C language operation Order Question.

[toalan]

I just have a quicky, i tried to google it but did not find much.

does a bit shift (<<) have higher priority over a power (^), I am trying to code up the Xtea encryption algorithim and I am not sure bout the order.

[toalan]

nm the (^) is an exclusive OR, now everything makes more sense

[toalan]

bitshift has higher priority than exclusive OR, Xtea here I come.

[devious9191]

Glad to be of help.

[Nyte]

When in doubt, add some brackets :)

[aquariaguy]

Is that even english?!

[gman]

Is that even english?!
He did say C. ;)

[toalan]

The syntax is C, I already solved all my issues and have successfully implemented xtea.

xtea is an encryption/decryption algorithim, it is supposed to be one of the few cyphers that has not been broken yet. I think xbox uses xtea or a slight variant of it. I was gonna do DES of AES encryption but they are not very computationally friendly. I am using xtea to encrypt my programs so people can not steal my work.

[CheapScotsman]

the average programmer can't remember the properity of operations (as your post atests to) so ... to be a good programmer, making your code more readable and unambiguous (without having to look it up) ...

Add the brackets !!!

[toalan]

I totally agree on adding brackets, I was looking at some reference code that had no brackets. Even the reference code said many people confuse the order of operation, but they still did not clarify.

[CheapScotsman]

Whew ... glad you are going to make it right. See how much easier the original author of that code would have made it ...

For future reference ... http://www.swansontec.com/sopc.htm and I wouldn't use the comma or Ternary Operator for the same reasons.

[toalan]

If by any chance anyone is interested in an XTEA bootloader for AVR, here is my work. It is about 80% complete.
http://www.14point7.com/AVR.htm