private static bool BothWithNegativeSigns(BoxedExpression left, BoxedExpression right, out BoxedExpression minusLeft, out BoxedExpression minusRight, ConstFor GetConst)
{
if (left.IsUnary && left.UnaryOp == UnaryOperator.Neg)
{
// case -left, -right
if (right.IsUnary && right.UnaryOp == UnaryOperator.Neg)
{
minusLeft = left.UnaryArgument;
minusRight = right.UnaryArgument;
return(true);
}
Int32 value;
// case -left, constant
if (right.IsConstant && TryInt32Constant(right.Constant, out value))
{
minusLeft = left.UnaryArgument;
minusRight = GetConst(-value);
return(true);
}
}
else if (right.IsUnary && right.UnaryOp == UnaryOperator.Neg)
{
Int32 value;
// case constant, -right
if (left.IsConstant && TryInt32Constant(left.Constant, out value))
{
minusLeft = GetConst(-value);
minusRight = right.UnaryArgument;
return(true);
}
}
minusLeft = minusRight = null;
return(false);
}
private static BoxedExpression MakeItPrettier(BoxedExpression result, ConstFor GetConst)
{
BinaryOperator binop;
BoxedExpression left, right, mLeft, mRight;
if (result.IsBinaryExpression(out binop, out left, out right))
{
#region All the cases
switch (binop)
{
case BinaryOperator.Add:
case BinaryOperator.Add_Ovf:
case BinaryOperator.Add_Ovf_Un:
return(result);
case BinaryOperator.And:
return(BoxedExpression.Binary(BinaryOperator.And, MakeItPrettier(left, GetConst), MakeItPrettier(right, GetConst)));
case BinaryOperator.Ceq:
// -left == -right -> left == right
if (BothWithNegativeSigns(left, right, out mLeft, out mRight, GetConst))
{
return(BoxedExpression.Binary(BinaryOperator.Ceq, mLeft, mRight));
}
else
{
return(result);
}
case BinaryOperator.Cge:
// -left >= -right -> left <= right
if (BothWithNegativeSigns(left, right, out mLeft, out mRight, GetConst))
{
return(BoxedExpression.Binary(BinaryOperator.Cle, mLeft, mRight));
}
else
{
return(result);
}
case BinaryOperator.Cge_Un:
// -left >= -right -> left <= right
if (BothWithNegativeSigns(left, right, out mLeft, out mRight, GetConst))
{
return(BoxedExpression.Binary(BinaryOperator.Cle_Un, mLeft, mRight));
}
else
{
return(result);
}
case BinaryOperator.Cgt:
// -left > -right -> left < right
if (BothWithNegativeSigns(left, right, out mLeft, out mRight, GetConst))
{
return(BoxedExpression.Binary(BinaryOperator.Clt, mLeft, mRight));
}
else
{
return(result);
}
case BinaryOperator.Cgt_Un:
// -left > -right -> left < right
if (BothWithNegativeSigns(left, right, out mLeft, out mRight, GetConst))
{
return(BoxedExpression.Binary(BinaryOperator.Clt_Un, mLeft, mRight));
}
else
{
return(result);
}
case BinaryOperator.Cle:
// -left <= -right -> left >= right
if (BothWithNegativeSigns(left, right, out mLeft, out mRight, GetConst))
{
return(BoxedExpression.Binary(BinaryOperator.Cge, mLeft, mRight));
}
else
{
return(result);
}
case BinaryOperator.Cle_Un:
// -left <= -right -> left >= right
if (BothWithNegativeSigns(left, right, out mLeft, out mRight, GetConst))
{
return(BoxedExpression.Binary(BinaryOperator.Cge_Un, mLeft, mRight));
}
else
{
return(result);
}
case BinaryOperator.Clt:
// -left < -right -> left > right
if (BothWithNegativeSigns(left, right, out mLeft, out mRight, GetConst))
{
return(BoxedExpression.Binary(BinaryOperator.Cgt, mLeft, mRight));
}
else
{
return(result);
}
case BinaryOperator.Clt_Un:
// -left < -right -> left > right
if (BothWithNegativeSigns(left, right, out mLeft, out mRight, GetConst))
{
return(BoxedExpression.Binary(BinaryOperator.Cgt_Un, mLeft, mRight));
}
else
{
return(result);
}
case BinaryOperator.Cne_Un:
// -left != -right -> left != right
if (BothWithNegativeSigns(left, right, out mLeft, out mRight, GetConst))
{
return(BoxedExpression.Binary(BinaryOperator.Cne_Un, mLeft, mRight));
}
else
{
return(result);
}
case BinaryOperator.Div:
case BinaryOperator.Div_Un:
case BinaryOperator.Mul:
case BinaryOperator.Mul_Ovf:
case BinaryOperator.Mul_Ovf_Un:
return(result);
case BinaryOperator.Or:
return(BoxedExpression.Binary(BinaryOperator.Or, MakeItPrettier(left, GetConst), MakeItPrettier(right, GetConst)));
case BinaryOperator.Rem:
case BinaryOperator.Rem_Un:
case BinaryOperator.Shl:
case BinaryOperator.Shr:
case BinaryOperator.Shr_Un:
case BinaryOperator.Sub:
case BinaryOperator.Sub_Ovf:
case BinaryOperator.Sub_Ovf_Un:
case BinaryOperator.Xor:
return(result);
// Should be unreachable
default:
return(result);
}
#endregion
}
else
{
return(result);
}
}
