+/**
+ * Compute the deepest common ancestor of block and dca.
+ */
+static ir_node *calc_dca(ir_node *dca, ir_node *block)
+{
+ assert(block);
+
+ /* we do not want to place nodes in dead blocks */
+ if (is_Block_dead(block))
+ return dca;
+
+ /* We found a first legal placement. */
+ if (!dca) return block;
+
+ /* Find a placement that is dominates both, dca and block. */
+ while (get_Block_dom_depth(block) > get_Block_dom_depth(dca))
+ block = get_Block_idom(block);
+
+ while (get_Block_dom_depth(dca) > get_Block_dom_depth(block)) {
+ dca = get_Block_idom(dca);
+ }
+
+ while (block != dca)
+ { block = get_Block_idom(block); dca = get_Block_idom(dca); }
+
+ return dca;
+}