refactored nodes interface, completed set/get attr methods

[libfirm] / ir / be / beconstrperm.c

diff --git a/ir/be/beconstrperm.c b/ir/be/beconstrperm.c
index 9522260..92311a2 100644 (file)
--- a/ir/be/beconstrperm.c
+++ b/ir/be/beconstrperm.c
@@ -21,23 +21,55 @@
 
 static void walker_insert_constr_perms(ir_node *bl, void *env) {
        ir_node *irn;
-       be_chordal_env_t *cenv = env;
-       const be_main_env_t *menv = cenv->main_env;
-       const arch_env_t *aenv = menv->arch_env;
+       int pos, max, cnt = 0;
        arch_register_req_t req;
-       int pos, max;
+       ir_graph *irg             = get_irn_irg(bl);
+       be_chordal_env_t *cenv    = env;
+       const be_main_env_t *menv = cenv->main_env;
+       const arch_env_t *aenv    = menv->arch_env;
 
        sched_foreach(bl, irn) {
+               ir_node *perm = NULL;
+
                /* check for a restriction of the result (-1) or one of the operands (0..n) */
                max = get_irn_arity(irn);
                for(pos=-1; pos<max; ++pos) {
+                       req.type = arch_register_req_type_none;
                        arch_get_register_req(aenv, &req, irn, pos);
+
                        /* if a restriction is found, insert a perm before the irn */
-                       if (req.type == arch_register_req_type_limited) {
-                               insert_Perm_after(menv, cenv->cls, cenv->dom_front, sched_prev(irn));
-                               /* TODO: Next line is overkill. Update_liveness would suffice. */
-                               be_liveness(get_irn_irg(bl));
-                               break;
+                       if (cenv->cls == arch_get_irn_reg_class(aenv, irn, pos) && req.type == arch_register_req_type_limited) {
+
+                               /*
+                                * If we inserted a perm,
+                                * we have to recompute liveness analysis since inserting
+                                * a Perm changes the liveness situation at the end
+                                * of the block.
+                                * (its needed by successive calls to insert_Perm_after)
+                                * Perhaps thinking about an online liveness analysis
+                                * would help.
+                                */
+                               if(!perm) {
+                                       perm = insert_Perm_after(menv, cenv->cls, cenv->dom_front, sched_prev(irn));
+                                       be_liveness(irg);
+                               }
+
+                               /*
+                                * Turn an input constraint into an output constraint:
+                                * The Proj of the Perm which corresponds to the input
+                                * constraint will have the input constraint of the node
+                                * as an output constraint
+                                */
+                               if(pos >= 0) {
+                                       ir_node *op = get_irn_n(irn, pos);
+
+                                       /*
+                                        * The operand must be a proj now, since a perm cut
+                                        * all live ranges.
+                                        */
+                                       assert(is_Proj(op));
+                                       be_set_Perm_out_req(perm, get_Proj_proj(op), &req);
+                               }
                        }
                }
        }