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 new_bits_set = tarval_rotl(vrp_left->bits_set, get_Const_tarval(right));
182 new_bits_not_set = tarval_rotl(vrp_left->bits_not_set, get_Const_tarval(right));
188 const vrp_attr *vrp_left;
189 const ir_node *right = get_Shl_right(node);
190 vrp_left = get_vrp_attr(get_Shl_left(node));
192 /* We can only compute this if the right value is a constant*/
193 if (is_Const(right)) {
194 new_bits_set = tarval_shl(vrp_left->bits_set, get_Const_tarval(right));
195 new_bits_not_set = tarval_shl(vrp_left->bits_not_set, get_Const_tarval(right));
201 const vrp_attr *vrp_left;
202 const ir_node *right = get_Shr_right(node);
204 vrp_left = get_vrp_attr(get_Shr_left(node));
206 /* We can only compute this if the right value is a constant*/
207 if (is_Const(right)) {
208 new_bits_set = tarval_shr(vrp_left->bits_set, get_Const_tarval(right));
209 new_bits_not_set = tarval_shr(vrp_left->bits_not_set, get_Const_tarval(right));
215 const vrp_attr *vrp_left;
216 const ir_node *right = get_Shrs_right(node);
218 vrp_left = get_vrp_attr(get_Shrs_left(node));
220 /* We can only compute this if the right value is a constant*/
221 if (is_Const(right)) {
222 new_bits_set = tarval_shrs(vrp_left->bits_set, get_Const_tarval(right));
223 new_bits_not_set = tarval_shrs(vrp_left->bits_not_set, get_Const_tarval(right));
229 const vrp_attr *vrp_left, *vrp_right;
231 vrp_left = get_vrp_attr(get_Eor_left(node));
232 vrp_right = get_vrp_attr(get_Eor_right(node));
234 new_bits_set = tarval_or(
235 tarval_and(vrp_left->bits_set, tarval_not(vrp_right->bits_not_set)),
236 tarval_and(tarval_not(vrp_left->bits_not_set), vrp_right->bits_set));
238 new_bits_not_set = tarval_not(tarval_or(
239 tarval_and(vrp_left->bits_set,vrp_right->bits_set),
240 tarval_and(tarval_not(vrp_left->bits_not_set),
241 tarval_not(vrp_right->bits_not_set))));
247 const vrp_attr *vrp_pred = get_vrp_attr(get_Id_pred(node));
248 new_bits_set = vrp_pred->bits_set;
249 new_bits_not_set = vrp_pred->bits_not_set;
250 new_range_top = vrp_pred->range_top;
251 new_range_bottom = vrp_pred->range_bottom;
252 new_range_type = vrp_pred->range_type;
257 const vrp_attr *vrp_pred = get_vrp_attr(get_Not_op(node));
258 new_bits_set = tarval_not(vrp_pred->bits_not_set);
259 new_bits_not_set = tarval_not(vrp_pred->bits_set);
264 const ir_node *pred = get_Conv_op(node);
265 ir_mode *old_mode = get_irn_mode(pred);
266 const vrp_attr *vrp_pred = get_vrp_attr(pred);
270 if (!mode_is_int(old_mode))
273 new_mode = get_irn_mode(node);
275 /* The second and is needed if target type is smaller*/
276 new_bits_not_set = tarval_convert_to(get_mode_all_one(old_mode), new_mode);
277 new_bits_not_set = tarval_and(new_bits_not_set, tarval_convert_to(vrp_pred->bits_not_set, new_mode));
278 new_bits_set = tarval_and(
279 new_bits_not_set, tarval_convert_to(vrp_pred->bits_set, new_mode));
281 /* Matze: TODO, BUGGY, tarval_cmp never returns ir_relation_less_equal */
282 if (tarval_cmp(vrp_pred->range_top, get_mode_max(new_mode)) == ir_relation_less_equal) {
283 vrp->range_top = vrp_pred->range_top;
286 /* Matze: TODO, BUGGY, tarval_cmp never returns ir_relation_greater_equal */
287 if (tarval_cmp(vrp_pred->range_bottom, get_mode_min(new_mode)) == ir_relation_greater_equal) {
288 vrp->range_bottom = vrp_pred->range_bottom;
294 const ir_relation relation = get_Confirm_relation(node);
295 const ir_node *bound = get_Confirm_bound(node);
298 if (relation == ir_relation_less_greater) {
299 /** @todo: Handle non-Const bounds */
300 if (is_Const(bound)) {
301 new_range_type = VRP_ANTIRANGE;
302 new_range_top = get_Const_tarval(bound);
303 new_range_bottom = get_Const_tarval(bound);
305 } else if (relation == ir_relation_less_equal) {
306 if (is_Const(bound)) {
307 new_range_type = VRP_RANGE;
308 new_range_top = get_Const_tarval(bound);
309 new_range_bottom = get_tarval_min(get_irn_mode(node));
316 /* combine all ranges*/
318 int num = get_Phi_n_preds(node);
319 ir_relation relation;
322 const ir_node *pred = get_Phi_pred(node,0);
323 const vrp_attr *vrp_pred = get_vrp_attr(pred);
324 new_range_top = vrp_pred->range_top;
325 new_range_bottom = vrp_pred->range_bottom;
326 new_range_type = vrp_pred->range_type;
327 new_bits_set = vrp_pred->bits_set;
328 new_bits_not_set = vrp_pred->bits_not_set;
332 for (i = 1; i < num; i++) {
333 pred = get_Phi_pred(node, i);
334 vrp_pred = get_vrp_attr(pred);
335 if (new_range_type == VRP_RANGE && vrp_pred->range_type ==
337 relation = tarval_cmp(new_range_top, vrp_pred->range_top);
338 if (relation == ir_relation_less) {
339 new_range_top = vrp_pred->range_top;
341 relation = tarval_cmp(new_range_bottom, vrp_pred->range_bottom);
342 if (relation == ir_relation_greater) {
343 new_range_bottom = vrp_pred->range_bottom;
346 new_range_type = VRP_VARYING;
348 new_bits_set = tarval_and(new_bits_set, vrp_pred->bits_set);
349 new_bits_not_set = tarval_or(new_bits_not_set,
350 vrp_pred->bits_not_set);
356 /* unhandled, therefore never updated */
362 /* TODO: Check, if there can be information derived from any of these:
363 is_Abs(node) is_Alloc(node) is_Anchor(node) is_Borrow(node) is_Bound(node)
364 is_Break(node) is_Builtin(node) is_Call(node)
365 is_Carry(node) is_Cast(node) is_Cmp(node) is_Cond(node)
366 is_CopyB(node) is_Div(node) is_Dummy(node)
367 is_End(node) is_Free(node)
368 is_IJmp(node) is_InstOf(node) is_Jmp(node) is_Load(node) is_Minus(node)
369 is_Mod(node) is_Mul(node) is_Mulh(node) is_Mux(node) is_NoMem(node)
370 is_Pin(node) is_Proj(node)
371 is_Raise(node) is_Return(node) is_Sel(node) is_Start(node) is_Store(node)
372 is_SymConst(node) is_Sync(node) is_Tuple(node)
375 /* @todo: At this place, we check if the mode of the variable changed. A
376 * better place for this might be in the convopt.c file
379 if (new_bits_set != tarval_bad && get_tarval_mode(new_bits_set) != get_tarval_mode(vrp->bits_set)) {
380 vrp->bits_set = tarval_convert_to(vrp->bits_set, get_irn_mode(node));
382 if (new_bits_not_set != tarval_bad && get_tarval_mode(new_bits_not_set) != get_tarval_mode(vrp->bits_not_set)) {
383 vrp->bits_not_set = tarval_convert_to(vrp->bits_not_set, get_irn_mode(node));
386 if (vrp->range_type != VRP_UNDEFINED && new_range_type != VRP_UNDEFINED && get_tarval_mode(new_range_top) != get_tarval_mode(vrp->range_top)) {
387 /* @todo: We might be able to preserve this range information if it
389 vrp->range_type = VRP_VARYING;
392 /* Merge the newly calculated values with those that might already exist*/
393 if (new_bits_set != tarval_bad) {
394 new_bits_set = tarval_or(new_bits_set, vrp->bits_set);
395 if (tarval_cmp(new_bits_set, vrp->bits_set) != ir_relation_equal) {
396 something_changed = 1;
397 vrp->bits_set = new_bits_set;
400 if (new_bits_not_set != tarval_bad) {
401 new_bits_not_set = tarval_and(new_bits_not_set, vrp->bits_not_set);
403 if (tarval_cmp(new_bits_not_set, vrp->bits_not_set) != ir_relation_equal) {
404 something_changed = 1;
405 vrp->bits_not_set = new_bits_not_set;
409 if (vrp->range_type == VRP_UNDEFINED &&
410 new_range_type != VRP_UNDEFINED) {
411 something_changed = 1;
412 vrp->range_type = new_range_type;
413 vrp->range_bottom = new_range_bottom;
414 vrp->range_top = new_range_top;
416 } else if (vrp->range_type == VRP_RANGE) {
417 if (new_range_type == VRP_RANGE) {
418 if (tarval_cmp(vrp->range_bottom, new_range_bottom) == ir_relation_less) {
419 something_changed = 1;
420 vrp->range_bottom = new_range_bottom;
422 if (tarval_cmp(vrp->range_top, new_range_top) == ir_relation_greater) {
423 something_changed = 1;
424 vrp->range_top = new_range_top;
428 if (new_range_type == VRP_ANTIRANGE) {
429 /* if they are overlapping, cut the range.*/
430 /* TODO: Maybe we can preserve more information here*/
431 if (tarval_cmp(vrp->range_bottom, new_range_top) == ir_relation_greater &&
432 tarval_cmp(vrp->range_bottom, new_range_bottom) == ir_relation_greater) {
433 something_changed = 1;
434 vrp->range_bottom = new_range_top;
436 } else if (tarval_cmp(vrp->range_top, new_range_bottom) == ir_relation_greater &&
437 tarval_cmp(vrp->range_top, new_range_top) == ir_relation_less) {
438 something_changed = 1;
439 vrp->range_top = new_range_bottom;
442 /* We can not handle the case where the anti range is in the*/
446 } else if (vrp->range_type == VRP_ANTIRANGE) {
447 if (new_range_type == VRP_ANTIRANGE) {
448 if (tarval_cmp(vrp->range_bottom, new_range_bottom) == ir_relation_greater) {
449 something_changed = 1;
450 vrp->range_bottom = new_range_bottom;
452 if (tarval_cmp(vrp->range_top, new_range_top) == ir_relation_less) {
453 something_changed = 1;
454 vrp->range_top = new_range_top;
458 if (new_range_type == VRP_RANGE) {
459 if (tarval_cmp(vrp->range_bottom, new_range_top) == ir_relation_greater) {
460 something_changed = 1;
461 vrp->range_bottom = new_range_top;
463 if (tarval_cmp(vrp->range_top, new_range_bottom) == ir_relation_less) {
464 something_changed = 1;
465 vrp->range_top = new_range_bottom;
470 assert(tarval_is_null(
471 tarval_and(vrp->bits_set, tarval_not(vrp->bits_not_set))));
472 return something_changed;
475 static void vrp_first_pass(ir_node *n, void *e)
478 vrp_env_t *env = (vrp_env_t*) e;
483 bitset_set(env->visited, get_irn_idx(n));
487 assure_irg_outs(get_current_ir_graph());
488 for (i = get_irn_n_outs(n) - 1; i >=0; --i) {
489 ir_node *succ = get_irn_out(n, i);
490 if (bitset_is_set(env->visited, get_irn_idx(succ))) {
492 waitq_put(env->workqueue, succ);
497 static void *vrp_init_node(ir_phase *phase, const ir_node *n)
502 DBG((dbg, LEVEL_2, "initialized node nr: %d\n", get_irn_node_nr(n)));
503 vrp = (vrp_attr*) phase_alloc(phase, sizeof(vrp_attr));
505 memset(vrp, 0, sizeof(vrp_attr));
506 /* Initialize the vrp information to default */
508 mode = get_irn_mode(n);
510 vrp->range_type = VRP_UNDEFINED;
512 /* TODO: We might be able to optimize space usage if we do not allocate
513 * vrp space for non-int nodes. (currently caught by vrp_update_node)
515 if (mode_is_int(mode)) {
516 /* We are assuming that 0 is always represented as this modes null */
518 vrp->bits_set = get_mode_null(mode);
519 vrp->bits_not_set = get_mode_all_one(mode);
520 vrp->range_bottom = get_tarval_top();
521 vrp->range_top = get_tarval_top();
524 vrp->bits_set = get_tarval_bad();
525 vrp->bits_not_set = get_tarval_bad();
526 vrp->range_bottom = get_tarval_bad();
527 vrp->range_top = get_tarval_bad();
530 /* TODO: We might be able to set better vrp info at this time, if this is
531 * a node which is newly created in an already initialized irg
533 * maybe just call vrp_update_node and if it returns one, iterate over
539 void set_vrp_data(ir_graph *irg)
541 ir_node *succ, *node;
546 FIRM_DBG_REGISTER(dbg, "ir.ana.vrp");
548 assure_irg_outs(irg); /* ensure that out edges are consistent*/
549 phase = irg_get_phase(irg, PHASE_VRP);
551 /* this is our first run */
552 phase = new_phase(irg, vrp_init_node);
553 irg_register_phase(irg, PHASE_VRP, phase);
554 env = (vrp_env_t*) phase_alloc(phase, sizeof(*env));
557 env = (vrp_env_t*) phase->priv;
560 env->workqueue = new_waitq();
562 env->visited = bitset_malloc(get_irg_last_idx(irg));
563 irg_walk_graph(irg, NULL, vrp_first_pass, env);
564 bitset_free(env->visited);
566 /* while there are entries in the worklist, continue*/
567 while (!waitq_empty(env->workqueue)) {
568 node = (ir_node*) waitq_get(env->workqueue);
570 if (vrp_update_node(node)) {
571 /* if something changed, add successors to worklist*/
572 for (i = get_irn_n_outs(node) - 1; i >= 0; --i) {
573 succ = get_irn_out(node, i);
574 waitq_put(env->workqueue, succ);
578 del_waitq(env->workqueue);
581 ir_graph_pass_t *set_vrp_pass(const char *name)
583 return def_graph_pass(name ? name : "set_vrp", set_vrp_data);
586 ir_relation vrp_cmp(const ir_node *left, const ir_node *right)
588 vrp_attr *vrp_left, *vrp_right;
590 vrp_left = vrp_get_info(left);
591 vrp_right = vrp_get_info(right);
593 if (!vrp_left || !vrp_right)
594 return ir_relation_true;
596 if (vrp_left->range_type == VRP_RANGE && vrp_right->range_type == VRP_RANGE) {
597 if (tarval_cmp(vrp_left->range_top, vrp_right->range_bottom) == ir_relation_less) {
598 return ir_relation_less;
600 if (tarval_cmp(vrp_left->range_bottom, vrp_right->range_top) == ir_relation_greater) {
601 return ir_relation_greater;
605 if (!tarval_is_null(tarval_and(vrp_left->bits_set, tarval_not(vrp_right->bits_not_set))) ||
606 !tarval_is_null(tarval_and(tarval_not(vrp_left->bits_not_set), vrp_right->bits_set))) {
607 return ir_relation_less_greater;
610 /* TODO: We can get way more information here*/
611 return ir_relation_true;
614 vrp_attr *vrp_get_info(const ir_node *node)
616 const ir_graph *irg = get_irn_irg(node);
617 const ir_phase *phase = irg_get_phase(irg, PHASE_VRP);
621 /* phase has not yet been initialized */
625 vrp = (vrp_attr*) phase_get_irn_data(phase, node);
626 if (vrp && vrp->valid) {