Re: Any more graceful way to saturate adds?

On 17 Apr, 20:14, Terje Mathisen  <spamt...@[EMAIL PROTECTED]
> wrote:
> pete wrote:
> >> Was Terje's solution:
>
> >>   add dl,al     ; Carry set if it overflows!
> >>   sbb al,al     ; AL = 0xff if overflow
> >>   or dl,al      ; Turns any overflow into 0xff
>
> >> ...the right one?  I see overflow handling but not underflow...
>
[...]
>
> Anyway, unless clamping is very common, it is hard to beat the branch
> predictors!
>

I don't think the 808x CPU has a branch predictor. I guess one could
just add up the cycles used for each instruction on such an old CPU
and come up with the best performing code for various statistics of
the data. It should be pretty much deterministic (does it even use
cache memory?).

BR,
Danjel McGougan