public static void GenerateJumpIfEqual(ILGenerator ilGenerator, Type type, Label jumpTo, Action <ILGenerator> loadLeft, Action <ILGenerator> loadRight)
{
if (type == typeof(sbyte) || type == typeof(byte) || type == typeof(short) || type == typeof(ushort) ||
type == typeof(int) || type == typeof(uint) || type == typeof(long) || type == typeof(ulong) ||
type == typeof(float) || type == typeof(double) || type == typeof(bool))
{
loadLeft(ilGenerator);
loadRight(ilGenerator);
ilGenerator.BeqS(jumpTo);
return;
}
if (type.IsGenericType)
{
var genType = type.GetGenericTypeDefinition();
if (genType == typeof(Nullable <>))
{
var localLeft = ilGenerator.DeclareLocal(type);
var localRight = ilGenerator.DeclareLocal(type);
var hasValueMethod = type.GetMethod("get_HasValue");
var getValueMethod = type.GetMethod("GetValueOrDefault", Type.EmptyTypes);
loadLeft(ilGenerator);
ilGenerator.Stloc(localLeft);
loadRight(ilGenerator);
ilGenerator.Stloc(localRight);
var labelLeftHasValue = ilGenerator.DefineLabel();
var labelDifferent = ilGenerator.DefineLabel();
ilGenerator
.Ldloca(localLeft)
.Call(hasValueMethod)
.BrtrueS(labelLeftHasValue)
.Ldloca(localRight)
.Call(hasValueMethod)
.BrtrueS(labelDifferent)
.BrS(jumpTo)
.Mark(labelLeftHasValue)
.Ldloca(localRight)
.Call(hasValueMethod)
.BrfalseS(labelDifferent);
GenerateJumpIfEqual(
ilGenerator,
type.GetGenericArguments()[0],
jumpTo,
g => g.Ldloca(localLeft).Call(getValueMethod),
g => g.Ldloca(localRight).Call(getValueMethod));
ilGenerator.Mark(labelDifferent);
return;
}
}
var equalsMethod = type.GetMethod("Equals", new[] { type, type })
?? type.GetMethod("op_Equality", new[] { type, type });
if (equalsMethod != null)
{
loadLeft(ilGenerator);
loadRight(ilGenerator);
ilGenerator
.Call(equalsMethod)
.BrtrueS(jumpTo);
return;
}
throw new NotImplementedException(String.Format("Don't know how to compare type {0}", type));
}