It does not make any sense to remove AM, which loads a non-GP value to fix register...

[libfirm] / ir / opt / combo.c

diff --git a/ir/opt/combo.c b/ir/opt/combo.c
index 7181600..67fcd41 100644 (file)
--- a/ir/opt/combo.c
+++ b/ir/opt/combo.c
@@ -3023,6 +3023,27 @@ static void apply_cf(ir_node *block, void *ctx) {
        }
 }  /* apply_cf */
 
+/**
+ * Exchange a node by its leader.
+ * Beware: in rare cases the mode might be wrong here, for instance
+ * AddP(x, NULL) is a follower of x, but with different mode.
+ * Fix it here.
+ */
+static void exchange_leader(ir_node *irn, ir_node *leader) {
+       ir_mode *mode = get_irn_mode(irn);
+       if (mode != get_irn_mode(leader)) {
+               /* The conv is a no-op, so we are fre to place in
+                * either in the block of the leader OR in irn's block.
+                * Propably placing it into leaders block might reduce
+                * the number of Conv due to CSE. */
+               ir_node  *block = get_nodes_block(leader);
+               dbg_info *dbg   = get_irn_dbg_info(irn);
+
+               leader = new_rd_Conv(dbg, current_ir_graph, block, leader, mode);
+       }
+       exchange(irn, leader);
+}
+
 /**
  * Post-Walker, apply the analysis results;
  */
@@ -3095,7 +3116,7 @@ static void apply_result(ir_node *irn, void *ctx) {
                                        node->node = c;
                                        DB((dbg, LEVEL_1, "%+F is replaced by %+F\n", irn, c));
                                        DBG_OPT_COMBO(irn, c, FS_OPT_COMBO_CONST);
-                                       exchange(irn, c);
+                                       exchange_leader(irn, c);
                                        env->modified = 1;
                                }
                        } else if (is_entity(node->type.sym.entity_p)) {
@@ -3107,7 +3128,7 @@ static void apply_result(ir_node *irn, void *ctx) {
 
                                        DB((dbg, LEVEL_1, "%+F is replaced by %+F\n", irn, symc));
                                        DBG_OPT_COMBO(irn, symc, FS_OPT_COMBO_CONST);
-                                       exchange(irn, symc);
+                                       exchange_leader(irn, symc);
                                        env->modified = 1;
                                }
                        } else if (is_Confirm(irn)) {
@@ -3121,7 +3142,7 @@ static void apply_result(ir_node *irn, void *ctx) {
                                                DBG_OPT_COMBO(irn, leader, FS_OPT_COMBO_FOLLOWER);
                                        else
                                                DBG_OPT_COMBO(irn, leader, FS_OPT_COMBO_CONGRUENT);
-                                       exchange(irn, leader);
+                                       exchange_leader(irn, leader);
                                        env->modified = 1;
                                }
                        }