bvt boolbvt::convert_power(const binary_exprt &expr)
{
const typet &type=ns.follow(expr.type());
std::size_t width=boolbv_width(type);
if(width==0)
return conversion_failed(expr);
if(type.id()==ID_unsignedbv ||
type.id()==ID_signedbv)
{
// Let's do the special case 2**x
bvt op0=convert_bv(expr.op0());
bvt op1=convert_bv(expr.op1());
literalt eq_2=
bv_utils.equal(op0, bv_utils.build_constant(2, op0.size()));
bvt one=bv_utils.build_constant(1, width);
bvt shift=bv_utils.shift(one, bv_utilst::LEFT, op1);
bvt nondet=prop.new_variables(width);
return bv_utils.select(eq_2, shift, nondet);
}
return conversion_failed(expr);
}
void boolbvt::convert_div(const exprt &expr, bvt &bv)
{
if(expr.type().id()!=ID_unsignedbv &&
expr.type().id()!=ID_signedbv &&
expr.type().id()!=ID_fixedbv)
return conversion_failed(expr, bv);
unsigned width=boolbv_width(expr.type());
if(width==0)
return conversion_failed(expr, bv);
if(expr.operands().size()!=2)
throw "division takes two operands";
if(expr.op0().type().id()!=expr.type().id() ||
expr.op1().type().id()!=expr.type().id())
return conversion_failed(expr, bv);
bvt op0=convert_bv(expr.op0());
bvt op1=convert_bv(expr.op1());
if(op0.size()!=width ||
op1.size()!=width)
throw "convert_div: unexpected operand width";
bvt res, rem;
if(expr.type().id()==ID_fixedbv)
{
unsigned fraction_bits=
to_fixedbv_type(expr.type()).get_fraction_bits();
bvt zeros;
zeros.resize(fraction_bits, const_literal(false));
// add fraction_bits least-significant bits
op0.insert(op0.begin(), zeros.begin(), zeros.end());
op1=bv_utils.sign_extension(op1, op1.size()+fraction_bits);
bv_utils.divider(op0, op1, res, rem, bv_utilst::SIGNED);
// cut it down again
res.resize(width);
}
else
{
bv_utilst::representationt rep=
expr.type().id()==ID_signedbv?bv_utilst::SIGNED:
bv_utilst::UNSIGNED;
bv_utils.divider(op0, op1, res, rem, rep);
}
bv=res;
}
bvt boolbvt::convert_array_of(const array_of_exprt &expr)
{
if(expr.type().id()!=ID_array)
throw "array_of must be array-typed";
const array_typet &array_type=to_array_type(expr.type());
if(is_unbounded_array(array_type))
return conversion_failed(expr);
std::size_t width=boolbv_width(array_type);
if(width==0)
{
// A zero-length array is acceptable;
// an element with unknown size is not.
if(boolbv_width(array_type.subtype())==0)
return conversion_failed(expr);
else
return bvt();
}
const exprt &array_size=array_type.size();
mp_integer size;
if(to_integer(array_size, size))
return conversion_failed(expr);
const bvt &tmp=convert_bv(expr.op0());
bvt bv;
bv.resize(width);
if(size*tmp.size()!=width)
throw "convert_array_of: unexpected operand width";
std::size_t offset=0;
for(mp_integer i=0; i<size; i=i+1)
{
for(std::size_t j=0; j<tmp.size(); j++, offset++)
bv[offset]=tmp[j];
}
assert(offset==bv.size());
return bv;
}
void boolbvt::convert_index(
const exprt &array,
const mp_integer &index,
bvt &bv)
{
const array_typet &array_type=
to_array_type(ns.follow(array.type()));
unsigned width=boolbv_width(array_type.subtype());
if(width==0)
return conversion_failed(array, bv);
bv.resize(width);
const bvt &tmp=convert_bv(array); // recursive call
mp_integer offset=index*width;
if(offset>=0 &&
offset+width<=mp_integer(tmp.size()))
{
// in bounds
for(unsigned i=0; i<width; i++)
bv[i]=tmp[integer2long(offset+i)];
}
else
{
// out of bounds
for(unsigned i=0; i<width; i++)
bv[i]=prop.new_variable();
}
}
void boolbvt::convert_concatenation(const exprt &expr, bvt &bv)
{
unsigned width=boolbv_width(expr.type());
if(width==0)
return conversion_failed(expr, bv);
const exprt::operandst &operands=expr.operands();
if(operands.size()==0)
throw "concatenation takes at least one operand";
unsigned offset=width;
bv.resize(width);
forall_expr(it, operands)
{
const bvt &op=convert_bv(*it);
if(op.size()>offset)
throw "concatenation operand width too big";
offset-=op.size();
for(unsigned i=0; i<op.size(); i++)
bv[offset+i]=op[i];
}
if(offset!=0)
throw "concatenation operand width too small";
}
bvt boolbvt::convert_array(const exprt &expr)
{
std::size_t width=boolbv_width(expr.type());
if(width==0)
return conversion_failed(expr);
if(expr.type().id()==ID_array)
{
assert(expr.has_operands());
const exprt::operandst &operands=expr.operands();
assert(!operands.empty());
std::size_t op_width=width/operands.size();
bvt bv;
bv.reserve(width);
forall_expr(it, operands)
{
const bvt &tmp=convert_bv(*it);
if(tmp.size()!=op_width)
throw "convert_array: unexpected operand width";
forall_literals(it2, tmp)
bv.push_back(*it2);
}
return bv;
}
void boolbvt::convert_replication(const exprt &expr, bvt &bv)
{
unsigned width=boolbv_width(expr.type());
if(width==0)
return conversion_failed(expr, bv);
if(expr.operands().size()!=2)
throw "replication takes two operands";
mp_integer times;
if(to_integer(expr.op0(), times))
throw "replication takes constant as first parameter";
const unsigned u_times=integer2unsigned(times);
const bvt &op=convert_bv(expr.op1());
unsigned offset=0;
bv.resize(width);
for(unsigned i=0; i<u_times; i++)
{
if(op.size()+offset>width)
throw "replication operand width too big";
for(unsigned i=0; i<op.size(); i++)
bv[i+offset]=op[i];
offset+=op.size();
}
if(offset!=bv.size())
throw "replication operand width too small";
}
void boolbvt::convert_constant(const constant_exprt &expr, bvt &bv)
{
unsigned width=boolbv_width(expr.type());
if(width==0)
return conversion_failed(expr, bv);
bv.resize(width);
const typet &expr_type=expr.type();
if(expr_type.id()==ID_array)
{
unsigned op_width=width/expr.operands().size();
unsigned offset=0;
forall_operands(it, expr)
{
const bvt &tmp=convert_bv(*it);
if(tmp.size()!=op_width)
throw "convert_constant: unexpected operand width";
for(unsigned j=0; j<op_width; j++)
bv[offset+j]=tmp[j];
offset+=op_width;
}
return;
}
void boolbvt::convert_cond(const exprt &expr, bvt &bv)
{
const exprt::operandst &operands=expr.operands();
unsigned width=boolbv_width(expr.type());
if(width==0)
return conversion_failed(expr, bv);
bv.resize(width);
// make it free variables
Forall_literals(it, bv)
*it=prop.new_variable();
if(operands.size()<2)
throw "cond takes at least two operands";
if((operands.size()%2)!=0)
throw "number of cond operands must be even";
if(prop.has_set_to())
{
bool condition=true;
literalt previous_cond=const_literal(false);
literalt cond_literal=const_literal(false);
forall_operands(it, expr)
{
if(condition)
{
cond_literal=convert(*it);
cond_literal=prop.land(prop.lnot(previous_cond), cond_literal);
previous_cond=prop.lor(previous_cond, cond_literal);
}
else
{
const bvt &op=convert_bv(*it);
if(bv.size()!=op.size())
{
std::cerr << "result size: " << bv.size()
<< std::endl
<< "operand: " << op.size() << std::endl
<< it->pretty()
<< std::endl;
throw "size of value operand does not match";
}
literalt value_literal=bv_utils.equal(bv, op);
prop.l_set_to_true(prop.limplies(cond_literal, value_literal));
}
condition=!condition;
}
}
void boolbvt::convert_floatbv_typecast(
const floatbv_typecast_exprt &expr, bvt &bv)
{
const exprt &op0=expr.op(); // number to convert
const exprt &op1=expr.rounding_mode(); // rounding mode
bvt bv0=convert_bv(op0);
bvt bv1=convert_bv(op1);
const typet &src_type=ns.follow(expr.op0().type());
const typet &dest_type=ns.follow(expr.type());
if(src_type==dest_type) // redundant type cast?
{
bv=bv0;
return;
}
float_utilst float_utils(prop);
float_utils.set_rounding_mode(convert_bv(op1));
if(src_type.id()==ID_floatbv &&
dest_type.id()==ID_floatbv)
{
float_utils.spec=to_floatbv_type(src_type);
bv=float_utils.conversion(bv0, to_floatbv_type(dest_type));
}
else if(src_type.id()==ID_signedbv &&
dest_type.id()==ID_floatbv)
{
float_utils.spec=to_floatbv_type(dest_type);
bv=float_utils.from_signed_integer(bv0);
}
else if(src_type.id()==ID_unsignedbv &&
dest_type.id()==ID_floatbv)
{
float_utils.spec=to_floatbv_type(dest_type);
bv=float_utils.from_unsigned_integer(bv0);
}
else if(src_type.id()==ID_floatbv &&
dest_type.id()==ID_signedbv)
{
std::size_t dest_width=to_signedbv_type(dest_type).get_width();
float_utils.spec=to_floatbv_type(src_type);
bv=float_utils.to_signed_integer(bv0, dest_width);
}
else if(src_type.id()==ID_floatbv &&
dest_type.id()==ID_unsignedbv)
{
std::size_t dest_width=to_unsignedbv_type(dest_type).get_width();
float_utils.spec=to_floatbv_type(src_type);
bv=float_utils.to_unsigned_integer(bv0, dest_width);
}
else
return conversion_failed(expr, bv);
}
void boolbvt::convert_shift(const exprt &expr, bvt &bv)
{
if(expr.type().id()!=ID_unsignedbv &&
expr.type().id()!=ID_signedbv)
return conversion_failed(expr, bv);
unsigned width=boolbv_width(expr.type());
if(width==0)
return conversion_failed(expr, bv);
if(width==0)
throw "zero length bit vector type: "+expr.type().to_string();
if(expr.operands().size()!=2)
throw "shifting takes two operands";
bvt op, dist;
convert_bv(expr.op0(), op);
convert_bv(expr.op1(), dist);
if(op.size()!=width)
throw "convert_shift: unexpected operand width";
bv_utilst::shiftt shift;
if(expr.id()==ID_shl)
shift=bv_utilst::LEFT;
else if(expr.id()==ID_ashr)
shift=bv_utilst::ARIGHT;
else if(expr.id()==ID_lshr)
shift=bv_utilst::LRIGHT;
else
throw "unexpected operand";
bv=bv_utils.shift(op, shift, dist);
}
bvt boolbvt::convert_bv_typecast(const typecast_exprt &expr)
{
const typet &expr_type=ns.follow(expr.type());
const exprt &op=expr.op();
const typet &op_type=ns.follow(op.type());
const bvt &op_bv=convert_bv(op);
bvt bv;
if(type_conversion(op_type, op_bv, expr_type, bv))
return conversion_failed(expr);
return bv;
}
void boolbvt::convert_shift(const exprt &expr, bvt &bv)
{
if(expr.type().id()!=ID_unsignedbv &&
expr.type().id()!=ID_signedbv &&
expr.type().id()!=ID_floatbv &&
expr.type().id()!=ID_pointer &&
expr.type().id()!=ID_bv)
return conversion_failed(expr, bv);
unsigned width=boolbv_width(expr.type());
if(width==0)
return conversion_failed(expr, bv);
if(expr.operands().size()!=2)
throw "shifting takes two operands";
const bvt &op=convert_bv(expr.op0());
const bvt &dist=convert_bv(expr.op1());
if(op.size()!=width)
throw "convert_shift: unexpected operand width";
bv_utilst::shiftt shift;
if(expr.id()==ID_shl)
shift=bv_utilst::LEFT;
else if(expr.id()==ID_ashr)
shift=bv_utilst::ARIGHT;
else if(expr.id()==ID_lshr)
shift=bv_utilst::LRIGHT;
else
throw "unexpected operand";
bv=bv_utils.shift(op, shift, dist);
}
bvt boolbvt::convert_abs(const exprt &expr)
{
std::size_t width=boolbv_width(expr.type());
if(width==0)
return conversion_failed(expr);
const exprt::operandst &operands=expr.operands();
if(operands.size()!=1)
throw "abs takes one operand";
const exprt &op0=expr.op0();
const bvt &op_bv=convert_bv(op0);
if(op0.type()!=expr.type())
return conversion_failed(expr);
bvtypet bvtype=get_bvtype(expr.type());
if(bvtype==IS_FIXED ||
bvtype==IS_SIGNED ||
bvtype==IS_UNSIGNED)
{
return bv_utils.absolute_value(op_bv);
}
else if(bvtype==IS_FLOAT)
{
float_utilst float_utils(prop);
float_utils.spec=to_floatbv_type(expr.type());
return float_utils.abs(op_bv);
}
return conversion_failed(expr);
}
bvt boolbvt::convert_with(const exprt &expr)
{
if(expr.operands().size()<3)
{
error().source_location=expr.find_source_location();
error() << "with takes at least three operands" << eom;
throw 0;
}
if((expr.operands().size()%2)!=1)
{
error().source_location=expr.find_source_location();
error() << "with takes an odd number of operands" << eom;
throw 0;
}
bvt bv=convert_bv(expr.op0());
std::size_t width=boolbv_width(expr.type());
if(width==0)
return conversion_failed(expr);
if(bv.size()!=width)
{
error().source_location=expr.find_source_location();
error() << "unexpected operand 0 width" << eom;
throw 0;
}
bvt prev_bv;
prev_bv.resize(width);
const exprt::operandst &ops=expr.operands();
for(std::size_t op_no=1; op_no<ops.size(); op_no+=2)
{
bv.swap(prev_bv);
convert_with(expr.op0().type(),
ops[op_no],
ops[op_no+1],
prev_bv,
bv);
}
return bv;
}
bvt boolbvt::convert_union(const union_exprt &expr)
{
std::size_t width=boolbv_width(expr.type());
if(width==0)
return conversion_failed(expr);
const bvt &op_bv=convert_bv(expr.op());
if(width<op_bv.size())
throw "union: unexpected operand op width";
bvt bv;
bv.resize(width);
if(config.ansi_c.endianness==configt::ansi_ct::endiannesst::IS_LITTLE_ENDIAN)
{
for(std::size_t i=0; i<op_bv.size(); i++)
bv[i]=op_bv[i];
// pad with nondets
for(std::size_t i=op_bv.size(); i<bv.size(); i++)
bv[i]=prop.new_variable();
}
else
{
assert(
config.ansi_c.endianness==configt::ansi_ct::endiannesst::IS_BIG_ENDIAN);
endianness_mapt map_u(expr.type(), false, ns);
endianness_mapt map_op(expr.op0().type(), false, ns);
for(std::size_t i=0; i<op_bv.size(); i++)
bv[map_u.map_bit(i)]=op_bv[map_op.map_bit(i)];
// pad with nondets
for(std::size_t i=op_bv.size(); i<bv.size(); i++)
bv[map_u.map_bit(i)]=prop.new_variable();
}
return bv;
}
void boolbvt::convert_update(const exprt &expr, bvt &bv)
{
const exprt::operandst &ops=expr.operands();
if(ops.size()!=3)
throw "update takes at three operands";
std::size_t width=boolbv_width(expr.type());
if(width==0)
return conversion_failed(expr, bv);
bv=convert_bv(ops[0]);
if(bv.size()!=width)
throw "update: unexpected operand 0 width";
// start the recursion
convert_update_rec(
expr.op1().operands(), 0, expr.type(), 0, expr.op2(), bv);
}
void boolbvt::convert_union(const exprt &expr, bvt &bv)
{
unsigned width=boolbv_width(expr.type());
if(width==0)
return conversion_failed(expr, bv);
if(expr.operands().size()!=1)
throw "union expects one argument";
const bvt &op_bv=convert_bv(expr.op0());
if(width<op_bv.size())
throw "union: unexpected operand op width";
bv.resize(width);
for(unsigned i=0; i<op_bv.size(); i++)
bv[i]=op_bv[i];
// pad with nondets
for(unsigned i=op_bv.size(); i<bv.size(); i++)
bv[i]=prop.new_variable();
}
void boolbvt::convert_mult(const exprt &expr, bvt &bv)
{
unsigned width=boolbv_width(expr.type());
if(width==0)
return conversion_failed(expr, bv);
bv.resize(width);
const exprt::operandst &operands=expr.operands();
if(operands.size()==0)
throw "mult without operands";
const exprt &op0=expr.op0();
bool no_overflow=expr.id()=="no-overflow-mult";
if(expr.type().id()==ID_fixedbv)
{
if(op0.type()!=expr.type())
throw "multiplication with mixed types";
bv=convert_bv(op0);
if(bv.size()!=width)
throw "convert_mult: unexpected operand width";
unsigned fraction_bits=
to_fixedbv_type(expr.type()).get_fraction_bits();
// do a sign extension by fraction_bits bits
bv=bv_utils.sign_extension(bv, bv.size()+fraction_bits);
for(exprt::operandst::const_iterator it=operands.begin()+1;
it!=operands.end(); it++)
{
if(it->type()!=expr.type())
throw "multiplication with mixed types";
bvt op=convert_bv(*it);
if(op.size()!=width)
throw "convert_mult: unexpected operand width";
op=bv_utils.sign_extension(op, bv.size());
bv=bv_utils.signed_multiplier(bv, op);
}
// cut it down again
bv.erase(bv.begin(), bv.begin()+fraction_bits);
return;
}
else if(expr.type().id()==ID_floatbv)
{
if(op0.type()!=expr.type())
throw "multiplication with mixed types";
bv=convert_bv(op0);
if(bv.size()!=width)
throw "convert_mult: unexpected operand width";
float_utilst float_utils(prop);
float_utils.spec=to_floatbv_type(expr.type());
for(exprt::operandst::const_iterator it=operands.begin()+1;
it!=operands.end(); it++)
{
if(it->type()!=expr.type())
throw "multiplication with mixed types";
const bvt &op=convert_bv(*it);
if(op.size()!=width)
throw "convert_mult: unexpected operand width";
bv=float_utils.mul(bv, op);
}
return;
}
else if(expr.type().id()==ID_unsignedbv ||
expr.type().id()==ID_signedbv)
{
if(op0.type()!=expr.type())
throw "multiplication with mixed types";
bv_utilst::representationt rep=
expr.type().id()==ID_signedbv?bv_utilst::SIGNED:
bv_utilst::UNSIGNED;
bv=convert_bv(op0);
if(bv.size()!=width)
throw "convert_mult: unexpected operand width";
for(exprt::operandst::const_iterator it=operands.begin()+1;
it!=operands.end(); it++)
{
if(it->type()!=expr.type())
throw "multiplication with mixed types";
const bvt &op=convert_bv(*it);
if(op.size()!=width)
throw "convert_mult: unexpected operand width";
if(no_overflow)
bv=bv_utils.multiplier_no_overflow(bv, op, rep);
else
bv=bv_utils.multiplier(bv, op, rep);
}
return;
}
conversion_failed(expr, bv);
}
void boolbvt::convert_index(const index_exprt &expr, bvt &bv)
{
if(expr.id()!=ID_index)
throw "expected index expression";
if(expr.operands().size()!=2)
throw "index takes two operands";
const exprt &array=expr.array();
const exprt &index=expr.index();
const array_typet &array_type=
to_array_type(ns.follow(array.type()));
// see if the array size is constant
if(is_unbounded_array(array_type))
{
// use array decision procedure
unsigned width=boolbv_width(expr.type());
if(width==0)
return conversion_failed(expr, bv);
// free variables
bv.resize(width);
for(unsigned i=0; i<width; i++)
bv[i]=prop.new_variable();
record_array_index(expr);
// record type if array is a symbol
if(array.id()==ID_symbol)
map.get_map_entry(
to_symbol_expr(array).get_identifier(), array_type);
// make sure we have the index in the cache
convert_bv(index);
return;
}
// see if the index address is constant
mp_integer index_value;
if(!to_integer(index, index_value))
return convert_index(array, index_value, bv);
unsigned width=boolbv_width(expr.type());
if(width==0)
return conversion_failed(expr, bv);
mp_integer array_size;
if(to_integer(array_type.size(), array_size))
{
std::cout << to_array_type(array.type()).size().pretty() << std::endl;
throw "failed to convert array size";
}
// get literals for the whole array
const bvt &array_bv=convert_bv(array);
if(array_size*width!=array_bv.size())
throw "unexpected array size";
// TODO: maybe a shifter-like construction would be better
if(prop.has_set_to())
{
// free variables
bv.resize(width);
for(unsigned i=0; i<width; i++)
bv[i]=prop.new_variable();
// add implications
equal_exprt index_equality;
index_equality.lhs()=index; // index operand
bvt equal_bv;
equal_bv.resize(width);
for(mp_integer i=0; i<array_size; i=i+1)
{
index_equality.rhs()=from_integer(i, index_equality.lhs().type());
if(index_equality.rhs().is_nil())
throw "number conversion failed (1)";
mp_integer offset=i*width;
for(unsigned j=0; j<width; j++)
equal_bv[j]=prop.lequal(bv[j],
array_bv[integer2long(offset+j)]);
prop.l_set_to_true(
prop.limplies(convert(index_equality), prop.land(equal_bv)));
}
}
else
{
bv.resize(width);
equal_exprt equality;
equality.lhs()=index; // index operand
typet constant_type=index.type(); // type of index operand
assert(array_size>0);
for(mp_integer i=0; i<array_size; i=i+1)
{
equality.op1()=from_integer(i, constant_type);
literalt e=convert(equality);
mp_integer offset=i*width;
for(unsigned j=0; j<width; j++)
{
literalt l=array_bv[integer2long(offset+j)];
if(i==0) // this initializes bv
bv[j]=l;
else
bv[j]=prop.lselect(e, l, bv[j]);
}
}
}
}
void boolbvt::convert_add_sub(const exprt &expr, bvt &bv)
{
const typet &type=ns.follow(expr.type());
if(type.id()!=ID_unsignedbv &&
type.id()!=ID_signedbv &&
type.id()!=ID_fixedbv &&
type.id()!=ID_floatbv &&
type.id()!=ID_range &&
type.id()!=ID_vector)
return conversion_failed(expr, bv);
unsigned width=boolbv_width(type);
if(width==0)
return conversion_failed(expr, bv);
const exprt::operandst &operands=expr.operands();
if(operands.size()==0)
throw "operand "+expr.id_string()+" takes at least one operand";
const exprt &op0=expr.op0();
if(op0.type()!=type)
{
std::cerr << expr.pretty() << std::endl;
throw "add/sub with mixed types";
}
convert_bv(op0, bv);
if(bv.size()!=width)
throw "convert_add_sub: unexpected operand 0 width";
bool subtract=(expr.id()==ID_minus ||
expr.id()=="no-overflow-minus");
bool no_overflow=(expr.id()=="no-overflow-plus" ||
expr.id()=="no-overflow-minus");
typet arithmetic_type=
(type.id()==ID_vector)?ns.follow(type.subtype()):type;
bv_utilst::representationt rep=
(arithmetic_type.id()==ID_signedbv ||
arithmetic_type.id()==ID_fixedbv)?bv_utilst::SIGNED:
bv_utilst::UNSIGNED;
for(exprt::operandst::const_iterator
it=operands.begin()+1;
it!=operands.end(); it++)
{
if(it->type()!=type)
{
std::cerr << expr.pretty() << std::endl;
throw "add/sub with mixed types";
}
bvt op;
convert_bv(*it, op);
if(op.size()!=width)
throw "convert_add_sub: unexpected operand width";
if(type.id()==ID_vector)
{
const typet &subtype=ns.follow(type.subtype());
unsigned sub_width=boolbv_width(subtype);
if(sub_width==0 || width%sub_width!=0)
throw "convert_add_sub: 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.size());
tmp_op[j]=op[i*sub_width+j];
}
bvt tmp_result;
tmp_result.resize(sub_width);
for(unsigned j=0; j<tmp_result.size(); j++)
{
assert(i*sub_width+j<bv.size());
tmp_result[j]=bv[i*sub_width+j];
}
if(type.subtype().id()==ID_floatbv)
{
#ifdef HAVE_FLOATBV
float_utilst float_utils(prop);
float_utils.spec=to_floatbv_type(subtype);
tmp_result=float_utils.add_sub(tmp_result, tmp_op, subtract);
#else
return conversion_failed(expr, bv);
#endif
}
else
tmp_result=bv_utils.add_sub(tmp_result, tmp_op, subtract);
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];
}
}
}
else if(type.id()==ID_floatbv)
{
#ifdef HAVE_FLOATBV
float_utilst float_utils(prop);
float_utils.spec=to_floatbv_type(arithmetic_type);
bv=float_utils.add_sub(bv, op, subtract);
#else
return conversion_failed(expr, bv);
#endif
}
else if(no_overflow)
bv=bv_utils.add_sub_no_overflow(bv, op, subtract, rep);
else
bv=bv_utils.add_sub(bv, op, subtract);
}
}
void boolbvt::convert_constraint_select_one(const exprt &expr, bvt &bv)
{
const exprt::operandst &operands=expr.operands();
if(expr.id()!="constraint_select_one")
throw "expected constraint_select_one expression";
if(operands.size()<2)
throw "constraint_select_one takes at least two operands";
if(expr.type()!=expr.op0().type())
throw "constraint_select_one expects matching types";
if(prop.has_set_to())
{
std::vector<bvt> op_bv;
op_bv.reserve(expr.operands().size());
forall_operands(it, expr)
op_bv.push_back(convert_bv(*it));
bv=op_bv[0];
// add constraints
bvt equal_bv;
equal_bv.resize(bv.size());
bvt b;
b.reserve(op_bv.size()-1);
for(unsigned i=1; i<op_bv.size(); i++)
{
if(op_bv[i].size()!=bv.size())
throw "constraint_select_one expects matching width";
for(unsigned j=0; j<bv.size(); j++)
equal_bv[j]=prop.lequal(bv[j], op_bv[i][j]);
b.push_back(prop.land(equal_bv));
}
prop.l_set_to_true(prop.lor(b));
}
else
{
unsigned op_nr=0;
forall_operands(it, expr)
{
const bvt &op_bv=convert_bv(*it);
if(op_nr==0)
bv=op_bv;
else
{
if(op_bv.size()!=bv.size())
return conversion_failed(expr, bv);
for(unsigned i=0; i<op_bv.size(); i++)
bv[i]=prop.lselect(prop.new_variable(), bv[i], op_bv[i]);
}
op_nr++;
}
}
}
void boolbvt::convert_unary_minus(const 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);
}
bvt boolbvt::convert_extractbits(const extractbits_exprt &expr)
{
std::size_t width=boolbv_width(expr.type());
if(width==0)
return conversion_failed(expr);
const irep_idt &type_id=expr.type().id();
if(type_id!=ID_signedbv &&
type_id!=ID_unsignedbv &&
type_id!=ID_c_enum &&
type_id!=ID_c_enum_tag &&
type_id!=ID_bv)
return conversion_failed(expr);
if(expr.operands().size()!=3)
{
error().source_location=expr.find_source_location();
error() << "extractbits takes three operands" << eom;
throw 0;
}
mp_integer o1, o2;
const bvt &bv0=convert_bv(expr.op0());
// We only do constants for now.
// Should implement a shift here.
if(to_integer(expr.op1(), o1) ||
to_integer(expr.op2(), o2))
return conversion_failed(expr);
if(o1<0 || o1>=bv0.size())
{
error().source_location=expr.find_source_location();
error() << "extractbits: second operand out of range: "
<< expr.pretty() << eom;
}
if(o2<0 || o2>=bv0.size())
{
error().source_location=expr.find_source_location();
error() << "extractbits: third operand out of range: "
<< expr.pretty() << eom;
throw 0;
}
if(o2>o1)
std::swap(o1, o2);
// now o2<=o1
if((o1-o2+1)!=width)
{
error().source_location=expr.find_source_location();
error() << "extractbits: wrong width (expected " << (o1-o2+1)
<< " but got " << width << "): " << expr.pretty() << eom;
throw 0;
}
std::size_t offset=integer2unsigned(o2);
bvt bv;
bv.resize(width);
for(std::size_t i=0; i<width; i++)
bv[i]=bv0[offset+i];
return bv;
}
void boolbvt::convert_floatbv_op(const exprt &expr, bvt &bv)
{
const exprt::operandst &operands=expr.operands();
if(operands.size()!=3)
throw "operator "+expr.id_string()+" takes three operands";
const exprt &op0=expr.op0(); // first operand
const exprt &op1=expr.op1(); // second operand
const exprt &op2=expr.op2(); // rounding mode
bvt bv0=convert_bv(op0);
bvt bv1=convert_bv(op1);
bvt bv2=convert_bv(op2);
const typet &type=ns.follow(expr.type());
if(op0.type()!=type || op1.type()!=type)
{
std::cerr << expr.pretty() << std::endl;
throw "float op with mixed types";
}
float_utilst float_utils(prop);
float_utils.set_rounding_mode(bv2);
if(type.id()==ID_floatbv)
{
float_utils.spec=to_floatbv_type(expr.type());
if(expr.id()==ID_floatbv_plus)
bv=float_utils.add_sub(bv0, bv1, false);
else if(expr.id()==ID_floatbv_minus)
bv=float_utils.add_sub(bv0, bv1, true);
else if(expr.id()==ID_floatbv_mult)
bv=float_utils.mul(bv0, bv1);
else if(expr.id()==ID_floatbv_div)
bv=float_utils.div(bv0, bv1);
else if(expr.id()==ID_floatbv_rem)
bv=float_utils.rem(bv0, bv1);
else
assert(false);
}
else if(type.id()==ID_vector || type.id()==ID_complex)
{
const typet &subtype=ns.follow(type.subtype());
if(subtype.id()==ID_floatbv)
{
float_utils.spec=to_floatbv_type(subtype);
std::size_t width=boolbv_width(type);
std::size_t sub_width=boolbv_width(subtype);
if(sub_width==0 || width%sub_width!=0)
throw "convert_floatbv_op: unexpected vector operand width";
std::size_t size=width/sub_width;
bv.resize(width);
for(std::size_t i=0; i<size; i++)
{
bvt tmp_bv0, tmp_bv1, tmp_bv;
tmp_bv0.assign(bv0.begin()+i*sub_width, bv0.begin()+(i+1)*sub_width);
tmp_bv1.assign(bv1.begin()+i*sub_width, bv1.begin()+(i+1)*sub_width);
if(expr.id()==ID_floatbv_plus)
tmp_bv=float_utils.add_sub(tmp_bv0, tmp_bv1, false);
else if(expr.id()==ID_floatbv_minus)
tmp_bv=float_utils.add_sub(tmp_bv0, tmp_bv1, true);
else if(expr.id()==ID_floatbv_mult)
tmp_bv=float_utils.mul(tmp_bv0, tmp_bv1);
else if(expr.id()==ID_floatbv_div)
tmp_bv=float_utils.div(tmp_bv0, tmp_bv1);
else
assert(false);
assert(tmp_bv.size()==sub_width);
assert(i*sub_width+sub_width-1<bv.size());
std::copy(tmp_bv.begin(), tmp_bv.end(), bv.begin()+i*sub_width);
}
}
else
return conversion_failed(expr, bv);
}
else
return conversion_failed(expr, bv);
}
void boolbvt::convert_bitwise(const exprt &expr, bvt &bv)
{
unsigned width=boolbv_width(expr.type());
if(width==0)
return conversion_failed(expr, bv);
if(expr.id()==ID_bitnot)
{
if(expr.operands().size()!=1)
throw "bitnot takes one operand";
const exprt &op0=expr.op0();
const bvt &op_bv=convert_bv(op0);
if(op_bv.size()!=width)
throw "convert_bitwise: unexpected operand width";
bv=bv_utils.inverted(op_bv);
return;
}
else if(expr.id()==ID_bitand || expr.id()==ID_bitor ||
expr.id()==ID_bitxor ||
expr.id()==ID_bitnand || expr.id()==ID_bitnor ||
expr.id()==ID_bitxnor)
{
bv.resize(width);
forall_operands(it, expr)
{
const bvt &op=convert_bv(*it);
if(op.size()!=width)
throw "convert_bitwise: unexpected operand width";
if(it==expr.operands().begin())
bv=op;
else
{
for(unsigned i=0; i<width; i++)
{
if(expr.id()==ID_bitand)
bv[i]=prop.land(bv[i], op[i]);
else if(expr.id()==ID_bitor)
bv[i]=prop.lor(bv[i], op[i]);
else if(expr.id()==ID_bitxor)
bv[i]=prop.lxor(bv[i], op[i]);
else if(expr.id()==ID_bitnand)
bv[i]=prop.lnand(bv[i], op[i]);
else if(expr.id()==ID_bitnor)
bv[i]=prop.lnor(bv[i], op[i]);
else if(expr.id()==ID_bitxnor)
bv[i]=prop.lequal(bv[i], op[i]);
else
throw "unexpected operand";
}
}
}
return;
}
void boolbvt::convert_case(const exprt &expr, bvt &bv)
{
const std::vector<exprt> &operands=expr.operands();
unsigned width=boolbv_width(expr.type());
if(width==0)
return conversion_failed(expr, bv);
bv.resize(width);
// make it free variables
Forall_literals(it, bv)
*it=prop.new_variable();
if(operands.size()<3)
throw "case takes at least three operands";
if((operands.size()%2)!=1)
throw "number of case operands must be odd";
enum { FIRST, COMPARE, VALUE } what=FIRST;
bvt compare_bv;
literalt previous_compare=const_literal(false);
literalt compare_literal=const_literal(false);
forall_operands(it, expr)
{
bvt op=convert_bv(*it);
switch(what)
{
case FIRST:
compare_bv.swap(op);
what=COMPARE;
break;
case COMPARE:
if(compare_bv.size()!=op.size())
{
std::cerr << "compare operand: " << compare_bv.size()
<< std::endl
<< "operand: " << op.size() << std::endl
<< it->pretty()
<< std::endl;
throw "size of compare operand does not match";
}
compare_literal=bv_utils.equal(compare_bv, op);
compare_literal=prop.land(prop.lnot(previous_compare),
compare_literal);
previous_compare=prop.lor(previous_compare, compare_literal);
what=VALUE;
break;
case VALUE:
if(bv.size()!=op.size())
{
std::cerr << "result size: " << bv.size()
<< std::endl
<< "operand: " << op.size() << std::endl
<< it->pretty()
<< std::endl;
throw "size of value operand does not match";
}
{
literalt value_literal=bv_utils.equal(bv, op);
prop.l_set_to_true(
prop.limplies(compare_literal, value_literal));
}
what=COMPARE;
break;
default:
assert(false);
}
}
bvt boolbvt::convert_shift(const binary_exprt &expr)
{
const irep_idt &type_id=expr.type().id();
if(type_id!=ID_unsignedbv &&
type_id!=ID_signedbv &&
type_id!=ID_floatbv &&
type_id!=ID_pointer &&
type_id!=ID_bv &&
type_id!=ID_verilog_signedbv &&
type_id!=ID_verilog_unsignedbv)
return conversion_failed(expr);
std::size_t width=boolbv_width(expr.type());
if(width==0)
return conversion_failed(expr);
if(expr.operands().size()!=2)
throw "shifting takes two operands";
const bvt &op=convert_bv(expr.op0());
if(op.size()!=width)
throw "convert_shift: unexpected operand 0 width";
bv_utilst::shiftt shift;
if(expr.id()==ID_shl)
shift=bv_utilst::shiftt::LEFT;
else if(expr.id()==ID_ashr)
shift=bv_utilst::shiftt::ARIGHT;
else if(expr.id()==ID_lshr)
shift=bv_utilst::shiftt::LRIGHT;
else
throw "unexpected shift operator";
// we allow a constant as shift distance
if(expr.op1().is_constant())
{
mp_integer i;
if(to_integer(expr.op1(), i))
throw "convert_shift: failed to convert constant";
std::size_t distance;
if(i<0 || i>std::numeric_limits<signed>::max())
distance=0;
else
distance=integer2size_t(i);
if(type_id==ID_verilog_signedbv ||
type_id==ID_verilog_unsignedbv)
distance*=2;
return bv_utils.shift(op, shift, distance);
}
else
{
const bvt &distance=convert_bv(expr.op1());
return bv_utils.shift(op, shift, distance);
}
}