We can only optimize one CopyB for each return value.

This fixes opt/fehler202.c.

diff --git a/ir/lower/lower_calls.c b/ir/lower/lower_calls.c
index 11ccc25..082822c 100644 (file)
--- a/ir/lower/lower_calls.c
+++ b/ir/lower/lower_calls.c
@@ -535,7 +535,7 @@ static void add_hidden_param(ir_graph *irg, size_t n_com, ir_node **ins,
                              cl_entry *entry, wlk_env *env,
                              ir_type *ctp)
 {
-       ir_node *p, *n, *mem, *blk;
+       ir_node *p, *n;
        size_t n_args;
 
        n_args = 0;
@@ -544,21 +544,25 @@ static void add_hidden_param(ir_graph *irg, size_t n_com, ir_node **ins,
                size_t   idx = get_Proj_proj(src);
                n = (ir_node*)get_irn_link(p);
 
-               ins[idx] = get_CopyB_dst(p);
-               blk      = get_nodes_block(p);
-
-               /* use the memory output of the call and not the input of the CopyB
-                * otherwise stuff breaks if the call was mtp_property_const, because
-                * then the copyb skips the call. But after lowering the call is not
-                * const anymore, and its memory has to be used */
-               mem = new_r_Proj(entry->call, mode_M, pn_Call_M);
-
-               /* get rid of the CopyB */
-               turn_into_tuple(p, pn_CopyB_max+1);
-               set_Tuple_pred(p, pn_CopyB_M,         mem);
-               set_Tuple_pred(p, pn_CopyB_X_regular, new_r_Jmp(blk));
-               set_Tuple_pred(p, pn_CopyB_X_except,  new_r_Bad(irg, mode_X));
-               ++n_args;
+               /* consider only the first CopyB */
+               if (ins[idx] == NULL) {
+                       ir_node *block = get_nodes_block(p);
+
+                       /* use the memory output of the call and not the input of the CopyB
+                        * otherwise stuff breaks if the call was mtp_property_const, because
+                        * then the copyb skips the call. But after lowering the call is not
+                        * const anymore, and its memory has to be used */
+                       ir_node *mem = new_r_Proj(entry->call, mode_M, pn_Call_M);
+
+                       ins[idx] = get_CopyB_dst(p);
+
+                       /* get rid of the CopyB */
+                       turn_into_tuple(p, pn_CopyB_max+1);
+                       set_Tuple_pred(p, pn_CopyB_M,         mem);
+                       set_Tuple_pred(p, pn_CopyB_X_regular, new_r_Jmp(block));
+                       set_Tuple_pred(p, pn_CopyB_X_except,  new_r_Bad(irg, mode_X));
+                       ++n_args;
+               }
        }
 
        /* now create dummy entities for function with ignored return value */
@@ -734,7 +738,8 @@ static void transform_irg(compound_call_lowering_flags flags, ir_graph *irg)
        env.changed        = false;
 
        /* scan the code, fix argument numbers and collect calls. */
-       irg_walk_graph(irg, firm_clear_link, fix_args_and_collect_calls, &env);
+       irg_walk_graph(irg, firm_clear_link, NULL, &env);
+       irg_walk_graph(irg, fix_args_and_collect_calls, NULL, &env);
 
        if (n_param_com > 0 && !(flags & LF_DONT_LOWER_ARGUMENTS))
                remove_compound_param_entities(irg);