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, *vrp_right;
175 const ir_node *right = get_Rotl_right(node);
177 vrp_left = get_vrp_attr(get_Rotl_left(node));
178 vrp_right = get_vrp_attr(get_Rotl_right(node));
180 /* We can only compute this if the right value is a constant*/
181 if (is_Const(right)) {
182 ir_tarval *bits_set, *bits_not_set;
183 bits_set = tarval_rotl(vrp_left->bits_set, get_Const_tarval(right));
184 bits_not_set = tarval_rotl(vrp_left->bits_not_set, get_Const_tarval(right));
190 const vrp_attr *vrp_left, *vrp_right;
191 const ir_node *right = get_Shl_right(node);
192 vrp_left = get_vrp_attr(get_Shl_left(node));
193 vrp_right = get_vrp_attr(get_Shl_right(node));
195 /* We can only compute this if the right value is a constant*/
196 if (is_Const(right)) {
197 new_bits_set = tarval_shl(vrp_left->bits_set, get_Const_tarval(right));
198 new_bits_not_set = tarval_shl(vrp_left->bits_not_set, get_Const_tarval(right));
204 const vrp_attr *vrp_left, *vrp_right;
205 const ir_node *right = get_Shr_right(node);
207 vrp_left = get_vrp_attr(get_Shr_left(node));
208 vrp_right = get_vrp_attr(get_Shr_right(node));
210 /* We can only compute this if the right value is a constant*/
211 if (is_Const(right)) {
212 new_bits_set = tarval_shr(vrp_left->bits_set, get_Const_tarval(right));
213 new_bits_not_set = tarval_shr(vrp_left->bits_not_set, get_Const_tarval(right));
219 const vrp_attr *vrp_left, *vrp_right;
220 const ir_node *right = get_Shrs_right(node);
222 vrp_left = get_vrp_attr(get_Shrs_left(node));
223 vrp_right = get_vrp_attr(get_Shrs_right(node));
225 /* We can only compute this if the right value is a constant*/
226 if (is_Const(right)) {
227 new_bits_set = tarval_shrs(vrp_left->bits_set, get_Const_tarval(right));
228 new_bits_not_set = tarval_shrs(vrp_left->bits_not_set, get_Const_tarval(right));
234 const vrp_attr *vrp_left, *vrp_right;
236 vrp_left = get_vrp_attr(get_Eor_left(node));
237 vrp_right = get_vrp_attr(get_Eor_right(node));
239 new_bits_set = tarval_or(
240 tarval_and(vrp_left->bits_set, tarval_not(vrp_right->bits_not_set)),
241 tarval_and(tarval_not(vrp_left->bits_not_set), vrp_right->bits_set));
243 new_bits_not_set = tarval_not(tarval_or(
244 tarval_and(vrp_left->bits_set,vrp_right->bits_set),
245 tarval_and(tarval_not(vrp_left->bits_not_set),
246 tarval_not(vrp_right->bits_not_set))));
252 const vrp_attr *vrp_pred = get_vrp_attr(get_Id_pred(node));
253 new_bits_set = vrp_pred->bits_set;
254 new_bits_not_set = vrp_pred->bits_not_set;
255 new_range_top = vrp_pred->range_top;
256 new_range_bottom = vrp_pred->range_bottom;
257 new_range_type = vrp_pred->range_type;
262 const vrp_attr *vrp_pred = get_vrp_attr(get_Not_op(node));
263 new_bits_set = tarval_not(vrp_pred->bits_not_set);
264 new_bits_not_set = tarval_not(vrp_pred->bits_set);
269 const ir_node *pred = get_Conv_op(node);
270 ir_mode *old_mode = get_irn_mode(pred);
271 const vrp_attr *vrp_pred = get_vrp_attr(pred);
275 if (!mode_is_int(old_mode))
278 new_mode = get_irn_mode(node);
280 /* The second and is needed if target type is smaller*/
281 new_bits_not_set = tarval_convert_to(get_mode_all_one(old_mode), new_mode);
282 new_bits_not_set = tarval_and(new_bits_not_set, tarval_convert_to(vrp_pred->bits_not_set, new_mode));
283 new_bits_set = tarval_and(
284 new_bits_not_set, tarval_convert_to(vrp_pred->bits_set, new_mode));
286 /* Matze: TODO, BUGGY, tarval_cmp never returns ir_relation_less_equal */
287 if (tarval_cmp(vrp_pred->range_top, get_mode_max(new_mode)) == ir_relation_less_equal) {
288 vrp->range_top = vrp_pred->range_top;
291 /* Matze: TODO, BUGGY, tarval_cmp never returns ir_relation_greater_equal */
292 if (tarval_cmp(vrp_pred->range_bottom, get_mode_min(new_mode)) == ir_relation_greater_equal) {
293 vrp->range_bottom = vrp_pred->range_bottom;
299 const ir_relation relation = get_Confirm_relation(node);
300 const ir_node *bound = get_Confirm_bound(node);
303 if (relation == ir_relation_less_greater) {
304 /** @todo: Handle non-Const bounds */
305 if (is_Const(bound)) {
306 new_range_type = VRP_ANTIRANGE;
307 new_range_top = get_Const_tarval(bound);
308 new_range_bottom = get_Const_tarval(bound);
310 } else if (relation == ir_relation_less_equal) {
311 if (is_Const(bound)) {
312 new_range_type = VRP_RANGE;
313 new_range_top = get_Const_tarval(bound);
314 new_range_bottom = get_tarval_min(get_irn_mode(node));
321 /* combine all ranges*/
323 int num = get_Phi_n_preds(node);
324 ir_relation relation;
327 const ir_node *pred = get_Phi_pred(node,0);
328 const vrp_attr *vrp_pred = get_vrp_attr(pred);
329 new_range_top = vrp_pred->range_top;
330 new_range_bottom = vrp_pred->range_bottom;
331 new_range_type = vrp_pred->range_type;
332 new_bits_set = vrp_pred->bits_set;
333 new_bits_not_set = vrp_pred->bits_not_set;
337 for (i = 1; i < num; i++) {
338 pred = get_Phi_pred(node, i);
339 vrp_pred = get_vrp_attr(pred);
340 if (new_range_type == VRP_RANGE && vrp_pred->range_type ==
342 relation = tarval_cmp(new_range_top, vrp_pred->range_top);
343 if (relation == ir_relation_less) {
344 new_range_top = vrp_pred->range_top;
346 relation = tarval_cmp(new_range_bottom, vrp_pred->range_bottom);
347 if (relation == ir_relation_greater) {
348 new_range_bottom = vrp_pred->range_bottom;
351 new_range_type = VRP_VARYING;
353 new_bits_set = tarval_and(new_bits_set, vrp_pred->bits_set);
354 new_bits_not_set = tarval_or(new_bits_not_set,
355 vrp_pred->bits_not_set);
361 /* unhandled, therefore never updated */
367 /* TODO: Check, if there can be information derived from any of these:
368 is_Abs(node) is_Alloc(node) is_Anchor(node) is_Borrow(node) is_Bound(node)
369 is_Break(node) is_Builtin(node) is_Call(node)
370 is_Carry(node) is_Cast(node) is_Cmp(node) is_Cond(node)
371 is_CopyB(node) is_Div(node) is_Dummy(node)
372 is_End(node) is_Free(node)
373 is_IJmp(node) is_InstOf(node) is_Jmp(node) is_Load(node) is_Minus(node)
374 is_Mod(node) is_Mul(node) is_Mulh(node) is_Mux(node) is_NoMem(node)
375 is_Pin(node) is_Proj(node)
376 is_Raise(node) is_Return(node) is_Sel(node) is_Start(node) is_Store(node)
377 is_SymConst(node) is_Sync(node) is_Tuple(node)
380 /* @todo: At this place, we check if the mode of the variable changed. A
381 * better place for this might be in the convopt.c file
384 if (new_bits_set != tarval_bad && get_tarval_mode(new_bits_set) != get_tarval_mode(vrp->bits_set)) {
385 vrp->bits_set = tarval_convert_to(vrp->bits_set, get_irn_mode(node));
387 if (new_bits_not_set != tarval_bad && get_tarval_mode(new_bits_not_set) != get_tarval_mode(vrp->bits_not_set)) {
388 vrp->bits_not_set = tarval_convert_to(vrp->bits_not_set, get_irn_mode(node));
391 if (vrp->range_type != VRP_UNDEFINED && new_range_type != VRP_UNDEFINED && get_tarval_mode(new_range_top) != get_tarval_mode(vrp->range_top)) {
392 /* @todo: We might be able to preserve this range information if it
394 vrp->range_type = VRP_VARYING;
397 /* Merge the newly calculated values with those that might already exist*/
398 if (new_bits_set != tarval_bad) {
399 new_bits_set = tarval_or(new_bits_set, vrp->bits_set);
400 if (tarval_cmp(new_bits_set, vrp->bits_set) != ir_relation_equal) {
401 something_changed = 1;
402 vrp->bits_set = new_bits_set;
405 if (new_bits_not_set != tarval_bad) {
406 new_bits_not_set = tarval_and(new_bits_not_set, vrp->bits_not_set);
408 if (tarval_cmp(new_bits_not_set, vrp->bits_not_set) != ir_relation_equal) {
409 something_changed = 1;
410 vrp->bits_not_set = new_bits_not_set;
414 if (vrp->range_type == VRP_UNDEFINED &&
415 new_range_type != VRP_UNDEFINED) {
416 something_changed = 1;
417 vrp->range_type = new_range_type;
418 vrp->range_bottom = new_range_bottom;
419 vrp->range_top = new_range_top;
421 } else if (vrp->range_type == VRP_RANGE) {
422 if (new_range_type == VRP_RANGE) {
423 if (tarval_cmp(vrp->range_bottom, new_range_bottom) == ir_relation_less) {
424 something_changed = 1;
425 vrp->range_bottom = new_range_bottom;
427 if (tarval_cmp(vrp->range_top, new_range_top) == ir_relation_greater) {
428 something_changed = 1;
429 vrp->range_top = new_range_top;
433 if (new_range_type == VRP_ANTIRANGE) {
434 /* if they are overlapping, cut the range.*/
435 /* TODO: Maybe we can preserve more information here*/
436 if (tarval_cmp(vrp->range_bottom, new_range_top) == ir_relation_greater &&
437 tarval_cmp(vrp->range_bottom, new_range_bottom) == ir_relation_greater) {
438 something_changed = 1;
439 vrp->range_bottom = new_range_top;
441 } else if (tarval_cmp(vrp->range_top, new_range_bottom) == ir_relation_greater &&
442 tarval_cmp(vrp->range_top, new_range_top) == ir_relation_less) {
443 something_changed = 1;
444 vrp->range_top = new_range_bottom;
447 /* We can not handle the case where the anti range is in the*/
451 } else if (vrp->range_type == VRP_ANTIRANGE) {
452 if (new_range_type == VRP_ANTIRANGE) {
453 if (tarval_cmp(vrp->range_bottom, new_range_bottom) == ir_relation_greater) {
454 something_changed = 1;
455 vrp->range_bottom = new_range_bottom;
457 if (tarval_cmp(vrp->range_top, new_range_top) == ir_relation_less) {
458 something_changed = 1;
459 vrp->range_top = new_range_top;
463 if (new_range_type == VRP_RANGE) {
464 if (tarval_cmp(vrp->range_bottom, new_range_top) == ir_relation_greater) {
465 something_changed = 1;
466 vrp->range_bottom = new_range_top;
468 if (tarval_cmp(vrp->range_top, new_range_bottom) == ir_relation_less) {
469 something_changed = 1;
470 vrp->range_top = new_range_bottom;
475 assert(tarval_is_null(
476 tarval_and(vrp->bits_set, tarval_not(vrp->bits_not_set))));
477 return something_changed;
480 static void vrp_first_pass(ir_node *n, void *e)
483 vrp_env_t *env = (vrp_env_t*) e;
488 bitset_set(env->visited, get_irn_idx(n));
492 assure_irg_outs(get_current_ir_graph());
493 for (i = get_irn_n_outs(n) - 1; i >=0; --i) {
494 ir_node *succ = get_irn_out(n, i);
495 if (bitset_is_set(env->visited, get_irn_idx(succ))) {
497 waitq_put(env->workqueue, succ);
502 static void *vrp_init_node(ir_phase *phase, const ir_node *n)
507 DBG((dbg, LEVEL_2, "initialized node nr: %d\n", get_irn_node_nr(n)));
508 vrp = (vrp_attr*) phase_alloc(phase, sizeof(vrp_attr));
510 memset(vrp, 0, sizeof(vrp_attr));
511 /* Initialize the vrp information to default */
513 mode = get_irn_mode(n);
515 vrp->range_type = VRP_UNDEFINED;
517 /* TODO: We might be able to optimize space usage if we do not allocate
518 * vrp space for non-int nodes. (currently caught by vrp_update_node)
520 if (mode_is_int(mode)) {
521 /* We are assuming that 0 is always represented as this modes null */
523 vrp->bits_set = get_mode_null(mode);
524 vrp->bits_not_set = get_mode_all_one(mode);
525 vrp->range_bottom = get_tarval_top();
526 vrp->range_top = get_tarval_top();
529 vrp->bits_set = get_tarval_bad();
530 vrp->bits_not_set = get_tarval_bad();
531 vrp->range_bottom = get_tarval_bad();
532 vrp->range_top = get_tarval_bad();
535 /* TODO: We might be able to set better vrp info at this time, if this is
536 * a node which is newly created in an already initialized irg
538 * maybe just call vrp_update_node and if it returns one, iterate over
544 void set_vrp_data(ir_graph *irg)
546 ir_node *succ, *node;
551 FIRM_DBG_REGISTER(dbg, "ir.ana.vrp");
553 assure_irg_outs(irg); /* ensure that out edges are consistent*/
554 phase = irg_get_phase(irg, PHASE_VRP);
556 /* this is our first run */
557 phase = new_phase(irg, vrp_init_node);
558 irg_register_phase(irg, PHASE_VRP, phase);
559 env = (vrp_env_t*) phase_alloc(phase, sizeof(*env));
562 env = (vrp_env_t*) phase->priv;
565 env->workqueue = new_waitq();
567 env->visited = bitset_malloc(get_irg_last_idx(irg));
568 irg_walk_graph(irg, NULL, vrp_first_pass, env);
569 bitset_free(env->visited);
571 /* while there are entries in the worklist, continue*/
572 while (!waitq_empty(env->workqueue)) {
573 node = (ir_node*) waitq_get(env->workqueue);
575 if (vrp_update_node(node)) {
576 /* if something changed, add successors to worklist*/
577 for (i = get_irn_n_outs(node) - 1; i >=0; --i) {
578 succ = get_irn_out(node, i);
579 waitq_put(env->workqueue, node);
583 del_waitq(env->workqueue);
586 ir_graph_pass_t *set_vrp_pass(const char *name)
588 return def_graph_pass(name ? name : "set_vrp", set_vrp_data);
591 ir_relation vrp_cmp(const ir_node *left, const ir_node *right)
593 vrp_attr *vrp_left, *vrp_right;
595 vrp_left = vrp_get_info(left);
596 vrp_right = vrp_get_info(right);
598 if (!vrp_left || !vrp_right)
599 return ir_relation_true;
601 if (vrp_left->range_type == VRP_RANGE && vrp_right->range_type == VRP_RANGE) {
602 if (tarval_cmp(vrp_left->range_top, vrp_right->range_bottom) == ir_relation_less) {
603 return ir_relation_less;
605 if (tarval_cmp(vrp_left->range_bottom, vrp_right->range_top) == ir_relation_greater) {
606 return ir_relation_greater;
610 if (!tarval_is_null(tarval_and(vrp_left->bits_set, tarval_not(vrp_right->bits_not_set))) ||
611 !tarval_is_null(tarval_and(tarval_not(vrp_left->bits_not_set), vrp_right->bits_set))) {
612 return ir_relation_less_greater;
615 /* TODO: We can get way more information here*/
616 return ir_relation_true;
619 vrp_attr *vrp_get_info(const ir_node *node)
621 const ir_graph *irg = get_irn_irg(node);
622 const ir_phase *phase = irg_get_phase(irg, PHASE_VRP);
626 /* phase has not yet been initialized */
630 vrp = (vrp_attr*) phase_get_irn_data(phase, node);
631 if (vrp && vrp->valid) {