// If the bits are totally fixed, then return a new matching ASTNode.
ASTNode
bitsToNode(const ASTNode& node, const FixedBits& bits)
{
ASTNode result;
STPMgr & beev = *node.GetSTPMgr();
assert (bits.isTotallyFixed());
assert (!node.isConstant()); // Peformance. Shouldn't waste time calling it on constants.
if (node.GetType() == BOOLEAN_TYPE)
{
if (bits.getValue(0))
{
result = beev.CreateNode(TRUE);
}
else
{
result = beev.CreateNode(FALSE);
}
}
else if (node.GetType() == BITVECTOR_TYPE)
{
result = beev.CreateBVConst(bits.GetBVConst(), node.GetValueWidth());
}
else
FatalError("sadf234s");
assert(result.isConstant());
return result;
}
// Build the polarities, then iterate through fixing them.
bool FindPureLiterals::topLevel(ASTNode& n, Simplifier* simplifier,
STPMgr* stpMgr)
{
stpMgr->GetRunTimes()->start(RunTimes::PureLiterals);
build(n, truePolarity);
bool changed = false;
map<ASTNode, polarity_type>::const_iterator it = nodeToPolarity.begin();
while (it != nodeToPolarity.end())
{
const ASTNode& n = it->first;
const polarity_type polarity = it->second;
if (n.GetType() == BOOLEAN_TYPE && n.GetKind() == SYMBOL &&
polarity != bothPolarity)
{
if (polarity == truePolarity)
simplifier->UpdateSubstitutionMap(n, stpMgr->ASTTrue);
else
{
assert(polarity == falsePolarity);
simplifier->UpdateSubstitutionMap(n, stpMgr->ASTFalse);
}
changed = true;
}
it++;
}
stpMgr->GetRunTimes()->stop(RunTimes::PureLiterals);
return changed;
}
bool containsArrayOps(const ASTNode& n, ASTNodeSet& visited)
{
if (visited.find(n) != visited.end())
return false;
if (n.GetType() == ARRAY_TYPE)
return true;
for (int i =0; i < n.Degree();i++)
if (containsArrayOps(n[i],visited))
return true;
visited.insert(n);
return false;
}
// Propagates. No writing in of values. Doesn't assume the top is true.
ConstantBitPropagation::ConstantBitPropagation(BEEV::Simplifier* _sm, NodeFactory* _nf,const ASTNode & top)
{
assert (BOOLEAN_TYPE == top.GetType());
assert (top.GetSTPMgr()->UserFlags.bitConstantProp_flag);
status = NO_CHANGE;
simplifier = _sm;
nf = _nf;
fixedMap = new NodeToFixedBitsMap(1000); // better to use the function that returns the number of nodes.. whatever that is.
workList = new WorkList(top);
dependents = new Dependencies(top); // List of the parents of a node.
msm = new MultiplicationStatsMap();
// not fixing the topnode.
propagate();
if (debug_cBitProp_messages)
{
cerr << "status:" << status <<endl;
cerr << "ended propagation" << endl;
printNodeWithFixings();
}
// is there are good reason to clear out some of them??
#if 0
// remove constants, and things with nothing fixed.
NodeToFixedBitsMap::NodeToFixedBitsMapType::iterator it =
fixedMap->map->begin();
NodeToFixedBitsMap::NodeToFixedBitsMapType::iterator it_end =
fixedMap->map->end();
while (it != it_end)
{
// No constants, nothing completely unfixed.
if ( (it->second)->countFixed() == 0 )
{
delete it->second;
// making this a reference causes reading from freed memory.
const ASTNode n = it->first;
it++;
fixedMap->map->erase(n);
}
else
it++;
}
#endif
topFixed = false;
}
/* FUNCTION: Typechecker for terms and formulas
*
* TypeChecker: Assumes that the immediate Children of the input
* ASTNode have been typechecked. This function is suitable in
* scenarios like where you are building the ASTNode Tree, and you
* typecheck as you go along. It is not suitable as a general
* typechecker.
*
* If this returns, this ALWAYS returns true. If there is an error it
* will call FatalError() and abort.
*/
bool BVTypeCheck(const ASTNode& n)
{
Kind k = n.GetKind();
//The children of bitvector terms are in turn bitvectors.
const ASTVec& v = n.GetChildren();
if (is_Term_kind(k))
{
switch (k)
{
case BVCONST:
if (BITVECTOR_TYPE != n.GetType())
FatalError("BVTypeCheck: The term t does not typecheck, where t = \n", n);
break;
case SYMBOL:
return true;
case ITE:
if (n.Degree() != 3)
FatalError("BVTypeCheck: should have exactly 3 args\n", n);
if (BOOLEAN_TYPE != n[0].GetType() || (n[1].GetType() != n[2].GetType()))
FatalError("BVTypeCheck: The term t does not typecheck, where t = \n", n);
if (n[1].GetValueWidth() != n[2].GetValueWidth())
FatalError("BVTypeCheck: length of THENbranch != length of ELSEbranch in the term t = \n", n);
if (n[1].GetIndexWidth() != n[2].GetIndexWidth())
FatalError("BVTypeCheck: length of THENbranch != length of ELSEbranch in the term t = \n", n);
break;
case READ:
if (n.GetChildren().size() !=2)
FatalError("2 params to read.");
if (n[0].GetIndexWidth() != n[1].GetValueWidth())
{
cerr << "Length of indexwidth of array: " << n[0] << " is : " << n[0].GetIndexWidth() << endl;
cerr << "Length of the actual index is: " << n[1] << " is : " << n[1].GetValueWidth() << endl;
FatalError("BVTypeCheck: length of indexwidth of array != length of actual index in the term t = \n", n);
}
if (ARRAY_TYPE != n[0].GetType())
FatalError("First parameter to read should be an array", n[0]);
if (BITVECTOR_TYPE != n[1].GetType())
FatalError("Second parameter to read should be a bitvector", n[1]);
break;
case WRITE:
if (n.GetChildren().size() !=3)
FatalError("3 params to write.");
if (n[0].GetIndexWidth() != n[1].GetValueWidth())
FatalError("BVTypeCheck: length of indexwidth of array != length of actual index in the term t = \n", n);
if (n[0].GetValueWidth() != n[2].GetValueWidth())
FatalError("BVTypeCheck: valuewidth of array != length of actual value in the term t = \n", n);
if (ARRAY_TYPE != n[0].GetType())
FatalError("First parameter to read should be an array", n[0]);
if (BITVECTOR_TYPE != n[1].GetType())
FatalError("Second parameter to read should be a bitvector", n[1]);
if (BITVECTOR_TYPE != n[2].GetType())
FatalError("Third parameter to read should be a bitvector", n[2]);
break;
case BVDIV:
case BVMOD:
case BVSUB:
case SBVDIV:
case SBVREM:
case SBVMOD:
case BVLEFTSHIFT:
case BVRIGHTSHIFT:
case BVSRSHIFT:
case BVVARSHIFT:
if (n.Degree() != 2)
FatalError("BVTypeCheck: should have exactly 2 args\n", n);
// run on.
case BVOR:
case BVAND:
case BVXOR:
case BVNOR:
case BVNAND:
case BVXNOR:
case BVPLUS:
case BVMULT:
{
if (!(v.size() >= 2))
FatalError("BVTypeCheck:bitwise Booleans and BV arith operators must have at least two arguments\n", n);
unsigned int width = n.GetValueWidth();
for (ASTVec::const_iterator it = v.begin(), itend = v.end(); it != itend; it++)
{
if (width != it->GetValueWidth())
{
cerr << "BVTypeCheck:Operands of bitwise-Booleans and BV arith operators must be of equal length\n";
cerr << n << endl;
cerr << "width of term:" << width << endl;
cerr << "width of offending operand:" << it->GetValueWidth() << endl;
FatalError("BVTypeCheck:Offending operand:\n", *it);
}
if (BITVECTOR_TYPE != it->GetType())
FatalError("BVTypeCheck: ChildNodes of bitvector-terms must be bitvectors\n", n);
}
break;
}
case BVSX:
case BVZX:
//in BVSX(n[0],len), the length of the BVSX term must be
//greater than the length of n[0]
if (n[0].GetValueWidth() > n.GetValueWidth()) {
FatalError(
"BVTypeCheck: BV[SZ]X(t,bv[sz]x_len) : length of 't' must be <= bv[sz]x_len\n",
n);
}
if ((v.size() != 2))
FatalError(
"BVTypeCheck:BV[SZ]X must have two arguments. The second is the new width\n",
n);
break;
case BVCONCAT:
checkChildrenAreBV(v, n);
if (n.Degree() != 2)
FatalError("BVTypeCheck: should have exactly 2 args\n", n);
if (n.GetValueWidth() != n[0].GetValueWidth()
+ n[1].GetValueWidth())
FatalError("BVTypeCheck:BVCONCAT: lengths do not add up\n", n);
break;
case BVUMINUS:
case BVNEG:
checkChildrenAreBV(v, n);
if (n.Degree() != 1)
FatalError("BVTypeCheck: should have exactly 1 args\n", n);
break;
case BVEXTRACT:
checkChildrenAreBV(v, n);
if (n.Degree() != 3)
FatalError("BVTypeCheck: should have exactly 3 args\n", n);
if (!(BVCONST == n[1].GetKind() && BVCONST == n[2].GetKind()))
FatalError("BVTypeCheck: indices should be BVCONST\n", n);
if (n.GetValueWidth() != n[1].GetUnsignedConst()
- n[2].GetUnsignedConst() + 1)
FatalError("BVTypeCheck: length mismatch\n", n);
if (n[1].GetUnsignedConst() >= n[0].GetValueWidth())
FatalError(
"BVTypeCheck: Top index of select is greater or equal to the bitwidth.\n",
n);
break;
default:
cerr << _kind_names[k];
FatalError("No type checking for type");
break;
}
}
else
{
if (!(is_Form_kind(k) && BOOLEAN_TYPE == n.GetType()))
FatalError("BVTypeCheck: not a formula:", n);
switch (k)
{
case TRUE:
case FALSE:
case SYMBOL:
return true;
case BOOLEXTRACT:
checkChildrenAreBV(v, n);
if (n.Degree() != 2)
FatalError("BVTypeCheck: should have exactly 2 args\n", n);
if (!(BVCONST == n[1].GetKind()))
FatalError("BVTypeCheck: index should be BVCONST\n", n);
if (n[1].GetUnsignedConst() >= n[0].GetValueWidth())
FatalError("BVTypeCheck: index is greater or equal to the bitwidth.\n", n);
break;
case PARAMBOOL:
if(2 != n.Degree())
FatalError("BVTypeCheck: PARAMBOOL formula can have exactly two childNodes", n);
break;
case EQ:
if (n.Degree() != 2)
FatalError("BVTypeCheck: should have exactly 2 args\n", n);
if (!(n[0].GetValueWidth() == n[1].GetValueWidth() && n[0].GetIndexWidth() == n[1].GetIndexWidth()))
{
cerr << "valuewidth of lhs of EQ: " << n[0].GetValueWidth() << endl;
cerr << "valuewidth of rhs of EQ: " << n[1].GetValueWidth() << endl;
cerr << "indexwidth of lhs of EQ: " << n[0].GetIndexWidth() << endl;
cerr << "indexwidth of rhs of EQ: " << n[1].GetIndexWidth() << endl;
FatalError("BVTypeCheck: terms in atomic formulas must be of equal length", n);
}
break;
case BVLT:
case BVLE:
case BVGT:
case BVGE:
case BVSLT:
case BVSLE:
case BVSGT:
case BVSGE:
if (n.Degree() != 2)
FatalError("BVTypeCheck: should have exactly 2 args\n", n);
if (BITVECTOR_TYPE != n[0].GetType() && BITVECTOR_TYPE != n[1].GetType())
FatalError("BVTypeCheck: terms in atomic formulas must be bitvectors", n);
if (n[0].GetValueWidth() != n[1].GetValueWidth())
FatalError("BVTypeCheck: terms in atomic formulas must be of equal length", n);
if (n[0].GetIndexWidth() != n[1].GetIndexWidth())
FatalError("BVTypeCheck: terms in atomic formulas must be of equal length", n);
break;
case NOT:
if (1 != n.Degree())
FatalError("BVTypeCheck: NOT formula can have exactly one childNode", n);
break;
case AND:
case OR:
case XOR:
case NAND:
case NOR:
if (2 > n.Degree())
FatalError("BVTypeCheck: AND/OR/XOR/NAND/NOR: must have atleast 2 ChildNodes", n);
break;
case IFF:
case IMPLIES:
if (2 != n.Degree())
FatalError("BVTypeCheck:IFF/IMPLIES must have exactly 2 ChildNodes", n);
break;
case ITE:
if (3 != n.Degree())
FatalError("BVTypeCheck:ITE must have exactly 3 ChildNodes", n);
break;
default:
FatalError("BVTypeCheck: Unrecognized kind: ");
break;
}
}
return true;
} //End of TypeCheck function
bool BVTypeCheck_nonterm_kind(const ASTNode& n, const Kind& k)
{
// The children of bitvector terms are in turn bitvectors.
const ASTVec& v = n.GetChildren();
if (!(is_Form_kind(k) && BOOLEAN_TYPE == n.GetType()))
FatalError("BVTypeCheck: not a formula:", n);
switch (k)
{
case TRUE:
case FALSE:
case SYMBOL:
return true;
case BOOLEXTRACT:
checkChildrenAreBV(v, n);
if (n.Degree() != 2)
FatalError("BVTypeCheck: should have exactly 2 args\n", n);
if (!(BVCONST == n[1].GetKind()))
FatalError("BVTypeCheck: index should be BVCONST\n", n);
if (n[1].GetUnsignedConst() >= n[0].GetValueWidth())
{
FatalError(
"BVTypeCheck: index is greater or equal to the bitwidth.\n", n);
}
break;
case PARAMBOOL:
if (2 != n.Degree())
{
FatalError(
"BVTypeCheck: PARAMBOOL formula can have exactly two childNodes",
n);
}
break;
case EQ:
if (n.Degree() != 2)
FatalError("BVTypeCheck: should have exactly 2 args\n", n);
if (!(n[0].GetValueWidth() == n[1].GetValueWidth() &&
n[0].GetIndexWidth() == n[1].GetIndexWidth()))
{
cerr << "valuewidth of lhs of EQ: " << n[0].GetValueWidth() << endl;
cerr << "valuewidth of rhs of EQ: " << n[1].GetValueWidth() << endl;
cerr << "indexwidth of lhs of EQ: " << n[0].GetIndexWidth() << endl;
cerr << "indexwidth of rhs of EQ: " << n[1].GetIndexWidth() << endl;
FatalError(
"BVTypeCheck: terms in atomic formulas must be of equal length",
n);
}
break;
case BVLT:
case BVLE:
case BVGT:
case BVGE:
case BVSLT:
case BVSLE:
case BVSGT:
case BVSGE:
if (n.Degree() != 2)
FatalError("BVTypeCheck: should have exactly 2 args\n", n);
if (BITVECTOR_TYPE != n[0].GetType() &&
BITVECTOR_TYPE != n[1].GetType())
{
FatalError("BVTypeCheck: terms in atomic formulas must be bitvectors"
,n);
}
if (n[0].GetValueWidth() != n[1].GetValueWidth())
FatalError(
"BVTypeCheck: terms in atomic formulas must be of equal length",
n);
if (n[0].GetIndexWidth() != n[1].GetIndexWidth())
{
FatalError(
"BVTypeCheck: terms in atomic formulas must be of equal length",
n);
}
break;
case NOT:
if (1 != n.Degree())
{
FatalError("BVTypeCheck: NOT formula can have exactly one childNode",
n);
}
break;
case AND:
case OR:
case XOR:
case NAND:
case NOR:
if (2 > n.Degree())
{
FatalError("BVTypeCheck: AND/OR/XOR/NAND/NOR: must have atleast 2 "
"ChildNodes",
n);
}
break;
case IFF:
case IMPLIES:
if (2 != n.Degree())
{
FatalError("BVTypeCheck:IFF/IMPLIES must have exactly 2 ChildNodes",
n);
}
break;
case ITE:
if (3 != n.Degree())
FatalError("BVTypeCheck:ITE must have exactly 3 ChildNodes", n);
break;
default:
FatalError("BVTypeCheck: Unrecognized kind: ");
break;
}
return true;
}
bool BVTypeCheck_term_kind(const ASTNode& n, const Kind& k)
{
// The children of bitvector terms are in turn bitvectors.
const ASTVec& v = n.GetChildren();
switch (k)
{
case BVCONST:
if (BITVECTOR_TYPE != n.GetType())
FatalError("BVTypeCheck: The term t does not typecheck, where t = \n",
n);
break;
case SYMBOL:
return true;
case ITE:
if (n.Degree() != 3)
FatalError("BVTypeCheck: should have exactly 3 args\n", n);
if (BOOLEAN_TYPE != n[0].GetType() ||
(n[1].GetType() != n[2].GetType()))
FatalError("BVTypeCheck: The term t does not typecheck, where t = \n",
n);
if (n[1].GetValueWidth() != n[2].GetValueWidth())
FatalError("BVTypeCheck: length of THENbranch != length of "
"ELSEbranch in the term t = \n",
n);
if (n[1].GetIndexWidth() != n[2].GetIndexWidth())
FatalError("BVTypeCheck: length of THENbranch != length of "
"ELSEbranch in the term t = \n",
n);
break;
case READ:
if (n.GetChildren().size() != 2)
FatalError("2 params to read.");
if (n[0].GetIndexWidth() != n[1].GetValueWidth())
{
cerr << "Length of indexwidth of array: " << n[0]
<< " is : " << n[0].GetIndexWidth() << endl;
cerr << "Length of the actual index is: " << n[1]
<< " is : " << n[1].GetValueWidth() << endl;
FatalError("BVTypeCheck: length of indexwidth of array != length of "
"actual index in the term t = \n",
n);
}
if (ARRAY_TYPE != n[0].GetType())
FatalError("First parameter to read should be an array", n[0]);
if (BITVECTOR_TYPE != n[1].GetType())
FatalError("Second parameter to read should be a bitvector", n[1]);
break;
case WRITE:
if (n.GetChildren().size() != 3)
FatalError("3 params to write.");
if (n[0].GetIndexWidth() != n[1].GetValueWidth())
FatalError("BVTypeCheck: length of indexwidth of array != length of "
"actual index in the term t = \n",
n);
if (n[0].GetValueWidth() != n[2].GetValueWidth())
FatalError("BVTypeCheck: valuewidth of array != length of actual "
"value in the term t = \n",
n);
if (ARRAY_TYPE != n[0].GetType())
FatalError("First parameter to read should be an array", n[0]);
if (BITVECTOR_TYPE != n[1].GetType())
FatalError("Second parameter to read should be a bitvector", n[1]);
if (BITVECTOR_TYPE != n[2].GetType())
FatalError("Third parameter to read should be a bitvector", n[2]);
break;
case BVDIV:
case BVMOD:
case BVSUB:
case SBVDIV:
case SBVREM:
case SBVMOD:
case BVLEFTSHIFT:
case BVRIGHTSHIFT:
case BVSRSHIFT:
case BVVARSHIFT:
if (n.Degree() != 2)
FatalError("BVTypeCheck: should have exactly 2 args\n", n);
// run on.
case BVOR:
case BVAND:
case BVXOR:
case BVNOR:
case BVNAND:
case BVXNOR:
case BVPLUS:
case BVMULT:
{
if (!(v.size() >= 2))
FatalError("BVTypeCheck:bitwise Booleans and BV arith operators must "
"have at least two arguments\n",n);
unsigned int width = n.GetValueWidth();
for (ASTVec::const_iterator it = v.begin(), itend = v.end();
it != itend; it++)
{
if (width != it->GetValueWidth())
{
cerr << "BVTypeCheck:Operands of bitwise-Booleans and BV arith "
"operators must be of equal length\n";
cerr << n << endl;
cerr << "width of term:" << width << endl;
cerr << "width of offending operand:" << it->GetValueWidth()
<< endl;
FatalError("BVTypeCheck:Offending operand:\n", *it);
}
if (BITVECTOR_TYPE != it->GetType())
FatalError("BVTypeCheck: ChildNodes of bitvector-terms must be "
"bitvectors\n", n);
}
break;
}
case BVSX:
case BVZX:
// in BVSX(n[0],len), the length of the BVSX term must be
// greater than the length of n[0]
if (n[0].GetValueWidth() > n.GetValueWidth())
{
FatalError("BVTypeCheck: BV[SZ]X(t,bv[sz]x_len) : length of 't' must "
"be <= bv[sz]x_len\n", n);
}
if ((v.size() != 2))
FatalError("BVTypeCheck:BV[SZ]X must have two arguments. The second "
"is the new width\n", n);
break;
case BVCONCAT:
checkChildrenAreBV(v, n);
if (n.Degree() != 2)
FatalError("BVTypeCheck: should have exactly 2 args\n", n);
if (n.GetValueWidth() != n[0].GetValueWidth() + n[1].GetValueWidth())
FatalError("BVTypeCheck:BVCONCAT: lengths do not add up\n", n);
break;
case BVUMINUS:
case BVNEG:
checkChildrenAreBV(v, n);
if (n.Degree() != 1)
FatalError("BVTypeCheck: should have exactly 1 args\n", n);
if (n.GetValueWidth() != n[0].GetValueWidth())
FatalError("BVTypeCheck: should have same value width\n", n);
break;
case BVEXTRACT:
checkChildrenAreBV(v, n);
if (n.Degree() != 3)
FatalError("BVTypeCheck: should have exactly 3 args\n", n);
if (!(BVCONST == n[1].GetKind() && BVCONST == n[2].GetKind()))
FatalError("BVTypeCheck: indices should be BVCONST\n", n);
if (n.GetValueWidth() !=
n[1].GetUnsignedConst() - n[2].GetUnsignedConst() + 1)
FatalError("BVTypeCheck: length mismatch\n", n);
if (n[1].GetUnsignedConst() >= n[0].GetValueWidth())
FatalError("BVTypeCheck: Top index of select is greater or equal to "
"the bitwidth.\n",
n);
break;
default:
cerr << _kind_names[k];
FatalError("No type checking for type");
break;
}
return true;
}
// This doesn't rewrite changes through properly so needs to have a substitution
// applied to its output.
ASTNode PropagateEqualities::propagate(const ASTNode& a, ArrayTransformer* at)
{
ASTNode output;
// if the variable has been solved for, then simply return it
if (simp->InsideSubstitutionMap(a, output))
return output;
if (!alreadyVisited.insert(a.GetNodeNum()).second)
{
return a;
}
output = a;
// traverse a and populate the SubstitutionMap
const Kind k = a.GetKind();
if (SYMBOL == k && BOOLEAN_TYPE == a.GetType())
{
bool updated = simp->UpdateSubstitutionMap(a, ASTTrue);
output = updated ? ASTTrue : a;
}
else if (NOT == k)
{
bool updated = searchXOR(a[0], ASTFalse);
output = updated ? ASTTrue : a;
}
else if (IFF == k || EQ == k)
{
const ASTVec& c = a.GetChildren();
if (c[0] == c[1])
return ASTTrue;
bool updated = simp->UpdateSubstitutionMap(c[0], c[1]);
if (updated)
{
// fill the arrayname readindices vector if e0 is a
// READ(Arr,index) and index is a BVCONST
int to;
if ((to = TermOrder(c[0], c[1])) == 1 && c[0].GetKind() == READ)
at->FillUp_ArrReadIndex_Vec(c[0], c[1]);
else if (to == -1 && c[1].GetKind() == READ)
at->FillUp_ArrReadIndex_Vec(c[1], c[0]);
}
if (!updated)
updated = searchTerm(c[0], c[1]);
if (!updated)
updated = searchTerm(c[1], c[0]);
output = updated ? ASTTrue : a;
}
else if (XOR == k)
{
bool updated = searchXOR(a, ASTTrue);
output = updated ? ASTTrue : a;
if (updated)
return output;
// The below block should be subsumed by the searchXOR function which
// generalises it.
// So the below block should never do anything..
#ifndef NDEBUG
if (a.Degree() != 2)
return output;
int to = TermOrder(a[0], a[1]);
if (0 == to)
{
if (a[0].GetKind() == NOT && a[0][0].GetKind() == EQ &&
a[0][0][0].GetValueWidth() == 1 && a[0][0][1].GetKind() == SYMBOL)
{
// (XOR (NOT(= (1 v))) ... )
const ASTNode& symbol = a[0][0][1];
const ASTNode newN = nf->CreateTerm(
ITE, 1, a[1], a[0][0][0], nf->CreateTerm(BVNEG, 1, a[0][0][0]));
if (simp->UpdateSolverMap(symbol, newN))
{
assert(false);
output = ASTTrue;
}
}
else if (a[1].GetKind() == NOT && a[1][0].GetKind() == EQ &&
a[1][0][0].GetValueWidth() == 1 &&
a[1][0][1].GetKind() == SYMBOL)
{
const ASTNode& symbol = a[1][0][1];
const ASTNode newN = nf->CreateTerm(
ITE, 1, a[0], a[1][0][0], nf->CreateTerm(BVNEG, 1, a[1][0][0]));
if (simp->UpdateSolverMap(symbol, newN))
{
assert(false);
output = ASTTrue;
}
}
else if (a[0].GetKind() == EQ && a[0][0].GetValueWidth() == 1 &&
a[0][1].GetKind() == SYMBOL)
{
// XOR ((= 1 v) ... )
const ASTNode& symbol = a[0][1];
const ASTNode newN = nf->CreateTerm(
ITE, 1, a[1], nf->CreateTerm(BVNEG, 1, a[0][0]), a[0][0]);
if (simp->UpdateSolverMap(symbol, newN))
{
assert(false);
output = ASTTrue;
}
}
else if (a[1].GetKind() == EQ && a[1][0].GetValueWidth() == 1 &&
a[1][1].GetKind() == SYMBOL)
{
const ASTNode& symbol = a[1][1];
const ASTNode newN = nf->CreateTerm(
ITE, 1, a[0], nf->CreateTerm(BVNEG, 1, a[1][0]), a[1][0]);
if (simp->UpdateSolverMap(symbol, newN))
{
assert(false);
output = ASTTrue;
}
}
else
return output;
}
else
{
ASTNode symbol, rhs;
if (to == 1)
{
symbol = a[0];
rhs = a[1];
}
else
{
symbol = a[1];
rhs = a[0];
}
assert(symbol.GetKind() == SYMBOL);
if (simp->UpdateSolverMap(symbol, nf->CreateNode(NOT, rhs)))
{
assert(false);
output = ASTTrue;
}
}
#endif
}
else if (AND == k)
{
const ASTVec& c = a.GetChildren();
ASTVec o;
o.reserve(c.size());
for (ASTVec::const_iterator it = c.begin(), itend = c.end(); it != itend;
it++)
{
if (always_true)
simp->UpdateAlwaysTrueFormSet(*it);
ASTNode aaa = propagate(*it, at);
if (ASTTrue != aaa)
{
if (ASTFalse == aaa)
return ASTFalse;
else
o.push_back(aaa);
}
}
if (o.size() == 0)
output = ASTTrue;
else if (o.size() == 1)
output = o[0];
else if (o != c)
output = nf->CreateNode(AND, o);
else
output = a;
}
return output;
}
/* This function transforms Array Reads, Read over Writes, Read over
* ITEs into flattened form.
*
* Transform1: Suppose there are two array reads in the input
* Read(A,i) and Read(A,j) over the same array. Then Read(A,i) is
* replaced with a symbolic constant, say v1, and Read(A,j) is
* replaced with the following ITE:
*
* ITE(i=j,v1,v2)
*
*/
ASTNode ArrayTransformer::TransformArrayRead(const ASTNode& term)
{
assert(TransformMap != NULL);
const unsigned int width = term.GetValueWidth();
if (READ != term.GetKind())
return term;
ASTNodeMap::const_iterator iter;
if ((iter = TransformMap->find(term)) != TransformMap->end())
return iter->second;
//'term' is of the form READ(arrName, readIndex)
const ASTNode& arrName = term[0];
const ASTNode& readIndex = TransformTerm(term[1]);
ASTNode result;
switch (arrName.GetKind())
{
case SYMBOL:
{
/* input is of the form: READ(A, readIndex)
*
* output is of the from: A1, if this is the first READ over A
*
* ITE(previous_readIndex=readIndex,A1,A2)
*
* .....
*/
{
ArrType::const_iterator it;
if ((it = arrayToIndexToRead.find(arrName)) != arrayToIndexToRead.end())
{
std::map<ASTNode, ArrayRead>::const_iterator it2;
if ((it2 = it->second.find(readIndex)) != it->second.end())
{
result = it2->second.ite;
break;
}
}
}
// Make up a new abstract variable. Build symbolic name
// corresponding to array read. The symbolic name has 2
// components: stringname, and a count
ASTNode CurrentSymbol =
bm->CreateFreshVariable(term.GetIndexWidth(), term.GetValueWidth(),
"array_" + std::string(arrName.GetName()));
result = CurrentSymbol;
if (!bm->UserFlags.ackermannisation)
{
// result is a variable here; it is an ite in the
// else-branch
}
else if (bm->UserFlags.isSet("old_ack", "0"))
{
/* oops.
* This version of ack. doesn't do what I thought it did. The STP 0.1
* version of Ack. produces simpler
* expressions. I've put that in the next block. Trevor's thesis
* measures AckITE using this implementation,
* rather than the next one like it should have!!!!
*/
// Full Array transform if we're not doing read refinement.
// list of array-read indices corresponding to arrName, seen while
// traversing the AST tree. we need this list to construct the ITEs
const arrTypeMap& new_read_Indices = arrayToIndexToRead[arrName];
arrTypeMap::const_iterator it2 = new_read_Indices.begin();
arrTypeMap::const_iterator it2end = new_read_Indices.end();
for (; it2 != it2end; it2++)
{
ASTNode cond = simp->CreateSimplifiedEQ(readIndex, it2->first);
if (ASTFalse == cond)
continue;
if (ASTTrue == cond)
{
result = it2->second.ite;
break;
}
result = simp->CreateSimplifiedTermITE(cond, it2->second.ite, result);
}
}
else
{
// Full Array transform if we're not doing read refinement.
// list of array-read indices corresponding to arrName, seen while
// traversing the AST tree. we need this list to construct the ITEs
vector<std::pair<ASTNode, ASTNode>> p = ack_pair[arrName];
vector<std::pair<ASTNode, ASTNode>>::const_reverse_iterator it2 =
p.rbegin();
vector<std::pair<ASTNode, ASTNode>>::const_reverse_iterator it2end =
p.rend();
for (; it2 != it2end; it2++)
{
ASTNode cond = simp->CreateSimplifiedEQ(readIndex, it2->first);
if (ASTFalse == cond)
continue;
if (ASTTrue == cond)
{
result = it2->second;
break;
}
result = simp->CreateSimplifiedTermITE(cond, it2->second, result);
}
ack_pair[arrName].push_back(make_pair(readIndex, CurrentSymbol));
}
assert(arrName.GetType() == ARRAY_TYPE);
arrayToIndexToRead[arrName].insert(
make_pair(readIndex, ArrayRead(result, CurrentSymbol)));
break;
}
case WRITE:
{
/* The input to this case is: READ((WRITE A i val) j)
*
* The output of this case is: ITE( (= i j) val (READ A j))
*/
/* 1. arrName or term[0] is infact a WRITE(A,i,val) expression
*
* 2. term[1] is the read-index j
*
* 3. arrName[0] is the new arrName i.e. A. A can be either a
SYMBOL or a nested WRITE. no other possibility
*
* 4. arrName[1] is the WRITE index i.e. i
*
* 5. arrName[2] is the WRITE value i.e. val (val can inturn
* be an array read)
*/
ASTNode writeIndex = TransformTerm(arrName[1]);
ASTNode writeVal = TransformTerm(arrName[2]);
if (ARRAY_TYPE != arrName[0].GetType())
FatalError("TransformArray: "
"An array write is being attempted on a non-array:",
term);
// if ((SYMBOL == arrName[0].GetKind()
//|| WRITE == arrName[0].GetKind()))
{
ASTNode cond = simp->CreateSimplifiedEQ(writeIndex, readIndex);
assert(BVTypeCheck(cond));
// If the condition is true, it saves iteratively transforming through
// all the (possibly nested) arrays.
if (ASTTrue == cond)
{
result = writeVal;
}
else
{
ASTNode readTerm = nf->CreateTerm(READ, width, arrName[0], readIndex);
assert(BVTypeCheck(readTerm));
// The simplifying node factory may have produced
// something that's not a READ.
ASTNode readPushedIn = TransformTerm(readTerm);
assert(BVTypeCheck(readPushedIn));
result = simp->CreateSimplifiedTermITE(cond, writeVal, readPushedIn);
}
}
// Trevor: I've removed this code because I don't see the advantage in working
// inside out. i.e. transforming read(write(ite(p,A,B),i,j),k), into
// read(ite(p,write(A,i,j),write(B,i,j),k). That is bringing up the ite.
// Without this code it will become: ite(i=k, j, read(ite(p,A,B),k))
#if 0
else if (ITE == arrName[0].GetKind())
{
// pull out the ite from the write // pushes the write
// through.
ASTNode writeTrue =
nf->CreateNode(WRITE, (arrName[0][1]), writeIndex, writeVal);
writeTrue.SetIndexWidth(writeIndex.GetValueWidth());
writeTrue.SetValueWidth(writeVal.GetValueWidth());
assert(ARRAY_TYPE == writeTrue.GetType());
ASTNode writeFalse =
nf->CreateNode(WRITE, (arrName[0][2]), writeIndex, writeVal);
writeFalse.SetIndexWidth(writeIndex.GetValueWidth());
writeFalse.SetValueWidth(writeVal.GetValueWidth());
assert(ARRAY_TYPE == writeFalse.GetType());
result = (writeTrue == writeFalse) ?
writeTrue : simp->CreateSimplifiedTermITE(TransformFormula(arrName[0][0]),
writeTrue, writeFalse);
result.SetIndexWidth(writeIndex.GetValueWidth());
result.SetValueWidth(writeVal.GetValueWidth());
assert(ARRAY_TYPE == result.GetType());
result =
nf->CreateTerm(READ, writeVal.GetValueWidth(),
result, readIndex);
BVTypeCheck(result);
result = TransformArrayRead(result);
}
else
FatalError("TransformArray: Write over bad type.");
#endif
break;
}
case ITE:
{
/* READ((ITE cond thn els) j)
*
* is transformed into
*
* (ITE cond (READ thn j) (READ els j))
*/
// pull out the ite from the read // pushes the read through.
//(ITE cond thn els)
ASTNode cond = arrName[0];
cond = TransformFormula(cond);
const ASTNode& thn = arrName[1];
const ASTNode& els = arrName[2];
//(READ thn j)
ASTNode thnRead = nf->CreateTerm(READ, width, thn, readIndex);
assert(BVTypeCheck(thnRead));
//(READ els j)
ASTNode elsRead = nf->CreateTerm(READ, width, els, readIndex);
assert(BVTypeCheck(elsRead));
/* We try to call TransformTerm only if necessary, because it
* introduces a new symbol for each read. The amount of work we
* need to do later is based on the square of the number of symbols.
*/
if (ASTTrue == cond)
{
result = TransformTerm(thnRead);
}
else if (ASTFalse == cond)
{
result = TransformTerm(elsRead);
}
else
{
thnRead = TransformTerm(thnRead);
elsRead = TransformTerm(elsRead);
//(ITE cond (READ thn j) (READ els j))
result = simp->CreateSimplifiedTermITE(cond, thnRead, elsRead);
}
break;
}
default:
FatalError("TransformArray: "
"The READ is NOT over SYMBOL/WRITE/ITE",
term);
break;
}
/********************************************************
* TransformFormula()
*
* Get rid of DIV/MODs, ARRAY read/writes, FOR constructs
********************************************************/
ASTNode ArrayTransformer::TransformFormula(const ASTNode& simpleForm)
{
assert(TransformMap != NULL);
const Kind k = simpleForm.GetKind();
if (!(is_Form_kind(k) && BOOLEAN_TYPE == simpleForm.GetType()))
{
// FIXME: "You have inputted a NON-formula"?
FatalError("TransformFormula:"
"You have input a NON-formula",
simpleForm);
}
ASTNodeMap::const_iterator iter;
if ((iter = TransformMap->find(simpleForm)) != TransformMap->end())
return iter->second;
ASTNode result;
switch (k)
{
case TRUE:
case FALSE:
{
result = simpleForm;
break;
}
case NOT:
{
ASTVec c;
c.push_back(TransformFormula(simpleForm[0]));
result = nf->CreateNode(NOT, c);
break;
}
case BOOLEXTRACT:
{
ASTVec c;
c.push_back(TransformTerm(simpleForm[0]));
c.push_back(simpleForm[1]);
result = nf->CreateNode(BOOLEXTRACT, c);
break;
}
case BVLT:
case BVLE:
case BVGT:
case BVGE:
case BVSLT:
case BVSLE:
case BVSGT:
case BVSGE:
{
ASTVec c;
c.push_back(TransformTerm(simpleForm[0]));
c.push_back(TransformTerm(simpleForm[1]));
result = nf->CreateNode(k, c);
break;
}
case EQ:
{
ASTNode term1 = TransformTerm(simpleForm[0]);
ASTNode term2 = TransformTerm(simpleForm[1]);
if (bm->UserFlags.optimize_flag)
result = simp->CreateSimplifiedEQ(term1, term2);
else
result = nf->CreateNode(EQ, term1, term2);
break;
}
case AND: // These could shortcut. Not sure if the extra effort is
// justified.
case OR:
case NAND:
case NOR:
case IFF:
case XOR:
case ITE:
case IMPLIES:
{
ASTVec vec;
vec.reserve(simpleForm.Degree());
for (ASTVec::const_iterator it = simpleForm.begin(),
itend = simpleForm.end();
it != itend; it++)
{
vec.push_back(TransformFormula(*it));
}
result = nf->CreateNode(k, vec);
break;
}
case PARAMBOOL:
{
// If the parameteric boolean variable is of the form
// VAR(const), then convert it into a Boolean variable of the
// form "VAR(const)".
//
// Else if the paramteric boolean variable is of the form
// VAR(expression), then simply return it
if (BVCONST == simpleForm[1].GetKind())
{
result = bm->NewParameterized_BooleanVar(simpleForm[0], simpleForm[1]);
}
else
{
result = simpleForm;
}
break;
}
default:
{
if (k == SYMBOL && BOOLEAN_TYPE == simpleForm.GetType())
result = simpleForm;
else
{
FatalError("TransformFormula: Illegal kind: ", ASTUndefined, k);
std::cerr << "The input is: " << simpleForm << std::endl;
std::cerr << "The valuewidth of input is : "
<< simpleForm.GetValueWidth() << std::endl;
}
break;
}
}
assert(!result.IsNull());
if (simpleForm.Degree() > 0)
(*TransformMap)[simpleForm] = result;
return result;
}
// NB: This expects that the constructor was called with teh same node. Sorry.
ASTNode
ConstantBitPropagation::topLevelBothWays(const ASTNode& top)
{
assert(top.GetSTPMgr()->UserFlags.bitConstantProp_flag);
assert (BOOLEAN_TYPE == top.GetType());
propagate();
status = NO_CHANGE;
//Determine what must always be true.
ASTNodeMap fromTo = getAllFixed();
if (debug_cBitProp_messages)
{
cerr << "Number removed by bottom UP:" << fromTo.size() << endl;
}
setNodeToTrue(top);
if (debug_cBitProp_messages)
{
cerr << "starting propagation" << endl;
printNodeWithFixings();
cerr << "Initial Tree:" << endl;
cerr << top;
}
propagate();
if (debug_cBitProp_messages)
{
cerr << "status:" << status <<endl;
cerr << "ended propagation" << endl;
printNodeWithFixings();
}
// propagate may have stopped with a conflict.
if (CONFLICT == status)
return top.GetSTPMgr()->CreateNode(FALSE);
ASTVec toConjoin;
// go through the fixedBits. If a node is entirely fixed.
// "and" it onto the top. Creates redundancy. Check that the
// node doesn't already depend on "top" directly.
for (NodeToFixedBitsMap::NodeToFixedBitsMapType::iterator it = fixedMap->map->begin(); it != fixedMap->map->end(); it++) // iterates through all the pairs of node->fixedBits.
{
const FixedBits& bits = *it->second;
if (!bits.isTotallyFixed())
continue;
const ASTNode& node = (it->first);
// Don't constrain nodes we already know all about.
if (node.isConstant())
continue;
// other nodes will contain the same information (the extract doesn't change the fixings).
if (BVEXTRACT == node.GetKind() || BVCONCAT == node.GetKind())
continue;
// toAssign: conjoin it with the top level.
// toReplace: replace all references to it (except the one conjoined to the top) with this.
ASTNode propositionToAssert;
ASTNode constantToReplaceWith;
// skip the assigning and replacing.
bool doAssign = true;
{
// If it is already contained in the fromTo map, then it's one of the values
// that have fully been determined (previously). Not conjoined.
if (fromTo.find(node) != fromTo.end())
continue;
ASTNode constNode = bitsToNode(node,bits);
if (node.GetType() == BOOLEAN_TYPE)
{
if (SYMBOL == node.GetKind())
{
bool r = simplifier->UpdateSubstitutionMap(node, constNode);
assert(r);
doAssign = false;
}
else if (bits.getValue(0))
{
propositionToAssert = node;
constantToReplaceWith = constNode;
}
else
{
propositionToAssert = nf->CreateNode(NOT, node);
constantToReplaceWith = constNode;
}
}
else if (node.GetType() == BITVECTOR_TYPE)
{
assert(((unsigned)bits.getWidth()) == node.GetValueWidth());
if (SYMBOL == node.GetKind())
{
bool r = simplifier->UpdateSubstitutionMap(node, constNode);
assert(r);
doAssign = false;
}
else
{
propositionToAssert = nf->CreateNode(EQ, node, constNode);
constantToReplaceWith = constNode;
}
}
else
FatalError("sadf234s");
}
if (doAssign && top != propositionToAssert
&& !dependents->nodeDependsOn(top, propositionToAssert))
{
assert(!constantToReplaceWith.IsNull());
assert(constantToReplaceWith.isConstant());
assert(propositionToAssert.GetType() == BOOLEAN_TYPE);
assert(node.GetValueWidth() == constantToReplaceWith.GetValueWidth());
fromTo.insert(make_pair(node, constantToReplaceWith));
toConjoin.push_back(propositionToAssert);
}
}
// Write the constants into the main graph.
ASTNodeMap cache;
ASTNode result = SubstitutionMap::replace(top, fromTo, cache,nf);
if (0 != toConjoin.size())
{
// It doesn't happen very often. But the "toConjoin" might contain a variable
// that was added to the substitution map (because the value was determined just now
// during propagation.
ASTNode conjunct = (1 == toConjoin.size())? toConjoin[0]: nf->CreateNode(AND,toConjoin);
conjunct = simplifier->applySubstitutionMap(conjunct);
result = nf->CreateNode(AND, result, conjunct); // conjoin the new conditions.
}
if (debug_print_graph_after)
{
ofstream file;
file.open("afterCbitp.gdl");
PrintingHackfixedMap = fixedMap;
printer::GDL_Print(file,top,&toString);
file.close();
}
assert(BVTypeCheck(result));
assert(status != CONFLICT); // conflict should have been seen earlier.
return result;
}