xref: /netbsd-src/external/gpl3/gcc/dist/gcc/gimple-range-fold.cc (revision b1e838363e3c6fc78a55519254d99869742dd33c)
1 /* Code for GIMPLE range related routines.
2    Copyright (C) 2019-2022 Free Software Foundation, Inc.
3    Contributed by Andrew MacLeod <amacleod@redhat.com>
4    and Aldy Hernandez <aldyh@redhat.com>.
5 
6 This file is part of GCC.
7 
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
11 any later version.
12 
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 GNU General Public License for more details.
17 
18 You should have received a copy of the GNU General Public License
19 along 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 "insn-codes.h"
27 #include "tree.h"
28 #include "gimple.h"
29 #include "ssa.h"
30 #include "gimple-pretty-print.h"
31 #include "optabs-tree.h"
32 #include "gimple-fold.h"
33 #include "wide-int.h"
34 #include "fold-const.h"
35 #include "case-cfn-macros.h"
36 #include "omp-general.h"
37 #include "cfgloop.h"
38 #include "tree-ssa-loop.h"
39 #include "tree-scalar-evolution.h"
40 #include "langhooks.h"
41 #include "vr-values.h"
42 #include "range.h"
43 #include "value-query.h"
44 #include "range-op.h"
45 #include "gimple-range.h"
46 // Construct a fur_source, and set the m_query field.
47 
fur_source(range_query * q)48 fur_source::fur_source (range_query *q)
49 {
50   if (q)
51     m_query = q;
52   else if (cfun)
53     m_query = get_range_query (cfun);
54   else
55     m_query = get_global_range_query ();
56   m_gori = NULL;
57 }
58 
59 // Invoke range_of_expr on EXPR.
60 
61 bool
get_operand(irange & r,tree expr)62 fur_source::get_operand (irange &r, tree expr)
63 {
64   return m_query->range_of_expr (r, expr);
65 }
66 
67 // Evaluate EXPR for this stmt as a PHI argument on edge E.  Use the current
68 // range_query to get the range on the edge.
69 
70 bool
get_phi_operand(irange & r,tree expr,edge e)71 fur_source::get_phi_operand (irange &r, tree expr, edge e)
72 {
73   return m_query->range_on_edge (r, e, expr);
74 }
75 
76 // Default is no relation.
77 
78 relation_kind
query_relation(tree op1 ATTRIBUTE_UNUSED,tree op2 ATTRIBUTE_UNUSED)79 fur_source::query_relation (tree op1 ATTRIBUTE_UNUSED,
80 			    tree op2 ATTRIBUTE_UNUSED)
81 {
82   return VREL_NONE;
83 }
84 
85 // Default registers nothing.
86 
87 void
register_relation(gimple * s ATTRIBUTE_UNUSED,relation_kind k ATTRIBUTE_UNUSED,tree op1 ATTRIBUTE_UNUSED,tree op2 ATTRIBUTE_UNUSED)88 fur_source::register_relation (gimple *s ATTRIBUTE_UNUSED,
89 			       relation_kind k ATTRIBUTE_UNUSED,
90 			       tree op1 ATTRIBUTE_UNUSED,
91 			       tree op2 ATTRIBUTE_UNUSED)
92 {
93 }
94 
95 // Default registers nothing.
96 
97 void
register_relation(edge e ATTRIBUTE_UNUSED,relation_kind k ATTRIBUTE_UNUSED,tree op1 ATTRIBUTE_UNUSED,tree op2 ATTRIBUTE_UNUSED)98 fur_source::register_relation (edge e ATTRIBUTE_UNUSED,
99 			       relation_kind k ATTRIBUTE_UNUSED,
100 			       tree op1 ATTRIBUTE_UNUSED,
101 			       tree op2 ATTRIBUTE_UNUSED)
102 {
103 }
104 
105 // This version of fur_source will pick a range up off an edge.
106 
107 class fur_edge : public fur_source
108 {
109 public:
110   fur_edge (edge e, range_query *q = NULL);
111   virtual bool get_operand (irange &r, tree expr) OVERRIDE;
112   virtual bool get_phi_operand (irange &r, tree expr, edge e) OVERRIDE;
113 private:
114   edge m_edge;
115 };
116 
117 // Instantiate an edge based fur_source.
118 
119 inline
fur_edge(edge e,range_query * q)120 fur_edge::fur_edge (edge e, range_query *q) : fur_source (q)
121 {
122   m_edge = e;
123 }
124 
125 // Get the value of EXPR on edge m_edge.
126 
127 bool
get_operand(irange & r,tree expr)128 fur_edge::get_operand (irange &r, tree expr)
129 {
130   return m_query->range_on_edge (r, m_edge, expr);
131 }
132 
133 // Evaluate EXPR for this stmt as a PHI argument on edge E.  Use the current
134 // range_query to get the range on the edge.
135 
136 bool
get_phi_operand(irange & r,tree expr,edge e)137 fur_edge::get_phi_operand (irange &r, tree expr, edge e)
138 {
139   // Edge to edge recalculations not supoprted yet, until we sort it out.
140   gcc_checking_assert (e == m_edge);
141   return m_query->range_on_edge (r, e, expr);
142 }
143 
144 // Instantiate a stmt based fur_source.
145 
fur_stmt(gimple * s,range_query * q)146 fur_stmt::fur_stmt (gimple *s, range_query *q) : fur_source (q)
147 {
148   m_stmt = s;
149 }
150 
151 // Retreive range of EXPR as it occurs as a use on stmt M_STMT.
152 
153 bool
get_operand(irange & r,tree expr)154 fur_stmt::get_operand (irange &r, tree expr)
155 {
156   return m_query->range_of_expr (r, expr, m_stmt);
157 }
158 
159 // Evaluate EXPR for this stmt as a PHI argument on edge E.  Use the current
160 // range_query to get the range on the edge.
161 
162 bool
get_phi_operand(irange & r,tree expr,edge e)163 fur_stmt::get_phi_operand (irange &r, tree expr, edge e)
164 {
165   // Pick up the range of expr from edge E.
166   fur_edge e_src (e, m_query);
167   return e_src.get_operand (r, expr);
168 }
169 
170 // Return relation based from m_stmt.
171 
172 relation_kind
query_relation(tree op1,tree op2)173 fur_stmt::query_relation (tree op1, tree op2)
174 {
175   return m_query->query_relation (m_stmt, op1, op2);
176 }
177 
178 // Instantiate a stmt based fur_source with a GORI object.
179 
180 
fur_depend(gimple * s,gori_compute * gori,range_query * q)181 fur_depend::fur_depend (gimple *s, gori_compute *gori, range_query *q)
182   : fur_stmt (s, q)
183 {
184   gcc_checking_assert (gori);
185   m_gori = gori;
186   // Set relations if there is an oracle in the range_query.
187   // This will enable registering of relationships as they are discovered.
188   m_oracle = q->oracle ();
189 
190 }
191 
192 // Register a relation on a stmt if there is an oracle.
193 
194 void
register_relation(gimple * s,relation_kind k,tree op1,tree op2)195 fur_depend::register_relation (gimple *s, relation_kind k, tree op1, tree op2)
196 {
197   if (m_oracle)
198     m_oracle->register_stmt (s, k, op1, op2);
199 }
200 
201 // Register a relation on an edge if there is an oracle.
202 
203 void
register_relation(edge e,relation_kind k,tree op1,tree op2)204 fur_depend::register_relation (edge e, relation_kind k, tree op1, tree op2)
205 {
206   if (m_oracle)
207     m_oracle->register_edge (e, k, op1, op2);
208 }
209 
210 // This version of fur_source will pick a range up from a list of ranges
211 // supplied by the caller.
212 
213 class fur_list : public fur_source
214 {
215 public:
216   fur_list (irange &r1);
217   fur_list (irange &r1, irange &r2);
218   fur_list (unsigned num, irange *list);
219   virtual bool get_operand (irange &r, tree expr) OVERRIDE;
220   virtual bool get_phi_operand (irange &r, tree expr, edge e) OVERRIDE;
221 private:
222   int_range_max m_local[2];
223   irange *m_list;
224   unsigned m_index;
225   unsigned m_limit;
226 };
227 
228 // One range supplied for unary operations.
229 
fur_list(irange & r1)230 fur_list::fur_list (irange &r1) : fur_source (NULL)
231 {
232   m_list = m_local;
233   m_index = 0;
234   m_limit = 1;
235   m_local[0] = r1;
236 }
237 
238 // Two ranges supplied for binary operations.
239 
fur_list(irange & r1,irange & r2)240 fur_list::fur_list (irange &r1, irange &r2) : fur_source (NULL)
241 {
242   m_list = m_local;
243   m_index = 0;
244   m_limit = 2;
245   m_local[0] = r1;
246   m_local[1] = r2;
247 }
248 
249 // Arbitrary number of ranges in a vector.
250 
fur_list(unsigned num,irange * list)251 fur_list::fur_list (unsigned num, irange *list) : fur_source (NULL)
252 {
253   m_list = list;
254   m_index = 0;
255   m_limit = num;
256 }
257 
258 // Get the next operand from the vector, ensure types are compatible.
259 
260 bool
get_operand(irange & r,tree expr)261 fur_list::get_operand (irange &r, tree expr)
262 {
263   if (m_index >= m_limit)
264     return m_query->range_of_expr (r, expr);
265   r = m_list[m_index++];
266   gcc_checking_assert (range_compatible_p (TREE_TYPE (expr), r.type ()));
267   return true;
268 }
269 
270 // This will simply pick the next operand from the vector.
271 bool
get_phi_operand(irange & r,tree expr,edge e ATTRIBUTE_UNUSED)272 fur_list::get_phi_operand (irange &r, tree expr, edge e ATTRIBUTE_UNUSED)
273 {
274   return get_operand (r, expr);
275 }
276 
277 // Fold stmt S into range R using R1 as the first operand.
278 
279 bool
fold_range(irange & r,gimple * s,irange & r1)280 fold_range (irange &r, gimple *s, irange &r1)
281 {
282   fold_using_range f;
283   fur_list src (r1);
284   return f.fold_stmt (r, s, src);
285 }
286 
287 // Fold stmt S into range R using R1  and R2 as the first two operands.
288 
289 bool
fold_range(irange & r,gimple * s,irange & r1,irange & r2)290 fold_range (irange &r, gimple *s, irange &r1, irange &r2)
291 {
292   fold_using_range f;
293   fur_list src (r1, r2);
294   return f.fold_stmt (r, s, src);
295 }
296 
297 // Fold stmt S into range R using NUM_ELEMENTS from VECTOR as the initial
298 // operands encountered.
299 
300 bool
fold_range(irange & r,gimple * s,unsigned num_elements,irange * vector)301 fold_range (irange &r, gimple *s, unsigned num_elements, irange *vector)
302 {
303   fold_using_range f;
304   fur_list src (num_elements, vector);
305   return f.fold_stmt (r, s, src);
306 }
307 
308 // Fold stmt S into range R using range query Q.
309 
310 bool
fold_range(irange & r,gimple * s,range_query * q)311 fold_range (irange &r, gimple *s, range_query *q)
312 {
313   fold_using_range f;
314   fur_stmt src (s, q);
315   return f.fold_stmt (r, s, src);
316 }
317 
318 // Recalculate stmt S into R using range query Q as if it were on edge ON_EDGE.
319 
320 bool
fold_range(irange & r,gimple * s,edge on_edge,range_query * q)321 fold_range (irange &r, gimple *s, edge on_edge, range_query *q)
322 {
323   fold_using_range f;
324   fur_edge src (on_edge, q);
325   return f.fold_stmt (r, s, src);
326 }
327 
328 // -------------------------------------------------------------------------
329 
330 // Adjust the range for a pointer difference where the operands came
331 // from a memchr.
332 //
333 // This notices the following sequence:
334 //
335 //	def = __builtin_memchr (arg, 0, sz)
336 //	n = def - arg
337 //
338 // The range for N can be narrowed to [0, PTRDIFF_MAX - 1].
339 
340 static void
adjust_pointer_diff_expr(irange & res,const gimple * diff_stmt)341 adjust_pointer_diff_expr (irange &res, const gimple *diff_stmt)
342 {
343   tree op0 = gimple_assign_rhs1 (diff_stmt);
344   tree op1 = gimple_assign_rhs2 (diff_stmt);
345   tree op0_ptype = TREE_TYPE (TREE_TYPE (op0));
346   tree op1_ptype = TREE_TYPE (TREE_TYPE (op1));
347   gimple *call;
348 
349   if (TREE_CODE (op0) == SSA_NAME
350       && TREE_CODE (op1) == SSA_NAME
351       && (call = SSA_NAME_DEF_STMT (op0))
352       && is_gimple_call (call)
353       && gimple_call_builtin_p (call, BUILT_IN_MEMCHR)
354       && TYPE_MODE (op0_ptype) == TYPE_MODE (char_type_node)
355       && TYPE_PRECISION (op0_ptype) == TYPE_PRECISION (char_type_node)
356       && TYPE_MODE (op1_ptype) == TYPE_MODE (char_type_node)
357       && TYPE_PRECISION (op1_ptype) == TYPE_PRECISION (char_type_node)
358       && gimple_call_builtin_p (call, BUILT_IN_MEMCHR)
359       && vrp_operand_equal_p (op1, gimple_call_arg (call, 0))
360       && integer_zerop (gimple_call_arg (call, 1)))
361     {
362       tree max = vrp_val_max (ptrdiff_type_node);
363       unsigned prec = TYPE_PRECISION (TREE_TYPE (max));
364       wide_int wmaxm1 = wi::to_wide (max, prec) - 1;
365       res.intersect (wi::zero (prec), wmaxm1);
366     }
367 }
368 
369 // Adjust the range for an IMAGPART_EXPR.
370 
371 static void
adjust_imagpart_expr(irange & res,const gimple * stmt)372 adjust_imagpart_expr (irange &res, const gimple *stmt)
373 {
374   tree name = TREE_OPERAND (gimple_assign_rhs1 (stmt), 0);
375 
376   if (TREE_CODE (name) != SSA_NAME || !SSA_NAME_DEF_STMT (name))
377     return;
378 
379   gimple *def_stmt = SSA_NAME_DEF_STMT (name);
380   if (is_gimple_call (def_stmt) && gimple_call_internal_p (def_stmt))
381     {
382       switch (gimple_call_internal_fn (def_stmt))
383 	{
384 	case IFN_ADD_OVERFLOW:
385 	case IFN_SUB_OVERFLOW:
386 	case IFN_MUL_OVERFLOW:
387 	case IFN_ATOMIC_COMPARE_EXCHANGE:
388 	  {
389 	    int_range<2> r;
390 	    r.set_varying (boolean_type_node);
391 	    tree type = TREE_TYPE (gimple_assign_lhs (stmt));
392 	    range_cast (r, type);
393 	    res.intersect (r);
394 	  }
395 	default:
396 	  break;
397 	}
398       return;
399     }
400   if (is_gimple_assign (def_stmt)
401       && gimple_assign_rhs_code (def_stmt) == COMPLEX_CST)
402     {
403       tree cst = gimple_assign_rhs1 (def_stmt);
404       if (TREE_CODE (cst) == COMPLEX_CST)
405 	{
406 	  wide_int imag = wi::to_wide (TREE_IMAGPART (cst));
407 	  res.intersect (imag, imag);
408 	}
409     }
410 }
411 
412 // Adjust the range for a REALPART_EXPR.
413 
414 static void
adjust_realpart_expr(irange & res,const gimple * stmt)415 adjust_realpart_expr (irange &res, const gimple *stmt)
416 {
417   tree name = TREE_OPERAND (gimple_assign_rhs1 (stmt), 0);
418 
419   if (TREE_CODE (name) != SSA_NAME)
420     return;
421 
422   gimple *def_stmt = SSA_NAME_DEF_STMT (name);
423   if (!SSA_NAME_DEF_STMT (name))
424     return;
425 
426   if (is_gimple_assign (def_stmt)
427       && gimple_assign_rhs_code (def_stmt) == COMPLEX_CST)
428     {
429       tree cst = gimple_assign_rhs1 (def_stmt);
430       if (TREE_CODE (cst) == COMPLEX_CST)
431 	{
432 	  tree imag = TREE_REALPART (cst);
433 	  int_range<2> tmp (imag, imag);
434 	  res.intersect (tmp);
435 	}
436     }
437 }
438 
439 // This function looks for situations when walking the use/def chains
440 // may provide additonal contextual range information not exposed on
441 // this statement.
442 
443 static void
gimple_range_adjustment(irange & res,const gimple * stmt)444 gimple_range_adjustment (irange &res, const gimple *stmt)
445 {
446   switch (gimple_expr_code (stmt))
447     {
448     case POINTER_DIFF_EXPR:
449       adjust_pointer_diff_expr (res, stmt);
450       return;
451 
452     case IMAGPART_EXPR:
453       adjust_imagpart_expr (res, stmt);
454       return;
455 
456     case REALPART_EXPR:
457       adjust_realpart_expr (res, stmt);
458       return;
459 
460     default:
461       break;
462     }
463 }
464 
465 // Return the base of the RHS of an assignment.
466 
467 static tree
gimple_range_base_of_assignment(const gimple * stmt)468 gimple_range_base_of_assignment (const gimple *stmt)
469 {
470   gcc_checking_assert (gimple_code (stmt) == GIMPLE_ASSIGN);
471   tree op1 = gimple_assign_rhs1 (stmt);
472   if (gimple_assign_rhs_code (stmt) == ADDR_EXPR)
473     return get_base_address (TREE_OPERAND (op1, 0));
474   return op1;
475 }
476 
477 // Return the first operand of this statement if it is a valid operand
478 // supported by ranges, otherwise return NULL_TREE.  Special case is
479 // &(SSA_NAME expr), return the SSA_NAME instead of the ADDR expr.
480 
481 tree
gimple_range_operand1(const gimple * stmt)482 gimple_range_operand1 (const gimple *stmt)
483 {
484   gcc_checking_assert (gimple_range_handler (stmt));
485 
486   switch (gimple_code (stmt))
487     {
488       case GIMPLE_COND:
489 	return gimple_cond_lhs (stmt);
490       case GIMPLE_ASSIGN:
491 	{
492 	  tree base = gimple_range_base_of_assignment (stmt);
493 	  if (base && TREE_CODE (base) == MEM_REF)
494 	    {
495 	      // If the base address is an SSA_NAME, we return it
496 	      // here.  This allows processing of the range of that
497 	      // name, while the rest of the expression is simply
498 	      // ignored.  The code in range_ops will see the
499 	      // ADDR_EXPR and do the right thing.
500 	      tree ssa = TREE_OPERAND (base, 0);
501 	      if (TREE_CODE (ssa) == SSA_NAME)
502 		return ssa;
503 	    }
504 	  return base;
505 	}
506       default:
507 	break;
508     }
509   return NULL;
510 }
511 
512 // Return the second operand of statement STMT, otherwise return NULL_TREE.
513 
514 tree
gimple_range_operand2(const gimple * stmt)515 gimple_range_operand2 (const gimple *stmt)
516 {
517   gcc_checking_assert (gimple_range_handler (stmt));
518 
519   switch (gimple_code (stmt))
520     {
521     case GIMPLE_COND:
522       return gimple_cond_rhs (stmt);
523     case GIMPLE_ASSIGN:
524       if (gimple_num_ops (stmt) >= 3)
525 	return gimple_assign_rhs2 (stmt);
526     default:
527       break;
528     }
529   return NULL_TREE;
530 }
531 
532 // Calculate a range for statement S and return it in R. If NAME is provided it
533 // represents the SSA_NAME on the LHS of the statement. It is only required
534 // if there is more than one lhs/output.  If a range cannot
535 // be calculated, return false.
536 
537 bool
fold_stmt(irange & r,gimple * s,fur_source & src,tree name)538 fold_using_range::fold_stmt (irange &r, gimple *s, fur_source &src, tree name)
539 {
540   bool res = false;
541   // If name and S are specified, make sure it is an LHS of S.
542   gcc_checking_assert (!name || !gimple_get_lhs (s) ||
543 		       name == gimple_get_lhs (s));
544 
545   if (!name)
546     name = gimple_get_lhs (s);
547 
548   // Process addresses.
549   if (gimple_code (s) == GIMPLE_ASSIGN
550       && gimple_assign_rhs_code (s) == ADDR_EXPR)
551     return range_of_address (r, s, src);
552 
553   if (gimple_range_handler (s))
554     res = range_of_range_op (r, s, src);
555   else if (is_a<gphi *>(s))
556     res = range_of_phi (r, as_a<gphi *> (s), src);
557   else if (is_a<gcall *>(s))
558     res = range_of_call (r, as_a<gcall *> (s), src);
559   else if (is_a<gassign *> (s) && gimple_assign_rhs_code (s) == COND_EXPR)
560     res = range_of_cond_expr (r, as_a<gassign *> (s), src);
561 
562   if (!res)
563     {
564       // If no name specified or range is unsupported, bail.
565       if (!name || !gimple_range_ssa_p (name))
566 	return false;
567       // We don't understand the stmt, so return the global range.
568       r = gimple_range_global (name);
569       return true;
570     }
571 
572   if (r.undefined_p ())
573     return true;
574 
575   // We sometimes get compatible types copied from operands, make sure
576   // the correct type is being returned.
577   if (name && TREE_TYPE (name) != r.type ())
578     {
579       gcc_checking_assert (range_compatible_p (r.type (), TREE_TYPE (name)));
580       range_cast (r, TREE_TYPE (name));
581     }
582   return true;
583 }
584 
585 // Calculate a range for range_op statement S and return it in R.  If any
586 // If a range cannot be calculated, return false.
587 
588 bool
range_of_range_op(irange & r,gimple * s,fur_source & src)589 fold_using_range::range_of_range_op (irange &r, gimple *s, fur_source &src)
590 {
591   int_range_max range1, range2;
592   tree type = gimple_range_type (s);
593   if (!type)
594     return false;
595   range_operator *handler = gimple_range_handler (s);
596   gcc_checking_assert (handler);
597 
598   tree lhs = gimple_get_lhs (s);
599   tree op1 = gimple_range_operand1 (s);
600   tree op2 = gimple_range_operand2 (s);
601 
602   if (src.get_operand (range1, op1))
603     {
604       if (!op2)
605 	{
606 	  // Fold range, and register any dependency if available.
607 	  int_range<2> r2 (type);
608 	  handler->fold_range (r, type, range1, r2);
609 	  if (lhs && gimple_range_ssa_p (op1))
610 	    {
611 	      if (src.gori ())
612 		src.gori ()->register_dependency (lhs, op1);
613 	      relation_kind rel;
614 	      rel = handler->lhs_op1_relation (r, range1, range1);
615 	      if (rel != VREL_NONE)
616 		src.register_relation (s, rel, lhs, op1);
617 	    }
618 	}
619       else if (src.get_operand (range2, op2))
620 	{
621 	  relation_kind rel = src.query_relation (op1, op2);
622 	  if (dump_file && (dump_flags & TDF_DETAILS) && rel != VREL_NONE)
623 	    {
624 	      fprintf (dump_file, " folding with relation ");
625 	      print_generic_expr (dump_file, op1, TDF_SLIM);
626 	      print_relation (dump_file, rel);
627 	      print_generic_expr (dump_file, op2, TDF_SLIM);
628 	      fputc ('\n', dump_file);
629 	    }
630 	  // Fold range, and register any dependency if available.
631 	  handler->fold_range (r, type, range1, range2, rel);
632 	  relation_fold_and_or (r, s, src);
633 	  if (lhs)
634 	    {
635 	      if (src.gori ())
636 		{
637 		  src.gori ()->register_dependency (lhs, op1);
638 		  src.gori ()->register_dependency (lhs, op2);
639 		}
640 	      if (gimple_range_ssa_p (op1))
641 		{
642 		  rel = handler->lhs_op1_relation (r, range1, range2);
643 		  if (rel != VREL_NONE)
644 		    src.register_relation (s, rel, lhs, op1);
645 		}
646 	      if (gimple_range_ssa_p (op2))
647 		{
648 		  rel= handler->lhs_op2_relation (r, range1, range2);
649 		  if (rel != VREL_NONE)
650 		    src.register_relation (s, rel, lhs, op2);
651 		}
652 	    }
653 	  // Check for an existing BB, as we maybe asked to fold an
654 	  // artificial statement not in the CFG.
655 	  else if (is_a<gcond *> (s) && gimple_bb (s))
656 	    {
657 	      basic_block bb = gimple_bb (s);
658 	      edge e0 = EDGE_SUCC (bb, 0);
659 	      edge e1 = EDGE_SUCC (bb, 1);
660 
661 	      if (!single_pred_p (e0->dest))
662 		e0 = NULL;
663 	      if (!single_pred_p (e1->dest))
664 		e1 = NULL;
665 	      src.register_outgoing_edges (as_a<gcond *> (s), r, e0, e1);
666 	    }
667 	}
668       else
669 	r.set_varying (type);
670     }
671   else
672     r.set_varying (type);
673   // Make certain range-op adjustments that aren't handled any other way.
674   gimple_range_adjustment (r, s);
675   return true;
676 }
677 
678 // Calculate the range of an assignment containing an ADDR_EXPR.
679 // Return the range in R.
680 // If a range cannot be calculated, set it to VARYING and return true.
681 
682 bool
range_of_address(irange & r,gimple * stmt,fur_source & src)683 fold_using_range::range_of_address (irange &r, gimple *stmt, fur_source &src)
684 {
685   gcc_checking_assert (gimple_code (stmt) == GIMPLE_ASSIGN);
686   gcc_checking_assert (gimple_assign_rhs_code (stmt) == ADDR_EXPR);
687 
688   bool strict_overflow_p;
689   tree expr = gimple_assign_rhs1 (stmt);
690   poly_int64 bitsize, bitpos;
691   tree offset;
692   machine_mode mode;
693   int unsignedp, reversep, volatilep;
694   tree base = get_inner_reference (TREE_OPERAND (expr, 0), &bitsize,
695 				   &bitpos, &offset, &mode, &unsignedp,
696 				   &reversep, &volatilep);
697 
698 
699   if (base != NULL_TREE
700       && TREE_CODE (base) == MEM_REF
701       && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME)
702     {
703       tree ssa = TREE_OPERAND (base, 0);
704       tree lhs = gimple_get_lhs (stmt);
705       if (lhs && gimple_range_ssa_p (ssa) && src.gori ())
706 	src.gori ()->register_dependency (lhs, ssa);
707       gcc_checking_assert (irange::supports_type_p (TREE_TYPE (ssa)));
708       src.get_operand (r, ssa);
709       range_cast (r, TREE_TYPE (gimple_assign_rhs1 (stmt)));
710 
711       poly_offset_int off = 0;
712       bool off_cst = false;
713       if (offset == NULL_TREE || TREE_CODE (offset) == INTEGER_CST)
714 	{
715 	  off = mem_ref_offset (base);
716 	  if (offset)
717 	    off += poly_offset_int::from (wi::to_poly_wide (offset),
718 					  SIGNED);
719 	  off <<= LOG2_BITS_PER_UNIT;
720 	  off += bitpos;
721 	  off_cst = true;
722 	}
723       /* If &X->a is equal to X, the range of X is the result.  */
724       if (off_cst && known_eq (off, 0))
725 	return true;
726       else if (flag_delete_null_pointer_checks
727 	       && !TYPE_OVERFLOW_WRAPS (TREE_TYPE (expr)))
728 	{
729 	  /* For -fdelete-null-pointer-checks -fno-wrapv-pointer we don't
730 	     allow going from non-NULL pointer to NULL.  */
731 	  if (!range_includes_zero_p (&r))
732 	    {
733 	      /* We could here instead adjust r by off >> LOG2_BITS_PER_UNIT
734 		 using POINTER_PLUS_EXPR if off_cst and just fall back to
735 		 this.  */
736 	      r = range_nonzero (TREE_TYPE (gimple_assign_rhs1 (stmt)));
737 	      return true;
738 	    }
739 	}
740       /* If MEM_REF has a "positive" offset, consider it non-NULL
741 	 always, for -fdelete-null-pointer-checks also "negative"
742 	 ones.  Punt for unknown offsets (e.g. variable ones).  */
743       if (!TYPE_OVERFLOW_WRAPS (TREE_TYPE (expr))
744 	  && off_cst
745 	  && known_ne (off, 0)
746 	  && (flag_delete_null_pointer_checks || known_gt (off, 0)))
747 	{
748 	  r = range_nonzero (TREE_TYPE (gimple_assign_rhs1 (stmt)));
749 	  return true;
750 	}
751       r = int_range<2> (TREE_TYPE (gimple_assign_rhs1 (stmt)));
752       return true;
753     }
754 
755   // Handle "= &a".
756   if (tree_single_nonzero_warnv_p (expr, &strict_overflow_p))
757     {
758       r = range_nonzero (TREE_TYPE (gimple_assign_rhs1 (stmt)));
759       return true;
760     }
761 
762   // Otherwise return varying.
763   r = int_range<2> (TREE_TYPE (gimple_assign_rhs1 (stmt)));
764   return true;
765 }
766 
767 // Calculate a range for phi statement S and return it in R.
768 // If a range cannot be calculated, return false.
769 
770 bool
range_of_phi(irange & r,gphi * phi,fur_source & src)771 fold_using_range::range_of_phi (irange &r, gphi *phi, fur_source &src)
772 {
773   tree phi_def = gimple_phi_result (phi);
774   tree type = gimple_range_type (phi);
775   int_range_max arg_range;
776   int_range_max equiv_range;
777   unsigned x;
778 
779   if (!type)
780     return false;
781 
782   // Track if all executable arguments are the same.
783   tree single_arg = NULL_TREE;
784   bool seen_arg = false;
785 
786   // Start with an empty range, unioning in each argument's range.
787   r.set_undefined ();
788   for (x = 0; x < gimple_phi_num_args (phi); x++)
789     {
790       tree arg = gimple_phi_arg_def (phi, x);
791       // An argument that is the same as the def provides no new range.
792       if (arg == phi_def)
793 	continue;
794 
795       edge e = gimple_phi_arg_edge (phi, x);
796 
797       // Get the range of the argument on its edge.
798       src.get_phi_operand (arg_range, arg, e);
799 
800       if (!arg_range.undefined_p ())
801 	{
802 	  // Register potential dependencies for stale value tracking.
803 	  // Likewise, if the incoming PHI argument is equivalent to this
804 	  // PHI definition, it provides no new info.  Accumulate these ranges
805 	  // in case all arguments are equivalences.
806 	  if (src.query ()->query_relation (e, arg, phi_def, false) == EQ_EXPR)
807 	    equiv_range.union_(arg_range);
808 	  else
809 	    r.union_ (arg_range);
810 
811 	  if (gimple_range_ssa_p (arg) && src.gori ())
812 	    src.gori ()->register_dependency (phi_def, arg);
813 
814 	  // Track if all arguments are the same.
815 	  if (!seen_arg)
816 	    {
817 	      seen_arg = true;
818 	      single_arg = arg;
819 	    }
820 	  else if (single_arg != arg)
821 	    single_arg = NULL_TREE;
822 	}
823 
824       // Once the value reaches varying, stop looking.
825       if (r.varying_p () && single_arg == NULL_TREE)
826 	break;
827     }
828 
829     // If all arguments were equivalences, use the equivalence ranges as no
830     // arguments were processed.
831     if (r.undefined_p () && !equiv_range.undefined_p ())
832       r = equiv_range;
833 
834     // If the PHI boils down to a single effective argument, look at it.
835     if (single_arg)
836       {
837 	// Symbolic arguments are equivalences.
838 	if (gimple_range_ssa_p (single_arg))
839 	  src.register_relation (phi, EQ_EXPR, phi_def, single_arg);
840 	else if (src.get_operand (arg_range, single_arg)
841 		 && arg_range.singleton_p ())
842 	  {
843 	    // Numerical arguments that are a constant can be returned as
844 	    // the constant. This can help fold later cases where even this
845 	    // constant might have been UNDEFINED via an unreachable edge.
846 	    r = arg_range;
847 	    return true;
848 	  }
849       }
850 
851   // If SCEV is available, query if this PHI has any knonwn values.
852   if (scev_initialized_p () && !POINTER_TYPE_P (TREE_TYPE (phi_def)))
853     {
854       value_range loop_range;
855       class loop *l = loop_containing_stmt (phi);
856       if (l && loop_outer (l))
857 	{
858 	  range_of_ssa_name_with_loop_info (loop_range, phi_def, l, phi, src);
859 	  if (!loop_range.varying_p ())
860 	    {
861 	      if (dump_file && (dump_flags & TDF_DETAILS))
862 		{
863 		  fprintf (dump_file, "   Loops range found for ");
864 		  print_generic_expr (dump_file, phi_def, TDF_SLIM);
865 		  fprintf (dump_file, ": ");
866 		  loop_range.dump (dump_file);
867 		  fprintf (dump_file, " and calculated range :");
868 		  r.dump (dump_file);
869 		  fprintf (dump_file, "\n");
870 		}
871 	      r.intersect (loop_range);
872 	    }
873 	}
874     }
875 
876   return true;
877 }
878 
879 // Calculate a range for call statement S and return it in R.
880 // If a range cannot be calculated, return false.
881 
882 bool
range_of_call(irange & r,gcall * call,fur_source & src)883 fold_using_range::range_of_call (irange &r, gcall *call, fur_source &src)
884 {
885   tree type = gimple_range_type (call);
886   if (!type)
887     return false;
888 
889   tree lhs = gimple_call_lhs (call);
890   bool strict_overflow_p;
891 
892   if (range_of_builtin_call (r, call, src))
893     ;
894   else if (gimple_stmt_nonnegative_warnv_p (call, &strict_overflow_p))
895     r.set (build_int_cst (type, 0), TYPE_MAX_VALUE (type));
896   else if (gimple_call_nonnull_result_p (call)
897 	   || gimple_call_nonnull_arg (call))
898     r = range_nonzero (type);
899   else
900     r.set_varying (type);
901 
902   // If there is an LHS, intersect that with what is known.
903   if (lhs)
904     {
905       value_range def;
906       def = gimple_range_global (lhs);
907       r.intersect (def);
908     }
909   return true;
910 }
911 
912 // Return the range of a __builtin_ubsan* in CALL and set it in R.
913 // CODE is the type of ubsan call (PLUS_EXPR, MINUS_EXPR or
914 // MULT_EXPR).
915 
916 void
range_of_builtin_ubsan_call(irange & r,gcall * call,tree_code code,fur_source & src)917 fold_using_range::range_of_builtin_ubsan_call (irange &r, gcall *call,
918 					       tree_code code, fur_source &src)
919 {
920   gcc_checking_assert (code == PLUS_EXPR || code == MINUS_EXPR
921 		       || code == MULT_EXPR);
922   tree type = gimple_range_type (call);
923   range_operator *op = range_op_handler (code, type);
924   gcc_checking_assert (op);
925   int_range_max ir0, ir1;
926   tree arg0 = gimple_call_arg (call, 0);
927   tree arg1 = gimple_call_arg (call, 1);
928   src.get_operand (ir0, arg0);
929   src.get_operand (ir1, arg1);
930   // Check for any relation between arg0 and arg1.
931   relation_kind relation = src.query_relation (arg0, arg1);
932 
933   bool saved_flag_wrapv = flag_wrapv;
934   // Pretend the arithmetic is wrapping.  If there is any overflow,
935   // we'll complain, but will actually do wrapping operation.
936   flag_wrapv = 1;
937   op->fold_range (r, type, ir0, ir1, relation);
938   flag_wrapv = saved_flag_wrapv;
939 
940   // If for both arguments vrp_valueize returned non-NULL, this should
941   // have been already folded and if not, it wasn't folded because of
942   // overflow.  Avoid removing the UBSAN_CHECK_* calls in that case.
943   if (r.singleton_p ())
944     r.set_varying (type);
945 }
946 
947 // Return TRUE if we recognize the target character set and return the
948 // range for lower case and upper case letters.
949 
950 static bool
get_letter_range(tree type,irange & lowers,irange & uppers)951 get_letter_range (tree type, irange &lowers, irange &uppers)
952 {
953   // ASCII
954   int a = lang_hooks.to_target_charset ('a');
955   int z = lang_hooks.to_target_charset ('z');
956   int A = lang_hooks.to_target_charset ('A');
957   int Z = lang_hooks.to_target_charset ('Z');
958 
959   if ((z - a == 25) && (Z - A == 25))
960     {
961       lowers = int_range<2> (build_int_cst (type, a), build_int_cst (type, z));
962       uppers = int_range<2> (build_int_cst (type, A), build_int_cst (type, Z));
963       return true;
964     }
965   // Unknown character set.
966   return false;
967 }
968 
969 // For a builtin in CALL, return a range in R if known and return
970 // TRUE.  Otherwise return FALSE.
971 
972 bool
range_of_builtin_call(irange & r,gcall * call,fur_source & src)973 fold_using_range::range_of_builtin_call (irange &r, gcall *call,
974 					 fur_source &src)
975 {
976   combined_fn func = gimple_call_combined_fn (call);
977   if (func == CFN_LAST)
978     return false;
979 
980   tree type = gimple_range_type (call);
981   tree arg;
982   int mini, maxi, zerov = 0, prec;
983   scalar_int_mode mode;
984 
985   switch (func)
986     {
987     case CFN_BUILT_IN_CONSTANT_P:
988       arg = gimple_call_arg (call, 0);
989       if (src.get_operand (r, arg) && r.singleton_p ())
990 	{
991 	  r.set (build_one_cst (type), build_one_cst (type));
992 	  return true;
993 	}
994       if (cfun->after_inlining)
995 	{
996 	  r.set_zero (type);
997 	  // r.equiv_clear ();
998 	  return true;
999 	}
1000       break;
1001 
1002     case CFN_BUILT_IN_TOUPPER:
1003       {
1004 	arg = gimple_call_arg (call, 0);
1005 	// If the argument isn't compatible with the LHS, do nothing.
1006 	if (!range_compatible_p (type, TREE_TYPE (arg)))
1007 	  return false;
1008 	if (!src.get_operand (r, arg))
1009 	  return false;
1010 
1011 	int_range<3> lowers;
1012 	int_range<3> uppers;
1013 	if (!get_letter_range (type, lowers, uppers))
1014 	  return false;
1015 
1016 	// Return the range passed in without any lower case characters,
1017 	// but including all the upper case ones.
1018 	lowers.invert ();
1019 	r.intersect (lowers);
1020 	r.union_ (uppers);
1021 	return true;
1022       }
1023 
1024      case CFN_BUILT_IN_TOLOWER:
1025       {
1026 	arg = gimple_call_arg (call, 0);
1027 	// If the argument isn't compatible with the LHS, do nothing.
1028 	if (!range_compatible_p (type, TREE_TYPE (arg)))
1029 	  return false;
1030 	if (!src.get_operand (r, arg))
1031 	  return false;
1032 
1033 	int_range<3> lowers;
1034 	int_range<3> uppers;
1035 	if (!get_letter_range (type, lowers, uppers))
1036 	  return false;
1037 
1038 	// Return the range passed in without any upper case characters,
1039 	// but including all the lower case ones.
1040 	uppers.invert ();
1041 	r.intersect (uppers);
1042 	r.union_ (lowers);
1043 	return true;
1044       }
1045 
1046     CASE_CFN_FFS:
1047     CASE_CFN_POPCOUNT:
1048       // __builtin_ffs* and __builtin_popcount* return [0, prec].
1049       arg = gimple_call_arg (call, 0);
1050       prec = TYPE_PRECISION (TREE_TYPE (arg));
1051       mini = 0;
1052       maxi = prec;
1053       src.get_operand (r, arg);
1054       // If arg is non-zero, then ffs or popcount are non-zero.
1055       if (!range_includes_zero_p (&r))
1056 	mini = 1;
1057       // If some high bits are known to be zero, decrease the maximum.
1058       if (!r.undefined_p ())
1059 	{
1060 	  if (TYPE_SIGN (r.type ()) == SIGNED)
1061 	    range_cast (r, unsigned_type_for (r.type ()));
1062 	  wide_int max = r.upper_bound ();
1063 	  maxi = wi::floor_log2 (max) + 1;
1064 	}
1065       r.set (build_int_cst (type, mini), build_int_cst (type, maxi));
1066       return true;
1067 
1068     CASE_CFN_PARITY:
1069       r.set (build_zero_cst (type), build_one_cst (type));
1070       return true;
1071 
1072     CASE_CFN_CLZ:
1073       // __builtin_c[lt]z* return [0, prec-1], except when the
1074       // argument is 0, but that is undefined behavior.
1075       //
1076       // For __builtin_c[lt]z* consider argument of 0 always undefined
1077       // behavior, for internal fns depending on C?Z_DEFINED_VALUE_AT_ZERO.
1078       arg = gimple_call_arg (call, 0);
1079       prec = TYPE_PRECISION (TREE_TYPE (arg));
1080       mini = 0;
1081       maxi = prec - 1;
1082       mode = SCALAR_INT_TYPE_MODE (TREE_TYPE (arg));
1083       if (gimple_call_internal_p (call))
1084 	{
1085 	  if (optab_handler (clz_optab, mode) != CODE_FOR_nothing
1086 	      && CLZ_DEFINED_VALUE_AT_ZERO (mode, zerov) == 2)
1087 	    {
1088 	      // Only handle the single common value.
1089 	      if (zerov == prec)
1090 		maxi = prec;
1091 	      else
1092 		// Magic value to give up, unless we can prove arg is non-zero.
1093 		mini = -2;
1094 	    }
1095 	}
1096 
1097       src.get_operand (r, arg);
1098       // From clz of minimum we can compute result maximum.
1099       if (!r.undefined_p ())
1100 	{
1101 	  // From clz of minimum we can compute result maximum.
1102 	  if (wi::gt_p (r.lower_bound (), 0, TYPE_SIGN (r.type ())))
1103 	    {
1104 	      maxi = prec - 1 - wi::floor_log2 (r.lower_bound ());
1105 	      if (mini == -2)
1106 		mini = 0;
1107 	    }
1108 	  else if (!range_includes_zero_p (&r))
1109 	    {
1110 	      mini = 0;
1111 	      maxi = prec - 1;
1112 	    }
1113 	  if (mini == -2)
1114 	    break;
1115 	  // From clz of maximum we can compute result minimum.
1116 	  wide_int max = r.upper_bound ();
1117 	  int newmini = prec - 1 - wi::floor_log2 (max);
1118 	  if (max == 0)
1119 	    {
1120 	      // If CLZ_DEFINED_VALUE_AT_ZERO is 2 with VALUE of prec,
1121 	      // return [prec, prec], otherwise ignore the range.
1122 	      if (maxi == prec)
1123 		mini = prec;
1124 	    }
1125 	  else
1126 	    mini = newmini;
1127 	}
1128       if (mini == -2)
1129 	break;
1130       r.set (build_int_cst (type, mini), build_int_cst (type, maxi));
1131       return true;
1132 
1133     CASE_CFN_CTZ:
1134       // __builtin_ctz* return [0, prec-1], except for when the
1135       // argument is 0, but that is undefined behavior.
1136       //
1137       // For __builtin_ctz* consider argument of 0 always undefined
1138       // behavior, for internal fns depending on CTZ_DEFINED_VALUE_AT_ZERO.
1139       arg = gimple_call_arg (call, 0);
1140       prec = TYPE_PRECISION (TREE_TYPE (arg));
1141       mini = 0;
1142       maxi = prec - 1;
1143       mode = SCALAR_INT_TYPE_MODE (TREE_TYPE (arg));
1144       if (gimple_call_internal_p (call))
1145 	{
1146 	  if (optab_handler (ctz_optab, mode) != CODE_FOR_nothing
1147 	      && CTZ_DEFINED_VALUE_AT_ZERO (mode, zerov) == 2)
1148 	    {
1149 	      // Handle only the two common values.
1150 	      if (zerov == -1)
1151 		mini = -1;
1152 	      else if (zerov == prec)
1153 		maxi = prec;
1154 	      else
1155 		// Magic value to give up, unless we can prove arg is non-zero.
1156 		mini = -2;
1157 	    }
1158 	}
1159       src.get_operand (r, arg);
1160       if (!r.undefined_p ())
1161 	{
1162 	  // If arg is non-zero, then use [0, prec - 1].
1163 	  if (!range_includes_zero_p (&r))
1164 	    {
1165 	      mini = 0;
1166 	      maxi = prec - 1;
1167 	    }
1168 	  // If some high bits are known to be zero, we can decrease
1169 	  // the maximum.
1170 	  wide_int max = r.upper_bound ();
1171 	  if (max == 0)
1172 	    {
1173 	      // Argument is [0, 0].  If CTZ_DEFINED_VALUE_AT_ZERO
1174 	      // is 2 with value -1 or prec, return [-1, -1] or [prec, prec].
1175 	      // Otherwise ignore the range.
1176 	      if (mini == -1)
1177 		maxi = -1;
1178 	      else if (maxi == prec)
1179 		mini = prec;
1180 	    }
1181 	  // If value at zero is prec and 0 is in the range, we can't lower
1182 	  // the upper bound.  We could create two separate ranges though,
1183 	  // [0,floor_log2(max)][prec,prec] though.
1184 	  else if (maxi != prec)
1185 	    maxi = wi::floor_log2 (max);
1186 	}
1187       if (mini == -2)
1188 	break;
1189       r.set (build_int_cst (type, mini), build_int_cst (type, maxi));
1190       return true;
1191 
1192     CASE_CFN_CLRSB:
1193       arg = gimple_call_arg (call, 0);
1194       prec = TYPE_PRECISION (TREE_TYPE (arg));
1195       r.set (build_int_cst (type, 0), build_int_cst (type, prec - 1));
1196       return true;
1197     case CFN_UBSAN_CHECK_ADD:
1198       range_of_builtin_ubsan_call (r, call, PLUS_EXPR, src);
1199       return true;
1200     case CFN_UBSAN_CHECK_SUB:
1201       range_of_builtin_ubsan_call (r, call, MINUS_EXPR, src);
1202       return true;
1203     case CFN_UBSAN_CHECK_MUL:
1204       range_of_builtin_ubsan_call (r, call, MULT_EXPR, src);
1205       return true;
1206 
1207     case CFN_GOACC_DIM_SIZE:
1208     case CFN_GOACC_DIM_POS:
1209       // Optimizing these two internal functions helps the loop
1210       // optimizer eliminate outer comparisons.  Size is [1,N]
1211       // and pos is [0,N-1].
1212       {
1213 	bool is_pos = func == CFN_GOACC_DIM_POS;
1214 	int axis = oacc_get_ifn_dim_arg (call);
1215 	int size = oacc_get_fn_dim_size (current_function_decl, axis);
1216 	if (!size)
1217 	  // If it's dynamic, the backend might know a hardware limitation.
1218 	  size = targetm.goacc.dim_limit (axis);
1219 
1220 	r.set (build_int_cst (type, is_pos ? 0 : 1),
1221 	       size
1222 	       ? build_int_cst (type, size - is_pos) : vrp_val_max (type));
1223 	return true;
1224       }
1225 
1226     case CFN_BUILT_IN_STRLEN:
1227       if (tree lhs = gimple_call_lhs (call))
1228 	if (ptrdiff_type_node
1229 	    && (TYPE_PRECISION (ptrdiff_type_node)
1230 		== TYPE_PRECISION (TREE_TYPE (lhs))))
1231 	  {
1232 	    tree type = TREE_TYPE (lhs);
1233 	    tree max = vrp_val_max (ptrdiff_type_node);
1234 	    wide_int wmax
1235 	      = wi::to_wide (max, TYPE_PRECISION (TREE_TYPE (max)));
1236 	    tree range_min = build_zero_cst (type);
1237 	    // To account for the terminating NULL, the maximum length
1238 	    // is one less than the maximum array size, which in turn
1239 	    // is one less than PTRDIFF_MAX (or SIZE_MAX where it's
1240 	    // smaller than the former type).
1241 	    // FIXME: Use max_object_size() - 1 here.
1242 	    tree range_max = wide_int_to_tree (type, wmax - 2);
1243 	    r.set (range_min, range_max);
1244 	    return true;
1245 	  }
1246       break;
1247     default:
1248       break;
1249     }
1250   return false;
1251 }
1252 
1253 
1254 // Calculate a range for COND_EXPR statement S and return it in R.
1255 // If a range cannot be calculated, return false.
1256 
1257 bool
range_of_cond_expr(irange & r,gassign * s,fur_source & src)1258 fold_using_range::range_of_cond_expr  (irange &r, gassign *s, fur_source &src)
1259 {
1260   int_range_max cond_range, range1, range2;
1261   tree cond = gimple_assign_rhs1 (s);
1262   tree op1 = gimple_assign_rhs2 (s);
1263   tree op2 = gimple_assign_rhs3 (s);
1264 
1265   tree type = gimple_range_type (s);
1266   if (!type)
1267     return false;
1268 
1269   gcc_checking_assert (gimple_assign_rhs_code (s) == COND_EXPR);
1270   gcc_checking_assert (range_compatible_p (TREE_TYPE (op1), TREE_TYPE (op2)));
1271   src.get_operand (cond_range, cond);
1272   src.get_operand (range1, op1);
1273   src.get_operand (range2, op2);
1274 
1275   // Try to see if there is a dependence between the COND and either operand
1276   if (src.gori ())
1277     if (src.gori ()->condexpr_adjust (range1, range2, s, cond, op1, op2, src))
1278       if (dump_file && (dump_flags & TDF_DETAILS))
1279 	{
1280 	  fprintf (dump_file, "Possible COND_EXPR adjustment. Range op1 : ");
1281 	  range1.dump(dump_file);
1282 	  fprintf (dump_file, " and Range op2: ");
1283 	  range2.dump(dump_file);
1284 	  fprintf (dump_file, "\n");
1285 	}
1286 
1287   // If the condition is known, choose the appropriate expression.
1288   if (cond_range.singleton_p ())
1289     {
1290       // False, pick second operand.
1291       if (cond_range.zero_p ())
1292 	r = range2;
1293       else
1294 	r = range1;
1295     }
1296   else
1297     {
1298       r = range1;
1299       r.union_ (range2);
1300     }
1301   gcc_checking_assert (r.undefined_p ()
1302 		       || range_compatible_p (r.type (), type));
1303   return true;
1304 }
1305 
1306 // If SCEV has any information about phi node NAME, return it as a range in R.
1307 
1308 void
range_of_ssa_name_with_loop_info(irange & r,tree name,class loop * l,gphi * phi,fur_source & src)1309 fold_using_range::range_of_ssa_name_with_loop_info (irange &r, tree name,
1310 						    class loop *l, gphi *phi,
1311 						    fur_source &src)
1312 {
1313   gcc_checking_assert (TREE_CODE (name) == SSA_NAME);
1314   tree min, max, type = TREE_TYPE (name);
1315   if (bounds_of_var_in_loop (&min, &max, src.query (), l, phi, name))
1316     {
1317       if (TREE_CODE (min) != INTEGER_CST)
1318 	{
1319 	  if (src.query ()->range_of_expr (r, min, phi) && !r.undefined_p ())
1320 	    min = wide_int_to_tree (type, r.lower_bound ());
1321 	  else
1322 	    min = vrp_val_min (type);
1323 	}
1324       if (TREE_CODE (max) != INTEGER_CST)
1325 	{
1326 	  if (src.query ()->range_of_expr (r, max, phi) && !r.undefined_p ())
1327 	    max = wide_int_to_tree (type, r.upper_bound ());
1328 	  else
1329 	    max = vrp_val_max (type);
1330 	}
1331       r.set (min, max);
1332     }
1333   else
1334     r.set_varying (type);
1335 }
1336 
1337 // -----------------------------------------------------------------------
1338 
1339 // Check if an && or || expression can be folded based on relations. ie
1340 //   c_2 = a_6 > b_7
1341 //   c_3 = a_6 < b_7
1342 //   c_4 = c_2 && c_3
1343 // c_2 and c_3 can never be true at the same time,
1344 // Therefore c_4 can always resolve to false based purely on the relations.
1345 
1346 void
relation_fold_and_or(irange & lhs_range,gimple * s,fur_source & src)1347 fold_using_range::relation_fold_and_or (irange& lhs_range, gimple *s,
1348 					fur_source &src)
1349 {
1350   // No queries or already folded.
1351   if (!src.gori () || !src.query ()->oracle () || lhs_range.singleton_p ())
1352     return;
1353 
1354   // Only care about AND and OR expressions.
1355   enum tree_code code = gimple_expr_code (s);
1356   bool is_and = false;
1357   if (code == BIT_AND_EXPR || code == TRUTH_AND_EXPR)
1358     is_and = true;
1359   else if (code != BIT_IOR_EXPR && code != TRUTH_OR_EXPR)
1360     return;
1361 
1362   tree lhs = gimple_get_lhs (s);
1363   tree ssa1 = gimple_range_ssa_p (gimple_range_operand1 (s));
1364   tree ssa2 = gimple_range_ssa_p (gimple_range_operand2 (s));
1365 
1366   // Deal with || and && only when there is a full set of symbolics.
1367   if (!lhs || !ssa1 || !ssa2
1368       || (TREE_CODE (TREE_TYPE (lhs)) != BOOLEAN_TYPE)
1369       || (TREE_CODE (TREE_TYPE (ssa1)) != BOOLEAN_TYPE)
1370       || (TREE_CODE (TREE_TYPE (ssa2)) != BOOLEAN_TYPE))
1371     return;
1372 
1373   // Now we know its a boolean AND or OR expression with boolean operands.
1374   // Ideally we search dependencies for common names, and see what pops out.
1375   // until then, simply try to resolve direct dependencies.
1376 
1377   gimple *ssa1_stmt = SSA_NAME_DEF_STMT (ssa1);
1378   gimple *ssa2_stmt = SSA_NAME_DEF_STMT (ssa2);
1379 
1380   range_operator *handler1 = gimple_range_handler (SSA_NAME_DEF_STMT (ssa1));
1381   range_operator *handler2 = gimple_range_handler (SSA_NAME_DEF_STMT (ssa2));
1382 
1383   // If either handler is not present, no relation can be found.
1384   if (!handler1 || !handler2)
1385     return;
1386 
1387   // Both stmts will need to have 2 ssa names in the stmt.
1388   tree ssa1_dep1 = gimple_range_ssa_p (gimple_range_operand1 (ssa1_stmt));
1389   tree ssa1_dep2 = gimple_range_ssa_p (gimple_range_operand2 (ssa1_stmt));
1390   tree ssa2_dep1 = gimple_range_ssa_p (gimple_range_operand1 (ssa2_stmt));
1391   tree ssa2_dep2 = gimple_range_ssa_p (gimple_range_operand2 (ssa2_stmt));
1392 
1393   if (!ssa1_dep1 || !ssa1_dep2 || !ssa2_dep1 || !ssa2_dep2)
1394     return;
1395 
1396   // Make sure they are the same dependencies, and detect the order of the
1397   // relationship.
1398   bool reverse_op2 = true;
1399   if (ssa1_dep1 == ssa2_dep1 && ssa1_dep2 == ssa2_dep2)
1400     reverse_op2 = false;
1401   else if (ssa1_dep1 != ssa2_dep2 || ssa1_dep2 != ssa2_dep1)
1402     return;
1403 
1404   int_range<2> bool_one (boolean_true_node, boolean_true_node);
1405 
1406   relation_kind relation1 = handler1->op1_op2_relation (bool_one);
1407   relation_kind relation2 = handler2->op1_op2_relation (bool_one);
1408   if (relation1 == VREL_NONE || relation2 == VREL_NONE)
1409     return;
1410 
1411   if (reverse_op2)
1412     relation2 = relation_negate (relation2);
1413 
1414   // x && y is false if the relation intersection of the true cases is NULL.
1415   if (is_and && relation_intersect (relation1, relation2) == VREL_EMPTY)
1416     lhs_range = int_range<2> (boolean_false_node, boolean_false_node);
1417   // x || y is true if the union of the true cases is NO-RELATION..
1418   // ie, one or the other being true covers the full range of possibilties.
1419   else if (!is_and && relation_union (relation1, relation2) == VREL_NONE)
1420     lhs_range = bool_one;
1421   else
1422     return;
1423 
1424   range_cast (lhs_range, TREE_TYPE (lhs));
1425   if (dump_file && (dump_flags & TDF_DETAILS))
1426     {
1427       fprintf (dump_file, "  Relation adjustment: ");
1428       print_generic_expr (dump_file, ssa1, TDF_SLIM);
1429       fprintf (dump_file, "  and ");
1430       print_generic_expr (dump_file, ssa2, TDF_SLIM);
1431       fprintf (dump_file, "  combine to produce ");
1432       lhs_range.dump (dump_file);
1433       fputc ('\n', dump_file);
1434     }
1435 
1436   return;
1437 }
1438 
1439 // Register any outgoing edge relations from a conditional branch.
1440 
1441 void
register_outgoing_edges(gcond * s,irange & lhs_range,edge e0,edge e1)1442 fur_source::register_outgoing_edges (gcond *s, irange &lhs_range, edge e0, edge e1)
1443 {
1444   int_range_max r;
1445   int_range<2> e0_range, e1_range;
1446   tree name;
1447   range_operator *handler;
1448   basic_block bb = gimple_bb (s);
1449 
1450   if (e0)
1451     {
1452       // If this edge is never taken, ignore it.
1453       gcond_edge_range (e0_range, e0);
1454       e0_range.intersect (lhs_range);
1455       if (e0_range.undefined_p ())
1456 	e0 = NULL;
1457     }
1458 
1459 
1460   if (e1)
1461     {
1462       // If this edge is never taken, ignore it.
1463       gcond_edge_range (e1_range, e1);
1464       e1_range.intersect (lhs_range);
1465       if (e1_range.undefined_p ())
1466 	e1 = NULL;
1467     }
1468 
1469   if (!e0 && !e1)
1470     return;
1471 
1472   // First, register the gcond itself.  This will catch statements like
1473   // if (a_2 < b_5)
1474   tree ssa1 = gimple_range_ssa_p (gimple_range_operand1 (s));
1475   tree ssa2 = gimple_range_ssa_p (gimple_range_operand2 (s));
1476   if (ssa1 && ssa2)
1477     {
1478       handler = gimple_range_handler (s);
1479       gcc_checking_assert (handler);
1480       if (e0)
1481 	{
1482 	  relation_kind relation = handler->op1_op2_relation (e0_range);
1483 	  if (relation != VREL_NONE)
1484 	    register_relation (e0, relation, ssa1, ssa2);
1485 	}
1486       if (e1)
1487 	{
1488 	  relation_kind relation = handler->op1_op2_relation (e1_range);
1489 	  if (relation != VREL_NONE)
1490 	    register_relation (e1, relation, ssa1, ssa2);
1491 	}
1492     }
1493 
1494   // Outgoing relations of GORI exports require a gori engine.
1495   if (!gori ())
1496     return;
1497 
1498   // Now look for other relations in the exports.  This will find stmts
1499   // leading to the condition such as:
1500   // c_2 = a_4 < b_7
1501   // if (c_2)
1502   FOR_EACH_GORI_EXPORT_NAME (*(gori ()), bb, name)
1503     {
1504       if (TREE_CODE (TREE_TYPE (name)) != BOOLEAN_TYPE)
1505 	continue;
1506       gimple *stmt = SSA_NAME_DEF_STMT (name);
1507       handler = gimple_range_handler (stmt);
1508       if (!handler)
1509 	continue;
1510       tree ssa1 = gimple_range_ssa_p (gimple_range_operand1 (stmt));
1511       tree ssa2 = gimple_range_ssa_p (gimple_range_operand2 (stmt));
1512       if (ssa1 && ssa2)
1513 	{
1514 	  if (e0 && gori ()->outgoing_edge_range_p (r, e0, name, *m_query)
1515 	      && r.singleton_p ())
1516 	    {
1517 	      relation_kind relation = handler->op1_op2_relation (r);
1518 	      if (relation != VREL_NONE)
1519 		register_relation (e0, relation, ssa1, ssa2);
1520 	    }
1521 	  if (e1 && gori ()->outgoing_edge_range_p (r, e1, name, *m_query)
1522 	      && r.singleton_p ())
1523 	    {
1524 	      relation_kind relation = handler->op1_op2_relation (r);
1525 	      if (relation != VREL_NONE)
1526 		register_relation (e1, relation, ssa1, ssa2);
1527 	    }
1528 	}
1529     }
1530 }
1531