public static void EmitDynamicTableCall(ArmEmitterContext context, Operand tableAddress, Operand address, bool isJump)
{
// Loop over elements of the dynamic table. Unrolled loop.
Operand endLabel = Label();
Operand fallbackLabel = Label();
void EmitTableEntry(Operand entrySkipLabel)
{
// Try to take this entry in the table if its guest address equals 0.
Operand gotResult = context.CompareAndSwap(tableAddress, Const(0L), address);
// Is the address ours? (either taken via CompareAndSwap (0), or what was already here)
context.BranchIfFalse(entrySkipLabel,
context.BitwiseOr(
context.ICompareEqual(gotResult, address),
context.ICompareEqual(gotResult, Const(0L)))
);
// It's ours, so what function is it pointing to?
Operand targetFunctionPtr = context.Add(tableAddress, Const(8L));
Operand targetFunction = context.Load(OperandType.I64, targetFunctionPtr);
// Call the function.
// We pass in the entry address as the guest address, as the entry may need to be updated by the
// indirect call stub.
EmitNativeCallWithGuestAddress(context, targetFunction, tableAddress, isJump);
context.Branch(endLabel);
}
// Currently this uses a size of 1, as higher values inflate code size for no real benefit.
for (int i = 0; i < JumpTable.DynamicTableElems; i++)
{
if (i == JumpTable.DynamicTableElems - 1)
{
// If this is the last entry, avoid emitting the additional label and add.
EmitTableEntry(fallbackLabel);
}
else
{
Operand nextLabel = Label();
EmitTableEntry(nextLabel);
context.MarkLabel(nextLabel);
// Move to the next table entry.
tableAddress = context.Add(tableAddress, Const((long)JumpTable.JumpTableStride));
}
}
context.MarkLabel(fallbackLabel);
EmitBranchFallback(context, address, isJump);
context.MarkLabel(endLabel);
}
private static void EmitDiv(ArmEmitterContext context, bool unsigned)
{
OpCodeAluBinary op = (OpCodeAluBinary)context.CurrOp;
// If Rm == 0, Rd = 0 (division by zero).
Operand n = GetIntOrZR(context, op.Rn);
Operand m = GetIntOrZR(context, op.Rm);
Operand divisorIsZero = context.ICompareEqual(m, Const(m.Type, 0));
Operand lblBadDiv = Label();
Operand lblEnd = Label();
context.BranchIfTrue(lblBadDiv, divisorIsZero);
if (!unsigned)
{
// If Rn == INT_MIN && Rm == -1, Rd = INT_MIN (overflow).
bool is32Bits = op.RegisterSize == RegisterSize.Int32;
Operand intMin = is32Bits ? Const(int.MinValue) : Const(long.MinValue);
Operand minus1 = is32Bits ? Const(-1) : Const(-1L);
Operand nIsIntMin = context.ICompareEqual(n, intMin);
Operand mIsMinus1 = context.ICompareEqual(m, minus1);
Operand lblGoodDiv = Label();
context.BranchIfFalse(lblGoodDiv, context.BitwiseAnd(nIsIntMin, mIsMinus1));
SetAluDOrZR(context, intMin);
context.Branch(lblEnd);
context.MarkLabel(lblGoodDiv);
}
Operand d = unsigned
? context.DivideUI(n, m)
: context.Divide(n, m);
SetAluDOrZR(context, d);
context.Branch(lblEnd);
context.MarkLabel(lblBadDiv);
SetAluDOrZR(context, Const(op.GetOperandType(), 0));
context.MarkLabel(lblEnd);
}
public static void EmitDiv(ArmEmitterContext context, bool unsigned)
{
Operand n = GetAluN(context);
Operand m = GetAluM(context);
Operand zero = Const(m.Type, 0);
Operand divisorIsZero = context.ICompareEqual(m, zero);
Operand lblBadDiv = Label();
Operand lblEnd = Label();
context.BranchIfTrue(lblBadDiv, divisorIsZero);
if (!unsigned)
{
// ARM64 behaviour: If Rn == INT_MIN && Rm == -1, Rd = INT_MIN (overflow).
// TODO: tests to ensure A32 works the same
Operand intMin = Const(int.MinValue);
Operand minus1 = Const(-1);
Operand nIsIntMin = context.ICompareEqual(n, intMin);
Operand mIsMinus1 = context.ICompareEqual(m, minus1);
Operand lblGoodDiv = Label();
context.BranchIfFalse(lblGoodDiv, context.BitwiseAnd(nIsIntMin, mIsMinus1));
EmitAluStore(context, intMin);
context.Branch(lblEnd);
context.MarkLabel(lblGoodDiv);
}
Operand res = unsigned
? context.DivideUI(n, m)
: context.Divide(n, m);
EmitAluStore(context, res);
context.Branch(lblEnd);
context.MarkLabel(lblBadDiv);
EmitAluStore(context, zero);
context.MarkLabel(lblEnd);
}
public static void Cmeq_V(ArmEmitterContext context)
{
if (Optimizations.UseSse41)
{
OpCodeSimd op = (OpCodeSimd)context.CurrOp;
Operand n = GetVec(op.Rn);
Operand m;
if (op is OpCodeSimdReg binOp)
{
m = GetVec(binOp.Rm);
}
else
{
m = context.VectorZero();
}
Intrinsic cmpInst = X86PcmpeqInstruction[op.Size];
Operand res = context.AddIntrinsic(cmpInst, n, m);
if (op.RegisterSize == RegisterSize.Simd64)
{
res = context.VectorZeroUpper64(res);
}
context.Copy(GetVec(op.Rd), res);
}
else
{
EmitCmpOp(context, (op1, op2) => context.ICompareEqual(op1, op2), scalar: false);
}
}
private static void EmitNativeCall(ArmEmitterContext context, Operand nativeContextPtr, Operand funcAddr, bool isJump = false)
{
context.StoreToContext();
if (isJump)
{
context.Tailcall(funcAddr, nativeContextPtr);
}
else
{
OpCode op = context.CurrOp;
Operand returnAddress = context.Call(funcAddr, OperandType.I64, nativeContextPtr);
context.LoadFromContext();
// Note: The return value of a translated function is always an Int64 with the
// address execution has returned to. We expect this address to be immediately after the
// current instruction, if it isn't we keep returning until we reach the dispatcher.
Operand nextAddr = Const((long)op.Address + op.OpCodeSizeInBytes);
// Try to continue within this block.
// If the return address isn't to our next instruction, we need to return so the JIT can figure out what to do.
Operand lblContinue = context.GetLabel(nextAddr.Value);
// We need to clear out the call flag for the return address before comparing it.
context.BranchIfTrue(lblContinue, context.ICompareEqual(context.BitwiseAnd(returnAddress, Const(~CallFlag)), nextAddr));
context.Return(returnAddress);
}
}
public static void Vtst(ArmEmitterContext context)
{
EmitVectorBinaryOpZx32(context, (op1, op2) =>
{
Operand isZero = context.ICompareEqual(context.BitwiseAnd(op1, op2), Const(0));
return(context.ConditionalSelect(isZero, Const(0), Const(-1)));
});
}
public static void EmitSbcsCCheck(ArmEmitterContext context, Operand n, Operand m)
{
// C = (Rn == Rm && CIn) || Rn > Rm
Operand cIn = GetFlag(PState.CFlag);
Operand cOut = context.BitwiseAnd(context.ICompareEqual(n, m), cIn);
cOut = context.BitwiseOr(cOut, context.ICompareGreaterUI(n, m));
SetFlag(context, PState.CFlag, cOut);
}
public static void EmitAdcsCCheck(ArmEmitterContext context, Operand n, Operand d)
{
// C = (Rd == Rn && CIn) || Rd < Rn
Operand cIn = GetFlag(PState.CFlag);
Operand cOut = context.BitwiseAnd(context.ICompareEqual(d, n), cIn);
cOut = context.BitwiseOr(cOut, context.ICompareLessUI(d, n));
SetFlag(context, PState.CFlag, cOut);
}
private static void EmitContinueOrReturnCheck(ArmEmitterContext context, Operand retVal)
{
// Note: The return value of the called method will be placed
// at the Stack, the return value is always a Int64 with the
// return address of the function. We check if the address is
// correct, if it isn't we keep returning until we reach the dispatcher.
ulong nextAddr = GetNextOpAddress(context.CurrOp);
if (context.CurrBlock.Next != null)
{
Operand lblContinue = Label();
context.BranchIfTrue(lblContinue, context.ICompareEqual(retVal, Const(nextAddr)));
context.Return(Const(nextAddr));
context.MarkLabel(lblContinue);
}
else
{
context.Return(Const(nextAddr));
}
}
public static Operand GetMShiftedByReg(ArmEmitterContext context, IOpCode32AluRsReg op, bool setCarry)
{
Operand m = GetIntA32(context, op.Rm);
Operand s = context.ZeroExtend8(OperandType.I32, GetIntA32(context, op.Rs));
Operand shiftIsZero = context.ICompareEqual(s, Const(0));
Operand zeroResult = m;
Operand shiftResult = m;
setCarry &= ShouldSetFlags(context);
switch (op.ShiftType)
{
case ShiftType.Lsl: shiftResult = EmitLslC(context, m, setCarry, s, shiftIsZero); break;
case ShiftType.Lsr: shiftResult = EmitLsrC(context, m, setCarry, s, shiftIsZero); break;
case ShiftType.Asr: shiftResult = EmitAsrC(context, m, setCarry, s, shiftIsZero); break;
case ShiftType.Ror: shiftResult = EmitRorC(context, m, setCarry, s, shiftIsZero); break;
}
return(context.ConditionalSelect(shiftIsZero, zeroResult, shiftResult));
}
private static void EmitContinueOrReturnCheck(ArmEmitterContext context, Operand returnAddress)
{
// Note: The return value of a translated function is always an Int64 with the
// address execution has returned to. We expect this address to be immediately after the
// current instruction, if it isn't we keep returning until we reach the dispatcher.
Operand nextAddr = Const(GetNextOpAddress(context.CurrOp));
// Try to continue within this block.
// If the return address isn't to our next instruction, we need to return so the JIT can figure out what to do.
Operand lblContinue = Label();
// We need to clear out the call flag for the return address before comparing it.
context.BranchIfTrue(lblContinue, context.ICompareEqual(context.BitwiseAnd(returnAddress, Const(~CallFlag)), nextAddr));
context.Return(returnAddress);
context.MarkLabel(lblContinue);
if (context.CurrBlock.Next == null)
{
// No code following this instruction, try and find the next block and jump to it.
EmitTailContinue(context, nextAddr);
}
}
public static Operand GetCondTrue(ArmEmitterContext context, Condition condition)
{
Operand cmpResult = context.TryGetComparisonResult(condition);
if (cmpResult != null)
{
return(cmpResult);
}
Operand value = Const(1);
Operand Inverse(Operand val)
{
return(context.BitwiseExclusiveOr(val, Const(1)));
}
switch (condition)
{
case Condition.Eq:
value = GetFlag(PState.ZFlag);
break;
case Condition.Ne:
value = Inverse(GetFlag(PState.ZFlag));
break;
case Condition.GeUn:
value = GetFlag(PState.CFlag);
break;
case Condition.LtUn:
value = Inverse(GetFlag(PState.CFlag));
break;
case Condition.Mi:
value = GetFlag(PState.NFlag);
break;
case Condition.Pl:
value = Inverse(GetFlag(PState.NFlag));
break;
case Condition.Vs:
value = GetFlag(PState.VFlag);
break;
case Condition.Vc:
value = Inverse(GetFlag(PState.VFlag));
break;
case Condition.GtUn:
{
Operand c = GetFlag(PState.CFlag);
Operand z = GetFlag(PState.ZFlag);
value = context.BitwiseAnd(c, Inverse(z));
break;
}
case Condition.LeUn:
{
Operand c = GetFlag(PState.CFlag);
Operand z = GetFlag(PState.ZFlag);
value = context.BitwiseOr(Inverse(c), z);
break;
}
case Condition.Ge:
{
Operand n = GetFlag(PState.NFlag);
Operand v = GetFlag(PState.VFlag);
value = context.ICompareEqual(n, v);
break;
}
case Condition.Lt:
{
Operand n = GetFlag(PState.NFlag);
Operand v = GetFlag(PState.VFlag);
value = context.ICompareNotEqual(n, v);
break;
}
case Condition.Gt:
{
Operand n = GetFlag(PState.NFlag);
Operand z = GetFlag(PState.ZFlag);
Operand v = GetFlag(PState.VFlag);
value = context.BitwiseAnd(Inverse(z), context.ICompareEqual(n, v));
break;
}
case Condition.Le:
{
Operand n = GetFlag(PState.NFlag);
Operand z = GetFlag(PState.ZFlag);
Operand v = GetFlag(PState.VFlag);
value = context.BitwiseOr(z, context.ICompareNotEqual(n, v));
break;
}
}
return(value);
}
public static void EmitNZFlagsCheck(ArmEmitterContext context, Operand d)
{
SetFlag(context, PState.NFlag, context.ICompareLess(d, Const(d.Type, 0)));
SetFlag(context, PState.ZFlag, context.ICompareEqual(d, Const(d.Type, 0)));
}
public static void Cmeq_S(ArmEmitterContext context)
{
EmitCmpOp(context, (op1, op2) => context.ICompareEqual(op1, op2), scalar: true);
}