1/* Code for GIMPLE range related routines.
2 Copyright (C) 2019-2024 Free Software Foundation, Inc.
3 Contributed by Andrew MacLeod <amacleod@redhat.com>
4 and Aldy Hernandez <aldyh@redhat.com>.
5
6This file is part of GCC.
7
8GCC is free software; you can redistribute it and/or modify
9it under the terms of the GNU General Public License as published by
10the Free Software Foundation; either version 3, or (at your option)
11any later version.
12
13GCC is distributed in the hope that it will be useful,
14but WITHOUT ANY WARRANTY; without even the implied warranty of
15MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16GNU General Public License for more details.
17
18You should have received a copy of the GNU General Public License
19along with GCC; see the file COPYING3. If not see
20<http://www.gnu.org/licenses/>. */
21
22#include "config.h"
23#include "system.h"
24#include "coretypes.h"
25#include "backend.h"
26#include "tree.h"
27#include "gimple.h"
28#include "ssa.h"
29#include "gimple-pretty-print.h"
30#include "gimple-iterator.h"
31#include "tree-cfg.h"
32#include "fold-const.h"
33#include "tree-cfg.h"
34#include "cfgloop.h"
35#include "tree-scalar-evolution.h"
36#include "gimple-range.h"
37#include "gimple-fold.h"
38#include "gimple-walk.h"
39
40gimple_ranger::gimple_ranger (bool use_imm_uses) :
41 non_executable_edge_flag (cfun),
42 m_cache (non_executable_edge_flag, use_imm_uses),
43 tracer (""),
44 current_bb (NULL)
45{
46 // If the cache has a relation oracle, use it.
47 m_oracle = m_cache.oracle ();
48 if (dump_file && (param_ranger_debug & RANGER_DEBUG_TRACE))
49 tracer.enable_trace ();
50 m_stmt_list.create (nelems: 0);
51 m_stmt_list.safe_grow (num_ssa_names);
52 m_stmt_list.truncate (size: 0);
53
54 // Ensure the not_executable flag is clear everywhere.
55 if (flag_checking)
56 {
57 basic_block bb;
58 FOR_ALL_BB_FN (bb, cfun)
59 {
60 edge_iterator ei;
61 edge e;
62 FOR_EACH_EDGE (e, ei, bb->succs)
63 gcc_checking_assert ((e->flags & non_executable_edge_flag) == 0);
64 }
65 }
66}
67
68gimple_ranger::~gimple_ranger ()
69{
70 m_stmt_list.release ();
71}
72
73// Return a range_query which accesses just the known global values.
74
75range_query &
76gimple_ranger::const_query ()
77{
78 return m_cache.const_query ();
79}
80
81bool
82gimple_ranger::range_of_expr (vrange &r, tree expr, gimple *stmt)
83{
84 unsigned idx;
85 if (!gimple_range_ssa_p (exp: expr))
86 return get_tree_range (v&: r, expr, stmt);
87
88 if ((idx = tracer.header (str: "range_of_expr(")))
89 {
90 print_generic_expr (dump_file, expr, TDF_SLIM);
91 fputs (s: ")", stream: dump_file);
92 if (stmt)
93 {
94 fputs (s: " at stmt ", stream: dump_file);
95 print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM);
96 }
97 else
98 fputs (s: "\n", stream: dump_file);
99 }
100
101 // If there is no statement, just get the global value.
102 if (!stmt)
103 {
104 Value_Range tmp (TREE_TYPE (expr));
105 m_cache.get_global_range (r, name: expr);
106 // Pick up implied context information from the on-entry cache
107 // if current_bb is set. Do not attempt any new calculations.
108 if (current_bb && m_cache.block_range (r&: tmp, bb: current_bb, name: expr, calc: false))
109 {
110 r.intersect (tmp);
111 char str[80];
112 sprintf (s: str, format: "picked up range from bb %d\n",current_bb->index);
113 if (idx)
114 tracer.print (counter: idx, str);
115 }
116 }
117 // For a debug stmt, pick the best value currently available, do not
118 // trigger new value calculations. PR 100781.
119 else if (is_gimple_debug (gs: stmt))
120 m_cache.range_of_expr (r, name: expr, stmt);
121 else
122 {
123 basic_block bb = gimple_bb (g: stmt);
124 gimple *def_stmt = SSA_NAME_DEF_STMT (expr);
125
126 // If name is defined in this block, try to get an range from S.
127 if (def_stmt && gimple_bb (g: def_stmt) == bb)
128 {
129 // Declared in this block, if it has a global set, check for an
130 // override from a block walk, otherwise calculate it.
131 if (m_cache.get_global_range (r, name: expr))
132 m_cache.block_range (r, bb, name: expr, calc: false);
133 else
134 range_of_stmt (r, def_stmt, name: expr);
135 }
136 // Otherwise OP comes from outside this block, use range on entry.
137 else
138 range_on_entry (r, bb, name: expr);
139 }
140 if (idx)
141 tracer.trailer (counter: idx, caller: "range_of_expr", result: true, name: expr, r);
142 return true;
143}
144
145// Return the range of NAME on entry to block BB in R.
146
147void
148gimple_ranger::range_on_entry (vrange &r, basic_block bb, tree name)
149{
150 Value_Range entry_range (TREE_TYPE (name));
151 gcc_checking_assert (gimple_range_ssa_p (name));
152
153 unsigned idx;
154 if ((idx = tracer.header (str: "range_on_entry (")))
155 {
156 print_generic_expr (dump_file, name, TDF_SLIM);
157 fprintf (stream: dump_file, format: ") to BB %d\n", bb->index);
158 }
159
160 // Start with any known range
161 range_of_stmt (r, SSA_NAME_DEF_STMT (name), name);
162
163 // Now see if there is any on_entry value which may refine it.
164 if (m_cache.block_range (r&: entry_range, bb, name))
165 r.intersect (entry_range);
166
167 if (idx)
168 tracer.trailer (counter: idx, caller: "range_on_entry", result: true, name, r);
169}
170
171// Calculate the range for NAME at the end of block BB and return it in R.
172// Return false if no range can be calculated.
173
174void
175gimple_ranger::range_on_exit (vrange &r, basic_block bb, tree name)
176{
177 // on-exit from the exit block?
178 gcc_checking_assert (gimple_range_ssa_p (name));
179
180 unsigned idx;
181 if ((idx = tracer.header (str: "range_on_exit (")))
182 {
183 print_generic_expr (dump_file, name, TDF_SLIM);
184 fprintf (stream: dump_file, format: ") from BB %d\n", bb->index);
185 }
186
187 gimple *s = SSA_NAME_DEF_STMT (name);
188 basic_block def_bb = gimple_bb (g: s);
189 // If this is not the definition block, get the range on the last stmt in
190 // the block... if there is one.
191 if (def_bb != bb)
192 s = last_nondebug_stmt (bb);
193 // If there is no statement provided, get the range_on_entry for this block.
194 if (s)
195 range_of_expr (r, expr: name, stmt: s);
196 else
197 range_on_entry (r, bb, name);
198 gcc_checking_assert (r.undefined_p ()
199 || range_compatible_p (r.type (), TREE_TYPE (name)));
200
201 if (idx)
202 tracer.trailer (counter: idx, caller: "range_on_exit", result: true, name, r);
203}
204
205// Calculate a range for NAME on edge E and return it in R.
206
207bool
208gimple_ranger::range_on_edge (vrange &r, edge e, tree name)
209{
210 Value_Range edge_range (TREE_TYPE (name));
211
212 if (!r.supports_type_p (TREE_TYPE (name)))
213 return false;
214
215 // Do not process values along abnormal edges.
216 if (e->flags & EDGE_ABNORMAL)
217 return get_tree_range (v&: r, expr: name, NULL);
218
219 unsigned idx;
220 if ((idx = tracer.header (str: "range_on_edge (")))
221 {
222 print_generic_expr (dump_file, name, TDF_SLIM);
223 fprintf (stream: dump_file, format: ") on edge %d->%d\n", e->src->index, e->dest->index);
224 }
225
226 // Check to see if the edge is executable.
227 if ((e->flags & non_executable_edge_flag))
228 {
229 r.set_undefined ();
230 if (idx)
231 tracer.trailer (counter: idx, caller: "range_on_edge [Unexecutable] ", result: true,
232 name, r);
233 return true;
234 }
235
236 bool res = true;
237 if (!gimple_range_ssa_p (exp: name))
238 res = get_tree_range (v&: r, expr: name, NULL);
239 else
240 {
241 range_on_exit (r, bb: e->src, name);
242 // If this is not an abnormal edge, check for a non-null exit .
243 if ((e->flags & (EDGE_EH | EDGE_ABNORMAL)) == 0)
244 m_cache.m_exit.maybe_adjust_range (r, name, bb: e->src);
245 gcc_checking_assert (r.undefined_p ()
246 || range_compatible_p (r.type(), TREE_TYPE (name)));
247
248 // Check to see if NAME is defined on edge e.
249 if (m_cache.range_on_edge (r&: edge_range, e, expr: name))
250 r.intersect (edge_range);
251 }
252
253 if (idx)
254 tracer.trailer (counter: idx, caller: "range_on_edge", result: res, name, r);
255 return res;
256}
257
258// fold_range wrapper for range_of_stmt to use as an internal client.
259
260bool
261gimple_ranger::fold_range_internal (vrange &r, gimple *s, tree name)
262{
263 fold_using_range f;
264 fur_depend src (s, &(gori ()), this);
265 return f.fold_stmt (r, s, src, name);
266}
267
268// Calculate a range for statement S and return it in R. If NAME is
269// provided it represents the SSA_NAME on the LHS of the statement.
270// It is only required if there is more than one lhs/output. Check
271// the global cache for NAME first to see if the evaluation can be
272// avoided. If a range cannot be calculated, return false and UNDEFINED.
273
274bool
275gimple_ranger::range_of_stmt (vrange &r, gimple *s, tree name)
276{
277 bool res;
278 r.set_undefined ();
279
280 unsigned idx;
281 if ((idx = tracer.header (str: "range_of_stmt (")))
282 {
283 if (name)
284 print_generic_expr (dump_file, name, TDF_SLIM);
285 fputs (s: ") at stmt ", stream: dump_file);
286 print_gimple_stmt (dump_file, s, 0, TDF_SLIM);
287 }
288
289 if (!name)
290 name = gimple_get_lhs (s);
291
292 // If no name, simply call the base routine.
293 if (!name)
294 {
295 res = fold_range_internal (r, s, NULL_TREE);
296 if (res && is_a <gcond *> (p: s))
297 {
298 // Update any exports in the cache if this is a gimple cond statement.
299 tree exp;
300 basic_block bb = gimple_bb (g: s);
301 FOR_EACH_GORI_EXPORT_NAME (m_cache.m_gori, bb, exp)
302 m_cache.propagate_updated_value (name: exp, bb);
303 }
304 }
305 else if (!gimple_range_ssa_p (exp: name))
306 res = get_tree_range (v&: r, expr: name, NULL);
307 else
308 {
309 bool current;
310 // Check if the stmt has already been processed.
311 if (m_cache.get_global_range (r, name, current_p&: current))
312 {
313 // If it isn't stale, use this cached value.
314 if (current)
315 {
316 if (idx)
317 tracer.trailer (counter: idx, caller: " cached", result: true, name, r);
318 return true;
319 }
320 }
321 else
322 prefill_stmt_dependencies (ssa: name);
323
324 // Calculate a new value.
325 Value_Range tmp (TREE_TYPE (name));
326 fold_range_internal (r&: tmp, s, name);
327
328 // Combine the new value with the old value. This is required because
329 // the way value propagation works, when the IL changes on the fly we
330 // can sometimes get different results. See PR 97741.
331 bool changed = r.intersect (tmp);
332 m_cache.set_global_range (name, r, changed);
333 res = true;
334 }
335
336 if (idx)
337 tracer.trailer (counter: idx, caller: "range_of_stmt", result: res, name, r);
338 return res;
339}
340
341
342// Check if NAME is a dependency that needs resolving, and push it on the
343// stack if so. R is a scratch range.
344
345inline void
346gimple_ranger::prefill_name (vrange &r, tree name)
347{
348 if (!gimple_range_ssa_p (exp: name))
349 return;
350 gimple *stmt = SSA_NAME_DEF_STMT (name);
351 if (!gimple_range_op_handler::supported_p (s: stmt) && !is_a<gphi *> (p: stmt))
352 return;
353
354 // If this op has not been processed yet, then push it on the stack
355 if (!m_cache.get_global_range (r, name))
356 {
357 bool current;
358 // Set the global cache value and mark as alway_current.
359 m_cache.get_global_range (r, name, current_p&: current);
360 m_stmt_list.safe_push (obj: name);
361 }
362}
363
364// This routine will seed the global cache with most of the dependencies of
365// NAME. This prevents excessive call depth through the normal API.
366
367void
368gimple_ranger::prefill_stmt_dependencies (tree ssa)
369{
370 if (SSA_NAME_IS_DEFAULT_DEF (ssa))
371 return;
372
373 unsigned idx;
374 gimple *stmt = SSA_NAME_DEF_STMT (ssa);
375 gcc_checking_assert (stmt && gimple_bb (stmt));
376
377 // Only pre-process range-ops and phis.
378 if (!gimple_range_op_handler::supported_p (s: stmt) && !is_a<gphi *> (p: stmt))
379 return;
380
381 // Mark where on the stack we are starting.
382 unsigned start = m_stmt_list.length ();
383 m_stmt_list.safe_push (obj: ssa);
384
385 idx = tracer.header (str: "ROS dependence fill\n");
386
387 // Loop until back at the start point.
388 while (m_stmt_list.length () > start)
389 {
390 tree name = m_stmt_list.last ();
391 // NULL is a marker which indicates the next name in the stack has now
392 // been fully resolved, so we can fold it.
393 if (!name)
394 {
395 // Pop the NULL, then pop the name.
396 m_stmt_list.pop ();
397 name = m_stmt_list.pop ();
398 // Don't fold initial request, it will be calculated upon return.
399 if (m_stmt_list.length () > start)
400 {
401 // Fold and save the value for NAME.
402 stmt = SSA_NAME_DEF_STMT (name);
403 Value_Range r (TREE_TYPE (name));
404 fold_range_internal (r, s: stmt, name);
405 // Make sure we don't lose any current global info.
406 Value_Range tmp (TREE_TYPE (name));
407 m_cache.get_global_range (r&: tmp, name);
408 bool changed = tmp.intersect (r);
409 m_cache.set_global_range (name, r: tmp, changed);
410 }
411 continue;
412 }
413
414 // Add marker indicating previous NAME in list should be folded
415 // when we get to this NULL.
416 m_stmt_list.safe_push (NULL_TREE);
417 stmt = SSA_NAME_DEF_STMT (name);
418
419 if (idx)
420 {
421 tracer.print (counter: idx, str: "ROS dep fill (");
422 print_generic_expr (dump_file, name, TDF_SLIM);
423 fputs (s: ") at stmt ", stream: dump_file);
424 print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM);
425 }
426
427 gphi *phi = dyn_cast <gphi *> (p: stmt);
428 if (phi)
429 {
430 Value_Range r (TREE_TYPE (gimple_phi_result (phi)));
431 for (unsigned x = 0; x < gimple_phi_num_args (gs: phi); x++)
432 prefill_name (r, name: gimple_phi_arg_def (gs: phi, index: x));
433 }
434 else
435 {
436 gimple_range_op_handler handler (stmt);
437 if (handler)
438 {
439 tree op = handler.operand2 ();
440 if (op)
441 {
442 Value_Range r (TREE_TYPE (op));
443 prefill_name (r, name: op);
444 }
445 op = handler.operand1 ();
446 if (op)
447 {
448 Value_Range r (TREE_TYPE (op));
449 prefill_name (r, name: op);
450 }
451 }
452 }
453 }
454 if (idx)
455 {
456 unsupported_range r;
457 tracer.trailer (counter: idx, caller: "ROS ", result: false, name: ssa, r);
458 }
459}
460
461
462// This routine will invoke the gimple fold_stmt routine, providing context to
463// range_of_expr calls via an private internal API.
464
465bool
466gimple_ranger::fold_stmt (gimple_stmt_iterator *gsi, tree (*valueize) (tree))
467{
468 gimple *stmt = gsi_stmt (i: *gsi);
469 current_bb = gimple_bb (g: stmt);
470 bool ret = ::fold_stmt (gsi, valueize);
471 current_bb = NULL;
472 return ret;
473}
474
475// Called during dominator walks to register any inferred ranges that take
476// effect from this point forward.
477
478void
479gimple_ranger::register_inferred_ranges (gimple *s)
480{
481 // First, export the LHS if it is a new global range.
482 tree lhs = gimple_get_lhs (s);
483 if (lhs)
484 {
485 Value_Range tmp (TREE_TYPE (lhs));
486 if (range_of_stmt (r&: tmp, s, name: lhs) && !tmp.varying_p ()
487 && set_range_info (lhs, tmp) && dump_file)
488 {
489 fprintf (stream: dump_file, format: "Global Exported: ");
490 print_generic_expr (dump_file, lhs, TDF_SLIM);
491 fprintf (stream: dump_file, format: " = ");
492 tmp.dump (dump_file);
493 fputc (c: '\n', stream: dump_file);
494 }
495 }
496 m_cache.apply_inferred_ranges (s);
497}
498
499// This function will walk the statements in BB to determine if any
500// discovered inferred ranges in the block have any transitive effects,
501// and if so, register those effects in BB.
502
503void
504gimple_ranger::register_transitive_inferred_ranges (basic_block bb)
505{
506 // Return if there are no inferred ranges in BB.
507 infer_range_manager &infer = m_cache.m_exit;
508 if (!infer.has_range_p (bb))
509 return;
510
511 if (dump_file && (dump_flags & TDF_DETAILS))
512 fprintf (stream: dump_file, format: "Checking for transitive inferred ranges in BB %d\n",
513 bb->index);
514
515 for (gimple_stmt_iterator si = gsi_start_bb (bb); !gsi_end_p (i: si);
516 gsi_next (i: &si))
517 {
518 gimple *s = gsi_stmt (i: si);
519 tree lhs = gimple_get_lhs (s);
520 // If the LHS already has an inferred effect, leave it be.
521 if (!gimple_range_ssa_p (exp: lhs) || infer.has_range_p (name: lhs, bb))
522 continue;
523 // Pick up global value.
524 Value_Range g (TREE_TYPE (lhs));
525 range_of_expr (r&: g, expr: lhs);
526
527 // If either dependency has an inferred range, check if recalculating
528 // the LHS is different than the global value. If so, register it as
529 // an inferred range as well.
530 Value_Range r (TREE_TYPE (lhs));
531 r.set_undefined ();
532 tree name1 = gori ().depend1 (name: lhs);
533 tree name2 = gori ().depend2 (name: lhs);
534 if ((name1 && infer.has_range_p (name: name1, bb))
535 || (name2 && infer.has_range_p (name: name2, bb)))
536 {
537 // Check if folding S produces a different result.
538 if (fold_range (r, s, q: this) && g != r)
539 {
540 infer.add_range (name: lhs, bb, r);
541 m_cache.register_inferred_value (r, name: lhs, bb);
542 }
543 }
544 }
545}
546
547// This routine will export whatever global ranges are known to GCC
548// SSA_RANGE_NAME_INFO and SSA_NAME_PTR_INFO fields.
549
550void
551gimple_ranger::export_global_ranges ()
552{
553 /* Cleared after the table header has been printed. */
554 bool print_header = true;
555 for (unsigned x = 1; x < num_ssa_names; x++)
556 {
557 tree name = ssa_name (x);
558 if (!name)
559 continue;
560 Value_Range r (TREE_TYPE (name));
561 if (name && !SSA_NAME_IN_FREE_LIST (name)
562 && gimple_range_ssa_p (exp: name)
563 && m_cache.get_global_range (r, name)
564 && !r.varying_p())
565 {
566 bool updated = set_range_info (name, r);
567 if (!updated || !dump_file)
568 continue;
569
570 if (print_header)
571 {
572 /* Print the header only when there's something else
573 to print below. */
574 fprintf (stream: dump_file, format: "Exported global range table:\n");
575 fprintf (stream: dump_file, format: "============================\n");
576 print_header = false;
577 }
578
579 print_generic_expr (dump_file, name , TDF_SLIM);
580 fprintf (stream: dump_file, format: " : ");
581 r.dump (dump_file);
582 fprintf (stream: dump_file, format: "\n");
583 }
584 }
585}
586
587// Print the known table values to file F.
588
589void
590gimple_ranger::dump_bb (FILE *f, basic_block bb)
591{
592 unsigned x;
593 edge_iterator ei;
594 edge e;
595 fprintf (stream: f, format: "\n=========== BB %d ============\n", bb->index);
596 m_cache.dump_bb (f, bb);
597
598 ::dump_bb (f, bb, 4, TDF_NONE);
599
600 // Now find any globals defined in this block.
601 for (x = 1; x < num_ssa_names; x++)
602 {
603 tree name = ssa_name (x);
604 if (!gimple_range_ssa_p (exp: name) || !SSA_NAME_DEF_STMT (name))
605 continue;
606 Value_Range range (TREE_TYPE (name));
607 if (gimple_bb (SSA_NAME_DEF_STMT (name)) == bb
608 && m_cache.get_global_range (r&: range, name))
609 {
610 if (!range.varying_p ())
611 {
612 print_generic_expr (f, name, TDF_SLIM);
613 fprintf (stream: f, format: " : ");
614 range.dump (f);
615 fprintf (stream: f, format: "\n");
616 }
617
618 }
619 }
620
621 // And now outgoing edges, if they define anything.
622 FOR_EACH_EDGE (e, ei, bb->succs)
623 {
624 for (x = 1; x < num_ssa_names; x++)
625 {
626 tree name = gimple_range_ssa_p (ssa_name (x));
627 if (!name || !gori ().has_edge_range_p (name, e))
628 continue;
629
630 Value_Range range (TREE_TYPE (name));
631 if (m_cache.range_on_edge (r&: range, e, expr: name))
632 {
633 gimple *s = SSA_NAME_DEF_STMT (name);
634 Value_Range tmp_range (TREE_TYPE (name));
635 // Only print the range if this is the def block, or
636 // the on entry cache for either end of the edge is
637 // set.
638 if ((s && bb == gimple_bb (g: s)) ||
639 m_cache.block_range (r&: tmp_range, bb, name, calc: false) ||
640 m_cache.block_range (r&: tmp_range, bb: e->dest, name, calc: false))
641 {
642 if (!range.varying_p ())
643 {
644 fprintf (stream: f, format: "%d->%d ", e->src->index,
645 e->dest->index);
646 char c = ' ';
647 if (e->flags & EDGE_TRUE_VALUE)
648 fprintf (stream: f, format: " (T)%c", c);
649 else if (e->flags & EDGE_FALSE_VALUE)
650 fprintf (stream: f, format: " (F)%c", c);
651 else
652 fprintf (stream: f, format: " ");
653 print_generic_expr (f, name, TDF_SLIM);
654 fprintf(stream: f, format: " : \t");
655 range.dump(f);
656 fprintf (stream: f, format: "\n");
657 }
658 }
659 }
660 }
661 }
662}
663
664// Print the known table values to file F.
665
666void
667gimple_ranger::dump (FILE *f)
668{
669 basic_block bb;
670
671 FOR_EACH_BB_FN (bb, cfun)
672 dump_bb (f, bb);
673
674 m_cache.dump (f);
675}
676
677void
678gimple_ranger::debug ()
679{
680 dump (stderr);
681}
682
683/* Create a new ranger instance and associate it with function FUN.
684 Each call must be paired with a call to disable_ranger to release
685 resources. */
686
687gimple_ranger *
688enable_ranger (struct function *fun, bool use_imm_uses)
689{
690 gimple_ranger *r;
691
692 bitmap_obstack_initialize (NULL);
693
694 gcc_checking_assert (!fun->x_range_query);
695 r = new gimple_ranger (use_imm_uses);
696 fun->x_range_query = r;
697
698 return r;
699}
700
701/* Destroy and release the ranger instance associated with function FUN
702 and replace it the global ranger. */
703
704void
705disable_ranger (struct function *fun)
706{
707 gcc_checking_assert (fun->x_range_query);
708 delete fun->x_range_query;
709 fun->x_range_query = NULL;
710
711 bitmap_obstack_release (NULL);
712}
713
714// ------------------------------------------------------------------------
715
716// If there is a non-varying value associated with NAME, return true and the
717// range in R.
718
719bool
720assume_query::assume_range_p (vrange &r, tree name)
721{
722 if (global.get_range (r, name))
723 return !r.varying_p ();
724 return false;
725}
726
727// Query used by GORI to pick up any known value on entry to a block.
728
729bool
730assume_query::range_of_expr (vrange &r, tree expr, gimple *stmt)
731{
732 if (!gimple_range_ssa_p (exp: expr))
733 return get_tree_range (v&: r, expr, stmt);
734
735 if (!global.get_range (r, name: expr))
736 r.set_varying (TREE_TYPE (expr));
737 return true;
738}
739
740// If the current function returns an integral value, and has a single return
741// statement, it will calculate any SSA_NAMES it can determine ranges for
742// assuming the function returns 1.
743
744assume_query::assume_query ()
745{
746 basic_block exit_bb = EXIT_BLOCK_PTR_FOR_FN (cfun);
747 if (single_pred_p (bb: exit_bb))
748 {
749 basic_block bb = single_pred (bb: exit_bb);
750 gimple_stmt_iterator gsi = gsi_last_nondebug_bb (bb);
751 if (gsi_end_p (i: gsi))
752 return;
753 gimple *s = gsi_stmt (i: gsi);
754 if (!is_a<greturn *> (p: s))
755 return;
756 greturn *gret = as_a<greturn *> (p: s);
757 tree op = gimple_return_retval (gs: gret);
758 if (!gimple_range_ssa_p (exp: op))
759 return;
760 tree lhs_type = TREE_TYPE (op);
761 if (!irange::supports_p (type: lhs_type))
762 return;
763
764 unsigned prec = TYPE_PRECISION (lhs_type);
765 int_range<2> lhs_range (lhs_type, wi::one (precision: prec), wi::one (precision: prec));
766 global.set_range (name: op, r: lhs_range);
767
768 gimple *def = SSA_NAME_DEF_STMT (op);
769 if (!def || gimple_get_lhs (def) != op)
770 return;
771 fur_stmt src (gret, this);
772 calculate_stmt (s: def, lhs_range, src);
773 }
774}
775
776// Evaluate operand OP on statement S, using the provided LHS range.
777// If successful, set the range in the global table, then visit OP's def stmt.
778
779void
780assume_query::calculate_op (tree op, gimple *s, vrange &lhs, fur_source &src)
781{
782 Value_Range op_range (TREE_TYPE (op));
783 if (m_gori.compute_operand_range (r&: op_range, stmt: s, lhs, name: op, src)
784 && !op_range.varying_p ())
785 {
786 // Set the global range, merging if there is already a range.
787 global.merge_range (name: op, r: op_range);
788 gimple *def_stmt = SSA_NAME_DEF_STMT (op);
789 if (def_stmt && gimple_get_lhs (def_stmt) == op)
790 calculate_stmt (s: def_stmt, lhs_range&: op_range, src);
791 }
792}
793
794// Evaluate PHI statement, using the provided LHS range.
795// Check each constant argument predecessor if it can be taken
796// provide LHS to any symbolic arguments, and process their def statements.
797
798void
799assume_query::calculate_phi (gphi *phi, vrange &lhs_range, fur_source &src)
800{
801 for (unsigned x= 0; x < gimple_phi_num_args (gs: phi); x++)
802 {
803 tree arg = gimple_phi_arg_def (gs: phi, index: x);
804 Value_Range arg_range (TREE_TYPE (arg));
805 if (gimple_range_ssa_p (exp: arg))
806 {
807 // A symbol arg will be the LHS value.
808 arg_range = lhs_range;
809 range_cast (r&: arg_range, TREE_TYPE (arg));
810 if (!global.get_range (r&: arg_range, name: arg))
811 {
812 global.set_range (name: arg, r: arg_range);
813 gimple *def_stmt = SSA_NAME_DEF_STMT (arg);
814 if (def_stmt && gimple_get_lhs (def_stmt) == arg)
815 calculate_stmt (s: def_stmt, lhs_range&: arg_range, src);
816 }
817 }
818 else if (get_tree_range (v&: arg_range, expr: arg, NULL))
819 {
820 // If this is a constant value that differs from LHS, this
821 // edge cannot be taken.
822 arg_range.intersect (r: lhs_range);
823 if (arg_range.undefined_p ())
824 continue;
825 // Otherwise check the condition feeding this edge.
826 edge e = gimple_phi_arg_edge (phi, i: x);
827 check_taken_edge (e, src);
828 }
829 }
830}
831
832// If an edge is known to be taken, examine the outgoing edge to see
833// if it carries any range information that can also be evaluated.
834
835void
836assume_query::check_taken_edge (edge e, fur_source &src)
837{
838 gimple *stmt = gimple_outgoing_range_stmt_p (bb: e->src);
839 if (stmt && is_a<gcond *> (p: stmt))
840 {
841 int_range<2> cond;
842 gcond_edge_range (r&: cond, e);
843 calculate_stmt (s: stmt, lhs_range&: cond, src);
844 }
845}
846
847// Evaluate statement S which produces range LHS_RANGE.
848
849void
850assume_query::calculate_stmt (gimple *s, vrange &lhs_range, fur_source &src)
851{
852 gimple_range_op_handler handler (s);
853 if (handler)
854 {
855 tree op = gimple_range_ssa_p (exp: handler.operand1 ());
856 if (op)
857 calculate_op (op, s, lhs&: lhs_range, src);
858 op = gimple_range_ssa_p (exp: handler.operand2 ());
859 if (op)
860 calculate_op (op, s, lhs&: lhs_range, src);
861 }
862 else if (is_a<gphi *> (p: s))
863 {
864 calculate_phi (phi: as_a<gphi *> (p: s), lhs_range, src);
865 // Don't further check predecessors of blocks with PHIs.
866 return;
867 }
868
869 // Even if the walk back terminates before the top, if this is a single
870 // predecessor block, see if the predecessor provided any ranges to get here.
871 if (single_pred_p (bb: gimple_bb (g: s)))
872 check_taken_edge (e: single_pred_edge (bb: gimple_bb (g: s)), src);
873}
874
875// Show everything that was calculated.
876
877void
878assume_query::dump (FILE *f)
879{
880 fprintf (stream: f, format: "Assumption details calculated:\n");
881 for (unsigned i = 0; i < num_ssa_names; i++)
882 {
883 tree name = ssa_name (i);
884 if (!name || !gimple_range_ssa_p (exp: name))
885 continue;
886 tree type = TREE_TYPE (name);
887 if (!Value_Range::supports_type_p (type))
888 continue;
889
890 Value_Range assume_range (type);
891 if (assume_range_p (r&: assume_range, name))
892 {
893 print_generic_expr (f, name, TDF_SLIM);
894 fprintf (stream: f, format: " -> ");
895 assume_range.dump (f);
896 fputc (c: '\n', stream: f);
897 }
898 }
899 fprintf (stream: f, format: "------------------------------\n");
900}
901
902// ---------------------------------------------------------------------------
903
904
905// Create a DOM based ranger for use by a DOM walk pass.
906
907dom_ranger::dom_ranger () : m_global (), m_out ()
908{
909 m_freelist.create (nelems: 0);
910 m_freelist.truncate (size: 0);
911 m_e0.create (nelems: 0);
912 m_e0.safe_grow_cleared (last_basic_block_for_fn (cfun));
913 m_e1.create (nelems: 0);
914 m_e1.safe_grow_cleared (last_basic_block_for_fn (cfun));
915 m_pop_list = BITMAP_ALLOC (NULL);
916 if (dump_file && (param_ranger_debug & RANGER_DEBUG_TRACE))
917 tracer.enable_trace ();
918}
919
920// Dispose of a DOM ranger.
921
922dom_ranger::~dom_ranger ()
923{
924 if (dump_file && (dump_flags & TDF_DETAILS))
925 {
926 fprintf (stream: dump_file, format: "Non-varying global ranges:\n");
927 fprintf (stream: dump_file, format: "=========================:\n");
928 m_global.dump (f: dump_file);
929 }
930 BITMAP_FREE (m_pop_list);
931 m_e1.release ();
932 m_e0.release ();
933 m_freelist.release ();
934}
935
936// Implement range of EXPR on stmt S, and return it in R.
937// Return false if no range can be calculated.
938
939bool
940dom_ranger::range_of_expr (vrange &r, tree expr, gimple *s)
941{
942 unsigned idx;
943 if (!gimple_range_ssa_p (exp: expr))
944 return get_tree_range (v&: r, expr, stmt: s);
945
946 if ((idx = tracer.header (str: "range_of_expr ")))
947 {
948 print_generic_expr (dump_file, expr, TDF_SLIM);
949 if (s)
950 {
951 fprintf (stream: dump_file, format: " at ");
952 print_gimple_stmt (dump_file, s, 0, TDF_SLIM);
953 }
954 else
955 fprintf (stream: dump_file, format: "\n");
956 }
957
958 if (s)
959 range_in_bb (r, bb: gimple_bb (g: s), name: expr);
960 else
961 m_global.range_of_expr (r, expr, stmt: s);
962
963 if (idx)
964 tracer.trailer (counter: idx, caller: " ", result: true, name: expr, r);
965 return true;
966}
967
968
969// Return TRUE and the range if edge E has a range set for NAME in
970// block E->src.
971
972bool
973dom_ranger::edge_range (vrange &r, edge e, tree name)
974{
975 bool ret = false;
976 basic_block bb = e->src;
977
978 // Check if BB has any outgoing ranges on edge E.
979 ssa_lazy_cache *out = NULL;
980 if (EDGE_SUCC (bb, 0) == e)
981 out = m_e0[bb->index];
982 else if (EDGE_SUCC (bb, 1) == e)
983 out = m_e1[bb->index];
984
985 // If there is an edge vector and it has a range, pick it up.
986 if (out && out->has_range (name))
987 ret = out->get_range (r, name);
988
989 return ret;
990}
991
992
993// Return the range of EXPR on edge E in R.
994// Return false if no range can be calculated.
995
996bool
997dom_ranger::range_on_edge (vrange &r, edge e, tree expr)
998{
999 basic_block bb = e->src;
1000 unsigned idx;
1001 if ((idx = tracer.header (str: "range_on_edge ")))
1002 {
1003 fprintf (stream: dump_file, format: "%d->%d for ",e->src->index, e->dest->index);
1004 print_generic_expr (dump_file, expr, TDF_SLIM);
1005 fputc (c: '\n',stream: dump_file);
1006 }
1007
1008 if (!gimple_range_ssa_p (exp: expr))
1009 return get_tree_range (v&: r, expr, NULL);
1010
1011 if (!edge_range (r, e, name: expr))
1012 range_in_bb (r, bb, name: expr);
1013
1014 if (idx)
1015 tracer.trailer (counter: idx, caller: " ", result: true, name: expr, r);
1016 return true;
1017}
1018
1019// Return the range of NAME as it exists at the end of block BB in R.
1020
1021void
1022dom_ranger::range_in_bb (vrange &r, basic_block bb, tree name)
1023{
1024 basic_block def_bb = gimple_bb (SSA_NAME_DEF_STMT (name));
1025 // Loop through dominators until we get to the entry block, or we find
1026 // either the defintion block for NAME, or a single pred edge with a range.
1027 while (bb != ENTRY_BLOCK_PTR_FOR_FN (cfun))
1028 {
1029 // If we hit the deifntion block, pick up the global value.
1030 if (bb == def_bb)
1031 {
1032 m_global.range_of_expr (r, expr: name);
1033 return;
1034 }
1035 // If its a single pred, check the outgoing range of the edge.
1036 if (EDGE_COUNT (bb->preds) == 1
1037 && edge_range (r, EDGE_PRED (bb, 0), name))
1038 return;
1039 // Otherwise move up to the dominator, and check again.
1040 bb = get_immediate_dominator (CDI_DOMINATORS, bb);
1041 }
1042 m_global.range_of_expr (r, expr: name);
1043}
1044
1045
1046// Calculate the range of NAME, as the def of stmt S and return it in R.
1047// Return FALSE if no range cqn be calculated.
1048// Also set the global range for NAME as this should only be called within
1049// the def block during a DOM walk.
1050// Outgoing edges were pre-calculated, so when we establish a global defintion
1051// check if any outgoing edges hav ranges that can be combined with the
1052// global.
1053
1054bool
1055dom_ranger::range_of_stmt (vrange &r, gimple *s, tree name)
1056{
1057 unsigned idx;
1058 bool ret;
1059 if (!name)
1060 name = gimple_range_ssa_p (exp: gimple_get_lhs (s));
1061
1062 gcc_checking_assert (!name || name == gimple_get_lhs (s));
1063
1064 if ((idx = tracer.header (str: "range_of_stmt ")))
1065 print_gimple_stmt (dump_file, s, 0, TDF_SLIM);
1066
1067 // Its already been calculated.
1068 if (name && m_global.has_range (name))
1069 {
1070 ret = m_global.range_of_expr (r, expr: name, stmt: s);
1071 if (idx)
1072 tracer.trailer (counter: idx, caller: " Already had value ", result: ret, name, r);
1073 return ret;
1074 }
1075
1076 // If there is a new calculated range and it is not varying, set
1077 // a global range.
1078 ret = fold_range (r, s, q: this);
1079 if (ret && name && m_global.merge_range (name, r) && !r.varying_p ())
1080 {
1081 if (set_range_info (name, r) && dump_file)
1082 {
1083 fprintf (stream: dump_file, format: "Global Exported: ");
1084 print_generic_expr (dump_file, name, TDF_SLIM);
1085 fprintf (stream: dump_file, format: " = ");
1086 r.dump (dump_file);
1087 fputc (c: '\n', stream: dump_file);
1088 }
1089 basic_block bb = gimple_bb (g: s);
1090 unsigned bbi = bb->index;
1091 Value_Range vr (TREE_TYPE (name));
1092 // If there is a range on edge 0, update it.
1093 if (m_e0[bbi] && m_e0[bbi]->has_range (name))
1094 {
1095 if (m_e0[bbi]->merge_range (name, r) && dump_file
1096 && (dump_flags & TDF_DETAILS))
1097 {
1098 fprintf (stream: dump_file, format: "Outgoing range for ");
1099 print_generic_expr (dump_file, name, TDF_SLIM);
1100 fprintf (stream: dump_file, format: " updated on edge %d->%d : ", bbi,
1101 EDGE_SUCC (bb, 0)->dest->index);
1102 if (m_e0[bbi]->get_range (r&: vr, name))
1103 vr.dump (dump_file);
1104 fputc (c: '\n', stream: dump_file);
1105 }
1106 }
1107 // If there is a range on edge 1, update it.
1108 if (m_e1[bbi] && m_e1[bbi]->has_range (name))
1109 {
1110 if (m_e1[bbi]->merge_range (name, r) && dump_file
1111 && (dump_flags & TDF_DETAILS))
1112 {
1113 fprintf (stream: dump_file, format: "Outgoing range for ");
1114 print_generic_expr (dump_file, name, TDF_SLIM);
1115 fprintf (stream: dump_file, format: " updated on edge %d->%d : ", bbi,
1116 EDGE_SUCC (bb, 1)->dest->index);
1117 if (m_e1[bbi]->get_range (r&: vr, name))
1118 vr.dump (dump_file);
1119 fputc (c: '\n', stream: dump_file);
1120 }
1121 }
1122 }
1123 if (idx)
1124 tracer.trailer (counter: idx, caller: " ", result: ret, name, r);
1125 return ret;
1126}
1127
1128// Check if GORI has an ranges on edge E. If there re, store them in
1129// either the E0 or E1 vector based on EDGE_0.
1130// If there are no ranges, put the empty lazy_cache entry on the freelist
1131// for use next time.
1132
1133void
1134dom_ranger::maybe_push_edge (edge e, bool edge_0)
1135{
1136 ssa_lazy_cache *e_cache;
1137 if (!m_freelist.is_empty ())
1138 e_cache = m_freelist.pop ();
1139 else
1140 e_cache = new ssa_lazy_cache;
1141 gori_on_edge (r&: *e_cache, e, query: this, ogr: &m_out);
1142 if (e_cache->empty_p ())
1143 m_freelist.safe_push (obj: e_cache);
1144 else
1145 {
1146 if (edge_0)
1147 m_e0[e->src->index] = e_cache;
1148 else
1149 m_e1[e->src->index] = e_cache;
1150 }
1151}
1152
1153// Preprocess block BB. If there are any outgoing edges, precalculate
1154// the outgoing ranges and store them. Note these are done before
1155// we process the block, so global values have not been set yet.
1156// These are "pure" outgoing ranges inflicted by the condition.
1157
1158void
1159dom_ranger::pre_bb (basic_block bb)
1160{
1161 if (dump_file && (dump_flags & TDF_DETAILS))
1162 fprintf (stream: dump_file, format: "#FVRP entering BB %d\n", bb->index);
1163
1164 // Next, see if this block needs outgoing edges calculated.
1165 gimple_stmt_iterator gsi = gsi_last_nondebug_bb (bb);
1166 if (!gsi_end_p (i: gsi))
1167 {
1168 gimple *s = gsi_stmt (i: gsi);
1169 if (is_a<gcond *> (p: s) && gimple_range_op_handler::supported_p (s))
1170 {
1171 maybe_push_edge (EDGE_SUCC (bb, 0), edge_0: true);
1172 maybe_push_edge (EDGE_SUCC (bb, 1), edge_0: false);
1173
1174 if (dump_file && (dump_flags & TDF_DETAILS))
1175 {
1176 if (m_e0[bb->index])
1177 {
1178 fprintf (stream: dump_file, format: "\nEdge ranges BB %d->%d\n",
1179 bb->index, EDGE_SUCC (bb, 0)->dest->index);
1180 m_e0[bb->index]->dump(f: dump_file);
1181 }
1182 if (m_e1[bb->index])
1183 {
1184 fprintf (stream: dump_file, format: "\nEdge ranges BB %d->%d\n",
1185 bb->index, EDGE_SUCC (bb, 1)->dest->index);
1186 m_e1[bb->index]->dump(f: dump_file);
1187 }
1188 }
1189 }
1190 }
1191 if (dump_file && (dump_flags & TDF_DETAILS))
1192 fprintf (stream: dump_file, format: "#FVRP DONE entering BB %d\n", bb->index);
1193}
1194
1195// Perform any post block processing.
1196
1197void
1198dom_ranger::post_bb (basic_block)
1199{
1200}
1201

source code of gcc/gimple-range.cc