c_typecastt::c_typet c_typecastt::minimum_promotion(
const typet &type) const
{
c_typet c_type=get_c_type(type);
// 6.3.1.1, par 2
// "If an int can represent all values of the original type, the
// value is converted to an int; otherwise, it is converted to
// an unsigned int."
c_typet max_type=std::max(c_type, INT); // minimum promotion
// The second case can arise if we promote any unsigned type
// that is as large as unsigned int.
if(config.ansi_c.short_int_width==config.ansi_c.int_width &&
max_type==USHORT)
max_type=UINT;
else if(config.ansi_c.char_width==config.ansi_c.int_width &&
max_type==UCHAR)
max_type=UINT;
else
max_type=std::max(max_type, INT);
if(max_type==UINT &&
type.id()==ID_c_bit_field &&
to_c_bit_field_type(type).get_width()<config.ansi_c.int_width)
max_type=INT;
return max_type;
}
void c_typecastt::implicit_typecast_arithmetic(
exprt &expr1,
exprt &expr2)
{
const typet &type1=ns.follow(expr1.type());
const typet &type2=ns.follow(expr2.type());
c_typet c_type1=get_c_type(type1),
c_type2=get_c_type(type2);
c_typet max_type=std::max(c_type1, c_type2);
// "If an int can represent all values of the original type, the
// value is converted to an int; otherwise, it is converted to
// an unsigned int."
// The second case can arise if we promote any unsigned type
// that is as large as unsigned int.
if(config.ansi_c.short_int_width==config.ansi_c.int_width &&
max_type==USHORT)
max_type=UINT;
else if(config.ansi_c.char_width==config.ansi_c.int_width &&
max_type==UCHAR)
max_type=UINT;
else
max_type=std::max(max_type, INT);
if(max_type==LARGE_SIGNED_INT || max_type==LARGE_UNSIGNED_INT)
{
// get the biggest width of both
unsigned width1=type1.get_int(ID_width);
unsigned width2=type2.get_int(ID_width);
// produce type
typet result_type;
if(width1==width2)
{
if(max_type==LARGE_SIGNED_INT)
result_type=signedbv_typet(width1);
else
result_type=unsignedbv_typet(width1);
}
else if(width1>width2)
result_type=type1;
else // width1<width2
result_type=type2;
do_typecast(expr1, result_type);
do_typecast(expr2, result_type);
return;
}
else if(max_type==COMPLEX)
{
if(c_type1==COMPLEX && c_type2==COMPLEX)
{
// promote to the one with bigger subtype
if(get_c_type(type1.subtype())>get_c_type(type2.subtype()))
do_typecast(expr2, type1);
else
do_typecast(expr1, type2);
}
else if(c_type1==COMPLEX)
{
assert(c_type1==COMPLEX && c_type2!=COMPLEX);
do_typecast(expr2, type1.subtype());
do_typecast(expr2, type1);
}
else
{
assert(c_type1!=COMPLEX && c_type2==COMPLEX);
do_typecast(expr1, type2.subtype());
do_typecast(expr1, type2);
}
return;
}
implicit_typecast_arithmetic(expr1, max_type);
implicit_typecast_arithmetic(expr2, max_type);
if(max_type==PTR)
{
if(c_type1==VOIDPTR)
do_typecast(expr1, expr2.type());
if(c_type2==VOIDPTR)
do_typecast(expr2, expr1.type());
}
}
void c_typecastt::implicit_typecast_arithmetic(exprt &expr)
{
c_typet c_type=get_c_type(expr.type());
c_type=std::max(c_type, INT); // minimum promotion
implicit_typecast_arithmetic(expr, c_type);
}
c_typecastt::c_typet c_typecastt::get_c_type(
const typet &type)
{
unsigned width=type.get_int(ID_width);
if(type.id()==ID_signedbv)
{
if(width<=config.ansi_c.char_width)
return CHAR;
else if(width<=config.ansi_c.short_int_width)
return SHORT;
else if(width<=config.ansi_c.int_width)
return INT;
else if(width<=config.ansi_c.long_int_width)
return LONG;
else if(width<=config.ansi_c.long_long_int_width)
return LONGLONG;
else
return LARGE_SIGNED_INT;
}
else if(type.id()==ID_unsignedbv)
{
if(type.get(ID_C_c_type)==ID_bool)
return BOOL;
if(width<=config.ansi_c.char_width)
return UCHAR;
else if(width<=config.ansi_c.short_int_width)
return USHORT;
else if(width<=config.ansi_c.int_width)
return UINT;
else if(width<=config.ansi_c.long_int_width)
return ULONG;
else if(width<=config.ansi_c.long_long_int_width)
return ULONGLONG;
else
return LARGE_UNSIGNED_INT;
}
else if(type.id()==ID_bool)
return BOOL;
else if(type.id()==ID_floatbv ||
type.id()==ID_fixedbv)
{
if(width<=config.ansi_c.single_width)
return SINGLE;
else if(width<=config.ansi_c.double_width)
return DOUBLE;
else if(width<=config.ansi_c.long_double_width)
return LONGDOUBLE;
}
else if(type.id()==ID_pointer)
{
if(type.subtype().id()==ID_empty)
return VOIDPTR;
else
return PTR;
}
else if(type.id()==ID_array)
{
return PTR;
}
else if(type.id()==ID_c_enum ||
type.id()==ID_incomplete_c_enum)
{
return INT;
}
else if(type.id()==ID_symbol)
return get_c_type(ns.follow(type));
else if(type.id()==ID_rational)
return RATIONAL;
else if(type.id()==ID_real)
return REAL;
else if(type.id()==ID_complex)
return COMPLEX;
return OTHER;
}
void c_typecastt::implicit_typecast_arithmetic(
exprt &expr1,
exprt &expr2)
{
const typet &type1=ns.follow(expr1.type());
const typet &type2=ns.follow(expr2.type());
c_typet c_type1=minimum_promotion(type1),
c_type2=minimum_promotion(type2);
c_typet max_type=std::max(c_type1, c_type2);
if(max_type==LARGE_SIGNED_INT || max_type==LARGE_UNSIGNED_INT)
{
// get the biggest width of both
unsigned width1=type1.get_int(ID_width);
unsigned width2=type2.get_int(ID_width);
// produce type
typet result_type;
if(width1==width2)
{
if(max_type==LARGE_SIGNED_INT)
result_type=signedbv_typet(width1);
else
result_type=unsignedbv_typet(width1);
}
else if(width1>width2)
result_type=type1;
else // width1<width2
result_type=type2;
do_typecast(expr1, result_type);
do_typecast(expr2, result_type);
return;
}
else if(max_type==COMPLEX)
{
if(c_type1==COMPLEX && c_type2==COMPLEX)
{
// promote to the one with bigger subtype
if(get_c_type(type1.subtype())>get_c_type(type2.subtype()))
do_typecast(expr2, type1);
else
do_typecast(expr1, type2);
}
else if(c_type1==COMPLEX)
{
assert(c_type1==COMPLEX && c_type2!=COMPLEX);
do_typecast(expr2, type1.subtype());
do_typecast(expr2, type1);
}
else
{
assert(c_type1!=COMPLEX && c_type2==COMPLEX);
do_typecast(expr1, type2.subtype());
do_typecast(expr1, type2);
}
return;
}
else if(max_type==SINGLE || max_type==DOUBLE ||
max_type==LONGDOUBLE || max_type==FLOAT128)
{
// Special-case optimisation:
// If we have two non-standard sized floats, don't do implicit type
// promotion if we can possibly avoid it.
if(type1==type2)
return;
}
implicit_typecast_arithmetic(expr1, max_type);
implicit_typecast_arithmetic(expr2, max_type);
if(max_type==PTR)
{
if(c_type1==VOIDPTR)
do_typecast(expr1, expr2.type());
if(c_type2==VOIDPTR)
do_typecast(expr2, expr1.type());
}
}
