public override void WriteTo(ITextOutput output, ILAstWritingOptions options)
{
WriteILRange(output, options);
output.Write(OpCode);
output.Write("." + BinaryNumericInstruction.GetOperatorName(Operator));
if (CompoundAssignmentType == CompoundAssignmentType.EvaluatesToNewValue)
{
output.Write(".new");
}
else
{
output.Write(".old");
}
if (CheckForOverflow)
{
output.Write(".ovf");
}
if (Sign == Sign.Unsigned)
{
output.Write(".unsigned");
}
else if (Sign == Sign.Signed)
{
output.Write(".signed");
}
output.Write('(');
Target.WriteTo(output, options);
output.Write(", ");
Value.WriteTo(output, options);
output.Write(')');
}
public NumericCompoundAssign(BinaryNumericInstruction binary, ILInstruction target, ILInstruction value, IType type, CompoundAssignmentType compoundAssignmentType)
: base(OpCode.NumericCompoundAssign, compoundAssignmentType, target, value)
{
Debug.Assert(IsBinaryCompatibleWithType(binary, type));
this.CheckForOverflow = binary.CheckForOverflow;
this.Sign = binary.Sign;
this.LeftInputType = binary.LeftInputType;
this.RightInputType = binary.RightInputType;
this.UnderlyingResultType = binary.UnderlyingResultType;
this.Operator = binary.Operator;
this.IsLifted = binary.IsLifted;
this.type = type;
this.AddILRange(binary);
Debug.Assert(compoundAssignmentType == CompoundAssignmentType.EvaluatesToNewValue || (Operator == BinaryNumericOperator.Add || Operator == BinaryNumericOperator.Sub));
Debug.Assert(IsValidCompoundAssignmentTarget(Target));
}
/// <summary>
/// Gets whether the specific binary instruction is compatible with a compound operation on the specified type.
/// </summary>
internal static bool IsBinaryCompatibleWithType(BinaryNumericInstruction binary, IType type)
{
if (binary.IsLifted)
{
if (!NullableType.IsNullable(type))
{
return(false);
}
type = NullableType.GetUnderlyingType(type);
}
if (type.Kind == TypeKind.Unknown)
{
return(false); // avoid introducing a potentially-incorrect compound assignment
}
else if (type.Kind == TypeKind.Enum)
{
switch (binary.Operator)
{
case BinaryNumericOperator.Add:
case BinaryNumericOperator.Sub:
case BinaryNumericOperator.BitAnd:
case BinaryNumericOperator.BitOr:
case BinaryNumericOperator.BitXor:
break; // OK
default:
return(false); // operator not supported on enum types
}
}
else if (type.Kind == TypeKind.Pointer)
{
switch (binary.Operator)
{
case BinaryNumericOperator.Add:
case BinaryNumericOperator.Sub:
// ensure that the byte offset is a multiple of the pointer size
return(PointerArithmeticOffset.Detect(
binary.Right,
((PointerType)type).ElementType,
checkForOverflow: binary.CheckForOverflow
) != null);
default:
return(false); // operator not supported on pointer types
}
}
if (binary.Sign != Sign.None)
{
if (type.IsCSharpSmallIntegerType())
{
// C# will use numeric promotion to int, binary op must be signed
if (binary.Sign != Sign.Signed)
{
return(false);
}
}
else
{
// C# will use sign from type
if (type.GetSign() != binary.Sign)
{
return(false);
}
}
}
// Can't transform if the RHS value would be need to be truncated for the LHS type.
if (Transforms.TransformAssignment.IsImplicitTruncation(binary.Right, type, null, binary.IsLifted))
{
return(false);
}
return(true);
}