/// <summary>
/// Pops the value on the stack, converts it to an integer, then pushes the integer result
/// onto the stack.
/// </summary>
/// <param name="generator"> The IL generator. </param>
/// <param name="fromType"> The type to convert from. </param>
public static void ToInteger(ILGenerator generator, PrimitiveType fromType)
{
// Check that a conversion is actually necessary.
if (fromType == PrimitiveType.Int32 || fromType == PrimitiveType.UInt32 || fromType == PrimitiveType.Bool)
{
return;
}
switch (fromType)
{
case PrimitiveType.Undefined:
case PrimitiveType.Null:
// Converting from undefined or null produces 0.
generator.Pop();
generator.LoadInt32(0);
break;
case PrimitiveType.Number:
// Converting from a number produces the following:
// Any number between -2147483648 and +2147483647 -> itself
// Any number smaller than -2147483648 -> -2147483648
// Any number larger than +2147483647 -> +2147483647
// NaN -> 0
// bool isPositiveInfinity = input > 2147483647.0
var isPositiveInfinity = generator.CreateTemporaryVariable(typeof(bool));
generator.Duplicate();
generator.LoadDouble(2147483647.0);
generator.CompareGreaterThan();
generator.StoreVariable(isPositiveInfinity);
// bool notNaN = input == input
var notNaN = generator.CreateTemporaryVariable(typeof(bool));
generator.Duplicate();
generator.Duplicate();
generator.CompareEqual();
generator.StoreVariable(notNaN);
// input = (int)input
// Infinity -> -2147483648
// -Infinity -> -2147483648
// NaN -> -2147483648
generator.ConvertToInteger();
// input = input & -((int)notNaN)
generator.LoadVariable(notNaN);
generator.Negate();
generator.BitwiseAnd();
// input = input - (int)isPositiveInfinity
generator.LoadVariable(isPositiveInfinity);
generator.Subtract();
// The temporary variables are no longer needed.
generator.ReleaseTemporaryVariable(notNaN);
generator.ReleaseTemporaryVariable(isPositiveInfinity);
break;
case PrimitiveType.String:
case PrimitiveType.ConcatenatedString:
case PrimitiveType.Any:
case PrimitiveType.Object:
// Otherwise, fall back to calling TypeConverter.ToInteger()
generator.Call(ReflectionHelpers.TypeConverter_ToInteger);
break;
default:
throw new NotImplementedException(string.Format("Unsupported primitive type: {0}", fromType));
}
}
/// <summary>
/// Pops the value on the stack, converts it to an integer, then pushes the integer result
/// onto the stack.
/// </summary>
/// <param name="generator"> The IL generator. </param>
/// <param name="fromType"> The type to convert from. </param>
public static void ToInteger(ILGenerator generator, PrimitiveType fromType)
{
// Check that a conversion is actually necessary.
if (fromType == PrimitiveType.Int32 || fromType == PrimitiveType.UInt32 || fromType == PrimitiveType.Bool)
return;
switch (fromType)
{
case PrimitiveType.Undefined:
case PrimitiveType.Null:
// Converting from undefined or null produces 0.
generator.Pop();
generator.LoadInt32(0);
break;
case PrimitiveType.Number:
// Converting from a number produces the following:
// Any number between -2147483648 and +2147483647 -> itself
// Any number smaller than -2147483648 -> -2147483648
// Any number larger than +2147483647 -> +2147483647
// NaN -> 0
// bool isPositiveInfinity = input > 2147483647.0
var isPositiveInfinity = generator.CreateTemporaryVariable(typeof(bool));
generator.Duplicate();
generator.LoadDouble(2147483647.0);
generator.CompareGreaterThan();
generator.StoreVariable(isPositiveInfinity);
// bool notNaN = input == input
var notNaN = generator.CreateTemporaryVariable(typeof(bool));
generator.Duplicate();
generator.Duplicate();
generator.CompareEqual();
generator.StoreVariable(notNaN);
// input = (int)input
// Infinity -> -2147483648
// -Infinity -> -2147483648
// NaN -> -2147483648
generator.ConvertToInteger();
// input = input & -((int)notNaN)
generator.LoadVariable(notNaN);
generator.Negate();
generator.BitwiseAnd();
// input = input - (int)isPositiveInfinity
generator.LoadVariable(isPositiveInfinity);
generator.Subtract();
// The temporary variables are no longer needed.
generator.ReleaseTemporaryVariable(notNaN);
generator.ReleaseTemporaryVariable(isPositiveInfinity);
break;
case PrimitiveType.String:
case PrimitiveType.ConcatenatedString:
case PrimitiveType.Any:
case PrimitiveType.Object:
// Otherwise, fall back to calling TypeConverter.ToInteger()
generator.Call(ReflectionHelpers.TypeConverter_ToInteger);
break;
default:
throw new NotImplementedException(string.Format("Unsupported primitive type: {0}", fromType));
}
}
