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/******************************************************************************
* Top contributors (to current version):
* Mathias Preiner
*
* 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.
* ****************************************************************************
*
* Bitblaster used to bitblast to Boolean Nodes.
*/
#include "theory/bv/bitblast/node_bitblaster.h"
#include "options/bv_options.h"
#include "theory/theory_model.h"
#include "theory/theory_state.h"
namespace cvc5 {
namespace theory {
namespace bv {
NodeBitblaster::NodeBitblaster(TheoryState* s) : TBitblaster<Node>(), d_state(s)
{
}
void NodeBitblaster::bbAtom(TNode node)
{
node = node.getKind() == kind::NOT ? node[0] : node;
if (hasBBAtom(node))
{
return;
}
Node normalized = Rewriter::rewrite(node);
Node atom_bb =
normalized.getKind() != kind::CONST_BOOLEAN
&& normalized.getKind() != kind::BITVECTOR_BITOF
? d_atomBBStrategies[normalized.getKind()](normalized, this)
: normalized;
storeBBAtom(node, Rewriter::rewrite(atom_bb));
}
void NodeBitblaster::storeBBAtom(TNode atom, Node atom_bb)
{
d_bbAtoms.emplace(atom, atom_bb);
}
void NodeBitblaster::storeBBTerm(TNode node, const Bits& bits)
{
d_termCache.emplace(node, bits);
}
bool NodeBitblaster::hasBBAtom(TNode lit) const
{
if (lit.getKind() == kind::NOT)
{
lit = lit[0];
}
return d_bbAtoms.find(lit) != d_bbAtoms.end();
}
void NodeBitblaster::makeVariable(TNode var, Bits& bits)
{
Assert(bits.size() == 0);
for (unsigned i = 0; i < utils::getSize(var); ++i)
{
bits.push_back(utils::mkBitOf(var, i));
}
d_variables.insert(var);
}
Node NodeBitblaster::getBBAtom(TNode node) const { return node; }
void NodeBitblaster::bbTerm(TNode node, Bits& bits)
{
Assert(node.getType().isBitVector());
if (hasBBTerm(node))
{
getBBTerm(node, bits);
return;
}
d_termBBStrategies[node.getKind()](node, bits, this);
Assert(bits.size() == utils::getSize(node));
storeBBTerm(node, bits);
}
Node NodeBitblaster::getStoredBBAtom(TNode node)
{
bool negated = false;
if (node.getKind() == kind::NOT)
{
node = node[0];
negated = true;
}
Assert(hasBBAtom(node));
Node atom_bb = d_bbAtoms.at(node);
return negated ? atom_bb.negate() : atom_bb;
}
Node NodeBitblaster::getModelFromSatSolver(TNode a, bool fullModel)
{
if (!hasBBTerm(a))
{
return utils::mkConst(utils::getSize(a), 0u);
}
bool assignment;
Bits bits;
getBBTerm(a, bits);
Integer value(0);
Integer one(1), zero(0);
for (int i = bits.size() - 1; i >= 0; --i)
{
Integer bit;
if (d_state->hasSatValue(bits[i], assignment))
{
bit = assignment ? one : zero;
}
else
{
bit = zero;
}
value = value * 2 + bit;
}
return utils::mkConst(bits.size(), value);
}
void NodeBitblaster::computeRelevantTerms(std::set<Node>& termSet)
{
Assert(options::bitblastMode() == options::BitblastMode::EAGER);
for (const auto& var : d_variables)
{
termSet.insert(var);
}
}
bool NodeBitblaster::collectModelValues(TheoryModel* m,
const std::set<Node>& relevantTerms)
{
for (const auto& var : relevantTerms)
{
if (d_variables.find(var) == d_variables.end()) continue;
Node const_value = getModelFromSatSolver(var, true);
Assert(const_value.isNull() || const_value.isConst());
if (!const_value.isNull())
{
if (!m->assertEquality(var, const_value, true))
{
return false;
}
}
}
return true;
}
bool NodeBitblaster::isVariable(TNode node)
{
return d_variables.find(node) != d_variables.end();
}
} // namespace bv
} // namespace theory
} // namespace cvc5
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