2 * Copyright (C) 1995-2011 University of Karlsruhe. All right reserved.
4 * This file is part of libFirm.
6 * This file may be distributed and/or modified under the terms of the
7 * GNU General Public License version 2 as published by the Free Software
8 * Foundation and appearing in the file LICENSE.GPL included in the
9 * packaging of this file.
11 * Licensees holding valid libFirm Professional Edition licenses may use
12 * this file in accordance with the libFirm Commercial License.
13 * Agreement provided with the Software.
15 * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
16 * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * @author Christian Helmer
23 * @brief loop inversion and loop unrolling
30 #include "iroptimize.h"
49 #include "irbackedge_t.h"
50 #include "irnodemap.h"
53 DEBUG_ONLY(static firm_dbg_module_t *dbg;)
56 * Convenience macro for iterating over every phi node of the given block.
57 * Requires phi list per block.
59 #define for_each_phi(block, phi) \
60 for ((phi) = get_Block_phis( (block) ); (phi) ; (phi) = get_Phi_next((phi)))
62 #define for_each_phi_safe(head, phi, next) \
63 for ((phi) = (head), (next) = (head) ? get_Phi_next((head)) : NULL; \
64 (phi) ; (phi) = (next), (next) = (next) ? get_Phi_next((next)) : NULL)
66 /* Currently processed loop. */
67 static ir_loop *cur_loop;
69 /* Flag for kind of unrolling. */
73 } unrolling_kind_flag;
75 /* Condition for performing visiting a node during copy_walk. */
76 typedef bool walker_condition(const ir_node *);
78 /* Node and position of a predecessor. */
79 typedef struct entry_edge {
85 /* Node info for unrolling. */
86 typedef struct unrolling_node_info {
88 } unrolling_node_info;
90 /* Outs of the nodes head. */
91 static entry_edge *cur_head_outs;
93 /* Information about the loop head */
94 static ir_node *loop_head = NULL;
95 static bool loop_head_valid = true;
97 /* List of all inner loops, that are processed. */
98 static ir_loop **loops;
101 typedef struct loop_stats_t {
105 unsigned too_large_adapted;
106 unsigned cc_limit_reached;
107 unsigned calls_limit;
109 unsigned u_simple_counting_loop;
110 unsigned constant_unroll;
111 unsigned invariant_unroll;
116 static loop_stats_t stats;
118 /* Set stats to sero */
119 static void reset_stats(void)
121 memset(&stats, 0, sizeof(loop_stats_t));
125 static void print_stats(void)
127 DB((dbg, LEVEL_2, "---------------------------------------\n"));
128 DB((dbg, LEVEL_2, "loops : %d\n",stats.loops));
129 DB((dbg, LEVEL_2, "inverted : %d\n",stats.inverted));
130 DB((dbg, LEVEL_2, "too_large : %d\n",stats.too_large));
131 DB((dbg, LEVEL_2, "too_large_adapted : %d\n",stats.too_large_adapted));
132 DB((dbg, LEVEL_2, "cc_limit_reached : %d\n",stats.cc_limit_reached));
133 DB((dbg, LEVEL_2, "calls_limit : %d\n",stats.calls_limit));
134 DB((dbg, LEVEL_2, "u_simple_counting : %d\n",stats.u_simple_counting_loop));
135 DB((dbg, LEVEL_2, "constant_unroll : %d\n",stats.constant_unroll));
136 DB((dbg, LEVEL_2, "invariant_unroll : %d\n",stats.invariant_unroll));
137 DB((dbg, LEVEL_2, "=======================================\n"));
140 /* Commandline parameters */
141 typedef struct loop_opt_params_t {
142 unsigned max_loop_size; /* Maximum number of nodes [nodes]*/
143 int depth_adaption; /* Loop nest depth adaption [percent] */
144 unsigned allowed_calls; /* Number of calls allowed [number] */
145 bool count_phi; /* Count phi nodes */
146 bool count_proj; /* Count projections */
148 unsigned max_cc_size; /* Maximum condition chain size [nodes] */
149 unsigned max_branches;
151 unsigned max_unrolled_loop_size; /* [nodes] */
152 bool allow_const_unrolling;
153 bool allow_invar_unrolling;
154 unsigned invar_unrolling_min_size; /* [nodes] */
158 static loop_opt_params_t opt_params;
160 /* Loop analysis informations */
161 typedef struct loop_info_t {
162 unsigned nodes; /* node count */
163 unsigned ld_st; /* load and store nodes */
164 unsigned branches; /* number of conditions */
165 unsigned calls; /* number of calls */
166 unsigned cf_outs; /* number of cf edges which leave the loop */
167 entry_edge cf_out; /* single loop leaving cf edge */
168 int be_src_pos; /* position of the single own backedge in the head */
171 unsigned cc_size; /* nodes in the condition chain */
174 unsigned max_unroll; /* Number of unrolls satisfying max_loop_size */
175 unsigned exit_cond; /* 1 if condition==true exits the loop. */
176 unsigned latest_value:1; /* 1 if condition is checked against latest counter value */
177 unsigned needs_backedge:1; /* 0 if loop is completely unrolled */
178 unsigned decreasing:1; /* Step operation is_Sub, or step is<0 */
180 /* IV informations of a simple loop */
184 ir_node *iteration_phi;
187 ir_tarval *count_tar; /* Number of loop iterations */
189 ir_node *duff_cond; /* Duff mod */
190 unrolling_kind_flag unroll_kind; /* constant or invariant unrolling */
193 /* Information about the current loop */
194 static loop_info_t loop_info;
196 /* Outs of the condition chain (loop inversion). */
197 static ir_node **cc_blocks;
198 /* df/cf edges with def in the condition chain */
199 static entry_edge *cond_chain_entries;
200 /* Array of df loops found in the condition chain. */
201 static entry_edge *head_df_loop;
202 /* Number of blocks in cc */
203 static unsigned inversion_blocks_in_cc;
206 /* Cf/df edges leaving the loop.
207 * Called entries here, as they are used to enter the loop with walkers. */
208 static entry_edge *loop_entries;
209 /* Number of unrolls to perform */
210 static int unroll_nr;
211 /* Phase is used to keep copies of nodes. */
212 static ir_nodemap map;
213 static struct obstack obst;
215 /* Loop operations. */
216 typedef enum loop_op_t {
222 /* Saves which loop operation to do until after basic tests. */
223 static loop_op_t loop_op;
225 /* Returns the maximum nodes for the given nest depth */
226 static unsigned get_max_nodes_adapted(unsigned depth)
228 double perc = 100.0 + (double)opt_params.depth_adaption;
229 double factor = pow(perc / 100.0, depth);
231 return (int)((double)opt_params.max_loop_size * factor);
234 /* Reset nodes link. For use with a walker. */
235 static void reset_link(ir_node *node, void *env)
238 set_irn_link(node, NULL);
241 /* Returns 0 if the node or block is not in cur_loop. */
242 static bool is_in_loop(const ir_node *node)
244 return get_irn_loop(get_block_const(node)) == cur_loop;
247 /* Returns 0 if the given edge is not a backedge
248 * with its pred in the cur_loop. */
249 static bool is_own_backedge(const ir_node *n, int pos)
251 return is_backedge(n, pos) && is_in_loop(get_irn_n(n, pos));
254 /* Finds loop head and some loop_info as calls or else if necessary. */
255 static void get_loop_info(ir_node *node, void *env)
257 bool node_in_loop = is_in_loop(node);
261 /* collect some loop information */
263 if (is_Phi(node) && opt_params.count_phi)
265 else if (is_Proj(node) && opt_params.count_proj)
267 else if (!is_Confirm(node) && !is_Const(node) && !is_SymConst(node))
270 if (is_Load(node) || is_Store(node))
277 arity = get_irn_arity(node);
278 for (i = 0; i < arity; i++) {
279 ir_node *pred = get_irn_n(node, i);
280 bool pred_in_loop = is_in_loop(pred);
282 if (is_Block(node) && !node_in_loop && pred_in_loop) {
289 loop_info.cf_out = entry;
292 /* Find the loops head/the blocks with cfpred outside of the loop */
293 if (is_Block(node)) {
296 /* Count innerloop branches */
297 foreach_out_edge_kind(node, edge, EDGE_KIND_BLOCK) {
298 ir_node *succ = get_edge_src_irn(edge);
299 if (is_Block(succ) && is_in_loop(succ))
303 ++loop_info.branches;
305 if (node_in_loop && !pred_in_loop && loop_head_valid) {
306 ir_node *cfgpred = get_Block_cfgpred(node, i);
308 if (!is_in_loop(cfgpred)) {
309 DB((dbg, LEVEL_5, "potential head %+F because inloop and pred %+F not inloop\n",
311 /* another head? We do not touch this. */
312 if (loop_head && loop_head != node) {
313 loop_head_valid = false;
323 /* Finds all edges with users outside of the loop
324 * and definition inside the loop. */
325 static void get_loop_entries(ir_node *node, void *env)
327 unsigned node_in_loop, pred_in_loop;
331 arity = get_irn_arity(node);
332 for (i = 0; i < arity; ++i) {
333 ir_node *pred = get_irn_n(node, i);
335 pred_in_loop = is_in_loop(pred);
336 node_in_loop = is_in_loop(node);
338 if (pred_in_loop && !node_in_loop) {
343 ARR_APP1(entry_edge, loop_entries, entry);
349 static ir_node *ssa_second_def;
350 static ir_node *ssa_second_def_block;
353 * Walks the graph bottom up, searching for definitions and creates phis.
355 static ir_node *search_def_and_create_phis(ir_node *block, ir_mode *mode, int first)
359 ir_graph *irg = get_irn_irg(block);
363 DB((dbg, LEVEL_5, "ssa search_def_and_create_phis: block %N\n", block));
365 /* Prevents creation of phi that would be bad anyway.
366 * Dead and bad blocks. */
367 if (get_irn_arity(block) < 1 || is_Bad(block)) {
368 DB((dbg, LEVEL_5, "ssa bad %N\n", block));
369 return new_r_Bad(irg, mode);
372 if (block == ssa_second_def_block && !first) {
373 DB((dbg, LEVEL_5, "ssa found second definition: use second def %N\n", ssa_second_def));
374 return ssa_second_def;
377 /* already processed this block? */
378 if (irn_visited(block)) {
379 ir_node *value = (ir_node *) get_irn_link(block);
380 DB((dbg, LEVEL_5, "ssa already visited: use linked %N\n", value));
384 assert(block != get_irg_start_block(irg));
386 /* a Block with only 1 predecessor needs no Phi */
387 n_cfgpreds = get_Block_n_cfgpreds(block);
388 if (n_cfgpreds == 1) {
389 ir_node *pred_block = get_Block_cfgpred_block(block, 0);
392 DB((dbg, LEVEL_5, "ssa 1 pred: walk pred %N\n", pred_block));
394 value = search_def_and_create_phis(pred_block, mode, 0);
395 set_irn_link(block, value);
396 mark_irn_visited(block);
401 /* create a new Phi */
402 NEW_ARR_A(ir_node*, in, n_cfgpreds);
403 for (i = 0; i < n_cfgpreds; ++i)
404 in[i] = new_r_Dummy(irg, mode);
406 phi = new_r_Phi(block, n_cfgpreds, in, mode);
407 /* Important: always keep block phi list up to date. */
408 add_Block_phi(block, phi);
409 DB((dbg, LEVEL_5, "ssa phi creation: link new phi %N to block %N\n", phi, block));
410 set_irn_link(block, phi);
411 mark_irn_visited(block);
413 /* set Phi predecessors */
414 for (i = 0; i < n_cfgpreds; ++i) {
416 ir_node *pred_block = get_Block_cfgpred_block(block, i);
417 assert(pred_block != NULL);
418 pred_val = search_def_and_create_phis(pred_block, mode, 0);
420 assert(pred_val != NULL);
422 DB((dbg, LEVEL_5, "ssa phi pred:phi %N, pred %N\n", phi, pred_val));
423 set_irn_n(phi, i, pred_val);
431 * Given a set of values this function constructs SSA-form for the users of the
432 * first value (the users are determined through the out-edges of the value).
433 * Works without using the dominance tree.
435 static void construct_ssa(ir_node *orig_block, ir_node *orig_val,
436 ir_node *second_block, ir_node *second_val)
441 assert(orig_block && orig_val && second_block && second_val &&
442 "no parameter of construct_ssa may be NULL");
444 if (orig_val == second_val)
447 irg = get_irn_irg(orig_val);
449 ir_reserve_resources(irg, IR_RESOURCE_IRN_VISITED);
450 inc_irg_visited(irg);
452 mode = get_irn_mode(orig_val);
453 set_irn_link(orig_block, orig_val);
454 mark_irn_visited(orig_block);
456 ssa_second_def_block = second_block;
457 ssa_second_def = second_val;
459 /* Only fix the users of the first, i.e. the original node */
460 foreach_out_edge_safe(orig_val, edge) {
461 ir_node *user = get_edge_src_irn(edge);
462 int j = get_edge_src_pos(edge);
463 ir_node *user_block = get_nodes_block(user);
470 DB((dbg, LEVEL_5, "original user %N\n", user));
473 ir_node *pred_block = get_Block_cfgpred_block(user_block, j);
474 newval = search_def_and_create_phis(pred_block, mode, 1);
476 newval = search_def_and_create_phis(user_block, mode, 1);
478 if (newval != user && !is_Bad(newval))
479 set_irn_n(user, j, newval);
482 ir_free_resources(irg, IR_RESOURCE_IRN_VISITED);
486 /***** Unrolling Helper Functions *****/
488 /* Assign the copy with index nr to node n */
489 static void set_unroll_copy(ir_node *n, int nr, ir_node *cp)
491 unrolling_node_info *info;
492 assert(nr != 0 && "0 reserved");
494 info = ir_nodemap_get(unrolling_node_info, &map, n);
496 ir_node **arr = NEW_ARR_D(ir_node*, &obst, unroll_nr);
497 memset(arr, 0, unroll_nr * sizeof(ir_node*));
499 info = OALLOCZ(&obst, unrolling_node_info);
501 ir_nodemap_insert(&map, n, info);
506 info->copies[nr] = cp;
509 /* Returns a nodes copy if it exists, else NULL. */
510 static ir_node *get_unroll_copy(ir_node *n, int nr)
513 unrolling_node_info *info = ir_nodemap_get(unrolling_node_info, &map, n);
517 cp = info->copies[nr];
522 /***** Inversion Helper Functions *****/
524 /* Sets copy cp of node n. */
525 static void set_inversion_copy(ir_node *n, ir_node *cp)
527 ir_nodemap_insert(&map, n, cp);
530 /* Getter of copy of n for inversion */
531 static ir_node *get_inversion_copy(ir_node *n)
533 ir_node *cp = ir_nodemap_get(ir_node, &map, n);
537 /* Resets block mark for given node. For use with walker */
538 static void reset_block_mark(ir_node *node, void * env)
543 set_Block_mark(node, 0);
546 /* Returns mark of node, or its block if node is not a block.
547 * Used in this context to determine if node is in the condition chain. */
548 static bool is_nodes_block_marked(const ir_node* node)
550 return get_Block_mark(get_block_const(node));
553 /* Extends a nodes ins by node new.
554 * NOTE: This is slow if a node n needs to be extended more than once. */
555 static void extend_irn(ir_node *n, ir_node *newnode, bool new_is_backedge)
558 int arity = get_irn_arity(n);
559 int new_arity = arity + 1;
560 ir_node **ins = XMALLOCN(ir_node*, new_arity);
561 bool *bes = XMALLOCN(bool, new_arity);
564 /* Bes are important!
565 * Another way would be recreating the looptree,
566 * but after that we cannot distinguish already processed loops
567 * from not yet processed ones. */
569 for(i = 0; i < arity; ++i) {
570 bes[i] = is_backedge(n, i);
572 bes[i] = new_is_backedge;
575 for(i = 0; i < arity; ++i) {
576 ins[i] = get_irn_n(n, i);
580 set_irn_in(n, new_arity, ins);
584 for(i = 0; i < new_arity; ++i) {
593 /* Extends a block by a copy of its pred at pos,
594 * fixing also the phis in the same way. */
595 static void extend_ins_by_copy(ir_node *block, int pos)
599 assert(is_Block(block));
601 /* Extend block by copy of definition at pos */
602 ir_node *const pred = get_Block_cfgpred(block, pos);
603 new_in = get_inversion_copy(pred);
604 DB((dbg, LEVEL_5, "Extend block %N by %N cp of %N\n", block, new_in, pred));
605 extend_irn(block, new_in, false);
607 /* Extend block phis by copy of definition at pos */
608 for_each_phi(block, phi) {
611 pred = get_irn_n(phi, pos);
612 cp = get_inversion_copy(pred);
613 /* If the phis in is not in the condition chain (eg. a constant),
614 * there is no copy. */
620 DB((dbg, LEVEL_5, "Extend phi %N by %N cp of %N\n", phi, new_in, pred));
621 extend_irn(phi, new_in, false);
625 /* Returns the number of blocks backedges. With or without alien bes. */
626 static int get_backedge_n(ir_node *block, bool with_alien)
629 int const arity = get_Block_n_cfgpreds(block);
630 for (int i = 0; i < arity; ++i) {
631 ir_node *const pred = get_Block_cfgpred(block, i);
632 if (is_backedge(block, i) && (with_alien || is_in_loop(pred)))
638 /* Returns a raw copy of the given node.
639 * Attributes are kept/set according to the needs of loop inversion. */
640 static ir_node *copy_node(ir_node *node)
645 cp = exact_copy(node);
646 arity = get_irn_arity(node);
648 /* Keep backedge info */
649 for (i = 0; i < arity; ++i) {
650 if (is_backedge(node, i))
655 set_Block_mark(cp, 0);
663 * This walker copies all walked nodes.
664 * If the walk_condition is true for a node, it is copied.
665 * All nodes node_info->copy have to be NULL prior to every walk.
666 * Order of ins is important for later usage.
668 static void copy_walk(ir_node *node, walker_condition *walk_condition,
677 * break condition and cycle resolver, creating temporary node copies
679 if (irn_visited(node)) {
680 /* Here we rely on nodestate's copy being initialized with NULL */
681 DB((dbg, LEVEL_5, "copy_walk: We have already visited %N\n", node));
682 if (get_inversion_copy(node) == NULL) {
683 cp = copy_node(node);
684 set_inversion_copy(node, cp);
686 DB((dbg, LEVEL_5, "The TEMP copy of %N is created %N\n", node, cp));
692 mark_irn_visited(node);
694 if (!is_Block(node)) {
695 ir_node *pred = get_nodes_block(node);
696 if (walk_condition(pred))
697 DB((dbg, LEVEL_5, "walk block %N\n", pred));
698 copy_walk(pred, walk_condition, set_loop);
701 arity = get_irn_arity(node);
703 NEW_ARR_A(ir_node *, cpin, arity);
705 for (i = 0; i < arity; ++i) {
706 ir_node *pred = get_irn_n(node, i);
708 if (walk_condition(pred)) {
709 DB((dbg, LEVEL_5, "walk node %N\n", pred));
710 copy_walk(pred, walk_condition, set_loop);
711 cpin[i] = get_inversion_copy(pred);
712 DB((dbg, LEVEL_5, "copy of %N gets new in %N which is copy of %N\n",
713 node, get_inversion_copy(pred), pred));
719 /* copy node / finalize temp node */
720 if (get_inversion_copy(node) == NULL) {
721 /* No temporary copy existent */
722 cp = copy_node(node);
723 set_inversion_copy(node, cp);
724 DB((dbg, LEVEL_5, "The FINAL copy of %N is CREATED %N\n", node, cp));
726 /* temporary copy is existent but without correct ins */
727 cp = get_inversion_copy(node);
728 DB((dbg, LEVEL_5, "The FINAL copy of %N is EXISTENT %N\n", node, cp));
731 if (!is_Block(node)) {
732 ir_node *cpblock = get_inversion_copy(get_nodes_block(node));
734 set_nodes_block(cp, cpblock );
736 add_Block_phi(cpblock, cp);
739 /* Keeps phi list of temporary node. */
740 set_irn_in(cp, ARR_LEN(cpin), cpin);
744 * This walker copies all walked nodes.
745 * If the walk_condition is true for a node, it is copied.
746 * All nodes node_info->copy have to be NULL prior to every walk.
747 * Order of ins is important for later usage.
748 * Takes copy_index, to phase-link copy at specific index.
750 static void copy_walk_n(ir_node *node, walker_condition *walk_condition,
759 * break condition and cycle resolver, creating temporary node copies
761 if (irn_visited(node)) {
762 /* Here we rely on nodestate's copy being initialized with NULL */
763 DB((dbg, LEVEL_5, "copy_walk: We have already visited %N\n", node));
764 if (get_unroll_copy(node, copy_index) == NULL) {
767 set_unroll_copy(node, copy_index, u);
768 DB((dbg, LEVEL_5, "The TEMP unknown of %N is created %N\n", node, u));
774 mark_irn_visited(node);
776 if (!is_Block(node)) {
777 ir_node *block = get_nodes_block(node);
778 if (walk_condition(block))
779 DB((dbg, LEVEL_5, "walk block %N\n", block));
780 copy_walk_n(block, walk_condition, copy_index);
783 arity = get_irn_arity(node);
784 NEW_ARR_A(ir_node *, cpin, arity);
786 for (i = 0; i < arity; ++i) {
787 ir_node *pred = get_irn_n(node, i);
789 if (walk_condition(pred)) {
790 DB((dbg, LEVEL_5, "walk node %N\n", pred));
791 copy_walk_n(pred, walk_condition, copy_index);
792 cpin[i] = get_unroll_copy(pred, copy_index);
798 /* copy node / finalize temp node */
799 cp = get_unroll_copy(node, copy_index);
800 if (cp == NULL || is_Unknown(cp)) {
801 cp = copy_node(node);
802 set_unroll_copy(node, copy_index, cp);
803 DB((dbg, LEVEL_5, "The FINAL copy of %N is CREATED %N\n", node, cp));
805 /* temporary copy is existent but without correct ins */
806 cp = get_unroll_copy(node, copy_index);
807 DB((dbg, LEVEL_5, "The FINAL copy of %N is EXISTENT %N\n", node, cp));
810 if (!is_Block(node)) {
811 ir_node *cpblock = get_unroll_copy(get_nodes_block(node), copy_index);
813 set_nodes_block(cp, cpblock );
815 add_Block_phi(cpblock, cp);
818 /* Keeps phi list of temporary node. */
819 set_irn_in(cp, ARR_LEN(cpin), cpin);
822 /* Removes alle Blocks with non marked predecessors from the condition chain. */
823 static void unmark_not_allowed_cc_blocks(void)
825 size_t blocks = ARR_LEN(cc_blocks);
828 for(i = 0; i < blocks; ++i) {
829 ir_node *block = cc_blocks[i];
831 /* Head is an exception. */
832 if (block == loop_head)
835 int const arity = get_Block_n_cfgpreds(block);
836 for (int a = 0; a < arity; ++a) {
837 if (!is_nodes_block_marked(get_Block_cfgpred(block, a))) {
838 set_Block_mark(block, 0);
839 --inversion_blocks_in_cc;
840 DB((dbg, LEVEL_5, "Removed %N from cc (blocks in cc %d)\n",
841 block, inversion_blocks_in_cc));
849 /* Unmarks all cc blocks using cc_blocks except head.
850 * TODO: invert head for unrolling? */
851 static void unmark_cc_blocks(void)
853 size_t blocks = ARR_LEN(cc_blocks);
856 for(i = 0; i < blocks; ++i) {
857 ir_node *block = cc_blocks[i];
859 /* TODO Head is an exception. */
860 /*if (block != loop_head)*/
861 set_Block_mark(block, 0);
863 /*inversion_blocks_in_cc = 1;*/
864 inversion_blocks_in_cc = 0;
867 loop_info.cc_size = 0;
871 * Populates head_entries with (node, pred_pos) tuple
872 * whereas the node's pred at pred_pos is in the cc but not the node itself.
873 * Also finds df loops inside the cc.
874 * Head and condition chain blocks have been marked previously.
876 static void get_head_outs(ir_node *node, void *env)
879 int arity = get_irn_arity(node);
882 for (i = 0; i < arity; ++i) {
883 if (!is_nodes_block_marked(node) && is_nodes_block_marked(get_irn_n(node, i))) {
887 /* Saving also predecessor seems redundant, but becomes
888 * necessary when changing position of it, before
889 * dereferencing it.*/
890 entry.pred = get_irn_n(node, i);
891 ARR_APP1(entry_edge, cur_head_outs, entry);
895 arity = get_irn_arity(loop_head);
897 /* Find df loops inside the cc */
898 if (is_Phi(node) && get_nodes_block(node) == loop_head) {
899 for (i = 0; i < arity; ++i) {
900 if (is_own_backedge(loop_head, i)) {
901 if (is_nodes_block_marked(get_irn_n(node, i))) {
905 entry.pred = get_irn_n(node, i);
906 ARR_APP1(entry_edge, head_df_loop, entry);
907 DB((dbg, LEVEL_5, "Found incc assignment node %N @%d is pred %N, graph %N %N\n",
908 node, i, entry.pred, current_ir_graph, get_irg_start_block(current_ir_graph)));
916 * Find condition chains, and add them to be inverted.
917 * A block belongs to the chain if a condition branches out of the loop.
918 * (Some blocks need to be removed once again.)
919 * Returns 1 if the given block belongs to the condition chain.
921 static void find_condition_chain(ir_node *block)
925 bool jmp_only = true;
926 unsigned nodes_n = 0;
928 mark_irn_visited(block);
930 DB((dbg, LEVEL_5, "condition_chains for block %N\n", block));
933 foreach_out_edge_kind(block, edge, EDGE_KIND_NORMAL) {
937 /* Check if node count would exceed maximum cc size.
939 * This is not optimal, as we search depth-first and break here,
940 * continuing with another subtree. */
941 if (loop_info.cc_size + nodes_n > opt_params.max_cc_size) {
942 set_Block_mark(block, 0);
946 /* Check if block only has a jmp instruction. */
947 foreach_out_edge(block, edge) {
948 ir_node *src = get_edge_src_irn(edge);
950 if (!is_Block(src) && !is_Jmp(src)) {
955 /* Check cf outs if one is leaving the loop,
956 * or if this node has a backedge. */
957 foreach_block_succ(block, edge) {
958 ir_node *src = get_edge_src_irn(edge);
959 int pos = get_edge_src_pos(edge);
961 if (!is_in_loop(src))
964 /* Inverting blocks with backedge outs leads to a cf edge
965 * from the inverted head, into the inverted head (skipping the body).
966 * As the body becomes the new loop head,
967 * this would introduce another loop in the existing loop.
968 * This loop inversion cannot cope with this case. */
969 if (is_backedge(src, pos)) {
975 /* We need all predecessors to already belong to the condition chain.
976 * Example of wrong case: * == in cc
987 /* Collect blocks containing only a Jmp.
988 * Do not collect blocks with backedge outs. */
989 if ((jmp_only || mark) && !has_be) {
990 set_Block_mark(block, 1);
991 ++inversion_blocks_in_cc;
992 loop_info.cc_size += nodes_n;
993 DB((dbg, LEVEL_5, "block %N is part of condition chain\n", block));
994 ARR_APP1(ir_node *, cc_blocks, block);
996 set_Block_mark(block, 0);
999 foreach_block_succ(block, edge) {
1000 ir_node *src = get_edge_src_irn( edge );
1002 if (is_in_loop(src) && ! irn_visited(src))
1003 find_condition_chain(src);
1008 * Rewires the copied condition chain. Removes backedges
1009 * as this condition chain is prior to the loop.
1010 * Copy of loop_head must have phi list and old (unfixed) backedge info of the loop head.
1011 * (loop_head is already fixed, we cannot rely on it.)
1013 static void fix_copy_inversion(void)
1018 ir_node *phi, *next;
1019 ir_node *head_cp = get_inversion_copy(loop_head);
1020 ir_graph *irg = get_irn_irg(head_cp);
1021 int arity = get_irn_arity(head_cp);
1022 int backedges = get_backedge_n(head_cp, false);
1023 int new_arity = arity - backedges;
1027 NEW_ARR_A(ir_node *, ins, new_arity);
1030 /* Remove block backedges */
1031 for(i = 0; i < arity; ++i) {
1032 if (!is_backedge(head_cp, i))
1033 ins[pos++] = get_irn_n(head_cp, i);
1036 new_head = new_r_Block(irg, new_arity, ins);
1038 phis = NEW_ARR_F(ir_node *, 0);
1040 for_each_phi_safe(get_Block_phis(head_cp), phi, next) {
1042 NEW_ARR_A(ir_node *, ins, new_arity);
1044 for(i = 0; i < arity; ++i) {
1045 if (!is_backedge(head_cp, i))
1046 ins[pos++] = get_irn_n(phi, i);
1048 new_phi = new_rd_Phi(get_irn_dbg_info(phi),
1049 new_head, new_arity, ins,
1051 ARR_APP1(ir_node *, phis, new_phi);
1055 for_each_phi_safe(get_Block_phis(head_cp), phi, next) {
1056 exchange(phi, phis[pos++]);
1059 exchange(head_cp, new_head);
1065 /* Puts the original condition chain at the end of the loop,
1066 * subsequently to the body.
1067 * Relies on block phi list and correct backedges.
1069 static void fix_head_inversion(void)
1073 ir_node *phi, *next;
1075 ir_graph *irg = get_irn_irg(loop_head);
1076 int arity = get_irn_arity(loop_head);
1077 int backedges = get_backedge_n(loop_head, false);
1078 int new_arity = backedges;
1082 NEW_ARR_A(ir_node *, ins, new_arity);
1085 /* Keep only backedges */
1086 for(i = 0; i < arity; ++i) {
1087 if (is_own_backedge(loop_head, i))
1088 ins[pos++] = get_irn_n(loop_head, i);
1091 new_head = new_r_Block(irg, new_arity, ins);
1093 phis = NEW_ARR_F(ir_node *, 0);
1095 for_each_phi(loop_head, phi) {
1097 DB((dbg, LEVEL_5, "Fixing phi %N of loop head\n", phi));
1099 NEW_ARR_A(ir_node *, ins, new_arity);
1102 for (i = 0; i < arity; ++i) {
1103 ir_node *pred = get_irn_n(phi, i);
1105 if (is_own_backedge(loop_head, i)) {
1106 /* If assignment is in the condition chain,
1107 * we need to create a phi in the new loop head.
1108 * This can only happen for df, not cf. See find_condition_chains. */
1109 /*if (is_nodes_block_marked(pred)) {
1117 new_phi = new_rd_Phi(get_irn_dbg_info(phi),
1118 new_head, new_arity, ins,
1121 ARR_APP1(ir_node *, phis, new_phi);
1123 DB((dbg, LEVEL_5, "fix inverted head should exch %N by %N (pos %d)\n", phi, new_phi, pos ));
1127 for_each_phi_safe(get_Block_phis(loop_head), phi, next) {
1128 DB((dbg, LEVEL_5, "fix inverted exch phi %N by %N\n", phi, phis[pos]));
1129 if (phis[pos] != phi)
1130 exchange(phi, phis[pos++]);
1135 DB((dbg, LEVEL_5, "fix inverted head exch head block %N by %N\n", loop_head, new_head));
1136 exchange(loop_head, new_head);
1139 /* Does the loop inversion. */
1140 static void inversion_walk(ir_graph *irg, entry_edge *head_entries)
1145 * The order of rewiring bottom-up is crucial.
1146 * Any change of the order leads to lost information that would be needed later.
1149 ir_reserve_resources(irg, IR_RESOURCE_IRN_VISITED);
1151 /* 1. clone condition chain */
1152 inc_irg_visited(irg);
1154 for (i = 0; i < ARR_LEN(head_entries); ++i) {
1155 entry_edge entry = head_entries[i];
1156 ir_node *pred = get_irn_n(entry.node, entry.pos);
1158 DB((dbg, LEVEL_5, "\nInit walk block %N\n", pred));
1160 copy_walk(pred, is_nodes_block_marked, cur_loop);
1163 ir_free_resources(irg, IR_RESOURCE_IRN_VISITED);
1165 /* 2. Extends the head control flow successors ins
1166 * with the definitions of the copied head node. */
1167 for (i = 0; i < ARR_LEN(head_entries); ++i) {
1168 entry_edge head_out = head_entries[i];
1170 if (is_Block(head_out.node))
1171 extend_ins_by_copy(head_out.node, head_out.pos);
1174 /* 3. construct_ssa for users of definitions in the condition chain,
1175 * as there is now a second definition. */
1176 for (i = 0; i < ARR_LEN(head_entries); ++i) {
1177 entry_edge head_out = head_entries[i];
1179 /* Ignore keepalives */
1180 if (is_End(head_out.node))
1183 /* Construct ssa for assignments in the condition chain. */
1184 if (!is_Block(head_out.node)) {
1185 ir_node *pred, *cppred, *block, *cpblock;
1187 pred = head_out.pred;
1188 cppred = get_inversion_copy(pred);
1189 block = get_nodes_block(pred);
1190 cpblock = get_nodes_block(cppred);
1191 construct_ssa(block, pred, cpblock, cppred);
1196 * If there is an assignment in the condition chain
1197 * with a user also in the condition chain,
1198 * the dominance frontier is in the new loop head.
1199 * The dataflow loop is completely in the condition chain.
1204 * Phi_cp | | copied condition chain
1208 * Phi* | | new loop head with newly created phi.
1210 * Phi | | original, inverted condition chain
1215 for (i = 0; i < ARR_LEN(head_df_loop); ++i) {
1216 entry_edge head_out = head_df_loop[i];
1218 /* Construct ssa for assignments in the condition chain. */
1219 ir_node *pred, *cppred, *block, *cpblock;
1221 pred = head_out.pred;
1222 cppred = get_inversion_copy(pred);
1223 assert(cppred && pred);
1224 block = get_nodes_block(pred);
1225 cpblock = get_nodes_block(cppred);
1226 construct_ssa(block, pred, cpblock, cppred);
1229 /* 4. Remove the ins which are no backedges from the original condition chain
1230 * as the cc is now subsequent to the body. */
1231 fix_head_inversion();
1233 /* 5. Remove the backedges of the copied condition chain,
1234 * because it is going to be the new 'head' in advance to the loop. */
1235 fix_copy_inversion();
1239 /* Performs loop inversion of cur_loop if possible and reasonable. */
1240 static void loop_inversion(ir_graph *irg)
1243 unsigned max_loop_nodes = opt_params.max_loop_size;
1244 unsigned max_loop_nodes_adapted;
1245 int depth_adaption = opt_params.depth_adaption;
1247 bool do_inversion = true;
1249 /* Depth of 0 is the procedure and 1 a topmost loop. */
1250 loop_depth = get_loop_depth(cur_loop) - 1;
1252 /* Calculating in per mil. */
1253 max_loop_nodes_adapted = get_max_nodes_adapted(loop_depth);
1255 DB((dbg, LEVEL_1, "max_nodes: %d\nmax_nodes_adapted %d at depth of %d (adaption %d)\n",
1256 max_loop_nodes, max_loop_nodes_adapted, loop_depth, depth_adaption));
1258 if (loop_info.nodes == 0)
1261 if (loop_info.nodes > max_loop_nodes) {
1262 /* Only for stats */
1263 DB((dbg, LEVEL_1, "Nodes %d > allowed nodes %d\n",
1264 loop_info.nodes, loop_depth, max_loop_nodes));
1267 /* Adaption might change it */
1270 /* Limit processing to loops smaller than given parameter. */
1271 if (loop_info.nodes > max_loop_nodes_adapted) {
1272 DB((dbg, LEVEL_1, "Nodes %d > allowed nodes (depth %d adapted) %d\n",
1273 loop_info.nodes, loop_depth, max_loop_nodes_adapted));
1274 ++stats.too_large_adapted;
1278 if (loop_info.calls > opt_params.allowed_calls) {
1279 DB((dbg, LEVEL_1, "Calls %d > allowed calls %d\n",
1280 loop_info.calls, opt_params.allowed_calls));
1281 ++stats.calls_limit;
1285 /*inversion_head_node_limit = INT_MAX;*/
1286 ir_reserve_resources(irg, IR_RESOURCE_BLOCK_MARK);
1288 /* Reset block marks.
1289 * We use block marks to flag blocks of the original condition chain. */
1290 irg_walk_graph(irg, reset_block_mark, NULL, NULL);
1292 /*loop_info.blocks = get_loop_n_blocks(cur_loop);*/
1293 cond_chain_entries = NEW_ARR_F(entry_edge, 0);
1294 head_df_loop = NEW_ARR_F(entry_edge, 0);
1296 /*head_inversion_node_count = 0;*/
1297 inversion_blocks_in_cc = 0;
1299 /* Use phase to keep copy of nodes from the condition chain. */
1300 ir_nodemap_init(&map, irg);
1301 obstack_init(&obst);
1303 /* Search for condition chains and temporarily save the blocks in an array. */
1304 cc_blocks = NEW_ARR_F(ir_node *, 0);
1305 inc_irg_visited(irg);
1306 find_condition_chain(loop_head);
1308 unmark_not_allowed_cc_blocks();
1309 DEL_ARR_F(cc_blocks);
1311 /* Condition chain too large.
1312 * Loop should better be small enough to fit into the cache. */
1313 /* TODO Of course, we should take a small enough cc in the first place,
1314 * which is not that simple. (bin packing) */
1315 if (loop_info.cc_size > opt_params.max_cc_size) {
1316 ++stats.cc_limit_reached;
1318 do_inversion = false;
1320 /* Unmark cc blocks except the head.
1321 * Invert head only for possible unrolling. */
1325 /* We also catch endless loops here,
1326 * because they do not have a condition chain. */
1327 if (inversion_blocks_in_cc < 1) {
1328 do_inversion = false;
1330 "Loop contains %d (less than 1) invertible blocks => No Inversion done.\n",
1331 inversion_blocks_in_cc));
1335 cur_head_outs = NEW_ARR_F(entry_edge, 0);
1337 /* Get all edges pointing into the condition chain. */
1338 irg_walk_graph(irg, get_head_outs, NULL, NULL);
1340 /* Do the inversion */
1341 inversion_walk(irg, cur_head_outs);
1343 DEL_ARR_F(cur_head_outs);
1345 /* Duplicated blocks changed doms */
1346 clear_irg_properties(irg, IR_GRAPH_PROPERTY_CONSISTENT_DOMINANCE
1347 | IR_GRAPH_PROPERTY_CONSISTENT_LOOPINFO);
1353 obstack_free(&obst, NULL);
1354 ir_nodemap_destroy(&map);
1355 DEL_ARR_F(cond_chain_entries);
1356 DEL_ARR_F(head_df_loop);
1358 ir_free_resources(irg, IR_RESOURCE_BLOCK_MARK);
1361 /* Fix the original loop_heads ins for invariant unrolling case. */
1362 static void unrolling_fix_loop_head_inv(void)
1366 ir_node *proj = new_Proj(loop_info.duff_cond, mode_X, 0);
1367 ir_node *head_pred = get_irn_n(loop_head, loop_info.be_src_pos);
1368 ir_node *loop_condition = get_unroll_copy(head_pred, unroll_nr - 1);
1370 /* Original loop_heads ins are:
1371 * duff block and the own backedge */
1373 ins[0] = loop_condition;
1375 set_irn_in(loop_head, 2, ins);
1376 DB((dbg, LEVEL_4, "Rewire ins of block loophead %N to pred %N and duffs entry %N \n" , loop_head, ins[0], ins[1]));
1378 for_each_phi(loop_head, phi) {
1379 ir_node *pred = get_irn_n(phi, loop_info.be_src_pos);
1380 /* TODO we think it is a phi, but for Mergesort it is not the case.*/
1382 ir_node *last_pred = get_unroll_copy(pred, unroll_nr - 1);
1385 ins[1] = (ir_node*)get_irn_link(phi);
1386 set_irn_in(phi, 2, ins);
1387 DB((dbg, LEVEL_4, "Rewire ins of loophead phi %N to pred %N and duffs entry %N \n" , phi, ins[0], ins[1]));
1391 /* Removes previously created phis with only 1 in. */
1392 static void correct_phis(ir_node *node, void *env)
1396 if (is_Phi(node) && get_irn_arity(node) == 1) {
1400 in[0] = get_irn_n(node, 0);
1402 exch = new_rd_Phi(get_irn_dbg_info(node),
1403 get_nodes_block(node), 1, in,
1404 get_irn_mode(node));
1406 exchange(node, exch);
1410 /* Unrolling: Rewire floating copies. */
1411 static void place_copies(int copies)
1413 ir_node *loophead = loop_head;
1416 int be_src_pos = loop_info.be_src_pos;
1418 /* Serialize loops by fixing their head ins.
1419 * Processed are the copies.
1420 * The original loop is done after that, to keep backedge infos. */
1421 for (c = 0; c < copies; ++c) {
1422 ir_node *upper = get_unroll_copy(loophead, c);
1423 ir_node *lower = get_unroll_copy(loophead, c + 1);
1425 ir_node *topmost_be_block = get_nodes_block(get_irn_n(loophead, be_src_pos));
1427 /* Important: get the preds first and then their copy. */
1428 ir_node *upper_be_block = get_unroll_copy(topmost_be_block, c);
1429 ir_node *new_jmp = new_r_Jmp(upper_be_block);
1430 DB((dbg, LEVEL_5, " place_copies upper %N lower %N\n", upper, lower));
1432 DB((dbg, LEVEL_5, "topmost be block %N \n", topmost_be_block));
1434 if (loop_info.unroll_kind == constant) {
1437 set_irn_in(lower, 1, ins);
1439 for_each_phi(loophead, phi) {
1440 ir_node *topmost_def = get_irn_n(phi, be_src_pos);
1441 ir_node *upper_def = get_unroll_copy(topmost_def, c);
1442 ir_node *lower_phi = get_unroll_copy(phi, c + 1);
1444 /* It is possible, that the value used
1445 * in the OWN backedge path is NOT defined in this loop. */
1446 if (is_in_loop(topmost_def))
1449 ins[0] = topmost_def;
1451 set_irn_in(lower_phi, 1, ins);
1452 /* Need to replace phis with 1 in later. */
1455 /* Invariant case */
1456 /* Every node has 2 ins. One from the duff blocks
1457 * and one from the previously unrolled loop. */
1459 /* Calculate corresponding projection of mod result for this copy c */
1460 ir_node *proj = new_Proj(loop_info.duff_cond, mode_X, unroll_nr - c - 1);
1461 DB((dbg, LEVEL_4, "New duff proj %N\n" , proj));
1465 set_irn_in(lower, 2, ins);
1466 DB((dbg, LEVEL_4, "Rewire ins of Block %N to pred %N and duffs entry %N \n" , lower, ins[0], ins[1]));
1468 for_each_phi(loophead, phi) {
1469 ir_node *topmost_phi_pred = get_irn_n(phi, be_src_pos);
1470 ir_node *upper_phi_pred;
1474 lower_phi = get_unroll_copy(phi, c + 1);
1475 duff_phi = (ir_node*)get_irn_link(phi);
1476 DB((dbg, LEVEL_4, "DD Link of %N is %N\n" , phi, duff_phi));
1479 if (is_in_loop(topmost_phi_pred)) {
1480 upper_phi_pred = get_unroll_copy(topmost_phi_pred, c);
1482 upper_phi_pred = topmost_phi_pred;
1485 ins[0] = upper_phi_pred;
1487 set_irn_in(lower_phi, 2, ins);
1488 DB((dbg, LEVEL_4, "Rewire ins of %N to pred %N and duffs entry %N \n" , lower_phi, ins[0], ins[1]));
1493 /* Reconnect last copy. */
1494 for (i = 0; i < ARR_LEN(loop_entries); ++i) {
1495 entry_edge edge = loop_entries[i];
1496 /* Last copy is at the bottom */
1497 ir_node *new_pred = get_unroll_copy(edge.pred, copies);
1498 set_irn_n(edge.node, edge.pos, new_pred);
1501 /* Fix original loops head.
1502 * Done in the end, as ins and be info were needed before. */
1503 if (loop_info.unroll_kind == constant) {
1505 ir_node *head_pred = get_irn_n(loop_head, be_src_pos);
1506 ir_node *loop_condition = get_unroll_copy(head_pred, unroll_nr - 1);
1508 set_irn_n(loop_head, loop_info.be_src_pos, loop_condition);
1510 for_each_phi(loop_head, phi) {
1511 ir_node *pred = get_irn_n(phi, be_src_pos);
1514 /* It is possible, that the value used
1515 * in the OWN backedge path is NOT assigned in this loop. */
1516 if (is_in_loop(pred))
1517 last_pred = get_unroll_copy(pred, copies);
1520 set_irn_n(phi, be_src_pos, last_pred);
1524 unrolling_fix_loop_head_inv();
1528 /* Copies the cur_loop several times. */
1529 static void copy_loop(entry_edge *cur_loop_outs, int copies)
1533 ir_reserve_resources(current_ir_graph, IR_RESOURCE_IRN_VISITED);
1535 for (c = 0; c < copies; ++c) {
1538 inc_irg_visited(current_ir_graph);
1540 DB((dbg, LEVEL_5, " ### Copy_loop copy nr: %d ###\n", c));
1541 for (i = 0; i < ARR_LEN(cur_loop_outs); ++i) {
1542 entry_edge entry = cur_loop_outs[i];
1543 ir_node *pred = get_irn_n(entry.node, entry.pos);
1545 copy_walk_n(pred, is_in_loop, c + 1);
1549 ir_free_resources(current_ir_graph, IR_RESOURCE_IRN_VISITED);
1553 /* Creates a new phi from the given phi node omitting own bes,
1554 * using be_block as supplier of backedge informations. */
1555 static ir_node *clone_phis_sans_bes(ir_node *phi, ir_node *be_block, ir_node *dest_block)
1558 int arity = get_irn_arity(phi);
1562 assert(get_irn_arity(phi) == get_irn_arity(be_block));
1563 assert(is_Phi(phi));
1565 ins = NEW_ARR_F(ir_node *, arity);
1566 for (i = 0; i < arity; ++i) {
1567 if (! is_own_backedge(be_block, i)) {
1568 ins[c] = get_irn_n(phi, i);
1573 newphi = new_r_Phi(dest_block, c, ins, get_irn_mode(phi));
1575 set_irn_link(phi, newphi);
1576 DB((dbg, LEVEL_4, "Linking for duffs device %N to %N\n", phi, newphi));
1581 /* Creates a new block from the given block node omitting own bes,
1582 * using be_block as supplier of backedge informations. */
1583 static ir_node *clone_block_sans_bes(ir_node *node, ir_node *be_block)
1585 int arity = get_irn_arity(node);
1589 assert(get_irn_arity(node) == get_irn_arity(be_block));
1590 assert(is_Block(node));
1592 NEW_ARR_A(ir_node *, ins, arity);
1593 for (i = 0; i < arity; ++i) {
1594 if (! is_own_backedge(be_block, i)) {
1595 ins[c] = get_irn_n(node, i);
1600 return new_Block(c, ins);
1603 /* Creates a structure to calculate absolute value of node op.
1604 * Returns mux node with absolute value. */
1605 static ir_node *new_Abs(ir_node *op, ir_mode *mode)
1607 ir_graph *irg = get_irn_irg(op);
1608 ir_node *block = get_nodes_block(op);
1609 ir_node *zero = new_r_Const(irg, get_mode_null(mode));
1610 ir_node *cmp = new_r_Cmp(block, op, zero, ir_relation_less);
1611 ir_node *minus_op = new_r_Minus(block, op, mode);
1612 ir_node *mux = new_r_Mux(block, cmp, op, minus_op, mode);
1618 /* Creates blocks for duffs device, using previously obtained
1619 * informations about the iv.
1621 static void create_duffs_block(void)
1625 ir_node *block1, *count_block, *duff_block;
1626 ir_node *ems, *ems_mod, *ems_div, *ems_mod_proj, *cmp_null,
1627 *ems_mode_cond, *x_true, *x_false, *const_null;
1628 ir_node *true_val, *false_val;
1631 ir_node *duff_mod, *proj, *cond;
1633 ir_node *count, *correction, *unroll_c;
1634 ir_node *cmp_bad_count, *good_count, *bad_count, *count_phi, *bad_count_neg;
1637 mode = get_irn_mode(loop_info.end_val);
1638 const_null = new_Const(get_mode_null(mode));
1641 * 1. Calculate first approach to count.
1642 * Condition: (end - start) % step == 0 */
1643 block1 = clone_block_sans_bes(loop_head, loop_head);
1644 DB((dbg, LEVEL_4, "Duff block 1 %N\n", block1));
1646 /* Create loop entry phis in first duff block
1647 * as it becomes the loops preheader */
1648 for_each_phi(loop_head, phi) {
1649 /* Returns phis pred if phi would have arity 1*/
1650 ir_node *new_phi = clone_phis_sans_bes(phi, loop_head, block1);
1652 DB((dbg, LEVEL_4, "HEAD %N phi %N\n", loop_head, phi));
1653 DB((dbg, LEVEL_4, "BLOCK1 %N phi %N\n", block1, new_phi));
1656 ems = new_r_Sub(block1, loop_info.end_val, loop_info.start_val,
1657 get_irn_mode(loop_info.end_val));
1658 DB((dbg, LEVEL_4, "BLOCK1 sub %N\n", ems));
1661 ems = new_Sub(loop_info.end_val, loop_info.start_val,
1662 get_irn_mode(loop_info.end_val));
1664 DB((dbg, LEVEL_4, "mod ins %N %N\n", ems, loop_info.step));
1665 ems_mod = new_r_Mod(block1,
1670 op_pin_state_pinned);
1671 ems_div = new_r_Div(block1,
1676 op_pin_state_pinned);
1678 DB((dbg, LEVEL_4, "New module node %N\n", ems_mod));
1680 ems_mod_proj = new_r_Proj(ems_mod, mode_Iu, pn_Mod_res);
1681 cmp_null = new_r_Cmp(block1, ems_mod_proj, const_null, ir_relation_less);
1682 ems_mode_cond = new_r_Cond(block1, cmp_null);
1684 /* ems % step == 0 */
1685 x_true = new_r_Proj(ems_mode_cond, mode_X, pn_Cond_true);
1686 /* ems % step != 0 */
1687 x_false = new_r_Proj(ems_mode_cond, mode_X, pn_Cond_false);
1690 * Assures, duffs device receives a valid count.
1692 * decreasing: count < 0
1693 * increasing: count > 0
1698 count_block = new_Block(2, ins);
1699 DB((dbg, LEVEL_4, "Duff block 2 %N\n", count_block));
1702 /* Increase loop-taken-count depending on the loop condition
1703 * uses the latest iv to compare to. */
1704 if (loop_info.latest_value == 1) {
1705 /* ems % step == 0 : +0 */
1706 true_val = new_Const(get_mode_null(mode));
1707 /* ems % step != 0 : +1 */
1708 false_val = new_Const(get_mode_one(mode));
1710 ir_tarval *tv_two = new_tarval_from_long(2, mode);
1711 /* ems % step == 0 : +1 */
1712 true_val = new_Const(get_mode_one(mode));
1713 /* ems % step != 0 : +2 */
1714 false_val = new_Const(tv_two);
1720 correction = new_r_Phi(count_block, 2, ins, mode);
1722 count = new_r_Proj(ems_div, mode, pn_Div_res);
1724 /* (end - start) / step + correction */
1725 count = new_Add(count, correction, mode);
1727 /* We preconditioned the loop to be tail-controlled.
1728 * So, if count is something 'wrong' like 0,
1729 * negative/positive (depending on step direction),
1730 * we may take the loop once (tail-contr.) and leave it
1731 * to the existing condition, to break; */
1733 /* Depending on step direction, we have to check for > or < 0 */
1734 if (loop_info.decreasing == 1) {
1735 cmp_bad_count = new_r_Cmp(count_block, count, const_null,
1738 cmp_bad_count = new_r_Cmp(count_block, count, const_null,
1739 ir_relation_greater);
1742 bad_count_neg = new_r_Cond(count_block, cmp_bad_count);
1743 good_count = new_Proj(bad_count_neg, mode_X, pn_Cond_true);
1744 bad_count = new_Proj(ems_mode_cond, mode_X, pn_Cond_false);
1747 * Contains module to decide which loop to start from. */
1749 ins[0] = good_count;
1751 duff_block = new_Block(2, ins);
1752 DB((dbg, LEVEL_4, "Duff block 3 %N\n", duff_block));
1754 /* Get absolute value */
1755 ins[0] = new_Abs(count, mode);
1756 /* Manually feed the aforementioned count = 1 (bad case)*/
1757 ins[1] = new_Const(get_mode_one(mode));
1758 count_phi = new_r_Phi(duff_block, 2, ins, mode);
1760 unroll_c = new_Const(new_tarval_from_long((long)unroll_nr, mode));
1762 /* count % unroll_nr */
1763 duff_mod = new_r_Mod(duff_block,
1768 op_pin_state_pinned);
1771 proj = new_Proj(duff_mod, mode, pn_Mod_res);
1772 /* condition does NOT create itself in the block of the proj! */
1773 cond = new_r_Cond(duff_block, proj);
1775 loop_info.duff_cond = cond;
1778 /* Returns 1 if given node is not in loop,
1779 * or if it is a phi of the loop head with only loop invariant defs.
1781 static unsigned is_loop_invariant_def(ir_node *node)
1785 if (! is_in_loop(node)) {
1786 DB((dbg, LEVEL_4, "Not in loop %N\n", node));
1787 /* || is_Const(node) || is_SymConst(node)) {*/
1791 /* If this is a phi of the loophead shared by more than 1 loop,
1792 * we need to check if all defs are not in the loop. */
1795 block = get_nodes_block(node);
1797 /* To prevent unexpected situations. */
1798 if (block != loop_head) {
1802 for (i = 0; i < get_irn_arity(node); ++i) {
1803 /* Check if all bes are just loopbacks. */
1804 if (is_own_backedge(block, i) && get_irn_n(node, i) != node)
1807 DB((dbg, LEVEL_4, "invar %N\n", node));
1810 DB((dbg, LEVEL_4, "Not invar %N\n", node));
1815 /* Returns 1 if one pred of node is invariant and the other is not.
1816 * invar_pred and other are set analogously. */
1817 static unsigned get_invariant_pred(ir_node *node, ir_node **invar_pred, ir_node **other)
1819 ir_node *pred0 = get_irn_n(node, 0);
1820 ir_node *pred1 = get_irn_n(node, 1);
1825 if (is_loop_invariant_def(pred0)) {
1826 DB((dbg, LEVEL_4, "pred0 invar %N\n", pred0));
1827 *invar_pred = pred0;
1831 if (is_loop_invariant_def(pred1)) {
1832 DB((dbg, LEVEL_4, "pred1 invar %N\n", pred1));
1834 if (*invar_pred != NULL) {
1835 /* RETURN. We do not want both preds to be invariant. */
1840 *invar_pred = pred1;
1843 DB((dbg, LEVEL_4, "pred1 not invar %N\n", pred1));
1845 if (*invar_pred != NULL)
1852 /* Starts from a phi that may belong to an iv.
1853 * If an add forms a loop with iteration_phi,
1854 * and add uses a constant, 1 is returned
1855 * and 'start' as well as 'add' are sane. */
1856 static unsigned get_start_and_add(ir_node *iteration_phi, unrolling_kind_flag role)
1859 ir_node *found_add = loop_info.add;
1860 int arity = get_irn_arity(iteration_phi);
1862 DB((dbg, LEVEL_4, "Find start and add from %N\n", iteration_phi));
1864 for (i = 0; i < arity; ++i) {
1866 /* Find start_val which needs to be pred of the iteration_phi.
1867 * If start_val already known, sanity check. */
1868 if (!is_backedge(get_nodes_block(loop_info.iteration_phi), i)) {
1869 ir_node *found_start_val = get_irn_n(loop_info.iteration_phi, i);
1871 DB((dbg, LEVEL_4, "found_start_val %N\n", found_start_val));
1873 /* We already found a start_val it has to be always the same. */
1874 if (loop_info.start_val && found_start_val != loop_info.start_val)
1877 if ((role == constant) && !(is_SymConst(found_start_val) || is_Const(found_start_val)))
1879 else if((role == constant) && !(is_loop_invariant_def(found_start_val)))
1882 loop_info.start_val = found_start_val;
1885 /* The phi has to be in the loop head.
1886 * Follow all own backedges. Every value supplied from these preds of the phi
1887 * needs to origin from the same add. */
1888 if (is_own_backedge(get_nodes_block(loop_info.iteration_phi), i)) {
1889 ir_node *new_found = get_irn_n(loop_info.iteration_phi,i);
1891 DB((dbg, LEVEL_4, "is add? %N\n", new_found));
1893 if (! (is_Add(new_found) || is_Sub(new_found)) || (found_add && found_add != new_found))
1896 found_add = new_found;
1900 loop_info.add = found_add;
1906 /* Returns 1 if one pred of node is a const value and the other is not.
1907 * const_pred and other are set analogously. */
1908 static unsigned get_const_pred(ir_node *node, ir_node **const_pred, ir_node **other)
1910 ir_node *pred0 = get_irn_n(node, 0);
1911 ir_node *pred1 = get_irn_n(node, 1);
1913 DB((dbg, LEVEL_4, "Checking for constant pred of %N\n", node));
1918 /*DB((dbg, LEVEL_4, "is %N const\n", pred0));*/
1919 if (is_Const(pred0) || is_SymConst(pred0)) {
1920 *const_pred = pred0;
1924 /*DB((dbg, LEVEL_4, "is %N const\n", pred1));*/
1925 if (is_Const(pred1) || is_SymConst(pred1)) {
1926 if (*const_pred != NULL) {
1927 /* RETURN. We do not want both preds to be constant. */
1932 *const_pred = pred1;
1935 if (*const_pred == NULL)
1941 /* Returns 1 if loop exits within 2 steps of the iv.
1942 * Norm_proj means we do not exit the loop.*/
1943 static unsigned simulate_next(ir_tarval **count_tar,
1944 ir_tarval *stepped, ir_tarval *step_tar, ir_tarval *end_tar,
1945 ir_relation norm_proj)
1949 DB((dbg, LEVEL_4, "Loop taken if (stepped)%ld %s (end)%ld ",
1950 get_tarval_long(stepped),
1951 get_relation_string((norm_proj)),
1952 get_tarval_long(end_tar)));
1953 DB((dbg, LEVEL_4, "comparing latest value %d\n", loop_info.latest_value));
1955 /* If current iv does not stay in the loop,
1956 * this run satisfied the exit condition. */
1957 if (! (tarval_cmp(stepped, end_tar) & norm_proj))
1960 DB((dbg, LEVEL_4, "Result: (stepped)%ld IS %s (end)%ld\n",
1961 get_tarval_long(stepped),
1962 get_relation_string(tarval_cmp(stepped, end_tar)),
1963 get_tarval_long(end_tar)));
1966 if (is_Add(loop_info.add))
1967 next = tarval_add(stepped, step_tar);
1970 next = tarval_sub(stepped, step_tar, get_irn_mode(loop_info.end_val));
1972 DB((dbg, LEVEL_4, "Loop taken if %ld %s %ld ",
1973 get_tarval_long(next),
1974 get_relation_string(norm_proj),
1975 get_tarval_long(end_tar)));
1976 DB((dbg, LEVEL_4, "comparing latest value %d\n", loop_info.latest_value));
1978 /* Increase steps. */
1979 *count_tar = tarval_add(*count_tar, get_tarval_one(get_tarval_mode(*count_tar)));
1981 /* Next has to fail the loop condition, or we will never exit. */
1982 if (! (tarval_cmp(next, end_tar) & norm_proj))
1988 /* Check if loop meets requirements for a 'simple loop':
1989 * - Exactly one cf out
1991 * - Max nodes after unrolling
1995 * Returns Projection of cmp node or NULL; */
1996 static ir_node *is_simple_loop(void)
1999 ir_node *loop_block, *exit_block, *projx, *cond, *cmp;
2001 /* Maximum of one condition, and no endless loops. */
2002 if (loop_info.cf_outs != 1)
2005 DB((dbg, LEVEL_4, "1 loop exit\n"));
2007 /* Calculate maximum unroll_nr keeping node count below limit. */
2008 loop_info.max_unroll = (int)((double)opt_params.max_unrolled_loop_size / (double)loop_info.nodes);
2009 if (loop_info.max_unroll < 2) {
2014 DB((dbg, LEVEL_4, "maximum unroll factor %u, to not exceed node limit \n",
2015 opt_params.max_unrolled_loop_size));
2017 arity = get_irn_arity(loop_head);
2018 /* RETURN if we have more than 1 be. */
2019 /* Get my backedges without alien bes. */
2021 for (i = 0; i < arity; ++i) {
2022 ir_node *pred = get_irn_n(loop_head, i);
2023 if (is_own_backedge(loop_head, i)) {
2025 /* Our simple loops may have only one backedge. */
2028 loop_block = get_nodes_block(pred);
2029 loop_info.be_src_pos = i;
2034 DB((dbg, LEVEL_4, "loop has 1 own backedge.\n"));
2036 exit_block = get_nodes_block(loop_info.cf_out.pred);
2037 /* The loop has to be tail-controlled.
2038 * This can be changed/improved,
2039 * but we would need a duff iv. */
2040 if (exit_block != loop_block)
2043 DB((dbg, LEVEL_4, "tail-controlled loop.\n"));
2045 /* find value on which loop exit depends */
2046 projx = loop_info.cf_out.pred;
2047 cond = get_irn_n(projx, 0);
2048 cmp = get_irn_n(cond, 0);
2053 DB((dbg, LEVEL_5, "projection is %s\n", get_relation_string(get_Cmp_relation(cmp))));
2055 switch(get_Proj_proj(projx)) {
2057 loop_info.exit_cond = 0;
2060 loop_info.exit_cond = 1;
2063 panic("Cond Proj_proj other than true/false");
2066 DB((dbg, LEVEL_4, "Valid Cmp.\n"));
2070 /* Returns 1 if all nodes are mode_Iu or mode_Is. */
2071 static unsigned are_mode_I(ir_node *n1, ir_node* n2, ir_node *n3)
2073 ir_mode *m1 = get_irn_mode(n1);
2074 ir_mode *m2 = get_irn_mode(n2);
2075 ir_mode *m3 = get_irn_mode(n3);
2077 if ((m1 == mode_Iu && m2 == mode_Iu && m3 == mode_Iu) ||
2078 (m1 == mode_Is && m2 == mode_Is && m3 == mode_Is))
2084 /* Checks if cur_loop is a simple tail-controlled counting loop
2085 * with start and end value loop invariant, step constant. */
2086 static unsigned get_unroll_decision_invariant(void)
2089 ir_node *projres, *loop_condition, *iteration_path;
2091 ir_tarval *step_tar;
2095 /* RETURN if loop is not 'simple' */
2096 projres = is_simple_loop();
2097 if (projres == NULL)
2100 /* Use a minimal size for the invariant unrolled loop,
2101 * as duffs device produces overhead */
2102 if (loop_info.nodes < opt_params.invar_unrolling_min_size)
2105 loop_condition = get_irn_n(projres, 0);
2107 success = get_invariant_pred(loop_condition, &loop_info.end_val, &iteration_path);
2108 DB((dbg, LEVEL_4, "pred invar %d\n", success));
2113 DB((dbg, LEVEL_4, "Invariant End_val %N, other %N\n", loop_info.end_val, iteration_path));
2115 /* We may find the add or the phi first.
2116 * Until now we only have end_val. */
2117 if (is_Add(iteration_path) || is_Sub(iteration_path)) {
2119 loop_info.add = iteration_path;
2120 DB((dbg, LEVEL_4, "Case 1: Got add %N (maybe not sane)\n", loop_info.add));
2122 /* Preds of the add should be step and the iteration_phi */
2123 success = get_const_pred(loop_info.add, &loop_info.step, &loop_info.iteration_phi);
2127 DB((dbg, LEVEL_4, "Got step %N\n", loop_info.step));
2129 if (! is_Phi(loop_info.iteration_phi))
2132 DB((dbg, LEVEL_4, "Got phi %N\n", loop_info.iteration_phi));
2135 * Does necessary sanity check of add, if it is already set. */
2136 success = get_start_and_add(loop_info.iteration_phi, invariant);
2140 DB((dbg, LEVEL_4, "Got start A %N\n", loop_info.start_val));
2142 } else if (is_Phi(iteration_path)) {
2143 ir_node *new_iteration_phi;
2145 loop_info.iteration_phi = iteration_path;
2146 DB((dbg, LEVEL_4, "Case 2: Got phi %N\n", loop_info.iteration_phi));
2148 /* Find start_val and add-node.
2149 * Does necessary sanity check of add, if it is already set. */
2150 success = get_start_and_add(loop_info.iteration_phi, invariant);
2154 DB((dbg, LEVEL_4, "Got start B %N\n", loop_info.start_val));
2155 DB((dbg, LEVEL_4, "Got add or sub %N\n", loop_info.add));
2157 success = get_const_pred(loop_info.add, &loop_info.step, &new_iteration_phi);
2161 DB((dbg, LEVEL_4, "Got step (B) %N\n", loop_info.step));
2163 if (loop_info.iteration_phi != new_iteration_phi)
2170 mode = get_irn_mode(loop_info.end_val);
2172 DB((dbg, LEVEL_4, "start %N, end %N, step %N\n",
2173 loop_info.start_val, loop_info.end_val, loop_info.step));
2175 if (mode != mode_Is && mode != mode_Iu)
2178 /* TODO necessary? */
2179 if (!are_mode_I(loop_info.start_val, loop_info.step, loop_info.end_val))
2182 DB((dbg, LEVEL_4, "mode integer\n"));
2184 step_tar = get_Const_tarval(loop_info.step);
2186 if (tarval_is_null(step_tar)) {
2187 /* TODO Might be worth a warning. */
2191 DB((dbg, LEVEL_4, "step is not 0\n"));
2193 create_duffs_block();
2195 return loop_info.max_unroll;
2198 /* Returns unroll factor,
2199 * given maximum unroll factor and number of loop passes. */
2200 static unsigned get_preferred_factor_constant(ir_tarval *count_tar)
2202 ir_tarval *tar_6, *tar_5, *tar_4, *tar_3, *tar_2;
2204 ir_mode *mode = get_irn_mode(loop_info.end_val);
2206 tar_6 = new_tarval_from_long(6, mode);
2207 tar_5 = new_tarval_from_long(5, mode);
2208 tar_4 = new_tarval_from_long(4, mode);
2209 tar_3 = new_tarval_from_long(3, mode);
2210 tar_2 = new_tarval_from_long(2, mode);
2212 /* loop passes % {6, 5, 4, 3, 2} == 0 */
2213 if (tarval_is_null(tarval_mod(count_tar, tar_6)))
2215 else if (tarval_is_null(tarval_mod(count_tar, tar_5)))
2217 else if (tarval_is_null(tarval_mod(count_tar, tar_4)))
2219 else if (tarval_is_null(tarval_mod(count_tar, tar_3)))
2221 else if (tarval_is_null(tarval_mod(count_tar, tar_2)))
2224 /* gcd(max_unroll, count_tar) */
2225 int a = loop_info.max_unroll;
2226 int b = (int)get_tarval_long(count_tar);
2229 DB((dbg, LEVEL_4, "gcd of max_unroll %d and count_tar %d: ", a, b));
2236 DB((dbg, LEVEL_4, "%d\n", a));
2240 DB((dbg, LEVEL_4, "preferred unroll factor %d\n", prefer));
2243 * If our preference is greater than the allowed unroll factor
2244 * we either might reduce the preferred factor and prevent a duffs device block,
2245 * or create a duffs device block, from which in this case (constants only)
2246 * we know the startloop at compiletime.
2247 * The latter yields the following graphs.
2248 * but for code generation we would want to use graph A.
2249 * The graphs are equivalent. So, we can only reduce the preferred factor.
2259 if (prefer <= loop_info.max_unroll)
2264 if (loop_info.max_unroll >= 3)
2266 else if (loop_info.max_unroll >= 2)
2272 if (loop_info.max_unroll >= 2)
2283 /* Check if cur_loop is a simple counting loop.
2284 * Start, step and end are constants.
2285 * TODO The whole constant case should use procedures similar to
2286 * the invariant case, as they are more versatile. */
2288 static unsigned get_unroll_decision_constant(void)
2290 ir_node *cmp, *iteration_path;
2291 unsigned success, is_latest_val;
2292 ir_tarval *start_tar, *end_tar, *step_tar, *diff_tar, *count_tar;
2294 ir_relation proj_proj, norm_proj;
2297 /* RETURN if loop is not 'simple' */
2298 cmp = is_simple_loop();
2302 /* One in of the loop condition needs to be loop invariant. => end_val
2303 * The other in is assigned by an add. => add
2304 * The add uses a loop invariant value => step
2305 * and a phi with a loop invariant start_val and the add node as ins.
2317 success = get_const_pred(cmp, &loop_info.end_val, &iteration_path);
2321 DB((dbg, LEVEL_4, "End_val %N, other %N\n", loop_info.end_val, iteration_path));
2323 /* We may find the add or the phi first.
2324 * Until now we only have end_val. */
2325 if (is_Add(iteration_path) || is_Sub(iteration_path)) {
2327 /* We test against the latest value of the iv. */
2330 loop_info.add = iteration_path;
2331 DB((dbg, LEVEL_4, "Case 2: Got add %N (maybe not sane)\n", loop_info.add));
2333 /* Preds of the add should be step and the iteration_phi */
2334 success = get_const_pred(loop_info.add, &loop_info.step, &loop_info.iteration_phi);
2338 DB((dbg, LEVEL_4, "Got step %N\n", loop_info.step));
2340 if (! is_Phi(loop_info.iteration_phi))
2343 DB((dbg, LEVEL_4, "Got phi %N\n", loop_info.iteration_phi));
2346 * Does necessary sanity check of add, if it is already set. */
2347 success = get_start_and_add(loop_info.iteration_phi, constant);
2351 DB((dbg, LEVEL_4, "Got start %N\n", loop_info.start_val));
2353 } else if (is_Phi(iteration_path)) {
2354 ir_node *new_iteration_phi;
2356 /* We compare with the value the iv had entering this run. */
2359 loop_info.iteration_phi = iteration_path;
2360 DB((dbg, LEVEL_4, "Case 1: Got phi %N \n", loop_info.iteration_phi));
2362 /* Find start_val and add-node.
2363 * Does necessary sanity check of add, if it is already set. */
2364 success = get_start_and_add(loop_info.iteration_phi, constant);
2368 DB((dbg, LEVEL_4, "Got start %N\n", loop_info.start_val));
2369 DB((dbg, LEVEL_4, "Got add or sub %N\n", loop_info.add));
2371 success = get_const_pred(loop_info.add, &loop_info.step, &new_iteration_phi);
2375 DB((dbg, LEVEL_4, "Got step %N\n", loop_info.step));
2377 if (loop_info.iteration_phi != new_iteration_phi)
2385 mode = get_irn_mode(loop_info.end_val);
2387 DB((dbg, LEVEL_4, "start %N, end %N, step %N\n",
2388 loop_info.start_val, loop_info.end_val, loop_info.step));
2390 if (mode != mode_Is && mode != mode_Iu)
2393 /* TODO necessary? */
2394 if (!are_mode_I(loop_info.start_val, loop_info.step, loop_info.end_val))
2397 DB((dbg, LEVEL_4, "mode integer\n"));
2399 end_tar = get_Const_tarval(loop_info.end_val);
2400 start_tar = get_Const_tarval(loop_info.start_val);
2401 step_tar = get_Const_tarval(loop_info.step);
2403 if (tarval_is_null(step_tar))
2404 /* TODO Might be worth a warning. */
2407 DB((dbg, LEVEL_4, "step is not 0\n"));
2409 if ((!tarval_is_negative(step_tar)) ^ (!is_Sub(loop_info.add)))
2410 loop_info.decreasing = 1;
2412 diff_tar = tarval_sub(end_tar, start_tar, mode);
2414 /* We need at least count_tar steps to be close to end_val, maybe more.
2415 * No way, that we have gone too many steps.
2416 * This represents the 'latest value'.
2417 * (If condition checks against latest value, is checked later) */
2418 count_tar = tarval_div(diff_tar, step_tar);
2420 /* Iv will not pass end_val (except overflows).
2421 * Nothing done, as it would yield to no advantage. */
2422 if (tarval_is_negative(count_tar)) {
2423 DB((dbg, LEVEL_4, "Loop is endless or never taken."));
2424 /* TODO Might be worth a warning. */
2428 ++stats.u_simple_counting_loop;
2430 loop_info.latest_value = is_latest_val;
2433 if (! is_simple_counting_loop(&count_tar))
2437 /* stepped can be negative, if step < 0 */
2438 stepped = tarval_mul(count_tar, step_tar);
2440 /* step as close to end_val as possible, */
2441 /* |stepped| <= |end_tar|, and dist(stepped, end_tar) is smaller than a step. */
2442 if (is_Sub(loop_info.add))
2443 stepped = tarval_sub(start_tar, stepped, mode_Is);
2445 stepped = tarval_add(start_tar, stepped);
2447 DB((dbg, LEVEL_4, "stepped to %ld\n", get_tarval_long(stepped)));
2449 proj_proj = get_Cmp_relation(cmp);
2450 /* Assure that norm_proj is the stay-in-loop case. */
2451 if (loop_info.exit_cond == 1)
2452 norm_proj = get_negated_relation(proj_proj);
2454 norm_proj = proj_proj;
2456 DB((dbg, LEVEL_4, "normalized projection %s\n", get_relation_string(norm_proj)));
2457 /* Executed at most once (stay in counting loop if a Eq b) */
2458 if (norm_proj == ir_relation_equal)
2459 /* TODO Might be worth a warning. */
2462 /* calculates next values and increases count_tar according to it */
2463 success = simulate_next(&count_tar, stepped, step_tar, end_tar, norm_proj);
2467 /* We run loop once more, if we compare to the
2468 * not yet in-/decreased iv. */
2469 if (is_latest_val == 0) {
2470 DB((dbg, LEVEL_4, "condition uses not latest iv value\n"));
2471 count_tar = tarval_add(count_tar, get_tarval_one(mode));
2474 DB((dbg, LEVEL_4, "loop taken %ld times\n", get_tarval_long(count_tar)));
2476 /* Assure the loop is taken at least 1 time. */
2477 if (tarval_is_null(count_tar)) {
2478 /* TODO Might be worth a warning. */
2482 loop_info.count_tar = count_tar;
2483 return get_preferred_factor_constant(count_tar);
2489 static void unroll_loop(void)
2492 if (! (loop_info.nodes > 0))
2495 if (loop_info.nodes > opt_params.max_unrolled_loop_size) {
2496 DB((dbg, LEVEL_2, "Nodes %d > allowed nodes %d\n",
2497 loop_info.nodes, opt_params.max_unrolled_loop_size));
2502 if (loop_info.calls > 0) {
2503 DB((dbg, LEVEL_2, "Calls %d > allowed calls 0\n",
2505 ++stats.calls_limit;
2511 /* get_unroll_decision_constant and invariant are completely
2512 * independent for flexibility.
2513 * Some checks may be performed twice. */
2515 /* constant case? */
2516 if (opt_params.allow_const_unrolling)
2517 unroll_nr = get_unroll_decision_constant();
2518 if (unroll_nr > 1) {
2519 loop_info.unroll_kind = constant;
2522 /* invariant case? */
2523 if (opt_params.allow_invar_unrolling)
2524 unroll_nr = get_unroll_decision_invariant();
2526 loop_info.unroll_kind = invariant;
2529 DB((dbg, LEVEL_2, " *** Unrolling %d times ***\n", unroll_nr));
2531 if (unroll_nr > 1) {
2532 loop_entries = NEW_ARR_F(entry_edge, 0);
2535 irg_walk_graph(current_ir_graph, get_loop_entries, NULL, NULL);
2537 if (loop_info.unroll_kind == constant) {
2538 if ((int)get_tarval_long(loop_info.count_tar) == unroll_nr)
2539 loop_info.needs_backedge = 0;
2541 loop_info.needs_backedge = 1;
2543 loop_info.needs_backedge = 1;
2546 /* Use phase to keep copy of nodes from the condition chain. */
2547 ir_nodemap_init(&map, current_ir_graph);
2548 obstack_init(&obst);
2550 /* Copies the loop */
2551 copy_loop(loop_entries, unroll_nr - 1);
2553 /* Line up the floating copies. */
2554 place_copies(unroll_nr - 1);
2556 /* Remove phis with 1 in
2557 * If there were no nested phis, this would not be necessary.
2558 * Avoiding the creation in the first place
2559 * leads to complex special cases. */
2560 irg_walk_graph(current_ir_graph, correct_phis, NULL, NULL);
2562 if (loop_info.unroll_kind == constant)
2563 ++stats.constant_unroll;
2565 ++stats.invariant_unroll;
2567 clear_irg_properties(current_ir_graph, IR_GRAPH_PROPERTY_CONSISTENT_DOMINANCE);
2569 DEL_ARR_F(loop_entries);
2570 obstack_free(&obst, NULL);
2571 ir_nodemap_destroy(&map);
2576 /* Analyzes the loop, and checks if size is within allowed range.
2577 * Decides if loop will be processed. */
2578 static void init_analyze(ir_graph *irg, ir_loop *loop)
2583 loop_head_valid = true;
2585 /* Reset loop info */
2586 memset(&loop_info, 0, sizeof(loop_info_t));
2588 DB((dbg, LEVEL_1, " >>>> current loop %ld <<<\n",
2589 get_loop_loop_nr(loop)));
2591 /* Collect loop informations: head, node counts. */
2592 irg_walk_graph(irg, get_loop_info, NULL, NULL);
2594 /* RETURN if there is no valid head */
2595 if (!loop_head || !loop_head_valid) {
2596 DB((dbg, LEVEL_1, "No valid loop head. Nothing done.\n"));
2599 DB((dbg, LEVEL_1, "Loophead: %N\n", loop_head));
2602 if (loop_info.branches > opt_params.max_branches) {
2603 DB((dbg, LEVEL_1, "Branches %d > allowed branches %d\n",
2604 loop_info.branches, opt_params.max_branches));
2605 ++stats.calls_limit;
2610 case loop_op_inversion:
2611 loop_inversion(irg);
2614 case loop_op_unrolling:
2619 panic("Loop optimization not implemented.");
2621 DB((dbg, LEVEL_1, " <<<< end of loop with node %ld >>>>\n",
2622 get_loop_loop_nr(loop)));
2625 /* Find innermost loops and add them to loops. */
2626 static void find_innermost_loop(ir_loop *loop)
2628 bool had_sons = false;
2629 size_t n_elements = get_loop_n_elements(loop);
2632 for (e = 0; e < n_elements; ++e) {
2633 loop_element element = get_loop_element(loop, e);
2634 if (*element.kind == k_ir_loop) {
2635 find_innermost_loop(element.son);
2641 ARR_APP1(ir_loop*, loops, loop);
2645 static void set_loop_params(void)
2647 opt_params.max_loop_size = 100;
2648 opt_params.depth_adaption = -50;
2649 opt_params.count_phi = true;
2650 opt_params.count_proj = false;
2651 opt_params.allowed_calls = 0;
2653 opt_params.max_cc_size = 5;
2656 opt_params.allow_const_unrolling = true;
2657 opt_params.allow_invar_unrolling = false;
2659 opt_params.invar_unrolling_min_size = 20;
2660 opt_params.max_unrolled_loop_size = 400;
2661 opt_params.max_branches = 9999;
2664 /* Assure preconditions are met and go through all loops. */
2665 void loop_optimization(ir_graph *irg)
2671 assure_irg_properties(irg,
2672 IR_GRAPH_PROPERTY_CONSISTENT_OUT_EDGES
2673 | IR_GRAPH_PROPERTY_CONSISTENT_OUTS
2674 | IR_GRAPH_PROPERTY_CONSISTENT_LOOPINFO);
2678 /* Reset stats for this procedure */
2682 set_current_ir_graph(irg);
2684 ir_reserve_resources(irg, IR_RESOURCE_IRN_LINK | IR_RESOURCE_PHI_LIST);
2685 collect_phiprojs(irg);
2687 loop = get_irg_loop(irg);
2689 loops = NEW_ARR_F(ir_loop *, 0);
2690 /* List all inner loops */
2691 n_elements = get_loop_n_elements(loop);
2692 for (i = 0; i < n_elements; ++i) {
2693 loop_element element = get_loop_element(loop, i);
2694 if (*element.kind != k_ir_loop)
2696 find_innermost_loop(element.son);
2699 /* Set all links to NULL */
2700 irg_walk_graph(irg, reset_link, NULL, NULL);
2702 for (i = 0; i < ARR_LEN(loops); ++i) {
2703 ir_loop *loop = loops[i];
2707 /* Analyze and handle loop */
2708 init_analyze(irg, loop);
2710 /* Copied blocks do not have their phi list yet */
2711 collect_phiprojs(irg);
2713 /* Set links to NULL
2714 * TODO Still necessary? */
2715 irg_walk_graph(irg, reset_link, NULL, NULL);
2721 ir_free_resources(irg, IR_RESOURCE_IRN_LINK | IR_RESOURCE_PHI_LIST);
2723 confirm_irg_properties(irg, IR_GRAPH_PROPERTIES_NONE);
2726 void do_loop_unrolling(ir_graph *irg)
2728 loop_op = loop_op_unrolling;
2729 loop_optimization(irg);
2732 void do_loop_inversion(ir_graph *irg)
2734 loop_op = loop_op_inversion;
2735 loop_optimization(irg);
2738 void do_loop_peeling(ir_graph *irg)
2740 loop_op = loop_op_peeling;
2741 loop_optimization(irg);
2744 ir_graph_pass_t *loop_inversion_pass(const char *name)
2746 return def_graph_pass(name ? name : "loop_inversion", do_loop_inversion);
2749 ir_graph_pass_t *loop_unroll_pass(const char *name)
2751 return def_graph_pass(name ? name : "loop_unroll", do_loop_unrolling);
2754 ir_graph_pass_t *loop_peeling_pass(const char *name)
2756 return def_graph_pass(name ? name : "loop_peeling", do_loop_peeling);
2759 void firm_init_loop_opt(void)
2761 FIRM_DBG_REGISTER(dbg, "firm.opt.loop");