Re: Need trapping
But in this case you'd want INTC, if it existed, as the arithmetic is unsigned. 0xffffffff + 7 is a negative plus a positive, so it doesn't set the overflow flag.
To be completely explicit: overflow indicates that you added two signed numbers and got a number of the wrong sign as a result. Such is the range of two's complement arithmetic, that can never occur if you add numbers of different signs. You can get overflow only if you add two negative numbers and the result is positive, or if you add two positive numbers and the result is negative.
Conversely, when adding two unsigned numbers such as here, the carry flag indicates that the true result is too large to fit into a single word.
Biting the hand that feeds IT
