/// <summary>
/// Given an image reader positioned at a Keil sparse switch table, generates
/// an <see cref="RtlInstructionCluster" /> that implements the table as a
/// sequence of RTL if-instructions.
/// </summary>
private RtlInstructionCluster MakeCluster(Address addrPatch, ImageReader rdr)
{
var binder = new StorageBinder();
var areg = binder.EnsureRegister(Registers.A);
var m = new RtlEmitter(new List <RtlInstruction>());
while (rdr.TryReadBeUInt16(out ushort uAddrDst))
{
if (uAddrDst == 0)
{
if (!rdr.TryReadBeUInt16(out uAddrDst))
{
break;
}
m.Goto(Address.Ptr16(uAddrDst));
break;
}
if (!rdr.TryReadByte(out byte bValue))
{
break;
}
var addrDst = Address.Ptr16(uAddrDst);
m.BranchInMiddleOfInstruction(m.Eq(areg, bValue), addrDst, InstrClass.ConditionalTransfer);
}
int length = (int)(rdr.Address - addrPatch);
var cluster = m.MakeCluster(addrPatch, length, InstrClass.Transfer);
return(cluster);
}
private Identifier Reg(string name)
{
var reg = arch.GetRegister(name);
return(binder.EnsureRegister(reg));
}
private Identifier Reg(int rn)
{
var reg = arch.GetRegister(rn);
return(binder.EnsureRegister(reg));
}
