/// <summary>
/// Visitation function for <see cref="IX86Visitor.Call"/> instructions.
/// </summary>
/// <param name="context">The context.</param>
void IX86Visitor.Call(Context context)
{
if (context.Operand1 == null)
return;
if (!context.Operand1.IsCPURegister)
return;
var before = context.Previous;
if (!before.Result.IsCPURegister)
return;
if (context.Operand1.Register != before.Result.Register)
return;
before.SetInstruction(X86.Call, null, before.Operand1);
context.Delete(false);
}
/// <summary>
/// Visitation function for <see cref="IX86Visitor.Nop"/> instructions.
/// </summary>
/// <param name="context">The context.</param>
void IX86Visitor.Nop(Context context)
{
context.Delete(false);
}
/// <summary>
/// Visitation function for <see cref="IX86Visitor.Call"/> instructions.
/// </summary>
/// <param name="context">The context.</param>
void IX86Visitor.Call(Context context)
{
if (context.Operand1 == null)
return;
if (!context.Operand1.IsCPURegister)
return;
var before = context.Previous;
while (before.IsEmpty && !before.IsBlockStartInstruction)
{
before = before.Previous;
}
if (before == null || before.IsBlockStartInstruction)
return;
if (!before.Result.IsCPURegister)
return;
if (context.Operand1.Register != before.Result.Register)
return;
before.SetInstruction(X86.Call, null, before.Operand1);
context.Delete(false);
}
/// <summary>
/// Visitation function for <see cref="IX86Visitor.Mov"/> instructions.
/// </summary>
/// <param name="context">The context.</param>
void IX86Visitor.Mov(Context context)
{
if (context.Result.IsCPURegister && context.Operand1.IsCPURegister && context.Result.Register == context.Operand1.Register)
{
context.Delete(false);
return;
}
// Mov can not use ESI or EDI registers with 8 or 16 bit memory or register
if (context.Operand1.IsCPURegister && (context.Result.IsMemoryAddress || context.Result.IsCPURegister)
&& (context.Result.IsByte || context.Result.IsShort || context.Result.IsChar || context.Result.IsBoolean)
&& (context.Operand1.Register == GeneralPurposeRegister.ESI || context.Operand1.Register == GeneralPurposeRegister.EDI))
{
Operand source = context.Operand1;
Operand dest = context.Result;
Operand EAX = Operand.CreateCPURegister(TypeSystem.BuiltIn.I4, GeneralPurposeRegister.EAX);
context.SetInstruction2(X86.Xchg, EAX, source, source, EAX);
context.AppendInstruction(X86.Mov, dest, EAX);
context.AppendInstruction2(X86.Xchg, source, EAX, EAX, source);
}
}
