private (LocalBuilder xDone, LocalBuilder yDone) EmitMoveNext(LocalBuilder xEnumerator, LocalBuilder yEnumerator, ILEmitter il)
{
// todo: 3. it's possible to use "not done" flag. it will simplify emitted code in _emitCheckIfLoopsAreDone.
il.Ceq(CallMethod(_moveNextMethod, LoadCaller(xEnumerator)),
Ldc_I4(0),
out var xDone)
.Ceq(CallMethod(_moveNextMethod, LoadCaller(yEnumerator)),
Ldc_I4(0),
out var yDone);
return(xDone, yDone);
}
public ILEmitter EmitCompareArrays(
ILEmitter il,
Type arrayType,
Type ownerType,
LocalBuilder xArray,
LocalBuilder yArray,
Label afterLoop)
{
// todo: 2. compare array lengths at the beginning
il.EmitArrayLength(arrayType, xArray, out var countX)
.EmitArrayLength(arrayType, yArray, out var countY)
.Ldc_I4(0)
.Stloc(typeof(int), out var index)
.DefineLabel(out var loopStart)
.DefineLabel(out var continueLoop)
.MarkLabel(loopStart);
using (il.LocalsScope()) {
il.Ceq(Ldloc(index), Ldloc(countX), out var isDoneX)
.Ceq(Ldloc(index), Ldloc(countY), out var isDoneY);
_emitCheckIfLoopsAreDone(il, isDoneX, isDoneY, afterLoop);
}
using (il.LocalsScope()) {
var arrays = new Dictionary <ushort, LocalBuilder>(2)
{
[Arg.X] = xArray,
[Arg.Y] = yArray
};
var itemVariable = new ArrayItemVariable(arrayType, ownerType, arrays, index);
var itemComparison = _resolver.GetComparisonEmitter(itemVariable);
return(il.Emit(
itemComparison.Emit(continueLoop),
itemComparison.EmitCheckForResult(continueLoop))
.MarkLabel(continueLoop)
.Add(Ldloc(index), Ldc_I4(1))
.Stloc(index)
.Br(loopStart));
}
}
private static void EmitCycleDetection(ILEmitter il, Type objectType) =>
il.Ceq(Ldc_I4(0), Or(TryAdd(Arg.SetX, Arg.X, objectType), TryAdd(Arg.SetY, Arg.Y, objectType)))
.Brfalse_S(out var next)
public ILEmitter Emit(ILEmitter il, Label _) => il.Ceq(_variable.Load(Arg.X), _variable.Load(Arg.Y));