private Kind isPowerOfTwoOperation(Variable v, Expr expr)
{
if (!(
v.TypedIdent.Type.Equals(verifier.IntRep.GetIntType(8)) ||
v.TypedIdent.Type.Equals(verifier.IntRep.GetIntType(16)) ||
v.TypedIdent.Type.Equals(verifier.IntRep.GetIntType(32))
))
{
return(Kind.No);
}
Expr lhs, rhs;
if (IntegerRepresentationHelper.IsFun(expr, "MUL", out lhs, out rhs))
{
if ((IsVariable(lhs, v) || IsVariable(rhs, v)) && (IsConstant(lhs, 2) || IsConstant(rhs, 2)))
{
return(Kind.Inc);
}
}
if (IntegerRepresentationHelper.IsFun(expr, "DIV", out lhs, out rhs) ||
IntegerRepresentationHelper.IsFun(expr, "SDIV", out lhs, out rhs))
{
if (IsVariable(lhs, v) && IsConstant(rhs, 2))
{
return(Kind.Dec);
}
}
if (IntegerRepresentationHelper.IsFun(expr, "SHL", out lhs, out rhs))
{
if (IsVariable(lhs, v) && IsConstant(rhs, 1))
{
return(Kind.Inc);
}
}
if (IntegerRepresentationHelper.IsFun(expr, "ASHR", out lhs, out rhs))
{
if (IsVariable(lhs, v) && IsConstant(rhs, 1))
{
return(Kind.Dec);
}
}
if (IntegerRepresentationHelper.IsFun(expr, "LSHR", out lhs, out rhs))
{
if (IsVariable(lhs, v) && IsConstant(rhs, 1))
{
return(Kind.Dec);
}
}
return(Kind.No);
}
private Variable GetPowerOfTwoRhsVariable(Expr expr)
{
Expr lhs, rhs;
if (IntegerRepresentationHelper.IsFun(expr, "MUL", out lhs, out rhs))
{
if (IsVariable(lhs) && IsConstant(rhs, 2))
{
return(GetVariable(lhs));
}
else if (IsConstant(lhs, 2) && IsVariable(rhs))
{
return(GetVariable(rhs));
}
else
{
return(null);
}
}
if (IntegerRepresentationHelper.IsFun(expr, "DIV", out lhs, out rhs) ||
IntegerRepresentationHelper.IsFun(expr, "SDIV", out lhs, out rhs))
{
if (IsVariable(lhs) && IsConstant(rhs, 2))
{
return(GetVariable(lhs));
}
else
{
return(null);
}
}
if (IntegerRepresentationHelper.IsFun(expr, "SHL", out lhs, out rhs) ||
IntegerRepresentationHelper.IsFun(expr, "ASHR", out lhs, out rhs) ||
IntegerRepresentationHelper.IsFun(expr, "LSHR", out lhs, out rhs))
{
if (IsVariable(lhs) && IsConstant(rhs))
{
return(GetVariable(lhs));
}
else
{
return(null);
}
}
return(null);
}
public bool IsSext(Expr e, out Expr subExpr)
{
return(IntegerRepresentationHelper.IsFun(e, "SEXT[0-9]+", out subExpr));
}
public bool IsMul(Expr e, out Expr lhs, out Expr rhs)
{
return(IntegerRepresentationHelper.IsFun(e, "MUL", out lhs, out rhs));
}