remove barrier from schedule before peephole optimization

[r19813]

diff --git a/ir/be/bepeephole.c b/ir/be/bepeephole.c
index 1f73806..48e32bf 100644 (file)
--- a/ir/be/bepeephole.c
+++ b/ir/be/bepeephole.c
@@ -37,6 +37,7 @@
 #include "beirg_t.h"
 #include "belive_t.h"
 #include "bearch_t.h"
+#include "benode_t.h"
 #include "besched_t.h"
 #include "bemodule.h"
 
@@ -213,12 +214,82 @@ static void process_block(ir_node *block, void *data)
        }
 }
 
+/**
+ * Walk through the block schedule and skip all barrier nodes.
+ */
+static void skip_barrier(ir_node *ret_blk) {
+       ir_node *irn;
+
+       sched_foreach_reverse(ret_blk, irn) {
+               int i;
+
+               for (i = get_irn_arity(irn) - 1; i >= 0; --i) {
+                       ir_node *proj = get_irn_n(irn, i);
+
+                       if (is_Proj(proj)) {
+                               ir_node *barrier = get_Proj_pred(proj);
+
+                               if (be_is_Barrier(barrier)) {
+                                       int pn        = (int)get_Proj_proj(proj);
+                                       ir_node *pred = get_irn_n(barrier, pn);
+
+                                       set_irn_n(irn, i, pred);
+                                       if (sched_is_scheduled(barrier))
+                                               sched_remove(barrier);
+                               }
+                       }
+               }
+               for (i = get_irn_deps(irn) - 1; i >= 0; --i) {
+                       ir_node *proj = get_irn_dep(irn, i);
+
+                       if (is_Proj(proj)) {
+                               ir_node *barrier = get_Proj_pred(proj);
+
+                               if (be_is_Barrier(barrier)) {
+                                       int pn        = (int)get_Proj_proj(proj);
+                                       ir_node *pred = get_irn_n(barrier, pn);
+
+                                       set_irn_dep(irn, i, pred);
+                                       if (sched_is_scheduled(barrier))
+                                               sched_remove(barrier);
+                               }
+                       }
+               }
+       }
+}
+
+/**
+ * Kill the Barrier nodes for better peephole optimization.
+ */
+static void    kill_barriers(ir_graph *irg) {
+       ir_node *end_blk = get_irg_end_block(irg);
+       ir_node *start_blk;
+       int i;
+
+       /* skip the barrier on all return blocks */
+       for (i = get_Block_n_cfgpreds(end_blk) - 1; i >= 0; --i) {
+               ir_node *be_ret = get_Block_cfgpred(end_blk, i);
+               ir_node *ret_blk = get_nodes_block(be_ret);
+
+               skip_barrier(ret_blk);
+       }
+
+       /* skip the barrier on the start block */
+       start_blk = get_irg_start_block(irg);
+       skip_barrier(start_blk);
+}
+
+
 void be_peephole_opt(be_irg_t *birg)
 {
        ir_graph   *irg = be_get_birg_irg(birg);
        unsigned n_classes;
        unsigned i;
 
+       /* barrier nodes are used for register allocations. They hinders
+        * peephole optimizations, so remove them here. */
+       kill_barriers(irg);
+
        /* we sometimes find BadE nodes in float apps like optest_float.c or
         * kahansum.c for example... */
        be_liveness_invalidate(birg->lv);