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22 * @file loop_unrolling.c
25 * File name: ir/opt/loop_unrolling.c
26 * Purpose: Make loop unrolling.
27 * Author: Beyhan Veliev
31 * Copyright: (c) 2004 Universität Karlsruhe
41 #include "loop_unrolling.h"
53 #include "strength_red.h"
54 #include "compute_loop_info.h"
59 /* We will unroll maximal 4-times. */
62 /* We will know if the head of the loop to be copy.
63 * Default "0" don't copy.*/
64 static int copy_loop_head;
67 ir_node *irn ; /* Node of the loop to be unrolling*/
68 ir_node *copy[MAX_UNROLL] ; /* The copy of the node */
72 * Compare two elements of the copies_t set
74 static int set_cmp(const void *elt, const void *key, size_t size)
76 const copies_t *c1 = elt;
77 const copies_t *c2 = key;
79 return c1->irn != c2->irn;
83 * Remember the new node in the old node by using a field all nodes have.
86 set_new_node (ir_node *old, ir_node *new)
91 /*Check if phi in the loop head is.
93 * @param phi Must be a phi node from the loop.
94 * @param loop_head The loop head .
96 static int is_Phi_in_loop_head(ir_node *phi, ir_node *loop_head) {
97 assert(is_Block(loop_head));
98 return is_Phi(phi) && (get_nodes_block(phi) == loop_head);
102 * Copies predecessors of node to copies of node.
103 * If the predecessor is a loop invariant, then the copy get it
104 * as predecessor, else the copy of the predecessor.
106 * @param l_n A set, where the node of the loop are saved.
107 * @param value A element of the set.
108 * @param info Contains information about the induction variable.
109 * @param unroll_factor A integer 2 <= unroll_factor <= 4.
110 * @param env Free environment pointer.
113 set_preds (set *l_n, copies_t *value, induct_var_info *info, int unroll_factor, void *env)
117 copies_t key, *value_pred;
118 if(value->copy[0] == NULL ||
119 get_irn_op(value->irn) != get_irn_op(value->copy[0]))
122 /* The head of the unrolling loop. */
123 loop_head = get_loop_node(info->l_itervar_phi, 0);
124 irn_arity = get_irn_arity(value->irn);
126 for (i = 0; i < irn_arity; i++) {
127 ir_node *pred = get_irn_n(value->irn, i);
130 value_pred = set_find(l_n, &key, sizeof(key), HASH_PTR(pred));
132 if (value->irn != loop_head && !is_Phi_in_loop_head(value->irn, loop_head)) {
133 if (value_pred == NULL) {
134 /* Is loop invariant. */
135 for (p = 0; p < unroll_factor - 1; p++)
136 set_irn_n(value->copy[p], i, pred);
137 /* pred is a loop invariant. The copies of the successors get it as predecessor. */
140 for (p = 0; p < unroll_factor - 1; p++)
141 set_irn_n(value->copy[p], i, value_pred->copy[p]);
142 /* value_pred->irn is a node from the unrolling loop.
143 * The copies of the successors get the
144 * copies of value_pred as predecessor.
151 /* Set the backedge of phi in the loop head.The backedge of phis in the loop head
152 * must now point to the value defined
153 * in the last copy of the loop body.
155 * @param l_n A set, where the node of the loop are saved.
156 * @param value A phi in the loop head.
157 * @param info Contains information about the induction variable.
158 * @param unroll_factor A integer 2 <= unroll_factor <= 4.
161 set_phi_backedge(set *l_n, copies_t *value, induct_var_info *info, int unroll_factor)
163 copies_t key, *value_pred;
165 /* info->op_pred_pos is the backedge position. */
166 key.irn = get_irn_n(value->irn, info->op_pred_pos);
167 value_pred = set_find(l_n, &key, sizeof(key), HASH_PTR(key.irn));
169 /* value->copy[unroll_factor - 2] is the last copy. */
170 set_Phi_pred(value->irn, info->op_pred_pos, value_pred->copy[unroll_factor - 2]);
174 * Test for a loop head.
176 * Returns true if the node has predecessors in the loop _and_ out of
177 * the loop. Then it is a loop head: The loop can be entered through
180 * @param n The node to be tested. Must be a block.
181 * @param info Contains the loop information.
184 is_loop_head(ir_node *n, induct_var_info *info)
187 int some_outof_loop = 0, some_in_loop = 0;
189 assert(get_irn_op(n) == op_Block);
190 arity = get_Block_n_cfgpreds(n);
192 for (i = 0; i < arity; i++) {
193 ir_node *pred = get_Block_cfgpred(n, i);
195 if (is_loop_invariant(pred, get_loop_node(info->l_itervar_phi, 0))) {
201 return some_outof_loop && some_in_loop;
206 * Test whether the passed loop is a natural loop.
208 * Returns true if the loop has only one loop header and only a single
211 * @param info Contains the loop information.
214 is_natural_loop(induct_var_info *info)
219 l_n_node = get_loop_n_nodes (info->l_itervar_phi);
221 for (i = 1; i < (l_n_node); i ++) {
222 l_node = get_loop_node (info->l_itervar_phi, i);
223 if (is_loop_head(l_node, info)) return 0;
225 if (has_backedges(l_node) && i != l_n_node-1) return 0;
232 * Search for all nodes of a loop.
234 * @param node The induction variable of the loop.
235 * @param loop_head The head of the loop.
236 * @param l_n A set, where the node of the loop are saved.
239 find_loop_nodes(ir_node *node, ir_node *loop_head, set *l_n)
242 copies_t key, *value;
244 /* Add this node to the list. */
247 /* Initialize all copies of the added node with NULL.*/
248 for (i = 0; i < 4; ++i)
250 value = set_insert(l_n, &key, sizeof(key), HASH_PTR(key.irn));
252 /* Add all outs of this node to the list, if they are within the loop. */
253 for (i = get_irn_n_outs(node) - 1; i >= 0; --i) {
254 ir_node *pred = get_irn_out(node, i);
257 if (!is_loop_invariant(pred, loop_head) &&
258 set_find( l_n, &key, sizeof(key), HASH_PTR(key.irn)) == NULL ) {
259 find_loop_nodes(pred, loop_head, l_n);
263 /* Add all ins if they are within the loop. */
264 for (i = get_irn_arity(node) - 1; i >=0; --i) {
265 ir_node *pred = get_irn_n(node, i);
268 if (!is_loop_invariant(pred, loop_head) &&
269 set_find( l_n, &key, sizeof(key), HASH_PTR(key.irn)) == NULL ) {
270 find_loop_nodes(pred, loop_head, l_n);
276 * Make a new loop head if copy_head = 1.
278 * @param l_n A set, where the node of the loop are saved.
279 * @param info Contains the loop information.
280 * @param value A element of the set.
281 * @param unroll_factor A integer 2 <= unroll_factor <= 4.
282 * @param copy_head if non-zero, the loop head will be copied
286 new_loop_head(set *l_n, induct_var_info *info, copies_t *value, int unroll_factor, int copy_head)
289 copies_t block, *value_backedge_jmp, *backedge_jmp_block;
290 /* The predecessor of the loop head in the backedge position */
291 ir_node *backedge_jmp = get_Block_cfgpred(value->irn, info->op_pred_pos);
293 block.irn = backedge_jmp;
294 value_backedge_jmp = set_find(l_n, &block, sizeof(block), HASH_PTR(block.irn));
297 /* The first copy of the loop head must point to the loop head.*/
298 value->copy[0] = new_Block(1, &backedge_jmp);
299 if(info->l_itervar_phi->flags & do_loop){
300 value_backedge_jmp->copy[0] = new_r_Jmp(current_ir_graph, value->copy[0]);
301 for (i = 1; i < unroll_factor - 1; ++i) {
302 /* all other copies must point to the copy before it in the array. */
303 value->copy[i] = new_Block(1, &backedge_jmp);
304 value_backedge_jmp->copy[i] = new_r_Jmp(current_ir_graph, value->copy[i]);
306 for (i = 1; i < unroll_factor - 1; ++i){
307 set_nodes_block(value_backedge_jmp->copy[i-1], get_nodes_block(backedge_jmp));
308 set_Block_cfgpred (value->copy[i], 0, value_backedge_jmp->copy[i-1]);
311 for (i = 1; i < unroll_factor - 1; ++i) {
312 /* all other copies must point to the copy before it in the array. */
313 set_nodes_block(value_backedge_jmp->copy[i-1], get_nodes_block(backedge_jmp));
314 value->copy[i] = new_Block(1, &value_backedge_jmp->copy[i-1]);
318 /* If the loop head must not be copy. block.irn is the successor of the loop head.*/
319 block.irn = get_nodes_block(backedge_jmp);
320 backedge_jmp_block = set_find(l_n, &block, sizeof(block), HASH_PTR(block.irn));
322 /* The first copy of block.irn point to it.
323 The another copies muss point to the copy before it in the array.*/
324 set_irn_n(backedge_jmp_block->copy[0], 0, value_backedge_jmp->irn) ;
326 for (i = 1; i < unroll_factor - 1; ++i)
327 set_irn_n(backedge_jmp_block->copy[i], 0, value_backedge_jmp->copy[i - 1]);
331 /* Set all copies of the induction variable.
333 * @param phi A phi node in the loop head block.
334 * @param phi_pred The predecessor of the phi along the backedge.
335 * @param unroll_factor A integer 2 <= unroll_factor <= 4.
338 set_Phi_copies(copies_t *phi, copies_t *phi_pred, int unroll_factor)
342 if(phi_pred != NULL){
343 /* The first copy of Phi node get the node along the backedge as predecessor. The next copies
344 the copies of this node.*/
345 phi->copy[0] = phi_pred->irn;
346 for (p = 1; p < unroll_factor - 1; ++p) {
347 /* If two phi nodes are in cycle. */
348 if (phi_pred->copy[p - 1] == NULL && get_irn_op(phi_pred->irn) == op_Phi) {
350 phi->copy[p] = phi->irn;
352 phi->copy[p] = phi_pred->irn;
354 phi->copy[p] = phi_pred->copy[p - 1];
357 /* The predecessors of phi are loop invariant and the copies von phi
358 must be phi it self.*/
359 for(p = 0; p < unroll_factor - 1; ++p)
360 phi->copy[p] = phi->irn;
364 * Decide if the loop head must be copied. A head with important nodes
367 * @param l_n A set, where the node of the loop are saved.
368 * @param info Contains information about the induction variable.
370 * @return non-zero if the loop head must be copied
373 loop_head_nodes(set *l_n, induct_var_info *info)
377 ir_node *loop_head = get_loop_node(info->l_itervar_phi, 0);
379 for (value = set_first(l_n); value != NULL; value = set_next(l_n))
380 if (is_no_Block(value->irn) && get_nodes_block(value->irn) == loop_head)
381 /* If the loop head contains just this nodes, than must not be copy. */
382 switch (get_irn_opcode(value->irn)) {
399 /** Copy all loop nodes.
401 * @param l_n Contains all nodes of the loop.
402 * @param info Contains the loop information.
403 * @param unroll_factor A integer 2 <= unroll_factor <= 4.
406 copy_loop_body(set *l_n, induct_var_info *info, int unroll_factor)
409 copies_t *value, *info_op, *phi, *loop_h = NULL, key, *value_block;
410 ir_node *proj_b, *cond, *proj_1, *proj_0, *loop_head;
411 proj_b = get_irn_out(info->cmp, 0);
412 cond = get_irn_out(proj_b, 0);
413 proj_0 = get_irn_out(cond, 0);
414 proj_1 = get_irn_out(cond, 1);
416 loop_head = get_loop_node(info->l_itervar_phi, 0);
417 /* I will create some nodes and need the optimization to
419 opt = get_optimize();
422 for (value = set_first(l_n); value != NULL; value = set_next(l_n)) {
423 if(value->irn == loop_head)
425 else if (is_Phi_in_loop_head(value->irn, loop_head))
427 else if (copy_loop_head){
428 if(value->irn == proj_0){
429 for (i = 0; i < unroll_factor - 1; i++)
430 /* In the copies of the loop head we replace the cmp branche with a jmp node.
431 This is just for "for" loops."do" loops are handled in function
433 value->copy[i] = new_r_Jmp(current_ir_graph, get_nodes_block(value->irn));
434 }else if(value->irn != proj_b && value->irn != cond &&
435 value->irn != proj_1)
436 /* The loop head must be copied. */
437 for (i = 0; i < unroll_factor - 1; i++){
438 copy_irn_to_irg(value->irn, current_ir_graph);
439 value->copy[i] = get_irn_link(value->irn);
442 /* The loop head and its nodes must not be copied. */
443 if((value->irn->op == op_Block &&
444 value->irn != loop_head) ||
445 (value->irn->op != op_Block &&
446 get_nodes_block(value->irn) != loop_head)) {
447 for (i = 0; i<unroll_factor -1; i++) {
448 copy_irn_to_irg(value->irn, current_ir_graph);
449 value->copy[i] = get_irn_link(value->irn);
455 /* Treat the loop head block */
456 new_loop_head(l_n, info, loop_h, unroll_factor, copy_loop_head);
457 /* I have created the nodes and I set the optimization
461 /* Similarly treat the Phis in the loop head block. info->op is the node
462 along the backedges. */
464 info_op = set_find( l_n, &key, sizeof(key), HASH_PTR(key.irn));
465 assert(info_op->irn == get_Phi_pred(info->itervar_phi, info->op_pred_pos));
466 for (i = 0; i < get_irn_n_outs(loop_head); ++i) {
467 ir_node *phi = get_irn_out(loop_head, i);
470 copies_t *phi_pred, *phi_op;
472 key.irn = get_Phi_pred(phi, info->op_pred_pos); // info->op;
473 phi_pred = set_find(l_n, &key, sizeof(key), HASH_PTR(key.irn));
475 phi_op = set_find(l_n, &key, sizeof(key), HASH_PTR(key.irn));
476 set_Phi_copies(phi_op, phi_pred, unroll_factor);
480 for (value = set_first(l_n); value != NULL; value = set_next(l_n)) {
482 /* Set the predecessors of the copies. */
484 set_preds(l_n, value, info, unroll_factor, NULL);
485 }else if ((value->irn->op != op_Block) && get_nodes_block(value->irn) != loop_head)
486 set_preds(l_n, value, info, unroll_factor, NULL);
488 if (is_Phi_in_loop_head(value->irn, loop_head) &&
489 has_backedges(value->irn))
490 /* Set the backedge of phis in the loop head. */
491 set_phi_backedge(l_n, value, info, unroll_factor);
493 if ((value->irn->op != op_Block) && !is_Phi_in_loop_head(value->irn, loop_head) &&
494 value->copy[0] != NULL ) {
495 ir_node *nodes_block = get_nodes_block(value->irn);
497 if (!copy_loop_head && nodes_block == loop_head)
500 key.irn = nodes_block;
501 value_block = set_find( l_n, &key, sizeof(key), HASH_PTR(key.irn));
502 /* Set the copy of the node in the accordant copy of its block. */
503 for(i = 0; i < unroll_factor - 1; i++){
504 set_nodes_block(value->copy[i], value_block->copy[i]);
508 /* I must repair some control flow edges, when the loop head
510 if (copy_loop_head && !(info->l_itervar_phi->flags & do_loop)){
512 value = set_find( l_n, &key, sizeof(key), HASH_PTR(key.irn));
513 key.irn = get_irn_out(proj_0, 0);
514 info_op = set_find( l_n, &key, sizeof(key), HASH_PTR(key.irn));
515 for (i = 0; i < unroll_factor - 1; i++){
516 set_Block_cfgpred(info_op->copy[i], 0, value->copy[i]);
522 * Returns non-zero if a Proj node from the loop has a predecessor that
523 * can throw an exception.
525 * @param node A Proj node from the loop.
527 * @return non-zero if the predecessor of the Proj node can throw an exception
529 static int is_exception_possible(ir_node *node)
531 ir_node *pred = get_Proj_pred(node);
533 /* only fragile ops can throw an exception */
534 if (! is_fragile_op(pred))
538 * fragile ops that are known NOT to throw
539 * an exception if their pin_state is op_pin_state_floats
541 return get_irn_pinned(pred) != op_pin_state_floats;
545 * If a node from the loop is predecessor of the end block, then the end block must get all copies
546 * of this node as predecessors. This is possible with function calls in the unrolling loop.
548 * @param end_block The end block.
549 * @param loop_head The head of the unrolling loop.
550 * @param l_n Contains all nodes of the loop.
551 * @param loop_endblock_outs The set loop_endblock_outs contains all predecessors
552 * of the end block from the unrolling loop.
553 * @param unroll_factor A integer 2 <= unroll_factor <= 4.
556 new_end_block(ir_node *end_block, ir_node *loop_head, set *l_n, set *loop_endblock_outs, int unroll_factor)
558 copies_t key, *value;
559 int set_el, new_preds, all_new_preds, i, q;
560 int old_preds = get_Block_n_cfgpreds(end_block); /* All old predecessors of the end block. */
563 for (i = 0; i < old_preds; i++) {
564 ir_node *pred = get_Block_cfgpred(end_block, i);
567 value = set_find( l_n, &key, sizeof(key), HASH_PTR(key.irn));
569 /* If a predecessor of the end block is a Proj from the unrolling loop (for function calls) .*/
570 if (get_irn_op(pred) == op_Proj && is_exception_possible(pred) && value != NULL &&
571 !(!copy_loop_head && get_nodes_block(pred) == loop_head))
572 value = set_insert(loop_endblock_outs, &key, sizeof(key), HASH_PTR(key.irn));
575 /* The set loop_endblock_outs contains all predecessors of the end block from the unrolling loop,
576 * set_el the amount of such nodes.
578 set_el = set_count (loop_endblock_outs);
580 /* If the end block haven't such predecessors, we are finished. */
583 new_preds = (unroll_factor - 1) * set_el; /* All new predecessors of the end block */
584 all_new_preds = old_preds + new_preds; /* All predecessors of this block. */
585 all_in = alloca(sizeof(*all_in) * all_new_preds); /* A array with size for all predecessors of this block. */
587 for (i = 0; i < old_preds; i++)
588 all_in[i] = get_Block_cfgpred(end_block, i); /* The old predecessors. */
590 value = set_first(loop_endblock_outs);
592 for (; value != NULL; value = set_next(loop_endblock_outs)) {
593 key.irn = value->irn;
594 value = set_find( l_n, &key, sizeof(key), HASH_PTR(key.irn));
595 for (q = 0; q < unroll_factor - 1 ; q++) {
596 all_in[i++] = value->copy[q]; /* The new predecessors. */
601 /* Replace the old predecessors of the end block wit´h the new ones. */
602 set_irn_in(end_block, all_new_preds, all_in);
605 /** new_after_loop_block
607 * The after loop block must examine the possible exceptions in the loop.
608 * If a (Proj) node from the loop is predecessor of this block, then the
609 * after loop block must have as well all copies of this node as predecessors.
611 * @param l_n Contains all nodes of the loop.
612 * @param block A block after the loop.
613 * @param loop_in A node from the loop, that is predecessor of the end block.
614 * @param unroll_factor An integer 2 <= unroll_factor <= 4.
617 new_after_loop_block (set *l_n, ir_node* block, copies_t *loop_in, int unroll_factor)
619 copies_t key, *value;
620 int i, p, q, s, old_preds, new_preds, all_new_preds ;
623 /* The node from the unrolling loop must be a Proj. */
624 if (loop_in->irn->op != op_Proj) return;
626 old_preds = get_Block_n_cfgpreds(block); /* All old predecessors of this block. */
627 new_preds = old_preds * (unroll_factor - 1); /* All new predecessors of this block. */
628 all_new_preds = old_preds + new_preds; /* All predecessors of this block. */
630 all_in = alloca(sizeof(*all_in) * all_new_preds); /* An array with size for all predecessors of this block. */
632 for (i = 0 ; i < old_preds; i++)
633 all_in[i] = get_Block_cfgpred(block, i); /* The old predecessors. */
636 for (i = 0; i < old_preds; i++){
638 value = set_find( l_n, &key, sizeof(key), HASH_PTR(key.irn));
640 for (s = 0; s < (unroll_factor - 1); s++) {
641 all_in[q++] = value->copy[p++]; /* The new predecessors. */
644 /* Replace the old predecessors of the end block whit the new one. */
645 set_irn_in(block, all_new_preds, all_in);
648 /** new_after_loop_node
650 * An after loop node (phi or call) must examine the possible exceptions in the loop.
651 * If a (Proj) node from the loop is predecessor of this node, then the after loop
652 * node must have as well all copies of this node as predecessors.
654 * @param l_n Contains all nodes of the loop.
655 * @param loop_outs Contains nodes after the loop,that have as predecessor a node from the loop.
656 * @param node A node after the loop.
657 * @param loop_in A node (Proj) from the loop, that is predecessor of *node.
658 * @param unroll_factor An integer 2 <= unroll_factor <= 4.
661 new_after_loop_node(set *l_n, set *loop_outs, ir_node *node, copies_t *loop_in, int unroll_factor)
663 ir_node *pred, *block_pred = NULL, *node_block, *new_phi;
664 int phi = 0, old_preds, new_preds, all_new_preds, p, q, i, s;
665 copies_t key, *value = NULL;
668 old_preds = get_irn_arity(node); /* All old predecessors of this node. */
669 new_preds =old_preds * (unroll_factor - 1); /* All new predecessors of this block. */
670 all_new_preds = old_preds + new_preds; /* All predecessors of this block. */
672 all_in = alloca(sizeof(*all_in) * all_new_preds); /* An array with size for all predecessors of this block. */
674 /* Verification Predecessors, successors and operation of node and loop_in.
675 * loop_in must be a Proj node.
677 if (loop_in->irn->op != op_Proj) return;
678 /* Node must be operation Phi with mode memory or a Call node. */
679 if (get_irn_op(node) == op_Phi &&
680 get_irn_mode(node) == mode_M){
681 /* If node is a Phi node,then must have a Call node as successor. */
682 for (i = 0; i < get_irn_n_outs(node); i++)
683 if (get_irn_op(get_irn_out(node, i)) == op_Call) {
691 /* The predecessor of loop_in must not be a loop invariant. */
692 pred = get_Proj_pred(loop_in->irn);
694 value = set_find( l_n, &key, sizeof(key), HASH_PTR(key.irn));
697 node_block = get_nodes_block(node);
699 /* The block of node must also have a (Proj) predecessor from the unrolling loop. */
700 for (i = 0; i < get_Block_n_cfgpreds(node_block); i++) {
701 block_pred = get_Block_cfgpred(node_block, i);
703 if (get_irn_op(block_pred) == op_Proj) {
704 if (get_Proj_pred(block_pred) == pred)
712 if (! block_pred) return;
714 key.irn = block_pred;
715 value = set_find(l_n, &key, sizeof(key), HASH_PTR(key.irn));
720 new_after_loop_block(l_n, node_block, value, unroll_factor);
722 for (i = 0; i < old_preds; ++i)
723 all_in[i] = get_irn_n(node, i); /* The old predecessors. */
726 for (i = 0; i < old_preds; ++i) {
728 value = set_find( l_n, &key, sizeof(key), HASH_PTR(key.irn));
730 for (s = 0; s < (unroll_factor - 1); ++s) {
731 all_in[q] = value->copy[p]; /* The new predecessors. */
736 /* A new phi node with the new predecessors. */
737 new_phi = new_r_Phi(current_ir_graph, get_nodes_block(node), all_new_preds,all_in,
741 exchange(node, new_phi);
743 for (i = 0; i < get_irn_arity(node); ++i)
744 if (get_irn_n(node, i) == pred)
745 set_irn_n(node, i, new_phi);
748 /* The set loop_outs contains the visited nodes and their blocks. */
750 value = set_insert(loop_outs, &key, sizeof(key), HASH_PTR(key.irn));
751 key.irn = get_nodes_block(node);
752 value = set_insert(loop_outs, &key, sizeof(key), HASH_PTR(key.irn));
756 /* Set the outs of the unrolling loop. All loop outs of a node muss now
757 * point to the last copy of it. Just phi nodes in the loop head and proj
758 * nodes save it outs. The all copies of some Projs have too outs.
760 * @param l_n Contains all nodes of the loop.
761 * @param loop_outs The set contains the visited and changed loop outs.
762 * @param loop_endblock_outs The set loop_endblock_outs contains all predecessors
763 * of the end block from the unrolling loop.
764 * @param info Contains the loop information.
765 * @param unroll_factor A integer 2 <= unroll_factor <= 4.
768 set_loop_outs(set *l_n, set *loop_outs, set *loop_endblock_outs, induct_var_info *info, int unroll_factor)
770 copies_t *value, key;
772 ir_node *loop_head = get_loop_node(info->l_itervar_phi, 0);
773 ir_node *end_block = get_irg_end_block(current_ir_graph);
775 for (value = set_first(l_n); value != NULL; value = set_next(l_n)){
776 if(get_irn_node_nr(value->irn) == 35047)
778 if (! is_Phi_in_loop_head(value->irn, loop_head) &&
779 (get_irn_opcode(value->irn) == iro_Proj && value->copy[0] != NULL))
780 for (i = 0; i < get_irn_n_outs(value->irn); ++i) {
781 key.irn = get_irn_out(value->irn, i);
783 /* Search for loop outs. */
784 if (set_find( l_n, &key, sizeof(key), HASH_PTR(key.irn)) == NULL)
785 if ((key.irn->op == op_Block && get_Block_dom_depth(key.irn) >
786 get_Block_dom_depth(loop_head)) ||
787 (key.irn->op != op_Block && get_Block_dom_depth(get_nodes_block(key.irn)) >
788 get_Block_dom_depth(loop_head))) {
790 for (p = 0; p < get_irn_arity(key.irn); p++)
791 if (value->irn == get_irn_n(key.irn, p)) {
792 if (get_irn_op(value->irn) == op_Proj && is_exception_possible(value->irn)) {
793 if (set_find(loop_outs, &key, sizeof(key), HASH_PTR(key.irn)) == NULL) {
794 /* If the loop out is for exceptions in the loop. */
795 if ((get_irn_op(key.irn) == op_Phi && get_irn_mode(key.irn) == mode_M) ||
796 get_irn_op(key.irn) == op_Call)
797 new_after_loop_node(l_n,loop_outs, key.irn, value, unroll_factor);
803 /* Loop outs in the loop head must be not changed.*/
804 if(get_nodes_block(value->irn) != loop_head)
805 set_irn_n(key.irn, p, value->copy[unroll_factor-2]);
810 /* This function searches for loop outs associated with function call in the unrolling loop. */
811 new_end_block (end_block, loop_head, l_n, loop_endblock_outs, unroll_factor);
815 * Unroll the loop body with a factor that must be power of two.
816 * Called from a post walker.
818 * @param n An IR node.
819 * @param env points to a result
821 static void do_loop_unroll(ir_node *n, void *env)
823 int *unroll_done = env;
824 induct_var_info info;
826 set *loop_nodes, *loop_outs, *loop_endblock_outs;
827 ir_node *phi_init, *loop_head;
828 ir_node *backedge_jmp;
829 int l_sons = 0, unroll_factor = 0;
830 tarval *init, *iter_end, *iter_increment,*tarval_null, *tarval_one, *tarval_three, *tarval_two, *diff, *iter_number;
834 info.itervar_phi = n;
836 /* The IR node must be a induction variable. */
837 if (get_irn_op(n) == op_Phi) {
838 if (is_induction_variable (&info) == NULL)
844 /* Brute force limiting of loop body size. */
845 if (get_loop_n_nodes(info.l_itervar_phi) > 2 ) return;
847 /* Only unroll loops that compare against a constant for exiting. */
848 if (info.cmp == NULL) return;
850 /* We only want to unroll innermost loops. */
851 l_sons = get_loop_n_sons(info.l_itervar_phi);
854 /* "do" loops are not implementit gut for this reason
855 at the time we don't unroll them.*/
856 if(info.l_itervar_phi->flags & do_loop)
859 phi_init = get_Phi_pred(info.itervar_phi, info.init_pred_pos);
861 if ((!(info.l_itervar_phi->flags & loop_is_count_loop)) ||
862 (info.l_itervar_phi->flags & loop_is_endless) ||
863 (info.l_itervar_phi->flags & loop_is_dead) ||
864 (info.l_itervar_phi->flags & once))
867 init = info.l_itervar_phi->loop_iter_start;
868 iter_end = info.l_itervar_phi->loop_iter_end;
869 iter_increment = info.l_itervar_phi->loop_iter_increment;
870 tarval_null = get_mode_null(get_tarval_mode(iter_increment));
871 tarval_one = get_mode_one(get_tarval_mode(init));
873 if(tarval_is_double(init) || tarval_is_double(iter_end) || tarval_is_double(iter_increment))
876 if((tarval_is_negative(init) && tarval_is_negative(iter_end)) ||
877 (!tarval_is_negative(init) && !tarval_is_negative(iter_end)) ||
878 (tarval_is_null(init) || tarval_is_null(iter_end)))
879 diff = tarval_abs(tarval_sub(iter_end, init));
881 diff = tarval_add(tarval_abs(iter_end),tarval_abs(init));
883 iter_increment = tarval_abs(iter_increment);
885 if(!(info.l_itervar_phi->flags & do_loop))
886 diff = tarval_add(diff, tarval_one);
887 /* Test for the value of unroll factor. */
888 if (tarval_cmp(tarval_mod(diff,iter_increment), tarval_null) == pn_Cmp_Eq)
889 iter_number = tarval_div(diff, iter_increment);
892 tarval_two = tarval_add(tarval_one, tarval_one);
893 tarval_three = tarval_add(tarval_two,tarval_one);
895 if (tarval_cmp(tarval_mod(iter_number, tarval_three), tarval_null) == pn_Cmp_Eq)
897 else if (tarval_cmp(tarval_mod(iter_number, tarval_two), tarval_null) == pn_Cmp_Eq)
901 if (get_firm_verbosity())
902 printf("\nloop unrolling with factor %d \n", unroll_factor);
904 /* ok, we will do unrolling */
907 /* The unroll factor must be less than 4. */
908 assert(unroll_factor <= MAX_UNROLL);
910 loop_head = (is_natural_loop(&info)) ? get_loop_node(info.l_itervar_phi, 0) : NULL;
912 assert(loop_head != NULL && is_Block(loop_head));
914 /* We assume, the loop head has exactly one backedge. The position of
915 the backedge is in the following variable: */
916 backedge_pos = (is_backedge(loop_head, 0)) ? 0:1;
918 /* A set with the nodes to copy. */
919 loop_nodes = new_set(set_cmp, 8);
920 /* A set with the loop outs for exceptions. */
921 loop_outs = new_set(set_cmp, 8);
923 /* A set containing all predecessors
924 of the end block from the unrolling loop. */
925 loop_endblock_outs = new_set(set_cmp, 8);
926 /* Find all nodes of the unrolling loop. */
927 find_loop_nodes(info.itervar_phi, get_loop_node(info.l_itervar_phi, 0), loop_nodes);
929 /* Decide if the loop head to be copy.*/
930 copy_loop_head = loop_head_nodes(loop_nodes, &info);
932 /* Copy all nodes of the unrolling loop, that muss be copy. */
933 copy_loop_body(loop_nodes, &info, unroll_factor);
935 backedge_jmp = get_Block_cfgpred(loop_head, backedge_pos);
937 /* Set the backedge of the loop head. */
938 for (value = set_first(loop_nodes); value != NULL; value = set_next(loop_nodes)) {
939 if (value->irn == backedge_jmp)
940 set_Block_cfgpred(loop_head, backedge_pos, value->copy[unroll_factor-2]);
942 set_loop_outs(loop_nodes, loop_outs, loop_endblock_outs, &info, unroll_factor);
945 /* Performs loop unrolling for the passed graph. */
946 void optimize_loop_unrolling(ir_graph *irg /* unroll factor, max body size */)
951 if ( !get_opt_loop_unrolling()) return;
953 rem = current_ir_graph;
954 current_ir_graph = irg;
956 /* -- Precompute some information -- */
958 /* Call algorithm that computes the loop information */
959 // construct_backedges(irg);
960 compute_loop_info(irg);
961 /* Call algorithm that computes the backedges */
962 // construct_cf_backedges(irg);
964 /* Call algorithm that computes the dominator trees. */
967 /* Call algorithm that computes the out edges */
968 assure_irg_outs(irg);
970 collect_phiprojs(irg);
972 /* -- Search expressions that can be optimized -- */
973 irg_walk_graph(irg, NULL, do_loop_unroll, &unroll_done);
976 /* unrolling was done, all info is invalid */
977 set_irg_doms_inconsistent(irg);
978 set_irg_outs_inconsistent(irg);
979 set_irg_loopinfo_state(current_ir_graph, loopinfo_cf_inconsistent);
980 set_trouts_inconsistent();
981 set_irg_callee_info_state(irg, irg_callee_info_inconsistent);
984 current_ir_graph = rem;