exprt dereferencet::dereference_if(
const if_exprt &expr,
const exprt &offset,
const typet &type)
{
// push down the if, do recursive call
exprt true_case=dereference_rec(expr.true_case(), offset, type);
exprt false_case=dereference_rec(expr.false_case(), offset, type);
return if_exprt(expr.cond(), true_case, false_case);
}
bvt boolbvt::convert_if(const if_exprt &expr)
{
std::size_t width=boolbv_width(expr.type());
if(width==0)
return bvt(); // An empty bit-vector if.
literalt cond=convert(expr.cond());
const bvt &op1_bv=convert_bv(expr.true_case());
const bvt &op2_bv=convert_bv(expr.false_case());
if(op1_bv.size()!=width || op2_bv.size()!=width)
throw "operand size mismatch for if "+expr.pretty();
return bv_utils.select(cond, op1_bv, op2_bv);
}
void rd_range_domaint::assign_if(
const namespacet &ns,
locationt from,
const if_exprt &if_expr,
const mp_integer &size)
{
if(if_expr.cond().is_false())
assign(ns, from, if_expr.false_case(), size);
else if(if_expr.cond().is_true())
assign(ns, from, if_expr.true_case(), size);
else
{
rd_range_domaint false_case(*this);
assign(ns, from, if_expr.false_case(), size);
values.swap(false_case.values);
assign(ns, from, if_expr.true_case(), size);
merge(false_case, from);
}
}
void goto_convertt::do_function_call_if(
const exprt &lhs,
const if_exprt &function,
const exprt::operandst &arguments,
goto_programt &dest)
{
// case split
// c?f():g()
//--------------------
// v: if(!c) goto y;
// w: f();
// x: goto z;
// y: g();
// z: ;
// do the v label
goto_programt tmp_v;
goto_programt::targett v=tmp_v.add_instruction();
// do the x label
goto_programt tmp_x;
goto_programt::targett x=tmp_x.add_instruction();
// do the z label
goto_programt tmp_z;
goto_programt::targett z=tmp_z.add_instruction();
z->make_skip();
// y: g();
goto_programt tmp_y;
goto_programt::targett y;
do_function_call(lhs, function.false_case(), arguments, tmp_y);
if(tmp_y.instructions.empty())
y=tmp_y.add_instruction(SKIP);
else
y=tmp_y.instructions.begin();
// v: if(!c) goto y;
v->make_goto(y);
v->guard=function.cond();
v->guard.make_not();
v->source_location=function.cond().source_location();
// w: f();
goto_programt tmp_w;
do_function_call(lhs, function.true_case(), arguments, tmp_w);
if(tmp_w.instructions.empty())
tmp_w.add_instruction(SKIP);
// x: goto z;
x->make_goto(z);
dest.destructive_append(tmp_v);
dest.destructive_append(tmp_w);
dest.destructive_append(tmp_x);
dest.destructive_append(tmp_y);
dest.destructive_append(tmp_z);
}
void arrayst::add_array_constraints_if(
const index_sett &index_set,
const if_exprt &expr)
{
// we got x=(c?a:b)
literalt cond_lit=convert(expr.cond());
// get other array index applications
// and add c => x[i]=a[i]
// !c => x[i]=b[i]
// first do true case
for(index_sett::const_iterator
it=index_set.begin();
it!=index_set.end();
it++)
{
index_exprt index_expr1;
index_expr1.type()=ns.follow(expr.type()).subtype();
index_expr1.array()=expr;
index_expr1.index()=*it;
index_exprt index_expr2;
index_expr2.type()=ns.follow(expr.type()).subtype();
index_expr2.array()=expr.true_case();
index_expr2.index()=*it;
assert(index_expr1.type()==index_expr2.type());
// add implication
bvt bv;
bv.push_back(prop.lnot(cond_lit));
bv.push_back(convert(equality_exprt(index_expr1, index_expr2)));
prop.lcnf(bv);
}
// now the false case
for(index_sett::const_iterator
it=index_set.begin();
it!=index_set.end();
it++)
{
index_exprt index_expr1;
index_expr1.type()=ns.follow(expr.type()).subtype();
index_expr1.array()=expr;
index_expr1.index()=*it;
index_exprt index_expr2;
index_expr2.type()=ns.follow(expr.type()).subtype();
index_expr2.array()=expr.false_case();
index_expr2.index()=*it;
assert(index_expr1.type()==index_expr2.type());
// add implication
bvt bv;
bv.push_back(cond_lit);
bv.push_back(convert(equality_exprt(index_expr1, index_expr2)));
prop.lcnf(bv);
}
}
