#include "irnode_t.h"
#include "ircons_t.h"
#include "array.h"
+#include "iredges.h"
#define get_dom_info(bl) (&(bl)->attr.block.dom)
return 0;
}
+/* Returns the smallest common dominator block of two nodes. */
+ir_node *node_smallest_common_dominator(ir_node *a, ir_node *b) {
+ ir_node *bl_a = is_Block(a) ? a : get_nodes_block(a);
+ ir_node *bl_b = is_Block(b) ? b : get_nodes_block(b);
+ ir_node *dom_bl = NULL;
+
+ /* Check if block of a dominates block of b */
+ if (block_dominates(bl_a, bl_b))
+ dom_bl = bl_a;
+ /* Check if block of b dominates block of a */
+ else if (block_dominates(bl_b, bl_a))
+ dom_bl = bl_b;
+ else {
+ /* walk up dominator tree and search for first block dominating a and b */
+ while (! dom_bl) {
+ bl_a = get_Block_idom(bl_a);
+
+ assert(! is_Bad(bl_a) && "block is dead?");
+
+ if (block_dominates(bl_a, bl_b))
+ dom_bl = bl_a;
+ }
+ }
+
+ return dom_bl;
+}
+
+/* Returns the smallest common dominator block of all users of a node. */
+ir_node *node_users_smallest_common_dominator(ir_node *irn, int handle_phi) {
+ int n, j, i = 0, success;
+ ir_node **user_blocks, *dom_bl;
+ const ir_edge_t *edge;
+
+ assert(! is_Block(irn) && "WRONG USAGE of node_users_smallest_common_dominator");
+ assert(edges_activated(get_irn_irg(irn)) && "need edges activated");
+
+ n = get_irn_n_edges(irn);
+
+ /* get array to hold all block of the node users */
+ NEW_ARR_A(ir_node *, user_blocks, n);
+ foreach_out_edge(irn, edge) {
+ ir_node *src = get_edge_src_irn(edge);
+
+ if (is_Phi(src) && handle_phi) {
+ /* get the corresponding cfg predecessor block if phi handling requested */
+ j = get_irn_pred_pos(src, irn);
+ assert(j >= 0 && "kaputt");
+ user_blocks[i++] = get_nodes_block(get_Block_cfgpred_block(get_nodes_block(src), j));
+ }
+ else
+ user_blocks[i++] = is_Block(src) ? src : get_nodes_block(src);
+ }
+
+ /* in case of only one user: return the block of the user */
+ if (n == 1)
+ return user_blocks[0];
+
+ i = 0;
+ /* search the smallest block dominating all user blocks */
+ do {
+ dom_bl = node_smallest_common_dominator(user_blocks[i], user_blocks[i + 1]);
+ success = 1;
+
+ /* check if this block dominates all remaining blocks as well */
+ for (j = i + 2; j < n; j++) {
+ if (! block_dominates(dom_bl, user_blocks[j]))
+ success = 0;
+ }
+
+ if (success)
+ break;
+
+ /* inherit the dominator block of the first (i + 1) users */
+ user_blocks[++i] = dom_bl;
+ } while (i < n - 1);
+
+ assert(success && "no block found dominating all users");
+
+ return dom_bl;
+}
+
+
/* Get the first node in the list of nodes dominated by a given block. */
ir_node *get_Block_dominated_first(const ir_node *bl)
{
*/
int block_dominates(const ir_node *a, const ir_node *b);
+/**
+ * Returns the smallest common dominator block of two nodes.
+ * @param a A node.
+ * @param b Another node.
+ * @return The first block dominating @p a and @p b
+ */
+ir_node *node_smallest_common_dominator(ir_node *a, ir_node *b);
+
+/**
+ * Returns the smallest common dominator block of all users of a node
+ * BEWARE: @p irn must not be a block
+ * If on or more users are Phi nodes, one can request special handling
+ * with @p handle_phi = 1. In this case the cfg predecessor block
+ * corresponding to the position of the irn in the argument list of the
+ * Phi is determined and treated as user.
+ *
+ * @param irn A node.
+ * @param handle_phi 1 if Phis should be handled different
+ * @return The first block dominating all users of @irn
+ */
+ir_node *node_users_smallest_common_dominator(ir_node *irn, int handle_phi);
+
/**
* Check, if a block post dominates another block.
* @param a The first block.