string CBackendx86::Operand(const CTac *op)
{
string operand;
// TODO
// return a string representing op
// hint: take special care of references (op of type CTacReference)
std::stringstream buffer ;
buffer << op ;
CScope *cs = GetScope();
CSymtab *st = cs->GetSymbolTable();
vector<CSymbol*> slist = st->GetSymbols();
vector< CSymbol * > symbols = st->GetSymbols() ;
//CTacName
if (st->FindSymbol(buffer.str()) != NULL){
operand = buffer.str() ;
}
//CTacConstant
else if (buffer.str()[0] > 47 && buffer.str()[0] < 58){
operand = Imm(atoi(buffer.str().c_str())) ;
}
//CTacReference
else {
}
return operand ;
}
void CBackendx86::EmitLocalData(CScope *scope) // initializes array's meta-data
{
assert(scope != NULL);
CSymtab* symtab = scope->GetSymbolTable();
vector<CSymbol*> slist = symtab->GetSymbols();
vector<CSymbol*>::iterator it;
for(it = slist.begin(); it != slist.end(); it++) {
const CArrayType* typ = dynamic_cast<const CArrayType*>((*it)->GetDataType());
if(typ != NULL && (*it)->GetSymbolType() == stLocal && (dynamic_cast<CSymParam*>(*it) == NULL)) {
// just initialize the arrays that are local and are not param
int offset = (*it)->GetOffset();
string base = (*it)->GetBaseRegister();
int dim = typ->GetNDim();
stringstream ss, ss2;
ss << "$" << dim << "," << offset << "(" << base << ")";
ss2 << "local array '" << (*it)->GetName() << "': " << dim << " dimensions";
EmitInstruction("movl", ss.str(), ss2.str()); // store the dimension meta-data
int dimcount = 1;
while(typ != NULL) {
stringstream ss, ss2;
offset += 4;
int n = typ->GetNElem();
ss << "$" << n << "," << offset << "(" << base << ")";
ss2 << " dimension " << dimcount << ": " << n << " elements";
EmitInstruction("movl", ss.str(), ss2.str()); // store the meta-data of length of each dimension
typ = dynamic_cast<const CArrayType*>(typ->GetInnerType());
dim++;
dimcount++;
}
}
}
}
void CBackendx86::EmitGlobalData(CScope *scope)
{
assert(scope != NULL);
// emit the globals for the current scope
CSymtab *st = scope->GetSymbolTable();
assert(st != NULL);
bool header = false;
vector<CSymbol*> slist = st->GetSymbols();
_out << dec;
size_t size = 0;
for (size_t i=0; i<slist.size(); i++) {
CSymbol *s = slist[i];
const CType *t = s->GetDataType();
if (s->GetSymbolType() == stGlobal) {
if (!header) {
_out << _ind << "# scope: " << scope->GetName() << endl;
header = true;
}
// insert alignment only when necessary
if ((t->GetAlign() > 1) && (size % t->GetAlign() != 0)) {
size += t->GetAlign() - size % t->GetAlign();
_out << setw(4) << " " << ".align "
<< right << setw(3) << t->GetAlign() << endl;
}
_out << left << setw(36) << s->GetName() + ":" << "# " << t << endl;
if (t->IsArray()) {
const CArrayType *a = dynamic_cast<const CArrayType*>(t);
assert(a != NULL);
int dim = a->GetNDim();
_out << setw(4) << " "
<< ".long " << right << setw(4) << dim << endl;
for (int d=0; d<dim; d++) {
assert(a != NULL);
_out << setw(4) << " "
<< ".long " << right << setw(4) << a->GetNElem() << endl;
a = dynamic_cast<const CArrayType*>(a->GetInnerType());
}
}
const CDataInitializer *di = s->GetData();
if (di != NULL) {
const CDataInitString *sdi = dynamic_cast<const CDataInitString*>(di);
assert(sdi != NULL); // only support string data initializers for now
_out << left << setw(4) << " "
<< ".asciz " << '"' << sdi->GetData() << '"' << endl;
} else {
_out << left << setw(4) << " "
<< ".skip " << dec << right << setw(4) << t->GetDataSize()
<< endl;
}
size += t->GetSize();
}
}
_out << endl;
// emit globals in subscopes (necessary if we support static local variables)
vector<CScope*>::const_iterator sit = scope->GetSubscopes().begin();
while (sit != scope->GetSubscopes().end()) EmitGlobalData(*sit++);
}
