3 * @file loop_unrolling.c
6 * File name: ir/opt/loop_unrolling.c
7 * Purpose: Make loop unrolling.
8 * Author: Beyhan Veliev
12 * Copyright: (c) 2004 Universität Karlsruhe
13 * Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE.
29 #include "loop_unrolling.h"
41 #include "strength_red.h"
42 #include "compute_loop_info.h"
46 /* We will unroll maximal 4-times. */
49 /* We will know if the head of the loop to be copy.
50 * Default "0" don't copy.*/
51 static int copy_loop_head;
54 ir_node *irn ; /* Node of the loop to be unrolling*/
55 ir_node *copy[MAX_UNROLL] ; /* The copy of the node */
59 * Compare two elements of the copies_t set
61 static int set_cmp(const void *elt, const void *key, size_t size)
63 const copies_t *c1 = elt;
64 const copies_t *c2 = key;
66 return c1->irn != c2->irn;
70 * Remember the new node in the old node by using a field all nodes have.
73 set_new_node (ir_node *old, ir_node *new)
78 /*Check if phi in the loop head is.
80 * @param phi Must be a phi node from the loop.
81 * @param loop_head The loop head .
83 static int is_Phi_in_loop_head(ir_node *phi, ir_node *loop_head) {
84 assert(is_Block(loop_head));
85 return is_Phi(phi) && (get_nodes_block(phi) == loop_head);
89 * Copies predecessors of node to copies of node.
90 * If the predecessor is a loop invariant, then the copy get it
91 * as predecessor, else the copy of the predecessor.
93 * @param l_n A set, where the node of the loop are saved.
94 * @param value A element of the set.
95 * @param info Contains information about the induction variable.
96 * @param unroll_factor A integer 2 <= unroll_factor <= 4.
97 * @param env Free environment pointer.
100 set_preds (set *l_n, copies_t *value, induct_var_info *info, int unroll_factor, void *env)
104 copies_t key, *value_pred;
105 if(value->copy[0] == NULL ||
106 get_irn_op(value->irn) != get_irn_op(value->copy[0]))
109 /* The head of the unrolling loop. */
110 loop_head = get_loop_node(info->l_itervar_phi, 0);
111 irn_arity = get_irn_arity(value->irn);
113 for (i = 0; i < irn_arity; i++) {
114 ir_node *pred = get_irn_n(value->irn, i);
117 value_pred = set_find(l_n, &key, sizeof(key), HASH_PTR(pred));
119 if (value->irn != loop_head && !is_Phi_in_loop_head(value->irn, loop_head)) {
120 if (value_pred == NULL) {
121 /* Is loop invariant. */
122 for (p = 0; p < unroll_factor - 1; p++)
123 set_irn_n(value->copy[p], i, pred);
124 /* pred is a loop invariant. The copies of the successors get it as predecessor. */
127 for (p = 0; p < unroll_factor - 1; p++)
128 set_irn_n(value->copy[p], i, value_pred->copy[p]);
129 /* value_pred->irn is a node from the unrolling loop.
130 * The copies of the successors get the
131 * copies of value_pred as predecessor.
138 /* Set the backedge of phi in the loop head.The backedge of phis in the loop head
139 * must now point to the value defined
140 * in the last copy of the loop body.
142 * @param l_n A set, where the node of the loop are saved.
143 * @param value A phi in the loop head.
144 * @param info Contains information about the induction variable.
145 * @param unroll_factor A integer 2 <= unroll_factor <= 4.
148 set_phi_backedge(set *l_n, copies_t *value, induct_var_info *info, int unroll_factor)
150 copies_t key, *value_pred;
152 /* info->op_pred_pos is the backedge position. */
153 key.irn = get_irn_n(value->irn, info->op_pred_pos);
154 value_pred = set_find(l_n, &key, sizeof(key), HASH_PTR(key.irn));
156 /* value->copy[unroll_factor - 2] is the last copy. */
157 set_Phi_pred(value->irn, info->op_pred_pos, value_pred->copy[unroll_factor - 2]);
161 * Test for a loop head.
163 * Returns true if the node has predecessors in the loop _and_ out of
164 * the loop. Then it is a loop head: The loop can be entered through
167 * @param n The node to be tested. Must be a block.
168 * @param info Contains the loop information.
171 is_loop_head(ir_node *n, induct_var_info *info)
174 int some_outof_loop = 0, some_in_loop = 0;
176 assert(get_irn_op(n) == op_Block);
177 arity = get_Block_n_cfgpreds(n);
179 for (i = 0; i < arity; i++) {
180 ir_node *pred = get_Block_cfgpred(n, i);
182 if (is_loop_invariant(pred, get_loop_node(info->l_itervar_phi, 0))) {
188 return some_outof_loop && some_in_loop;
193 * Test whether the passed loop is a natural loop.
195 * Returns true if the loop has only one loop header and only a single
198 * @param info Contains the loop information.
201 is_natural_loop(induct_var_info *info)
206 l_n_node = get_loop_n_nodes (info->l_itervar_phi);
208 for (i = 1; i < (l_n_node); i ++) {
209 l_node = get_loop_node (info->l_itervar_phi, i);
210 if (is_loop_head(l_node, info)) return 0;
212 if (has_backedges(l_node) && i != l_n_node-1) return 0;
219 * Search for all nodes of a loop.
221 * @param node The induction variable of the loop.
222 * @param loop_head The head of the loop.
223 * @param l_n A set, where the node of the loop are saved.
226 find_loop_nodes(ir_node *node, ir_node *loop_head, set *l_n)
229 copies_t key, *value;
231 /* Add this node to the list. */
234 /* Initialize all copies of the added node with NULL.*/
235 for (i = 0; i < 4; ++i)
237 value = set_insert(l_n, &key, sizeof(key), HASH_PTR(key.irn));
239 /* Add all outs of this node to the list, if they are within the loop. */
240 for (i = get_irn_n_outs(node) - 1; i >= 0; --i) {
241 ir_node *pred = get_irn_out(node, i);
244 if (!is_loop_invariant(pred, loop_head) &&
245 set_find( l_n, &key, sizeof(key), HASH_PTR(key.irn)) == NULL ) {
246 find_loop_nodes(pred, loop_head, l_n);
250 /* Add all ins if they are within the loop. */
251 for (i = get_irn_arity(node) - 1; i >=0; --i) {
252 ir_node *pred = get_irn_n(node, i);
255 if (!is_loop_invariant(pred, loop_head) &&
256 set_find( l_n, &key, sizeof(key), HASH_PTR(key.irn)) == NULL ) {
257 find_loop_nodes(pred, loop_head, l_n);
263 * Make a new loop head if copy_head = 1.
265 * @param l_n A set, where the node of the loop are saved.
266 * @param info Contains the loop information.
267 * @param value A element of the set.
268 * @param unroll_factor A integer 2 <= unroll_factor <= 4.
269 * @param copy_head if non-zero, the loop head will be copied
273 new_loop_head(set *l_n, induct_var_info *info, copies_t *value, int unroll_factor, int copy_head)
276 copies_t block, *value_backedge_jmp, *backedge_jmp_block;
277 /* The predecessor of the loop head in the backedge position */
278 ir_node *backedge_jmp = get_Block_cfgpred(value->irn, info->op_pred_pos);
280 block.irn = backedge_jmp;
281 value_backedge_jmp = set_find(l_n, &block, sizeof(block), HASH_PTR(block.irn));
284 /* The first copy of the loop head must point to the loop head.*/
285 value->copy[0] = new_Block(1, &backedge_jmp);
286 if(info->l_itervar_phi->flags & do_loop){
287 value_backedge_jmp->copy[0] = new_r_Jmp(current_ir_graph, value->copy[0]);
288 for (i = 1; i < unroll_factor - 1; ++i) {
289 /* all other copies must point to the copy before it in the array. */
290 value->copy[i] = new_Block(1, &backedge_jmp);
291 value_backedge_jmp->copy[i] = new_r_Jmp(current_ir_graph, value->copy[i]);
293 for (i = 1; i < unroll_factor - 1; ++i){
294 set_nodes_block(value_backedge_jmp->copy[i-1], get_nodes_block(backedge_jmp));
295 set_Block_cfgpred (value->copy[i], 0, value_backedge_jmp->copy[i-1]);
298 for (i = 1; i < unroll_factor - 1; ++i) {
299 /* all other copies must point to the copy before it in the array. */
300 set_nodes_block(value_backedge_jmp->copy[i-1], get_nodes_block(backedge_jmp));
301 value->copy[i] = new_Block(1, &value_backedge_jmp->copy[i-1]);
305 /* If the loop head must not be copy. block.irn is the successor of the loop head.*/
306 block.irn = get_nodes_block(backedge_jmp);
307 backedge_jmp_block = set_find(l_n, &block, sizeof(block), HASH_PTR(block.irn));
309 /* The first copy of block.irn point to it.
310 The another copies muss point to the copy before it in the array.*/
311 set_irn_n(backedge_jmp_block->copy[0], 0, value_backedge_jmp->irn) ;
313 for (i = 1; i < unroll_factor - 1; ++i)
314 set_irn_n(backedge_jmp_block->copy[i], 0, value_backedge_jmp->copy[i - 1]);
318 /* Set all copies of the induction variable.
320 * @param phi A phi node in the loop head block.
321 * @param phi_pred The predecessor of the phi along the backedge.
322 * @param unroll_factor A integer 2 <= unroll_factor <= 4.
325 set_Phi_copies(copies_t *phi, copies_t *phi_pred, int unroll_factor)
329 if(phi_pred != NULL){
330 /* The first copy of Phi node get the node along the backedge as predecessor. The next copies
331 the copies of this node.*/
332 phi->copy[0] = phi_pred->irn;
333 for (p = 1; p < unroll_factor - 1; ++p) {
334 /* If two phi nodes are in cycle. */
335 if (phi_pred->copy[p - 1] == NULL && get_irn_op(phi_pred->irn) == op_Phi) {
337 phi->copy[p] = phi->irn;
339 phi->copy[p] = phi_pred->irn;
341 phi->copy[p] = phi_pred->copy[p - 1];
344 /* The predecessors of phi are loop invariant and the copies von phi
345 must be phi it self.*/
346 for(p = 0; p < unroll_factor - 1; ++p)
347 phi->copy[p] = phi->irn;
351 * Decide if the loop head must be copied. A head with important nodes
354 * @param l_n A set, where the node of the loop are saved.
355 * @param info Contains information about the induction variable.
357 * @return non-zero if the loop head must be copied
360 loop_head_nodes(set *l_n, induct_var_info *info)
364 ir_node *loop_head = get_loop_node(info->l_itervar_phi, 0);
366 for (value = set_first(l_n); value != NULL; value = set_next(l_n))
367 if (is_no_Block(value->irn) && get_nodes_block(value->irn) == loop_head)
368 /* If the loop head contains just this nodes, than must not be copy. */
369 switch (get_irn_opcode(value->irn)) {
386 /** Copy all loop nodes.
388 * @param l_n Contains all nodes of the loop.
389 * @param info Contains the loop information.
390 * @param unroll_factor A integer 2 <= unroll_factor <= 4.
393 copy_loop_body(set *l_n, induct_var_info *info, int unroll_factor)
396 copies_t *value, *info_op, *phi, *loop_h = NULL, key, *value_block;
397 ir_node *proj_b, *cond, *proj_1, *proj_0, *loop_head;
398 proj_b = get_irn_out(info->cmp, 0);
399 cond = get_irn_out(proj_b, 0);
400 proj_0 = get_irn_out(cond, 0);
401 proj_1 = get_irn_out(cond, 1);
403 loop_head = get_loop_node(info->l_itervar_phi, 0);
404 /* I will create some nodes and need the optimization to
406 opt = get_optimize();
409 for (value = set_first(l_n); value != NULL; value = set_next(l_n)) {
410 if(value->irn == loop_head)
412 else if (is_Phi_in_loop_head(value->irn, loop_head))
414 else if (copy_loop_head){
415 if(value->irn == proj_0){
416 for (i = 0; i < unroll_factor - 1; i++)
417 /* In the copies of the loop head we replace the cmp branche with a jmp node.
418 This is just for "for" loops."do" loops are handled in function
420 value->copy[i] = new_r_Jmp(current_ir_graph, get_nodes_block(value->irn));
421 }else if(value->irn != proj_b && value->irn != cond &&
422 value->irn != proj_1)
423 /* The loop head must be copied. */
424 for (i = 0; i < unroll_factor - 1; i++){
425 copy_irn_to_irg(value->irn, current_ir_graph);
426 value->copy[i] = get_irn_link(value->irn);
429 /* The loop head and its nodes must not be copied. */
430 if((value->irn->op == op_Block &&
431 value->irn != loop_head) ||
432 (value->irn->op != op_Block &&
433 get_nodes_block(value->irn) != loop_head)) {
434 for (i = 0; i<unroll_factor -1; i++) {
435 copy_irn_to_irg(value->irn, current_ir_graph);
436 value->copy[i] = get_irn_link(value->irn);
442 /* Treat the loop head block */
443 new_loop_head(l_n, info, loop_h, unroll_factor, copy_loop_head);
444 /* I have created the nodes and I set the optimization
448 /* Similarly treat the Phis in the loop head block. info->op is the node
449 along the backedges. */
451 info_op = set_find( l_n, &key, sizeof(key), HASH_PTR(key.irn));
452 assert(info_op->irn == get_Phi_pred(info->itervar_phi, info->op_pred_pos));
453 for (i = 0; i < get_irn_n_outs(loop_head); ++i) {
454 ir_node *phi = get_irn_out(loop_head, i);
457 copies_t *phi_pred, *phi_op;
459 key.irn = get_Phi_pred(phi, info->op_pred_pos); // info->op;
460 phi_pred = set_find(l_n, &key, sizeof(key), HASH_PTR(key.irn));
462 phi_op = set_find(l_n, &key, sizeof(key), HASH_PTR(key.irn));
463 set_Phi_copies(phi_op, phi_pred, unroll_factor);
467 for (value = set_first(l_n); value != NULL; value = set_next(l_n)) {
469 /* Set the predecessors of the copies. */
471 set_preds(l_n, value, info, unroll_factor, NULL);
472 }else if ((value->irn->op != op_Block) && get_nodes_block(value->irn) != loop_head)
473 set_preds(l_n, value, info, unroll_factor, NULL);
475 if (is_Phi_in_loop_head(value->irn, loop_head) &&
476 has_backedges(value->irn))
477 /* Set the backedge of phis in the loop head. */
478 set_phi_backedge(l_n, value, info, unroll_factor);
480 if ((value->irn->op != op_Block) && !is_Phi_in_loop_head(value->irn, loop_head) &&
481 value->copy[0] != NULL ) {
482 ir_node *nodes_block = get_nodes_block(value->irn);
484 if (!copy_loop_head && nodes_block == loop_head)
487 key.irn = nodes_block;
488 value_block = set_find( l_n, &key, sizeof(key), HASH_PTR(key.irn));
489 /* Set the copy of the node in the accordant copy of its block. */
490 for(i = 0; i < unroll_factor - 1; i++){
491 set_nodes_block(value->copy[i], value_block->copy[i]);
495 /* I must repair some control flow edges, when the loop head
497 if (copy_loop_head && !(info->l_itervar_phi->flags & do_loop)){
499 value = set_find( l_n, &key, sizeof(key), HASH_PTR(key.irn));
500 key.irn = get_irn_out(proj_0, 0);
501 info_op = set_find( l_n, &key, sizeof(key), HASH_PTR(key.irn));
502 for (i = 0; i < unroll_factor - 1; i++){
503 set_Block_cfgpred(info_op->copy[i], 0, value->copy[i]);
509 * Returns non-zero if a Proj node from the loop has a predecessor that
510 * can throw an exception.
512 * @param node A Proj node from the loop.
514 * @return non-zero if the predecessor of the Proj node can throw an exception
516 static int is_exception_possible(ir_node *node)
518 ir_node *pred = get_Proj_pred(node);
520 /* only fragile ops can throw an exception */
521 if (! is_fragile_op(pred))
525 * fragile ops that are known NOT to throw
526 * an exception if their pin_state is op_pin_state_floats
528 return get_irn_pinned(pred) != op_pin_state_floats;
532 * If a node from the loop is predecessor of the end block, then the end block must get all copies
533 * of this node as predecessors. This is possible with function calls in the unrolling loop.
535 * @param end_block The end block.
536 * @param loop_head The head of the unrolling loop.
537 * @param l_n Contains all nodes of the loop.
538 * @param loop_endblock_outs The set loop_endblock_outs contains all predecessors
539 * of the end block from the unrolling loop.
540 * @param unroll_factor A integer 2 <= unroll_factor <= 4.
543 new_end_block(ir_node *end_block, ir_node *loop_head, set *l_n, set *loop_endblock_outs, int unroll_factor)
545 copies_t key, *value;
546 int set_el, new_preds, all_new_preds, i, q;
547 int old_preds = get_Block_n_cfgpreds(end_block); /* All old predecessors of the end block. */
550 for (i = 0; i < old_preds; i++) {
551 ir_node *pred = get_Block_cfgpred(end_block, i);
554 value = set_find( l_n, &key, sizeof(key), HASH_PTR(key.irn));
556 /* If a predecessor of the end block is a Proj from the unrolling loop (for function calls) .*/
557 if (get_irn_op(pred) == op_Proj && is_exception_possible(pred) && value != NULL &&
558 !(!copy_loop_head && get_nodes_block(pred) == loop_head))
559 value = set_insert(loop_endblock_outs, &key, sizeof(key), HASH_PTR(key.irn));
562 /* The set loop_endblock_outs contains all predecessors of the end block from the unrolling loop,
563 * set_el the amount of such nodes.
565 set_el = set_count (loop_endblock_outs);
567 /* If the end block haven't such predecessors, we are finished. */
570 new_preds = (unroll_factor - 1) * set_el; /* All new predecessors of the end block */
571 all_new_preds = old_preds + new_preds; /* All predecessors of this block. */
572 all_in = alloca(sizeof(*all_in) * all_new_preds); /* A array with size for all predecessors of this block. */
574 for (i = 0; i < old_preds; i++)
575 all_in[i] = get_Block_cfgpred(end_block, i); /* The old predecessors. */
577 value = set_first(loop_endblock_outs);
579 for (; value != NULL; value = set_next(loop_endblock_outs)) {
580 key.irn = value->irn;
581 value = set_find( l_n, &key, sizeof(key), HASH_PTR(key.irn));
582 for (q = 0; q < unroll_factor - 1 ; q++) {
583 all_in[i++] = value->copy[q]; /* The new predecessors. */
588 /* Replace the old predecessors of the end block wit´h the new ones. */
589 set_irn_in(end_block, all_new_preds, all_in);
592 /** new_after_loop_block
594 * The after loop block must examine the possible exceptions in the loop.
595 * If a (Proj) node from the loop is predecessor of this block, then the
596 * after loop block must have as well all copies of this node as predecessors.
598 * @param l_n Contains all nodes of the loop.
599 * @param block A block after the loop.
600 * @param loop_in A node from the loop, that is predecessor of the end block.
601 * @param unroll_factor An integer 2 <= unroll_factor <= 4.
604 new_after_loop_block (set *l_n, ir_node* block, copies_t *loop_in, int unroll_factor)
606 copies_t key, *value;
607 int i, p, q, s, old_preds, new_preds, all_new_preds ;
610 /* The node from the unrolling loop must be a Proj. */
611 if (loop_in->irn->op != op_Proj) return;
613 old_preds = get_Block_n_cfgpreds(block); /* All old predecessors of this block. */
614 new_preds = old_preds * (unroll_factor - 1); /* All new predecessors of this block. */
615 all_new_preds = old_preds + new_preds; /* All predecessors of this block. */
617 all_in = alloca(sizeof(*all_in) * all_new_preds); /* An array with size for all predecessors of this block. */
619 for (i = 0 ; i < old_preds; i++)
620 all_in[i] = get_Block_cfgpred(block, i); /* The old predecessors. */
623 for (i = 0; i < old_preds; i++){
625 value = set_find( l_n, &key, sizeof(key), HASH_PTR(key.irn));
627 for (s = 0; s < (unroll_factor - 1); s++) {
628 all_in[q++] = value->copy[p++]; /* The new predecessors. */
631 /* Replace the old predecessors of the end block whit the new one. */
632 set_irn_in(block, all_new_preds, all_in);
635 /** new_after_loop_node
637 * An after loop node (phi or call) must examine the possible exceptions in the loop.
638 * If a (Proj) node from the loop is predecessor of this node, then the after loop
639 * node must have as well all copies of this node as predecessors.
641 * @param l_n Contains all nodes of the loop.
642 * @param loop_outs Contains nodes after the loop,that have as predecessor a node from the loop.
643 * @param node A node after the loop.
644 * @param loop_in A node (Proj) from the loop, that is predecessor of *node.
645 * @param unroll_factor An integer 2 <= unroll_factor <= 4.
648 new_after_loop_node(set *l_n, set *loop_outs, ir_node *node, copies_t *loop_in, int unroll_factor)
650 ir_node *pred, *block_pred = NULL, *node_block, *new_phi;
651 int phi = 0, old_preds, new_preds, all_new_preds, p, q, i, s;
652 copies_t key, *value = NULL;
655 old_preds = get_irn_arity(node); /* All old predecessors of this node. */
656 new_preds =old_preds * (unroll_factor - 1); /* All new predecessors of this block. */
657 all_new_preds = old_preds + new_preds; /* All predecessors of this block. */
659 all_in = alloca(sizeof(*all_in) * all_new_preds); /* An array with size for all predecessors of this block. */
661 /* Verification Predecessors, successors and operation of node and loop_in.
662 * loop_in must be a Proj node.
664 if (loop_in->irn->op != op_Proj) return;
665 /* Node must be operation Phi with mode memory or a Call node. */
666 if (get_irn_op(node) == op_Phi &&
667 get_irn_mode(node) == mode_M){
668 /* If node is a Phi node,then must have a Call node as successor. */
669 for (i = 0; i < get_irn_n_outs(node); i++)
670 if (get_irn_op(get_irn_out(node, i)) == op_Call) {
678 /* The predecessor of loop_in must not be a loop invariant. */
679 pred = get_Proj_pred(loop_in->irn);
681 value = set_find( l_n, &key, sizeof(key), HASH_PTR(key.irn));
684 node_block = get_nodes_block(node);
686 /* The block of node must also have a (Proj) predecessor from the unrolling loop. */
687 for (i = 0; i < get_Block_n_cfgpreds(node_block); i++) {
688 block_pred = get_Block_cfgpred(node_block, i);
690 if (get_irn_op(block_pred) == op_Proj) {
691 if (get_Proj_pred(block_pred) == pred)
699 if (! block_pred) return;
701 key.irn = block_pred;
702 value = set_find(l_n, &key, sizeof(key), HASH_PTR(key.irn));
707 new_after_loop_block(l_n, node_block, value, unroll_factor);
709 for (i = 0; i < old_preds; ++i)
710 all_in[i] = get_irn_n(node, i); /* The old predecessors. */
713 for (i = 0; i < old_preds; ++i) {
715 value = set_find( l_n, &key, sizeof(key), HASH_PTR(key.irn));
717 for (s = 0; s < (unroll_factor - 1); ++s) {
718 all_in[q] = value->copy[p]; /* The new predecessors. */
723 /* A new phi node with the new predecessors. */
724 new_phi = new_r_Phi(current_ir_graph, get_nodes_block(node), all_new_preds,all_in,
728 exchange(node, new_phi);
730 for (i = 0; i < get_irn_arity(node); ++i)
731 if (get_irn_n(node, i) == pred)
732 set_irn_n(node, i, new_phi);
735 /* The set loop_outs contains the visited nodes and their blocks. */
737 value = set_insert(loop_outs, &key, sizeof(key), HASH_PTR(key.irn));
738 key.irn = get_nodes_block(node);
739 value = set_insert(loop_outs, &key, sizeof(key), HASH_PTR(key.irn));
743 /* Set the outs of the unrolling loop. All loop outs of a node muss now
744 * point to the last copy of it. Just phi nodes in the loop head and proj
745 * nodes save it outs. The all copies of some Projs have too outs.
747 * @param l_n Contains all nodes of the loop.
748 * @param loop_outs The set contains the visited and changed loop outs.
749 * @param loop_endblock_outs The set loop_endblock_outs contains all predecessors
750 * of the end block from the unrolling loop.
751 * @param info Contains the loop information.
752 * @param unroll_factor A integer 2 <= unroll_factor <= 4.
755 set_loop_outs(set *l_n, set *loop_outs, set *loop_endblock_outs, induct_var_info *info, int unroll_factor)
757 copies_t *value, key;
759 ir_node *loop_head = get_loop_node(info->l_itervar_phi, 0);
760 ir_node *end_block = get_irg_end_block(current_ir_graph);
762 for (value = set_first(l_n); value != NULL; value = set_next(l_n)){
763 if(get_irn_node_nr(value->irn) == 35047)
765 if (! is_Phi_in_loop_head(value->irn, loop_head) &&
766 (get_irn_opcode(value->irn) == iro_Proj && value->copy[0] != NULL))
767 for (i = 0; i < get_irn_n_outs(value->irn); ++i) {
768 key.irn = get_irn_out(value->irn, i);
770 /* Search for loop outs. */
771 if (set_find( l_n, &key, sizeof(key), HASH_PTR(key.irn)) == NULL)
772 if ((key.irn->op == op_Block && get_Block_dom_depth(key.irn) >
773 get_Block_dom_depth(loop_head)) ||
774 (key.irn->op != op_Block && get_Block_dom_depth(get_nodes_block(key.irn)) >
775 get_Block_dom_depth(loop_head))) {
777 for (p = 0; p < get_irn_arity(key.irn); p++)
778 if (value->irn == get_irn_n(key.irn, p)) {
779 if (get_irn_op(value->irn) == op_Proj && is_exception_possible(value->irn)) {
780 if (set_find(loop_outs, &key, sizeof(key), HASH_PTR(key.irn)) == NULL) {
781 /* If the loop out is for exceptions in the loop. */
782 if ((get_irn_op(key.irn) == op_Phi && get_irn_mode(key.irn) == mode_M) ||
783 get_irn_op(key.irn) == op_Call)
784 new_after_loop_node(l_n,loop_outs, key.irn, value, unroll_factor);
790 /* Loop outs in the loop head must be not changed.*/
791 if(get_nodes_block(value->irn) != loop_head)
792 set_irn_n(key.irn, p, value->copy[unroll_factor-2]);
797 /* This function searches for loop outs associated with function call in the unrolling loop. */
798 new_end_block (end_block, loop_head, l_n, loop_endblock_outs, unroll_factor);
802 * Unroll the loop body with a factor that must be power of two.
803 * Called from a post walker.
805 * @param n An IR node.
806 * @param env points to a result
808 static void do_loop_unroll(ir_node *n, void *env)
810 int *unroll_done = env;
811 induct_var_info info;
813 set *loop_nodes, *loop_outs, *loop_endblock_outs;
814 ir_node *phi_init, *loop_head;
815 ir_node *backedge_jmp;
816 int l_sons = 0, unroll_factor = 0;
817 tarval *init, *iter_end, *iter_increment,*tarval_null, *tarval_one, *tarval_three, *tarval_two, *diff, *iter_number;
821 info.itervar_phi = n;
823 /* The IR node must be a induction variable. */
824 if (get_irn_op(n) == op_Phi) {
825 if (is_induction_variable (&info) == NULL)
831 /* Brute force limiting of loop body size. */
832 if (get_loop_n_nodes(info.l_itervar_phi) > 2 ) return;
834 /* Only unroll loops that compare against a constant for exiting. */
835 if (info.cmp == NULL) return;
837 /* We only want to unroll innermost loops. */
838 l_sons = get_loop_n_sons(info.l_itervar_phi);
841 /* "do" loops are not implementit gut for this reason
842 at the time we don't unroll them.*/
843 if(info.l_itervar_phi->flags & do_loop)
846 phi_init = get_Phi_pred(info.itervar_phi, info.init_pred_pos);
848 if ((!(info.l_itervar_phi->flags & loop_is_count_loop)) ||
849 (info.l_itervar_phi->flags & loop_is_endless) ||
850 (info.l_itervar_phi->flags & loop_is_dead) ||
851 (info.l_itervar_phi->flags & once))
854 init = info.l_itervar_phi->loop_iter_start;
855 iter_end = info.l_itervar_phi->loop_iter_end;
856 iter_increment = info.l_itervar_phi->loop_iter_increment;
857 tarval_null = get_mode_null(get_tarval_mode(iter_increment));
858 tarval_one = get_mode_one(get_tarval_mode(init));
860 if(tarval_is_double(init) || tarval_is_double(iter_end) || tarval_is_double(iter_increment))
863 if((tarval_is_negative(init) && tarval_is_negative(iter_end)) ||
864 (!tarval_is_negative(init) && !tarval_is_negative(iter_end)) ||
865 (tarval_is_null(init) || tarval_is_null(iter_end)))
866 diff = tarval_abs(tarval_sub(iter_end, init));
868 diff = tarval_add(tarval_abs(iter_end),tarval_abs(init));
870 iter_increment = tarval_abs(iter_increment);
872 if(!(info.l_itervar_phi->flags & do_loop))
873 diff = tarval_add(diff, tarval_one);
874 /* Test for the value of unroll factor. */
875 if (tarval_cmp(tarval_mod(diff,iter_increment), tarval_null) == pn_Cmp_Eq)
876 iter_number = tarval_div(diff, iter_increment);
879 tarval_two = tarval_add(tarval_one, tarval_one);
880 tarval_three = tarval_add(tarval_two,tarval_one);
882 if (tarval_cmp(tarval_mod(iter_number, tarval_three), tarval_null) == pn_Cmp_Eq)
884 else if (tarval_cmp(tarval_mod(iter_number, tarval_two), tarval_null) == pn_Cmp_Eq)
888 if (get_firm_verbosity())
889 printf("\nloop unrolling with factor %d \n", unroll_factor);
891 /* ok, we will do unrolling */
894 /* The unroll factor must be less than 4. */
895 assert(unroll_factor <= MAX_UNROLL);
897 loop_head = (is_natural_loop(&info)) ? get_loop_node(info.l_itervar_phi, 0) : NULL;
899 assert(loop_head != NULL && is_Block(loop_head));
901 /* We assume, the loop head has exactly one backedge. The position of
902 the backedge is in the following variable: */
903 backedge_pos = (is_backedge(loop_head, 0)) ? 0:1;
905 /* A set with the nodes to copy. */
906 loop_nodes = new_set(set_cmp, 8);
907 /* A set with the loop outs for exceptions. */
908 loop_outs = new_set(set_cmp, 8);
910 /* A set containing all predecessors
911 of the end block from the unrolling loop. */
912 loop_endblock_outs = new_set(set_cmp, 8);
913 /* Find all nodes of the unrolling loop. */
914 find_loop_nodes(info.itervar_phi, get_loop_node(info.l_itervar_phi, 0), loop_nodes);
916 /* Decide if the loop head to be copy.*/
917 copy_loop_head = loop_head_nodes(loop_nodes, &info);
919 /* Copy all nodes of the unrolling loop, that muss be copy. */
920 copy_loop_body(loop_nodes, &info, unroll_factor);
922 backedge_jmp = get_Block_cfgpred(loop_head, backedge_pos);
924 /* Set the backedge of the loop head. */
925 for (value = set_first(loop_nodes); value != NULL; value = set_next(loop_nodes)) {
926 if (value->irn == backedge_jmp)
927 set_Block_cfgpred(loop_head, backedge_pos, value->copy[unroll_factor-2]);
929 set_loop_outs(loop_nodes, loop_outs, loop_endblock_outs, &info, unroll_factor);
932 /* Performs loop unrolling for the passed graph. */
933 void optimize_loop_unrolling(ir_graph *irg /* unroll factor, max body size */)
938 if ( !get_opt_loop_unrolling()) return;
940 rem = current_ir_graph;
941 current_ir_graph = irg;
943 /* -- Precompute some information -- */
945 /* Call algorithm that computes the loop information */
946 // construct_backedges(irg);
947 compute_loop_info(irg);
948 /* Call algorithm that computes the backedges */
949 // construct_cf_backedges(irg);
951 /* Call algorithm that computes the dominator trees. */
954 /* Call algorithm that computes the out edges */
955 assure_irg_outs(irg);
957 collect_phiprojs(irg);
959 /* -- Search expressions that can be optimized -- */
960 irg_walk_graph(irg, NULL, do_loop_unroll, &unroll_done);
963 /* unrolling was done, all info is invalid */
964 set_irg_doms_inconsistent(irg);
965 set_irg_outs_inconsistent(irg);
966 set_irg_loopinfo_state(current_ir_graph, loopinfo_cf_inconsistent);
967 set_trouts_inconsistent();
968 set_irg_callee_info_state(irg, irg_callee_info_inconsistent);
971 current_ir_graph = rem;