/// <summary>
/// Emits a conditional jump instruction to the specified position.
/// </summary>
/// <param name="condition">The condition code where the jump is executed.</param>
/// <param name="blockIndex">The destination basic block index, used for disassembly.</param>
/// <param name="target">The jump target position. For blocks, this is received from <see cref="StartBlock"/>.</param>
public void EmitJcc(X64Condition condition, int blockIndex, int target)
{
_disassemblyWriter?.WriteLine($"{Indent}j{GetConditionName(condition)} LB_{blockIndex}");
_outputStream.WriteByte(0x0F);
_outputStream.WriteByte((byte)(0x80 | (byte)condition));
Emit4ByteImmediate((uint)(target - _outputStream.Position - 4));
}
private void EmitConditionalJump(X64Condition condition, int targetBlock, int currentBlock)
{
var emitter = _peWriter.Emitter;
if (targetBlock <= currentBlock)
{
emitter.EmitJcc(condition, targetBlock, _blockPositions[targetBlock]);
}
else
{
emitter.EmitJccWithFixup(condition, targetBlock, out var fixup);
_fixupsForMethod.Add(fixup);
}
}
/// <summary>
/// Emits a set byte instruction with the specified condition code.
/// </summary>
public void EmitSetcc(X64Condition condition, StorageLocation <X64Register> dest)
{
if (!dest.IsRegister)
{
throw new NotImplementedException("Setcc on stack");
}
if (dest.Register >= X64Register.Xmm0)
{
throw new InvalidOperationException("Setcc on XMM register");
}
_disassemblyWriter?.WriteLine($"{Indent}set{GetConditionName(condition)} {GetRegisterName(dest.Register, 1)}");
var(encodedReg, needB) = GetRegisterEncoding(dest.Register);
EmitRexPrefixIfNeeded(false, false, false, needB);
_outputStream.WriteByte(0x0F);
_outputStream.WriteByte((byte)(0x90 | (byte)condition));
EmitModRmForSingleRegister(encodedReg);
}
/// <summary>
/// Emits a conditional jump instruction to an undetermined position and returns a <see cref="Fixup"/>
/// value that can be used to fix the target position once it is known.
/// </summary>
/// <param name="condition">The condition code where the jump is executed.</param>
/// <param name="blockIndex">
/// The destination basic block index.
/// This will be used as a tag on the <see cref="Fixup"/>.
/// </param>
/// <param name="fixup">Information required for fixing the target later.</param>
public void EmitJccWithFixup(X64Condition condition, int blockIndex, out Fixup fixup)
{
// The position points to the displacement, which is 2 bytes past the start of the instruction
fixup = new Fixup(FixupType.RelativeJump, blockIndex, (int)_outputStream.Position + 2);
EmitJcc(condition, blockIndex, 0);
}
private void EmitConditionalSet(X64Condition condition, in StorageLocation <X64Register> destLocation)
