ASTNode ArrayTransformer::TransformTerm(const ASTNode& term)
{
assert(TransformMap != NULL);
const Kind k = term.GetKind();
if (!is_Term_kind(k))
FatalError("TransformTerm: Illegal kind: You have input a nonterm:", term,
k);
ASTNodeMap::const_iterator iter;
if ((iter = TransformMap->find(term)) != TransformMap->end())
return iter->second;
ASTNode result;
switch (k)
{
case SYMBOL:
case BVCONST:
{
result = term;
break;
}
case WRITE:
FatalError("TransformTerm: this kind is not supported", term);
break;
case READ:
result = TransformArrayRead(term);
break;
case ITE:
{
ASTNode cond = term[0];
ASTNode thn = term[1];
ASTNode els = term[2];
cond = TransformFormula(cond);
if (ASTTrue == cond)
result = TransformTerm(thn);
else if (ASTFalse == cond)
result = TransformTerm(els);
else
{
thn = TransformTerm(thn);
els = TransformTerm(els);
if (bm->UserFlags.optimize_flag)
result = simp->CreateSimplifiedTermITE(cond, thn, els);
else
result = nf->CreateTerm(ITE, thn.GetValueWidth(), cond, thn, els);
}
assert(result.GetIndexWidth() == term.GetIndexWidth());
break;
}
default:
{
const ASTVec& c = term.GetChildren();
ASTVec::const_iterator it = c.begin();
ASTVec::const_iterator itend = c.end();
const unsigned width = term.GetValueWidth();
const unsigned indexwidth = term.GetIndexWidth();
ASTVec o;
o.reserve(c.size());
for (; it != itend; it++)
{
o.push_back(TransformTerm(*it));
}
if (c != o)
{
result = nf->CreateArrayTerm(k, indexwidth, width, o);
}
else
result = term;
}
break;
}
if (term.Degree() > 0)
(*TransformMap)[term] = result;
if (term.GetValueWidth() != result.GetValueWidth())
FatalError("TransformTerm: "
"result and input terms are of different length",
result);
if (term.GetIndexWidth() != result.GetIndexWidth())
{
std::cerr << "TransformTerm: input term is : " << term << std::endl;
FatalError("TransformTerm: "
"result & input terms have different index length",
result);
}
return result;
}
/* 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
ASTNode ArrayTransformer::TransformTerm(const ASTNode& term)
{
assert(TransformMap != NULL);
const Kind k = term.GetKind();
if (!is_Term_kind(k))
FatalError("TransformTerm: Illegal kind: You have input a nonterm:",
term, k);
ASTNodeMap::const_iterator iter;
if ((iter = TransformMap->find(term)) != TransformMap->end())
return iter->second;
ASTNode result;
switch (k)
{
case SYMBOL:
case BVCONST:
{
result = term;
break;
}
case WRITE:
FatalError("TransformTerm: this kind is not supported", term);
break;
case READ:
result = TransformArrayRead(term);
break;
case ITE:
{
ASTNode cond = term[0];
ASTNode thn = term[1];
ASTNode els = term[2];
cond = TransformFormula(cond);
if (ASTTrue == cond)
result = TransformTerm(thn);
else if (ASTFalse == cond)
result = TransformTerm(els);
else
{
thn = TransformTerm(thn);
els = TransformTerm(els);
result = simp->CreateSimplifiedTermITE(cond, thn, els);
}
assert(result.GetIndexWidth() ==term.GetIndexWidth());
break;
}
default:
{
const ASTVec& c = term.GetChildren();
ASTVec::const_iterator it = c.begin();
ASTVec::const_iterator itend = c.end();
const unsigned width = term.GetValueWidth();
const unsigned indexwidth = term.GetIndexWidth();
ASTVec o;
o.reserve(c.size());
for (; it != itend; it++)
{
o.push_back(TransformTerm(*it));
}
if (c!=o)
{
result = nf->CreateArrayTerm(k,indexwidth, width, o);
}
else
result = term;
const Kind k = result.GetKind();
if (BVDIV == k
|| BVMOD == k
|| SBVDIV == k
|| SBVREM == k
|| SBVMOD == k)
{
// I had this as a reference, but that was wrong. Because
// "result" gets over-written in the next block, result[1], may
// get a reference count of zero, so be garbage collected.
const ASTNode bottom = result[1];
if (SBVDIV == result.GetKind()
|| SBVREM == result.GetKind()
|| SBVMOD == result.GetKind())
{
result = TranslateSignedDivModRem(result);
}
if (bm->UserFlags.division_by_zero_returns_one_flag)
{
// This is a difficult rule to introduce in other
// places because it's recursive. i.e. result is
// embedded unchanged inside the result.
unsigned inputValueWidth = result.GetValueWidth();
ASTNode zero = bm->CreateZeroConst(inputValueWidth);
ASTNode one = bm->CreateOneConst(inputValueWidth);
result =
nf->CreateTerm(ITE, inputValueWidth,
nf->CreateNode(EQ, zero, bottom),
one, result);
//return result;
if (bm->UserFlags.optimize_flag)
return simp->SimplifyTerm_TopLevel(result);
else
return result;
}
}
}
break;
}
if (term.Degree() > 0)
(*TransformMap)[term] = result;
if (term.GetValueWidth() != result.GetValueWidth())
FatalError("TransformTerm: "\
"result and input terms are of different length", result);
if (term.GetIndexWidth() != result.GetIndexWidth())
{
cerr << "TransformTerm: input term is : " << term << endl;
FatalError("TransformTerm: "\
"result & input terms have different index length", result);
}
return result;
} //End of TransformTerm
