public List <Instruction> CodeGen()
{
var b = new List <Instruction>();
if (body.Count == 0)
{
// Empty loop, just wait on self until fails...
b.AddRange(branch.CodeGen(0, 1));
}
else
{
FieldSRef.ResetScratchInts();
b.AddRange(RegVRef.rScratchInts.PutFromReg(RegVRef.rNull));
var flatbody = body.CodeGen();
b.AddRange(branch.CodeGen(1, flatbody.Count + 2));
b.AddRange(flatbody);
b.Add(new Jump {
target = new IntSExpr(-b.Count), relative = true
});
b.AddRange(RegVRef.rScratchInts.PutFromReg(RegVRef.rNull));
FieldSRef.ResetScratchInts();
}
return(b);
}
public List <Instruction> FetchToReg(RegVRef dest)
{
var code = new List <Instruction>();
var cmd = Command.AsReg();
if (cmd == null)
{
cmd = RegVRef.rScratchTab;
code.AddRange(Command.FetchToReg(cmd));
}
var data = Data.AsReg();
if (data == null)
{
data = cmd == RegVRef.rScratchTab ? RegVRef.rScratchInts : RegVRef.rScratchTab;
if (data == RegVRef.rScratchInts)
{
FieldSRef.ResetScratchInts();
}
code.AddRange(Data.FetchToReg(data));
}
code.Add(new Instruction
{
opcode = Opcode.ConMan,
op1 = cmd,
op2 = data,
dest = dest,
});
if (data == RegVRef.rScratchInts)
{
code.AddRange(data.PutFromReg(RegVRef.rNull));
}
return(code);
}
public List <Instruction> BuildFunction()
{
var b = new List <Instruction>();
// save call site (in r8.signal-0)
b.Add(new Push(RegVRef.rScratchInts));
if (localints.Count > 0)
{
// save parent localints
b.Add(new Push(RegVRef.rLocalInts("parent")));
}
// push regs as needed
foreach (var sym in locals.Where(s => s.type == SymbolType.Register))
{
if (sym.fixedAddr.HasValue)
{
b.Add(new Push(new RegVRef(sym.fixedAddr.Value)));
}
}
// wind stack down for locals if needed
if (framesize > 0)
{
b.Add(new Instruction
{
opcode = Opcode.Add,
op1 = FieldSRef.Imm1(),
imm1 = new IntSExpr(-framesize),
acc = true,
dest = FieldSRef.Pointer(PointerIndex.CallStack)
});
}
// copy params if named
//int args or null in r8
var intparas = locals.Where(sym => sym.type == SymbolType.Parameter && sym.datatype == "int").ToList();
if (intparas.Count() > 0)
{
for (int i = 0; i < intparas.Count(); i++)
{
b.Add(new Instruction
{
opcode = Opcode.Add,
op1 = FieldSRef.IntArg(name, intparas[i].name),
dest = FieldSRef.LocalInt(name, intparas[i].name),
acc = i != 0,
});
}
}
FieldSRef.ResetScratchInts();
b.AddRange(RegVRef.rScratchInts.PutFromReg(RegVRef.rNull));
// body
b.AddRange(body.CodeGen());
// convert rjmp __return => rjmp <integer> to here.
for (int i = 0; i < b.Count; i++)
{
var inst = b[i];
if ((inst.imm1 as AddrSExpr)?.symbol == "__return")
{
inst.imm1 = new IntSExpr(b.Count - i);
}
if ((inst.imm2 as AddrSExpr)?.symbol == "__return")
{
inst.imm2 = new IntSExpr(b.Count - i);
}
b[i] = inst;
}
// wind stack back up for locals if needed
if (framesize > 0)
{
b.Add(new Instruction
{
opcode = Opcode.Add,
op1 = FieldSRef.Imm1(),
imm1 = new IntSExpr(framesize),
acc = true,
dest = FieldSRef.Pointer(PointerIndex.CallStack)
});
}
// restore registers
foreach (var sym in locals.Where(s => s.type == SymbolType.Register).Reverse())
{
if (sym.fixedAddr.HasValue)
{
b.Add(new Pop(new RegVRef(sym.fixedAddr.Value)));
}
}
if (localints.Count > 0)
{
// restore parent localints
b.Add(new Pop(RegVRef.rLocalInts("parent")));
}
// get return site
b.Add(new Exchange(RegVRef.rScratchTab));
b.Add(new Instruction
{
opcode = Opcode.Sub,
op1 = FieldSRef.VarField(RegVRef.rScratchTab, "signal-0"),
op2 = FieldSRef.CallSite,
dest = FieldSRef.CallSite,
acc = true
});
b.Add(new Pop(RegVRef.rScratchTab));
// jump to return site
b.Add(new Jump {
target = FieldSRef.CallSite
});
return(b);
}