remove arch_irn_class_is macro as it hides usages of arch_irn_class_XXX from grep...
[libfirm] / ir / be / bepeephole.c
index e5f9cc7..5d3065b 100644 (file)
@@ -256,16 +256,24 @@ static void kill_node_and_preds(ir_node *node)
 /**
  * Walk through the block schedule and skip all barrier nodes.
  */
-static void skip_barrier(ir_node *ret_blk, ir_graph *irg)
+static void skip_barrier(ir_node *block, ir_graph *irg)
 {
        ir_node *irn;
 
-       sched_foreach_reverse(ret_blk, irn) {
+       sched_foreach_reverse(block, irn) {
+               int       arity;
+               unsigned *used;
+               unsigned  n_used;
                const ir_edge_t *edge, *next;
 
                if (!be_is_Barrier(irn))
                        continue;
 
+               /* track which outputs are actually used, as we have to create
+                * keep nodes for unused outputs */
+               arity = get_irn_arity(irn);
+               rbitset_alloca(used, arity);
+
                foreach_out_edge_safe(irn, edge, next) {
                        ir_node *proj = get_edge_src_irn(edge);
                        int      pn;
@@ -277,10 +285,33 @@ static void skip_barrier(ir_node *ret_blk, ir_graph *irg)
                        pn   = (int) get_Proj_proj(proj);
                        pred = get_irn_n(irn, pn);
 
+                       rbitset_set(used, pn);
+
                        edges_reroute_kind(proj, pred, EDGE_KIND_NORMAL, irg);
                        edges_reroute_kind(proj, pred, EDGE_KIND_DEP, irg);
                }
 
+               /* the barrier also had the effect of a Keep for unused inputs.
+                * we now have to create an explicit Keep for them */
+               n_used = rbitset_popcount(used, arity);
+               if (n_used < (unsigned) arity) {
+                       int       n_in = arity - (int) n_used;
+                       ir_node **in   = ALLOCAN(ir_node*, n_in);
+                       int       i    = 0;
+                       int       n    = 0;
+                       ir_node  *keep;
+
+                       for (i = 0; i < arity; ++i) {
+                               if (rbitset_is_set(used, i))
+                                       continue;
+                               assert(n < n_in);
+                               in[n++] = get_irn_n(irn, i);
+                       }
+                       keep = be_new_Barrier(get_nodes_block(irn), n_in, in);
+                       keep_alive(keep);
+                       sched_add_before(irn, keep);
+               }
+
                kill_node_and_preds(irn);
                break;
        }
@@ -292,7 +323,7 @@ static void skip_barrier(ir_node *ret_blk, ir_graph *irg)
 static void    kill_barriers(ir_graph *irg)
 {
        ir_node *end_blk = get_irg_end_block(irg);
-       ir_node *start_blk;
+       ir_node *start_blk = get_irg_start_block(irg);
        int i;
 
        /* skip the barrier on all return blocks */
@@ -300,6 +331,9 @@ static void kill_barriers(ir_graph *irg)
                ir_node *be_ret = get_Block_cfgpred(end_blk, i);
                ir_node *ret_blk = get_nodes_block(be_ret);
 
+               if (ret_blk == start_blk)
+                       continue;
+
                skip_barrier(ret_blk, irg);
        }