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/****************************************************************************** |
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* Top contributors (to current version): |
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* Aina Niemetz, Andrew Reynolds, Tim King |
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* |
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* This file is part of the cvc5 project. |
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* |
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* Copyright (c) 2009-2021 by the authors listed in the file AUTHORS |
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* in the top-level source directory and their institutional affiliations. |
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* All rights reserved. See the file COPYING in the top-level source |
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* directory for licensing information. |
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* **************************************************************************** |
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* |
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* Util functions for theory BV. |
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*/ |
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#include "cvc5_private.h" |
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#pragma once |
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#include <set> |
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#include <unordered_map> |
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#include <unordered_set> |
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#include <vector> |
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#include "expr/node_manager.h" |
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#include "util/integer.h" |
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namespace cvc5 { |
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namespace theory { |
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namespace bv { |
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typedef std::unordered_set<Node> NodeSet; |
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typedef std::unordered_set<TNode> TNodeSet; |
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namespace utils { |
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typedef std::unordered_map<TNode, bool> TNodeBoolMap; |
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typedef std::unordered_set<Node> NodeSet; |
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/* Get the bit-width of given node. */ |
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unsigned getSize(TNode node); |
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/* Get bit at given index. */ |
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const bool getBit(TNode node, unsigned i); |
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/* Get the upper index of given extract node. */ |
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unsigned getExtractHigh(TNode node); |
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/* Get the lower index of given extract node. */ |
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unsigned getExtractLow(TNode node); |
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/* Get the number of bits by which a given node is extended. */ |
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unsigned getSignExtendAmount(TNode node); |
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/* Returns true if given node represents a bit-vector comprised of ones. */ |
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bool isOnes(TNode node); |
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/* Returns true if given node represents a zero bit-vector. */ |
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bool isZero(TNode node); |
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/* Returns true if given node represents a one bit-vector. */ |
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bool isOne(TNode node); |
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/* If node is a constant of the form 2^c or -2^c, then this function returns |
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* c+1. Otherwise, this function returns 0. The flag isNeg is updated to |
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* indicate whether node is negative. */ |
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unsigned isPow2Const(TNode node, bool& isNeg); |
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/* Returns true if node or all of its children is const. */ |
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bool isBvConstTerm(TNode node); |
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/* Returns true if node is a predicate over bit-vector nodes. */ |
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bool isBVPredicate(TNode node); |
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/* Returns true if given term is |
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* - not a THEORY_BV term |
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* - a THEORY_BV \Sigma_core term, where |
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* \Sigma_core = { concat, extract, =, bv constants, bv variables } */ |
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bool isCoreTerm(TNode term, TNodeBoolMap& cache); |
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/* Returns true if given term is a THEORY_BV \Sigma_equality term. |
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* \Sigma_equality = { =, bv constants, bv variables } */ |
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bool isEqualityTerm(TNode term, TNodeBoolMap& cache); |
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/* Returns true if given node is an atom that is bit-blasted. */ |
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bool isBitblastAtom(Node lit); |
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/* Create Boolean node representing true. */ |
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Node mkTrue(); |
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/* Create Boolean node representing false. */ |
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Node mkFalse(); |
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/* Create bit-vector node representing a bit-vector of ones of given size. */ |
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Node mkOnes(unsigned size); |
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/* Create bit-vector node representing a zero bit-vector of given size. */ |
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Node mkZero(unsigned size); |
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/* Create bit-vector node representing a bit-vector value one of given size. */ |
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Node mkOne(unsigned size); |
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/* Create bit-vector node representing the min signed value of given size. */ |
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Node mkMinSigned(unsigned size); |
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/* Create bit-vector node representing the max signed value of given size. */ |
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Node mkMaxSigned(unsigned size); |
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/* Create bit-vector constant of given size and value. */ |
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Node mkConst(unsigned size, unsigned int value); |
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Node mkConst(unsigned size, Integer& value); |
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/* Create bit-vector constant from given bit-vector. */ |
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Node mkConst(const BitVector& value); |
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/* Create bit-vector variable. */ |
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Node mkVar(unsigned size); |
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/* Create n-ary bit-vector node of kind BITVECTOR_AND, BITVECTOR_OR or |
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* BITVECTOR_XOR where its children are sorted */ |
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Node mkSortedNode(Kind kind, TNode child1, TNode child2); |
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Node mkSortedNode(Kind kind, std::vector<Node>& children); |
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/* Create n-ary node of associative/commutative kind. */ |
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template<bool ref_count> |
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Node mkNaryNode(Kind k, const std::vector<NodeTemplate<ref_count>>& nodes) |
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{ |
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Assert(k == kind::AND || k == kind::OR || k == kind::XOR |
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|| k == kind::BITVECTOR_AND || k == kind::BITVECTOR_OR |
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|| k == kind::BITVECTOR_XOR || k == kind::BITVECTOR_ADD |
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|| k == kind::BITVECTOR_SUB || k == kind::BITVECTOR_MULT); |
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if (nodes.size() == 1) { return nodes[0]; } |
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return NodeManager::currentNM()->mkNode(k, nodes); |
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} |
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/* Create node of kind NOT. */ |
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Node mkNot(Node child); |
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/* Create node of kind AND. */ |
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Node mkAnd(TNode node1, TNode node2); |
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/* Create n-ary node of kind AND. */ |
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template<bool ref_count> |
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Node mkAnd(const std::vector<NodeTemplate<ref_count>>& conjunctions) |
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{ |
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std::set<TNode> all(conjunctions.begin(), conjunctions.end()); |
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Assert(all.size() > 0); |
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/* All the same, or just one */ |
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if (all.size() == 1) { return conjunctions[0]; } |
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NodeBuilder conjunction(kind::AND); |
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for (TNode n : all) { conjunction << n; } |
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return conjunction; |
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} |
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/* ------------------------------------------------------------------------- */ |
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/* Create node of kind OR. */ |
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Node mkOr(TNode node1, TNode node2); |
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/* Create n-ary node of kind OR. */ |
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template<bool ref_count> |
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Node mkOr(const std::vector<NodeTemplate<ref_count>>& nodes) |
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{ |
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std::set<TNode> all(nodes.begin(), nodes.end()); |
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Assert(all.size() > 0); |
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/* All the same, or just one */ |
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if (all.size() == 1) { return nodes[0]; } |
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NodeBuilder disjunction(kind::OR); |
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for (TNode n : all) { disjunction << n; } |
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return disjunction; |
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} |
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/* Create node of kind XOR. */ |
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Node mkXor(TNode node1, TNode node2); |
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/* Create signed extension node where given node is extended by given amount. */ |
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Node mkSignExtend(TNode node, unsigned amount); |
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/* Create extract node where bits from index high to index low are extracted |
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* from given node. */ |
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Node mkExtract(TNode node, unsigned high, unsigned low); |
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/* Create extract node of bit-width 1 where the resulting node represents |
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* the bit at given index. */ |
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Node mkBitOf(TNode node, unsigned index); |
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/* Create n-ary concat node of given children. */ |
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Node mkConcat(TNode t1, TNode t2); |
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Node mkConcat(std::vector<Node>& children); |
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/* Create concat by repeating given node n times. |
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* Returns given node if n = 1. */ |
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Node mkConcat(TNode node, unsigned repeat); |
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/* Create bit-vector addition node representing the increment of given node. */ |
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Node mkInc(TNode t); |
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/* Create bit-vector addition node representing the decrement of given node. */ |
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Node mkDec(TNode t); |
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/* Unsigned multiplication overflow detection. |
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* See M.Gok, M.J. Schulte, P.I. Balzola, "Efficient integer multiplication |
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* overflow detection circuits", 2001. |
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* http://ieeexplore.ieee.org/document/987767 */ |
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Node mkUmulo(TNode t1, TNode t2); |
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/* Create conjunction. */ |
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Node mkConjunction(const std::vector<TNode>& nodes); |
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/* Create a flattened and node. */ |
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Node flattenAnd(std::vector<TNode>& queue); |
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/* Create the intersection of two vectors of uint32_t. */ |
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void intersect(const std::vector<uint32_t>& v1, |
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const std::vector<uint32_t>& v2, |
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std::vector<uint32_t>& intersection); |
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/** |
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* Returns the rewritten form of node, which is a term of the form bv2nat(x). |
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* The return value of this method is the integer sum: |
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* (+ ite( (= ((_ extract (n-1) (n-1)) x) 1) (^ 2 (n-1)) 0) |
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* ... |
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* ite( (= ((_ extract 0 0) x) 1) (^ 2 0) 0)) |
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* where n is the bitwidth of x. |
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*/ |
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Node eliminateBv2Nat(TNode node); |
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/** |
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* Returns the rewritten form of node, which is a term of the form int2bv(x). |
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* The return value of this method is the concatenation term: |
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* (bvconcat ite( (>= (mod x (^ 2 n)) (^ 2 (n-1))) (_ bv1 1) (_ bv1 0)) |
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* ... |
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* ite( (>= (mod x (^ 2 1)) (^ 2 0)) (_ bv1 1) (_ bv1 0))) |
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* where n is the bit-width of x. |
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*/ |
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Node eliminateInt2Bv(TNode node); |
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} |
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} |
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} |
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} // namespace cvc5 |