12.4, reading volatile side effect

[misra-c]

The && operator does not evaluate its right-hand operand if the left-hand operand evaluates to False. Therefore any side-effect in the right-hand expression will not occur if the left-hand expression evaluates to False.

Re-writing the code ensures that the volatile is always read.

Code:

#define REGISTER            (*((uword volatile *) 0xEA2CU))
uword reg;
reg = REGISTER;             /* volatile read will always happen */
if(xxx && (reg > 0))

whereas this is not the case in the original code

Code:

#define REGISTER            (*((uword volatile *) 0xEA2CU))
if (xxx && REGISTER)        /* volatile read will only occur if xxx evaluates to True */