public static Z3BVExpr Int2BV(this Z3IntExpr expr1, Z3Context context, uint size)
{
Contract.Requires(expr1 != null && context != null && size > 0);
Z3IntExpr xj, pow;
var xi = new Z3IntExpr[size];
var yi = new Z3BVExpr[size];
var zero = context.MkInt(0);
var one = context.MkInt(1);
var bvzero = context.MkBV(0, size);
var bvone = context.MkBV(1, size);
xi[size - 1] = expr1;
for (int i = ((int)size) - 2; i >= 0; --i)
{
pow = context.MkInt(BigInteger.Pow(2, i + 1).ToString());
xj = xi[i + 1];
xi[i] = (Z3IntExpr)xj.Ge(context, pow).Ite(context, xj.Sub(context, pow), xj);
}
Z3BVExpr coercion = bvzero;
for (int i = ((int)size) - 1; i >= 0; --i)
{
pow = context.MkInt(BigInteger.Pow(2, i).ToString());
coercion = (Z3BVExpr)xi[i].Ge(context, pow).Ite(
context,
context.MkBVAdd(context.MkBVSHL(coercion, bvone), bvone),
context.MkBVSHL(coercion, bvone));
}
Contract.Assert(coercion != null);
return(coercion);
}
/// <summary>
/// Coerces an integer into a natural.
/// </summary>
public Z3Expr MkNegCoercion(Z3IntExpr i)
{
var zero = Context.MkInt(0);
var one = Context.MkInt(1);
var two = Context.MkInt(2);
var oddCase = BoxingFun.Apply(i.Add(Context, one).Div(Context, two));
var coercion = i.IsEven(Context).Ite(
Context,
BoxingFun.Apply(i.Neg(Context).Div(Context, two)),
oddCase);
return(coercion);
}
public static Z3IntExpr BV2Int(this Z3BVExpr expr1, Z3Context context)
{
var size = expr1.SortSize;
var parts = new Z3IntExpr[size];
var zero = context.MkInt(0);
var bvzero = context.MkBV(0, 1);
for (uint i = 0; i < size; ++i)
{
parts[i] = (Z3IntExpr)expr1.Index(context, i).Eq(context, bvzero).Ite(
context,
zero,
context.MkInt(BigInteger.Pow(2, (int)i).ToString()));
}
return((Z3IntExpr)context.MkAdd(parts));
}
/// <summary>
/// Coerces an integer into a pos integer.
/// </summary>
public Z3Expr MkPosCoercion(Z3IntExpr i)
{
var zero = Context.MkInt(0);
var one = Context.MkInt(1);
var two = Context.MkInt(2);
var oddCase = BoxingFun.Apply(one.Sub(Context, i).Div(Context, two));
var coercion = i.IsEven(Context).Ite(
Context,
BoxingFun.Apply(i.Div(Context, two)),
oddCase);
coercion = i.Eq(Context, one).Ite(
Context,
BoxingFun.Apply(zero),
coercion);
return(coercion);
}
/// <summary>
/// Coerces an integer into a natural.
/// </summary>
public Z3Expr MkNatCoercion(Z3IntExpr i)
{
var zero = Context.MkInt(0);
var one = Context.MkInt(1);
var two = Context.MkInt(2);
var evenCase = BoxingFun.Apply(i.Neg(Context).Div(Context, two));
var coercion = i.IsEven(Context).Not(Context).Ite(
Context,
BoxingFun.Apply(i.Add(Context, one).Div(Context, two)),
evenCase);
coercion = i.Eq(Context, zero).Ite(
Context,
BoxingFun.Apply(zero),
coercion);
return(coercion);
}
public IntRangeEmbedding(TypeEmbedder owner, BigInteger lower, BigInteger upper)
{
Contract.Requires(owner != null);
Contract.Requires(lower <= upper);
Owner = owner;
Lower = lower;
Upper = upper;
var width = upper - lower + 1;
Contract.Assert(width > 1 && width.IsPowerOfTwo);
bvSort = Context.MkBitVecSort(width.MostSignificantOne());
bool wasAdded;
Type = Index.MkApply(Index.RangeSymbol,
new Term[]
{
Index.MkCnst(new Rational(lower, BigInteger.One), out wasAdded),
Index.MkCnst(new Rational(upper, BigInteger.One), out wasAdded)
},
out wasAdded);
boxingCon = Context.MkConstructor(
string.Format(BoxingName, lower, upper),
string.Format(TesterName, lower, upper),
new string[] { string.Format(UnboxingName, lower, upper) },
new Z3Sort[] { bvSort });
Representation = Context.MkDatatypeSort(string.Format(SortName, lower, upper), new Z3Con[] { boxingCon });
BoxingFun = boxingCon.ConstructorDecl;
UnboxingFun = boxingCon.AccessorDecls[0];
TesterFun = boxingCon.TesterDecl;
DefaultMember = new Tuple <Term, Z3Expr>(
Index.MkCnst(new Rational(lower, BigInteger.One), out wasAdded),
BoxingFun.Apply(Context.MkBV(0, bvSort.Size)));
z3Lower = Context.MkInt(Lower.ToString());
}
public static Z3BoolExpr IsEven(this Z3IntExpr expr1, Z3Context context)
{
Contract.Assert(expr1 != null);
return(context.MkEq(context.MkRem(expr1, context.MkInt(2)), context.MkInt(0)));
}
public static Z3ArithExpr Mod(this Z3IntExpr expr1, Z3Context context, Z3IntExpr expr2)
{
Contract.Requires(expr1 != null && expr2 != null);
return(context.MkMod(expr1, expr2));
}
