/**
- * Calls the backend code generator functions to lower Spill and
- * Reload nodes into Store and Load. The backend is fully responsible
- * for creating the new nodes and setting their input correct.
- * Note: The caller of this has to make sure that irn is a Spill
- * or Reload!
+ * Checks if node has a should_be_different constraint in output
+ * and adds a Keep then to assure the constraint.
+ */
+static void assure_different_constraint(ir_node *irn, be_irg_t *birg) {
+ const arch_env_t *arch_env = birg->main_env->arch_env;
+ const arch_register_req_t *req;
+ arch_register_req_t req_temp;
+ ir_node *in[2], *keep;
+ firm_dbg_module_t *mod = firm_dbg_register("firm.be.lower");
+
+ req = arch_get_register_req(arch_env, &req_temp, irn, -1);
+
+ if (req && arch_register_req_is(req, should_be_different)) {
+ /* We found a should_be_different constraint. */
+ assert(req->other_different && "missing irn for constraint");
+
+ in[0] = irn;
+ in[1] = req->other_different;
+
+ keep = be_new_Keep(req->cls, birg->irg, get_nodes_block(irn), 2, in);
+ DBG((mod, LEVEL_1, "created %+F for %+F to assure should_be_different\n", keep, irn));
+ }
+}
+
+
+
+/**
+ * Calls the functions to assure register constraints.
*
- * @param irn The Spill/Reload node
+ * @param irn The node to be checked for lowering
* @param walk_env The walker environment
*/
-static void lower_spill_reload(ir_node *irn, void *walk_env) {
- lower_env_t *env = walk_env;
- arch_code_generator_t *cg = env->chord_env->birg->cg;
- const arch_env_t *aenv = env->chord_env->birg->main_env->arch_env;
- ir_node *res = NULL;
- ir_node *sched_point;
-
- if (be_is_Spill(irn) && cg->impl->lower_spill) {
- res = cg->impl->lower_spill(cg, irn);
- }
- else if (be_is_Reload(irn) && cg->impl->lower_reload) {
- res = cg->impl->lower_reload(cg, irn);
- if (res && res != irn) {
- /* copy the result register from the reload to the load */
- arch_set_irn_register(aenv, res, arch_get_irn_register(aenv, irn));
- }
- }
+static void assure_constraints_walker(ir_node *irn, void *walk_env) {
+ if (is_Block(irn))
+ return;
- if (res && res != irn) {
- sched_point = sched_prev(irn);
- sched_remove(irn);
- exchange(irn, res);
- sched_add_after(sched_point, res);
- }
- else {
- DBG((env->dbg_module, LEVEL_1, "node %+F not lowered\n", irn));
- }
+ if (mode_is_datab(get_irn_mode(irn)))
+ assure_different_constraint(irn, walk_env);
return;
}
+/**
+ * Walks over all nodes to assure register constraints.
+ *
+ * @param birg The birg structure containing the irg
+ */
+void assure_constraints(be_irg_t *birg) {
+ irg_walk_blkwise_graph(birg->irg, NULL, assure_constraints_walker, birg);
+}
+
+
+
/**
* Calls the corresponding lowering function for the node.
*
if (is_Perm(arch_env, irn)) {
lower_perm_node(irn, walk_env);
}
- else if (be_is_Spill(irn) || be_is_Reload(irn)) {
- lower_spill_reload(irn, walk_env);
- }
}
return;
/**
* Walks over all blocks in an irg and performs lowering need to be
- * done after register allocation (e.g. perm and spill/reload lowering).
+ * done after register allocation (e.g. perm lowering).
*
* @param chord_env The chordal environment containing the irg
* @param do_copy 1 == resolve cycles with a free reg if available