2 * Copyright (C) 1995-2010 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 * @brief analyze graph to provide value range information
30 #include "iroptimize.h"
32 #include "irgraph_t.h"
40 #include "irphase_t.h"
44 DEBUG_ONLY(static firm_dbg_module_t *dbg);
46 typedef struct vrp_env_t {
51 static vrp_attr *get_vrp_attr(const ir_node *node)
53 return (vrp_attr*) get_or_set_irn_phase_info(node, PHASE_VRP);
56 static int vrp_update_node(ir_node *node)
58 ir_tarval *new_bits_set = get_tarval_bad();
59 ir_tarval *new_bits_not_set = get_tarval_bad();
60 ir_tarval *new_range_bottom = get_tarval_bad();
61 ir_tarval *new_range_top = get_tarval_bad();
62 enum range_types new_range_type = VRP_UNDEFINED;
63 int something_changed = 0;
66 if (!mode_is_int(get_irn_mode(node))) {
67 return 0; /* we don't optimize for non-int-nodes*/
70 vrp = get_vrp_attr(node);
72 /* TODO: Check if all predecessors have valid VRP information*/
74 switch (get_irn_opcode(node)) {
76 ir_tarval *tv = get_Const_tarval(node);
78 new_bits_not_set = tv;
79 new_range_bottom = tv;
81 new_range_type = VRP_RANGE;
85 const vrp_attr *vrp_left, *vrp_right;
86 const ir_node *left, *right;
88 left = get_And_left(node);
89 right = get_And_right(node);
90 vrp_left = get_vrp_attr(left);
91 vrp_right = get_vrp_attr(right);
92 new_bits_set = tarval_and(vrp_left->bits_set, vrp_right->bits_set);
93 new_bits_not_set = tarval_and(vrp_left->bits_not_set, vrp_right->bits_not_set);
99 int overflow_top, overflow_bottom;
100 ir_tarval *new_top, *new_bottom;
101 const vrp_attr *vrp_left, *vrp_right;
102 vrp_left = get_vrp_attr(get_Add_left(node));
103 vrp_right = get_vrp_attr(get_Add_right(node));
105 if (vrp_left->range_type == VRP_UNDEFINED || vrp_right->range_type ==
106 VRP_UNDEFINED || vrp_left->range_type == VRP_VARYING ||
107 vrp_right->range_type == VRP_VARYING) {
111 new_top = tarval_add(vrp_left->range_top, vrp_right->range_top);
112 overflow_top = tarval_carry();
113 new_bottom = tarval_add(vrp_left->range_bottom, vrp_right->range_bottom);
114 overflow_bottom = tarval_carry();
116 if (!overflow_top && !overflow_bottom && vrp_left->range_type == VRP_RANGE
117 &&vrp_right->range_type == VRP_RANGE) {
118 new_range_bottom = new_bottom;
119 new_range_top = new_top;
120 new_range_type = VRP_RANGE;
123 if (overflow_top || overflow_bottom) {
124 /* TODO Implement overflow handling*/
125 new_range_type = VRP_UNDEFINED;
131 int overflow_top, overflow_bottom;
132 ir_tarval *new_top, *new_bottom;
133 const vrp_attr *vrp_left, *vrp_right;
134 vrp_left = get_vrp_attr(get_Sub_left(node));
135 vrp_right = get_vrp_attr(get_Sub_right(node));
137 if (vrp_left->range_type == VRP_UNDEFINED || vrp_right->range_type ==
138 VRP_UNDEFINED || vrp_left->range_type == VRP_VARYING ||
139 vrp_right->range_type == VRP_VARYING) {
143 new_top = tarval_sub(vrp_left->range_top, vrp_right->range_top, NULL);
144 overflow_top = tarval_carry();
145 new_bottom = tarval_sub(vrp_left->range_bottom, vrp_right->range_bottom, NULL);
146 overflow_bottom = tarval_carry();
148 if (!overflow_top && !overflow_bottom && vrp_left->range_type == VRP_RANGE
149 &&vrp_right->range_type == VRP_RANGE) {
150 new_range_bottom = new_bottom;
151 new_range_top = new_top;
152 new_range_type = VRP_RANGE;
155 if (overflow_top || overflow_bottom) {
156 /* TODO Implement overflow handling*/
162 const vrp_attr *vrp_left, *vrp_right;
164 vrp_left = get_vrp_attr(get_Or_left(node));
165 vrp_right = get_vrp_attr(get_Or_right(node));
167 new_bits_set = tarval_or(vrp_left->bits_set, vrp_right->bits_set);
168 new_bits_not_set = tarval_or(vrp_left->bits_not_set, vrp_right->bits_not_set);
174 const vrp_attr *vrp_left;
175 const ir_node *right = get_Rotl_right(node);
177 vrp_left = get_vrp_attr(get_Rotl_left(node));
179 /* We can only compute this if the right value is a constant*/
180 if (is_Const(right)) {
181 ir_tarval *bits_set, *bits_not_set;
182 bits_set = tarval_rotl(vrp_left->bits_set, get_Const_tarval(right));
183 bits_not_set = tarval_rotl(vrp_left->bits_not_set, get_Const_tarval(right));
189 const vrp_attr *vrp_left;
190 const ir_node *right = get_Shl_right(node);
191 vrp_left = get_vrp_attr(get_Shl_left(node));
193 /* We can only compute this if the right value is a constant*/
194 if (is_Const(right)) {
195 new_bits_set = tarval_shl(vrp_left->bits_set, get_Const_tarval(right));
196 new_bits_not_set = tarval_shl(vrp_left->bits_not_set, get_Const_tarval(right));
202 const vrp_attr *vrp_left;
203 const ir_node *right = get_Shr_right(node);
205 vrp_left = get_vrp_attr(get_Shr_left(node));
207 /* We can only compute this if the right value is a constant*/
208 if (is_Const(right)) {
209 new_bits_set = tarval_shr(vrp_left->bits_set, get_Const_tarval(right));
210 new_bits_not_set = tarval_shr(vrp_left->bits_not_set, get_Const_tarval(right));
216 const vrp_attr *vrp_left;
217 const ir_node *right = get_Shrs_right(node);
219 vrp_left = get_vrp_attr(get_Shrs_left(node));
221 /* We can only compute this if the right value is a constant*/
222 if (is_Const(right)) {
223 new_bits_set = tarval_shrs(vrp_left->bits_set, get_Const_tarval(right));
224 new_bits_not_set = tarval_shrs(vrp_left->bits_not_set, get_Const_tarval(right));
230 const vrp_attr *vrp_left, *vrp_right;
232 vrp_left = get_vrp_attr(get_Eor_left(node));
233 vrp_right = get_vrp_attr(get_Eor_right(node));
235 new_bits_set = tarval_or(
236 tarval_and(vrp_left->bits_set, tarval_not(vrp_right->bits_not_set)),
237 tarval_and(tarval_not(vrp_left->bits_not_set), vrp_right->bits_set));
239 new_bits_not_set = tarval_not(tarval_or(
240 tarval_and(vrp_left->bits_set,vrp_right->bits_set),
241 tarval_and(tarval_not(vrp_left->bits_not_set),
242 tarval_not(vrp_right->bits_not_set))));
248 const vrp_attr *vrp_pred = get_vrp_attr(get_Id_pred(node));
249 new_bits_set = vrp_pred->bits_set;
250 new_bits_not_set = vrp_pred->bits_not_set;
251 new_range_top = vrp_pred->range_top;
252 new_range_bottom = vrp_pred->range_bottom;
253 new_range_type = vrp_pred->range_type;
258 const vrp_attr *vrp_pred = get_vrp_attr(get_Not_op(node));
259 new_bits_set = tarval_not(vrp_pred->bits_not_set);
260 new_bits_not_set = tarval_not(vrp_pred->bits_set);
265 const ir_node *pred = get_Conv_op(node);
266 ir_mode *old_mode = get_irn_mode(pred);
267 const vrp_attr *vrp_pred = get_vrp_attr(pred);
271 if (!mode_is_int(old_mode))
274 new_mode = get_irn_mode(node);
276 /* The second and is needed if target type is smaller*/
277 new_bits_not_set = tarval_convert_to(get_mode_all_one(old_mode), new_mode);
278 new_bits_not_set = tarval_and(new_bits_not_set, tarval_convert_to(vrp_pred->bits_not_set, new_mode));
279 new_bits_set = tarval_and(
280 new_bits_not_set, tarval_convert_to(vrp_pred->bits_set, new_mode));
282 /* Matze: TODO, BUGGY, tarval_cmp never returns ir_relation_less_equal */
283 if (tarval_cmp(vrp_pred->range_top, get_mode_max(new_mode)) == ir_relation_less_equal) {
284 vrp->range_top = vrp_pred->range_top;
287 /* Matze: TODO, BUGGY, tarval_cmp never returns ir_relation_greater_equal */
288 if (tarval_cmp(vrp_pred->range_bottom, get_mode_min(new_mode)) == ir_relation_greater_equal) {
289 vrp->range_bottom = vrp_pred->range_bottom;
295 const ir_relation relation = get_Confirm_relation(node);
296 const ir_node *bound = get_Confirm_bound(node);
299 if (relation == ir_relation_less_greater) {
300 /** @todo: Handle non-Const bounds */
301 if (is_Const(bound)) {
302 new_range_type = VRP_ANTIRANGE;
303 new_range_top = get_Const_tarval(bound);
304 new_range_bottom = get_Const_tarval(bound);
306 } else if (relation == ir_relation_less_equal) {
307 if (is_Const(bound)) {
308 new_range_type = VRP_RANGE;
309 new_range_top = get_Const_tarval(bound);
310 new_range_bottom = get_tarval_min(get_irn_mode(node));
317 /* combine all ranges*/
319 int num = get_Phi_n_preds(node);
320 ir_relation relation;
323 const ir_node *pred = get_Phi_pred(node,0);
324 const vrp_attr *vrp_pred = get_vrp_attr(pred);
325 new_range_top = vrp_pred->range_top;
326 new_range_bottom = vrp_pred->range_bottom;
327 new_range_type = vrp_pred->range_type;
328 new_bits_set = vrp_pred->bits_set;
329 new_bits_not_set = vrp_pred->bits_not_set;
333 for (i = 1; i < num; i++) {
334 pred = get_Phi_pred(node, i);
335 vrp_pred = get_vrp_attr(pred);
336 if (new_range_type == VRP_RANGE && vrp_pred->range_type ==
338 relation = tarval_cmp(new_range_top, vrp_pred->range_top);
339 if (relation == ir_relation_less) {
340 new_range_top = vrp_pred->range_top;
342 relation = tarval_cmp(new_range_bottom, vrp_pred->range_bottom);
343 if (relation == ir_relation_greater) {
344 new_range_bottom = vrp_pred->range_bottom;
347 new_range_type = VRP_VARYING;
349 new_bits_set = tarval_and(new_bits_set, vrp_pred->bits_set);
350 new_bits_not_set = tarval_or(new_bits_not_set,
351 vrp_pred->bits_not_set);
357 /* unhandled, therefore never updated */
363 /* TODO: Check, if there can be information derived from any of these:
364 is_Abs(node) is_Alloc(node) is_Anchor(node) is_Borrow(node) is_Bound(node)
365 is_Break(node) is_Builtin(node) is_Call(node)
366 is_Carry(node) is_Cast(node) is_Cmp(node) is_Cond(node)
367 is_CopyB(node) is_Div(node) is_Dummy(node)
368 is_End(node) is_Free(node)
369 is_IJmp(node) is_InstOf(node) is_Jmp(node) is_Load(node) is_Minus(node)
370 is_Mod(node) is_Mul(node) is_Mulh(node) is_Mux(node) is_NoMem(node)
371 is_Pin(node) is_Proj(node)
372 is_Raise(node) is_Return(node) is_Sel(node) is_Start(node) is_Store(node)
373 is_SymConst(node) is_Sync(node) is_Tuple(node)
376 /* @todo: At this place, we check if the mode of the variable changed. A
377 * better place for this might be in the convopt.c file
380 if (new_bits_set != tarval_bad && get_tarval_mode(new_bits_set) != get_tarval_mode(vrp->bits_set)) {
381 vrp->bits_set = tarval_convert_to(vrp->bits_set, get_irn_mode(node));
383 if (new_bits_not_set != tarval_bad && get_tarval_mode(new_bits_not_set) != get_tarval_mode(vrp->bits_not_set)) {
384 vrp->bits_not_set = tarval_convert_to(vrp->bits_not_set, get_irn_mode(node));
387 if (vrp->range_type != VRP_UNDEFINED && new_range_type != VRP_UNDEFINED && get_tarval_mode(new_range_top) != get_tarval_mode(vrp->range_top)) {
388 /* @todo: We might be able to preserve this range information if it
390 vrp->range_type = VRP_VARYING;
393 /* Merge the newly calculated values with those that might already exist*/
394 if (new_bits_set != tarval_bad) {
395 new_bits_set = tarval_or(new_bits_set, vrp->bits_set);
396 if (tarval_cmp(new_bits_set, vrp->bits_set) != ir_relation_equal) {
397 something_changed = 1;
398 vrp->bits_set = new_bits_set;
401 if (new_bits_not_set != tarval_bad) {
402 new_bits_not_set = tarval_and(new_bits_not_set, vrp->bits_not_set);
404 if (tarval_cmp(new_bits_not_set, vrp->bits_not_set) != ir_relation_equal) {
405 something_changed = 1;
406 vrp->bits_not_set = new_bits_not_set;
410 if (vrp->range_type == VRP_UNDEFINED &&
411 new_range_type != VRP_UNDEFINED) {
412 something_changed = 1;
413 vrp->range_type = new_range_type;
414 vrp->range_bottom = new_range_bottom;
415 vrp->range_top = new_range_top;
417 } else if (vrp->range_type == VRP_RANGE) {
418 if (new_range_type == VRP_RANGE) {
419 if (tarval_cmp(vrp->range_bottom, new_range_bottom) == ir_relation_less) {
420 something_changed = 1;
421 vrp->range_bottom = new_range_bottom;
423 if (tarval_cmp(vrp->range_top, new_range_top) == ir_relation_greater) {
424 something_changed = 1;
425 vrp->range_top = new_range_top;
429 if (new_range_type == VRP_ANTIRANGE) {
430 /* if they are overlapping, cut the range.*/
431 /* TODO: Maybe we can preserve more information here*/
432 if (tarval_cmp(vrp->range_bottom, new_range_top) == ir_relation_greater &&
433 tarval_cmp(vrp->range_bottom, new_range_bottom) == ir_relation_greater) {
434 something_changed = 1;
435 vrp->range_bottom = new_range_top;
437 } else if (tarval_cmp(vrp->range_top, new_range_bottom) == ir_relation_greater &&
438 tarval_cmp(vrp->range_top, new_range_top) == ir_relation_less) {
439 something_changed = 1;
440 vrp->range_top = new_range_bottom;
443 /* We can not handle the case where the anti range is in the*/
447 } else if (vrp->range_type == VRP_ANTIRANGE) {
448 if (new_range_type == VRP_ANTIRANGE) {
449 if (tarval_cmp(vrp->range_bottom, new_range_bottom) == ir_relation_greater) {
450 something_changed = 1;
451 vrp->range_bottom = new_range_bottom;
453 if (tarval_cmp(vrp->range_top, new_range_top) == ir_relation_less) {
454 something_changed = 1;
455 vrp->range_top = new_range_top;
459 if (new_range_type == VRP_RANGE) {
460 if (tarval_cmp(vrp->range_bottom, new_range_top) == ir_relation_greater) {
461 something_changed = 1;
462 vrp->range_bottom = new_range_top;
464 if (tarval_cmp(vrp->range_top, new_range_bottom) == ir_relation_less) {
465 something_changed = 1;
466 vrp->range_top = new_range_bottom;
471 assert(tarval_is_null(
472 tarval_and(vrp->bits_set, tarval_not(vrp->bits_not_set))));
473 return something_changed;
476 static void vrp_first_pass(ir_node *n, void *e)
479 vrp_env_t *env = (vrp_env_t*) e;
484 bitset_set(env->visited, get_irn_idx(n));
488 assure_irg_outs(get_current_ir_graph());
489 for (i = get_irn_n_outs(n) - 1; i >=0; --i) {
490 ir_node *succ = get_irn_out(n, i);
491 if (bitset_is_set(env->visited, get_irn_idx(succ))) {
493 waitq_put(env->workqueue, succ);
498 static void *vrp_init_node(ir_phase *phase, const ir_node *n)
503 DBG((dbg, LEVEL_2, "initialized node nr: %d\n", get_irn_node_nr(n)));
504 vrp = (vrp_attr*) phase_alloc(phase, sizeof(vrp_attr));
506 memset(vrp, 0, sizeof(vrp_attr));
507 /* Initialize the vrp information to default */
509 mode = get_irn_mode(n);
511 vrp->range_type = VRP_UNDEFINED;
513 /* TODO: We might be able to optimize space usage if we do not allocate
514 * vrp space for non-int nodes. (currently caught by vrp_update_node)
516 if (mode_is_int(mode)) {
517 /* We are assuming that 0 is always represented as this modes null */
519 vrp->bits_set = get_mode_null(mode);
520 vrp->bits_not_set = get_mode_all_one(mode);
521 vrp->range_bottom = get_tarval_top();
522 vrp->range_top = get_tarval_top();
525 vrp->bits_set = get_tarval_bad();
526 vrp->bits_not_set = get_tarval_bad();
527 vrp->range_bottom = get_tarval_bad();
528 vrp->range_top = get_tarval_bad();
531 /* TODO: We might be able to set better vrp info at this time, if this is
532 * a node which is newly created in an already initialized irg
534 * maybe just call vrp_update_node and if it returns one, iterate over
540 void set_vrp_data(ir_graph *irg)
542 ir_node *succ, *node;
547 FIRM_DBG_REGISTER(dbg, "ir.ana.vrp");
549 assure_irg_outs(irg); /* ensure that out edges are consistent*/
550 phase = irg_get_phase(irg, PHASE_VRP);
552 /* this is our first run */
553 phase = new_phase(irg, vrp_init_node);
554 irg_register_phase(irg, PHASE_VRP, phase);
555 env = (vrp_env_t*) phase_alloc(phase, sizeof(*env));
558 env = (vrp_env_t*) phase->priv;
561 env->workqueue = new_waitq();
563 env->visited = bitset_malloc(get_irg_last_idx(irg));
564 irg_walk_graph(irg, NULL, vrp_first_pass, env);
565 bitset_free(env->visited);
567 /* while there are entries in the worklist, continue*/
568 while (!waitq_empty(env->workqueue)) {
569 node = (ir_node*) waitq_get(env->workqueue);
571 if (vrp_update_node(node)) {
572 /* if something changed, add successors to worklist*/
573 for (i = get_irn_n_outs(node) - 1; i >= 0; --i) {
574 succ = get_irn_out(node, i);
575 waitq_put(env->workqueue, node);
579 del_waitq(env->workqueue);
582 ir_graph_pass_t *set_vrp_pass(const char *name)
584 return def_graph_pass(name ? name : "set_vrp", set_vrp_data);
587 ir_relation vrp_cmp(const ir_node *left, const ir_node *right)
589 vrp_attr *vrp_left, *vrp_right;
591 vrp_left = vrp_get_info(left);
592 vrp_right = vrp_get_info(right);
594 if (!vrp_left || !vrp_right)
595 return ir_relation_true;
597 if (vrp_left->range_type == VRP_RANGE && vrp_right->range_type == VRP_RANGE) {
598 if (tarval_cmp(vrp_left->range_top, vrp_right->range_bottom) == ir_relation_less) {
599 return ir_relation_less;
601 if (tarval_cmp(vrp_left->range_bottom, vrp_right->range_top) == ir_relation_greater) {
602 return ir_relation_greater;
606 if (!tarval_is_null(tarval_and(vrp_left->bits_set, tarval_not(vrp_right->bits_not_set))) ||
607 !tarval_is_null(tarval_and(tarval_not(vrp_left->bits_not_set), vrp_right->bits_set))) {
608 return ir_relation_less_greater;
611 /* TODO: We can get way more information here*/
612 return ir_relation_true;
615 vrp_attr *vrp_get_info(const ir_node *node)
617 const ir_graph *irg = get_irn_irg(node);
618 const ir_phase *phase = irg_get_phase(irg, PHASE_VRP);
622 /* phase has not yet been initialized */
626 vrp = (vrp_attr*) phase_get_irn_data(phase, node);
627 if (vrp && vrp->valid) {