private void Inst_Addi(MipsInstruction inst)
{
if (!MipsState.Operating64BitMode)
{
try
{
MipsState.WriteGPR32Signed(inst.Rt, MipsState.ReadGPR32Signed(inst.Rs) + (Int32)(Int16)inst.Immediate);
}
catch (OverflowException)
{
CauseException = ExceptionCode.OverFlow;
}
}
else
{
try
{
MipsState.WriteGPRSigned(inst.Rt, MipsState.ReadGPRSigned(inst.Rs) + (Int64)(Int16)inst.Immediate);
}
catch (OverflowException)
{
CauseException = ExceptionCode.OverFlow;
}
}
}
private void Inst_Add(MipsInstruction inst)
{
if (!MipsState.Operating64BitMode)
{
try
{
MipsState.WriteGPR32Signed(inst.Rd, MipsState.ReadGPR32Signed(inst.Rs) + MipsState.ReadGPR32Signed(inst.Rt));
}
catch (OverflowException)
{
CauseException = ExceptionCode.OverFlow;
}
}
else
{
if (MipsState.ReadGPRUnsigned(inst.Rs).IsSigned32() && MipsState.ReadGPRUnsigned(inst.Rt).IsSigned32())
{
try
{
MipsState.WriteGPRSigned(inst.Rd, MipsState.ReadGPRSigned(inst.Rs) + MipsState.ReadGPRSigned(inst.Rt));
}
catch (OverflowException)
{
CauseException = ExceptionCode.OverFlow;
}
}
}
}
private void Inst_Slt(MipsInstruction inst)
{
if (!MipsState.Operating64BitMode)
{
if (MipsState.ReadGPR32Signed(inst.Rs) < MipsState.ReadGPR32Signed(inst.Rt))
{
MipsState.GPRRegs[inst.Rd] = 1;
}
else
{
MipsState.GPRRegs[inst.Rd] = 0;
}
}
else
{
if (MipsState.ReadGPRSigned(inst.Rs) < MipsState.ReadGPRSigned(inst.Rt))
{
MipsState.GPRRegs[inst.Rd] = 1;
}
else
{
MipsState.GPRRegs[inst.Rd] = 0;
}
}
}
private void Inst_Xori(MipsInstruction inst)
{
if (!MipsState.Operating64BitMode)
{
MipsState.WriteGPR32Signed(inst.Rt, MipsState.ReadGPR32Signed(inst.Rs) ^ (Int32)(Int16)inst.Immediate);
}
else
{
MipsState.WriteGPRSigned(inst.Rt, MipsState.ReadGPRSigned(inst.Rs) ^ (Int64)(Int16)inst.Immediate);
}
}
private void Inst_Bgez(MipsInstruction inst)
{
if (!MipsState.Operating64BitMode)
{
DoBranch(MipsState.ReadGPR32Signed(inst.Rs) >= 0, inst);
}
else
{
DoBranch(MipsState.ReadGPRSigned(inst.Rs) >= 0, inst);
}
}
private void Inst_Bltzl(MipsInstruction inst)
{
if (!MipsState.Operating64BitMode)
{
DoBranchLikely(MipsState.ReadGPR32Signed(inst.Rs) < 0, inst);
}
else
{
DoBranchLikely(MipsState.ReadGPRSigned(inst.Rs) < 0, inst);
}
}
private void Inst_Sub(MipsInstruction inst)
{
try
{
MipsState.WriteGPR32Signed(inst.Rd, MipsState.ReadGPR32Signed(inst.Rs) - MipsState.ReadGPR32Signed(inst.Rt));
}
catch (OverflowException)
{
CauseException = ExceptionCode.OverFlow;
}
}
private void Inst_Srvl(MipsInstruction inst)
{
UInt32 result = MipsState.ReadGPR32Unsigned(inst.Rt) >> MipsState.ReadGPR32Signed(inst.Rs) & 0x1F;
if (!MipsState.Operating64BitMode)
{
MipsState.WriteGPR32Unsigned(inst.Rd, result);
}
else
{
MipsState.WriteGPRUnsigned(inst.Rd, (UInt32)(Int32)result);
}
}
private void Inst_Srav(MipsInstruction inst)
{
Int32 result = MipsState.ReadGPR32Signed(inst.Rt) >> (MipsState.ReadGPR32Signed(inst.Rs) & 0x1F);
if (!MipsState.Operating64BitMode)
{
MipsState.WriteGPR32Signed(inst.Rd, result);
}
else
{
MipsState.WriteGPRSigned(inst.Rd, result);
}
}
private void Inst_Sra(MipsInstruction inst)
{
Int32 result = MipsState.ReadGPR32Signed(inst.Rt) >> inst.ShiftAmount;
if (!MipsState.Operating64BitMode)
{
MipsState.WriteGPR32Signed(inst.Rd, result);
}
else
{
MipsState.WriteGPRSigned(inst.Rd, result);
}
}
private void Inst_Slti(MipsInstruction inst)
{
if (!MipsState.Operating64BitMode)
{
Boolean condition = MipsState.ReadGPR32Signed(inst.Rs) < ((Int32)(Int16)inst.Immediate);
MipsState.WriteGPR32Unsigned(inst.Rt, condition ? 1U : 0U);
}
else
{
Boolean condition = MipsState.ReadGPRSigned(inst.Rs) < ((Int64)(Int16)inst.Immediate);
MipsState.WriteGPRUnsigned(inst.Rt, condition ? 1UL : 0UL);
}
}
private void Inst_Mult(MipsInstruction inst)
{
if (!MipsState.Operating64BitMode)
{
Int64 product = MipsState.ReadGPR32Signed(inst.Rs) * MipsState.ReadGPR32Signed(inst.Rt);
MipsState.Hi = (UInt64)(product >> 32);
MipsState.Lo = (UInt64)(product & 0xFFFF);
}
else
{
Int64 product = (Int64)MipsState.ReadGPR32Signed(inst.Rs) * (Int64)MipsState.ReadGPR32Signed(inst.Rt);
MipsState.Hi = (UInt64)(product >> 32);
MipsState.Lo = (UInt64)(product & 0xFFFF);
}
}
private void Inst_Tlt(MipsInstruction inst)
{
Boolean condition;
if (!MipsState.Operating64BitMode)
{
condition = MipsState.ReadGPR32Signed(inst.Rs) < MipsState.ReadGPR32Signed(inst.Rt);
}
else
{
condition = MipsState.ReadGPRSigned(inst.Rs) < MipsState.ReadGPRSigned(inst.Rt);
}
if (condition)
{
CauseException = ExceptionCode.Trap;
}
}
private void Inst_Teqi(MipsInstruction inst)
{
Boolean condition;
if (!MipsState.Operating64BitMode)
{
condition = MipsState.ReadGPR32Signed(inst.Rs) == (Int32)(Int16)inst.Immediate;
}
else
{
condition = MipsState.ReadGPRSigned(inst.Rs) == (Int64)(Int16)inst.Immediate;
}
if (condition)
{
CauseException = ExceptionCode.Trap;
}
}
private void Inst_Div(MipsInstruction inst)
{
try
{
unchecked
{
if (!MipsState.Addressing64BitMode || (MipsState.ReadGPRUnsigned(inst.Rs).IsSigned32() && MipsState.ReadGPRUnsigned(inst.Rt).IsSigned32()))
{
/* Data input is always the size of a MIPS word */
MipsState.Hi = (UInt64)(MipsState.ReadGPR32Signed(inst.Rs) / MipsState.ReadGPR32Signed(inst.Rt));
MipsState.Lo = (UInt64)(MipsState.ReadGPR32Signed(inst.Rs) % MipsState.ReadGPR32Signed(inst.Rt));
}
}
}
catch (DivideByZeroException)
{
MipsState.Hi = 0;
MipsState.Lo = 0;
return;
}
}
private void Inst_Sllv(MipsInstruction inst)
{
Int32 shiftAmount = MipsState.ReadGPR32Signed(inst.Rs) & 0x1F;
if (!MipsState.Operating64BitMode)
{
MipsState.WriteGPR32Unsigned(inst.Rd, MipsState.ReadGPR32Unsigned(inst.Rt) << shiftAmount);
}
else
{
UInt64 result = MipsState.ReadGPRUnsigned(inst.Rt) << shiftAmount;
/* Truncate */
if (shiftAmount == 0)
{
MipsState.WriteGPRSigned(inst.Rd, (Int32)(UInt32)result);
}
else
{
MipsState.WriteGPRUnsigned(inst.Rd, result);
}
}
}
private void Inst_Dsrav(MipsInstruction inst)
{
if (MipsState.Operating64BitMode)
{
MipsState.WriteGPRSigned(inst.Rd, MipsState.ReadGPRSigned(inst.Rt) >> (MipsState.ReadGPR32Signed(inst.Rs) & 0x3F));
}
else
{
CauseException = ExceptionCode.ReservedInstruction;
}
}
