Tr_exp Tr_whileExp(Tr_exp cond, Tr_exp body){
debug("Tr_whileExp");
T_stm st;
struct Cx cx_cond = unCx(cond);
Temp_label t = Temp_newlabel();
Temp_label f = LL_peek();//Get done label from the list, which should have been prepared before this function is called.
Temp_label start = Temp_newlabel();
doPatch(cx_cond.trues, t);
doPatch(cx_cond.falses, f);
/*
T_Label start
cx_cond.stm (true->t, false->f)
T_Label(t)
body
T_Jump start
T_Label(f)
*/
st = T_Seq(T_Label(start),
T_Seq(cx_cond.stm,
T_Seq(T_Label(t),
T_Seq(unNx(body),
T_Seq(
T_Jump(
T_Name(start),
Temp_LabelList(start, NULL)
),
T_Label(f)
)
)
)
)
);
//Pop the label as it's no longer used
LL_pop();
return Tr_Nx(st);
}
Tr_exp Tr_ifExp(Tr_exp cond, Tr_exp thenb, Tr_exp elseb){
T_exp ex;
T_stm st;
Tr_exp ret;
struct Cx cx_cond = unCx(cond);
Temp_label t = Temp_newlabel();
Temp_label f = Temp_newlabel();
Temp_label join = Temp_newlabel();
doPatch(cx_cond.trues, t);
doPatch(cx_cond.falses, f);
if(elseb==NULL){
//case 1: if-then
debug("Tr_ifExp: if-then");
st = T_Seq(cx_cond.stm,
T_Seq(T_Label(t),
T_Seq(unNx(thenb),
T_Label(f)
)
)
);
ret = Tr_Nx(st);
} else {
//case 2: if-then-else
if(thenb->kind==Tr_nx && elseb->kind==Tr_nx){
debug("Tr_ifExp: if-then-else (2 nx)");
//special case: two statements
st = T_Seq(cx_cond.stm,
T_Seq(T_Label(t),
T_Seq(unNx(thenb),
T_Seq(
T_Jump(
T_Name(join),
Temp_LabelList(join, NULL)
),
T_Seq(T_Label(f),
T_Seq(unNx(elseb),
T_Label(join)
)
)
)
)
)
);
ret = Tr_Nx(st);
//TODO: special case - two cx.
} else {
debug("Tr_ifExp: if-then-else");
Temp_temp r = Temp_newtemp();
ex = T_Eseq(cx_cond.stm,
T_Eseq(T_Label(t),
T_Eseq(T_Move(T_Temp(r), unEx(thenb)),
T_Eseq(
T_Jump(
T_Name(join),
Temp_LabelList(join, NULL)
),
T_Eseq(T_Label(f),
T_Eseq(T_Move(T_Temp(r), unEx(elseb)),
T_Eseq(T_Label(join),
T_Temp(r)
)
)
)
)
)
)
);
ret = Tr_Ex(ex);
}
}
return ret;
}
//@@@ print Tr_exp
void print(Tr_exp et, FILE * out) {
if (et->kind == Tr_ex) printExp(unEx(et), out);
if (et->kind == Tr_nx) printStm(unNx(et), out);
if (et->kind == Tr_cx) printStm(unCx(et).stm, out);
}
Cx::unEx()
{
Temp *tmp = gcnew(Temp, ());
tree::TEMP *r = _TEMP(tmp);
tree::CONST *const_1 = _CONST(1);
tree::CONST *const_0 = _CONST(0);
tree::MOVE *r_1 = _MOVE(r, const_1);
tree::MOVE *r_0 = _MOVE(r, const_0);
Label *t = gcnew(Label, ());
Label *f = gcnew(Label, ());
tree::LABEL *l_T = _LABEL(t);
tree::LABEL *l_F = _LABEL(f);
tree::Stm *cmp = unCx(t, f);
tree::SEQMaker sm;
sm.add(r_1);
sm.add(cmp);
sm.add(l_F);
sm.add(r_0);
sm.add(l_T);
tree::SEQ *seq = sm.make();//tree::makeSEQ(r_1, cmp, l_F, r_0, l_T);
tree::ESEQ *eseq = _ESEQ(seq, r);
return eseq;
}
tree::Stm *
Cx::unNx()
{
