Re: [PATCH 6/9] bsd-user: common routine do_freebsd_sysctl_oid for all sysctl variants

[Richard Henderson]

On 2/11/23 14:40, Warner Losh wrote:
> I was going to do something like:
>
> +    if (host_page_size != TARGET_PAGE_SIZE) {
> +        if (host_page_size > TARGET_PAGE_SIZE) {
> +            /* Scale up */
> +            pages *= host_page_size / TARGET_PAGE_SIZE;
> +        } else {
> +            /* Scale down with truncation */
> +            pages /= TARGET_PAGE_SIZE / host_page_size;
> +        }
> +    }
> in a helper function. Does multdiv64 replace that?

Yes, it uses a 128-bit intermediate result, so no overflow.
Obviously the above works as well, but perhaps premature optimization.


r~