Node CandidateGeneratorQEAll::getNextCandidate() {
while( !d_eq.isFinished() ){
TNode n = (*d_eq);
++d_eq;
if( n.getType().isSubtypeOf( d_match_pattern_type ) ){
TNode nh = d_qe->getTermDatabase()->getEligibleTermInEqc( n );
if( !nh.isNull() ){
if( options::instMaxLevel()!=-1 || options::lteRestrictInstClosure() ){
nh = d_qe->getEqualityQuery()->getInternalRepresentative( nh, d_f, d_index );
//don't consider this if already the instantiation is ineligible
if( !d_qe->getTermDatabase()->isTermEligibleForInstantiation( nh, d_f, false ) ){
nh = Node::null();
}
}
if( !nh.isNull() ){
d_firstTime = false;
//an equivalence class with the same type as the pattern, return it
return nh;
}
}
}
}
if( d_firstTime ){
Assert( d_qe->getTermDatabase()->d_type_map[d_match_pattern_type].empty() );
//must return something
d_firstTime = false;
return d_qe->getTermDatabase()->getModelBasisTerm( d_match_pattern_type );
}
return Node::null();
}
TNode EqualityQueryInstProp::getCongruentTerm( Node f, std::vector< TNode >& args ) {
TNode t = d_qe->getTermDatabase()->getCongruentTerm( f, args );
if( !t.isNull() ){
return t;
}else{
//TODO?
return TNode::null();
}
}
void AbsDef::construct_def_entry( FirstOrderModelAbs * m, TNode q, TNode n, int v, unsigned depth ) {
d_value = v;
if( depth<n.getNumChildren() ){
TypeNode tn = q.isNull() ? n[depth].getType() : m->getVariable( q, depth ).getType();
unsigned dom = m->d_domain[tn] ;
d_def[dom].construct_def_entry( m, q, n, v, depth+1 );
d_default = dom;
}
}
SatLiteral TheoryProxy::getNextTheoryDecisionRequest() {
TNode n = d_theoryEngine->getNextDecisionRequest();
return n.isNull() ? undefSatLiteral : d_cnfStream->getLiteral(n);
}
//this is identical to TermDb::evaluateTerm2, but tracks more information
Node EqualityQueryInstProp::evaluateTermExp( Node n, std::vector< Node >& exp, std::map< Node, Node >& visited, bool hasPol, bool pol,
std::map< Node, bool >& watch_list_out, std::vector< Node >& props ) {
std::map< Node, Node >::iterator itv = visited.find( n );
if( itv != visited.end() ){
return itv->second;
}else{
visited[n] = n;
Trace("qip-eval") << "evaluate term : " << n << std::endl;
std::vector< Node > exp_n;
Node ret = getRepresentativeExp( n, exp_n );
if( ret.isNull() ){
//term is not known to be equal to a representative in equality engine, evaluate it
Kind k = n.getKind();
if( k==FORALL ){
ret = Node::null();
}else{
std::map< Node, bool > watch_list_out_curr;
TNode f = d_qe->getTermDatabase()->getMatchOperator( n );
std::vector< Node > args;
bool ret_set = false;
bool childChanged = false;
int abort_i = -1;
//get the child entailed polarity
Assert( n.getKind()!=IMPLIES );
bool newHasPol, newPol;
QuantPhaseReq::getEntailPolarity( n, 0, hasPol, pol, newHasPol, newPol );
//for each child
for( unsigned i=0; i<n.getNumChildren(); i++ ){
Node c = evaluateTermExp( n[i], exp, visited, newHasPol, newPol, watch_list_out_curr, props );
if( c.isNull() ){
ret = Node::null();
ret_set = true;
break;
}else if( c==d_true || c==d_false ){
//short-circuiting
if( k==kind::AND || k==kind::OR ){
if( (k==kind::AND)==(c==d_false) ){
ret = c;
ret_set = true;
break;
}else{
//redundant
c = Node::null();
childChanged = true;
}
}else if( k==kind::ITE && i==0 ){
Assert( watch_list_out_curr.empty() );
ret = evaluateTermExp( n[ c==d_true ? 1 : 2], exp, visited, hasPol, pol, watch_list_out_curr, props );
ret_set = true;
break;
}else if( k==kind::NOT ){
ret = c==d_true ? d_false : d_true;
ret_set = true;
break;
}
}
if( !c.isNull() ){
childChanged = childChanged || n[i]!=c;
if( !f.isNull() && !watch_list_out_curr.empty() ){
// we are done if this is an UF application and an argument is unevaluated
args.push_back( c );
abort_i = i;
break;
}else if( ( k==kind::AND || k==kind::OR ) ){
if( c.getKind()==k ){
//flatten
for( unsigned j=0; j<c.getNumChildren(); j++ ){
addArgument( args, props, c[j], newHasPol, newPol );
}
}else{
addArgument( args, props, c, newHasPol, newPol );
}
//if we are in a branching position
if( hasPol && !newHasPol && args.size()>=2 ){
//we are done if at least two args are unevaluated
abort_i = i;
break;
}
}else if( k==kind::ITE ){
//we are done if we are ITE and condition is unevaluated
Assert( i==0 );
args.push_back( c );
abort_i = i;
break;
}else{
args.push_back( c );
}
}
}
//add remaining children if we aborted
if( abort_i!=-1 ){
for( int i=(abort_i+1); i<(int)n.getNumChildren(); i++ ){
args.push_back( n[i] );
}
}
//copy over the watch list
for( std::map< Node, bool >::iterator itc = watch_list_out_curr.begin(); itc != watch_list_out_curr.end(); ++itc ){
watch_list_out[itc->first] = itc->second;
}
//if we have not short-circuited evaluation
if( !ret_set ){
//if it is an indexed term, return the congruent term
if( !f.isNull() && watch_list_out.empty() ){
std::vector< TNode > t_args;
for( unsigned i=0; i<args.size(); i++ ) {
t_args.push_back( args[i] );
}
Assert( args.size()==n.getNumChildren() );
//args contains terms known by the equality engine
TNode nn = getCongruentTerm( f, t_args );
Trace("qip-eval") << " got congruent term " << nn << " from DB for " << n << std::endl;
if( !nn.isNull() ){
//successfully constructed representative in EE
Assert( exp_n.empty() );
ret = getRepresentativeExp( nn, exp_n );
Trace("qip-eval") << "return rep, exp size = " << exp_n.size() << std::endl;
merge_exp( exp, exp_n );
ret_set = true;
Assert( !ret.isNull() );
}
}
if( !ret_set ){
if( childChanged ){
Trace("qip-eval") << "return rewrite" << std::endl;
if( ( k==kind::AND || k==kind::OR ) ){
if( args.empty() ){
ret = k==kind::AND ? d_true : d_false;
ret_set = true;
}else if( args.size()==1 ){
ret = args[0];
ret_set = true;
}
}else{
Assert( args.size()==n.getNumChildren() );
}
if( !ret_set ){
if( n.getMetaKind() == kind::metakind::PARAMETERIZED ){
args.insert( args.begin(), n.getOperator() );
}
ret = NodeManager::currentNM()->mkNode( k, args );
ret = Rewriter::rewrite( ret );
//re-evaluate
Node ret_eval = getRepresentativeExp( ret, exp_n );
if( !ret_eval.isNull() ){
ret = ret_eval;
watch_list_out.clear();
}else{
watch_list_out[ret] = true;
}
}
}else{
ret = n;
watch_list_out[ret] = true;
}
}
}
}
}else{
Trace("qip-eval") << "...exists in ee, return rep, exp size = " << exp_n.size() << std::endl;
merge_exp( exp, exp_n );
}
Trace("qip-eval") << "evaluated term : " << n << ", got : " << ret << ", exp size = " << exp.size() << std::endl;
visited[n] = ret;
return ret;
}
}
void UnconstrainedSimplifier::processUnconstrained()
{
TNodeSet::iterator it = d_unconstrained.begin(), iend = d_unconstrained.end();
vector<TNode> workList;
for ( ; it != iend; ++it) {
workList.push_back(*it);
}
Node currentSub;
TNode parent;
bool swap;
bool isSigned;
bool strict;
vector<TNode> delayQueueLeft;
vector<Node> delayQueueRight;
TNode current = workList.back();
workList.pop_back();
for (;;) {
Assert(d_visitedOnce.find(current) != d_visitedOnce.end());
parent = d_visitedOnce[current];
if (!parent.isNull()) {
swap = isSigned = strict = false;
switch (parent.getKind()) {
// If-then-else operator - any two unconstrained children makes the parent unconstrained
case kind::ITE: {
Assert(parent[0] == current || parent[1] == current || parent[2] == current);
bool uCond = parent[0] == current || d_unconstrained.find(parent[0]) != d_unconstrained.end();
bool uThen = parent[1] == current || d_unconstrained.find(parent[1]) != d_unconstrained.end();
bool uElse = parent[2] == current || d_unconstrained.find(parent[2]) != d_unconstrained.end();
if ((uCond && uThen) || (uCond && uElse) || (uThen && uElse)) {
if (d_unconstrained.find(parent) == d_unconstrained.end() &&
!d_substitutions.hasSubstitution(parent)) {
++d_numUnconstrainedElim;
if (uThen) {
if (parent[1] != current) {
if (parent[1].isVar()) {
currentSub = parent[1];
}
else {
Assert(d_substitutions.hasSubstitution(parent[1]));
currentSub = d_substitutions.apply(parent[1]);
}
}
else if (currentSub.isNull()) {
currentSub = current;
}
}
else if (parent[2] != current) {
if (parent[2].isVar()) {
currentSub = parent[2];
}
else {
Assert(d_substitutions.hasSubstitution(parent[2]));
currentSub = d_substitutions.apply(parent[2]);
}
}
else if (currentSub.isNull()) {
currentSub = current;
}
current = parent;
}
else {
currentSub = Node();
}
}
else if (uCond) {
Cardinality card = parent.getType().getCardinality();
if (card.isFinite() && !card.isLargeFinite() && card.getFiniteCardinality() == 2) {
// Special case: condition is unconstrained, then and else are different, and total cardinality of the type is 2, then the result
// is unconstrained
Node test;
if (parent.getType().isBoolean()) {
test = Rewriter::rewrite(parent[1].iffNode(parent[2]));
}
else {
test = Rewriter::rewrite(parent[1].eqNode(parent[2]));
}
if (test == NodeManager::currentNM()->mkConst<bool>(false)) {
++d_numUnconstrainedElim;
if (currentSub.isNull()) {
currentSub = current;
}
currentSub = newUnconstrainedVar(parent.getType(), currentSub);
current = parent;
}
}
}
break;
}
// Comparisons that return a different type - assuming domains are larger than 1, any
// unconstrained child makes parent unconstrained as well
case kind::EQUAL:
if (parent[0].getType() != parent[1].getType()) {
TNode other = (parent[0] == current) ? parent[1] : parent[0];
if (current.getType().isSubtypeOf(other.getType())) {
break;
}
}
if( parent[0].getType().isDatatype() ){
TypeNode tn = parent[0].getType();
const Datatype& dt = ((DatatypeType)(tn).toType()).getDatatype();
if( dt.isRecursiveSingleton( tn.toType() ) ){
//domain size may be 1
break;
}
}
case kind::BITVECTOR_COMP:
case kind::LT:
case kind::LEQ:
case kind::GT:
case kind::GEQ:
{
if (d_unconstrained.find(parent) == d_unconstrained.end() &&
!d_substitutions.hasSubstitution(parent)) {
++d_numUnconstrainedElim;
Assert(parent[0] != parent[1] &&
(parent[0] == current || parent[1] == current));
if (currentSub.isNull()) {
currentSub = current;
}
currentSub = newUnconstrainedVar(parent.getType(), currentSub);
current = parent;
}
else {
currentSub = Node();
}
break;
}
// Unary operators that propagate unconstrainedness
case kind::NOT:
case kind::BITVECTOR_NOT:
case kind::BITVECTOR_NEG:
case kind::UMINUS:
++d_numUnconstrainedElim;
Assert(parent[0] == current);
if (currentSub.isNull()) {
currentSub = current;
}
current = parent;
break;
// Unary operators that propagate unconstrainedness and return a different type
case kind::BITVECTOR_EXTRACT:
++d_numUnconstrainedElim;
Assert(parent[0] == current);
if (currentSub.isNull()) {
currentSub = current;
}
currentSub = newUnconstrainedVar(parent.getType(), currentSub);
current = parent;
break;
// Operators returning same type requiring all children to be unconstrained
case kind::AND:
case kind::OR:
case kind::IMPLIES:
case kind::BITVECTOR_AND:
case kind::BITVECTOR_OR:
case kind::BITVECTOR_NAND:
case kind::BITVECTOR_NOR:
{
bool allUnconstrained = true;
for(TNode::iterator child_it = parent.begin(); child_it != parent.end(); ++child_it) {
if (d_unconstrained.find(*child_it) == d_unconstrained.end()) {
allUnconstrained = false;
break;
}
}
if (allUnconstrained) {
if (d_unconstrained.find(parent) == d_unconstrained.end() &&
!d_substitutions.hasSubstitution(parent)) {
++d_numUnconstrainedElim;
if (currentSub.isNull()) {
currentSub = current;
}
current = parent;
}
else {
currentSub = Node();
}
}
}
break;
// Require all children to be unconstrained and different
case kind::BITVECTOR_SHL:
case kind::BITVECTOR_LSHR:
case kind::BITVECTOR_ASHR:
case kind::BITVECTOR_UDIV_TOTAL:
case kind::BITVECTOR_UREM_TOTAL:
case kind::BITVECTOR_SDIV:
case kind::BITVECTOR_SREM:
case kind::BITVECTOR_SMOD: {
bool allUnconstrained = true;
bool allDifferent = true;
for(TNode::iterator child_it = parent.begin(); child_it != parent.end(); ++child_it) {
if (d_unconstrained.find(*child_it) == d_unconstrained.end()) {
allUnconstrained = false;
break;
}
for(TNode::iterator child_it2 = child_it + 1; child_it2 != parent.end(); ++child_it2) {
if (*child_it == *child_it2) {
allDifferent = false;
break;
}
}
}
if (allUnconstrained && allDifferent) {
if (d_unconstrained.find(parent) == d_unconstrained.end() &&
!d_substitutions.hasSubstitution(parent)) {
++d_numUnconstrainedElim;
if (currentSub.isNull()) {
currentSub = current;
}
current = parent;
}
else {
currentSub = Node();
}
}
break;
}
// Requires all children to be unconstrained and different, and returns a different type
case kind::BITVECTOR_CONCAT:
{
bool allUnconstrained = true;
bool allDifferent = true;
for(TNode::iterator child_it = parent.begin(); child_it != parent.end(); ++child_it) {
if (d_unconstrained.find(*child_it) == d_unconstrained.end()) {
allUnconstrained = false;
break;
}
for(TNode::iterator child_it2 = child_it + 1; child_it2 != parent.end(); ++child_it2) {
if (*child_it == *child_it2) {
allDifferent = false;
break;
}
}
}
if (allUnconstrained && allDifferent) {
if (d_unconstrained.find(parent) == d_unconstrained.end() &&
!d_substitutions.hasSubstitution(parent)) {
++d_numUnconstrainedElim;
if (currentSub.isNull()) {
currentSub = current;
}
currentSub = newUnconstrainedVar(parent.getType(), currentSub);
current = parent;
}
else {
currentSub = Node();
}
}
}
break;
// N-ary operators returning same type requiring at least one child to be unconstrained
case kind::PLUS:
case kind::MINUS:
if (current.getType().isInteger() &&
!parent.getType().isInteger()) {
break;
}
case kind::IFF:
case kind::XOR:
case kind::BITVECTOR_XOR:
case kind::BITVECTOR_XNOR:
case kind::BITVECTOR_PLUS:
case kind::BITVECTOR_SUB:
if (d_unconstrained.find(parent) == d_unconstrained.end() &&
!d_substitutions.hasSubstitution(parent)) {
++d_numUnconstrainedElim;
if (currentSub.isNull()) {
currentSub = current;
}
current = parent;
}
else {
currentSub = Node();
}
break;
// Multiplication/division: must be non-integer and other operand must be non-zero
case kind::MULT: {
case kind::DIVISION:
Assert(parent.getNumChildren() == 2);
TNode other;
if (parent[0] == current) {
other = parent[1];
}
else {
Assert(parent[1] == current);
other = parent[0];
}
if (d_unconstrained.find(other) != d_unconstrained.end()) {
if (d_unconstrained.find(parent) == d_unconstrained.end() &&
!d_substitutions.hasSubstitution(parent)) {
if (current.getType().isInteger() && other.getType().isInteger()) {
Assert(parent.getKind() == kind::DIVISION || parent.getType().isInteger());
if (parent.getKind() == kind::DIVISION) {
break;
}
}
++d_numUnconstrainedElim;
if (currentSub.isNull()) {
currentSub = current;
}
current = parent;
}
else {
currentSub = Node();
}
}
else {
// if only the denominator of a division is unconstrained, can't set it to 0 so the result is not unconstrained
if (parent.getKind() == kind::DIVISION && current == parent[1]) {
break;
}
NodeManager* nm = NodeManager::currentNM();
// if we are an integer, the only way we are unconstrained is if we are a MULT by -1
if (current.getType().isInteger()) {
// div/mult by 1 should have been simplified
Assert(other != nm->mkConst<Rational>(1));
if (other == nm->mkConst<Rational>(-1)) {
// div by -1 should have been simplified
Assert(parent.getKind() == kind::MULT);
Assert(parent.getType().isInteger());
}
else {
break;
}
}
else {
// TODO: could build ITE here
Node test = other.eqNode(nm->mkConst<Rational>(0));
if (Rewriter::rewrite(test) != nm->mkConst<bool>(false)) {
break;
}
}
++d_numUnconstrainedElim;
if (currentSub.isNull()) {
currentSub = current;
}
current = parent;
}
break;
}
// Bitvector MULT - current must only appear once in the children:
// all other children must be unconstrained or odd
case kind::BITVECTOR_MULT:
{
bool found = false;
bool done = false;
for(TNode::iterator child_it = parent.begin(); child_it != parent.end(); ++child_it) {
if ((*child_it) == current) {
if (found) {
done = true;
break;
}
found = true;
continue;
}
else if (d_unconstrained.find(*child_it) != d_unconstrained.end()) {
continue;
}
else {
NodeManager* nm = NodeManager::currentNM();
Node extractOp = nm->mkConst<BitVectorExtract>(BitVectorExtract(0,0));
vector<Node> children;
children.push_back(*child_it);
Node test = nm->mkNode(extractOp, children);
BitVector one(1,unsigned(1));
test = test.eqNode(nm->mkConst<BitVector>(one));
if (Rewriter::rewrite(test) != nm->mkConst<bool>(true)) {
done = true;
break;
}
}
}
if (done) {
break;
}
if (d_unconstrained.find(parent) == d_unconstrained.end() &&
!d_substitutions.hasSubstitution(parent)) {
++d_numUnconstrainedElim;
if (currentSub.isNull()) {
currentSub = current;
}
current = parent;
}
else {
currentSub = Node();
}
break;
}
// Uninterpreted function - if domain is infinite, no quantifiers are used, and any child is unconstrained, result is unconstrained
case kind::APPLY_UF:
if (d_logicInfo.isQuantified() || !current.getType().getCardinality().isInfinite()) {
break;
}
if (d_unconstrained.find(parent) == d_unconstrained.end() &&
!d_substitutions.hasSubstitution(parent)) {
++d_numUnconstrainedElim;
if (currentSub.isNull()) {
currentSub = current;
}
if (parent.getType() != current.getType()) {
currentSub = newUnconstrainedVar(parent.getType(), currentSub);
}
current = parent;
}
else {
currentSub = Node();
}
break;
// Array select - if array is unconstrained, so is result
case kind::SELECT:
if (parent[0] == current) {
++d_numUnconstrainedElim;
Assert(current.getType().isArray());
if (currentSub.isNull()) {
currentSub = current;
}
currentSub = newUnconstrainedVar(current.getType().getArrayConstituentType(), currentSub);
current = parent;
}
break;
// Array store - if both store and value are unconstrained, so is resulting store
case kind::STORE:
if (((parent[0] == current &&
d_unconstrained.find(parent[2]) != d_unconstrained.end()) ||
(parent[2] == current &&
d_unconstrained.find(parent[0]) != d_unconstrained.end()))) {
if (d_unconstrained.find(parent) == d_unconstrained.end() &&
!d_substitutions.hasSubstitution(parent)) {
++d_numUnconstrainedElim;
if (parent[0] != current) {
if (parent[0].isVar()) {
currentSub = parent[0];
}
else {
Assert(d_substitutions.hasSubstitution(parent[0]));
currentSub = d_substitutions.apply(parent[0]);
}
}
else if (currentSub.isNull()) {
currentSub = current;
}
current = parent;
}
else {
currentSub = Node();
}
}
break;
// Bit-vector comparisons: replace with new Boolean variable, but have
// to also conjoin with a side condition as there is always one case
// when the comparison is forced to be false
case kind::BITVECTOR_ULT:
case kind::BITVECTOR_UGE:
case kind::BITVECTOR_UGT:
case kind::BITVECTOR_ULE:
case kind::BITVECTOR_SLT:
case kind::BITVECTOR_SGE:
case kind::BITVECTOR_SGT:
case kind::BITVECTOR_SLE: {
// Tuples over (signed, swap, strict).
switch (parent.getKind()) {
case kind::BITVECTOR_UGE:
break;
case kind::BITVECTOR_ULT:
strict = true;
break;
case kind::BITVECTOR_ULE:
swap = true;
break;
case kind::BITVECTOR_UGT:
swap = true;
strict = true;
break;
case kind::BITVECTOR_SGE:
isSigned = true;
break;
case kind::BITVECTOR_SLT:
isSigned = true;
strict = true;
break;
case kind::BITVECTOR_SLE:
isSigned = true;
swap = true;
break;
case kind::BITVECTOR_SGT:
isSigned = true;
swap = true;
strict = true;
break;
default:
Unreachable();
}
TNode other;
bool left = false;
if (parent[0] == current) {
other = parent[1];
left = true;
} else {
Assert(parent[1] == current);
other = parent[0];
}
if (d_unconstrained.find(other) != d_unconstrained.end()) {
if (d_unconstrained.find(parent) == d_unconstrained.end() &&
!d_substitutions.hasSubstitution(parent)) {
++d_numUnconstrainedElim;
if (currentSub.isNull()) {
currentSub = current;
}
currentSub = newUnconstrainedVar(parent.getType(), currentSub);
current = parent;
} else {
currentSub = Node();
}
} else {
unsigned size = current.getType().getBitVectorSize();
BitVector bv =
isSigned ? BitVector(size, Integer(1).multiplyByPow2(size - 1))
: BitVector(size, unsigned(0));
if (swap == left) {
bv = ~bv;
}
if (currentSub.isNull()) {
currentSub = current;
}
currentSub = newUnconstrainedVar(parent.getType(), currentSub);
current = parent;
NodeManager* nm = NodeManager::currentNM();
Node test =
Rewriter::rewrite(other.eqNode(nm->mkConst<BitVector>(bv)));
if (test == nm->mkConst<bool>(false)) {
break;
}
if (strict) {
currentSub = currentSub.andNode(test.notNode());
} else {
currentSub = currentSub.orNode(test);
}
// Delay adding this substitution - see comment at end of function
delayQueueLeft.push_back(current);
delayQueueRight.push_back(currentSub);
currentSub = Node();
parent = TNode();
}
break;
}
// Do nothing
case kind::BITVECTOR_SIGN_EXTEND:
case kind::BITVECTOR_ZERO_EXTEND:
case kind::BITVECTOR_REPEAT:
case kind::BITVECTOR_ROTATE_LEFT:
case kind::BITVECTOR_ROTATE_RIGHT:
default:
break;
}
if (current == parent && d_visited[parent] == 1) {
d_unconstrained.insert(parent);
continue;
}
}
if (!currentSub.isNull()) {
Assert(currentSub.isVar());
d_substitutions.addSubstitution(current, currentSub, false);
}
if (workList.empty()) {
break;
}
current = workList.back();
currentSub = Node();
workList.pop_back();
}
TNode left;
Node right;
// All substitutions except those arising from bitvector comparisons are
// substitutions t -> x where x is a variable. This allows us to build the
// substitution very quickly (never invalidating the substitution cache).
// Bitvector comparisons are more complicated and may require
// back-substitution and cache-invalidation. So we do these last.
while (!delayQueueLeft.empty()) {
left = delayQueueLeft.back();
if (!d_substitutions.hasSubstitution(left)) {
right = d_substitutions.apply(delayQueueRight.back());
d_substitutions.addSubstitution(delayQueueLeft.back(), right);
}
delayQueueLeft.pop_back();
delayQueueRight.pop_back();
}
}
