Head

GCC Code Coverage Report

Directory:	.		Exec	Total	Coverage
File:	src/preprocessing/passes/bv_gauss.h	Lines:	1	1	100.0 %
Date:	2021-08-01	Branches:	0	0	0.0 %


/******************************************************************************
 * Top contributors (to current version):
 *   Aina Niemetz, Mathias Preiner, Andres Noetzli
 *
 * This file is part of the cvc5 project.
 *
 * Copyright (c) 2009-2021 by the authors listed in the file AUTHORS
 * in the top-level source directory and their institutional affiliations.
 * All rights reserved.  See the file COPYING in the top-level source
 * directory for licensing information.
 * ****************************************************************************
 *
 * Gaussian Elimination preprocessing pass.
 *
 * Simplify a given equation system modulo a (prime) number via Gaussian
 * Elimination if possible.
 */

#include "cvc5_private.h"

#ifndef CVC5__PREPROCESSING__PASSES__BV_GAUSS_ELIM_H
#define CVC5__PREPROCESSING__PASSES__BV_GAUSS_ELIM_H

#include "expr/node.h"
#include "preprocessing/preprocessing_pass.h"
#include "util/integer.h"

namespace cvc5 {
namespace preprocessing {
namespace passes {

class BVGauss : public PreprocessingPass
{
 public:
  BVGauss(PreprocessingPassContext* preprocContext,
          const std::string& name = "bv-gauss");

 protected:
  /**
   * Apply Gaussian Elimination on (possibly multiple) set(s) of equations
   * modulo some (prime) number given as bit-vector equations.
   *
   * Note that these sets of equations do not have to be modulo some prime
   * but can be modulo any arbitrary number. However, GE is guaranteed to
   * succeed modulo a prime number, which is not necessarily the case if a
   * given set of equations is modulo a non-prime number.
   */
  PreprocessingPassResult applyInternal(
      AssertionPipeline* assertionsToPreprocess) override;

 private:
  /* Note: The following functionality is only exposed for unit testing in
   * pass_bv_gauss_white.h. */

  /**
   *  Represents the result of Gaussian Elimination where the solution
   *  of the given equation system is
   *
   *   INVALID ... i.e., NOT of the form c1*x1 + c2*x2 + ... % p = b,
   *               where ci, b and p are
   *                 - bit-vector constants
   *                 - extracts or zero extensions on bit-vector constants
   *                 - of arbitrary nesting level
   *               and p is co-prime to all bit-vector constants for which
   *               a multiplicative inverse has to be computed.
   *
   *   UNIQUE  ... determined for all unknowns, e.g., x = 4
   *
   *   PARTIAL ... e.g., x = 4 - 2z
   *
   *   NONE    ... no solution
   *
   *   Given a matrix A representing an equation system, the resulting
   *   matrix B after applying GE represents, e.g.:
   *
   *   B = 1 0 0 2 <-    UNIQUE
   *       0 1 0 3 <-
   *       0 0 1 1 <-
   *
   *   B = 1 0 2 4 <-    PARTIAL
   *       0 1 3 2 <-
   *       0 0 1 1
   *
   *   B = 1 0 0 1       NONE
   *       0 1 1 2
   *       0 0 0 2 <-
   */
  enum class Result
  {
    INVALID,
    UNIQUE,
    PARTIAL,
    NONE
  };

  static Result gaussElim(Integer prime,
                          std::vector<Integer>& rhs,
                          std::vector<std::vector<Integer>>& lhs);

  static Result gaussElimRewriteForUrem(const std::vector<Node>& equations,
                                        std::unordered_map<Node, Node>& res);

  static unsigned getMinBwExpr(Node expr);
};

}  // namespace passes
}  // namespace preprocessing
}  // namespace cvc5

#endif


Generated by: GCOVR (Version 3.2)

Line	Exec	Source
1		/******************************************************************************
2		* Top contributors (to current version):
3		* Aina Niemetz, Mathias Preiner, Andres Noetzli
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		* Gaussian Elimination preprocessing pass.
14		*
15		* Simplify a given equation system modulo a (prime) number via Gaussian
16		* Elimination if possible.
17		*/
18
19		#include "cvc5_private.h"
20
21		#ifndef CVC5__PREPROCESSING__PASSES__BV_GAUSS_ELIM_H
22		#define CVC5__PREPROCESSING__PASSES__BV_GAUSS_ELIM_H
23
24		#include "expr/node.h"
25		#include "preprocessing/preprocessing_pass.h"
26		#include "util/integer.h"
27
28		namespace cvc5 {
29		namespace preprocessing {
30		namespace passes {
31
32	19682	class BVGauss : public PreprocessingPass
33		{
34		public:
35		BVGauss(PreprocessingPassContext* preprocContext,
36		const std::string& name = "bv-gauss");
37
38		protected:
39		/**
40		* Apply Gaussian Elimination on (possibly multiple) set(s) of equations
41		* modulo some (prime) number given as bit-vector equations.
42		*
43		* Note that these sets of equations do not have to be modulo some prime
44		* but can be modulo any arbitrary number. However, GE is guaranteed to
45		* succeed modulo a prime number, which is not necessarily the case if a
46		* given set of equations is modulo a non-prime number.
47		*/
48		PreprocessingPassResult applyInternal(
49		AssertionPipeline* assertionsToPreprocess) override;
50
51		private:
52		/* Note: The following functionality is only exposed for unit testing in
53		* pass_bv_gauss_white.h. */
54
55		/**
56		* Represents the result of Gaussian Elimination where the solution
57		* of the given equation system is
58		*
59		* INVALID ... i.e., NOT of the form c1x1 + c2x2 + ... % p = b,
60		* where ci, b and p are
61		* - bit-vector constants
62		* - extracts or zero extensions on bit-vector constants
63		* - of arbitrary nesting level
64		* and p is co-prime to all bit-vector constants for which
65		* a multiplicative inverse has to be computed.
66		*
67		* UNIQUE ... determined for all unknowns, e.g., x = 4
68		*
69		* PARTIAL ... e.g., x = 4 - 2z
70		*
71		* NONE ... no solution
72		*
73		* Given a matrix A representing an equation system, the resulting
74		* matrix B after applying GE represents, e.g.:
75		*
76		* B = 1 0 0 2 <- UNIQUE
77		* 0 1 0 3 <-
78		* 0 0 1 1 <-
79		*
80		* B = 1 0 2 4 <- PARTIAL
81		* 0 1 3 2 <-
82		* 0 0 1 1
83		*
84		* B = 1 0 0 1 NONE
85		* 0 1 1 2
86		* 0 0 0 2 <-
87		*/
88		enum class Result
89		{
90		INVALID,
91		UNIQUE,
92		PARTIAL,
93		NONE
94		};
95
96		static Result gaussElim(Integer prime,
97		std::vector<Integer>& rhs,
98		std::vector<std::vector<Integer>>& lhs);
99
100		static Result gaussElimRewriteForUrem(const std::vector<Node>& equations,
101		std::unordered_map<Node, Node>& res);
102
103		static unsigned getMinBwExpr(Node expr);
104		};
105
106		} // namespace passes
107		} // namespace preprocessing
108		} // namespace cvc5
109
110		#endif