Talk:Overflow flag

Use non signed numbers in explanation!


pretty good explanation i don't care if there are no references lol it makes alot of sense please do not remove it just.... — Preceding unsigned comment added by 121.210.25.46 (talk) 10:42, 6 December 2011 (UTC)

indeed its the appended paper is really usefull, so dont remove it even though its doesnt fullfill all guidelines — Preceding unsigned comment added by 83.76.248.163 (talk) 12:55, 22 June 2012 (UTC)

Proof
I'd like to get an explaination and/or proof why OF is a XOR of C(n) (sign bit) and C(n-1). Can anyone help? It could also be helpful to the article. Galzigler (talk) 15:02, 5 September 2016 (UTC)

Bitwise operations clearing the V-flag makes sense.
The article currently says:

"Bitwise operations (and, or, xor, not, rotate) do not have a notion of signed overflow, so the defined value varies on different processor architectures. Some clear the bit unconditionally".

Clearing the V-flag is handy for example when using TEST EAX,EAX to test if the register is zero. Because the sign and zero flags are set by TEST and the V-flag is cleared you do not only test if EAX is zero but can also use JL(E) or JG(E) which use the V-flag. This may be too detailed for this article? 212.178.135.35 (talk) 13:04, 18 October 2022 (UTC) Martin.


 * OP writes: I phrased it briefly and more generally in the article.
 * 212.178.135.35 (talk) 10:07, 19 October 2022 (UTC) Martin.