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simplify_expr.cpp
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1/*******************************************************************\
2
3Module:
4
5Author: Daniel Kroening, kroening@kroening.com
6
7\*******************************************************************/
8
9#include "simplify_expr.h"
10
11#include <algorithm>
12
13#include "bitvector_expr.h"
14#include "byte_operators.h"
15#include "c_types.h"
16#include "config.h"
17#include "expr_util.h"
18#include "fixedbv.h"
19#include "floatbv_expr.h"
20#include "invariant.h"
21#include "mathematical_expr.h"
22#include "namespace.h"
23#include "pointer_expr.h"
24#include "pointer_offset_size.h"
25#include "pointer_offset_sum.h"
26#include "rational.h"
27#include "rational_tools.h"
28#include "simplify_utils.h"
29#include "std_expr.h"
30#include "string_expr.h"
31
32// #define DEBUGX
33
34#ifdef DEBUGX
35#include "format_expr.h"
36#include <iostream>
37#endif
38
39#include "simplify_expr_class.h"
40
41// #define USE_CACHE
42
43#ifdef USE_CACHE
44struct simplify_expr_cachet
45{
46public:
47 #if 1
48 typedef std::unordered_map<
50 #else
51 typedef std::unordered_map<exprt, exprt, irep_hash> containert;
52 #endif
53
54 containert container_normal;
55
56 containert &container()
57 {
58 return container_normal;
59 }
60};
61
62simplify_expr_cachet simplify_expr_cache;
63#endif
64
66{
67 if(expr.op().is_constant())
68 {
69 const typet &type = to_unary_expr(expr).op().type();
70
71 if(type.id()==ID_floatbv)
72 {
74 value.set_sign(false);
75 return value.to_expr();
76 }
77 else if(type.id()==ID_signedbv ||
78 type.id()==ID_unsignedbv)
79 {
80 auto value = numeric_cast<mp_integer>(to_unary_expr(expr).op());
81 if(value.has_value())
82 {
83 if(*value >= 0)
84 {
85 return to_unary_expr(expr).op();
86 }
87 else
88 {
89 value->negate();
90 return from_integer(*value, type);
91 }
92 }
93 }
94 }
95
96 return unchanged(expr);
97}
98
100{
101 if(expr.op().is_constant())
102 {
103 const typet &type = expr.op().type();
104
105 if(type.id()==ID_floatbv)
106 {
107 ieee_floatt value(to_constant_expr(expr.op()));
108 return make_boolean_expr(value.get_sign());
109 }
110 else if(type.id()==ID_signedbv ||
111 type.id()==ID_unsignedbv)
112 {
113 const auto value = numeric_cast<mp_integer>(expr.op());
114 if(value.has_value())
115 {
116 return make_boolean_expr(*value >= 0);
117 }
118 }
119 }
120
121 return unchanged(expr);
122}
123
126{
127 const exprt &op = expr.op();
128
129 if(op.is_constant())
130 {
131 const typet &op_type = op.type();
132
133 if(op_type.id() == ID_signedbv || op_type.id() == ID_unsignedbv)
134 {
135 const auto width = to_bitvector_type(op_type).get_width();
136 const auto &value = to_constant_expr(op).get_value();
137 std::size_t result = 0;
138
139 for(std::size_t i = 0; i < width; i++)
140 if(get_bvrep_bit(value, width, i))
141 result++;
142
143 return from_integer(result, expr.type());
144 }
145 }
146
147 return unchanged(expr);
148}
149
152{
153 const bool is_little_endian =
155
156 const auto const_bits_opt = expr2bits(expr.op(), is_little_endian, ns);
157
158 if(!const_bits_opt.has_value())
159 return unchanged(expr);
160
161 std::size_t n_leading_zeros =
162 is_little_endian ? const_bits_opt->rfind('1') : const_bits_opt->find('1');
163 if(n_leading_zeros == std::string::npos)
164 {
165 if(!expr.zero_permitted())
166 return unchanged(expr);
167
168 n_leading_zeros = const_bits_opt->size();
169 }
170 else if(is_little_endian)
171 n_leading_zeros = const_bits_opt->size() - n_leading_zeros - 1;
172
173 return from_integer(n_leading_zeros, expr.type());
174}
175
178{
179 const bool is_little_endian =
181
182 const auto const_bits_opt = expr2bits(expr.op(), is_little_endian, ns);
183
184 if(!const_bits_opt.has_value())
185 return unchanged(expr);
186
187 std::size_t n_trailing_zeros =
188 is_little_endian ? const_bits_opt->find('1') : const_bits_opt->rfind('1');
189 if(n_trailing_zeros == std::string::npos)
190 {
191 if(!expr.zero_permitted())
192 return unchanged(expr);
193
194 n_trailing_zeros = const_bits_opt->size();
195 }
196 else if(!is_little_endian)
197 n_trailing_zeros = const_bits_opt->size() - n_trailing_zeros - 1;
198
199 return from_integer(n_trailing_zeros, expr.type());
200}
201
204{
205 const bool is_little_endian =
207
208 const auto const_bits_opt = expr2bits(expr.op(), is_little_endian, ns);
209
210 if(!const_bits_opt.has_value())
211 return unchanged(expr);
212
213 std::size_t first_one_bit =
214 is_little_endian ? const_bits_opt->find('1') : const_bits_opt->rfind('1');
215 if(first_one_bit == std::string::npos)
216 first_one_bit = 0;
217 else if(is_little_endian)
218 ++first_one_bit;
219 else
220 first_one_bit = const_bits_opt->size() - first_one_bit;
221
222 return from_integer(first_one_bit, expr.type());
223}
224
230 const function_application_exprt &expr,
231 const namespacet &ns)
232{
233 const refined_string_exprt &s1 = to_string_expr(expr.arguments().at(0));
234 const auto s1_data_opt = try_get_string_data_array(s1.content(), ns);
235
236 if(!s1_data_opt)
237 return simplify_exprt::unchanged(expr);
238
239 const array_exprt &s1_data = s1_data_opt->get();
240 const refined_string_exprt &s2 = to_string_expr(expr.arguments().at(1));
241 const auto s2_data_opt = try_get_string_data_array(s2.content(), ns);
242
243 if(!s2_data_opt)
244 return simplify_exprt::unchanged(expr);
245
246 const array_exprt &s2_data = s2_data_opt->get();
247 const bool res = s2_data.operands().size() <= s1_data.operands().size() &&
248 std::equal(
249 s2_data.operands().rbegin(),
250 s2_data.operands().rend(),
251 s1_data.operands().rbegin());
252
253 return from_integer(res ? 1 : 0, expr.type());
254}
255
258 const function_application_exprt &expr,
259 const namespacet &ns)
260{
261 // We want to get both arguments of any starts-with comparison, and
262 // trace them back to the actual string instance. All variables on the
263 // way must be constant for us to be sure this will work.
264 auto &first_argument = to_string_expr(expr.arguments().at(0));
265 auto &second_argument = to_string_expr(expr.arguments().at(1));
266
267 const auto first_value_opt =
268 try_get_string_data_array(first_argument.content(), ns);
269
270 if(!first_value_opt)
271 {
272 return simplify_exprt::unchanged(expr);
273 }
274
275 const array_exprt &first_value = first_value_opt->get();
276
277 const auto second_value_opt =
278 try_get_string_data_array(second_argument.content(), ns);
279
280 if(!second_value_opt)
281 {
282 return simplify_exprt::unchanged(expr);
283 }
284
285 const array_exprt &second_value = second_value_opt->get();
286
287 // Is our 'contains' array directly contained in our target.
288 const bool includes =
289 std::search(
290 first_value.operands().begin(),
291 first_value.operands().end(),
292 second_value.operands().begin(),
293 second_value.operands().end()) != first_value.operands().end();
294
295 return from_integer(includes ? 1 : 0, expr.type());
296}
297
303 const function_application_exprt &expr,
304 const namespacet &ns)
305{
306 const function_application_exprt &function_app =
308 const refined_string_exprt &s =
309 to_string_expr(function_app.arguments().at(0));
310
311 if(!s.length().is_constant())
312 return simplify_exprt::unchanged(expr);
313
314 const auto numeric_length =
316
317 return from_integer(numeric_length == 0 ? 1 : 0, expr.type());
318}
319
328 const function_application_exprt &expr,
329 const namespacet &ns)
330{
331 const refined_string_exprt &s1 = to_string_expr(expr.arguments().at(0));
332 const auto s1_data_opt = try_get_string_data_array(s1.content(), ns);
333
334 if(!s1_data_opt)
335 return simplify_exprt::unchanged(expr);
336
337 const refined_string_exprt &s2 = to_string_expr(expr.arguments().at(1));
338 const auto s2_data_opt = try_get_string_data_array(s2.content(), ns);
339
340 if(!s2_data_opt)
341 return simplify_exprt::unchanged(expr);
342
343 const array_exprt &s1_data = s1_data_opt->get();
344 const array_exprt &s2_data = s2_data_opt->get();
345
346 if(s1_data.operands() == s2_data.operands())
347 return from_integer(0, expr.type());
348
349 const mp_integer s1_size = s1_data.operands().size();
350 const mp_integer s2_size = s2_data.operands().size();
351 const bool first_shorter = s1_size < s2_size;
352 const exprt::operandst &ops1 =
353 first_shorter ? s1_data.operands() : s2_data.operands();
354 const exprt::operandst &ops2 =
355 first_shorter ? s2_data.operands() : s1_data.operands();
356 auto it_pair = std::mismatch(ops1.begin(), ops1.end(), ops2.begin());
357
358 if(it_pair.first == ops1.end())
359 return from_integer(s1_size - s2_size, expr.type());
360
361 const mp_integer char1 =
363 const mp_integer char2 =
365
366 return from_integer(
367 first_shorter ? char1 - char2 : char2 - char1, expr.type());
368}
369
377 const function_application_exprt &expr,
378 const namespacet &ns,
379 const bool search_from_end)
380{
381 std::size_t starting_index = 0;
382
383 // Determine starting index for the comparison (if given)
384 if(expr.arguments().size() == 3)
385 {
386 auto &starting_index_expr = expr.arguments().at(2);
387
388 if(!starting_index_expr.is_constant())
389 {
390 return simplify_exprt::unchanged(expr);
391 }
392
393 const mp_integer idx =
394 numeric_cast_v<mp_integer>(to_constant_expr(starting_index_expr));
395
396 // Negative indices are treated like 0
397 if(idx > 0)
398 {
399 starting_index = numeric_cast_v<std::size_t>(idx);
400 }
401 }
402
403 const refined_string_exprt &s1 = to_string_expr(expr.arguments().at(0));
404
405 const auto s1_data_opt = try_get_string_data_array(s1.content(), ns);
406
407 if(!s1_data_opt)
408 {
409 return simplify_exprt::unchanged(expr);
410 }
411
412 const array_exprt &s1_data = s1_data_opt->get();
413
414 const auto search_string_size = s1_data.operands().size();
415 if(starting_index >= search_string_size)
416 {
417 return from_integer(-1, expr.type());
418 }
419
420 unsigned long starting_offset =
421 starting_index > 0 ? (search_string_size - 1) - starting_index : 0;
423 {
424 // Second argument is a string
425
426 const refined_string_exprt &s2 = to_string_expr(expr.arguments().at(1));
427
428 const auto s2_data_opt = try_get_string_data_array(s2.content(), ns);
429
430 if(!s2_data_opt)
431 {
432 return simplify_exprt::unchanged(expr);
433 }
434
435 const array_exprt &s2_data = s2_data_opt->get();
436
437 // Searching for empty string is a special case and is simply the
438 // "always found at the first searched position. This needs to take into
439 // account starting position and if you're starting from the beginning or
440 // end.
441 if(s2_data.operands().empty())
442 return from_integer(
443 search_from_end
444 ? starting_index > 0 ? starting_index : search_string_size
445 : 0,
446 expr.type());
447
448 if(search_from_end)
449 {
450 auto end = std::prev(s1_data.operands().end(), starting_offset);
451 auto it = std::find_end(
452 s1_data.operands().begin(),
453 end,
454 s2_data.operands().begin(),
455 s2_data.operands().end());
456 if(it != end)
457 return from_integer(
458 std::distance(s1_data.operands().begin(), it), expr.type());
459 }
460 else
461 {
462 auto it = std::search(
463 std::next(s1_data.operands().begin(), starting_index),
464 s1_data.operands().end(),
465 s2_data.operands().begin(),
466 s2_data.operands().end());
467
468 if(it != s1_data.operands().end())
469 return from_integer(
470 std::distance(s1_data.operands().begin(), it), expr.type());
471 }
472 }
473 else if(expr.arguments().at(1).is_constant())
474 {
475 // Second argument is a constant character
476
477 const constant_exprt &c1 = to_constant_expr(expr.arguments().at(1));
478 const auto c1_val = numeric_cast_v<mp_integer>(c1);
479
480 auto pred = [&](const exprt &c2) {
481 const auto c2_val = numeric_cast_v<mp_integer>(to_constant_expr(c2));
482
483 return c1_val == c2_val;
484 };
485
486 if(search_from_end)
487 {
488 auto it = std::find_if(
489 std::next(s1_data.operands().rbegin(), starting_offset),
490 s1_data.operands().rend(),
491 pred);
492 if(it != s1_data.operands().rend())
493 return from_integer(
494 std::distance(s1_data.operands().begin(), it.base() - 1),
495 expr.type());
496 }
497 else
498 {
499 auto it = std::find_if(
500 std::next(s1_data.operands().begin(), starting_index),
501 s1_data.operands().end(),
502 pred);
503 if(it != s1_data.operands().end())
504 return from_integer(
505 std::distance(s1_data.operands().begin(), it), expr.type());
506 }
507 }
508 else
509 {
510 return simplify_exprt::unchanged(expr);
511 }
512
513 return from_integer(-1, expr.type());
514}
515
522 const function_application_exprt &expr,
523 const namespacet &ns)
524{
525 if(!expr.arguments().at(1).is_constant())
526 {
527 return simplify_exprt::unchanged(expr);
528 }
529
530 const auto &index = to_constant_expr(expr.arguments().at(1));
531
532 const refined_string_exprt &s = to_string_expr(expr.arguments().at(0));
533
534 const auto char_seq_opt = try_get_string_data_array(s.content(), ns);
535
536 if(!char_seq_opt)
537 {
538 return simplify_exprt::unchanged(expr);
539 }
540
541 const array_exprt &char_seq = char_seq_opt->get();
542
543 const auto i_opt = numeric_cast<std::size_t>(index);
544
545 if(!i_opt || *i_opt >= char_seq.operands().size())
546 {
547 return simplify_exprt::unchanged(expr);
548 }
549
550 const auto &c = to_constant_expr(char_seq.operands().at(*i_opt));
551
552 if(c.type() != expr.type())
553 {
554 return simplify_exprt::unchanged(expr);
555 }
556
557 return c;
558}
559
562{
563 auto &operands = string_data.operands();
564 for(auto &operand : operands)
565 {
566 auto &constant_value = to_constant_expr(operand);
567 auto character = numeric_cast_v<unsigned int>(constant_value);
568
569 // Can't guarantee matches against non-ASCII characters.
570 if(character >= 128)
571 return false;
572
573 if(isalpha(character))
574 {
575 if(isupper(character))
576 constant_value =
577 from_integer(tolower(character), constant_value.type());
578 }
579 }
580
581 return true;
582}
583
590 const function_application_exprt &expr,
591 const namespacet &ns)
592{
593 // We want to get both arguments of any starts-with comparison, and
594 // trace them back to the actual string instance. All variables on the
595 // way must be constant for us to be sure this will work.
596 auto &first_argument = to_string_expr(expr.arguments().at(0));
597 auto &second_argument = to_string_expr(expr.arguments().at(1));
598
599 const auto first_value_opt =
600 try_get_string_data_array(first_argument.content(), ns);
601
602 if(!first_value_opt)
603 {
604 return simplify_exprt::unchanged(expr);
605 }
606
607 array_exprt first_value = first_value_opt->get();
608
609 const auto second_value_opt =
610 try_get_string_data_array(second_argument.content(), ns);
611
612 if(!second_value_opt)
613 {
614 return simplify_exprt::unchanged(expr);
615 }
616
617 array_exprt second_value = second_value_opt->get();
618
619 // Just lower-case both expressions.
620 if(
621 !lower_case_string_expression(first_value) ||
622 !lower_case_string_expression(second_value))
623 return simplify_exprt::unchanged(expr);
624
625 bool is_equal = first_value == second_value;
626 return from_integer(is_equal ? 1 : 0, expr.type());
627}
628
635 const function_application_exprt &expr,
636 const namespacet &ns)
637{
638 // We want to get both arguments of any starts-with comparison, and
639 // trace them back to the actual string instance. All variables on the
640 // way must be constant for us to be sure this will work.
641 auto &first_argument = to_string_expr(expr.arguments().at(0));
642 auto &second_argument = to_string_expr(expr.arguments().at(1));
643
644 const auto first_value_opt =
645 try_get_string_data_array(first_argument.content(), ns);
646
647 if(!first_value_opt)
648 {
649 return simplify_exprt::unchanged(expr);
650 }
651
652 const array_exprt &first_value = first_value_opt->get();
653
654 const auto second_value_opt =
655 try_get_string_data_array(second_argument.content(), ns);
656
657 if(!second_value_opt)
658 {
659 return simplify_exprt::unchanged(expr);
660 }
661
662 const array_exprt &second_value = second_value_opt->get();
663
664 mp_integer offset_int = 0;
665 if(expr.arguments().size() == 3)
666 {
667 auto &offset = expr.arguments()[2];
668 if(!offset.is_constant())
669 return simplify_exprt::unchanged(expr);
670 offset_int = numeric_cast_v<mp_integer>(to_constant_expr(offset));
671 }
672
673 // test whether second_value is a prefix of first_value
674 bool is_prefix =
675 offset_int >= 0 && mp_integer(first_value.operands().size()) >=
676 offset_int + second_value.operands().size();
677 if(is_prefix)
678 {
679 exprt::operandst::const_iterator second_it =
680 second_value.operands().begin();
681 for(const auto &first_op : first_value.operands())
682 {
683 if(offset_int > 0)
684 --offset_int;
685 else if(second_it == second_value.operands().end())
686 break;
687 else if(first_op != *second_it)
688 {
689 is_prefix = false;
690 break;
691 }
692 else
693 ++second_it;
694 }
695 }
696
697 return from_integer(is_prefix ? 1 : 0, expr.type());
698}
699
701 const function_application_exprt &expr)
702{
703 if(expr.function().id() == ID_lambda)
704 {
705 // expand the function application
706 return to_lambda_expr(expr.function()).application(expr.arguments());
707 }
708
709 if(expr.function().id() != ID_symbol)
710 return unchanged(expr);
711
712 const irep_idt &func_id = to_symbol_expr(expr.function()).get_identifier();
713
714 // String.startsWith() is used to implement String.equals() in the models
715 // library
716 if(func_id == ID_cprover_string_startswith_func)
717 {
718 return simplify_string_startswith(expr, ns);
719 }
720 else if(func_id == ID_cprover_string_endswith_func)
721 {
722 return simplify_string_endswith(expr, ns);
723 }
724 else if(func_id == ID_cprover_string_is_empty_func)
725 {
726 return simplify_string_is_empty(expr, ns);
727 }
728 else if(func_id == ID_cprover_string_compare_to_func)
729 {
730 return simplify_string_compare_to(expr, ns);
731 }
732 else if(func_id == ID_cprover_string_index_of_func)
733 {
734 return simplify_string_index_of(expr, ns, false);
735 }
736 else if(func_id == ID_cprover_string_char_at_func)
737 {
738 return simplify_string_char_at(expr, ns);
739 }
740 else if(func_id == ID_cprover_string_contains_func)
741 {
742 return simplify_string_contains(expr, ns);
743 }
744 else if(func_id == ID_cprover_string_last_index_of_func)
745 {
746 return simplify_string_index_of(expr, ns, true);
747 }
748 else if(func_id == ID_cprover_string_equals_ignore_case_func)
749 {
751 }
752
753 return unchanged(expr);
754}
755
758{
759 const typet &expr_type = expr.type();
760 const typet &op_type = expr.op().type();
761
762 // eliminate casts of infinity
763 if(expr.op().id() == ID_infinity)
764 {
765 typet new_type=expr.type();
766 exprt tmp = expr.op();
767 tmp.type()=new_type;
768 return std::move(tmp);
769 }
770
771 // casts from NULL to any integer
772 if(
773 op_type.id() == ID_pointer && expr.op().is_constant() &&
774 to_constant_expr(expr.op()).get_value() == ID_NULL &&
775 (expr_type.id() == ID_unsignedbv || expr_type.id() == ID_signedbv) &&
777 {
778 return from_integer(0, expr_type);
779 }
780
781 // casts from pointer to integer
782 // where width of integer >= width of pointer
783 // (void*)(intX)expr -> (void*)expr
784 if(
785 expr_type.id() == ID_pointer && expr.op().id() == ID_typecast &&
786 (op_type.id() == ID_signedbv || op_type.id() == ID_unsignedbv ||
787 op_type.id() == ID_bv) &&
788 to_bitvector_type(op_type).get_width() >=
789 to_bitvector_type(expr_type).get_width())
790 {
791 auto new_expr = expr;
792 new_expr.op() = to_typecast_expr(expr.op()).op();
793 return changed(simplify_typecast(new_expr)); // rec. call
794 }
795
796 // eliminate redundant typecasts
797 if(expr.type() == expr.op().type())
798 {
799 return expr.op();
800 }
801
802 // eliminate casts to proper bool
803 if(expr_type.id()==ID_bool)
804 {
805 // rewrite (bool)x to x!=0
806 binary_relation_exprt inequality(
807 expr.op(),
808 op_type.id() == ID_floatbv ? ID_ieee_float_notequal : ID_notequal,
809 from_integer(0, op_type));
810 inequality.add_source_location()=expr.source_location();
811 return changed(simplify_node(inequality));
812 }
813
814 // eliminate casts from proper bool
815 if(
816 op_type.id() == ID_bool &&
817 (expr_type.id() == ID_signedbv || expr_type.id() == ID_unsignedbv ||
818 expr_type.id() == ID_c_bool || expr_type.id() == ID_c_bit_field))
819 {
820 // rewrite (T)(bool) to bool?1:0
821 auto one = from_integer(1, expr_type);
822 auto zero = from_integer(0, expr_type);
824 if_exprt{expr.op(), std::move(one), std::move(zero)}));
825 }
826
827 // circular casts through types shorter than `int`
828 // we use fixed bit widths as this is specifically for the Java bytecode
829 // front-end
830 if(op_type == signedbv_typet(32) && expr.op().id() == ID_typecast)
831 {
832 if(expr_type==c_bool_typet(8) ||
833 expr_type==signedbv_typet(8) ||
834 expr_type==signedbv_typet(16) ||
835 expr_type==unsignedbv_typet(16))
836 {
837 // We checked that the id was ID_typecast in the enclosing `if`
838 const auto &typecast = expr_checked_cast<typecast_exprt>(expr.op());
839 if(typecast.op().type()==expr_type)
840 {
841 return typecast.op();
842 }
843 }
844 }
845
846 // eliminate casts to _Bool
847 if(expr_type.id()==ID_c_bool &&
848 op_type.id()!=ID_bool)
849 {
850 // rewrite (_Bool)x to (_Bool)(x!=0)
851 exprt inequality = is_not_zero(expr.op(), ns);
852 auto new_expr = expr;
853 new_expr.op() = simplify_node(std::move(inequality));
854 return changed(simplify_typecast(new_expr)); // recursive call
855 }
856
857 // eliminate typecasts from NULL
858 if(
859 expr_type.id() == ID_pointer && expr.op().is_constant() &&
860 (to_constant_expr(expr.op()).get_value() == ID_NULL ||
861 (expr.op().is_zero() && config.ansi_c.NULL_is_zero)))
862 {
863 exprt tmp = expr.op();
864 tmp.type()=expr.type();
865 to_constant_expr(tmp).set_value(ID_NULL);
866 return std::move(tmp);
867 }
868
869 // eliminate duplicate pointer typecasts
870 // (T1 *)(T2 *)x -> (T1 *)x
871 if(
872 expr_type.id() == ID_pointer && expr.op().id() == ID_typecast &&
873 op_type.id() == ID_pointer)
874 {
875 auto new_expr = expr;
876 new_expr.op() = to_typecast_expr(expr.op()).op();
877 return changed(simplify_typecast(new_expr)); // recursive call
878 }
879
880 // casts from integer to pointer and back:
881 // (int)(void *)int -> (int)(size_t)int
882 if(
883 (expr_type.id() == ID_signedbv || expr_type.id() == ID_unsignedbv) &&
884 expr.op().id() == ID_typecast && expr.op().operands().size() == 1 &&
885 op_type.id() == ID_pointer)
886 {
887 auto inner_cast = to_typecast_expr(expr.op());
888 inner_cast.type() = size_type();
889
890 auto outer_cast = expr;
891 outer_cast.op() = simplify_typecast(inner_cast); // rec. call
892 return changed(simplify_typecast(outer_cast)); // rec. call
893 }
894
895 // mildly more elaborate version of the above:
896 // (int)((T*)0 + int) -> (int)(sizeof(T)*(size_t)int) if NULL is zero
897 if(
899 (expr_type.id() == ID_signedbv || expr_type.id() == ID_unsignedbv) &&
900 op_type.id() == ID_pointer && expr.op().id() == ID_plus &&
901 expr.op().operands().size() == 2)
902 {
903 const auto &op_plus_expr = to_plus_expr(expr.op());
904
905 if(
906 (op_plus_expr.op0().id() == ID_typecast &&
907 to_typecast_expr(op_plus_expr.op0()).op().is_zero()) ||
908 (op_plus_expr.op0().is_constant() &&
909 to_constant_expr(op_plus_expr.op0()).is_null_pointer()))
910 {
911 auto sub_size =
912 pointer_offset_size(to_pointer_type(op_type).base_type(), ns);
913 if(sub_size.has_value())
914 {
915 auto new_expr = expr;
916 exprt offset_expr =
917 simplify_typecast(typecast_exprt(op_plus_expr.op1(), size_type()));
918
919 // void*
920 if(*sub_size == 0 || *sub_size == 1)
921 new_expr.op() = offset_expr;
922 else
923 {
924 new_expr.op() = simplify_mult(
925 mult_exprt(from_integer(*sub_size, size_type()), offset_expr));
926 }
927
928 return changed(simplify_typecast(new_expr)); // rec. call
929 }
930 }
931 }
932
933 // Push a numerical typecast into various integer operations, i.e.,
934 // (T)(x OP y) ---> (T)x OP (T)y
935 //
936 // Doesn't work for many, e.g., pointer difference, floating-point,
937 // division, modulo.
938 // Many operations fail if the width of T
939 // is bigger than that of (x OP y). This includes ID_bitnot and
940 // anything that might overflow, e.g., ID_plus.
941 //
942 if((expr_type.id()==ID_signedbv || expr_type.id()==ID_unsignedbv) &&
943 (op_type.id()==ID_signedbv || op_type.id()==ID_unsignedbv))
944 {
945 bool enlarge=
946 to_bitvector_type(expr_type).get_width()>
947 to_bitvector_type(op_type).get_width();
948
949 if(!enlarge)
950 {
951 irep_idt op_id = expr.op().id();
952
953 if(
954 op_id == ID_plus || op_id == ID_minus || op_id == ID_mult ||
955 op_id == ID_unary_minus || op_id == ID_bitxor || op_id == ID_bitxnor ||
956 op_id == ID_bitor || op_id == ID_bitand)
957 {
958 exprt result = expr.op();
959
960 if(
961 result.operands().size() >= 1 &&
962 to_multi_ary_expr(result).op0().type() == result.type())
963 {
964 result.type()=expr.type();
965
966 Forall_operands(it, result)
967 {
968 auto new_operand = typecast_exprt(*it, expr.type());
969 *it = simplify_typecast(new_operand); // recursive call
970 }
971
972 return changed(simplify_node(result)); // possibly recursive call
973 }
974 }
975 else if(op_id==ID_ashr || op_id==ID_lshr || op_id==ID_shl)
976 {
977 }
978 }
979 }
980
981 // Push a numerical typecast into pointer arithmetic
982 // (T)(ptr + int) ---> (T)((size_t)ptr + sizeof(subtype)*(size_t)int)
983 //
984 if(
985 (expr_type.id() == ID_signedbv || expr_type.id() == ID_unsignedbv) &&
986 op_type.id() == ID_pointer && expr.op().id() == ID_plus)
987 {
988 const auto step =
989 pointer_offset_size(to_pointer_type(op_type).base_type(), ns);
990
991 if(step.has_value() && *step != 0)
992 {
993 const typet size_t_type(size_type());
994 auto new_expr = expr;
995
996 new_expr.op().type() = size_t_type;
997
998 for(auto &op : new_expr.op().operands())
999 {
1000 exprt new_op = simplify_typecast(typecast_exprt(op, size_t_type));
1001 if(op.type().id() != ID_pointer && *step > 1)
1002 {
1003 new_op =
1004 simplify_mult(mult_exprt(from_integer(*step, size_t_type), new_op));
1005 }
1006 op = std::move(new_op);
1007 }
1008
1009 new_expr.op() = simplify_plus(to_plus_expr(new_expr.op()));
1010
1011 return changed(simplify_typecast(new_expr)); // recursive call
1012 }
1013 }
1014
1015 const irep_idt &expr_type_id=expr_type.id();
1016 const exprt &operand = expr.op();
1017 const irep_idt &op_type_id=op_type.id();
1018
1019 if(operand.is_constant())
1020 {
1021 const irep_idt &value=to_constant_expr(operand).get_value();
1022
1023 // preserve the sizeof type annotation
1024 typet c_sizeof_type=
1025 static_cast<const typet &>(operand.find(ID_C_c_sizeof_type));
1026
1027 if(op_type_id==ID_integer ||
1028 op_type_id==ID_natural)
1029 {
1030 // from integer to ...
1031
1032 mp_integer int_value=string2integer(id2string(value));
1033
1034 if(expr_type_id==ID_bool)
1035 {
1036 return make_boolean_expr(int_value != 0);
1037 }
1038
1039 if(expr_type_id==ID_unsignedbv ||
1040 expr_type_id==ID_signedbv ||
1041 expr_type_id==ID_c_enum ||
1042 expr_type_id==ID_c_bit_field ||
1043 expr_type_id==ID_integer)
1044 {
1045 return from_integer(int_value, expr_type);
1046 }
1047 else if(expr_type_id == ID_c_enum_tag)
1048 {
1049 const auto &c_enum_type = ns.follow_tag(to_c_enum_tag_type(expr_type));
1050 if(!c_enum_type.is_incomplete()) // possibly incomplete
1051 {
1052 exprt tmp = from_integer(int_value, c_enum_type);
1053 tmp.type() = expr_type; // we maintain the tag type
1054 return std::move(tmp);
1055 }
1056 }
1057 }
1058 else if(op_type_id==ID_rational)
1059 {
1060 }
1061 else if(op_type_id==ID_real)
1062 {
1063 }
1064 else if(op_type_id==ID_bool)
1065 {
1066 if(expr_type_id==ID_unsignedbv ||
1067 expr_type_id==ID_signedbv ||
1068 expr_type_id==ID_integer ||
1069 expr_type_id==ID_natural ||
1070 expr_type_id==ID_rational ||
1071 expr_type_id==ID_c_bool ||
1072 expr_type_id==ID_c_enum ||
1073 expr_type_id==ID_c_bit_field)
1074 {
1075 if(operand.is_true())
1076 {
1077 return from_integer(1, expr_type);
1078 }
1079 else if(operand.is_false())
1080 {
1081 return from_integer(0, expr_type);
1082 }
1083 }
1084 else if(expr_type_id==ID_c_enum_tag)
1085 {
1086 const auto &c_enum_type = ns.follow_tag(to_c_enum_tag_type(expr_type));
1087 if(!c_enum_type.is_incomplete()) // possibly incomplete
1088 {
1089 unsigned int_value = operand.is_true() ? 1u : 0u;
1090 exprt tmp=from_integer(int_value, c_enum_type);
1091 tmp.type()=expr_type; // we maintain the tag type
1092 return std::move(tmp);
1093 }
1094 }
1095 else if(expr_type_id==ID_pointer &&
1096 operand.is_false() &&
1098 {
1099 return null_pointer_exprt(to_pointer_type(expr_type));
1100 }
1101 }
1102 else if(op_type_id==ID_unsignedbv ||
1103 op_type_id==ID_signedbv ||
1104 op_type_id==ID_c_bit_field ||
1105 op_type_id==ID_c_bool)
1106 {
1107 mp_integer int_value;
1108
1109 if(to_integer(to_constant_expr(operand), int_value))
1110 return unchanged(expr);
1111
1112 if(expr_type_id==ID_bool)
1113 {
1114 return make_boolean_expr(int_value != 0);
1115 }
1116
1117 if(expr_type_id==ID_c_bool)
1118 {
1119 return from_integer(int_value != 0, expr_type);
1120 }
1121
1122 if(expr_type_id==ID_integer)
1123 {
1124 return from_integer(int_value, expr_type);
1125 }
1126
1127 if(expr_type_id==ID_natural)
1128 {
1129 if(int_value>=0)
1130 {
1131 return from_integer(int_value, expr_type);
1132 }
1133 }
1134
1135 if(expr_type_id==ID_unsignedbv ||
1136 expr_type_id==ID_signedbv ||
1137 expr_type_id==ID_bv ||
1138 expr_type_id==ID_c_bit_field)
1139 {
1140 auto result = from_integer(int_value, expr_type);
1141
1142 if(c_sizeof_type.is_not_nil())
1143 result.set(ID_C_c_sizeof_type, c_sizeof_type);
1144
1145 return std::move(result);
1146 }
1147
1148 if(expr_type_id==ID_c_enum_tag)
1149 {
1150 const auto &c_enum_type = ns.follow_tag(to_c_enum_tag_type(expr_type));
1151 if(!c_enum_type.is_incomplete()) // possibly incomplete
1152 {
1153 exprt tmp=from_integer(int_value, c_enum_type);
1154 tmp.type()=expr_type; // we maintain the tag type
1155 return std::move(tmp);
1156 }
1157 }
1158
1159 if(expr_type_id==ID_c_enum)
1160 {
1161 return from_integer(int_value, expr_type);
1162 }
1163
1164 if(expr_type_id==ID_fixedbv)
1165 {
1166 // int to float
1167 const fixedbv_typet &f_expr_type=
1168 to_fixedbv_type(expr_type);
1169
1170 fixedbvt f;
1171 f.spec=fixedbv_spect(f_expr_type);
1172 f.from_integer(int_value);
1173 return f.to_expr();
1174 }
1175
1176 if(expr_type_id==ID_floatbv)
1177 {
1178 // int to float
1179 const floatbv_typet &f_expr_type=
1180 to_floatbv_type(expr_type);
1181
1182 ieee_floatt f(f_expr_type);
1183 f.from_integer(int_value);
1184
1185 return f.to_expr();
1186 }
1187
1188 if(expr_type_id==ID_rational)
1189 {
1190 rationalt r(int_value);
1191 return from_rational(r);
1192 }
1193 }
1194 else if(op_type_id==ID_fixedbv)
1195 {
1196 if(expr_type_id==ID_unsignedbv ||
1197 expr_type_id==ID_signedbv)
1198 {
1199 // cast from fixedbv to int
1200 fixedbvt f(to_constant_expr(expr.op()));
1201 return from_integer(f.to_integer(), expr_type);
1202 }
1203 else if(expr_type_id==ID_fixedbv)
1204 {
1205 // fixedbv to fixedbv
1206 fixedbvt f(to_constant_expr(expr.op()));
1207 f.round(fixedbv_spect(to_fixedbv_type(expr_type)));
1208 return f.to_expr();
1209 }
1210 else if(expr_type_id == ID_bv)
1211 {
1212 fixedbvt f{to_constant_expr(expr.op())};
1213 return from_integer(f.get_value(), expr_type);
1214 }
1215 }
1216 else if(op_type_id==ID_floatbv)
1217 {
1218 ieee_floatt f(to_constant_expr(expr.op()));
1219
1220 if(expr_type_id==ID_unsignedbv ||
1221 expr_type_id==ID_signedbv)
1222 {
1223 // cast from float to int
1224 return from_integer(f.to_integer(), expr_type);
1225 }
1226 else if(expr_type_id==ID_floatbv)
1227 {
1228 // float to double or double to float
1230 return f.to_expr();
1231 }
1232 else if(expr_type_id==ID_fixedbv)
1233 {
1234 fixedbvt fixedbv;
1235 fixedbv.spec=fixedbv_spect(to_fixedbv_type(expr_type));
1236 ieee_floatt factor(f.spec);
1237 factor.from_integer(power(2, fixedbv.spec.get_fraction_bits()));
1238 f*=factor;
1239 fixedbv.set_value(f.to_integer());
1240 return fixedbv.to_expr();
1241 }
1242 else if(expr_type_id == ID_bv)
1243 {
1244 return from_integer(f.pack(), expr_type);
1245 }
1246 }
1247 else if(op_type_id==ID_bv)
1248 {
1249 if(
1250 expr_type_id == ID_unsignedbv || expr_type_id == ID_signedbv ||
1251 expr_type_id == ID_c_enum || expr_type_id == ID_c_enum_tag ||
1252 expr_type_id == ID_c_bit_field)
1253 {
1254 const auto width = to_bv_type(op_type).get_width();
1255 const auto int_value = bvrep2integer(value, width, false);
1256 if(expr_type_id != ID_c_enum_tag)
1257 return from_integer(int_value, expr_type);
1258 else
1259 {
1260 c_enum_tag_typet tag_type = to_c_enum_tag_type(expr_type);
1261 auto result = from_integer(int_value, ns.follow_tag(tag_type));
1262 result.type() = tag_type;
1263 return std::move(result);
1264 }
1265 }
1266 else if(expr_type_id == ID_floatbv)
1267 {
1268 const auto width = to_bv_type(op_type).get_width();
1269 const auto int_value = bvrep2integer(value, width, false);
1270 ieee_floatt ieee_float{to_floatbv_type(expr_type)};
1271 ieee_float.unpack(int_value);
1272 return ieee_float.to_expr();
1273 }
1274 else if(expr_type_id == ID_fixedbv)
1275 {
1276 const auto width = to_bv_type(op_type).get_width();
1277 const auto int_value = bvrep2integer(value, width, false);
1278 fixedbvt fixedbv{fixedbv_spect{to_fixedbv_type(expr_type)}};
1279 fixedbv.set_value(int_value);
1280 return fixedbv.to_expr();
1281 }
1282 }
1283 else if(op_type_id==ID_c_enum_tag) // enum to int
1284 {
1285 const typet &base_type =
1286 ns.follow_tag(to_c_enum_tag_type(op_type)).underlying_type();
1287 if(base_type.id()==ID_signedbv || base_type.id()==ID_unsignedbv)
1288 {
1289 // enum constants use the representation of their base type
1290 auto new_expr = expr;
1291 new_expr.op().type() = base_type;
1292 return changed(simplify_typecast(new_expr)); // recursive call
1293 }
1294 }
1295 else if(op_type_id==ID_c_enum) // enum to int
1296 {
1297 const typet &base_type = to_c_enum_type(op_type).underlying_type();
1298 if(base_type.id()==ID_signedbv || base_type.id()==ID_unsignedbv)
1299 {
1300 // enum constants use the representation of their base type
1301 auto new_expr = expr;
1302 new_expr.op().type() = base_type;
1303 return changed(simplify_typecast(new_expr)); // recursive call
1304 }
1305 }
1306 }
1307 else if(operand.id()==ID_typecast) // typecast of typecast
1308 {
1309 // (T1)(T2)x ---> (T1)
1310 // where T1 has fewer bits than T2
1311 if(
1312 op_type_id == expr_type_id &&
1313 (expr_type_id == ID_unsignedbv || expr_type_id == ID_signedbv ||
1314 expr_type_id == ID_bv) &&
1315 to_bitvector_type(expr_type).get_width() <=
1316 to_bitvector_type(operand.type()).get_width())
1317 {
1318 auto new_expr = expr;
1319 new_expr.op() = to_typecast_expr(operand).op();
1320 // might enable further simplification
1321 return changed(simplify_typecast(new_expr)); // recursive call
1322 }
1323 }
1324 else if(operand.id()==ID_address_of)
1325 {
1326 const exprt &o=to_address_of_expr(operand).object();
1327
1328 // turn &array into &array[0] when casting to pointer-to-element-type
1329 if(
1330 o.type().id() == ID_array &&
1331 expr_type == pointer_type(to_array_type(o.type()).element_type()))
1332 {
1333 auto result =
1335
1336 return changed(simplify_address_of(result)); // recursive call
1337 }
1338 }
1339
1340 return unchanged(expr);
1341}
1342
1345{
1346 const typet &expr_type = expr.type();
1347 const typet &op_type = expr.op().type();
1348
1349 // (T)(a?b:c) --> a?(T)b:(T)c; don't do this for floating-point type casts as
1350 // the type cast itself may be costly
1351 if(
1352 expr.op().id() == ID_if && expr_type.id() != ID_floatbv &&
1353 op_type.id() != ID_floatbv)
1354 {
1355 if_exprt if_expr = lift_if(expr, 0);
1356 return changed(simplify_if_preorder(if_expr));
1357 }
1358 else
1359 {
1360 auto r_it = simplify_rec(expr.op()); // recursive call
1361 if(r_it.has_changed())
1362 {
1363 auto tmp = expr;
1364 tmp.op() = r_it.expr;
1365 return tmp;
1366 }
1367 }
1368
1369 return unchanged(expr);
1370}
1371
1374{
1375 const exprt &pointer = expr.pointer();
1376
1377 if(pointer.type().id()!=ID_pointer)
1378 return unchanged(expr);
1379
1380 if(pointer.id()==ID_address_of)
1381 {
1382 exprt tmp=to_address_of_expr(pointer).object();
1383 // one address_of is gone, try again
1384 return changed(simplify_rec(tmp));
1385 }
1386 // rewrite *(&a[0] + x) to a[x]
1387 else if(
1388 pointer.id() == ID_plus && pointer.operands().size() == 2 &&
1389 to_plus_expr(pointer).op0().id() == ID_address_of)
1390 {
1391 const auto &pointer_plus_expr = to_plus_expr(pointer);
1392
1393 const address_of_exprt &address_of =
1394 to_address_of_expr(pointer_plus_expr.op0());
1395
1396 if(address_of.object().id()==ID_index)
1397 {
1398 const index_exprt &old=to_index_expr(address_of.object());
1399 if(old.array().type().id() == ID_array)
1400 {
1401 index_exprt idx(
1402 old.array(),
1403 pointer_offset_sum(old.index(), pointer_plus_expr.op1()),
1405 return changed(simplify_rec(idx));
1406 }
1407 }
1408 }
1409
1410 return unchanged(expr);
1411}
1412
1415{
1416 const exprt &pointer = expr.pointer();
1417
1418 if(pointer.id() == ID_if)
1419 {
1420 if_exprt if_expr = lift_if(expr, 0);
1421 return changed(simplify_if_preorder(if_expr));
1422 }
1423 else
1424 {
1425 auto r_it = simplify_rec(pointer); // recursive call
1426 if(r_it.has_changed())
1427 {
1428 auto tmp = expr;
1429 tmp.pointer() = r_it.expr;
1430 return tmp;
1431 }
1432 }
1433
1434 return unchanged(expr);
1435}
1436
1439{
1440 return unchanged(expr);
1441}
1442
1444{
1445 bool no_change = true;
1446
1447 if((expr.operands().size()%2)!=1)
1448 return unchanged(expr);
1449
1450 // copy
1451 auto with_expr = expr;
1452
1453 // now look at first operand
1454
1455 if(
1456 with_expr.old().type().id() == ID_struct ||
1457 with_expr.old().type().id() == ID_struct_tag)
1458 {
1459 if(with_expr.old().id() == ID_struct || with_expr.old().is_constant())
1460 {
1461 while(with_expr.operands().size() > 1)
1462 {
1463 const irep_idt &component_name =
1464 with_expr.where().get(ID_component_name);
1465
1466 const struct_typet &old_type_followed =
1467 with_expr.old().type().id() == ID_struct_tag
1468 ? ns.follow_tag(to_struct_tag_type(with_expr.old().type()))
1469 : to_struct_type(with_expr.old().type());
1470 if(!old_type_followed.has_component(component_name))
1471 return unchanged(expr);
1472
1473 std::size_t number = old_type_followed.component_number(component_name);
1474
1475 if(number >= with_expr.old().operands().size())
1476 return unchanged(expr);
1477
1478 with_expr.old().operands()[number].swap(with_expr.new_value());
1479
1480 with_expr.operands().erase(++with_expr.operands().begin());
1481 with_expr.operands().erase(++with_expr.operands().begin());
1482
1483 no_change = false;
1484 }
1485 }
1486 }
1487 else if(
1488 with_expr.old().type().id() == ID_array ||
1489 with_expr.old().type().id() == ID_vector)
1490 {
1491 if(
1492 with_expr.old().id() == ID_array || with_expr.old().is_constant() ||
1493 with_expr.old().id() == ID_vector)
1494 {
1495 while(with_expr.operands().size() > 1)
1496 {
1497 const auto i = numeric_cast<mp_integer>(with_expr.where());
1498
1499 if(!i.has_value())
1500 break;
1501
1502 if(*i < 0 || *i >= with_expr.old().operands().size())
1503 break;
1504
1505 with_expr.old().operands()[numeric_cast_v<std::size_t>(*i)].swap(
1506 with_expr.new_value());
1507
1508 with_expr.operands().erase(++with_expr.operands().begin());
1509 with_expr.operands().erase(++with_expr.operands().begin());
1510
1511 no_change = false;
1512 }
1513 }
1514 }
1515
1516 if(with_expr.operands().size() == 1)
1517 return with_expr.old();
1518
1519 if(no_change)
1520 return unchanged(expr);
1521 else
1522 return std::move(with_expr);
1523}
1524
1527{
1528 // this is to push updates into (possibly nested) constants
1529
1530 const exprt::operandst &designator = expr.designator();
1531
1532 exprt updated_value = expr.old();
1533 exprt *value_ptr=&updated_value;
1534
1535 for(const auto &e : designator)
1536 {
1537 if(e.id()==ID_index_designator &&
1538 value_ptr->id()==ID_array)
1539 {
1540 const auto i = numeric_cast<mp_integer>(to_index_designator(e).index());
1541
1542 if(!i.has_value())
1543 return unchanged(expr);
1544
1545 if(*i < 0 || *i >= value_ptr->operands().size())
1546 return unchanged(expr);
1547
1548 value_ptr = &value_ptr->operands()[numeric_cast_v<std::size_t>(*i)];
1549 }
1550 else if(e.id()==ID_member_designator &&
1551 value_ptr->id()==ID_struct)
1552 {
1553 const irep_idt &component_name=
1554 e.get(ID_component_name);
1555 const struct_typet &value_ptr_struct_type =
1556 value_ptr->type().id() == ID_struct_tag
1557 ? ns.follow_tag(to_struct_tag_type(value_ptr->type()))
1558 : to_struct_type(value_ptr->type());
1559 if(!value_ptr_struct_type.has_component(component_name))
1560 return unchanged(expr);
1561 auto &designator_as_struct_expr = to_struct_expr(*value_ptr);
1562 value_ptr = &designator_as_struct_expr.component(component_name, ns);
1563 CHECK_RETURN(value_ptr->is_not_nil());
1564 }
1565 else
1566 return unchanged(expr); // give up, unknown designator
1567 }
1568
1569 // found, done
1570 *value_ptr = expr.new_value();
1571 return updated_value;
1572}
1573
1575{
1576 if(expr.id()==ID_plus)
1577 {
1578 if(expr.type().id()==ID_pointer)
1579 {
1580 // kill integers from sum
1581 for(auto &op : expr.operands())
1582 if(op.type().id() == ID_pointer)
1583 return changed(simplify_object(op)); // recursive call
1584 }
1585 }
1586 else if(expr.id()==ID_typecast)
1587 {
1588 auto const &typecast_expr = to_typecast_expr(expr);
1589 const typet &op_type = typecast_expr.op().type();
1590
1591 if(op_type.id()==ID_pointer)
1592 {
1593 // cast from pointer to pointer
1594 return changed(simplify_object(typecast_expr.op())); // recursive call
1595 }
1596 else if(op_type.id()==ID_signedbv || op_type.id()==ID_unsignedbv)
1597 {
1598 // cast from integer to pointer
1599
1600 // We do a bit of special treatment for (TYPE *)(a+(int)&o) and
1601 // (TYPE *)(a+(int)((T*)&o+x)), which are re-written to '&o'.
1602
1603 const exprt &casted_expr = typecast_expr.op();
1604 if(casted_expr.id() == ID_plus && casted_expr.operands().size() == 2)
1605 {
1606 const auto &plus_expr = to_plus_expr(casted_expr);
1607
1608 const exprt &cand = plus_expr.op0().id() == ID_typecast
1609 ? plus_expr.op0()
1610 : plus_expr.op1();
1611
1612 if(cand.id() == ID_typecast)
1613 {
1614 const auto &typecast_op = to_typecast_expr(cand).op();
1615
1616 if(typecast_op.id() == ID_address_of)
1617 {
1618 return typecast_op;
1619 }
1620 else if(
1621 typecast_op.id() == ID_plus && typecast_op.operands().size() == 2 &&
1622 to_plus_expr(typecast_op).op0().id() == ID_typecast &&
1623 to_typecast_expr(to_plus_expr(typecast_op).op0()).op().id() ==
1624 ID_address_of)
1625 {
1626 return to_typecast_expr(to_plus_expr(typecast_op).op0()).op();
1627 }
1628 }
1629 }
1630 }
1631 }
1632 else if(expr.id()==ID_address_of)
1633 {
1634 const auto &object = to_address_of_expr(expr).object();
1635
1636 if(object.id() == ID_index)
1637 {
1638 // &some[i] -> &some
1639 address_of_exprt new_expr(to_index_expr(object).array());
1640 return changed(simplify_object(new_expr)); // recursion
1641 }
1642 else if(object.id() == ID_member)
1643 {
1644 // &some.f -> &some
1645 address_of_exprt new_expr(to_member_expr(object).compound());
1646 return changed(simplify_object(new_expr)); // recursion
1647 }
1648 }
1649
1650 return unchanged(expr);
1651}
1652
1655{
1656 // lift up any ID_if on the object
1657 if(expr.op().id() == ID_if)
1658 {
1659 if_exprt if_expr = lift_if(expr, 0);
1660 if_expr.true_case() =
1662 if_expr.false_case() =
1664 return changed(simplify_if(if_expr));
1665 }
1666
1667 const auto el_size = pointer_offset_bits(expr.type(), ns);
1668 if(el_size.has_value() && *el_size < 0)
1669 return unchanged(expr);
1670
1671 // byte_extract(byte_extract(root, offset1), offset2) =>
1672 // byte_extract(root, offset1+offset2)
1673 if(expr.op().id()==expr.id())
1674 {
1675 auto tmp = expr;
1676
1679 to_byte_extract_expr(expr.op()).offset(), expr.offset().type()),
1680 expr.offset()));
1681 tmp.op() = to_byte_extract_expr(expr.op()).op();
1682
1683 return changed(simplify_byte_extract(tmp)); // recursive call
1684 }
1685
1686 // byte_extract(byte_update(root, offset, value), offset) =>
1687 // value
1688 if(
1689 ((expr.id() == ID_byte_extract_big_endian &&
1690 expr.op().id() == ID_byte_update_big_endian) ||
1691 (expr.id() == ID_byte_extract_little_endian &&
1692 expr.op().id() == ID_byte_update_little_endian)) &&
1693 expr.offset() == to_byte_update_expr(as_const(expr).op()).offset())
1694 {
1695 const auto &op_byte_update = to_byte_update_expr(expr.op());
1696
1697 if(expr.type() == op_byte_update.value().type())
1698 {
1699 return op_byte_update.value();
1700 }
1701 else if(el_size.has_value())
1702 {
1703 const auto update_bits_opt =
1704 pointer_offset_bits(op_byte_update.value().type(), ns);
1705
1706 if(update_bits_opt.has_value() && *el_size <= *update_bits_opt)
1707 {
1708 auto tmp = expr;
1709 tmp.op() = op_byte_update.value();
1710 tmp.offset() = from_integer(0, expr.offset().type());
1711
1712 return changed(simplify_byte_extract(tmp)); // recursive call
1713 }
1714 }
1715 }
1716
1717 // the following require a constant offset
1718 auto offset = numeric_cast<mp_integer>(expr.offset());
1719 if(!offset.has_value() || *offset < 0)
1720 return unchanged(expr);
1721
1722 // try to simplify byte_extract(byte_update(...))
1723 auto const bu = expr_try_dynamic_cast<byte_update_exprt>(expr.op());
1724 std::optional<mp_integer> update_offset;
1725 if(bu)
1726 update_offset = numeric_cast<mp_integer>(bu->offset());
1727 if(bu && el_size.has_value() && update_offset.has_value())
1728 {
1729 // byte_extract(byte_update(root, offset_u, value), offset_e) so that the
1730 // update does not affect what is being extracted simplifies to
1731 // byte_extract(root, offset_e)
1732 //
1733 // byte_extract(byte_update(root, offset_u, value), offset_e) so that the
1734 // extracted range fully lies within the update value simplifies to
1735 // byte_extract(value, offset_e - offset_u)
1736 if(
1737 *offset * expr.get_bits_per_byte() + *el_size <=
1738 *update_offset * bu->get_bits_per_byte())
1739 {
1740 // extracting before the update
1741 auto tmp = expr;
1742 tmp.op() = bu->op();
1743 return changed(simplify_byte_extract(tmp)); // recursive call
1744 }
1745 else if(
1746 const auto update_size = pointer_offset_bits(bu->value().type(), ns))
1747 {
1748 if(
1749 *offset * expr.get_bits_per_byte() >=
1750 *update_offset * bu->get_bits_per_byte() + *update_size)
1751 {
1752 // extracting after the update
1753 auto tmp = expr;
1754 tmp.op() = bu->op();
1755 return changed(simplify_byte_extract(tmp)); // recursive call
1756 }
1757 else if(
1758 *offset >= *update_offset &&
1759 *offset * expr.get_bits_per_byte() + *el_size <=
1760 *update_offset * bu->get_bits_per_byte() + *update_size)
1761 {
1762 // extracting from the update
1763 auto tmp = expr;
1764 tmp.op() = bu->value();
1765 tmp.offset() =
1766 from_integer(*offset - *update_offset, expr.offset().type());
1767 return changed(simplify_byte_extract(tmp)); // recursive call
1768 }
1769 }
1770 }
1771
1772 // don't do any of the following if endianness doesn't match, as
1773 // bytes need to be swapped
1774 if(
1775 *offset == 0 && ((expr.id() == ID_byte_extract_little_endian &&
1778 (expr.id() == ID_byte_extract_big_endian &&
1781 {
1782 // byte extract of full object is object
1783 if(expr.type() == expr.op().type())
1784 {
1785 return expr.op();
1786 }
1787 else if(
1788 expr.type().id() == ID_pointer && expr.op().type().id() == ID_pointer)
1789 {
1790 return typecast_exprt(expr.op(), expr.type());
1791 }
1792 }
1793
1794 if(
1795 (expr.type().id() == ID_union &&
1796 to_union_type(expr.type()).components().empty()) ||
1797 (expr.type().id() == ID_union_tag &&
1798 ns.follow_tag(to_union_tag_type(expr.type())).components().empty()))
1799 {
1800 return empty_union_exprt{expr.type()};
1801 }
1802 else if(
1803 (expr.type().id() == ID_struct &&
1804 to_struct_type(expr.type()).components().empty()) ||
1805 (expr.type().id() == ID_struct_tag &&
1806 ns.follow_tag(to_struct_tag_type(expr.type())).components().empty()))
1807 {
1808 return struct_exprt{{}, expr.type()};
1809 }
1810
1811 // no proper simplification for expr.type()==void
1812 // or types of unknown size
1813 if(!el_size.has_value() || *el_size == 0)
1814 return unchanged(expr);
1815
1816 if(
1817 expr.op().id() == ID_array_of &&
1818 to_array_of_expr(expr.op()).op().is_constant())
1819 {
1820 const auto const_bits_opt = expr2bits(
1821 to_array_of_expr(expr.op()).op(),
1824 ns);
1825
1826 if(!const_bits_opt.has_value())
1827 return unchanged(expr);
1828
1829 std::string const_bits=const_bits_opt.value();
1830
1831 DATA_INVARIANT(!const_bits.empty(), "bit representation must be non-empty");
1832
1833 // double the string until we have sufficiently many bits
1834 while(mp_integer(const_bits.size()) <
1835 *offset * expr.get_bits_per_byte() + *el_size)
1836 {
1837 const_bits+=const_bits;
1838 }
1839
1840 std::string el_bits = std::string(
1841 const_bits,
1843 numeric_cast_v<std::size_t>(*el_size));
1844
1845 auto tmp = bits2expr(
1846 el_bits, expr.type(), expr.id() == ID_byte_extract_little_endian, ns);
1847
1848 if(tmp.has_value())
1849 return std::move(*tmp);
1850 }
1851
1852 // in some cases we even handle non-const array_of
1853 if(
1854 expr.op().id() == ID_array_of &&
1855 (*offset * expr.get_bits_per_byte()) % (*el_size) == 0 &&
1856 *el_size <=
1858 {
1859 auto tmp = expr;
1860 tmp.op() = simplify_index(index_exprt(expr.op(), expr.offset()));
1861 tmp.offset() = from_integer(0, expr.offset().type());
1862 return changed(simplify_byte_extract(tmp));
1863 }
1864
1865 // extract bits of a constant
1866 const auto bits =
1867 expr2bits(expr.op(), expr.id() == ID_byte_extract_little_endian, ns);
1868
1869 if(
1870 bits.has_value() &&
1871 mp_integer(bits->size()) >= *el_size + *offset * expr.get_bits_per_byte())
1872 {
1873 // make sure we don't lose bits with structs containing flexible array
1874 // members
1875 const bool struct_has_flexible_array_member = has_subtype(
1876 expr.type(),
1877 [&](const typet &type) {
1878 if(type.id() != ID_struct && type.id() != ID_struct_tag)
1879 return false;
1880
1881 const struct_typet &st = type.id() == ID_struct_tag
1882 ? ns.follow_tag(to_struct_tag_type(type))
1883 : to_struct_type(type);
1884 const auto &comps = st.components();
1885 if(comps.empty() || comps.back().type().id() != ID_array)
1886 return false;
1887
1888 if(comps.back().type().get_bool(ID_C_flexible_array_member))
1889 return true;
1890
1891 const auto size =
1892 numeric_cast<mp_integer>(to_array_type(comps.back().type()).size());
1893 return !size.has_value() || *size <= 1;
1894 },
1895 ns);
1896 if(!struct_has_flexible_array_member)
1897 {
1898 std::string bits_cut = std::string(
1899 bits.value(),
1901 numeric_cast_v<std::size_t>(*el_size));
1902
1903 auto tmp = bits2expr(
1904 bits_cut, expr.type(), expr.id() == ID_byte_extract_little_endian, ns);
1905
1906 if(tmp.has_value())
1907 return std::move(*tmp);
1908 }
1909 }
1910
1911 // push byte extracts into struct or union expressions, just like
1912 // lower_byte_extract does (this is the same code, except recursive calls use
1913 // simplify rather than lower_byte_extract)
1914 if(expr.op().id() == ID_struct || expr.op().id() == ID_union)
1915 {
1916 if(expr.type().id() == ID_struct || expr.type().id() == ID_struct_tag)
1917 {
1918 const struct_typet &struct_type =
1919 expr.type().id() == ID_struct_tag
1921 : to_struct_type(expr.type());
1922 const struct_typet::componentst &components = struct_type.components();
1923
1924 bool failed = false;
1925 struct_exprt s({}, expr.type());
1926
1927 for(const auto &comp : components)
1928 {
1929 auto component_bits = pointer_offset_bits(comp.type(), ns);
1930
1931 // the next member would be misaligned, abort
1932 if(
1933 !component_bits.has_value() || *component_bits == 0 ||
1934 *component_bits % expr.get_bits_per_byte() != 0)
1935 {
1936 failed = true;
1937 break;
1938 }
1939
1940 auto member_offset_opt =
1941 member_offset_expr(struct_type, comp.get_name(), ns);
1942
1943 if(!member_offset_opt.has_value())
1944 {
1945 failed = true;
1946 break;
1947 }
1948
1949 exprt new_offset = simplify_rec(
1950 plus_exprt{expr.offset(),
1952 member_offset_opt.value(), expr.offset().type())});
1953
1954 byte_extract_exprt tmp = expr;
1955 tmp.type() = comp.type();
1956 tmp.offset() = new_offset;
1957
1959 }
1960
1961 if(!failed)
1962 return s;
1963 }
1964 else if(expr.type().id() == ID_union || expr.type().id() == ID_union_tag)
1965 {
1966 const union_typet &union_type =
1967 expr.type().id() == ID_union_tag
1969 : to_union_type(expr.type());
1970 auto widest_member_opt = union_type.find_widest_union_component(ns);
1971 if(widest_member_opt.has_value())
1972 {
1973 byte_extract_exprt be = expr;
1974 be.type() = widest_member_opt->first.type();
1975 return union_exprt{widest_member_opt->first.get_name(),
1977 expr.type()};
1978 }
1979 }
1980 }
1981 else if(expr.op().id() == ID_array)
1982 {
1983 const array_typet &array_type = to_array_type(expr.op().type());
1984 const auto &element_bit_width =
1985 pointer_offset_bits(array_type.element_type(), ns);
1986 if(element_bit_width.has_value() && *element_bit_width > 0)
1987 {
1988 if(
1989 *offset > 0 &&
1990 *offset * expr.get_bits_per_byte() % *element_bit_width == 0)
1991 {
1992 const auto elements_to_erase = numeric_cast_v<std::size_t>(
1993 (*offset * expr.get_bits_per_byte()) / *element_bit_width);
1995 slice.operands().erase(
1996 slice.operands().begin(),
1997 slice.operands().begin() +
1998 std::min(elements_to_erase, slice.operands().size()));
1999 slice.type().size() =
2000 from_integer(slice.operands().size(), slice.type().size().type());
2001 byte_extract_exprt be = expr;
2002 be.op() = slice;
2003 be.offset() = from_integer(0, expr.offset().type());
2004 return changed(simplify_byte_extract(be));
2005 }
2006 else if(*offset == 0 && *el_size % *element_bit_width == 0)
2007 {
2008 const auto elements_to_keep =
2009 numeric_cast_v<std::size_t>(*el_size / *element_bit_width);
2011 if(slice.operands().size() > elements_to_keep)
2012 {
2013 slice.operands().resize(elements_to_keep);
2014 slice.type().size() =
2015 from_integer(slice.operands().size(), slice.type().size().type());
2016 byte_extract_exprt be = expr;
2017 be.op() = slice;
2018 return changed(simplify_byte_extract(be));
2019 }
2020 }
2021 }
2022 }
2023
2024 // try to refine it down to extracting from a member or an index in an array
2025 auto subexpr =
2026 get_subexpression_at_offset(expr.op(), *offset, expr.type(), ns);
2027 if(subexpr.has_value() && subexpr.value() != expr)
2028 return changed(simplify_rec(subexpr.value())); // recursive call
2029
2030 if(can_forward_propagatet(ns)(expr))
2031 return changed(simplify_rec(lower_byte_extract(expr, ns)));
2032
2033 return unchanged(expr);
2034}
2035
2038{
2039 // lift up any ID_if on the object
2040 if(expr.op().id() == ID_if)
2041 {
2042 if_exprt if_expr = lift_if(expr, 0);
2043 return changed(simplify_if_preorder(if_expr));
2044 }
2045 else
2046 {
2047 std::optional<exprt::operandst> new_operands;
2048
2049 for(std::size_t i = 0; i < expr.operands().size(); ++i)
2050 {
2051 auto r_it = simplify_rec(expr.operands()[i]); // recursive call
2052 if(r_it.has_changed())
2053 {
2054 if(!new_operands.has_value())
2055 new_operands = expr.operands();
2056 (*new_operands)[i] = std::move(r_it.expr);
2057 }
2058 }
2059
2060 if(new_operands.has_value())
2061 {
2062 exprt result = expr;
2063 std::swap(result.operands(), *new_operands);
2064 return result;
2065 }
2066 }
2067
2068 return unchanged(expr);
2069}
2070
2073{
2074 // byte_update(byte_update(root, offset, value), offset, value2) =>
2075 // byte_update(root, offset, value2)
2076 if(
2077 expr.id() == expr.op().id() &&
2078 expr.offset() == to_byte_update_expr(expr.op()).offset() &&
2079 expr.value().type() == to_byte_update_expr(expr.op()).value().type())
2080 {
2081 auto tmp = expr;
2082 tmp.set_op(to_byte_update_expr(expr.op()).op());
2083 return std::move(tmp);
2084 }
2085
2086 const exprt &root = expr.op();
2087 const exprt &offset = expr.offset();
2088 const exprt &value = expr.value();
2089 const auto val_size = pointer_offset_bits(value.type(), ns);
2090 const auto root_size = pointer_offset_bits(root.type(), ns);
2091
2092 const auto matching_byte_extract_id =
2093 expr.id() == ID_byte_update_little_endian ? ID_byte_extract_little_endian
2094 : ID_byte_extract_big_endian;
2095
2096 // byte update of full object is byte_extract(new value)
2097 if(
2098 offset.is_zero() && val_size.has_value() && *val_size > 0 &&
2099 root_size.has_value() && *root_size > 0 && *val_size >= *root_size)
2100 {
2102 matching_byte_extract_id,
2103 value,
2104 offset,
2105 expr.get_bits_per_byte(),
2106 expr.type());
2107
2108 return changed(simplify_byte_extract(be));
2109 }
2110
2111 // update bits in a constant
2112 const auto offset_int = numeric_cast<mp_integer>(offset);
2113 if(
2114 root_size.has_value() && *root_size >= 0 && val_size.has_value() &&
2115 *val_size >= 0 && offset_int.has_value() && *offset_int >= 0 &&
2116 *offset_int * expr.get_bits_per_byte() + *val_size <= *root_size)
2117 {
2118 auto root_bits =
2119 expr2bits(root, expr.id() == ID_byte_update_little_endian, ns);
2120
2121 if(root_bits.has_value())
2122 {
2123 const auto val_bits =
2124 expr2bits(value, expr.id() == ID_byte_update_little_endian, ns);
2125
2126 if(val_bits.has_value())
2127 {
2128 root_bits->replace(
2129 numeric_cast_v<std::size_t>(*offset_int * expr.get_bits_per_byte()),
2130 numeric_cast_v<std::size_t>(*val_size),
2131 *val_bits);
2132
2133 auto tmp = bits2expr(
2134 *root_bits,
2135 expr.type(),
2136 expr.id() == ID_byte_update_little_endian,
2137 ns);
2138
2139 if(tmp.has_value())
2140 return std::move(*tmp);
2141 }
2142 }
2143 }
2144
2145 /*
2146 * byte_update(root, offset,
2147 * extract(root, offset) WITH component:=value)
2148 * =>
2149 * byte_update(root, offset + component offset,
2150 * value)
2151 */
2152
2153 if(value.id()==ID_with)
2154 {
2155 const with_exprt &with=to_with_expr(value);
2156
2157 if(with.old().id() == matching_byte_extract_id)
2158 {
2159 const byte_extract_exprt &extract=to_byte_extract_expr(with.old());
2160
2161 /* the simplification can be used only if
2162 root and offset of update and extract
2163 are the same */
2164 if(!(root==extract.op()))
2165 return unchanged(expr);
2166 if(!(offset==extract.offset()))
2167 return unchanged(expr);
2168
2169 if(with.type().id() == ID_struct || with.type().id() == ID_struct_tag)
2170 {
2171 const struct_typet &struct_type =
2172 with.type().id() == ID_struct_tag
2174 : to_struct_type(with.type());
2175 const irep_idt &component_name=with.where().get(ID_component_name);
2176 const typet &c_type = struct_type.get_component(component_name).type();
2177
2178 // is this a bit field?
2179 if(c_type.id() == ID_c_bit_field || c_type.id() == ID_bool)
2180 {
2181 // don't touch -- might not be byte-aligned
2182 }
2183 else
2184 {
2185 // new offset = offset + component offset
2186 auto i = member_offset(struct_type, component_name, ns);
2187 if(i.has_value())
2188 {
2189 exprt compo_offset = from_integer(*i, offset.type());
2190 plus_exprt new_offset(offset, compo_offset);
2191 exprt new_value(with.new_value());
2192 auto tmp = expr;
2193 tmp.set_offset(simplify_node(std::move(new_offset)));
2194 tmp.set_value(std::move(new_value));
2195 return changed(simplify_byte_update(tmp)); // recursive call
2196 }
2197 }
2198 }
2199 else if(with.type().id() == ID_array)
2200 {
2201 auto i =
2203 if(i.has_value())
2204 {
2205 const exprt &index=with.where();
2206 exprt index_offset =
2207 simplify_mult(mult_exprt(index, from_integer(*i, index.type())));
2208
2209 // index_offset may need a typecast
2210 if(offset.type() != index.type())
2211 {
2212 index_offset =
2213 simplify_typecast(typecast_exprt(index_offset, offset.type()));
2214 }
2215
2216 plus_exprt new_offset(offset, index_offset);
2217 exprt new_value(with.new_value());
2218 auto tmp = expr;
2219 tmp.set_offset(simplify_plus(std::move(new_offset)));
2220 tmp.set_value(std::move(new_value));
2221 return changed(simplify_byte_update(tmp)); // recursive call
2222 }
2223 }
2224 }
2225 }
2226
2227 // the following require a constant offset
2228 if(!offset_int.has_value() || *offset_int < 0)
2229 return unchanged(expr);
2230
2231 // size must be known
2232 if(!val_size.has_value() || *val_size == 0)
2233 return unchanged(expr);
2234
2235 // Are we updating (parts of) a struct? Do individual member updates
2236 // instead, unless there are non-byte-sized bit fields
2237 if(root.type().id() == ID_struct || root.type().id() == ID_struct_tag)
2238 {
2239 exprt result_expr;
2240 result_expr.make_nil();
2241
2242 auto update_size = pointer_offset_size(value.type(), ns);
2243
2244 const struct_typet &struct_type =
2245 root.type().id() == ID_struct_tag
2247 : to_struct_type(root.type());
2248 const struct_typet::componentst &components=
2249 struct_type.components();
2250
2251 for(const auto &component : components)
2252 {
2253 auto m_offset = member_offset(struct_type, component.get_name(), ns);
2254
2255 auto m_size_bits = pointer_offset_bits(component.type(), ns);
2256
2257 // can we determine the current offset?
2258 if(!m_offset.has_value())
2259 {
2260 result_expr.make_nil();
2261 break;
2262 }
2263
2264 // is it a byte-sized member?
2265 if(
2266 !m_size_bits.has_value() || *m_size_bits == 0 ||
2267 (*m_size_bits) % expr.get_bits_per_byte() != 0)
2268 {
2269 result_expr.make_nil();
2270 break;
2271 }
2272
2273 mp_integer m_size_bytes = (*m_size_bits) / expr.get_bits_per_byte();
2274
2275 // is that member part of the update?
2276 if(*m_offset + m_size_bytes <= *offset_int)
2277 continue;
2278 // are we done updating?
2279 else if(
2280 update_size.has_value() && *update_size > 0 &&
2281 *m_offset >= *offset_int + *update_size)
2282 {
2283 break;
2284 }
2285
2286 if(result_expr.is_nil())
2287 result_expr = as_const(expr).op();
2288
2289 exprt member_name(ID_member_name);
2290 member_name.set(ID_component_name, component.get_name());
2291 result_expr=with_exprt(result_expr, member_name, nil_exprt());
2292
2293 // are we updating on member boundaries?
2294 if(
2295 *m_offset < *offset_int ||
2296 (*m_offset == *offset_int && update_size.has_value() &&
2297 *update_size > 0 && m_size_bytes > *update_size))
2298 {
2300 expr.id(),
2301 member_exprt(root, component.get_name(), component.type()),
2302 from_integer(*offset_int - *m_offset, offset.type()),
2303 value,
2304 expr.get_bits_per_byte());
2305
2306 to_with_expr(result_expr).new_value().swap(v);
2307 }
2308 else if(
2309 update_size.has_value() && *update_size > 0 &&
2310 *m_offset + m_size_bytes > *offset_int + *update_size)
2311 {
2312 // we don't handle this for the moment
2313 result_expr.make_nil();
2314 break;
2315 }
2316 else
2317 {
2319 matching_byte_extract_id,
2320 value,
2321 from_integer(*m_offset - *offset_int, offset.type()),
2322 expr.get_bits_per_byte(),
2323 component.type());
2324
2325 to_with_expr(result_expr).new_value().swap(v);
2326 }
2327 }
2328
2329 if(result_expr.is_not_nil())
2330 return changed(simplify_rec(result_expr));
2331 }
2332
2333 // replace elements of array or struct expressions, possibly using
2334 // byte_extract
2335 if(root.id()==ID_array)
2336 {
2337 auto el_size =
2339
2340 if(
2341 !el_size.has_value() || *el_size == 0 ||
2342 (*el_size) % expr.get_bits_per_byte() != 0 ||
2343 (*val_size) % expr.get_bits_per_byte() != 0)
2344 {
2345 return unchanged(expr);
2346 }
2347
2348 exprt result=root;
2349
2350 mp_integer m_offset_bits=0, val_offset=0;
2351 Forall_operands(it, result)
2352 {
2353 if(*offset_int * expr.get_bits_per_byte() + (*val_size) <= m_offset_bits)
2354 break;
2355
2356 if(*offset_int * expr.get_bits_per_byte() < m_offset_bits + *el_size)
2357 {
2358 mp_integer bytes_req =
2359 (m_offset_bits + *el_size) / expr.get_bits_per_byte() - *offset_int;
2360 bytes_req-=val_offset;
2361 if(val_offset + bytes_req > (*val_size) / expr.get_bits_per_byte())
2362 bytes_req = (*val_size) / expr.get_bits_per_byte() - val_offset;
2363
2364 byte_extract_exprt new_val(
2365 matching_byte_extract_id,
2366 value,
2367 from_integer(val_offset, offset.type()),
2368 expr.get_bits_per_byte(),
2371 from_integer(bytes_req, offset.type())));
2372
2373 *it = byte_update_exprt(
2374 expr.id(),
2375 *it,
2377 *offset_int + val_offset - m_offset_bits / expr.get_bits_per_byte(),
2378 offset.type()),
2379 new_val,
2380 expr.get_bits_per_byte());
2381
2382 *it = simplify_rec(*it); // recursive call
2383
2384 val_offset+=bytes_req;
2385 }
2386
2387 m_offset_bits += *el_size;
2388 }
2389
2390 return std::move(result);
2391 }
2392
2393 return unchanged(expr);
2394}
2395
2398{
2399 if(expr.id() == ID_complex_real)
2400 {
2401 auto &complex_real_expr = to_complex_real_expr(expr);
2402
2403 if(complex_real_expr.op().id() == ID_complex)
2404 return to_complex_expr(complex_real_expr.op()).real();
2405 }
2406 else if(expr.id() == ID_complex_imag)
2407 {
2408 auto &complex_imag_expr = to_complex_imag_expr(expr);
2409
2410 if(complex_imag_expr.op().id() == ID_complex)
2411 return to_complex_expr(complex_imag_expr.op()).imag();
2412 }
2413
2414 return unchanged(expr);
2415}
2416
2419{
2420 // When one operand is zero, an overflow can only occur for a subtraction from
2421 // zero.
2422 if(
2423 expr.op1().is_zero() ||
2424 (expr.op0().is_zero() && !can_cast_expr<minus_overflow_exprt>(expr)))
2425 {
2426 return false_exprt{};
2427 }
2428
2429 // One is neutral element for multiplication
2430 if(
2432 (expr.op0().is_one() || expr.op1().is_one()))
2433 {
2434 return false_exprt{};
2435 }
2436
2437 // we only handle the case of same operand types
2438 if(expr.op0().type() != expr.op1().type())
2439 return unchanged(expr);
2440
2441 // catch some cases over mathematical types
2442 const irep_idt &op_type_id = expr.op0().type().id();
2443 if(
2444 op_type_id == ID_integer || op_type_id == ID_rational ||
2445 op_type_id == ID_real)
2446 {
2447 return false_exprt{};
2448 }
2449
2450 if(op_type_id == ID_natural && !can_cast_expr<minus_overflow_exprt>(expr))
2451 return false_exprt{};
2452
2453 // we only handle constants over signedbv/unsignedbv for the remaining cases
2454 if(op_type_id != ID_signedbv && op_type_id != ID_unsignedbv)
2455 return unchanged(expr);
2456
2457 if(!expr.op0().is_constant() || !expr.op1().is_constant())
2458 return unchanged(expr);
2459
2460 const auto op0_value = numeric_cast<mp_integer>(expr.op0());
2461 const auto op1_value = numeric_cast<mp_integer>(expr.op1());
2462 if(!op0_value.has_value() || !op1_value.has_value())
2463 return unchanged(expr);
2464
2465 mp_integer no_overflow_result;
2467 no_overflow_result = *op0_value + *op1_value;
2469 no_overflow_result = *op0_value - *op1_value;
2471 no_overflow_result = *op0_value * *op1_value;
2473 no_overflow_result = *op0_value << *op1_value;
2474 else
2476
2477 const std::size_t width = to_bitvector_type(expr.op0().type()).get_width();
2478 const integer_bitvector_typet bv_type{op_type_id, width};
2479 if(
2480 no_overflow_result < bv_type.smallest() ||
2481 no_overflow_result > bv_type.largest())
2482 {
2483 return true_exprt{};
2484 }
2485 else
2486 return false_exprt{};
2487}
2488
2491{
2492 // zero is a neutral element for all operations supported here
2493 if(expr.op().is_zero())
2494 return false_exprt{};
2495
2496 // catch some cases over mathematical types
2497 const irep_idt &op_type_id = expr.op().type().id();
2498 if(
2499 op_type_id == ID_integer || op_type_id == ID_rational ||
2500 op_type_id == ID_real)
2501 {
2502 return false_exprt{};
2503 }
2504
2505 if(op_type_id == ID_natural)
2506 return true_exprt{};
2507
2508 // we only handle constants over signedbv/unsignedbv for the remaining cases
2509 if(op_type_id != ID_signedbv && op_type_id != ID_unsignedbv)
2510 return unchanged(expr);
2511
2512 if(!expr.op().is_constant())
2513 return unchanged(expr);
2514
2515 const auto op_value = numeric_cast<mp_integer>(expr.op());
2516 if(!op_value.has_value())
2517 return unchanged(expr);
2518
2519 mp_integer no_overflow_result;
2521 no_overflow_result = -*op_value;
2522 else
2524
2525 const std::size_t width = to_bitvector_type(expr.op().type()).get_width();
2526 const integer_bitvector_typet bv_type{op_type_id, width};
2527 if(
2528 no_overflow_result < bv_type.smallest() ||
2529 no_overflow_result > bv_type.largest())
2530 {
2531 return true_exprt{};
2532 }
2533 else
2534 return false_exprt{};
2535}
2536
2539{
2540 if(expr.id() == ID_overflow_result_unary_minus)
2541 {
2542 // zero is a neutral element
2543 if(expr.op0().is_zero())
2544 return struct_exprt{{expr.op0(), false_exprt{}}, expr.type()};
2545
2546 // catch some cases over mathematical types
2547 const irep_idt &op_type_id = expr.op0().type().id();
2548 if(
2549 op_type_id == ID_integer || op_type_id == ID_rational ||
2550 op_type_id == ID_real)
2551 {
2552 return struct_exprt{{expr.op0(), false_exprt{}}, expr.type()};
2553 }
2554
2555 // always an overflow for natural numbers, but the result is not
2556 // representable
2557 if(op_type_id == ID_natural)
2558 return unchanged(expr);
2559
2560 // we only handle constants over signedbv/unsignedbv for the remaining cases
2561 if(op_type_id != ID_signedbv && op_type_id != ID_unsignedbv)
2562 return unchanged(expr);
2563
2564 if(!expr.op0().is_constant())
2565 return unchanged(expr);
2566
2567 const auto op_value = numeric_cast<mp_integer>(expr.op0());
2568 if(!op_value.has_value())
2569 return unchanged(expr);
2570
2571 mp_integer no_overflow_result = -*op_value;
2572
2573 const std::size_t width = to_bitvector_type(expr.op0().type()).get_width();
2574 const integer_bitvector_typet bv_type{op_type_id, width};
2575 if(
2576 no_overflow_result < bv_type.smallest() ||
2577 no_overflow_result > bv_type.largest())
2578 {
2579 return struct_exprt{
2580 {from_integer(no_overflow_result, expr.op0().type()), true_exprt{}},
2581 expr.type()};
2582 }
2583 else
2584 {
2585 return struct_exprt{
2586 {from_integer(no_overflow_result, expr.op0().type()), false_exprt{}},
2587 expr.type()};
2588 }
2589 }
2590 else
2591 {
2592 // When one operand is zero, an overflow can only occur for a subtraction
2593 // from zero.
2594 if(expr.op0().is_zero())
2595 {
2596 if(
2597 expr.id() == ID_overflow_result_plus ||
2598 expr.id() == ID_overflow_result_shl)
2599 {
2600 return struct_exprt{{expr.op1(), false_exprt{}}, expr.type()};
2601 }
2602 else if(expr.id() == ID_overflow_result_mult)
2603 {
2604 return struct_exprt{
2605 {from_integer(0, expr.op0().type()), false_exprt{}}, expr.type()};
2606 }
2607 }
2608 else if(expr.op1().is_zero())
2609 {
2610 if(
2611 expr.id() == ID_overflow_result_plus ||
2612 expr.id() == ID_overflow_result_minus ||
2613 expr.id() == ID_overflow_result_shl)
2614 {
2615 return struct_exprt{{expr.op0(), false_exprt{}}, expr.type()};
2616 }
2617 else
2618 {
2619 return struct_exprt{
2620 {from_integer(0, expr.op0().type()), false_exprt{}}, expr.type()};
2621 }
2622 }
2623
2624 // One is neutral element for multiplication
2625 if(
2626 expr.id() == ID_overflow_result_mult &&
2627 (expr.op0().is_one() || expr.op1().is_one()))
2628 {
2629 return struct_exprt{
2630 {expr.op0().is_one() ? expr.op1() : expr.op0(), false_exprt{}},
2631 expr.type()};
2632 }
2633
2634 // we only handle the case of same operand types
2635 if(
2636 expr.id() != ID_overflow_result_shl &&
2637 expr.op0().type() != expr.op1().type())
2638 {
2639 return unchanged(expr);
2640 }
2641
2642 // catch some cases over mathematical types
2643 const irep_idt &op_type_id = expr.op0().type().id();
2644 if(
2645 expr.id() != ID_overflow_result_shl &&
2646 (op_type_id == ID_integer || op_type_id == ID_rational ||
2647 op_type_id == ID_real))
2648 {
2649 irep_idt id =
2650 expr.id() == ID_overflow_result_plus
2651 ? ID_plus
2652 : expr.id() == ID_overflow_result_minus ? ID_minus : ID_mult;
2653 return struct_exprt{
2654 {simplify_node(binary_exprt{expr.op0(), id, expr.op1()}),
2655 false_exprt{}},
2656 expr.type()};
2657 }
2658
2659 if(
2660 (expr.id() == ID_overflow_result_plus ||
2661 expr.id() == ID_overflow_result_mult) &&
2662 op_type_id == ID_natural)
2663 {
2664 return struct_exprt{
2666 expr.op0(),
2667 expr.id() == ID_overflow_result_plus ? ID_plus : ID_mult,
2668 expr.op1()}),
2669 false_exprt{}},
2670 expr.type()};
2671 }
2672
2673 // we only handle constants over signedbv/unsignedbv for the remaining cases
2674 if(op_type_id != ID_signedbv && op_type_id != ID_unsignedbv)
2675 return unchanged(expr);
2676
2677 // a special case of overflow-minus checking with operands (X + n) and X
2678 if(expr.id() == ID_overflow_result_minus)
2679 {
2680 const exprt &tc_op0 = skip_typecast(expr.op0());
2681 const exprt &tc_op1 = skip_typecast(expr.op1());
2682
2683 if(auto sum = expr_try_dynamic_cast<plus_exprt>(tc_op0))
2684 {
2685 if(skip_typecast(sum->op0()) == tc_op1 && sum->operands().size() == 2)
2686 {
2687 std::optional<exprt> offset;
2688 if(sum->type().id() == ID_pointer)
2689 {
2690 offset = std::move(simplify_pointer_offset(
2691 pointer_offset_exprt{*sum, expr.op0().type()})
2692 .expr);
2693 if(offset->id() == ID_pointer_offset)
2694 return unchanged(expr);
2695 }
2696 else
2697 offset = std::move(
2698 simplify_typecast(typecast_exprt{sum->op1(), expr.op0().type()})
2699 .expr);
2700
2701 exprt offset_op = skip_typecast(*offset);
2702 if(
2703 offset_op.type().id() != ID_signedbv &&
2704 offset_op.type().id() != ID_unsignedbv)
2705 {
2706 return unchanged(expr);
2707 }
2708
2709 const std::size_t width =
2710 to_bitvector_type(expr.op0().type()).get_width();
2711 const integer_bitvector_typet bv_type{op_type_id, width};
2712
2713 or_exprt not_representable{
2715 offset_op,
2716 ID_lt,
2717 from_integer(bv_type.smallest(), offset_op.type())},
2719 offset_op,
2720 ID_gt,
2721 from_integer(bv_type.largest(), offset_op.type())}};
2722
2723 return struct_exprt{
2724 {*offset, simplify_rec(not_representable)}, expr.type()};
2725 }
2726 }
2727 }
2728
2729 if(!expr.op0().is_constant() || !expr.op1().is_constant())
2730 return unchanged(expr);
2731
2732 // preserve the sizeof type annotation
2733 std::optional<typet> c_sizeof_type;
2734 for(const auto &op : expr.operands())
2735 {
2736 const typet &sizeof_type =
2737 static_cast<const typet &>(op.find(ID_C_c_sizeof_type));
2738 if(sizeof_type.is_not_nil())
2739 {
2740 c_sizeof_type = sizeof_type;
2741 break;
2742 }
2743 }
2744
2745 const auto op0_value = numeric_cast<mp_integer>(expr.op0());
2746 const auto op1_value = numeric_cast<mp_integer>(expr.op1());
2747 if(!op0_value.has_value() || !op1_value.has_value())
2748 return unchanged(expr);
2749
2750 mp_integer no_overflow_result;
2751 if(expr.id() == ID_overflow_result_plus)
2752 no_overflow_result = *op0_value + *op1_value;
2753 else if(expr.id() == ID_overflow_result_minus)
2754 no_overflow_result = *op0_value - *op1_value;
2755 else if(expr.id() == ID_overflow_result_mult)
2756 no_overflow_result = *op0_value * *op1_value;
2757 else if(expr.id() == ID_overflow_result_shl)
2758 no_overflow_result = *op0_value << *op1_value;
2759 else
2761
2762 exprt no_overflow_result_expr =
2763 from_integer(no_overflow_result, expr.op0().type());
2764 if(c_sizeof_type.has_value())
2765 no_overflow_result_expr.set(ID_C_c_sizeof_type, *c_sizeof_type);
2766
2767 const std::size_t width = to_bitvector_type(expr.op0().type()).get_width();
2768 const integer_bitvector_typet bv_type{op_type_id, width};
2769 if(
2770 no_overflow_result < bv_type.smallest() ||
2771 no_overflow_result > bv_type.largest())
2772 {
2773 return struct_exprt{
2774 {std::move(no_overflow_result_expr), true_exprt{}}, expr.type()};
2775 }
2776 else
2777 {
2778 return struct_exprt{
2779 {std::move(no_overflow_result_expr), false_exprt{}}, expr.type()};
2780 }
2781 }
2782}
2783
2786{
2787 auto result = unchanged(expr);
2788
2789 // The ifs below could one day be replaced by a switch()
2790
2791 if(expr.id()==ID_address_of)
2792 {
2793 // the argument of this expression needs special treatment
2794 }
2795 else if(expr.id()==ID_if)
2796 {
2797 result = simplify_if_preorder(to_if_expr(expr));
2798 }
2799 else if(expr.id() == ID_typecast)
2800 {
2802 }
2803 else if(
2804 expr.id() == ID_byte_extract_little_endian ||
2805 expr.id() == ID_byte_extract_big_endian)
2806 {
2808 }
2809 else if(expr.id() == ID_dereference)
2810 {
2812 }
2813 else if(expr.id() == ID_index)
2814 {
2815 result = simplify_index_preorder(to_index_expr(expr));
2816 }
2817 else if(expr.id() == ID_member)
2818 {
2820 }
2821 else if(
2822 expr.id() == ID_is_dynamic_object || expr.id() == ID_is_invalid_pointer ||
2823 expr.id() == ID_object_size || expr.id() == ID_pointer_object ||
2824 expr.id() == ID_pointer_offset)
2825 {
2827 }
2828 else if(expr.has_operands())
2829 {
2830 std::optional<exprt::operandst> new_operands;
2831
2832 for(std::size_t i = 0; i < expr.operands().size(); ++i)
2833 {
2834 auto r_it = simplify_rec(expr.operands()[i]); // recursive call
2835 if(r_it.has_changed())
2836 {
2837 if(!new_operands.has_value())
2838 new_operands = expr.operands();
2839 (*new_operands)[i] = std::move(r_it.expr);
2840 }
2841 }
2842
2843 if(new_operands.has_value())
2844 {
2845 std::swap(result.expr.operands(), *new_operands);
2846 result.expr_changed = resultt<>::CHANGED;
2847 }
2848 }
2849
2850 if(as_const(result.expr).type().id() == ID_array)
2851 {
2852 const array_typet &array_type = to_array_type(as_const(result.expr).type());
2853 resultt<> simp_size = simplify_rec(array_type.size());
2854 if(simp_size.has_changed())
2855 {
2856 to_array_type(result.expr.type()).size() = simp_size.expr;
2857 result.expr_changed = resultt<>::CHANGED;
2858 }
2859 }
2860
2861 return result;
2862}
2863
2865{
2866 if(!node.has_operands())
2867 return unchanged(node); // no change
2868
2869 // #define DEBUGX
2870
2871#ifdef DEBUGX
2872 exprt old(node);
2873#endif
2874
2875 exprt expr = node;
2876 bool no_change_join_operands = join_operands(expr);
2877
2878 resultt<> r = unchanged(expr);
2879
2880 if(expr.id()==ID_typecast)
2881 {
2883 }
2884 else if(expr.id()==ID_equal || expr.id()==ID_notequal ||
2885 expr.id()==ID_gt || expr.id()==ID_lt ||
2886 expr.id()==ID_ge || expr.id()==ID_le)
2887 {
2889 }
2890 else if(expr.id()==ID_if)
2891 {
2892 r = simplify_if(to_if_expr(expr));
2893 }
2894 else if(expr.id()==ID_lambda)
2895 {
2897 }
2898 else if(expr.id()==ID_with)
2899 {
2900 r = simplify_with(to_with_expr(expr));
2901 }
2902 else if(expr.id()==ID_update)
2903 {
2905 }
2906 else if(expr.id()==ID_index)
2907 {
2909 }
2910 else if(expr.id()==ID_member)
2911 {
2913 }
2914 else if(expr.id()==ID_byte_update_little_endian ||
2915 expr.id()==ID_byte_update_big_endian)
2916 {
2918 }
2919 else if(expr.id()==ID_byte_extract_little_endian ||
2920 expr.id()==ID_byte_extract_big_endian)
2921 {
2923 }
2924 else if(expr.id()==ID_pointer_object)
2925 {
2927 }
2928 else if(expr.id() == ID_is_dynamic_object)
2929 {
2931 }
2932 else if(expr.id() == ID_is_invalid_pointer)
2933 {
2935 }
2936 else if(
2938 {
2940 }
2941 else if(expr.id()==ID_div)
2942 {
2943 r = simplify_div(to_div_expr(expr));
2944 }
2945 else if(expr.id()==ID_mod)
2946 {
2947 r = simplify_mod(to_mod_expr(expr));
2948 }
2949 else if(expr.id()==ID_bitnot)
2950 {
2952 }
2953 else if(
2954 expr.id() == ID_bitand || expr.id() == ID_bitor || expr.id() == ID_bitxor ||
2955 expr.id() == ID_bitxnor)
2956 {
2958 }
2959 else if(expr.id()==ID_ashr || expr.id()==ID_lshr || expr.id()==ID_shl)
2960 {
2962 }
2963 else if(expr.id()==ID_power)
2964 {
2966 }
2967 else if(expr.id()==ID_plus)
2968 {
2969 r = simplify_plus(to_plus_expr(expr));
2970 }
2971 else if(expr.id()==ID_minus)
2972 {
2974 }
2975 else if(expr.id()==ID_mult)
2976 {
2977 r = simplify_mult(to_mult_expr(expr));
2978 }
2979 else if(expr.id()==ID_floatbv_plus ||
2980 expr.id()==ID_floatbv_minus ||
2981 expr.id()==ID_floatbv_mult ||
2982 expr.id()==ID_floatbv_div)
2983 {
2985 }
2986 else if(expr.id()==ID_floatbv_typecast)
2987 {
2989 }
2990 else if(expr.id()==ID_unary_minus)
2991 {
2993 }
2994 else if(expr.id()==ID_unary_plus)
2995 {
2997 }
2998 else if(expr.id()==ID_not)
2999 {
3000 r = simplify_not(to_not_expr(expr));
3001 }
3002 else if(expr.id()==ID_implies ||
3003 expr.id()==ID_or || expr.id()==ID_xor ||
3004 expr.id()==ID_and)
3005 {
3006 r = simplify_boolean(expr);
3007 }
3008 else if(expr.id()==ID_dereference)
3009 {
3011 }
3012 else if(expr.id()==ID_address_of)
3013 {
3015 }
3016 else if(expr.id()==ID_pointer_offset)
3017 {
3019 }
3020 else if(expr.id()==ID_extractbit)
3021 {
3023 }
3024 else if(expr.id()==ID_concatenation)
3025 {
3027 }
3028 else if(expr.id()==ID_extractbits)
3029 {
3031 }
3032 else if(expr.id() == ID_zero_extend)
3033 {
3035 }
3036 else if(expr.id()==ID_ieee_float_equal ||
3037 expr.id()==ID_ieee_float_notequal)
3038 {
3040 }
3041 else if(expr.id() == ID_bswap)
3042 {
3044 }
3045 else if(expr.id()==ID_isinf)
3046 {
3048 }
3049 else if(expr.id()==ID_isnan)
3050 {
3052 }
3053 else if(expr.id()==ID_isnormal)
3054 {
3056 }
3057 else if(expr.id()==ID_abs)
3058 {
3059 r = simplify_abs(to_abs_expr(expr));
3060 }
3061 else if(expr.id()==ID_sign)
3062 {
3063 r = simplify_sign(to_sign_expr(expr));
3064 }
3065 else if(expr.id() == ID_popcount)
3066 {
3068 }
3069 else if(expr.id() == ID_count_leading_zeros)
3070 {
3072 }
3073 else if(expr.id() == ID_count_trailing_zeros)
3074 {
3076 }
3077 else if(expr.id() == ID_find_first_set)
3078 {
3080 }
3081 else if(expr.id() == ID_function_application)
3082 {
3084 }
3085 else if(expr.id() == ID_complex_real || expr.id() == ID_complex_imag)
3086 {
3088 }
3089 else if(
3090 const auto binary_overflow =
3092 {
3093 r = simplify_overflow_binary(*binary_overflow);
3094 }
3095 else if(
3096 const auto unary_overflow =
3098 {
3099 r = simplify_overflow_unary(*unary_overflow);
3100 }
3101 else if(
3102 const auto overflow_result =
3104 {
3105 r = simplify_overflow_result(*overflow_result);
3106 }
3107 else if(expr.id() == ID_bitreverse)
3108 {
3110 }
3111 else if(
3112 const auto prophecy_r_or_w_ok =
3114 {
3115 r = simplify_prophecy_r_or_w_ok(*prophecy_r_or_w_ok);
3116 }
3117 else if(
3118 const auto prophecy_pointer_in_range =
3120 {
3121 r = simplify_prophecy_pointer_in_range(*prophecy_pointer_in_range);
3122 }
3123
3124 if(!no_change_join_operands)
3125 r = changed(r);
3126
3127#ifdef DEBUGX
3128 if(
3129 r.has_changed()
3130# ifdef DEBUG_ON_DEMAND
3131 && debug_on
3132# endif
3133 )
3134 {
3135 std::cout << "===== " << node.id() << ": " << format(node) << '\n'
3136 << " ---> " << format(r.expr) << '\n';
3137 }
3138#endif
3139
3140 return r;
3141}
3142
3144{
3145 // look up in cache
3146
3147 #ifdef USE_CACHE
3148 std::pair<simplify_expr_cachet::containert::iterator, bool>
3149 cache_result=simplify_expr_cache.container().
3150 insert(std::pair<exprt, exprt>(expr, exprt()));
3151
3152 if(!cache_result.second) // found!
3153 {
3154 const exprt &new_expr=cache_result.first->second;
3155
3156 if(new_expr.id().empty())
3157 return true; // no change
3158
3159 expr=new_expr;
3160 return false;
3161 }
3162 #endif
3163
3164 // We work on a copy to prevent unnecessary destruction of sharing.
3165 auto simplify_node_preorder_result = simplify_node_preorder(expr);
3166
3167 auto simplify_node_result = simplify_node(simplify_node_preorder_result.expr);
3168
3169 if(
3170 !simplify_node_result.has_changed() &&
3171 simplify_node_preorder_result.has_changed())
3172 {
3173 simplify_node_result.expr_changed =
3174 simplify_node_preorder_result.expr_changed;
3175 }
3176
3177#ifdef USE_LOCAL_REPLACE_MAP
3178 exprt tmp = simplify_node_result.expr;
3179# if 1
3180 replace_mapt::const_iterator it =
3181 local_replace_map.find(simplify_node_result.expr);
3182 if(it!=local_replace_map.end())
3183 simplify_node_result = changed(it->second);
3184# else
3185 if(
3186 !local_replace_map.empty() &&
3187 !replace_expr(local_replace_map, simplify_node_result.expr))
3188 {
3189 simplify_node_result = changed(simplify_rec(simplify_node_result.expr));
3190 }
3191# endif
3192#endif
3193
3194 if(!simplify_node_result.has_changed())
3195 {
3196 return unchanged(expr);
3197 }
3198 else
3199 {
3201 (as_const(simplify_node_result.expr).type().id() == ID_array &&
3202 expr.type().id() == ID_array) ||
3203 as_const(simplify_node_result.expr).type() == expr.type(),
3204 simplify_node_result.expr.pretty(),
3205 expr.pretty());
3206
3207#ifdef USE_CACHE
3208 // save in cache
3209 cache_result.first->second = simplify_node_result.expr;
3210#endif
3211
3212 return simplify_node_result;
3213 }
3214}
3215
3218{
3219#ifdef DEBUG_ON_DEMAND
3220 if(debug_on)
3221 std::cout << "TO-SIMP " << format(expr) << "\n";
3222#endif
3223 auto result = simplify_rec(expr);
3224#ifdef DEBUG_ON_DEMAND
3225 if(debug_on)
3226 std::cout << "FULLSIMP " << format(result.expr) << "\n";
3227#endif
3228 if(result.has_changed())
3229 {
3230 expr = result.expr;
3231 return false; // change
3232 }
3233 else
3234 return true; // no change
3235}
3236
3238bool simplify(exprt &expr, const namespacet &ns)
3239{
3240 return simplify_exprt(ns).simplify(expr);
3241}
3242
3244{
3245 simplify_exprt(ns).simplify(src);
3246 return src;
3247}
configt config
Definition config.cpp:25
mp_integer bvrep2integer(const irep_idt &src, std::size_t width, bool is_signed)
convert a bit-vector representation (possibly signed) to integer
constant_exprt from_integer(const mp_integer &int_value, const typet &type)
bool to_integer(const constant_exprt &expr, mp_integer &int_value)
Convert a constant expression expr to an arbitrary-precision integer.
bool get_bvrep_bit(const irep_idt &src, std::size_t width, std::size_t bit_index)
Get a bit with given index from bit-vector representation.
mp_integer power(const mp_integer &base, const mp_integer &exponent)
A multi-precision implementation of the power operator.
Target numeric_cast_v(const mp_integer &arg)
Convert an mp_integer to integral type Target An invariant will fail if the conversion is not possibl...
std::optional< Target > numeric_cast(const exprt &arg)
Converts an expression to any integral type.
const T & as_const(T &value)
Return a reference to the same object but ensures the type is const.
Definition as_const.h:14
API to expression classes for bitvectors.
bool can_cast_expr< mult_overflow_exprt >(const exprt &base)
const shift_exprt & to_shift_expr(const exprt &expr)
Cast an exprt to a shift_exprt.
const popcount_exprt & to_popcount_expr(const exprt &expr)
Cast an exprt to a popcount_exprt.
const extractbits_exprt & to_extractbits_expr(const exprt &expr)
Cast an exprt to an extractbits_exprt.
bool can_cast_expr< minus_overflow_exprt >(const exprt &base)
const find_first_set_exprt & to_find_first_set_expr(const exprt &expr)
Cast an exprt to a find_first_set_exprt.
bool can_cast_expr< shl_overflow_exprt >(const exprt &base)
const bitnot_exprt & to_bitnot_expr(const exprt &expr)
Cast an exprt to a bitnot_exprt.
const bswap_exprt & to_bswap_expr(const exprt &expr)
Cast an exprt to a bswap_exprt.
bool can_cast_expr< plus_overflow_exprt >(const exprt &base)
const count_leading_zeros_exprt & to_count_leading_zeros_expr(const exprt &expr)
Cast an exprt to a count_leading_zeros_exprt.
const bitreverse_exprt & to_bitreverse_expr(const exprt &expr)
Cast an exprt to a bitreverse_exprt.
const extractbit_exprt & to_extractbit_expr(const exprt &expr)
Cast an exprt to an extractbit_exprt.
bool can_cast_expr< unary_minus_overflow_exprt >(const exprt &base)
const concatenation_exprt & to_concatenation_expr(const exprt &expr)
Cast an exprt to a concatenation_exprt.
const zero_extend_exprt & to_zero_extend_expr(const exprt &expr)
Cast an exprt to a zero_extend_exprt.
const count_trailing_zeros_exprt & to_count_trailing_zeros_expr(const exprt &expr)
Cast an exprt to a count_trailing_zeros_exprt.
const bv_typet & to_bv_type(const typet &type)
Cast a typet to a bv_typet.
const fixedbv_typet & to_fixedbv_type(const typet &type)
Cast a typet to a fixedbv_typet.
const bitvector_typet & to_bitvector_type(const typet &type)
Cast a typet to a bitvector_typet.
const floatbv_typet & to_floatbv_type(const typet &type)
Cast a typet to a floatbv_typet.
void slice(symex_bmct &symex, symex_target_equationt &symex_target_equation, const namespacet &ns, const optionst &options, ui_message_handlert &ui_message_handler)
Definition bmc_util.cpp:198
Expression classes for byte-level operators.
const byte_update_exprt & to_byte_update_expr(const exprt &expr)
exprt lower_byte_extract(const byte_extract_exprt &src, const namespacet &ns)
Rewrite a byte extract expression to more fundamental operations.
const byte_extract_exprt & to_byte_extract_expr(const exprt &expr)
int16_t s2
int8_t s1
unsignedbv_typet size_type()
Definition c_types.cpp:50
pointer_typet pointer_type(const typet &subtype)
Definition c_types.cpp:235
const c_enum_typet & to_c_enum_type(const typet &type)
Cast a typet to a c_enum_typet.
Definition c_types.h:335
const c_enum_tag_typet & to_c_enum_tag_type(const typet &type)
Cast a typet to a c_enum_tag_typet.
Definition c_types.h:377
const union_typet & to_union_type(const typet &type)
Cast a typet to a union_typet.
Definition c_types.h:184
const union_tag_typet & to_union_tag_type(const typet &type)
Cast a typet to a union_tag_typet.
Definition c_types.h:224
Absolute value.
Definition std_expr.h:442
Operator to return the address of an object.
Array constructor from list of elements.
Definition std_expr.h:1621
exprt & what()
Definition std_expr.h:1575
Arrays with given size.
Definition std_types.h:807
const exprt & size() const
Definition std_types.h:840
const typet & element_type() const
The type of the elements of the array.
Definition std_types.h:827
A base class for binary expressions.
Definition std_expr.h:638
exprt & op0()
Definition expr.h:133
exprt & op1()
Definition expr.h:136
A Boolean expression returning true, iff operation kind would result in an overflow when applied to o...
A base class for relations, i.e., binary predicates whose two operands have the same type.
Definition std_expr.h:762
std::size_t get_width() const
Definition std_types.h:925
Expression of type type extracted from some object op starting at position offset (given in number of...
std::size_t get_bits_per_byte() const
Expression corresponding to op() where the bytes starting at position offset (given in number of byte...
const exprt & offset() const
void set_offset(exprt e)
const exprt & op() const
void set_op(exprt e)
std::size_t get_bits_per_byte() const
const exprt & value() const
The C/C++ Booleans.
Definition c_types.h:97
C enum tag type, i.e., c_enum_typet with an identifier.
Definition c_types.h:352
const typet & underlying_type() const
Definition c_types.h:307
Determine whether an expression is constant.
Definition expr_util.h:91
exprt real()
Definition std_expr.h:1927
exprt imag()
Definition std_expr.h:1937
struct configt::ansi_ct ansi_c
A constant literal expression.
Definition std_expr.h:2995
const irep_idt & get_value() const
Definition std_expr.h:3003
void set_value(const irep_idt &value)
Definition std_expr.h:3008
bool is_null_pointer() const
Returns true if expr has a pointer type and a value NULL; it also returns true when expr has value ze...
Definition std_expr.cpp:25
The count leading zeros (counting the number of zero bits starting from the most-significant bit) exp...
The count trailing zeros (counting the number of zero bits starting from the least-significant bit) e...
Operator to dereference a pointer.
dstringt has one field, an unsigned integer no which is an index into a static table of strings.
Definition dstring.h:38
bool empty() const
Definition dstring.h:89
Union constructor to support unions without any member (a GCC/Clang feature).
Definition std_expr.h:1834
Base class for all expressions.
Definition expr.h:56
std::vector< exprt > operandst
Definition expr.h:58
bool is_one() const
Return whether the expression is a constant representing 1.
Definition expr.cpp:96
bool has_operands() const
Return true if there is at least one operand.
Definition expr.h:91
bool is_true() const
Return whether the expression is a constant representing true.
Definition expr.cpp:27
bool is_false() const
Return whether the expression is a constant representing false.
Definition expr.cpp:34
bool is_zero() const
Return whether the expression is a constant representing 0.
Definition expr.cpp:47
exprt & op0()
Definition expr.h:133
exprt & op1()
Definition expr.h:136
bool is_constant() const
Return whether the expression is a constant.
Definition expr.h:212
typet & type()
Return the type of the expression.
Definition expr.h:84
operandst & operands()
Definition expr.h:94
const source_locationt & source_location() const
Definition expr.h:231
source_locationt & add_source_location()
Definition expr.h:236
void add_to_operands(const exprt &expr)
Add the given argument to the end of exprt's operands.
Definition expr.h:170
The Boolean constant false.
Definition std_expr.h:3077
Returns one plus the index of the least-significant one bit, or zero if the operand is zero.
std::size_t get_fraction_bits() const
Definition fixedbv.h:35
Fixed-width bit-vector with signed fixed-point interpretation.
fixedbv_spect spec
Definition fixedbv.h:44
void from_integer(const mp_integer &i)
Definition fixedbv.cpp:32
mp_integer to_integer() const
Definition fixedbv.cpp:37
void set_value(const mp_integer &_v)
Definition fixedbv.h:96
void round(const fixedbv_spect &dest_spec)
Definition fixedbv.cpp:52
constant_exprt to_expr() const
Definition fixedbv.cpp:43
Fixed-width bit-vector with IEEE floating-point interpretation.
Application of (mathematical) function.
void unpack(const mp_integer &i)
ieee_float_spect spec
Definition ieee_float.h:134
mp_integer to_integer() const
constant_exprt to_expr() const
bool get_sign() const
Definition ieee_float.h:247
void set_sign(bool _sign)
Definition ieee_float.h:183
void from_integer(const mp_integer &i)
mp_integer pack() const
void change_spec(const ieee_float_spect &dest_spec)
The trinary if-then-else operator.
Definition std_expr.h:2375
exprt & false_case()
Definition std_expr.h:2412
exprt & true_case()
Definition std_expr.h:2402
Array index operator.
Definition std_expr.h:1470
exprt & index()
Definition std_expr.h:1510
exprt & array()
Definition std_expr.h:1500
Fixed-width bit-vector representing a signed or unsigned integer.
std::string pretty(unsigned indent=0, unsigned max_indent=0) const
Definition irep.cpp:482
const irept & find(const irep_idt &name) const
Definition irep.cpp:93
const irep_idt & get(const irep_idt &name) const
Definition irep.cpp:44
void set(const irep_idt &name, const irep_idt &value)
Definition irep.h:412
bool is_not_nil() const
Definition irep.h:372
void make_nil()
Definition irep.h:446
void swap(irept &irep)
Definition irep.h:434
const irep_idt & id() const
Definition irep.h:388
bool is_nil() const
Definition irep.h:368
A (mathematical) lambda expression.
exprt application(const operandst &arguments) const
Extract member of struct or union.
Definition std_expr.h:2849
Binary multiplication Associativity is not specified.
Definition std_expr.h:1107
const union_typet & follow_tag(const union_tag_typet &) const
Follow type tag of union type.
Definition namespace.cpp:63
A namespacet is essentially one or two symbol tables bound together, to allow for symbol lookups in t...
Definition namespace.h:94
The NIL expression.
Definition std_expr.h:3086
The null pointer constant.
Boolean OR.
Definition std_expr.h:2233
An expression returning both the result of the arithmetic operation under wrap-around semantics as we...
exprt & op0()
Definition expr.h:133
exprt & op1()
Definition expr.h:136
The plus expression Associativity is not specified.
Definition std_expr.h:1002
The offset (in bytes) of a pointer relative to the object.
The popcount (counting the number of bits set to 1) expression.
const exprt & length() const
const exprt & content() const
Sign of an expression Predicate is true if _op is negative, false otherwise.
Definition std_expr.h:596
Fixed-width bit-vector with two's complement interpretation.
resultt simplify_isnan(const unary_exprt &)
resultt simplify_bitwise(const multi_ary_exprt &)
const namespacet & ns
resultt simplify_div(const div_exprt &)
resultt simplify_byte_extract(const byte_extract_exprt &)
resultt simplify_bitreverse(const bitreverse_exprt &)
Try to simplify bit-reversing to a constant expression.
resultt simplify_abs(const abs_exprt &)
resultt simplify_isnormal(const unary_exprt &)
resultt simplify_dereference(const dereference_exprt &)
resultt simplify_bitnot(const bitnot_exprt &)
resultt simplify_zero_extend(const zero_extend_exprt &)
resultt simplify_prophecy_r_or_w_ok(const prophecy_r_or_w_ok_exprt &)
Try to simplify prophecy_{r,w,rw}_ok to a constant expression.
resultt simplify_member_preorder(const member_exprt &)
resultt simplify_popcount(const popcount_exprt &)
static resultt changed(resultt<> result)
resultt simplify_dereference_preorder(const dereference_exprt &)
resultt simplify_unary_pointer_predicate_preorder(const unary_exprt &)
resultt simplify_address_of(const address_of_exprt &)
resultt simplify_if(const if_exprt &)
resultt simplify_node(const exprt &)
resultt simplify_node_preorder(const exprt &)
resultt simplify_prophecy_pointer_in_range(const prophecy_pointer_in_range_exprt &)
Try to simplify prophecy_pointer_in_range to a constant expression.
resultt simplify_overflow_unary(const unary_overflow_exprt &)
Try to simplify overflow-unary-.
resultt simplify_minus(const minus_exprt &)
resultt simplify_extractbit(const extractbit_exprt &)
resultt simplify_rec(const exprt &)
resultt simplify_shifts(const shift_exprt &)
resultt simplify_index_preorder(const index_exprt &)
resultt simplify_typecast(const typecast_exprt &)
resultt simplify_pointer_object(const pointer_object_exprt &)
resultt simplify_boolean(const exprt &)
resultt simplify_object(const exprt &)
resultt simplify_mult(const mult_exprt &)
resultt simplify_floatbv_typecast(const floatbv_typecast_exprt &)
resultt simplify_with(const with_exprt &)
resultt simplify_inequality(const binary_relation_exprt &)
simplifies inequalities !=, <=, <, >=, >, and also ==
resultt simplify_not(const not_exprt &)
resultt simplify_isinf(const unary_exprt &)
resultt simplify_overflow_binary(const binary_overflow_exprt &)
Try to simplify overflow-+, overflow-*, overflow–, overflow-shl.
resultt simplify_function_application(const function_application_exprt &)
Attempt to simplify mathematical function applications if we have enough information to do so.
resultt simplify_index(const index_exprt &)
resultt simplify_bswap(const bswap_exprt &)
resultt simplify_member(const member_exprt &)
static resultt unchanged(exprt expr)
resultt simplify_byte_update(const byte_update_exprt &)
resultt simplify_extractbits(const extractbits_exprt &)
Simplifies extracting of bits from a constant.
resultt simplify_update(const update_exprt &)
resultt simplify_is_invalid_pointer(const unary_exprt &)
resultt simplify_mod(const mod_exprt &)
resultt simplify_complex(const unary_exprt &)
resultt simplify_pointer_offset(const pointer_offset_exprt &)
resultt simplify_plus(const plus_exprt &)
virtual bool simplify(exprt &expr)
resultt simplify_unary_plus(const unary_plus_exprt &)
resultt simplify_overflow_result(const overflow_result_exprt &)
Try to simplify overflow_result-+, overflow_result-*, overflow_result–, overflow_result-shl,...
resultt simplify_ffs(const find_first_set_exprt &)
Try to simplify find-first-set to a constant expression.
resultt simplify_if_preorder(const if_exprt &expr)
resultt simplify_byte_extract_preorder(const byte_extract_exprt &)
resultt simplify_is_dynamic_object(const unary_exprt &)
resultt simplify_power(const power_exprt &)
resultt simplify_object_size(const object_size_exprt &)
resultt simplify_lambda(const lambda_exprt &)
resultt simplify_concatenation(const concatenation_exprt &)
resultt simplify_floatbv_op(const ieee_float_op_exprt &)
resultt simplify_ctz(const count_trailing_zeros_exprt &)
Try to simplify count-trailing-zeros to a constant expression.
resultt simplify_clz(const count_leading_zeros_exprt &)
Try to simplify count-leading-zeros to a constant expression.
resultt simplify_ieee_float_relation(const binary_relation_exprt &)
resultt simplify_typecast_preorder(const typecast_exprt &)
resultt simplify_sign(const sign_exprt &)
resultt simplify_unary_minus(const unary_minus_exprt &)
Struct constructor from list of elements.
Definition std_expr.h:1877
Structure type, corresponds to C style structs.
Definition std_types.h:231
const componentst & components() const
Definition std_types.h:147
std::vector< componentt > componentst
Definition std_types.h:140
const componentt & get_component(const irep_idt &component_name) const
Get the reference to a component with given name.
Definition std_types.cpp:64
bool has_component(const irep_idt &component_name) const
Definition std_types.h:157
std::size_t component_number(const irep_idt &component_name) const
Return the sequence number of the component with given name.
Definition std_types.cpp:47
const irep_idt & get_identifier() const
Definition std_expr.h:160
The Boolean constant true.
Definition std_expr.h:3068
const typet & subtype() const
Definition type.h:187
Semantic type conversion.
Definition std_expr.h:2073
static exprt conditional_cast(const exprt &expr, const typet &type)
Definition std_expr.h:2081
The type of an expression, extends irept.
Definition type.h:29
Generic base class for unary expressions.
Definition std_expr.h:361
const exprt & op() const
Definition std_expr.h:391
A Boolean expression returning true, iff operation kind would result in an overflow when applied to t...
Union constructor from single element.
Definition std_expr.h:1770
The union type.
Definition c_types.h:147
std::optional< std::pair< struct_union_typet::componentt, mp_integer > > find_widest_union_component(const namespacet &ns) const
Determine the member of maximum bit width in a union type.
Definition c_types.cpp:300
Fixed-width bit-vector with unsigned binary interpretation.
Operator to update elements in structs and arrays.
Definition std_expr.h:2660
exprt & old()
Definition std_expr.h:2672
exprt::operandst & designator()
Definition std_expr.h:2686
exprt & new_value()
Definition std_expr.h:2696
Operator to update elements in structs and arrays.
Definition std_expr.h:2476
exprt & new_value()
Definition std_expr.h:2506
exprt & where()
Definition std_expr.h:2496
exprt & old()
Definition std_expr.h:2486
#define Forall_operands(it, expr)
Definition expr.h:27
auto expr_checked_cast(TExpr &base) -> typename detail::expr_dynamic_cast_return_typet< T, TExpr >::type
Cast a reference to a generic exprt to a specific derived class.
Definition expr_cast.h:227
auto expr_try_dynamic_cast(TExpr &base) -> typename detail::expr_try_dynamic_cast_return_typet< T, TExpr >::type
Try to cast a reference to a generic exprt to a specific derived class.
Definition expr_cast.h:81
constant_exprt make_boolean_expr(bool value)
returns true_exprt if given true and false_exprt otherwise
exprt is_not_zero(const exprt &src, const namespacet &ns)
converts a scalar/float expression to C/C++ Booleans
Definition expr_util.cpp:74
const exprt & skip_typecast(const exprt &expr)
find the expression nested inside typecasts, if any
if_exprt lift_if(const exprt &src, std::size_t operand_number)
lift up an if_exprt one level
bool has_subtype(const typet &type, const std::function< bool(const typet &)> &pred, const namespacet &ns)
returns true if any of the contained types satisfies pred
Deprecated expression utility functions.
API to expression classes for floating-point arithmetic.
const ieee_float_op_exprt & to_ieee_float_op_expr(const exprt &expr)
Cast an exprt to an ieee_float_op_exprt.
const floatbv_typecast_exprt & to_floatbv_typecast_expr(const exprt &expr)
Cast an exprt to a floatbv_typecast_exprt.
static format_containert< T > format(const T &o)
Definition format.h:37
const std::string & id2string(const irep_idt &d)
Definition irep.h:44
static int8_t r
Definition irep_hash.h:60
API to expression classes for 'mathematical' expressions.
const power_exprt & to_power_expr(const exprt &expr)
Cast an exprt to a power_exprt.
const function_application_exprt & to_function_application_expr(const exprt &expr)
Cast an exprt to a function_application_exprt.
const lambda_exprt & to_lambda_expr(const exprt &expr)
Cast an exprt to a lambda_exprt.
const mp_integer string2integer(const std::string &n, unsigned base)
Definition mp_arith.cpp:54
API to expression classes for Pointers.
const address_of_exprt & to_address_of_expr(const exprt &expr)
Cast an exprt to an address_of_exprt.
const pointer_typet & to_pointer_type(const typet &type)
Cast a typet to a pointer_typet.
const dereference_exprt & to_dereference_expr(const exprt &expr)
Cast an exprt to a dereference_exprt.
const pointer_offset_exprt & to_pointer_offset_expr(const exprt &expr)
Cast an exprt to a pointer_offset_exprt.
const pointer_object_exprt & to_pointer_object_expr(const exprt &expr)
Cast an exprt to a pointer_object_exprt.
std::optional< mp_integer > pointer_offset_size(const typet &type, const namespacet &ns)
Compute the size of a type in bytes, rounding up to full bytes.
std::optional< exprt > get_subexpression_at_offset(const exprt &expr, const mp_integer &offset_bytes, const typet &target_type_raw, const namespacet &ns)
std::optional< mp_integer > pointer_offset_bits(const typet &type, const namespacet &ns)
std::optional< mp_integer > member_offset(const struct_typet &type, const irep_idt &member, const namespacet &ns)
std::optional< exprt > member_offset_expr(const member_exprt &member_expr, const namespacet &ns)
Pointer Logic.
exprt pointer_offset_sum(const exprt &a, const exprt &b)
Pointer Dereferencing.
exprt object_size(const exprt &pointer)
constant_exprt from_rational(const rationalt &a)
bool replace_expr(const exprt &what, const exprt &by, exprt &dest)
bool simplify(exprt &expr, const namespacet &ns)
static simplify_exprt::resultt simplify_string_compare_to(const function_application_exprt &expr, const namespacet &ns)
Simplify String.compareTo function when arguments are constant.
static simplify_exprt::resultt simplify_string_contains(const function_application_exprt &expr, const namespacet &ns)
Simplify String.contains function when arguments are constant.
static simplify_exprt::resultt simplify_string_endswith(const function_application_exprt &expr, const namespacet &ns)
Simplify String.endsWith function when arguments are constant.
static simplify_exprt::resultt simplify_string_char_at(const function_application_exprt &expr, const namespacet &ns)
Simplify String.charAt function when arguments are constant.
static simplify_exprt::resultt simplify_string_startswith(const function_application_exprt &expr, const namespacet &ns)
Simplify String.startsWith function when arguments are constant.
static simplify_exprt::resultt simplify_string_is_empty(const function_application_exprt &expr, const namespacet &ns)
Simplify String.isEmpty function when arguments are constant.
static bool lower_case_string_expression(array_exprt &string_data)
Take the passed-in constant string array and lower-case every character.
static simplify_exprt::resultt simplify_string_index_of(const function_application_exprt &expr, const namespacet &ns, const bool search_from_end)
Simplify String.indexOf function when arguments are constant.
static simplify_exprt::resultt simplify_string_equals_ignore_case(const function_application_exprt &expr, const namespacet &ns)
Simplify String.equalsIgnorecase function when arguments are constant.
exprt simplify_expr(exprt src, const namespacet &ns)
std::optional< exprt > bits2expr(const std::string &bits, const typet &type, bool little_endian, const namespacet &ns)
std::optional< std::string > expr2bits(const exprt &expr, bool little_endian, const namespacet &ns)
std::optional< std::reference_wrapper< const array_exprt > > try_get_string_data_array(const exprt &content, const namespacet &ns)
Get char sequence from content field of a refined string expression.
bool join_operands(exprt &expr)
BigInt mp_integer
Definition smt_terms.h:17
#define CHECK_RETURN(CONDITION)
Definition invariant.h:495
#define UNREACHABLE
This should be used to mark dead code.
Definition invariant.h:525
#define DATA_INVARIANT(CONDITION, REASON)
This condition should be used to document that assumptions that are made on goto_functions,...
Definition invariant.h:534
#define POSTCONDITION_WITH_DIAGNOSTICS(CONDITION,...)
Definition invariant.h:480
auto component(T &struct_expr, const irep_idt &name, const namespacet &ns) -> decltype(struct_expr.op0())
Definition std_expr.cpp:97
API to expression classes.
const struct_exprt & to_struct_expr(const exprt &expr)
Cast an exprt to a struct_exprt.
Definition std_expr.h:1900
const array_of_exprt & to_array_of_expr(const exprt &expr)
Cast an exprt to an array_of_exprt.
Definition std_expr.h:1603
const binary_relation_exprt & to_binary_relation_expr(const exprt &expr)
Cast an exprt to a binary_relation_exprt.
Definition std_expr.h:895
const unary_plus_exprt & to_unary_plus_expr(const exprt &expr)
Cast an exprt to a unary_plus_exprt.
Definition std_expr.h:556
const index_exprt & to_index_expr(const exprt &expr)
Cast an exprt to an index_exprt.
Definition std_expr.h:1538
const mod_exprt & to_mod_expr(const exprt &expr)
Cast an exprt to a mod_exprt.
Definition std_expr.h:1277
const mult_exprt & to_mult_expr(const exprt &expr)
Cast an exprt to a mult_exprt.
Definition std_expr.h:1137
const array_exprt & to_array_expr(const exprt &expr)
Cast an exprt to an array_exprt.
Definition std_expr.h:1665
const typecast_exprt & to_typecast_expr(const exprt &expr)
Cast an exprt to a typecast_exprt.
Definition std_expr.h:2107
const div_exprt & to_div_expr(const exprt &expr)
Cast an exprt to a div_exprt.
Definition std_expr.h:1206
const plus_exprt & to_plus_expr(const exprt &expr)
Cast an exprt to a plus_exprt.
Definition std_expr.h:1041
const unary_exprt & to_unary_expr(const exprt &expr)
Cast an exprt to a unary_exprt.
Definition std_expr.h:426
const multi_ary_exprt & to_multi_ary_expr(const exprt &expr)
Cast an exprt to a multi_ary_exprt.
Definition std_expr.h:987
const abs_exprt & to_abs_expr(const exprt &expr)
Cast an exprt to a abs_exprt.
Definition std_expr.h:466
const if_exprt & to_if_expr(const exprt &expr)
Cast an exprt to an if_exprt.
Definition std_expr.h:2455
const member_exprt & to_member_expr(const exprt &expr)
Cast an exprt to a member_exprt.
Definition std_expr.h:2941
const minus_exprt & to_minus_expr(const exprt &expr)
Cast an exprt to a minus_exprt.
Definition std_expr.h:1086
const complex_imag_exprt & to_complex_imag_expr(const exprt &expr)
Cast an exprt to a complex_imag_exprt.
Definition std_expr.h:2053
const index_designatort & to_index_designator(const exprt &expr)
Cast an exprt to an index_designatort.
Definition std_expr.h:2591
const complex_real_exprt & to_complex_real_expr(const exprt &expr)
Cast an exprt to a complex_real_exprt.
Definition std_expr.h:2010
const constant_exprt & to_constant_expr(const exprt &expr)
Cast an exprt to a constant_exprt.
Definition std_expr.h:3050
const not_exprt & to_not_expr(const exprt &expr)
Cast an exprt to an not_exprt.
Definition std_expr.h:2357
const symbol_exprt & to_symbol_expr(const exprt &expr)
Cast an exprt to a symbol_exprt.
Definition std_expr.h:272
const with_exprt & to_with_expr(const exprt &expr)
Cast an exprt to a with_exprt.
Definition std_expr.h:2538
const complex_exprt & to_complex_expr(const exprt &expr)
Cast an exprt to a complex_exprt.
Definition std_expr.h:1965
const update_exprt & to_update_expr(const exprt &expr)
Cast an exprt to an update_exprt.
Definition std_expr.h:2743
const unary_minus_exprt & to_unary_minus_expr(const exprt &expr)
Cast an exprt to a unary_minus_exprt.
Definition std_expr.h:514
const sign_exprt & to_sign_expr(const exprt &expr)
Cast an exprt to a sign_exprt.
Definition std_expr.h:621
const struct_typet & to_struct_type(const typet &type)
Cast a typet to a struct_typet.
Definition std_types.h:308
const struct_tag_typet & to_struct_tag_type(const typet &type)
Cast a typet to a struct_tag_typet.
Definition std_types.h:518
const array_typet & to_array_type(const typet &type)
Cast a typet to an array_typet.
Definition std_types.h:888
String expressions for the string solver.
refined_string_exprt & to_string_expr(exprt &expr)
bool can_cast_expr< refined_string_exprt >(const exprt &base)
endiannesst endianness
Definition config.h:209
bool NULL_is_zero
Definition config.h:226
static bool failed(bool error_indicator)
const type_with_subtypet & to_type_with_subtype(const typet &type)
Definition type.h:208