public void InitRegisters()
{
availableRegisters = new List <MIPSRegister>();
for (int i = 0; i < gpRegisters.Length; i++)
{
availableRegisters[i] = new MIPSRegister(gpRegisters[i]);
}
}
public MIPSRegister GetRegister()
{
if (availableRegisters.Count == 0)
{
throw new Exception("No more registers!");
}
MIPSRegister reg = availableRegisters[0];
availableRegisters.RemoveAt(0);
return(reg);
}
public void EmitMalloc(MIPSRegister reg, short numbytes)
{
// put v0 + a0 on the stack
EmitLoadStore("sw", "$v0", -4, "$sp");
EmitLoadStore("sw", "$a0", -8, "$sp");
// set v0 to 9 - sbrk
EmitImmediate("addi", "$v0", "$zero", 9);
// set a0 to num bytes
EmitImmediate("addi", "$a0", "$zero", numbytes);
// call syscall
Emit("syscall");
// put the returned address in v0 to reg
Emit("add", reg, "$zero", "$v0");
// restore v0 and a0
EmitLoadStore("lw", "$v0", -4, "$sp");
EmitLoadStore("lw", "$a0", -8, "$sp");
}
public void ReleaseRegister(MIPSRegister reg)
{
availableRegisters.Insert(0, reg);
}
public void EmitLabelJump(string mnemonic, MIPSRegister s, MIPSRegister t, string label)
{
EmitLabelJump(mnemonic, s.Name, t.Name, label);
}
public void EmitImmediate(string mnemonic, MIPSRegister t, MIPSRegister s, short C)
{
EmitImmediate(t.Name, s.Name, C);
}
public void Emit(string mnemonic, MIPSRegister s, MIPSRegister t)
{
Emit(mnemonic, s.Name, t.Name);
}
public void Emit(string mnemonic, MIPSRegister d, MIPSRegister s, string t)
{
Emit(mnemonic, d.Name, s.Name, t);
}
public void Emit(string mnemonic, MIPSRegister d, string s, MIPSRegister t)
{
Emit(mnemonic, d.Name, s, t.Name);
}
public void Emit(string mnemonic, MIPSRegister d, int C)
{
Emit(string.Format("{0} {1},{2}", mnemonic, d.Name, C));
}
public void EmitLoadStore(string mnemonic, MIPSRegister t, short C, MIPSRegister s)
{
EmitLoadStore(mnemonic, t.Name, C, s.Name);
}
