1 |
|
/****************************************************************************** |
2 |
|
* Top contributors (to current version): |
3 |
|
* Mathias Preiner |
4 |
|
* |
5 |
|
* This file is part of the cvc5 project. |
6 |
|
* |
7 |
|
* Copyright (c) 2009-2021 by the authors listed in the file AUTHORS |
8 |
|
* in the top-level source directory and their institutional affiliations. |
9 |
|
* All rights reserved. See the file COPYING in the top-level source |
10 |
|
* directory for licensing information. |
11 |
|
* **************************************************************************** |
12 |
|
* |
13 |
|
* The BvIntroPow2 preprocessing pass. |
14 |
|
* |
15 |
|
* Traverses the formula and applies the IsPowerOfTwo rewrite rule. This |
16 |
|
* preprocessing pass is particularly useful on QF_BV/pspace benchmarks and |
17 |
|
* can be enabled via option `--bv-intro-pow2`. |
18 |
|
*/ |
19 |
|
|
20 |
|
#include "cvc5_private.h" |
21 |
|
|
22 |
|
#ifndef CVC5__PREPROCESSING__PASSES__BV_INTRO_POW2_H |
23 |
|
#define CVC5__PREPROCESSING__PASSES__BV_INTRO_POW2_H |
24 |
|
|
25 |
|
#include "preprocessing/preprocessing_pass.h" |
26 |
|
|
27 |
|
namespace cvc5 { |
28 |
|
namespace preprocessing { |
29 |
|
namespace passes { |
30 |
|
|
31 |
19878 |
class BvIntroPow2 : public PreprocessingPass |
32 |
|
{ |
33 |
|
public: |
34 |
|
BvIntroPow2(PreprocessingPassContext* preprocContext); |
35 |
|
|
36 |
|
protected: |
37 |
|
PreprocessingPassResult applyInternal( |
38 |
|
AssertionPipeline* assertionsToPreprocess) override; |
39 |
|
|
40 |
|
private: |
41 |
|
/** Checks whether PowerOfTwo rewrite applies. */ |
42 |
|
bool isPowerOfTwo(TNode node); |
43 |
|
/** |
44 |
|
* Applies PowerOfTwo rewrite. |
45 |
|
* |
46 |
|
* x & (x-1) = 0 => x = 1 << sk |
47 |
|
* |
48 |
|
* where sk is a fresh Skolem. |
49 |
|
* |
50 |
|
* WARNING: this is an **EQUISATISFIABLE** transformation! |
51 |
|
* Only to be called on top level assertions. |
52 |
|
*/ |
53 |
|
Node rewritePowerOfTwo(TNode node); |
54 |
|
/** Does the traversal of assertions and applies rweritePowerOfTwo. */ |
55 |
|
Node pow2Rewrite(Node node, std::unordered_map<Node, Node>& cache); |
56 |
|
}; |
57 |
|
|
58 |
|
} // namespace passes |
59 |
|
} // namespace preprocessing |
60 |
|
} // namespace cvc5 |
61 |
|
|
62 |
|
#endif /* CVC5__PREPROCESSING__PASSES__BV_INTRO_POW2_H */ |