[sdiy] Quick C query

[Jason Proctor]

>On 21 November 2010 18:13, Tom Wiltshire <tom at electricdruid.net> wrote:
>>
>>  There's no need for the part with the "==(etc)", since C is just 
>>looking for a non-zero result to indicate true (simply processor 
>>zero flag clear, I hope).
>
>You're quite right of course (and cheater cheater too, if I re-read
>his paragraph on optimisation in the right light, I think). I blame
>rustiness.

with the provisor that you are actually testing for A *or* B. if 
you're testing for A *and* B, then you have to test that the masked 
result is equal to  A *or * B.

(i *think* this is what Tom means by "for a single flag" but i'm not sure.)