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/********************* */
/*! \file shared_term_manager.cpp
** \verbatim
** Original author: barrett
** Major contributors: none
** Minor contributors (to current version): none
** This file is part of the CVC4 prototype.
** Copyright (c) 2009, 2010 The Analysis of Computer Systems Group (ACSys)
** Courant Institute of Mathematical Sciences
** New York University
** See the file COPYING in the top-level source directory for licensing
** information.\endverbatim
**
** \brief The shared term manager
**
** The shared term manager
**/
#include "theory/theory_engine.h"
using namespace std;
using namespace CVC4;
using namespace CVC4::theory;
namespace CVC4 {
SharedTermManager::SharedTermManager(TheoryEngine* engine,
context::Context* context)
: d_engine(engine), d_context(context), d_theories(64) {
}
SharedData* SharedTermManager::find(SharedData* pData) {
SharedData* next = pData->getFind();
if (next == pData) return pData;
SharedData* nextNext = next->getFind();
if (nextNext == next) return next;
next = find(nextNext);
pData->setFind(next);
return next;
}
void SharedTermManager::registerTheory(Theory* th) {
Assert(th->getId() < 64, "Theory ID out of bounds");
d_theories[th->getId()] = th;
}
void SharedTermManager::addTerm(TNode n, Theory* parent, Theory* child) {
Assert(parent->getId() < 64 && child->getId() < 64,
"Theory ID out of bounds");
Assert(d_theories[parent->getId()] == parent &&
d_theories[child->getId()] == child,
"Theory not registered");
// A theory tag is represented by a 1 in the i^th bit where i is the
// theory id
uint64_t parentTag = (1 << parent->getId());
uint64_t childTag = (1 << child->getId());
uint64_t newTags = parentTag | childTag;
SharedData* pData;
if(n.getAttribute(SharedAttr(), pData)) {
// The attribute already exists, just update it if necessary
uint64_t tags = pData->getTheories();
newTags |= tags;
if (tags == newTags) return;
if (!(tags & parentTag)) {
parent->addSharedTerm(n);
}
if (!(tags & childTag)) {
child->addSharedTerm(n);
}
pData->setTheories(newTags);
} else {
// The attribute does not exist, so it is created and set
pData = new (true) SharedData(d_context, n, newTags);
n.setAttribute(SharedAttr(), pData);
parent->addSharedTerm(n);
child->addSharedTerm(n);
}
}
void SharedTermManager::addEq(Theory* thReason, TNode eq) {
Assert(eq.getKind() == kind::EQUAL &&
eq[0].hasAttribute(SharedAttr()) && eq[1].hasAttribute(SharedAttr()),
"SharedTermManager::addEq precondition violated");
TNode x = eq[0];
TNode y = eq[1];
SharedData* pDataX = x.getAttribute(SharedAttr());
SharedData* pDataY = y.getAttribute(SharedAttr());
SharedData* pDataXX = find(pDataX);
SharedData* pDataYY = find(pDataY);
if(pDataXX == pDataYY) return;
if(pDataXX->getSize() > pDataYY->getSize()) {
SharedData* tmp = pDataXX;
pDataXX = pDataYY;
pDataYY = tmp;
tmp = pDataX;
pDataX = pDataY;
pDataY = tmp;
}
pDataX->reverseEdges();
pDataX->setEquality(eq);
pDataX->setExplainingTheory(thReason);
pDataX->setProofNext(pDataY);
pDataXX->setFind(pDataYY);
pDataYY->setSize(pDataYY->getSize() + pDataXX->getSize());
uint64_t tags = pDataXX->getTheories();
pDataYY->setTheories(pDataYY->getTheories() | tags);
int id = 0;
while (tags != 0) {
if (tags & 1) {
d_theories[id]->notifyEq(pDataXX->getRep(), pDataYY->getRep());
}
tags = tags >> 1;
++id;
}
}
// Explain this equality
Node SharedTermManager::explain(TNode eq) {
Assert(eq.getKind() == kind::EQUAL &&
eq[0].hasAttribute(SharedAttr()) && eq[1].hasAttribute(SharedAttr()),
"SharedTermManager::explain precondition violated");
TNode x = eq[0];
TNode y = eq[1];
SharedData* pDataX = x.getAttribute(SharedAttr());
SharedData* pDataY = y.getAttribute(SharedAttr());
Assert(find(pDataX) == find(pDataY),
"invalid equality input to SharedTermManager::explain");
std::set<Node> s;
Node n;
SharedData* tmp = pDataX;
// Check to see if Y is on path from X to root
while (!tmp->isProofRoot() && tmp != pDataY) {
tmp = tmp->getProofNext();
}
if (tmp == pDataY) {
// Y is on path from X to root, just traverse that path
while (pDataX != pDataY) {
n = d_engine->getExplanation(pDataX->getEquality(),
pDataX->getExplainingTheory());
for (Node::iterator it = n.begin(), iend = n.end(); it != iend; ++it) {
s.insert(*it);
}
pDataX = pDataX->getProofNext();
}
}
else {
// Y is not on path from X to root, so traverse from Y to root instead
while (!pDataY->isProofRoot() && pDataX != pDataY) {
n = d_engine->getExplanation(pDataY->getEquality(),
pDataY->getExplainingTheory());
for (Node::iterator it = n.begin(), iend = n.end(); it != iend; ++it) {
s.insert(*it);
}
pDataY = pDataY->getProofNext();
}
}
if (pDataX != pDataY) {
// X and Y are on different branches - have to traverse both
while (!pDataX->isProofRoot()) {
n = d_engine->getExplanation(pDataX->getEquality(),
pDataX->getExplainingTheory());
for (Node::iterator it = n.begin(), iend = n.end(); it != iend; ++it) {
s.insert(*it);
}
pDataX = pDataX->getProofNext();
}
}
// Build explanation from s
NodeBuilder<kind::AND> nb;
set<Node>::iterator it = s.begin(), iend = s.end();
for (; it != iend; ++it) {
nb << *it;
}
return nb.constructNode();
}
}/* CVC4 namespace */
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