literalt boolbvt::convert_onehot(const unary_exprt &expr)
{
bvt op=convert_bv(expr.op());
literalt one_seen=const_literal(false);
literalt more_than_one_seen=const_literal(false);
for(bvt::const_iterator it=op.begin(); it!=op.end(); it++)
{
more_than_one_seen=
prop.lor(more_than_one_seen, prop.land(*it, one_seen));
one_seen=prop.lor(*it, one_seen);
}
if(expr.id()==ID_onehot)
return prop.land(one_seen, !more_than_one_seen);
else if(expr.id()==ID_onehot0)
return !more_than_one_seen;
else
throw "unexpected onehot expression";
}
void boolbvt::convert_unary_minus(const unary_exprt &expr, bvt &bv)
{
const typet &type=ns.follow(expr.type());
unsigned width=boolbv_width(type);
if(width==0)
return conversion_failed(expr, bv);
const exprt::operandst &operands=expr.operands();
if(operands.size()!=1)
throw "unary minus takes one operand";
const exprt &op0=expr.op0();
const bvt &op_bv=convert_bv(op0);
bvtypet bvtype=get_bvtype(type);
bvtypet op_bvtype=get_bvtype(op0.type());
unsigned op_width=op_bv.size();
bool no_overflow=(expr.id()=="no-overflow-unary-minus");
if(op_width==0 || op_width!=width)
return conversion_failed(expr, bv);
if(bvtype==IS_UNKNOWN &&
(type.id()==ID_vector || type.id()==ID_complex))
{
const typet &subtype=ns.follow(type.subtype());
unsigned sub_width=boolbv_width(subtype);
if(sub_width==0 || width%sub_width!=0)
throw "unary-: unexpected vector operand width";
unsigned size=width/sub_width;
bv.resize(width);
for(unsigned i=0; i<size; i++)
{
bvt tmp_op;
tmp_op.resize(sub_width);
for(unsigned j=0; j<tmp_op.size(); j++)
{
assert(i*sub_width+j<op_bv.size());
tmp_op[j]=op_bv[i*sub_width+j];
}
bvt tmp_result;
if(type.subtype().id()==ID_floatbv)
{
float_utilst float_utils(prop);
float_utils.spec=to_floatbv_type(subtype);
tmp_result=float_utils.negate(tmp_op);
}
else
tmp_result=bv_utils.negate(tmp_op);
assert(tmp_result.size()==sub_width);
for(unsigned j=0; j<tmp_result.size(); j++)
{
assert(i*sub_width+j<bv.size());
bv[i*sub_width+j]=tmp_result[j];
}
}
return;
}
else if(bvtype==IS_FIXED && op_bvtype==IS_FIXED)
{
if(no_overflow)
bv=bv_utils.negate_no_overflow(op_bv);
else
bv=bv_utils.negate(op_bv);
return;
}
else if(bvtype==IS_FLOAT && op_bvtype==IS_FLOAT)
{
assert(!no_overflow);
float_utilst float_utils(prop);
float_utils.spec=to_floatbv_type(expr.type());
bv=float_utils.negate(op_bv);
return;
}
else if((op_bvtype==IS_SIGNED || op_bvtype==IS_UNSIGNED) &&
(bvtype==IS_SIGNED || bvtype==IS_UNSIGNED))
{
if(no_overflow)
prop.l_set_to(bv_utils.overflow_negate(op_bv), false);
if(no_overflow)
bv=bv_utils.negate_no_overflow(op_bv);
else
bv=bv_utils.negate(op_bv);
return;
}
conversion_failed(expr, bv);
}
