Reflector gets wrong decompiling result?

[deepzero]

First.

    IL_0000: ldarg.1      // load a
    IL_0001: ldarg.2      // load b (which is a reference)
    IL_0002: ldind.i4      //dereference b (bc it is is reference: int&)
    IL_0003: call         BitConverter::ToUInt() //call and put result on stack

then

    IL_0008: ldarg.2      // load b on stack for later use
    IL_0009: ldarg.2      // load b
    IL_000a: ldind.i4      //dereference it
    IL_000b: ldc.i4.4      //load interger-constant "4" to stack
    IL_000c: add           //add the values of b and "4" and put the result on the stack

SO now the stack looks like this:

<value: result of b+4>
<reference: b> (was loaded at IL_0008)
<value: return value of the BitConverter call>

Then the last piece of the puzzle:

    IL_000d: stind.i4   //store the result of  "b+4" in b

There now is just one entry on the stack:

<value: return value of the BitConverter call>

and finally return that last entry:

    IL_000e: ret

So in conclusion the method does two things: 1) b += 4 and 2) return BitConverter(). So reflector is right and the others are wrong. You should file a bug report.


A more literal decompilation would be:

    private uint e(byte[] a, ref int b)
    {
        uint32 tmp = BitConverter.ToUInt32(a, b);
        b += 4;
        return tmp;
    }

But you can trivially optimize that by eliminating the tmp variable.