X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fbe%2Fbeconstrperm.c;h=92311a2657e9b104520023c3dd818b663abdc24c;hb=ba873a5483697d4ff93e3980d7b6a1b5cbc491b5;hp=f493ba7ae9ed04d44a66d301be1d0b6709e51e6d;hpb=f40f11d2d70c73b4daaba5130a9587233c25c1d3;p=libfirm

diff --git a/ir/be/beconstrperm.c b/ir/be/beconstrperm.c
index f493ba7ae..92311a265 100644
--- 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 (cenv->cls == arch_get_irn_reg_class(aenv, irn, pos) && 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 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);
+				}
 			}
 		}
 	}