[Mesa-dev] [PATCH] i965/urb: fixes division by zero

[Matt Turner]

On Mon, May 16, 2016 at 4:27 PM, Ardinartsev Nikita <ardinar23 at gmail.com> wrote:
> Fixes regression introduced by af5ca43f2676bff7499f93277f908b681cb821d0
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=95419

Thank you very much for the patch. It is

Reviewed-by: Matt Turner <mattst88 at gmail.com>

I'll commit it shortly.

> ---
>  src/mesa/drivers/dri/i965/gen7_urb.c | 24 +++++-------------------
>  1 file changed, 5 insertions(+), 19 deletions(-)
>
> diff --git a/src/mesa/drivers/dri/i965/gen7_urb.c b/src/mesa/drivers/dri/i965/gen7_urb.c
> index a412a42..4194541 100644
> --- a/src/mesa/drivers/dri/i965/gen7_urb.c
> +++ b/src/mesa/drivers/dri/i965/gen7_urb.c
> @@ -292,25 +292,11 @@ gen7_upload_urb(struct brw_context *brw)
>     if (remaining_space > total_wants)
>        remaining_space = total_wants;
>     if (remaining_space > 0) {
> -      unsigned vs_additional = (unsigned)
> -         roundf(vs_wants * (((float) remaining_space) / total_wants));
> -      vs_chunks += vs_additional;
> -      remaining_space -= vs_additional;
> -      total_wants -= vs_wants;
> -
> -      unsigned hs_additional = (unsigned)
> -         round(hs_wants * (((double) remaining_space) / total_wants));
> -      hs_chunks += hs_additional;
> -      remaining_space -= hs_additional;
> -      total_wants -= hs_wants;
> -
> -      unsigned ds_additional = (unsigned)
> -         round(ds_wants * (((double) remaining_space) / total_wants));
> -      ds_chunks += ds_additional;
> -      remaining_space -= ds_additional;
> -      total_wants -= ds_wants;
> -
> -      gs_chunks += remaining_space;
> +      float ratio = ((float) remaining_space) / total_wants;
> +      vs_chunks += roundf(vs_wants * ratio);
> +      hs_chunks += roundf(hs_wants * ratio);
> +      ds_chunks += roundf(ds_wants * ratio);
> +      gs_chunks += roundf(gs_wants * ratio);

I plan to change these roundf() calls to lroundf().