Operator precedence between + and ?

[obones]

Hello,

Using Visual Studio to compile rtl_433, I get the following warning for this line:

Warning	C6336	Arithmetic operator has precedence over question operator, use parentheses to clarify intent.	

The code is this:

  msg->unparsed_length = (num_unparsed_bits / 8) + (num_unparsed_bits % 8) ? 1 : 0;

Right now, this means the addition is done and if it's not zero then unparsed_length will be 1 else 0.
This looks weird as the original intent, I sense that the point was to get the number of bytes required to store num_unparsed_bits bits.
If my feeling is right, then the operation can be written like this:

msg->unparsed_length = (num_unparsed_bits + 7) >> 3;

In my manchester_bitrow branch, I even have a macro to do it:

// Round up (NUM_BITS / 8)
#define NUM_BYTES(NUM_BITS) (((NUM_BITS) + 7) >> 3)

Let me know if you feel that a change should be done, I can create the PR.

[zuckschwerdt]

Yes canonical code for this is (x + 7) / 8 or (x + 7) >> 8 (one or the other might produce better code or confuse the compiler, but only if x is signed).
Please change those instances with prejudice.

[obones]

Done: #2378