+# include "irgopt_t.h"
+# include "irnode_t.h"
+# include "irouts.h"
+# include "trouts.h"
+# include "hashptr.h"
+# include "pset.h"
+# include "strength_red.h"
+
+/* We will unroll maximal 4-times. */
+#define MAX_UNROLL 4
+
+/* We will know if the head of the loop to be copy.
+ * Default "0" don't copy.*/
+static int copy_loop_head;
+
+typedef struct {
+ ir_node *irn ; /* Node of the loop to be unrolling*/
+ ir_node *copy[MAX_UNROLL] ; /* The copy of the node */
+} copies_t;
+
+/**
+ * Compare two elements of the copies_t set
+ */
+static int set_cmp(const void *elt, const void *key, size_t size)
+{
+ const copies_t *c1 = elt;
+ const copies_t *c2 = key;
+
+ return c1->irn != c2->irn;
+}
+
+static INLINE int * new_backedge_arr(struct obstack *obst, int size)
+{
+ int *res = NEW_ARR_D (int, obst, size);
+ memset(res, 0, sizeof(int) * size);
+ return res;
+}
+
+static INLINE void new_backedge_info(ir_node *n) {
+ switch(get_irn_opcode(n)) {
+ case iro_Block:
+ n->attr.block.cg_backedge = NULL;
+ n->attr.block.backedge = new_backedge_arr(current_ir_graph->obst, get_irn_arity(n));
+ break;
+ case iro_Phi:
+ n->attr.phi_backedge = new_backedge_arr(current_ir_graph->obst, get_irn_arity(n));
+ break;
+ case iro_Filter:
+ n->attr.filter.backedge = new_backedge_arr(current_ir_graph->obst, get_irn_arity(n));
+ break;
+ default: ;
+ }
+}
+
+/**
+ * Remember the new node in the old node by using a field all nodes have.
+ */
+static INLINE void
+set_new_node (ir_node *old, ir_node *new)
+{
+ old->link = new;
+}
+
+/**
+ * Copies the node to the new obstack. The Ins of the new node point to
+ * the predecessors on the old obstack. For block/phi nodes not all
+ * predecessors might be copied. n->link points to the new node.
+ * For Phi and Block nodes the function allocates in-arrays with an arity
+ * only for useful predecessors. The arity is determined by counting
+ * the non-bad predecessors of the block.
+ *
+ * @param n The node to be copied
+ * @param env if non-NULL, the node number attribute will be copied to the new node
+ */
+static void
+copy_node (ir_node *n, void *env)
+{
+ ir_node *nn;
+ int new_arity;
+ ir_op *op = get_irn_op(n);
+ int copy_node_nr = false;
+
+ /* The end node looses it's flexible in array. This doesn't matter,
+ as dead node elimination builds End by hand, inlineing doesn't use
+ the End node. */
+ /* assert(op == op_End || ((_ARR_DESCR(n->in))->cookie != ARR_F_MAGIC)); */
+
+ if (op == op_Bad)
+ /* node copied already */
+ return;
+
+ new_arity = get_irn_arity(n);
+
+ nn = new_ir_node(get_irn_dbg_info(n),
+ current_ir_graph,
+ NULL, /* no block yet, will be set later */
+ op,
+ get_irn_mode(n),
+ new_arity,
+ get_irn_in(n));
+
+
+ /* Copy the attributes. These might point to additional data. If this
+ was allocated on the old obstack the pointers now are dangling. This
+ frees e.g. the memory of the graph_arr allocated in new_immBlock. */
+ copy_node_attr(n, nn);
+ new_backedge_info(nn);
+ set_new_node(n, nn);
+
+#if DEBUG_libfirm
+ if (copy_node_nr) {
+ /* for easier debugging, we want to copy the node numbers too */
+ nn->node_nr = n->node_nr;
+ }
+#endif
+
+}
+/*Check if phi in the loop head is.
+ *
+ * @param phi Must be a phi node from the loop.
+ * @param loop_head The loop head .
+ */
+static int is_Phi_in_loop_head(ir_node *phi, ir_node *loop_head) {
+ assert(is_Block(loop_head));
+ return is_Phi(phi) && (get_nodes_block(phi) == loop_head);
+}
+
+/**
+ * Copies predecessors of node to copies of node.
+ * If the predecessor is a loop invariant, then the copy get it
+ * as predecessor, else the copy of the predecessor.
+ *
+ * @param l_n A set, where the node of the loop are saved.
+ * @param value A element of the set.
+ * @param info Contains information about the induction variable.
+ * @param unroll_factor A integer 2 <= unroll_factor <= 4.
+ * @param env Free environment pointer.
+ */
+static void
+set_preds (set *l_n, copies_t *value, induct_var_info *info, int unroll_factor, void *env)
+{
+ int i, p, irn_arity;
+ copies_t key, *value_pred;
+ // The head of the unrolling loop.
+ ir_node *loop_head = get_loop_node(info->l_itervar_phi, 0);
+
+ irn_arity = get_irn_arity(value->irn);
+
+ for (i = 0; i < irn_arity; i++) {
+ ir_node *pred = get_irn_n(value->irn, i);
+
+ key.irn = pred;
+ value_pred = set_find(l_n, &key, sizeof(key), HASH_PTR(pred));
+
+ if (value->irn != loop_head && !is_Phi_in_loop_head(value->irn, loop_head)) {
+ if (value_pred == NULL) {
+ /* Is loop invariant. */
+ for (p = 0; p < unroll_factor - 1; p++)
+ set_irn_n(value->copy[p], i, pred);
+ /* pred is a loop invariant. The copies of the successors get it as predecessor. */
+ }
+ else {
+ for (p = 0; p < unroll_factor - 1; p++)
+ set_irn_n(value->copy[p], i, value_pred->copy[p]);
+ /* value_pred->irn is a node from the unrolling loop.
+ * The copies of the successors get the
+ * copies of value_pred as predecessor.
+ */
+ }
+ }
+ }
+}
+
+/* Set the backedge of phi in the loop head.The backedge of phis in the loop head
+ * must now point to the value defined
+ * in the last copy of the loop body.
+ *
+ * @param l_n A set, where the node of the loop are saved.
+ * @param value A phi in the loop head.
+ * @param info Contains information about the induction variable.
+ * @param unroll_factor A integer 2 <= unroll_factor <= 4.
+ */
+static void
+set_phi_backedge(set *l_n, copies_t *value, induct_var_info *info, int unroll_factor)
+{
+ copies_t key, *value_pred;
+
+ /* info->op_pred_pos is the backedge position. */
+ key.irn = get_irn_n(value->irn, info->op_pred_pos);
+ value_pred = set_find(l_n, &key, sizeof(key), HASH_PTR(key.irn));
+
+ /* value->copy[unroll_factor - 2] is the last copy. */
+ set_Phi_pred(value->irn, info->op_pred_pos, value_pred->copy[unroll_factor - 2]);
+}
+
+/**
+ * Test for a loop head.
+ *
+ * Returns true if the node has predecessors in the loop _and_ out of
+ * the loop. Then it is a loop head: The loop can be entered through
+ * this node.
+ *
+ * @param n The node to be tested. Must be a block.
+ * @param info Contains the loop information.
+ */
+static int
+is_loop_head(ir_node *n, induct_var_info *info)
+{
+ int i, arity;
+ int some_outof_loop = 0, some_in_loop = 0;
+
+ assert(get_irn_op(n) == op_Block);
+ arity = get_Block_n_cfgpreds(n);
+
+ for (i = 0; i < arity; i++) {
+ ir_node *pred = get_Block_cfgpred(n, i);
+ assert(pred);
+ if (is_loop_invariant(pred, get_loop_node(info->l_itervar_phi, 0))) {
+ some_outof_loop = 1;
+ } else
+ some_in_loop = 1;
+ }
+
+ return some_outof_loop && some_in_loop;
+}
+
+
+/**
+ * Test whether the passed loop is a natural loop.
+ *
+ * Returns true if the loop has only one loop header and only a single
+ * back edge.
+ *
+ * @param info Contains the loop information.
+ */
+static int
+is_natural_loop(induct_var_info *info)
+{
+ ir_node *l_node;
+ int l_n_node = 0, i;
+
+ l_n_node = get_loop_n_nodes (info->l_itervar_phi);
+
+ for (i = 1; i < (l_n_node); i ++) {
+ l_node = get_loop_node (info->l_itervar_phi, i);
+ if (is_loop_head(l_node, info)) return 0;
+
+ if (has_backedges(l_node) && i != l_n_node-1) return 0;
+ }
+
+ return 1;
+}
+
+/**
+ * Search for all nodes of a loop.
+ *
+ * @param node The induction variable of the loop.
+ * @param loop_head The head of the loop.
+ * @param l_n A set, where the node of the loop are saved.
+ */
+static void
+find_loop_nodes(ir_node *node, ir_node *loop_head, set *l_n)
+{
+ int i;
+ copies_t key, *value;
+
+ /* Add this node to the list. */
+ key.irn = node;
+
+ /* Initialize all copies of the added node with NULL.*/
+ for (i = 0; i < 4; ++i)
+ key.copy[i] = NULL;
+ value = set_insert(l_n, &key, sizeof(key), HASH_PTR(key.irn));
+
+ /* Add all outs of this node to the list, if they are within the loop. */
+ for (i = get_irn_n_outs(node) - 1; i >= 0; --i) {
+ ir_node *pred = get_irn_out(node, i);
+
+ key.irn = pred;
+ if (!is_loop_invariant(pred, loop_head) &&
+ set_find( l_n, &key, sizeof(key), HASH_PTR(key.irn)) == NULL ) {
+ find_loop_nodes(pred, loop_head, l_n);
+ }
+ }
+
+ /* Add all ins if they are within the loop. */
+ for (i = get_irn_arity(node) - 1; i >=0; --i) {
+ ir_node *pred = get_irn_n(node, i);
+
+ key.irn = pred;
+ if (!is_loop_invariant(pred, loop_head) &&
+ set_find( l_n, &key, sizeof(key), HASH_PTR(key.irn)) == NULL ) {
+ find_loop_nodes(pred, loop_head, l_n);
+ }
+ }
+}
+
+/**
+ * Make a new loop head if copy_head = 1.
+ *
+ * @param l_n A set, where the node of the loop are saved.
+ * @param info Contains the loop information.
+ * @param value A element of the set.
+ * @param unroll_factor A integer 2 <= unroll_factor <= 4.
+ * @param copy_head if non-zero, the loop head will be copied
+ *
+ */
+static void
+new_loop_head(set *l_n, induct_var_info *info, copies_t *value, int unroll_factor, int copy_head)
+{
+ int i;
+ copies_t block, *value_backedge_jmp, *backedge_jmp_block;
+ /* The predecessor of the loop head in the backedge position */
+ ir_node *backedge_jmp = get_Block_cfgpred(value->irn, info->op_pred_pos);
+
+ block.irn = backedge_jmp;
+ value_backedge_jmp = set_find(l_n, &block, sizeof(block), HASH_PTR(block.irn));
+
+ if (copy_head) {
+ /* The first copy of the loop head must point to the loop head.*/
+ value->copy[0] = new_Block(1, &backedge_jmp);
+
+ for (i = 1; i < unroll_factor - 1; ++i) {
+ /* all other copies must point to the copy before it in the array. */
+ value->copy[i] = new_Block(1, &value_backedge_jmp->copy[i-1]);
+ }
+ }
+ else {
+ /* If the loop head must not be copy. block.irn is the successor of the loop head.*/
+ block.irn = get_nodes_block(backedge_jmp);
+ backedge_jmp_block = set_find(l_n, &block, sizeof(block), HASH_PTR(block.irn));
+
+ /* The first copy of block.irn point to it.
+ The another copies muss point to the copy before it in the array.*/
+ set_irn_n(backedge_jmp_block->copy[0], 0, value_backedge_jmp->irn) ;
+
+ for (i = 1; i < unroll_factor - 1; ++i)
+ set_irn_n(backedge_jmp_block->copy[i], 0, value_backedge_jmp->copy[i - 1]);
+ }
+}
+
+/* Set all copies of the induction variable.
+ *
+ * @param phi A phi node in the loop head block.
+ * @param phi_pred The predecessor of the phi along the backedge.
+ * @param unroll_factor A integer 2 <= unroll_factor <= 4.
+ */
+static void
+set_Phi_copies(copies_t *phi, copies_t *phi_pred, int unroll_factor)
+{
+ int p;
+
+ /* The first copy of Phi node get the node along the backedge as predecessor. The next copies
+ the copies of this node.*/
+ phi->copy[0] = phi_pred->irn;
+ for (p = 1; p < unroll_factor - 1; ++p) {
+ /* If two phi nodes are in cycle. */
+ if (phi_pred->copy[p - 1] == NULL && get_irn_op(phi_pred->irn) == op_Phi) {
+ if (p & 1)
+ phi->copy[p] = phi->irn;
+ else
+ phi->copy[p] = phi_pred->irn;
+ } else
+ phi->copy[p] = phi_pred->copy[p - 1];
+ }
+}
+
+/**
+ * Decide if the loop head must be copied. A head with important nodes
+ * must be copied.
+ *
+ * @param l_n A set, where the node of the loop are saved.
+ * @param info Contains information about the induction variable.
+ *
+ * @return non-zero if the loop head must be copied
+ */
+static int
+loop_head_nodes(set *l_n, induct_var_info *info)
+{
+ int must_copy = 0;
+ copies_t *value;
+ ir_node *loop_head = get_loop_node(info->l_itervar_phi, 0);
+
+ for (value = set_first(l_n); value != NULL; value = set_next(l_n))
+ if (is_no_Block(value->irn) && get_nodes_block(value->irn) == loop_head)
+ /* If the loop head contains just this nodes, than must not be copy. */
+ switch (get_irn_opcode(value->irn)) {
+ case iro_Cond:
+ break;
+ case iro_Phi:
+ break;
+ case iro_Proj:
+ break;
+ case iro_Const:
+ break;
+ case iro_Cmp:
+ break;
+ default:
+ must_copy = 1;
+ }
+ return must_copy;
+}