(work_regs, arg_regs);
- bitset_foreach(work_regs, color) {
- int root_idx, arg_idx, cst_idx;
- mangle_var2(buf, 'x', rootnr, color);
- root_idx = lpp_get_var_idx(pi->curr_lp, buf);
- mangle_var2(buf, 'x', argnr, color);
- arg_idx = lpp_get_var_idx(pi->curr_lp, buf);
-
- mangle_cst(buf, 'E', cst_counter++);
- cst_idx = lpp_add_cst(pi->curr_lp, buf, lpp_less, 0);
- if (bitset_is_set(root_regs, color)) {
- /* add root-y <= 0 */
- lpp_set_factor_fast(pi->curr_lp, cst_idx, root_idx, 1);
- lpp_set_factor_fast(pi->curr_lp, cst_idx, y_idx, -1);
- } else {
- assert(bitset_is_set(arg_regs, color) && "bitset_xor is buggy");
- /* add arg-y <= 0 */
- lpp_set_factor_fast(pi->curr_lp, cst_idx, arg_idx, 1);
- lpp_set_factor_fast(pi->curr_lp, cst_idx, y_idx, -1);
- }
- }
- }
- }
-}