Re: [gpsim-devel] overflow flag

[Eric S. <er...@br...>]

Scott wrote:
> Another way to write it in C is:
>    v = ( ((~sum & a & b) | (sum & ~a & ~b)) & 0x80) ? 1 : 0;

I've verified that this produces identical results to my expression.

> A perhaps somewhat simpler expression is:
>    v = ( ((sum ^ ~b) & (a ^ ~b)) & 0x80) ? 1 : 0;

Does not seem to give the same results.  An error in simplification?
Or I suppose it could be an error in my C test program.  I could send
you the program if you like, not that it's particularly complicated.

Eric