C# Bitwise-or operator used on a sign-extended operand; consider casting to a smaller unsigned type first

Question

I know these warnings are probably pointless.. But anyway I could get rid of them?

I got 7 of these warnings.

Bitwise-or operator used on a sign-extended operand; consider casting to a smaller unsigned type first

This has something to do with the OR operator |

I highlighted what gives off the warnings.

int result = (int)ror((uint)(v76 ^ (v75 | 0x862D63D3)), (uint)(BitConverter.ToInt32(v4, 72) ^ 0x22));  int v11 = (int)rol((uint)(int)((v8 & v10 | ~v10 & 0xEFCDAAC9) + v3[2] - 1126481991), 17);  int v144 = (int)rol((uint)(int)((v141 & v143 | ~v143 & 0xEFCDAAC9) + v3[2] - 1126481991), 17);  int v77 = (int)(`BitConverter.ToInt32(v4, 52) | 0x96C35837`);   BitConverter.GetBytes((int)(v30 & 0x870DEA8A | v29)).CopyTo(v2, 32);  int temp24 |= (int)(BitConverter.ToInt32(v3, 48) | 0x96B4A1B4);  int v17 = (int)(BitConverter.ToInt32(v3, 12) | 0x83868A1D); 

Answer 1

A quick Web search shows the official documentation for the warning, which comes with an explanation:

The compiler implicitly widened and sign-extended a variable, and then used the resulting value in a bitwise OR operation. This can result in unexpected behavior.

The problem is that the expression v75 | 0x862D63D3 is of the form int | uint. This is computed by promoting both sides to long. If you really want sign extension, write (ulong)(long)v75 | 0x862D63D3. If you really want zero-extension, then write (uint)v75 |0x862D63D3.

class Program {  public static void Main()  {   int v75 = int.MinValue;   System.Console.WriteLine("{0:x}", v75 | 0x862D63D3);   System.Console.WriteLine("{0:x}", (ulong)(long)v75 | 0x862D63D3);   System.Console.WriteLine("{0:x}", (uint)v75 | 0x862D63D3);  } } 

This program prints

ffffffff862d63d3 ffffffff862d63d3 862d63d3 

As you can see, the compiler defaults to the first interpretation, which is probably not what you want.

Answer 2

Try casting v75 and other variables being ORed with unsigned hex values to uint:

((uint)v75 | 0x862D63D3) 

or declare the variables as uint instead of int.