small bugfix/cleanup of phi preference propagation

[r26516]

diff --git a/ir/be/benewalloc.c b/ir/be/benewalloc.c
index 3fa1716..c19b1ef 100644 (file)
--- a/ir/be/benewalloc.c
+++ b/ir/be/benewalloc.c
@@ -86,7 +86,7 @@
 #define AFF_SHOULD_BE_SAME             0.5f
 #define AFF_PHI                        1.0f
 #define SPLIT_DELTA                    1.0f
-#define MAX_OPTIMISTIC_SPLIT_RECURSION 2
+#define MAX_OPTIMISTIC_SPLIT_RECURSION 0
 
 DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
 
@@ -1470,9 +1470,9 @@ static void adapt_phi_prefs(ir_node *phi)
  */
 static void propagate_phi_register(ir_node *phi, unsigned assigned_r)
 {
-       int                    i;
-       ir_node               *block = get_nodes_block(phi);
-       int                    arity = get_irn_arity(phi);
+       int      i;
+       ir_node *block = get_nodes_block(phi);
+       int      arity = get_irn_arity(phi);
 
        for (i = 0; i < arity; ++i) {
                ir_node           *op         = get_Phi_pred(phi, i);
@@ -1487,12 +1487,11 @@ static void propagate_phi_register(ir_node *phi, unsigned assigned_r)
 
                /* promote the prefered register */
                for (r = 0; r < n_regs; ++r) {
-                       if (r == assigned_r) {
-                               info->prefs[r] = AFF_PHI * weight;
-                       } else {
-                               info->prefs[r] -= AFF_PHI * weight;
+                       if (info->prefs[r] > -weight) {
+                               info->prefs[r] = -weight;
                        }
                }
+               info->prefs[assigned_r] = weight;
 
                if (is_Phi(op))
                        propagate_phi_register(op, assigned_r);