X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fbe%2Fbepeephole.c;h=3194b4be9bd93325025a1654e5b351be67c544a5;hb=9003bb80f110a064291884dc408221d528686543;hp=d2377900044b8358da5b40122b1299fb5b120ba8;hpb=afaa73cdbc3679a791e1536a35fdd2971391cf0c;p=libfirm

diff --git a/ir/be/bepeephole.c b/ir/be/bepeephole.c
index d23779000..3194b4be9 100644
--- a/ir/be/bepeephole.c
+++ b/ir/be/bepeephole.c
@@ -261,6 +261,58 @@ static void	kill_barriers(ir_graph *irg) {
 	skip_barrier(start_blk, irg);
 }
 
+/*
+ * Tries to optimize a beIncSp node with it's previous IncSP node.
+ * Must be run from a be_peephole_opt() context.
+ */
+void be_peephole_IncSP_IncSP(ir_node *node)
+{
+	int      pred_offs;
+	int      curr_offs;
+	int      offs;
+	ir_node *pred = be_get_IncSP_pred(node);
+	ir_node *predpred;
+
+	if (!be_is_IncSP(pred))
+		return;
+
+	if (get_irn_n_edges(pred) > 1)
+		return;
+
+	pred_offs = be_get_IncSP_offset(pred);
+	curr_offs = be_get_IncSP_offset(node);
+
+	if (pred_offs == BE_STACK_FRAME_SIZE_EXPAND) {
+		if (curr_offs != BE_STACK_FRAME_SIZE_SHRINK) {
+			return;
+		}
+		offs = 0;
+	} else if (pred_offs == BE_STACK_FRAME_SIZE_SHRINK) {
+		if (curr_offs != BE_STACK_FRAME_SIZE_EXPAND) {
+			return;
+		}
+		offs = 0;
+	} else if (curr_offs == BE_STACK_FRAME_SIZE_EXPAND ||
+	           curr_offs == BE_STACK_FRAME_SIZE_SHRINK) {
+		return;
+	} else {
+		offs = curr_offs + pred_offs;
+	}
+
+	/* add pred offset to ours and remove pred IncSP */
+	be_set_IncSP_offset(node, offs);
+
+	predpred = be_get_IncSP_pred(pred);
+	be_peephole_before_exchange(pred, predpred);
+
+	/* rewire dependency edges */
+	edges_reroute_kind(pred, predpred, EDGE_KIND_DEP, current_ir_graph);
+	be_set_IncSP_pred(node, predpred);
+	sched_remove(pred);
+	be_kill_node(pred);
+
+	be_peephole_after_exchange(predpred);
+}
 
 void be_peephole_opt(be_irg_t *birg)
 {